Acinetobacter

J Ind Microbiol Biotechnol, 2001 Jun, 26(6), 333 - 40
Phosphate uptake and release by Acinetobacter johnsonii in continuous culture and coupling of phosphate release to heavy metal accumulation; Boswell CD et al.; A strain of polyphosphate-synthesizing, phosphate-releasing Acinetobacter johnsonii was isolated from a wastewater treatment plant operating enhanced biological phosphate removal (EBPR) and was used to remove La(3+) from solution via precipitation of cell-bound LaPO(4) . The effect of repeated aerobic-anaerobic cycles on the carbon and phosphate metabolism of the organism was studied in attempts to promote increased phosphate flux using a three-stage, continuous bioreactor comprising aerobic, anaerobic and settling vessels . The bioreactor was operated in two modes: In flow-through mode, cells were grown aerobically with acetate as the sole carbon source, promoting excess phosphate uptake (up to 5.0 mmol/l=3.0 mmol/g protein) . Cells were diluted into the anaerobic vessel where phosphate was released (up to 1.0 mmol/l=0.3 mmol/g protein), and thence to waste . The system was initially operated to steady state in flow-through mode, then switched to recycle mode . Here the anaerobic vessel output passed to a settling vessel from which settled cells were returned to the aerobic vessel . Carbon source (acetate) was supplied only to the anaerobic vessel; increased anaerobic acetate uptake was observed during recycle, which was sustained when the system was returned to flow-through mode and was related to increased cellular lipid inclusions by flow cytometry and electron microscopy . These phenomena may represent adaptation of cells to aerobic-anaerobic cycling with aerobic carbon/energy limitation . Addition of La(3+) to the anaerobic vessel during recycle mode promoted removal of 95% of the La(3+) from a 0.1 to 0.3 mM (14-42 ppm) solution at the expense of biogenic phosphate.

Appl Environ Microbiol, 2001 Oct, 67(10), 4817 - 27
Cloning and genetic characterization of dca genes required for beta-oxidation of straight-chain dicarboxylic acids in Acinetobacter sp . strain ADP1; Parke D et al.; A previous study of deletions in the protocatechuate (pca) region of the Acinetobacter sp . strain ADP1 chromosome revealed that genes required for utilization of the six-carbon dicarboxylic acid, adipic acid, are linked to the pca structural genes . To investigate the genes involved in adipate catabolism, a 33.8-kb SacI fragment, which corrects a deletion spanning this region, was cloned . In addition to containing known pca, qui, and pob genes (for protocatechuate, quinate, and 4-hydroxybenzoate dissimilation), clone pZR8000 contained 10 kb of DNA which was the subject of this investigation . A mutant strain of Escherichia coli DH5alpha, strain EDP1, was isolated that was able to utilize protocatechuate and 4-hydroxybenzoate as growth substrates when EDP1 cells contained pZR8000 . Sequence analysis of the new region of DNA on pZR8000 revealed open reading frames predicted to be involved in beta-oxidation . Knockouts of three genes implicated in beta-oxidation steps were introduced into the chromosome of Acinetobacter sp . strain ADP1 . Each of the mutants was unable to grow with adipate . Because the mutants were affected in their ability to utilize additional saturated, straight-chain dicarboxylic acids, the newly discovered 10 kb of DNA was termed the dca (dicarboxylic acid) region . Mutant strains included one with a deletion in dcaA (encoding an acyl coenzyme A {acyl-CoA} dehydrogenase homolog), one with a deletion in dcaE (encoding an enoyl-CoA hydratase homolog), and one with a deletion in dcaH (encoding a hydroxyacyl-CoA dehydrogenase homolog) . Data on the dca region should help us probe the functional significance and interrelationships of clustered genetic elements in this section of the Acinetobacter chromosome.

Laryngoscope, 2001 Aug, 111(8), 1333 - 7
Comparison of antral tap with endoscopically directed nasal culture; Casiano RR et al.; OBJECTIVES/HYPOTHESIS: The diagnosis of acute bacterial rhinosinusitis continues to generate controversy in critically ill patients . The efficacy of endoscopically directed cultures in these patients is unknown . We compared antral tap (AT) with endoscopic tissue culture (ETC) of the osteomeatal complex in an intensive care unit (ICU) setting . METHODS: Twenty patients admitted to a surgical/trauma ICU were evaluated by AT and ENB for the presence of rhinosinusitis . All patients had 1) a fever of unknown origin without resolution on empiric antibiotic therapy for > or =48 hrs; 2) other sources of fever ruled out; 3) computed tomography scan evidence of mucoperiosteal thickening +/- sinus air/fluid levels; and 4) attempt at conservative treatment with topical decongestants and removal of all nasal intubation . Microbiologic data were collected and analyzed for any statistical difference between groups . RESULTS: A total of 29 sides underwent simultaneous tap and endoscopically directed tissue culture . The mean age was 40 years (range, 23-77 y) with 85% being males . Fifteen of 20 (75%) patients in the AT group were culture-positive . Of the 49 isolates from the AT, 55% yielded Gram-negative bacilli (Acinetobacter sp . 37%) and 45% yielded Gram-positive cocci . The ETC group was culture-positive in 18 of 20 (90%) patients . Of the 52 isolates from the ETC, Gram-negative bacilli were found in 58% (Acinetobacter sp . 33%) and 42% yielded Gram-positive cocci . The ETCs were culture-positive in all but 1 patient with positive taps . There appeared to be a concordance between AT and ETC in 60% of the patients . In five instances (25%), results of the AT or ETC changed ICU management . Two patients ultimately required sinus surgery . CONCLUSIONS: Sinus taps and/or endoscopically directed tissue cultures led to a change in ICU care in 25% of ICU patients studied . In patients with fever of unknown origin and computed tomography evidence of sinusitis, an antral tap continues to provide important information concerning maxillary sinusitis . However, ETC may give as good a representation of the microbiology and secondary inflammatory changes responsible for bacterial ICU rhinosinusitis causing fever of unknown origin . Further study on a larger group of patients is needed.

Environ Sci Technol, 2001 Sep 1, 35(17), 3462 - 7
Hydrogen and carbon isotope fractionation during aerobic biodegradation of benzene; Hunkeler D et al.; The main aim of the study was to evaluate hydrogen and carbon isotope fractionation during biodegradation of benzene as a possible tool to trace the process in contaminated environments . Aerobic biodegradation of benzene by two bacterial isolates, Acinetobacter sp . and Burkholderia sp., was accompanied by significant hydrogen and carbon isotope fractionation with hydrogen isotope enrichment factors of -12.8 +/- 0.7 per thousand and -11.2 +/- 1.8 per thousand, respectively, and average carbon isotope enrichment factors of -1.46 +/- 0.06 per thousand and -3.53 +/- 0.26 per thousand, respectively . Inorganic carbon produced by Acinetobacter sp . was depleted in 13C by 3.6-6.2 per thousand as compared to the initial delta13C of benzene, while the produced biomass was enriched in 13C by 3.8 per thousand . The secondary aim was to determine isotope ratios of benzenes from different manufacturers with regard to the use of isotopes for source differentiation . While two of the four analyzed benzenes had similar delta13C values, each of them had a distinct delta2H-delta13C pair and delta2H values spread over a range of 66.5 per thousand . Thus, combined analyses of hydrogen and carbon isotopes may be a more promising approach to trace sources and/or biodegradation of benzene than measuring carbon isotopes only.

Curr Infect Dis Rep, 2001 Oct, 3(5), 440 - 444
The Increasing Role of Acinetobacter Species As Nosocomial Pathogens; Bergogne-Berezin E; Among gram-negative organisms playing a significant role in nosocomial infections, Acinetobacter species have attracted increasing attention in intensive care units during the past two decades . Acinetobacter species are implicated in a wide spectrum of infections (eg, bacteremia, nosocomial pneumonia, urinary tract infections, secondary meningitis, superinfections in burn patients) . One of the most striking features of Acinetobacter species is their extraordinary ability to develop multiple resistance mechanisms against major antibiotic classes . They have become resistant to broad-spectrum beta-lactams (third-generation cephalosporins, carboxypenicillins, and increasingly to carbapenems); they produce a wide range of aminoglycoside-inactivating enzymes; and most strains are resistant to fluoroquinolones . In Acinetobacter nosocomial infections, the major problems confronting clinicians in intensive care units are related to the severity of Acinetobacter nosocomial infections and to resistance to major antibiotic classes of these organisms.

Kansenshogaku Zasshi, 2001 Aug, 75(8), 662 - 70
{Antimicrobial activities and mechanisms of carbapenem resistance in clinical isolates of carbapenem-resistant Pseudomonas aeruginosa and Acinetobacter spp.}; Sugino Y et al.; We tested the antimicrobial activities of meropenem (MEPM), imipenem (IPM), panipenem (PAPM), piperacillin (PIPC), cefepime (CFPM), aztreonam (AZT), amikacin (AMK), and levofloxacin (LVFX) against 106 clinical Pseudomonas aeruginosa isolates and 64 clinical Acinetobacter spp . isolates with reduced susceptibility to carbapenems . Using NCCLS breakpoints, the percentages of P . aeruginosa strains susceptible to AMK and Acinetobacter spp . strains susceptible to LVFX were found to be 51.1% and 55.6%, respectively, which represented the highest activity among 8 antimicrobial agents in each organism . Referring to the correlations among MICs of carbapenems, MEPM showed a higher activity than IPM and PAPM in both organisms; 29 of the 94 strains (30.9%) of IPM-resistant P . aeruginosa were susceptible to MEPM . Further study for resistance mechanisms to carbapenems by the disk diffusion method using 2-mercaptopropionic acid revealed that 8 of the 64 Acinetobacter spp . isolates (12.5%) were metallo-beta-lactamase producers, while none of 106 P . aeruginosa isolates were metallo-beta-lactamase producers . PCR analysis using blaIMP-specific primers confirmed that 4 of the 8 metallo-beta-lactamase-producing Acinetobacter spp . isolates detected by the disk diffusion method were carrying the blaIMP gene . The identification of metallo-beta-lactamase-producing Acinetobacter spp . isolates implies that metallo-beta-lactamase genes have been disseminated among various gram-negative pathogens.

Eur J Intern Med, 2001 Sep, 12(5), 425 - 429
Acinetobacter bacteraemia in a teaching hospital, 1989-1998; Valero C et al.; Background: The mortality rate from bacteraemia is one of the highest among infections in hospitals, especially in the intensive care unit (ICU) . Recently, an increase in nosocomial bacteraemia caused by gram-negative resistant pathogens has been observed . In this work we review the clinical and laboratory findings of adult patients with Acinetobacter bacteraemia in order to identify risk factors associated with mortality . Methods: A retrospective review of the medical records of patients with Acinetobacter bacteraemia identified by blood cultures from the Diagnostic Microbiology Laboratory was conducted between January 1989 and March 1998 . Results: We identified 59 cases of Acinetobacter bacteraemia . Most of the infections (71%) were nosocomial; the majority occurred in the Department of Internal Medicine (28.8%), followed by Haematology (27%) and the ICU (23%) . A . lwoffii was isolated in 52.5% of cases and A . baumannii in 47.5% . The related mortality was 17% . Staying in the ICU was associated with A . baumannii bacteraemia (P<0.004) . An intravascular catheter was the leading source of infection (37%) . Main risk factors were mechanical ventilation (28%), parenteral nutrition (23%) and the presence of a urinary catheter (22%) . In the multivariate analysis the independent prognostic factors for mortality were the presence of shock (P<0.05) and the severity of the underlying disease, according to the classification of McCabe (P<0.05) . Conclusions: The incidence of Acinetobacter bacteraemia has increased in the last decade, mainly since 1995 . The development of septic shock and the severity of the underlying disease appear to be associated with an increase in mortality.

J Med Assoc Thai, 2001 Jun, 84(6), 910 - 3
Successful treatment of late onset infection due to multi-drug resistant Acinetobacter Lwoffii in a low birth weight neonate using ciprofloxacin; Chotigeat U et al.; This report presents the case of a low birth weight neonate with multidrug-resistant Acinetobacter Lwoffii infection who was successfully treated with ciprofloxacin and co-trimoxazole . Use of ciprofloxacin in pediatric populations was reviewed . The infant responded to the antibiotic regimen with sterilized cerebrospinal fluid with no adverse effects attributable to the ciprofloxacin . Although ciprofloxacin has been found to cause irreversible damage to cartilage in laboratory animals, a review of the literature found that this complication rarely occurs in pediatric patients . Ciprofloxacin has been found to be effective in the treatment of multidrug-resistant gram negative infections in pediatric patients, including premature infants . Ciprofloxacin should be considered in the treatment of neonatal infection caused by multidrug-resistant gram-negative organisms.

Microbios, 2001, 106 Suppl 2, 97 - 104
In vitro effect of ampicillin/sulbactam on Acinetobacter species; Hostacka A; The effects of subinhibitory concentrations (sub-MIC) of ampicillin/sulbactam (AMP/sulbactam), on the surface hydrophobicity and the lipase activity of ten Acinetobacter strains, were examined . The alterations in the activities studied were strain and drug concentration dependent . Most of the strains treated showed a decrease in surface hydrophobicity to a different extent . The hydrophobic character of three strains exposed to 1/4 or 1/8 of the MIC of the antibiotic was changed to a hydrophilic state . The majority of Acinetobacter strains after treatment with antibiotic possessed increased lipolytic activity . AMP/sulbactam even at sub-MIC may interfere with possible virulence factors of Acinetobacter strains in vitro.

Natl Med J India, 2001 Jul-Aug, 14(4), 204 - 8
Distribution and in vitro antimicrobial susceptibility of Acinetobacter species on the skin of healthy humans; Patil JR et al.; BACKGROUND: Acinetobacter spp . are ubiquitous in the environment and have emerged as important nosocomial pathogens . The distribution of Acinetobacter spp . In some temperate European countries has been reported . However, similar data from a tropical country such as India are not available . METHODS: Six body sites (antecubital fossa, axilla, forehead with hairline, neck, outer surface of nose and toe webs) from men and women volunteers were sampled with saline-soaked cotton swabs enriched in Baumann's enrichment medium . The isolates were identified to the genus level by chromosomal DNA transformation assay and to the species level by a 16-test biochemical system . The minimum inhibitory concentration for 39 antibiotics was determined by the two-fold agar dilution method . RESULTS: Seven genospecies of Acinetobacter were found at 6 body sites on healthy human skin . Acinetobacter lwoffii was the most dominant comprising 40% of the total number of isolates, followed by A . junii (35%) and A . haemolyticus (16.5%) . The antecubital fossa had the highest colonization frequency (48.5%) . The overall positivity rate of samples was higher from women (26.3%) compared to men volunteers (25%) . Only two Acinetobacter genospecies 1-3 isolates were isolated while no A . radioresistens were isolated . Susceptibility testing revealed no major differences among the 7 Acinetobacter spp . tested . Fluoroquinolones were the most active, while low-to-intermediate resistance was exhibited towards beta-lactams and aminoglycosides . Acinetobacter spp . isolated from the skin showed susceptibility to commonly used antibiotics . CONCLUSION: Seven Acinetobacter genospecies were isolated from 6 different body sites from the skin of healthy human volunteers . Acinetobacter lwoffii was the dominant isolate . The rate of skin carriage was higher in men than in women and the maximally colonized site was the antecubital fossa . All the genospecies displayed susceptibility to most of the commonly used antimicrobials.

Icarus, 1990, 85, 241 - 56
Microbial metabolism of tholin; Stoker CR et al.; In this paper, we show that a wide variety of common soil bacteria are able to obtain their carbon and energy needs from tholin (a class of complex organic heteropolymers thought to be widely distributed through the solar system; in this case tholin was produced by passage of electrical discharge through a mixture of methane, ammonia, and water vapor) . We have isolated aerobic, anaerobic, and facultatively anaerobic bacteria which are able to use tholin as a sole carbon source . Organisms which metabolize tholin represent a variety of bacterial genera including Clostridium, Pseudomonas, Bacillus, Acinetobacter, Paracoccus, Alcaligenes, Micrococcus, Corynebacterium, Aerobacter, Arthrobacter, Flavobacterium, and Actinomyces . Aerobic tholin-using bacteria were first isolated from soils containing unusual or sparse carbon sources . Some of these organisms were found to be facultatively anaerobic . Strictly anaerobic tholin-using bacteria were isolated from both carbon-rich and carbon-poor anaerobic lake muds . In addition, both aerobic and anaerobic tholin-using bacteria were isolated from common soil collected outside the laboratory building . Some, but not all, of the strains that were able to obtain carbon from tholin were also able to obtain their nitrogen requirements from tholin . Bacteria isolated from common soils were tested for their ability to obtain carbon from the water-soluble fraction, the ethanol-soluble fraction, and the water/ethanol-insoluble fraction of the tholin . Of the 3.5 x 10(7) bacteria isolated per gram of common soils, 1.7, 0.5, and 0.2%, respectively, were able to obtain their carbon requirements from the water-soluble fraction, the ethanol-soluble fraction and the water/ethanol-insoluble fraction of the tholin . The palatability of tholins to modern microbes may have implications for the early evolution of microbial life on Earth . Tholins may have formed the base of the food chain for an early heterotrophic biosphere before the evolution of autotrophy on the early Earth . Where tholins are present on other planets, they could possibly be metabolized by contaminant microorganisms transported to these bodies via spacecraft . Thus, the presence of tholins should be taken into account when evaluating the planetary quarantine requirements for probes to other planets.

BMC Microbiol . 2001;1(1):16 . Epub 2001 Aug 09.
Monoclonal antibodies against the iron regulated outer membrane Proteins of Acinetobacter baumannii are bactericidal; Goel VK et al.; BACKGROUND: Iron is an important nutrient required by all forms of life.In the case of human hosts,the free iron availability is 10(-18) M,which is far less than what is needed for the survival of the invading bacterial pathogen.To survive in such conditions, bacteria express new proteins in their outer membrane and also secrete iron chelators called siderophores . RESULTS/ DISCUSSION: Acinetobacter baumannii ATCC 19606, a nosocomial pathogen which grows under iron restricted conditions, expresses four new outer membrane proteins,with molecular weight ranging from 77 kDa to 88 kDa, that are called Iron Regulated Outer Membrane Proteins (IROMPs) . We studied the functional and immunological properties of IROMPs expressed by A.baumanii ATCC 19606.The bands corresponding to IROMPs were eluted from SDS-PAGE and were used to immunize BALB/c mice for the production of monoclonal antibodies . Hybridomas secreting specific antibodies against these IROMPs were selected after screening by ELISA and their reactivity was confirmed by Western Blot . The antibodies then generated belonged to IgM isotype and showed bactericidical and opsonising activities against A.baumanii in vitro.These antibodies also blocked siderophore mediated iron uptake via IROMPs in bacteria . CONCLUSION: This proves that iron uptake via IROMPs,which is mediated through siderophores,may have an important role in the survival of A.baumanii inside the host,and helps establishing the infection.

Prikl Biokhim Mikrobiol, 2001 Jul-Aug, 37(4), 398 - 404
{Degradation of mineral oil by Acinetobacter calcoaceticus strain}; Pleshakova EV et al.; The Acinetobacter calcoaceticus strain TM-31 has been isolated from a microbial assemblage of a pilot plant purifying waste water polluted with mineral oil . This strain is capable of efficient degradation of components of mineral oil (alkanes, isoalkanes, and alkyl residues of the naphthene and arene fraction . The strain bears stably inherited plasmids of sizes 120, 9, and 8 kb, which can be transferred into plasmid-free cells of the parental strain and into bacteria of the genus Pseudomonas and ensure the degradation of hexadecane and mineral oil.

Clin Infect Dis, 2001 Oct 1, 33(7), 939 - 46 Epub 2001 Aug 22.
Risk factors for Acinetobacter baumannii nosocomial bacteremia in critically ill patients: a cohort study; Garcia-Garmendia JL et al.; Nosocomial bacteremia caused by Acinetobacter baumannii (AB) is of increasing concern in critically ill patients, and the risk factors for this infection are not well established . An inception cohort study in a 40-bed medical and surgical intensive care unit (ICU) at a single institution was conducted during a 2-year period to determine the risk factors for AB nosocomial bacteremia . Risk factors related to the underlying diseases, the clinical picture at admission, and those acquired during the stay in the ICU were recorded upon admission and daily throughout the ICU stay . We defined an "invasive procedures index" as the number of invasive procedures performed every day during the ICU stay before the onset of AB bacteremia divided by the number of days in the ICU before the onset of AB bacteremia . Risk factors that were independently associated with AB bacteremia were immunosuppression, unscheduled admission to the hospital, respiratory failure at ICU admission, previous antimicrobial therapy, previous sepsis in the ICU, and the invasive procedures index.

Pediatr Surg Int, 2001 Jul, 17(5-6), 390 - 5
Bacterial cholangitis in patients with biliary atresia: impact on short-term outcome; Wu ET et al.; Bacterial cholangitis (BC) is a common complication in patients with biliary atresia (BA) and is characterized by fever, acholic stools and positive blood cultures . The diagnosis is often empirical because the yield of blood cultures is low . It is difficult to differentiate BC from other febrile episodes . In order to characterize the clinical and laboratory features of BC in patients with BA, identify risk factors, and correlate cholangitis with outcome, 37 patients with BA from 1993 to 1998 who underwent a Kasai operation in our hospital were studied . The follow-up period ranged from 6 to 59 months . A total of 107 febrile episodes were documented in these patients . The diagnostic criteria for cholangitis were fever, increased jaundice, or acholic stools . The clinical features, laboratory data, results of bacterial cultures, and outcomes were analyzed retrospectively . A total of 107 febrile episodes, including 78 bouts of cholangitis and 29 non-cholangitis infections, were found in 34 patients . Patients with BC had higher postoperative bilirubin levels (P = 0.02) and less frequent use of prophylactic antibiotics (P = 0.05) than those with non-cholangitis infections . Abnormal white blood cell counts (> 12,000 or <4,000 mm3) tended to be present in patients with BC (P = 0.08) . There were no statistical differences in the risk factors and laboratory data between culture-positive (n = 16) and -negative (n = 62) cholangitis cases . The occurrence of cholangitis significantly reduced survival in both patients with good (P = 0.03) and inadequate bile flow (P = 0.03) . All 9 patients who had never had cholangitis survived during the follow-up period . Repeated attacks of BC further decreased survival probability . The responsive organisms were mainly enteric bacteria, including Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumanni, and Salmonella typhi . The sensitivity tests justified empirical therapy with ceftriaxone . The effectiveness of prophylactic trimethoprim-sulfamethoxazole or neomycin warrants further studies . BC was a highly prevalent postoperative complication in patients with BA, especially those with inadequate bile drainage . It significantly affected early mortality . Aggressive and complete treatment with empirical ceftriaxone was appropriate.

J Clin Microbiol, 2001 Sep, 39(9), 3247 - 53
Evaluation of the VITEK 2 system for the identification and susceptibility testing of three species of nonfermenting gram-negative rods frequently isolated from clinical samples; Joyanes P et al.; VITEK 2 is a new automatic system for the identification and susceptibility testing of the most clinically important bacteria . In the present study 198 clinical isolates, including Pseudomonas aeruginosa (n = 146), Acinetobacter baumannii (n = 25), and Stenotrophomonas maltophilia (n = 27) were evaluated . Reference susceptibility testing of cefepime, cefotaxime, ceftazidime, ciprofloxacin, gentamicin, imipenem, meropenem, piperacillin, tobramycin, levofloxacin (only for P . aeruginosa), co-trimoxazole (only for S . maltophilia), and ampicillin-sulbactam and tetracycline (only for A . baumannii) was performed by microdilution (NCCLS guidelines) . The VITEK 2 system correctly identified 91.6, 100, and 76% of P . aeruginosa, S . maltophilia, and A . baumannii isolates, respectively, within 3 h . The respective percentages of essential agreement (to within 1 twofold dilution) for P . aeruginosa and A . baumannii were 89.0 and 88.0% (cefepime), 91.1 and 100% (cefotaxime), 95.2 and 96.0% (ceftazidime), 98.6 and 100% (ciprofloxacin), 88.4 and 100% (gentamicin), 87.0 and 92.0% (imipenem), 85.0 and 88.0% (meropenem), 84.2 and 96.0% (piperacillin), and 97.3 and 80% (tobramycin) . The essential agreement for levofloxacin against P . aeruginosa was 86.3% . The percentages of essential agreement for ampicillin-sulbactam and tetracycline against A . baumannii were 88.0 and 100%, respectively . Very major errors for P . aeruginosa (resistant by the reference method, susceptible with the VITEK 2 system {resistant to susceptible}) were noted for cefepime (0.7%), cefotaxime (0.7%), gentamicin (0.7%), imipenem (1.4%), levofloxacin (2.7%), and piperacillin (2.7%) and, for one strain of A . baumannii, for imipenem . Major errors (susceptible to resistant) were noted only for P . aeruginosa and cefepime (2.0%), ceftazidime (0.7%), and piperacillin (3.4%) . Minor errors ranged from 0.0% for piperacillin to 22.6% for cefotaxime against P . aeruginosa and from 0.0% for piperacillin and ciprofloxacin to 20.0% for cefepime against A . baumannii . The VITEK 2 system provided co-trimoxazole MICs only for S . maltophilia; no very major or major errors were obtained for co-trimoxazole against this species . It is concluded that the VITEK 2 system allows the rapid identification of S . maltophilia and most P . aeruginosa and A . baumannii isolates . The VITEK 2 system can perform reliable susceptibility testing of many of the antimicrobial agents used against P . aeruginosa and A . baumannii . It would be desirable if new versions of the VITEK 2 software were able to determine MICs and the corresponding clinical categories of agents active against S . maltophilia.

Gastrointest Endosc, 2001 Sep, 54(3), 346 - 50
Expression of bacterial beta-glucuronidase in human bile: an in vitro study; Leung JW et al.; BACKGROUND: Bacterial beta-glucuronidase causes deconjugation of bilirubin diglucuronide resulting in the precipitation of calcium bilirubinate, which contributes to biliary sludge and stone formation . This process is attributed to enzyme activity produced by the aerobic enterobacteriaceae such as Escherichia coli and Klebsiella sp . The presence of Clostridium sp . was detected in 48 of 56 intrahepatic stones by using polymerase chain reaction techniques and cultured Clostridium perfringens from 14 of 18 unblocked biliary stents . Such bacteria are reported to produce beta-glucuronidase activity . The aim of this study was to determine the proportion of biliary bacteria isolated from pigment stones and stents that produce beta-glucuronidase and to compare the enzyme activity expressed by the different bacteria in human bile . METHODS: A total of 202 bacteria were isolated from blocked and unblocked biliary stents and pigment ductal stones recovered from patients . Of these, 61 bacteria expressed beta-glucuronidase activity in brain heart infusion broth . These 61 bacteria were subsequently grown in human bile under aerobic or anaerobic conditions to the early stationary phase and assayed for beta-glucuronidase activity by using rho-nitrophenyl beta-D glucuronide as substrate . Results were normalized and reported as units of enzyme activity per milligram protein of the bacteria . RESULTS: C . perfringens produced beta-glucuronidase enzyme activity that was 34-fold higher than that for E coli, Staphylococcus, Corynebacterium sp., Bacillus sp., Enterococcus sp., Acinetobacter sp., Streptococcus sp., and Klebsiella sp . CONCLUSION: C . perfringens with its higher enzyme activity is more important in the deconjugation of bilirubin diglucuronide than E coli and Klebsiella sp.

J Endotoxin Res, 2001, 7(2), 113 - 8
Structural and serological characterisation of the O-antigenic polysaccharide of the lipopolysaccharide from Acinetobacter strain 96 (DNA group 11); Vinogradov EV et al.; A polysaccharide containing D-Manp, L-Fucp (6-deoxygalactopyranose, fucose) and D-GlcpNAc was isolated by mild acid hydrolysis, followed by gel-permeation chromatography, from the lipopolysaccharide derived from Acinetobacter strain 96 (DNA group 11) . The structure of the O-antigen was determined by compositional analysis and NMR spectroscopy of the polysaccharide as: {carbohydrate structure see text} A monoclonal antibody obtained after immunization of mice with heat-killed bacteria of Acinetobacter strain 96 was shown to bind to the O-antigen and did not cross-react with any Acinetobacter O-antigen of known structure.

Infect Control Hosp Epidemiol, 2001 Jun, 22(6), 388 - 91
Infrequent isolation of multiresistant Acinetobacter baumannii from the staff tending a colonized patient with severe burns; Paavilainen T et al.; A patient with severe burns who was colonized by multiresistant Acinetobacter baumannii was cared for in contact isolation by staff intensively trained on hospital hygiene . Of the 1,907 postexposure cultures from the staff and 425 environmental samples, only 0.7% and 4%, respectively, yielded this microorganism . These data show that strict hygienic measures may limit staff colonization and contamination of the environment byA baumannii.

J S Afr Vet Assoc, 2001 Jun, 72(2), 97 - 8
Prevalence of microorganisms associated with udder infections in dairy goats on small-scale farms in Kenya; Ndegwa EN et al.; Six hundred and thirty clinically-normal milk samples from dairy goat flocks comprising a mixed population of German Alpine, Toggenburg, Saanen and Galla crosses were examined over a 3-month period to determine the prevalence of bacterial organisms . Bacteria were isolated in 28.7% of the milk samples (181/630) either singly (92.8%) or in combination (7.2%) . The most prevalent bacterial organisms were Staphylococcus spp . (60.3%), followed by Micrococcus spp . (17.7%), Acinetobacter spp . (5%), Actinomyces spp . (5%) and Streptococcus spp . (1.1%) . The Staphylococcus spp . were mainly coagulase negative (64.3%) . Coagulase-negative staphylococci and coagulase-positive staphylococci accounted for 37.5% and 22.7% respectively of the total bacteria isolated . The isolation of bacteria, some of which are important in clinical and subclinical mastitis, in apparently normal caprine milk, indicates that particular attention should be given to the management of these dairy goat flocks in order to avoid the development of cases of clinical mastitis.

Biochem Biophys Res Commun, 2001 Aug 24, 286(3), 652 - 8
Molecular characterization of the 56-kDa CYP153 from Acinetobacter sp . EB104; Maier T et al.; CYP153 a cytochrome P450 from Acinetobacter sp . EB104 catalyzes the hydroxylation of unsubstituted n-alkanes . We have decided to use the CYP153 system as a model for mechanistic studies on regioselective n-alkane oxidation and the interaction of hydrophobic substrates with soluble enzymes . Here the molecular cloning of the CYP153 gene is reported . Single specific primer PCR was applied to yield the whole gene sequence via chromosomal walks . CYP153 consists of 497 amino acids (M(r) = 56 kDa) and thus represents an unusually long bacterial P450, containing all P450 typical structural elements . It constitutes the new P450 family CYP153 . The prolonged N-terminus of about 90 amino acids does not contain a so far known membrane-anchoring sequence but a 28-amino acid long amphipathic helix . The relevance of the remarkably long N-terminus and of other sequence motives like the hydrophobic F-G loop is discussed with respect to substrate binding and recognition .

Braz J Infect Dis, 2001 Jun, 5(3), 103 - 10
Multiple organ failure in septic patients; Bilevicius E et al.; Multiple organ failure (MOF) is the main cause of death in ICUs, especially affecting septic patients . It is strongly related to number of systems with failure, type of system involved, risk factors such as age, previous chronic diseases, delayed or inadequate resuscitation, persistent infection, immune suppression, and others . The prognoses is worse for patients rather than in elective or emergency surgical patients . The objective of this article is to provide data from our university teaching hospital ICU related to the incidence of septic patients, the distribution of MOF, and distribution of failure among each of the organs . The mortality rate, relationship between mortality and age, and mortality and types of organs affected were evaluated . The main bacterial causes of sepsis were also identified . A retrospective evaluation was done of 249 patients admitted to the ICU in a 4 month period during 1999 . Fifty four patients had sepsis diagnosed by ACCS/SCCM criteria . There were 37 men and 17 women; 24 medical and 30 post-surgical patients (9 after elective surgery and 21 emergency patients) . APACHE II score was calculated on admission and MOF, measured for the first five days, was diagnosed using Marshall and Meakins criteria . The statistical method used was non-parametric Mann-Whitney test, p<0.05 was considered significant . The incidence of sepsis was recorded in 54/249 patients (22%) . Thirty of these 54 patients (56%) died . Death occurred in 2 of 11 patients with one organ failure (18%), in 14/27 with 2 or 3 organ failures (52%), and 14/16 with 4 or more organ failures (88%) . None of the three patients 15 to 20 years old died, 17/32 (55%) patients age 21-60 years, and >61 years 13/19 (68%), died . There were 23 patients with positive bacterial culture . The most frequent bacteria found were: Pseudomonas aeruginosa (5), multiresistant Acinetobacter baumanii (3), Staphylococcus epidermidis (3), Enterobacter aerogenes (3), Klebsiella pneumoniae (2) and multiresistant Staphylococcus aureus (2) . The mean value +/- SD of APACHE II (mortality risk) for survivors was 21 +/- 18 and for non-survivors 42 +/- 26 (p<0.001) . We conclude that MOF due to sepsis in an ICU is frequent, with high mortality related to the number of failing organs, age and high APACHE II.

Biotechnol Bioeng, 2001 Sep, 76(2), 108 - 14
Metabolic engineering of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) composition in recombinant Salmonella enterica serovar typhimurium; Aldor I et al.; A recombinant strain of Salmonella enterica serovar Typhimurium (mutant in propionate-activation activity) was metabolically engineered to control the composition of poly(3-hydroxybutyrate-co-3-hydroxy- valerate) (PHBV), a polyhydroxyalkanoate copolymer with commercially desirable properties . A gene (prpE) encoding propionyl-CoA synthetase was placed under the control of the IPTG-inducible taclacUV5 promoter (P(taclacUV5)) while the polyhydroxyalkanoate synthesis operon (phaBCA) from Acinetobacter sp . RA3849 was coexpressed under the control of the arabinose-inducible araBAD promoter (P(BAD)) . S . enterica, harboring both constructs, was grown in medium containing a fixed substrate concentration and the composition of the copolymer was varied between 2 mol% and 25 mol% 3-hydroxyvalerate by controlling the IPTG level in the medium . This "dial-a-composition" system should find application in cases where the substrate concentration of a feedstream for PHBV bioplastic production is not adjustable .

Diagn Microbiol Infect Dis, 2001 Jul, 40(3), 117 - 20
Interactions of colistin and rifampin on multidrug-resistant Acinetobacter baumannii; Giamarellos-Bourboulis EJ et al.; The increased incidence of nosocomial infections by multidrug-resistant Acinetobacter spp creates demand on the application of some combinations of older antimicrobials on that species . The in vitro activities of colistin and of rifampin and of their interaction were tested on 39 nosocomial isolates of Acinetobacter baumannii . All isolates were resistant to ampicillin/sulbactam, to 3(rd) and 4(th) generation cephalosporins, to amikacin and to ciprofloxacin . MICs were determined by a microdilution technique and interactive studies between 1x or 4x MIC of colistin and rifampin were performed by the time-kill assay . Rifampin was applied at a concentration of 2 microg/mL which is equal to its mean serum level . All isolates were inhibited by colistin and only 15.2% by rifampin . Synergy between 1x MIC of colistin and rifampin was detected in 15.4% of isolates at 6 h of growth and in 51.3% of isolates at 24 h of growth . Synergy between 4x MIC of colistin and rifampin was detected in 15.4% of isolates at 6 h of growth and in 66.7% of isolates at 24 h of growth . It is concluded that colistin is highly active on multidrug-resistant Acinetobacter spp and its activity on A.baumannii is increased in the presence of rifampin, so that their administration might be proposed for nosocomial infections by these isolates.

Ethiop Med J, 2001 Apr, 39(2), 97 - 104
Prevalence and antibiotic susceptibility pattern of bacterial isolates from blood culture in Tikur Anbassa Hospital, Addis Ababa, Ethiopia; Asrat D et al.; Between Mid-1996 and Mid-1998, 238 bacteria strains isolated from blood culture of adult patients of Tikur Anbassa Hospital, Addis Ababa, Ethiopia, were retrospectively analyzed for their frequency of isolation and antibiotic susceptibility pattern . Coagulase negative Staphylococcus aureus (CNS) were isolated with the highest frequency 103 (43.3%), followed by Staphylococcus aureus 34(14.3%), Klebsiella spp . 23(9.7%), E . Coli 19(8.1%), Pseudomonas spp . 16(6.7%), Acinetobacter spp . 12(5%), Salmonella spp . 9(3.8%) and miscellaneous group 22(9.2%) . The gram positive bacteria constituted 149(62.6%) of the total blood isolates . It is suggested that a proportion of both the gram positive and gram negative isolated represent contaminants at blood sampling . Rates of susceptibility for gram positive range from 12% to 76%, and for gram negatives range from 8% to 46% . In general, rates of susceptibilities to all antibiotics tested for gram negatives were very low as compared to gram positives . Among the gram positives, more than half of the isolates were sensitive to amoxicillin + clavulanic acid, ampicillin, carbenicillin, cephalothin, chloramphenicol, erythromycin and methicillin . Gram negative bacteria showed a high rate of resistance to many of the commonly prescribed antimicrobial drugs: amoxicillin + clavulanic acid (65%), ampicillin (87.5%), amoxicillin (91.7%), carbenicillin (75%), cephalothin (73.6%), chloramphenicol (65%), gentamicin (55.6%), kanamycin (54%), trimethoprim-sulphamethoxazole (64%) and tetracycline (61%) . If generally considered, only gentamicin and kanamycin were relatively effective against gram negatives . Over 85% Salmonella spp were sensitive to chloramphenicol and trimethoprim-sulphamethoxazole . Compared to previous studies done in the same hospital, there is a higher rate of antibiotic resistance for most types of blood culture isolates particularly for gram negatives . The rational use of drugs should be practiced in order to minimize the spread of drug resistant bacteria.

Ethiop Med J, 2001 Apr, 39(2), 113 - 21
Otitis media seen in Yekatit 12 Hospital; Tessema G; Two thousand three hundred and thirty four selected patients with ear problem were seen in one of the ENT out patients department of Yekatit 12 Hospital from September 1994 to August 1996 were prospectively studied . Most of the patients came from Addis Ababa . Major clinical presentations were ear pain, purulent ear discharge, uni or bilateral decreased hearing ability . Patients were carefully evaluated by physical examination, otoscopy examination of the ear, schuilers view of the mastoid bone, audiometry findings and pus culture results . Diagnosis of these patients revealed that 1,630 (69.8%) had otitis while the rest 704 (30.16%) had other ear problems like ear wax, tinnitus and otitis external . One hundred two hundred thirty two patients (52.8%) had chronic otitis media with purulent discharge and decreased hearing ability, while 245 patients (10.5%) had chronic otitis media with out purulent discharge but with decreased hearing ability . Ninety six patients (4.1%) had acute otitis media and 57 patients (2.4%) had chronic seromucinous otitis media with decreased hearing ability . The micro-organisms identified include klebsiella spp . (28.97%), E . coli (10.7%), Citrobacter (3.6%), Acinetobacter (4.7%), S . aureus (3.57%), P . Valgaris (4.3%), S . Epidermidis (4.54%) and Dephtheroids (7.3%) . Eighty nine patients with acute otitis media were completely cured and regained their hearing ability, the rest did not regain their hearing ability despite treatment . A combination of antibiotics and surgical treatment is recognized as the most effective intervention in this situation . The management of the chronic draining ear are: 1) . To achieve a clean healed dry ear, 2) to obtain an air-containing middle ear space, 3) to rehabilitate hearing . The prevention of deafness and treatment of chronic draining ear disease especially in children is surgery which is not yet fully practiced in our centers.

Appl Microbiol Biotechnol, 2001 Jul, 56(1-2), 243 - 8
Antimicrobial activity of argon fluoride (ArF) excimer laser on gram-negative bacteria; Charvalos E et al.; The objective of this study was to evaluate the antibacterial activity of argon fluoride (ArF) excimer laser radiation on clinically important strains of gram-negative bacteria . The antibacterial activity of ArF excimer laser radiation was evaluated on two Acinetobacter baumannii, one Enterobacter cloacae, three Escherichia coli, two Helicobacter pylori, one Klebsiella pneumoniae and two Pseudomonas aeruginosa strains . The strains were isolated from clinical specimens and typed by the usual biochemical procedures . Square agar plates of 12 x 12 cm were divided into rectangular (2 x 3 cm) regions and spread with 0.5x 10(4) colony forming units (CFU)/ml of bacterial suspension . The excess liquid was removed and the plates were allowed to dry for 30 min . A total of 96 rectangular (2x3 cm) regions were used for each strain, in order to test an equal number of laser parameters . Each rectangular region was irradiated with different laser parameters, using a 193 nm ArF excimer laser, linked with a simple Galilean afocal system and a rectangular diaphragm of the same dimensions as the original laser beam cross-section, at a distance of 10 cm from the irradiated surface . This system was used in order to keep the laser pulse energy under 80 mJ and to cut-out the non-transverse electromagnetic mode branches of the laser beam . We then studied the bacterial survival ratio versus the number of laser pulses, the repetition frequency and the total laser beam fluence . Our results showed that the total laser beam fluence was the most important parameter to consider in evaluating the bactericidal effect of ArF excimer laser radiation . A critical value of the total fluence was determined for each strain, such that, for laser beam fluences greater than this critical value, no colonies appeared to survive while, for laser fluences less than this critical value, the survival ratio did not exceed 2 x 10(7) CFU (2 x 10(-5)%) . These critical values were found to vary between 8 J/cm2 and 16 J/cm2 for the bacterial species studied . Under these conditions, ArF laser irradiation is promising for the sterilisation of hard surfaces and for in situ application.

Rev Esp Quimioter, 2000 Dec, 13(4), 405 - 7
{Activity of imipenem and meropenem against strains of Acinetobacter baumannii isolated from various Chilean hospitals}; Bello H et al.; The activity of two carbapenem compounds, imipenem and meropenem, against 447 strains of Acinetobacter baumannii isolated between 1990 and 1998 in different Chilean hospitals was determined . MIC ranges, MIC(50) and MIC(90), were determined by an agar dilution method . Similar antibacterial activities were observed for both antibacterials; however, a slight increase in the MIC(50) of imipenem and meropenem, and in the MIC(90) of meropenem was found among strains isolated from 1997-1998 . Although A . baumannii remains susceptible to these antibiotics, the MIC(50) and MIC(90) have increased in recent years.

Rev Esp Quimioter, 2000 Dec, 13(4), 401 - 4
{Antibacterial activity of aminoglycosides against nosocomial strains of Acinetobacter baumannii isolated between 1990 and 1999}; Gonzalez G et al.; The antibacterial activity of selected aminoglycosides against 487 nosocomial strains of Acinetobacter baumannii isolated from Chilean hospitals between 1990 and 1998 was investigated . Plasmid profiles were determined for some resistant isolates . A high frequency of resistant strains was found for all aminoglycosides assayed, with values ranging from 47% for amikacin (1990-1992) to 88% for gentamicin (1993-1994) . The cure of a plasmid greater than 30 kb was associated with the loss of amikacin, kanamycin and neomycin resistance in some isolates . This result suggests that plasmid may harbor the genes encoding for the combination of aminoglycoside-modifying enzymes AAC(6')I+APH(3') . Gentamicin resistance was not lost among cured strains, suggesting it may be encoded by genes located on the bacterial chromosome or transposons inserted on the chromosome.

Rev Esp Quimioter, 2000 Dec, 13(4), 394 - 400
{Evolution of antimicrobial susceptibility of Acinetobacter baumannii clinical isolates}; Lopez-Hernandez S et al.; Acinetobacter baumannii is a microorganism frequently implicated in colonization and infection in hospitalized patients . An increase of resistance has been observed in recent years making these infections difficult to treat . The in vitro activity of 24 antibiotics, 15 betalactam agents and nine nonbetalactams, was studied in 156 A . baumannii clinical isolates . The strains were collected from different clinical samples obtained from inpatients (92%) and 8% were from outpatients . Evolution of susceptibility from January 1995 to December 1997 was studied . MIC of the following antibiotics was determined by the agar dilution method: ampicillin, ticarcillin, piperacillin, ampicillin-sulbactam, amoxicillin- clavulanic acid, ticarcillin-clavulanic acid, piperacillin-tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, meropenem, clavulanic acid, sulbactam, tazobactam, amikacin, gentamicin, tobramycin, ofloxacin, doxycycline, fosfomycin, rifampin, azithromycin and colistin . Low antimicrobial susceptibility was observed in most A . baumannii strains . Colistin, imipenem, meropenem and ampicillin-sulbactam showed the greatest susceptibility (100, 88.4, 88.4 and 84.6%, respectively) . A . baumannii strains from inpatients showed a lower antimicrobial susceptibility than strains from outpatients, who showed a high percentage of susceptibility to most antibiotics . Rifampin and azithromycin showed certain in vitro activity against the most susceptible A . baumannii strains . A progressive decrease in susceptibility to most antibiotics was observed during the period studied . Carbapenem-resistant A . baumannii emerged in 1996 and increased in 1997.

J Microsc, 2001 Aug, 203(Pt 2), 227 - 30
Rapid contrasting of ultrathin sections using microwave irradiation with heat dissipation; Hernandez-Chavarria F et al.; The use of microwave irradiation (MWI) to accelerate fixation, dehydration and contrasting (staining) for electron microscopy has been applied to the development of rapid methods to process biological samples in electron microscopy . A simple explanation is that the reduced time in those procedures is due to heating . In this paper we propose a contrasting method for thin sections that avoids the thermal effects of MWI . Grids with thin sections of mouse kidney, the dinoflagellate Alexandrium monilatum, spermatophores of the fly Archicepsis diversiformis, the bacteria Acinetobacter calcoaceticum and Enterobacter cloacae were placed into Beem capsules and stained with uranyl acetate and lead citrate, while immersed in an ice-water bath, and irradiated for periods ranging from 30 s to 2 min . After each contrasting procedure, the Beem capsule was filled with distilled water to wash the grids under MWI with the same irradiation time as used to contrast . Good results were obtained on irradiating for 1 min and the temperature of the Beem capsule was maintained around 5 degrees C.

J Pak Med Assoc, 2001 Jun, 51(6), 213 - 5
Blood stream infections in a medical intensive care unit: spectrum and antibiotic susceptibility pattern; Mahmood A; OBJECTIVE: To determine the type and sensitivity pattern of causative organisms of septicaemia in intensive care unit, to prepare a guideline for empirical antibiotic therapy . SETTING: Department of pathology and adult medical intensive care unit, PNS SHIFA (Naval Hospital), Karachi . METHODS: The study was conducted from January 1997 to June 1999 . Blood specimens for culture were drawn from patients who developed symptoms/signs of bacteraemia/septicaemia 48 hours or more after admission in medical ICU . The specimens were inoculated into Brain Heart Infusion broth . Subcultures were done on days 1,2,3,5,7 and 10 . The isolates were identified by standard biochemical tests . Antibiotic susceptibility pattern of the isolates was studied by Modified Kirby Baur method . RESULTS: Eighty-six aerobic organisms were isolated . They included Staphylococcus aureus(n = 34), Pseudomonas aeruginosa (n = 13), Escherichia coli and Enterobacter spp(n = 9 each), Klebsiella pneumoniae(n = 8), Acinetobacter spp and Serratia spp(n = 5 each), Citrobacter diversus(n = 2) and Proteus vulgaris(n = 1) . On antibiotic susceptibility testing, 48.18% Staphylococcus aureus isolates were methicillin resistant . Susceptibility to other common drugs was also quite low while 100% of these were susceptible to vancomycin and amikacin . In case of gram negative rods more than 80% were resistant to ampicillin and cotrimoxazole . Susceptibility to gentamicin was as low as 25% for Klebsiella pneumoniae to 44.4% in case of Escherichia coli . Susceptibility to the third generation cephalosporins and the quinolone tested (ciprofloxacin) varied between 50-75% . All these isolates except Pseudomonas aeruginosa were susceptible to imipenem and amikacin . CONCLUSION: In view of the isolation of antibiotic resistant organisms, vancomycin in combination with amikacin or imipenem are the drugs of choice for empirically treating blood stream infections in ICU . Infection control procedures and antibiotic control policies can help to tackle this problem.

Perit Dial Int, 2001 May-Jun, 21(3), 296 - 301
Polymicrobial outbreak of intermittent peritoneal dialysis peritonitis during external wall renovation at a dialysis center; Cheng VC et al.; OBJECTIVE: To investigate an outbreak of peritonitis in intermittent peritoneal dialysis (IPD) patients . DESIGN: An outbreak investigation was performed to identify the etiology of the polymicrobial outbreak, and a retrospective case-control study was conducted to assess the risk factors for development of peritonitis . SETTING: Renal dialysis center . PATIENTS: Ten episodes of peritonitis occurred in 8 of 61 patients over a 6-month period in which 669 IPD procedures were analyzed . INTERVENTIONS: Field visit to renal dialysis center to examine the entire IPD procedure, inspect the hospital environment, and perform air bacterial count . MAIN OUTCOME MEASURES: The environmental factors and risk factors contributing to the polymicrobial peritonitis outbreak in IPD patients . The incidence of IPD peritonitis was determined before and after interventions . RESULTS: The causative organisms included Acinetobacter baumanii (6), Stenotrophomonas maltophilia (2), Pseudomonas aeruginosa (1), Candida albicans (1), C . tropicalis (1), Enterococcus (3), and Enterobacteriaceae (2) . Four episodes of peritonitis involved infection by more than one organism . Air sampling of the environment detected a median of 110 colony forming units of bacteria per cubic meter of air, 10% of which were found to be Acinetobacter baumanii . The source of this polymicrobial outbreak was attributed to the bamboo scaffolding structure covering the external wall of the hospital during renovation . A retrospective case-control study indicated that the absence of the flush-before-fill step was a risk factor for development of peritonitis . CONCLUSION: In addition to invasive aspergillosis in transplant or oncology patients, Acinetobacter peritonitis in dialysis patients should be considered another microbial cause of outbreak associated with hospital renovation.

J Appl Microbiol, 2001 Aug, 91(2), 290 - 8
Studies on bioemulsifier production by Acinetobacter strains isolated from healthy human skin; Patil JR et al.; AIMS: In recent years, interest has been growing in the search for novel bioemulsifiers . Many bacterial genera including Acinetobacter have been reported to produce bioemulsifiers . The present study aims to screen Acinetobacter isolates from healthy human skin for bioemulsifier production . Methods and Results: Acinetobacter junii SC14 produced maximum bioemulsifier in the presence of almond oil during stationary growth phase at 37 degrees C and pH 7.2 . Partially purified, nondialysable bioemulsifier from SC14 was a proteoglycan . The protein and polysaccharide fractions resulted in 95.2% reconstitution of the emulsification activity . The role of esterase in the release of cell-bound emulsifier and the contribution of capsular polysaccharide to the emulsification activity were observed . CONCLUSION: Acinetobacter strains from human skin exhibited better emulsification activity than that by burn wound or soil isolates, owing to the inherent differences in chemical microenvironment of their habitats . SIGNIFICANCE AND IMPACT OF THE STUDY: Investigation of skin commensals, especially acinetobacters, would lead to the discovery of novel bioemulsifiers with interesting properties . Attempts of screening and strain improvement directed towards skin commensals will open up new avenues for strains producing bioemulsifier on a commercial scale.

J Appl Microbiol, 2001 Aug, 91(2), 237 - 47
Modelling bacterial spoilage in cold-filled ready to drink beverages by Acinetobacter calcoaceticus and Gluconobacter oxydans; Battey AS et al.; AIMS: Mathematical models were created which predict the growth of spoilage bacteria in response to various preservation systems . METHODS AND RESULTS: A Box-Behnken design included five variables: pH (2.8, 3.3, 3.8), titratable acidity (0.20%, 0.40%, 0.60%), sugar (8.0, 12.0, 16.0 * Brix), sodium benzoate concentration (100, 225, 350 ppm), and potassium sorbate concentration (100, 225, 350 ppm) . Duplicate samples were inoculated with a bacterial cocktail (100 microl 50 ml(-1)) consisting of equal proportions of Acinetobacter calcoaceticus and Gluconobacter oxydans (5 x 10(5) cfu ml(-1) each) . Bacteria from the inoculated samples were enumerated on malt extract agar at zero, one, two, four, six, and eight weeks . CONCLUSION: The pH, titratable acidity, sugar content, sodium benzoate, and potassium sorbate levels were all significant factors in predicting the growth of spoilage bacteria . SIGNIFICANCE AND IMPACT OF THE STUDY: This beverage spoilage model can be used to predict microbial stability in new beverage product development and potentially reduce the cost and time involved in microbial challenge testing.

Arthritis Rheum, 2001 Jul, 44(7), 1689 - 97
Chromosomal DNA from a variety of bacterial species is present in synovial tissue from patients with various forms of arthritis; Gerard HC et al.; OBJECTIVE: We and others have reported the presence of Chlamydia and other bacterial species in joint specimens from patients with reactive arthritis (ReA) . The present study was conducted to investigate whether bacteria other than those specified by diagnostic criteria for ReA could be identified in synovial fluid (SF) or tissue from patients with various arthritides, and whether the presence of such organisms corresponds to particular clinical characteristics in any patient set or subset . METHODS: DNA in synovial biopsy samples and SF obtained from 237 patients with various arthritides, including ReA, rheumatoid arthritis, and undifferentiated oligoarthritis, was assayed by polymerase chain reaction (PCR) using "panbacterial" primers; we chose only samples known to be PCR negative for Chlamydia, Borrelia, and Mycoplasma species . PCR products were cloned, and cloned amplicons from each sample were sequenced; DNA sequences were compared against all others in GenBank for identification of bacterial species involved . RESULTS: Ten percent of patient samples were PCR positive in panbacterial screening assays . Bacterial species identified belonged to the genera Neisseria, Acinetobacter, Moraxella, Salmonella, Pseudomonas, and others . Thirty-five percent of PCR-positive patients showed the presence of DNA from more than a single bacterial species in synovium; overall, however, we could identify no clear relationship between specific single or multiple bacterial species in the synovium and any general clinical characteristics of any individual or group of patients . CONCLUSION: This analysis provides the first systematic attempt to relate bacterial nucleic acids in the synovium to clinical characteristics, joint findings, and outcomes . Many patients with arthritis have bacterial DNA in the joint, and, in some cases, DNA from more than a single species is present . However, except for 1 case of a control patient with staphylococcal septic arthritis, it is not clear from the present study whether the synovial presence of such organisms is related to disease pathogenesis or evolution in any or all cases.

Biochem J, 2001 Aug 1, 357(Pt 3), 893 - 8
Ca(2+) stabilizes the semiquinone radical of pyrroloquinoline quinone; Sato A et al.; Spectroelectrochemical studies were performed on the interaction between Ca(2+) and pyrroloquinoline quinone (PQQ) in soluble glucose dehydrogenase (sGDH) and in the free state by applying a mediated continuous-flow column electrolytic spectroelectrochemical technique . The enzyme forms used were holo-sGDH (the holo-form of sGDH from Acinetobacter calcoaceticus) and an incompletely reconstituted form of this, holo-X, in which the PQQ-activating Ca(2+) is lacking . The spectroelectrochemical and ESR data clearly demonstrated the generation of the semiquinone radical of PQQ in holo-sGDH and in the free state in the presence of Ca(2+) . In contrast, in the absence of Ca(2+) no semiquinone was observed, either for PQQ in the free state (at pH 7.0) or in the enzyme (holo-X) . Incorporation of Ca(2+) into the active site of holo-X, yielding holo-sGDH, caused not only stabilization of the semiquinone form of PQQ but also a negative shift (of 26.5 mV) of the two-electron redox potential, indicating that the effect of Ca(2+) is stronger on the oxidized than on the reduced PQQ . Combining these data with the observations on the kinetic and chemical mechanisms, it was concluded that the strong stimulating effect of Ca(2+) on the activity of sGDH can be attributed to facilitation of certain kinetic steps, and not to improvement of the thermodynamics of substrate oxidation . The consequences of this conclusion are discussed for the oxidative as well as for the reductive part of the reaction of sGDH.

J Microbiol Immunol Infect, 2001 Jun, 34(2), 131 - 7
Efficacy of cefepime versus ceftazidime in the treatment of adult pneumonia; Lin JC et al.; Effective empiric treatment of pneumonia requires antibiotic coverage against gram-negative and gram-positive pathogens, including drug-resistant isolates . This study evaluated the efficacy of cefepime treatment in 20 patients with community-acquired pneumonia (CAP) and 21 patients with hospital-acquired pneumonia (HAP), and ceftazidime treatment in 20 patients with HAP . The mean age of patients was over 70 years . More than half of the patients had multiple lobe involvement . There was no significant difference in the severity of illness according to the acute physiology, age, chronic health evaluation (APACHE) III score between the HAP-cefepime and HAP-ceftazidime group . The most common bacteria isolated from sputum of patients with CAP were Streptococcus pneumoniae (n = 7), Klebsiella pneumoniae (n = 4), and Pseudomonas aeruginosa (n = 2) . In patients with HAP, P . aeruginosa (n = 13), Acinetobacter baumannii (n = 11), Serratia marcescens (n = 6), K . pneumoniae (n = 5), Stenotrophomonas maltophilia (n = 5), Enterobacter cloacae (n = 3), Citrobacter spp . (n = 2), and Escherichia coli (n = 2) were isolated . The cure rates were 95%, 76%, and 60% in the CAP-cefepime group, the HAP-cefepime group, and the HAP-ceftazidime group, respectively . The increased rates of antimicrobial resistance commonly found among isolates causing CAP and HAP indicate that extended-spectrum antimicrobial agents, such as cefepime, would be more appropriate therapeutic agents.

Ann Acad Med Singapore, 2001 May, 30(3), 234 - 8
The role of early tracheostomy in critically ill neurosurgical patients; Teoh WH et al.; OBJECTIVE: To determine the value of early tracheostomy (within 7 days) in ventilated neurosurgical patients . METHODS: Retrospective review of intubated patients in the neurosurgical intensive care unit (NICU) who underwent elective open tracheostomies for prolonged ventilation . RESULTS: Thirty patients over a 2-year period were analysed . There were 19 males and 11 females, mean age 53.9 +/- 18.1 years (range 14 to 89), and mean Glasgow Coma Scale (GCS) score on admission 7.1 +/- 3.8 (range 3 to 15) . The underlying disease aetiology was cerebrovascular disease in 53% of patients, head trauma in 33% and tumour or infection in 13% . Tracheostomy was performed after a mean period of 8.5 +/- 3.5 days (range 2 to 18), with patients requiring ventilation for a mean duration of 13.5 +/- 6.3 days (range 3 to 31) . Complications were minimal; 1 wound infection (3.3%) and 4 tube obstructions (13.3%) . Patients who underwent elective early tracheostomy (Group 1 = within 7 days) had poorer GCS on admission (6.3 +/- 2.9 versus 7.7 +/- 4.3 in Group 2, P = 0.271) . Tracheostomy was performed after a mean of 5.3 +/- 1.7 days in Group I vs . 10.6 +/- 2.7 days in Group 2 . Group 1 patients had faster recovery from nosocomial pneumonia (12.3 +/- 6.2 versus 17.9 +/- 12.5 days, P = 0.168), shorter duration of ventilation (9.8 +/- 5.9 versus 16.0 +/- 5.4 days, P = 0.007), and reduced incidence of multibacterial tracheobronchial colonisation (42% versus 72%, P = 0.098) . The most prevalent organisms were Acinetobacter baumanii (43.3%), Pseudomonas (40%), methicillin-resistant Staphylococcus aureus (MRSA) (33%), Klebsiella (30%) and Staphylococcus aureus (26.7%) . CONCLUSION: Early tracheostomy in selected neurosurgical patients with poor GCS scores was associated with reduced incidence of tracheobronchial colonisation by multiple pathogens, improvement in chest infections, and rapid weaning from ventilatory support.

J Infect Chemother, 2001 Jun, 7(2), 117 - 20
Surveillance of bacterial resistance among isolates in Shanghai in 1999; Wang F et al.; We report here surveillance data on the bacterial resistance of clinical isolates from 11 Shanghai hospitals in 1999, for guidance in the clinical use of antibacterial agents . Of the 14,855 strains collected, 5130 (34.5%) were Gram-positive cocci and 9725 (65.5%) were Gram-negative bacilli . The most common organisms in descending order of frequency, were: Escherichia coli (16%), coagulase-negative staphylococci (CNS; 14.3%), Klebsiella spp . (12.3%), Staphylococcus aureus (11.5%), Pseudomonas aeruginosa (9.2%), Acinetobacter spp . (8.1%), and Enterococcus spp . (6.6%) . Methicillin-resistant strains accounted for 64% and 77% of S . aureus and CNS, respectively . The methicillin-sensitive strains were susceptible to most agents tested, while most methicillin-resistant strains were resistant to these agents . No vancomycin-resistant staphylococci were identified . Vancomycin-resistant strains accounted for 3.6% of Enterococcus fecalis and 1.7% of E . fecium . E . coli strains resistant to piperacillin, gentamicin, and fluoroquinolones accounted for 50% or more of the strains, and the resistance rates of Klebsiella spp., Enterobacter spp., Citrobacter spp., and Acinetobacter spp . to third-generation cephalosporins had increased markedly compared with rates in recent years . Resistance rates of P . aeruginosa to ceftazidime and imipenem (27% and 20%, respectively) had also increased compared with rates in recent years . A national strategy on the limited and prudent use of antibiotics is urgently needed.

Carbohydr Res, 2001 Jul 19, 333(4), 339 - 42
A very efficient method to cleave Lipid A and saccharide components in bacterial lipopolysaccharides; Manzo E et al.; A novel mild procedure for the selective cleavage of ketosidic linkages is developed using ceric ammonium nitrate (CAN) in anhydrous N,N-dimethylformamide . Its application to lipopolysaccharides (LPS) is very significant because in the so far investigated LPS, the connection between the Lipid A region and the oligo(poly)saccharide part is always a keto-sugar . This procedure has been tested on LPS of Escherichia coli which contains Kdo as a linker between Lipid A and OPS and on Acinetobacter haemoliticus which contains D-glycero-D-talo-2-octulopyranosonic acid (Ko) as a linker and it performed efficiently in both cases.

J Chemother, 2001 Jun, 13(3), 260 - 4
Antibiotic resistance among Gram-negative non-fermentative bacteria at a teaching hospital in Saudi Arabia; Eltahawy AT et al.; The incidence and antimicrobial resistance of Gram-negative non-fermentative bacteria isolated over 1 year at King Abdulaziz University Hospital, Jeddah, Saudi Arabia were investigated . A total of 499 of these microorganisms were collected and account for 16% of all Gram-negative bacteria isolated . The most common species were Pseudomonas aeruginosa 291 (56%), Acinetobacter baumannii 170 (34%), and Stenotrophomonas maltophilia 35 (7%) . 168 (34%) of these microorganisms were isolated from Intensive Care Unit (ICU), 147 (30%) from General Medicine, and 24 (25%) from Surgery wards . ICU was the main site of isolation of P . aeruginosa and S . maltophilia, while A . baumannii was more frequently isolated from medicine and surgery units . The vast majority of the isolates were resistant to many antibiotics tested . The antimicrobial resistance patterns of P . aeruginosa showed lowest resistance to imipenem (13%), amikacin (17%), and ciprofloxacin (18%) . Imipenem was also the most active antimicrobial agent against A . baumannii (15%) resistance . S . maltophilia exhibited multi-drug resistance, and was susceptible only to sulfonamide (6%).

J Korean Med Sci, 2001 Jun, 16(3), 262 - 70
Antimicrobial resistance surveillance of bacteria in 1999 in Korea with a special reference to resistance of enterococci to vancomycin and gram-negative bacilli to third generation cephalosporin, imipenem, and fluoroquinolone; Lee K et al.; The trend of antimicrobial resistance of bacteria isolated from patients in 30 Korean hospitals in 1999 was analyzed with a particular attention to cefotaxime- or fluoroquinolone-resistant gram-negative bacilli, imipenem-resistant Pseudomonas aeruginosa, and vancomycin-resistant enterococci . Adequacy of susceptibility testing, and any change in the frequencies of isolated species were also analyzed . The results showed that only 20% and 30% of hospitals tested the piperacillin-tazobactam and cefoxitin susceptibility of Enterobacteriaceae, respectively, only 24% of hospitals the piperacillin-tazobactam susceptibility of P . aeruginosa, and 17% of hospitals the fusidic acid susceptibility of staphylococci . Among the isolates 26.3% were glucose-nonfermenting gram-negative bacilli, and 34.7% of Enterococcus were Enterococcus faecium . Slight decline of cefotaxime-resistance rate to 20% was noted in Klebsiella pneumoniae, while fluoroquinolone-resistance rate was 68% in Acinetobacter baumannii . The ceftazidime- and imipenem-resistance rates were 17% and 18%, respectively in P . aeruginosa . The vancomycin-resistance rate of E . faecium rose significantly to 15.1%, but the rates varied significantly depending on hospitals suggesting presence of different degree of selective pressure or nosocomial spread . In conclusion, the prevalence of imipenem-resistant P . aeruginosa and the increase of vancomycin-resistant E . faecium were the particularly worrisome phenomena observed in this study.

Neurol India, 2001 Jun, 49(2), 134 - 7
Nosocomial infections due to Acinetobacter baumannii in a neurosurgery ICU; Gulati S et al.; Invasive infections caused by Acinetobacter baumannii in a post-operative neurosurgery ICU were studied . Sixty one patients admitted during a span of 11 months were culture positive for acinetobacter species from blood and/or CSF samples . They were followed up prospectively for evidence of infection and clinical outcome . 40 cases had clinical evidence of infection due to acinetobacter species while in 21 patients, the isolation of the organism was considered a contaminant . Acinetobacter baumannii was the most common organism associated with invasive infections . Respiratory tract was found to be the most common primary source of infection in patients with bacteraemia or meningitis . The age, sex and pre-operative hospital stay were not significantly different in the two groups (p>0.05), while post-operative hospital stay and mortality was significantly higher in patients with invasive infection (p<0.05) . Acinetobacter baumannii was isolated from multiple sites (p<0.05) and repeatedly from the same site (p<0.001) in a significantly higher number of patients with invasive infections . Mortality was high in the patients infected with Acinetobacter baumannii . Even amongst the infected group, the patient shaving meningitis showed a higher mortality as compared to the patients having bacteraemia.

Clin Experiment Ophthalmol, 2001 Jun, 29(3), 153 - 6
Random amplified polymorphic DNA analysis of Acinetobacter species isolated from worn contact lenses; Corrigan KM et al.; The purpose of this study was to explore the genotypes of Acinetobacter species and to compare the genotypes and phenotypes of the Acinetobacter isolated from contact lens wearers . Nineteen strains were used in the study, 13 were isolated from patients experiencing an adverse response event, and six strains were isolated from asymptomatic contact lens wearers . Random amplified polymorphic DNA and phenotypic analyses were carried out using commercially available kits . Random amplified polymorphic DNA analysis showed a higher discrimination power compared with the phenotypic analysis . The test strains were loosely clustered into six genotypic groups with no definite relation to any clinical events . These results indicate that many genotypes of Acinetobacter can cause adverse responses, and the initial source of the microorganisms rather than their clinical sequelae may determine classification.

Clin Experiment Ophthalmol, 2001 Jun, 29(3), 150 - 2
Production of N-acyl homoserine lactones by gram-negative bacteria isolated from contact lens wearers; Zhu H et al.; The purpose of this study was to investigate the production of N-acyl-homoserine lactone (AHL) signal molecules in ocular gram-negative bacteria . A total of 91 ocular strains isolated from contact lens adverse response patients and asymptomatic subjects were used in the study . These included Acinetobacter, Aeromonas hydrophila, Escherichia coli, Haemophilus influenzae, Klebsiella oxytoca, Pseudomonas aeruginosa, Serratia liquefaciens, Serratia marcescens, and Stenotrophomonas maltophilia . The biosensor strains Chromobacterium violaceum mutant CV026 and Agrobacterium tumefaciens A136 were used for detection of AHL signal molecules . The majority of A . hydrophila, P . aeruginosa, and S . liquefaciens strains produced more than one AHL molecule . Serratia marcescens strains were AHL positive only under detection of A136 . The rest of the test species did not show any AHL production under the current detection system . These findings indicate that AHL-mediated quorum-sensing systems are present in some of the ocular bacteria, and the different signal molecules may be involved with the quorum-sensing pathway in the other bacterial species.

FEMS Microbiol Lett, 2001 Jul 10, 201(1), 15 - 9
Spontaneous mutations affecting transcriptional regulation by protocatechuate in Acinetobacter; D'Argenio DA et al.; Positive selection yields Acinetobacter strains with a spontaneous mutation blocking catabolism of protocatechuate . For this study, the growth temperature during selection was lowered to 22 degrees C: growth at 37 degrees C was found to mask the role of the protocatechuate-responsive transcriptional regulator PcaU . The resulting mutants included those with amino acid substitutions useful for understanding PcaU structure and function, a 20-bp deletion whose repeated isolation suggested genetic instability of DNA in the putative PcaU operator, and a large deletion whose phenotype revealed that the supraoperonic cluster of genes for the protocatechuate branch of the beta-ketoadipate pathway extends to genes for the utilization of C(6)-C(10) straight-chain dicarboxylic acids including adipate.

J Med Microbiol, 2001 Jul, 50(7), 642 - 5
Clinical importance of extended-spectrum beta-lactamase (PER-1-type)-producing Acinetobacter spp . and Pseudomonas aeruginosa strains; Vahaboglu H et al.; Recently, an extended-spectrum beta-lactamase (PER-1) was found to be disseminated among Acinetobacter spp . and Pseudomonasaeruginosa isolates in Turkey . A population-based cohort study was conducted to elucidate predictive mortality factors in patients with nosocomial infections caused by Acinetobacter spp . and P . aeruginosa, with particular reference to PER-1-type extended-spectrum beta-lactamase (ESBL) production . The study group comprised 16 and 21 non-survivors and 82 and 126 survivors in cohorts infected with Acinetobacter and P . aeruginosa, respectively . In the Acinetobacter-infected cohort, nosocomial pneumonia, hypotension and infection with a PER-positive isolate were independent predictors of mortality . In the P . aeruginosa-infected cohort, impaired consciousness, a PER-positive isolate, male sex and (with a negative relative risk) urinary tract infection were independent predictors of death . This study demonstrated the relationship of PER-1-type ESBL-producing Acinetobacter spp . and P . aeruginosa with poor clinical outcome.

Clin Microbiol Infect, 2001 Jun, 7(6), 308 - 15
Resistance to antibiotics and biocides among non-fermenting Gram-negative bacteria; Higgins CS et al.; OBJECTIVE: To investigate the antibiotic and biocide susceptibilities of clinical isolates of rarely encountered Gram-negative, non-fermenting bacteria . METHODS: Thirty Gram-negative non-fermenting bacterial strains were isolated from blood cultures of oncology patients . These were studied for their resistance to 11 antibiotics . Their susceptibilities to seven biocides used in hospitals were also examined . RESULTS: Isolates of Stenotrophomonas maltophilia and Ochrobactrum anthropi were generally resistant to at least five of the antibiotics, whereas isolates of Comamonas acidivorans, Flavobacterium oryzihabitans, Aeromonas hydrophila, Sphingobacterium spiritivorum, Acinetobacter junii and Acinetobacter lwoffi were generally sensitive to at least nine of the antibiotics . Trovafloxacin and trimethoprim-sulfamethoxazole were the most effective antibacterial agents tested, with 0% and 7%, respectively, of isolates being resistant, whereas 63% of isolates were resistant to aztreonam . Some isolates, sensitive to meropenem and/or ceftazidime in vitro, possessed very high MBC/MIC ratios for these beta-lactams . Two out of three biocides used in hospital pharmacies showed lethal activity towards all strains tested when used at less than one-third of their recommended in-use concentration . Proceine 40 failed to give a 5 log reduction in bacterial cell number for the isolates tested when used at its "in-use" concentration . A concentration of > 500 mg/L chlorhexidine was required to achieve a 5 log reduction for the same isolates . CONCLUSIONS: We have examined the antibiotic susceptibilities of non-fermenting Gram-negative bacterial strains isolated from immunocompromised patients . Despite being sensitive to certain antibiotics in vitro, some isolates were still able to cause serious bacteremia . We have also reported for the first time the susceptibilities of non-fermenting Gram-negative bacteria to common biocides used in hospital infection control, and have shown that some strains are able to persist at the "in-use" concentration of particular biocides . It is therefore important to study further this particular group of organisms, and, in particular, to examine whether there exists a link between resistance to antibiotics and resistance to biocides.

J Hosp Infect, 2001 Jul, 48(3), 228 - 32
Investigation of an outbreak of multi-drug resistant Acinetobacter baumannii in an intensive care burns unit; Roberts SA et al.; Over a three month period there was an outbreak of infection, due to a multi-drug resistant Acinetobacter baumannii in the intensive care burns unit with spread of infection to other patients, both within the unit and elsewhere in the hospital.Microbiological sampling of the environment and of the healthcare workers' (HCWs) hands were carried out . Strain relatedness of the isolates was confirmed by pulsed field gel electrophoresis.Fifteen patients were involved in the outbreak, whose infections were all hospital-acquired . The burns room environment was contaminated with the A . baumannii, as was the door handle of the door leading from the ante-chamber between both rooms . This allowed the hands of HCWs to be contaminated by A . baumannii despite appropriate handwashing procedures prior to leaving the rooms . Two staff members were colonized with A . baumannii . One HCW who was directly involved in patient care was found to be "heavily" colonized, the other, with less patient contact, was only "lightly" colonized . Review of handwashing practices revealed that chlorhexidine/alcohol hand wash solution was not used by the HCW whose hands were heavily colonized.A combination of a review of handwashing practice, education about the spread of bacteria via hands and contaminated environment, and the revision of infection control procedures in the unit contributed to a prompt termination of the outbreak .

J Org Chem, 2001 Feb 9, 66(3), 733 - 8
Asymmetric Baeyer-Villiger oxidations of 4-mono- and 4,4-disubstituted cyclohexanones by whole cells of engineered Escherichia coli; Mihovilovic MD et al.; Whole cells of an Escherichia coli strain that overexpresses Acinetobacter sp . NCIB 9871 cyclohexanone monooxygenase have been used for the Baeyer-Villiger oxidations of a variety of 4-mono- and 4,4-disubstituted cyclohexanones . In cases where comparisons were possible, this new biocatalytic reagent provided lactones with chemical yields and optical purities that were comparable to those obtained from the purified enzyme or a strain of bakers' yeast that expresses the same enzyme . The efficient production of cyclohexanone monooxygenase in the E . coli expression system (ca . 30% of total soluble protein) allowed these oxidations to reach completion in approximately half the time required for the engineered bakers' yeast strain . Surprisingly, 4,4-disubstituted cyclohexanones were also accepted by the enzyme, and the enantioselectivities of these oxidations could be rationalized by considering the conformational energies of bound substrates along with the enzyme's intrinsic enantioselectivity . The enzyme expressed in E . coli cells also oxidized several 4-substituted cyclohexanones bearing polar substituents, often with high enantioselectivities . In the case of 4-iodocyclohexanone, the lactone was obtained in > 98% ee and its absolute configuration was assigned by X-ray crystallography . The crystal belongs to the monoclinic P2(1) space group with a = 5.7400(10), b = 6.1650(10), c = 11.377(2) A, b = 99.98(2) degrees, and Z = 2 . Taken together, these results demonstrate the utility of an engineered bacterial strain in delivering useful chiral building blocks in an experimentally simple manner.

Microbiology, 2001 Jul, 147(Pt 7), 1937 - 46
Analysis of the wee gene cluster responsible for the biosynthesis of the polymeric bioemulsifier from the oil-degrading strain Acinetobacter lwoffii RAG-1; Nakar D et al.; A cluster (27 kbp) of genes responsible for the biosynthesis of the amphipathic, polysaccharide bioemulsifier emulsan from the oil-degrading Acinetobacter lwoffii RAG-1 was isolated and characterized . The complete sequence of this cluster, termed wee, consisted of 20 ORFs . One set of 17 ORFs was transcribed in one direction, while a second set of three ORFs, 607 bp upstream of the first, was transcribed in the opposite direction . Mutations in either of the two regions caused defects in emulsan production, yielding specific activities of 5-14% of parental emulsifying activity . Putative functions could be assigned to proteins involved in production of nucleotide amino sugar precursors, transglycosylation, transacetylation, polymerization and transport . However, no JUMPstart or ops sequences, normally found associated with some polysaccharide biosynthetic gene clusters, were identified . Evidence is presented suggesting that the bioemulsifier may be a member of the group 1 or group 4 polysaccharides.

Transpl Infect Dis, 2000 Sep, 2(3), 133 - 9
Significant post-transplant hypogammaglobulinemia in six heart transplant recipients: an emerging clinical phenomenon?
Corales R, Chua J, Mawhorter S, Young JB, Starling R, Tomford JW, McCarthy P, Braun WE, Smedira N, Hobbs R, Haas G, Pelegrin D, Majercik M, Hoercher K, Cook D, Avery RK.
BACKGROUND: The recent development of powerful agents such as mycophenolate mofetil and tacrolimus has altered current regimens for the prevention and treatment of allograft rejection . Questions have been raised about these newer regimens in terms of susceptibility to opportunistic infections and effects on host defenses . Severe hypogammaglobulinemia has been infrequently described in solid organ transplant recipients, but has been recently noted in six heart transplant recipients at one center, of whom five were receiving a combination of tacrolimus, mycophenolate mofetil, and prednisone . METHODS: Case summaries of six recent heart transplant recipients with total immunoglobulin G (IgG) levels of less than 310 mg/dl, five of whom had cytomegalovirus (CMV) infection and three of whom had multiple infections including Nocardia, invasive Trichophyton, and Acinetobacter bacteremia . Previous literature was reviewed with the aid of a Medline search using the search terms hypogammaglobulinemia; kidney, liver, heart, lung, and organ transplantation; mycophenolate mofetil; tacrolimus; cyclosporine; azathioprine; and nocardiosis . RESULTS: We here report six cardiac transplant recipients seen over a period of one year who were found to have immunoglobulin G levels of 310 mg/dl or below (normal: 717-1400 mg/dl) . The first five patients were diagnosed because of evaluation for infections; the sixth, who was asymptomatic with an IgG level of 175, was found during screening for hypogammaglobulinemia instituted as a result of these first five patients . All six patients had received steroid pulses for rejection; all received mycophenolate mofetil; and 5/6 had been switched from cyclosporine to tacrolimus because of steroid-resistant rejection . Transient neutropenia (absolute neutrophil count less than 1000) was observed in 2/6; 3/6 had received OKT3 therapy for refractory rejection . These six patients were treated with a combination of antimicrobials, immunoglobulin replacement, and decrease in immunosuppressive therapy . CONCLUSION: The finding of unexpected hypogammaglobulinemia and concomitant infectious complications in six heart transplant recipients highlights a possible complication in a subset of patients receiving newer immunosuppressive agents . A larger prospective study is underway to determine risk factors for development of post-transplant hypogammaglobulinemia and to assess pre-transplant immune status of these recipients . Monitoring of immunoglobulin levels in high-risk patients receiving intensified immunosuppressive therapy for rejection may help to prevent infectious complications.

Infect Control Hosp Epidemiol, 2001 May, 22(5), 284 - 8
Antibiotic resistance is a major risk factor for epidemic behavior of Acinetobacter baumannii; Koeleman JG et al.; OBJECTIVE: To study the presence of bacterial factors in clinical isolates of Acinetobacter species in order to identify markers of epidemic potential . DESIGN: Case-control study . METHODS: Forty-six isolates of Acinetobacter species, including 23 epidemic and 23 sporadic strains from different outbreaks in nine European countries, were compared for the presence of the following factors: hemagglutination, presence of capsules and fimbriae, binding to salivary mucins, resistance to drying, and antibiogram typing . Genotyping of all strains was performed by amplified fragment-length polymorphism (AFLP) . RESULTS: All outbreak strains except two (91%) were identified as Acinetobacter baumannii . Binding to salivary mucins and resistance to antibiotics were significantly associated with epidemic behavior . Antibiogram typing showed clustering of predominantly A baumannii strains within one group, and these strains were significantly more resistant to antibiotics than sporadic strains . AFLP genotyping revealed a great heterogeneity among the different European Acinetobacter strains . Cluster analysis of AFLP fingerprints showed several small clusters of different A baumannii outbreak strains . AFLP genotyping could not identify a common epidemic marker within the strains studied . CONCLUSIONS: Antibiogram typing can be used in routine clinical laboratories as a screening method to recognize potentially epidemic A baumannii strains . Several other factors were found, both in different outbreaks as well as in sporadic Acinetobacter isolates . These characteristics were unable to predict epidemic behavior and therefore cannot be used as discriminative epidemic markers . AFLP genotyping demonstrated no common clonal origin of European epidemic A baumannii strains . This indicates that any clinical A baumannii isolate with resistance to multiple antibiotics can be a potential nosocomial outbreak strain.

J Clin Microbiol, 2001 Jul, 39(7), 2576 - 80
O-antigen diversity among Acinetobacter baumannii strains from the Czech Republic and Northwestern Europe, as determined by lipopolysaccharide-specific monoclonal antibodies; Pantophlet R et al.; O-antigen-specific monoclonal antibodies (MAbs) are currently being generated to develop an O-serotyping scheme for the genus Acinetobacter and to provide potent tools to study the diversity of O-antigens among Acinetobacter strains . In this report, Acinetobacter baumannii strains from the Czech Republic and from two clonal groups identified in Northwestern Europe (termed clones I and II) were investigated for their reactivity with a panel of O-antigen-specific MAbs generated against Acinetobacter strains from various species . The bacteria were characterized for their ribotype, biotype, and antibiotic susceptibility and the presence of the 8.7-kb plasmid pAN1 . By using the combination of these typing profiles, the Czech strains could be classified into four previously defined groups (A . Nemec, L . Janda, O . Melter, and L . Dijkshoorn, J . Med . Microbiol . 48:287-296, 1999): two relatively homogeneous groups of multiresistant strains (termed groups A and B), a heterogeneous group of other multiresistant strains, and a group of susceptible strains . O-antigen reactivity was observed primarily with MAbs generated against Acinetobacter calcoaceticus and Acinetobacter baumannii strains . A comparison of reaction patterns confirmed the previously hypothesized clonal relationship between group A and clone I strains, which are also similar in other properties . The results show that there is limited O-antigen variability among strains with similar geno- and phenotypic characteristics and are suggestive of a high prevalence of certain A . baumannii serotypes in the clinical environment . It is also shown that O-antigen-specific MAbs are useful for the follow-up of strains causing outbreaks in hospitals.

Clin Diagn Lab Immunol, 2001 Jul, 8(4), 825 - 7
Generation and serological characterization of murine monoclonal antibodies against O antigens from Acinetobacter reference strains; Pantophlet R et al.; O-antigen-specific monoclonal antibodies were generated against Acinetobacter strains from international type culture collections and characterized by enzyme immunoassay and Western and colony blotting . The antibodies aid in the further completion of an O-serotyping scheme for Acinetobacter and, due to their high specificity, are especially useful to all working with these strains.

FEMS Microbiol Lett, 2001 Jun 25, 200(2), 247 - 52
Protein synthesis patterns in Acinetobacter calcoaceticus induced by phenol and catechol show specificities of responses to chemostress; Benndorf D et al.; The proteins induced in Acinetobacter calcoaceticus by the potentially toxic growth substrates phenol and catechol were analyzed by 2D-electrophoresis of cell extracts and compared with those induced by heat shock and oxidative stress . Although both aromatic compounds are quite similar, the only difference being that catechol has an additional hydroxyl group, the responses obtained differed considerably . Phenol has greater lipophilicity and mainly induced heat shock proteins, whereas catechol, which causes the production of reactive oxygen species, predominantly induced oxidative stress proteins . Furthermore, some special proteins were induced by phenol or catechol, which might be useful as biomarkers for chemostress, and could be involved in the catalytic degradation of potentially toxic compounds.

Electrophoresis, 2001 May, 22(9), 1705 - 11
Media containing aromatic compounds induce peculiar proteins in Acinetobacter radioresistens, as revealed by proteome analysis; Giuffrida MG et al.; An Acinetobacter radioresistens strain able to grow on phenol or benzoate as sole carbon and energy source through the beta-ketoadipate pathway was isolated in our laboratories . In previous research, we found a different expression of catechol-1,2-dioxygenase isoenzymes (C-1,2-O) depending on the growth substrate (phenol or benzoate) . In the present study, we used proteome techniques to extend our investigation to other enzymes involved in the aromatic degradation pathway . Since the first nontoxic metabolite in this route is cis,cis-muconic acid, we focused our attention on the enzymes leading to this compound, chiefly phenol hydroxylase (PH), benzoate dioxygenase (BD), cis-1,2-dihydroxycyclohexa-3,5-diene-1-carboxylate dehydrogenase (D) and C-1,2-O . In particular, the A . radioresistens proteome was monitored under different growth substrate conditions, using acetate, benzoate, or phenol as sole carbon source . We compared the protein maps by software image analysis and detected marked differences, suggesting the inducibility of most enzymes . This research also sought to evaluate the conditions allowing the best expression of enzymes to be used in immobilized systems suitable for bioremediation . The experimental data indicate that benzoate is the best carbon source to gain the highest amount of C-1,2-O and D, while phenol is the best growth substrate to obtain PH.

Microbios, 2001, 105(412), 153 - 61
A new extraction method for Acinetobacter species ODB-L2 rough form lipopolysaccharide from culture broth; Kunii K et al.; The Gram-negative bacterium Acinetobacter species ODB-L2 produces lipopolysaccharide (LPS) in culture broth . The LPS could not be purified by conventional extraction methods using 90% phenol/water or 90% phenol/chloroform/petroleum ether mixed solvent . Extraction was achieved employing an admixture of chloroform, ethanol, and 4 M HCI solution . The LPS was purified from dissolving the crude extracts in 90% phenol and LPS sediment formed by addition of methanol . The LPS was characterized by chemical, biochemical, and physicochemical methods as rough form 3-hydroxydodecanoic acid rich LPS.

Cornea, 2001 Jul, 20(5), 463 - 6
Association of acinetobacter species with contact lens-induced adverse responses; Corrigan KM et al.; PURPOSE: To determine the levels of Acinetobacter species associated with normal soft contact lens wear and to determine whether Acinetobacter species are involved in adverse reactions that occur during contact lens wear . METHODS: Patients wore soft contact lenses on an extended-wear basis . The bacteria on lenses and ocular swabs during asymptomatic and symptomatic lens wear were identified using standard microbiologic methods . RESULTS: Acinetobacter species were isolated and identified from 16 (13%) of 126 patient samples . Greater numbers of Acinetobacter species were isolated from lenses of patients experiencing adverse responses than from asymptomatic patients.Acinetobacter species were isolated from patients experiencing symptomatic adverse responses in 4 (13%) of 32 cases . CONCLUSION: It appeared that Acinetobacter species colonized the eye of extended contact lens wearers at a time when the normal functioning of the eye was compromised by contact lens wear . When Acinetobacter species were in high numbers on a contact lens, an adverse response occurred . This may implicate Acinetobacter species as a contributing factor to adverse responses associated with contact lens wear.

Diagn Microbiol Infect Dis, 2001 Apr, 39(4), 215 - 23
Efficacy of two DNA fingerprinting methods for typing Acinetobacter baumannii isolates; Quelle LS et al.; Performance of macrorestriction and repetitive extragenic palindromic DNA sequence-based PCR (REP-PCR) to type Acinetobacter baumannii isolates was quantitatively estimated using a test population of 54 outbreak-related, 29 endemic infection-related and 17 epidemiologically-unrelated isolates . Reproducibility and stability for macrorestriction were 100%, and REP-PCR showed only slightly lower stability . Macrorestriction resolved 18 fingerprints and REP-PCR 10 DNA patterns, forming eight and seven clusters at 75% of similarity level, respectively . Intercluster band variation was > 7 bands for both methods . Although, all endemic isolates, except one, were concordantly grouped by both methods, macrorestriction distinguished a greater number of subtypes over one year study . For outbreaks, the epidemiologic concordance for both methods was 88% . The discriminatory index for macrorestriction and REP-PCR was 0.884 and 0.877, respectively . In conclusion, both methods showed similar efficacy as epidemiological markers, and by concordance, this study demonstrated that for REP-PCR typing, a > or = 7 bands difference seemed an appropriate threshold to identify unrelated strains.

J Biol Chem, 2001 Sep 14, 276(37), 34465 - 72 Epub 2001 Jun 14.
Xyloside transport by XylP, a member of the galactoside-pentoside-hexuronide family; Heuberger EH et al.; This paper describes the functional characterization of the xyloside transporter, XylP, of Lactobacillus pentosus with the aid of a spectroscopy-based assay system . In order to monitor the transport reaction, the natural xyloside isoprimeverose, a building block of hemicellulose, and the analogue methyl-isoprimeverose were chemically synthesized by a new and efficient procedure . The XylP protein was purified by metal affinity chromatography, following high level expression in Lactococcus lactis from the nisin-inducible promoter . The purified XylP protein was incorporated into liposomes, in which the glucose dehydrogenase from Acinetobacter calcoaceticus (sGDH) was entrapped . sGDH can oxidize aldose sugars in the presence of dichlorophenol-indophenol as electron acceptor . The coupled assay thus involves XylP-mediated isoprimeverose uptake followed by internal oxidation of the sugar by sGDH, which can be monitored from the reduction of 2,6-dichlorophenol-indophenol at 600 nm . The uptake of isoprimeverose was stimulated by the presence of the non-oxidizable methyl-isoprimeverose on the trans-side of the membrane, indicating that exchange transport is faster than unidirectional downhill uptake . Unlike other members of the galactoside-pentoside-hexuronide family, XylP does not transport monosaccharides (xylose) but requires a glycosidic linkage at the anomeric carbon position . Consistent with a proton motive force-driven mechanism, the uptake was stimulated by a membrane potential (inside negative relative to outside) and inhibited by a pH gradient (inside acidic relative to outside) . The advantages of the here-described transport assay for studies of carbohydrate transport are discussed.

Chemotherapy, 2001 Jul-Aug, 47(4), 304 - 8
Evaluation of spontaneous contamination of ocular medications; Marchese A et al.; BACKGROUND: In order to evaluate whether single-dose ophthalmic preparations in 0.5-ml containers can safely be used within 24 h after the first opening, eigth different sterile ocular medications containing timolol, jaluronic acid, diclofenac, ketotifen, pilocarpine, formocortal, formocortal-gentamycin, and tetryzoline-feniramine (Farmigea, Italy) were opened and tested for spontaneous bacterial contamination after exposure to air . METHODS: Samples (10 microl) were collected from exposed ophthalmic preparations after 0, 2, 4, 8 and 24 h . RESULTS: No viable microorganisms were detected during and at the end of the evaluation period . In order to assess whether the resident or pathogenic ocular bacterial population due to repeated handling might contaminate the medications, about 10(5) cells of different species (Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus pneumoniae, Streptococcus spp., Corynebacterium spp., Pseudomonas aeruginosa, Neisseria spp., Acinetobacter spp., Haemophilus influenzae, Escherichia coli and Candida albicans) were added to the containers and incubated at 37 degrees C or at room temperature . Samples were collected and the number of viable bacteria was estimated . The antibacterial effect of the ophthalmic compounds varied depending on the species considered . Tetryzoline-feniramine, pilocarpine, ketotifen and formocortal-gentamycin exhibited a frank bactericidal activity (<100 survivors after 18-24 h of exposure) against the great majority of the species tested . CONCLUSION: These results indicate that the risk of spontaneous contamination of ophthalmic preparations after their first opening is low, and that all preparations tested exhibit an aspecific antibacterial activity . As a consequence, the safe usage of these ocular medications could be extended from the recommended 3 h to at least 24 h after the first usage.

Syst Appl Microbiol, 2001 Apr, 24(1), 122 - 30
Comparison of the antimicrobial tolerance of oxytetracycline-resistant heterotrophic bacteria isolated from hospital sewage and freshwater fishfarm water in Belgium; Huys G et al.; The aim of this study was to investigate the relationship between antimicrobial tolerance and taxonomic diversity among the culturable oxytetracycline-resistant (Ot(r)) heterotrophic bacterial population in two Belgian aquatic sites receiving wastewater either from human medicine or from aquaculture . The study of Ot(r) heterotrophs and mesophilic Aeromonas spp . allowed comparison of tolerance data at the intergenus as well as at the intragenus level . In total, 354 independently obtained Ot(r) isolates were subjected to antimicrobial tolerance testing and identified by GLC analysis of their cellular fatty acid methyl esters (FAMEs), by API 20E profiling and/or by Fluorescent Amplified Fragment Length Polymorphism (FAFLP) DNA fingerprinting . In general, Ot(r) hospital heterotrophs displayed a higher frequency (84%) of ampicillin (Amp) tolerance compared to the Ot(r) heterotrophs from the freshwater fishfarm site (22%) . FAME results indicated that this effect was linked to the predominance of intrinsically ampicillin-resistant Ot(r) Aeromonas strains over representatives of Acinetobacter and Escherichia coli within the hospital strain set . Among the Ot(r) mesophilic Aeromonas strain set, the global tolerance profiles of the two sites only differed in a higher number of kanamycin (Kan) -tolerant strains (43%) for hospital aeromonads in comparison with the fishfarm aeromonads (8%) . To some extent, this finding was correlated with the specific presence of Aeromonas caviae DNA hybridisation group (HG) 4 . Collectively, these results suggest that the profiles for Amp and Kan tolerance observed in both sites arose from taxonomic differences in the culturable Ot(r) bacterial population at the generic or subgeneric level . In addition, our identification data also revealed that Enterobacter sp., Stenotrophomonas maltophilia, and A . veronii biovar sobria HG8 may be considered potential indicator organisms to assess microbial tolerance in various compartments of the aquatic environment.

Curr Microbiol, 2001 Jun, 42(6), 408 - 14
Photoinactivation of Acinetobacter baumannii and Escherichia coli B by a cationic hydrophilic porphyrin at various light wavelengths; Nitzan Y et al.; Photodynamic treatment by the cationic TMPyP photosensitizer was undertaken on the multiple antibiotic-resistant bacteria Acinetobacter baumannii and Escherichia coli . Total eradication of the bacterial cultures was determined immediately after initiation of illumination when these bacteria were treated with 5, 10, 15, 20-tetra (4-N methylpyridyl)porphine (TMPyP) at a concentration of 29.4 micromol/L and illuminated by blue, green, or red light . Total eradication of both bacteria was obtained also after treatment of bacterial cultures with 3.7 micromol/L TMPyP and illumination with blue light (400-450 nm) . On the other hand, an 8- or 16- to 20-fold higher light intensity, respectively, was required for total eradication upon illumination with green (480-550 nm) or red light (600-700 nm) . A 407-nm blue light only 7 and 9 joules/cm2, respectively, was needed for total eradication of both bacteria even at a concentration of 3.7 micromol/L TMPyP . X-ray-linked microanalysis demonstrated loss of potassium and a flood of sodium and chloride into the cells, indicating serious damage to the cytoplasmic membrane . Transmission electron microscopy (TEM) revealed structural changes and damage to the membrane of treated E . coli . In A . baumannii-treated cells, mesosomes and black dots that resemble aggregation of polyphosphate polymers could be seen . DNA breakage appeared only after a long period of illumination, when the bacterial cell was no longer viable . It can be concluded that cytoplasmic membrane damage and not DNA breakage is the major cause for bacterial death upon photosensitization.

Appl Environ Microbiol, 2001 Jun, 67(6), 2507 - 14
Cloning and expression of the benzoate dioxygenase genes from Rhodococcus sp . strain 19070; Haddad S et al.; The bopXYZ genes from the gram-positive bacterium Rhodococcus sp . strain 19070 encode a broad-substrate-specific benzoate dioxygenase . Expression of the BopXY terminal oxygenase enabled Escherichia coli to convert benzoate or anthranilate (2-aminobenzoate) to a nonaromatic cis-diol or catechol, respectively . This expression system also rapidly transformed m-toluate (3-methylbenzoate) to an unidentified product . In contrast, 2-chlorobenzoate was not a good substrate . The BopXYZ dioxygenase was homologous to the chromosomally encoded benzoate dioxygenase (BenABC) and the plasmid-encoded toluate dioxygenase (XylXYZ) of gram-negative acinetobacters and pseudomonads . Pulsed-field gel electrophoresis failed to identify any plasmid in Rhodococcus sp . strain 19070 . Catechol 1,2- and 2,3-dioxygenase activity indicated that strain 19070 possesses both meta- and ortho-cleavage degradative pathways, which are associated in pseudomonads with the xyl and ben genes, respectively . Open reading frames downstream of bopXYZ, designated bopL and bopK, resembled genes encoding cis-diol dehydrogenases and benzoate transporters, respectively . The bop genes were in the same order as the chromosomal ben genes of P . putida PRS2000 . The deduced sequences of BopXY were 50 to 60% identical to the corresponding proteins of benzoate and toluate dioxygenases . The reductase components of these latter dioxygenases, BenC and XylZ, are 201 residues shorter than the deduced BopZ sequence . As predicted from the sequence, expression of BopZ in E . coli yielded an approximately 60-kDa protein whose presence corresponded to increased cytochrome c reductase activity . While the N-terminal region of BopZ was approximately 50% identical in sequence to the entire BenC or XylZ reductases, the C terminus was unlike other known protein sequences.

J Environ Monit, 2001 Feb, 3(2), 206 - 9
Suspended particulates and bioaerosols emitted from an agricultural non-point source; Hameed AA et al.; Suspended particulate and bioaerosol levels were measured at three sites downwind of an agricultural non-point source during the wheat harvesting season . Suspended particulates were detected at mean values ranging from 10000 to 2420 micrograms m-3 at distances of from 20 to 60 m downwind of the source, respectively . Airborne viable bacterial counts were recorded at mean values ranging between 10(4) and 10(6) colony forming units (cfu) m-3, whereas, Gram negative (Gram -ve) bacteria varied between 10(3) and 10(5) cfu m-3 . Fungi levels were detected at mean values varying between 10(5) and 10(6) cfu m-3 . However, streptomycetes were found at lower counts than those recorded for viable bacteria and fungi . Total viable bacteria, Gram -ve bacteria, fungi and streptomycetes associated hay fragments were determined at mean values of 1.5 x 10(6), 1.6 x 10(3), 2.2 x 10(4) and 6 x 10(3) cfu g-1 of hay, respectively . Cladosporium, white and red yeasts as well as Alternaria were the predominant airborne fungi, whereas, Alternaria was the dominant species associated with hay fragments . Pseudomonas, Acinetobacter and Enterobacteriaceae were the dominant Gram -ve bacteria . The most common fungal genera, such as Cladosporium and Fusarium (minor short axis), as well as Streptomyces species have an aerodynamic diameter (dae) of less than 5 microns, which can penetrate and deposit in the alveoli . Farmers and nearby residents are exposed to high levels of organic dust and bioaerosols during the wheat harvesting season . This may cause health problems in exposed persons based on toxic or allergic reactions.

Biochem Biophys Res Commun, 2001 Apr 13, 282(4), 899 - 903
ESI- and MALDI-MS analysis of cyclohexanone monooxygenase from acinetobacter NCIB 9871; Kneller MB et al.; Recombinant and native forms of cyclohexanone monooxygenase (CMO) from Acinetobacter NCIB 9871 were analyzed by mass spectrometry to probe ambiguities arising from the presence of multiple DNA sequences for the enzyme in GenBank . A CMO gene corresponding exactly to the nucleotide sequence described by Iwaki et al . (10) was amplified from genomic DNA, cloned into pET15b, and the recombinant protein purified from a bacterial expression system . Electrospray mass spectrometry of both the recombinant material and the native form of CMO isolated from Acinetobacter yielded molecular weights within 0.01% of those predicted from the translated gene sequence of Iwaki et al . (10) . Trypsin and chymotrypsin digests of native CMO, analyzed by electrospray and MALDI mass spectrometry, provided greater than 97% coverage of the protein and confirmed the presence of specific peptide sequences predicted by the Iwaki sequence alone . Therefore, the primary sequence of native Acinetobacter CMO is identical to the gene sequence for chnB deposited under accession number AB006902 .

Environ Sci Technol, 2001 Feb 1, 35(3), 528 - 34
Response of sediment bacterial assemblages to selenate and acetate amendments; Lucas FS et al.; We followed the response of bacterial assemblages in slurries of estuarine sediments to amendments of 100 microM sodium selenate and 10 mM sodium acetate . Selenate was removed from the dissolved phase in all slurries after an initial lag that varied depending on the source of the sediment used in the slurry . Subsequent selenate amendments were removed without a lag but with the appearance of transient peaks of selenite . We documented changes in the composition of bacterial assemblages in the slurries using PCR/DGGE and RT-PCR/DGGE of 16S rDNA and rRNA . Bands of interest were sequenced to identify organisms responding to selenate amendments . The composition of communities from the two sampling sites was different and changed but did not converge during incubations with selenate . Selenate-reducing assemblages had broad phylogenetic diversity . Most bands were related to groups of bacteria known to contain organisms capable of selenate or selenite reduction, except for Acinetobacter species which dominated one of the samples and has not previously been associated with selenium oxyanion reduction.

Przegl Epidemiol, 2000, 54(3-4), 259 - 69
{Hospital acquired pneumonia--analysis of frequency and etiology in Polish hospitals in 1998}; Pietrzyk A et al.; Hospital-acquired pneumonia (HAP) is one of the most frequently occurring hospital infections in the world . This study describes the incidence of HAP in Poland, as well as the specific risk factors leading to this type of infection in Polish hospitals; including those of patient age, length of hospitalization, and use of mechanical ventilation . The epidemiology of HAP as well as treatment resistance of various causal organisms was studied . Data for this study was acquired from the Registry of Hospital-acquired Infectious Diseases for the year 1998 . Out of 329,608 hospital-acquired infections in all patients except newborns, 920 were found to be HAP . This study showed that of every 1000 hospital admissions three patients developed HAP (0.3%) . Death occurred in 260 of 920 HAP cases or 30%; and HAP found to be the direct cause of death in 66 of the 260 cases (25%) . The greatest incidence of HAP was found to occur in patients older than 75 years, was directly related to the length of hospital stay, and was higher in patients on mechanical ventilation longer than 10 days . The most frequently isolated causal agents were the Gram-negative rods (Pseudomonas aeruginosa, Acinetobacter sp., Klebsiella sp., Enterobacter sp.), and Staphylococcus aureus . Streptococcus pneumoniae and Haemophilus influenzae were found in only 2% and 4% of cases, respectively, and thus were the least likely causes of HAP in this population . It was found that the percentage of methicillin-resistant strains of Staphylococcus aureus was very high (55% to 60%); vancomycin-resistant enterococci were only found in patients who did not undergo surgery . The isolated strains of Pseudomonas aeruginosa showed marked resistance to chinolones (58-76%) and to imipen (approximately 20%) . In the Enterobacteriaceae family, Klebsiella sp . was found to be resistant to third-generation cephalosporins (56-73%) and Enterobacter sp . resistant in 55% to 81% of the isolates.

Int J Antimicrob Agents, 2001 May, 17(5), 357 - 63
Antibiotic selective pressure and development of bacterial resistance; Kolar M et al.; This study evaluates the development of resistance in Gram-negative rods to cefotaxime and ceftazidime, ofloxacin and ciprofloxacin, gentamicin and amikacin, meropenem and ampicillin/sulbactam over a five year period of use (1994-1998) at the University Hospital in Olomouc, Czech Republic . The development of bacterial resistance was linked with antibiotic use and hence selective pressure which was specific for the type of antibiotic and the bacterial species . Statistically significant correlations were found for the use of ofloxacin and resistance in Escherichia coli, Proteus vulgaris and Providencia rettgeri; cefotaxime and Enterobacter cloacae; ceftazidime and Acinetobacter spp., Enterobacter agglomerans and Proteus vulgaris; and gentamicin and Proteus mirabilis.

J Med Assoc Thai, 2001 Feb, 84(2), 160 - 5
Nosocomial bloodstream infection in pediatric patients: Siriraj Hospital, Bangkok; 1996-1999; Mongkolrattanothai K et al.; A retrospective study on nosocomial bloodstream infection (NBSI) in pediatric patients hospitalized at Siriraj Hospital from January 1996 to December 1999 was performed . Of the 18,087 blood specimens sent for culture, 533 (3%) were positive for organisms after 72 hours of hospitalization and were defined as NBSI . The rate of NBSI detected in blood culture specimens was highest among neonates (5.2%) . Gram-positive cocci and gram-negative rods caused NBSI in an equal proportion (46% and 44% respectively) and Candida caused 10 per cent of NBSI . Coagulase-negative staphylococci was the most common pathogen followed by K . pneumoniae and Enterobacter . Antibiogram showed that 15 of the 35 (43%) S . aureus identified were methicillin-resistant . Only 35-38 per cent of Enterobacteriaceae were sensitive to cefotaxime or ceftazidime . Cefoxitin was still effective against 95 per cent of K . pneumoniae . Compared with other third generation cephalosporins, combination of cefoperazone and betalactamase-inhibitor (sulbactam) possessed an increased in vitro efficacy against K . pneumoniae, Enterobacter, E . coli, Acinetobacter and non-fermentative gram-negative rods . Resistant rate of amikacin among all gram negative rods was 25-69 per cent . Ciprofloxacin sensitivity varied from 62-100 per cent among all gram-negative rods . Imipenem was excellent against all gram-negative rods with the sensitivity of 80-100 per cent . Epidemiological data of this study is important for the decision of the appropriate empirical antimicrobial treatment in our hospital.

J Chemother, 2001 Apr, 13(2), 143 - 7
Transferable antibiotic resistance in multiresistant nosocomial Acinetobacter baumannii strains from seven clinics in the Slovak and Czech Republics; Blahova J et al.; Sixty-seven multiresistant nosocomial Acinetobacter baumannii isolates from patients hospitalized mostly in intensive care units of seven clinics in Slovak and Czech Republic were tested to determine their ability to transfer antibiotic resistance . All isolates were resistant to kanamycin, ticarcillin, cephalothin, cefotaxime, ceftazidime, aztreonam and susceptible to carbapenems, sulbactam and ampicillin/sulbactam . Sixty-five out of 67 strains transferred resistance determinants to Escherichia coli K-12 and Proteus mirabilis P-38 recipients . Analysis of selected transconjugants by an indirect selection method showed a more variable pattern of transferred resistance determinants . The clonal spread of strains transferring resistance seems to be an additional risk for occurrence of strains resistant to ceftazidime and aztreonam.

J Chemother, 2001 Apr, 13(2), 133 - 42
Antibiotic use and development of resistance in blood culture isolates: 8 years of experience from a cancer referral center; Krcmery V Jr et al.; The consumption of antimicrobial agents in a Slovakian national cancer institute from 1989-1996 was compared with resistance rates in clinically significant blood culture isolates . We observed an increase in resistance of viridans streptococci to penicillin and of enterococci to ampicillin . Resistance to vancomycin and teicoplanin was stable over the entire period despite a 20-fold increase in vancomycin consumption . Nor did we observe increased resistance to ofloxacin despite a 10-fold increase in consumption . Consumption of aminoglycosides and resistance levels were both stable . A different situation was observed with third-generation cephalosporins, where resistance of Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Acinetobacter spp . to ceftazidime and cefotaxime increased with increasing consumption . Resistance of Enterobacteriaceae to cefotaxime and ceftazidime was stable . Resistance to imipenem did not change significantly . However, the number of Stenotrophomonas maltophilia bacteremias increased significantly after imipenem was introduced in 1991 . Because of improved outcome in bacteremia, an increased incidence of both gram-negative and gram-positive bacteremia led to only a slight increase in associated mortality.

Invest Ophthalmol Vis Sci, 2001 May, 42(6), 1164 - 71
16S rDNA-based identification of bacteria from conjunctival swabs by PCR and DGGE fingerprinting; Schabereiter-Gurtner C et al.; PURPOSE . Establishment of a new molecular biology technique for the identification of multiple bacteria from the ocular environment, which can be applied supplementarily to cultivation in cases of severe bacterial infections . METHODS . From 60 human conjunctivae (29 with purulent and 31 with nonpurulent conjunctivitis), swabs were taken and DNA was extracted . Fragments of 200 bp, spanning the V3 region of the eubacterial 16S rDNA, were amplified by polymerase chain reaction (PCR) and separated by denaturing gradient gel electrophoresis (DGGE) . For phylogenetic identification, DGGE bands were excised and directly sequenced, or 16S rDNA clone libraries were constructed and clones were screened by DGGE . Sequences were compared with sequences of known bacteria listed in the EMBL database . Furthermore, the results were compared with results obtained from conventional cultivation . RESULTS . 16S rDNA could be amplified from 25 of 29 investigated swabs taken from purulent conjunctivitis eyes and from 2 of 31 investigated swabs taken from nonpurulent conjunctivitis eyes . Sixteen samples showed monomicrobial and 11 samples showed polymicrobial infections . The following genera (n is number of samples) were detected: Staphylococcus (n = 8), Corynebacterium (n = 7), Propionibacterium (n = 7), Streptococcus (n = 6), Bacillus (n = 2), Acinetobacter (n = 3), Pseudomonas (n = 3), Proteus (n = 1), and Brevundimonas (n = 1) . Four sequences could not be identified to the genus level . They had highest sequence similarities both to sequences of Pantoea and Enterobacter (n = 1), Kingella and Neisseria (n = 1), Serratia and Aranicola (n = 1), and Leuconostoc and Weissella (n = 2), respectively . Culture was only positive for coagulase-negative staphylococci (n = 9), Corynebacteria (n = 3), Staphylococcus aureus (n = 1), Streptococcus sp . (n = 1), Proteus sp . (n = 1), Klebsiella oxytoca (n = 1), and Pseudomonas aeruginosa (n = 1) . In total, 45% of the 60 analyzed conjunctival swabs were PCR positive, whereas only 22% were culture positive . No sample positive by culture gave negative results by PCR . CONCLUSIONS . 16S rDNA sequence analyses and DGGE fingerprinting are appropriate methods for the detection and identification of monomicrobial as well as polymicrobial ocular infections of bacteria that might not be detected by conventional cultivation.

J Clin Microbiol, 2001 May, 39(5), 1707 - 9
Detection and culture of Bartonella quintana, Serratia marcescens, and Acinetobacter spp . from decontaminated human body lice; La Scola B et al.; As part of a survey for trench fever among homeless people in Marseilles, France, we attempted isolation of Bartonella quintana from body lice . A decontamination protocol of immersion in 70% ethanol with 0.2% iodine was devised and was tested with a laboratory colony of body lice . Lice which had been experimentally contaminated with either Escherichia coli, Staphylococcus epidermidis, or Acinetobacter spp . were successfully decontaminated, and this process did not prevent the culture of B . quintana from these lice . One hundred sixty-one lice obtained from homeless patients were studied by the protocol . B . quintana was isolated on axenic medium from 15 of 161 body lice and was detected in 41 of 161 lice by PCR . Acinetobacter spp . and Serratia marcescens were also isolated from body lice . The sensitivities of PCR and culture of B . quintana were 98 and 36%, respectively . These procedures may be useful for epidemiologic studies of trench fever and for the recovery of strains for characterization and comparison.

Pol Merkuriusz Lek, 2001 Feb, 10(56), 80 - 2
{Activity of cefepime compared with other antibiotics against major hospital bacterial pathogens}; Hryniewicz W et al.; The aim of the study was to evaluate susceptibility of 976 bacterial isolates from nosocomial infections to cefepime and 9 other antibiotics used in the treatment of hospitalised patients . Bacterial strains were mainly derived from wound and soft tissue infections, sputum, abscesses and blood . The most prevalent etiologic agents were: Pseudomonas aeruginosa (18.7%), Escherichia coli (13.8%), Staphyloccocus aureus (9.7%, Acinetobacter baumannii (9.12%), Klebsiella pneumoniae (7.38%), Enterobacter cloacae (5.6%) . The most susceptible to cefepime were strains of K . pneumoniae (98.62%), E . coli (98.52%) and E . cloacae (98.19%) including those producing extended spectrum beta-lactamases . The degree of susceptibility to cefepime was equal to that of imipenem . A . baumannii was the least susceptible species (67.42%) . This study indicate that cefepime may play an important role in therapy of nosocomial infections in particular caused by Enterobacteriace.

Clin Infect Dis, 2001 May 15, 32 Suppl 2, S156 - 67
Integration of molecular characterization of microorganisms in a global antimicrobial resistance surveillance program; Pfaller MA et al.; The SENTRY Antimicrobial Surveillance Program has incorporated molecular strain typing and resistance genotyping as a means of providing additional information that may be useful for understanding pathogenic microorganisms worldwide . Resistance phenotypes of interest include multidrug-resistant pathogens, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci, and fluoroquinolone-resistant (FQR) strains of gram-negative bacilli and Streptococcus pneumoniae . Clusters of > or =2 isolates within a given resistance profile that are linked temporally and by hospital location are flagged for DNA fingerprinting . Further characterization of organisms with respect to resistance genotype is accomplished with use of polymerase chain reaction and DNA sequencing . This process has been highly successful in identifying clonal spread within clusters of multiresistant pathogens . Between 50% and 90% of MRSA clusters identified by phenotypic screening contained evidence of clonal spread . Among the Enterobacteriaceae, ESBL-producing strains of Escherichia coli and Klebsiella pneumoniae are the most common pathogens causing clusters of infection, and approximately 50% of recognized clusters demonstrate clonal spread . Clusters of Pseudomonas aeruginosa, Acinetobacter species, and Stenotrophomonas maltophilia have been noted with clonal spread among patients with urinary tract, respiratory, and bloodstream infections . Characterization of mutations in the FQR-determining region of phenotypically susceptible isolates of E . coli and S . pneumoniae has identified first-stage mutants among as many as 40% of isolates . The ability to characterize organisms phenotypically and genotypically is extremely powerful and provides unique information that is important in a global antimicrobial surveillance program.

Clin Infect Dis, 2001 May 15, 32 Suppl 2, S104 - 13
Emerging importance of multidrug-resistant Acinetobacter species and Stenotrophomonas maltophilia as pathogens in seriously ill patients: geographic patterns, epidemiological features, and trends in the SENTRY Antimicrobial Surveillance Program (1997-1999); Gales AC et al.; As part of the SENTRY Antimicrobial Surveillance Program, a total of 1078 Acinetobacter species and 842 Stenotrophomonas maltophilia isolates were collected between January 1997 and December 1999 from 5 geographic regions (Canada, the United States, Latin America, Europe, and the Asia-Pacific) . The frequency of infections (by geographic region and body site), including those due to imipenem-resistant Acinetobacter species and trimethoprim-sulfamethoxazole (TMP-SMZ)-resistant S . maltophilia, was evaluated . The possibility of seasonal variations in bloodstream infections caused by Acinetobacter species was studied, as was the activity of several therapeutic antimicrobials against all strains . Acinetobacter species and S . maltophilia were most frequently associated with pulmonary infections, independent of the region evaluated . In contrast, patterns of antimicrobial resistance markedly varied among distinct geographic regions, especially for nosocomial isolates . Although the carbapenems were the most active antimicrobials against Acinetobacter species, nearly 11.0% of the nosocomial isolates were resistant to this drug group in both regions . TMP-SMZ, ticarcillin-clavulanic acid, gatifloxacin, and trovafloxacin were the only agents with consistent therapeutic activity against S . maltophilia isolates . Rates of resistance to TMP-SMZ ranged from 2% in Canada and Latin America to 10% in Europe . The geographic differences in resistance patterns among Acinetobacter species and S . maltophilia isolates observed in this study emphasize the importance of local surveillance in determining the most adequate therapy for acinetobacter and S . maltophilia infections and the possible clonal, epidemic nature of occurrence.

Mikrobiologiia, 2000 Sep-Oct, 69(5), 674 - 80
{Isolation and study of Acinetobacter sp . mutant strains defective in production of exopolysaccharides}; Pirog TP et al.; Nitrosoguanidine-induced mutants of Acinetobacter sp . defective in exopolysaccharide biosynthesis did not differ from the parent strain in distinguishing physiological and biochemical properties, such as requirements for growth factors, utilization of mono- and disaccharides, and resistance to antibiotics . The genetic relation of parent and mutant strains was shown by 16S rRNA PCR analysis . The comparative study of parent and mutant strains with respect to resistance to unfavorable environmental factors confirmed our hypothesis that Acinetobacter sp . exopolysaccharides perform protective functions . Hybridization experiments revealed the conjugal transfer of plasmid R68.45 from Pseudomonas putida BS228 (R68.45) to mutant but not to the parent Acinetobacter sp . strains . The role of the Acinetobacter sp . exopolysaccharides in providing the genetic stability of this bacterium is discussed.

Can J Microbiol, 2001 Mar, 47(3), 194 - 205
Effects of low temperature, cold shock, and various carbon sources on esterase and lipase activities and exopolysaccharide production by a psychrotrophic Acinetobacter sp; Barbaro SE et al.; The activities of isocitrate lyase, esterase, and lipase by the psychrotrophic Acinetobacter sp . strain HH1-1 were monitored during incubation at 25 degreesC, 5 degreesC, and after a 25 degreesC to 5 degreesC down shift in growth temperature . During growth at 25 degreesC, isocitrate lyase activity was detected in cell-free extracts, but at 5 degreesC and after cold shock, activity was measured primarily in the cell culture supernatant . Strain HH1-1 produced two cell-associated esterases and an extracellular esterase and lipase . Activities of the extracellular esterase and lipase were reduced when cells were grown at 5 degreesC and after cold shock . In contrast, an increased synthesis of a 53-kDa cell-associated esterase was observed 50 h after cold shock . An extracellular polysaccharide was also produced, indicated by a decrease in surface tension in cell culture supernatant when cells were incubated at 25 degreesC; but like extracellular enzyme activity, production of the exopolymer was reduced when cells were subjected to low temperatures . These results indicated that the intracellular enzyme, isocitrate lyase, leaked out of the cell after cold shock and during growth at 5 degreesC . The increased activity of a cell-associated esterase suggested this enzyme is required for growth at low temperatures . In contrast, activities of extracellular lipolytic enzymes and production of an extracellular polysaccharide were negatively affected at the lower temperatures.

J Protein Chem, 2000 Nov, 19(8), 709 - 16
Purification and catalytic properties of two catechol 1,2-dioxygenase isozymes from benzoate-grown cells of Acinetobacter radioresistens; Briganti F et al.; Two catechol 1,2-dioxygenase (C1,2O) isozymes (IsoA and IsoB) have been purified to homogeneity from a strain of Acinetobacter radioresistens grown on benzoate as the sole carbon and energy source . IsoA and IsoB are both homodimers composed of a single type of subunit with molecular mass of 38,600 and 37,700, Da respectively . In conditions of low ionic strength, IsoA can aggregate as a trimer, in contrast to IsoB, which maintains the dimeric structure, as also supported by the kinetic parameters (Hill numbers) . IsoA is identical to the enzyme previously purified from the same bacterium grown on phenol, whereas the IsoB is selectively expressed using benzoate as carbon source . This is the first evidence of the presence of differently expressed C1,2O isozymes in A . radioresistens or more generally of multiple C1,2O isozymes in benzoate-grown Acinetobacter cells . Purified IsoA and IsoB contain approximately 1 iron(III) ion per subunit and both show electronic absorbance and EPR features typical of Fe(III) intradiol dioxygenases . The kinetic properties of the two enzymes such as the specificities toward substituted catechols, the main catalytic parameters, and their behavior in the presence of different kind of inhibitors are, unexpectedly, very similar, in contrast to most of the previously known dioxygenase isozymes.

Microbiol Res, 2001 Mar, 155(4), 271 - 7
Detection and characterization of quorum sensing signal molecules in Acinetobacter strains; Gonzalez RH et al.; Quorum sensing is a widespread regulatory mechanism among Gram-negative bacteria . In this study, Acinetobacter strains were assayed for the presence of quorum sensing signal molecules capable of activating N-acylhomoserine lactone biosensors . By using an Agrobacterium tumefaciens reporter strain it was shown that all the cultures produced two to four detectable signal molecules with different chromatographic patterns . In A . calcoaceticus BD413 supernatants four compounds were detected in a time-dependent manner, and maximal activity was reached at stationary phase . The number of signal molecules was dependent on medium composition; typically, cultures in minimal medium displayed one or two more signals, as compared to complex medium . None of the Acinetobacter supematants showed autoinduction activity with an Chromobacterium violaceum reporter strain, neither in direct or competition assays.

Microbiol Res, 2001 Mar, 155(4), 263 - 9
Influence of iron on growth, production of siderophore compounds, membrane proteins, and lipase activity in Acinetobacter calcoaceticus BD 413; Nudel C et al.; Acinetobacter calcoaceticus BD413 was examined for production of siderophores and iron-repressible outer membrane proteins following growth in iron-restricted media . The iron-scavenging phenotype was associated with the secretion of iron-repressible catechol and the induction of a group of six outer membrane proteins with molecular weights ranging from 34 to 85 kDa . The amount of catechol produced was dependent on medium composition and iron stringency . The relation between iron limitation and lipase production was studied at the level of lipA transcription and extracellular lipase activity . In minimal medium, iron limitation slightly affected lipA expression but decreased exo-lipase activity significantly . However, if iron limitation and rich nitrogen sources were simultaneously present in the culture media, the production of lipase was increased approximately 4 times.

Crit Care Med, 2001 Apr, 29(4 Suppl), N114 - 20
Impact of antibiotic resistance on clinical outcomes and the cost of care; Niederman MS; Antibiotic-resistant organisms are common in intensive care unit infection and can be either Gram-positive or Gram-negative . A number of studies have evaluated whether these organisms can lead to excess morbidity, mortality, or cost . In general, the studies are confounded by a number of methodologic issues, including the selection of an appropriate control population . Cases and controls must be appropriately matched for the presence of infection, the presence of infection with similar organisms (but ones that are either antibiotic-sensitive or -resistant), and severity of illness . In addition, studies must account for the therapies given to patients who are infected with resistant organisms because resistance is an important risk factor for inadequate empirical therapy, and such therapy is itself a potent determinant of a number of adverse outcomes, including mortality . To date, the data with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus are inconsistent with regard to the effect on mortality rates, although infection with both organisms can lead to excess length of stay and increased cost of care . When studies have been adequately controlled and powered, infection with vancomycin-resistant enterococcus has had more of an effect on the mortality rate than infection with antibiotic-sensitive enterococci . Infection with resistant Gram-negatives also has adverse impact on outcome, with excess mortality being seen in patient groups infected with Acinetobacter and Pseudomonas aeruginosa . If we are to minimize the effect of resistance on medical outcomes and cost, it will be necessary to have a current knowledge of each intensive care unit's pathogens and susceptibility patterns, so that empirical therapy will have a good likelihood of being effective . In addition, new therapeutic agents may improve on the efficacy of older agents and could reduce cost if they allow for some patients to leave the hospital and to finish therapy with an oral formulation of a highly bioavailable agent.

Crit Care Med, 2001 Apr, 29(4 Suppl), N75 - 81
Increasing threat of Gram-negative bacteria; Waterer GW et al.; The widespread use of broad-spectrum antibiotics has led to emergence of antibiotic-resistant strains of many Gram-negative organisms . This problem is particularly serious in critically ill patients, especially those with ventilator-associated pneumonia . Extensive antibiotic resistance has developed in Gram-negative bacteria, due both to innate resistance in some species and the fact that they are highly adept at acquiring antibiotic-resistant determinants from each other . Antibiotic resistance develops through the following three basic mechanisms: alteration of the drug target, prevention of drug access to the target (including actively removing the drug from the bacteria), and drug inactivation . Certain Gram-negative microorganisms are particular problems in the intensive care unit, including Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia, and the Enterobacteriaceae . The combination of an increasing population at risk, and the natural virulence and adaptability of Gram-negative bacteria guarantees that critical care physicians will face a persistent and increasing challenge from these pathogens.

J Assoc Physicians India, 2001 Mar, 49, 324 - 6
Characterization of nonfermenters from clinical samples; Kharangate NV et al.; OBJECTIVE: Nonfermenters are a group of aerobic non sporing gram-negative bacilli found primarily free in nature and as commensals, whose pathogenic potentials are well established . The current study was conducted to assess the role of these nonfermenters in various infections and to characterize these isolates . METHODS: One hundred nonfermenters isolated from various clinical specimens were grouped according to Weaver-Hollis scheme based on growth on MacConkeys agar, oxidase activity and oxidation/fermentation of glucose . Species level identification was attempted based on a battery of biochemical tests . All isolates were then subjected to antimicrobial sensitivity . RESULTS: Majority of the isolates were encountered from pus and urine (50%) . These isolates belonged to six of the seven Weaver-Hollis groups . Fifty six per cent of the isolates belonged to genus Pseudomonas . Multidrug resistance with resistance to more than three antimicrobials was frequently seen . Amikacin and ciprofloxacin were found to be most effective . CONCLUSION: Nonfermenting gram negative organisms are responsible for variety of infective conditions . Amongst them genus Pseudomonas and Acinetobacter calcoaceticus were more frequently encountered . Amikacin or ciprofloxacin (for nonfermenters other than Pseudomonas) appears to be the drug of choice for treatment of such infections.

Clin Microbiol Infect, 2000 Dec, 6(12), 635 - 43
PCR-based DNA fingerprinting (REP-PCR, AP-PCR) and pulsed-field gel electrophoresis characterization of a nosocomial outbreak caused by imipenem- and meropenem-resistant Acinetobacter baumannii; Bou G et al.; OBJECTIVE: To demonstrate the usefulness of REP-PCR and AP-PCR on molecular typing of A . baumannii isolates . METHOD: From February to November 1997, 29 inpatients at Ramon y Cajal Hospital, Madrid-23 in five intensive care units (ICUs) and six at two different medical departments-were either colonized or infected with imipenem- and meropenem-resistant Acinetobacter baumannii (IMRAB) strains (MICs of 64-256 mg/L) . A wide antibiotic multiresistance profile was observed with IMRAB strains, and only tobramycin, sulbactam and colistin displayed valuable activity . For typing IMRAB isolates, repetitive extragenic palindromic sequence-based polymerase chain reaction (REP-PCR) and arbitrary primer sequence-based polymerase chain reaction (AP-PCR) methods were used and compared with pulsed-field gel electrophoresis (PFGE) as reference technique . For comparative purposes, 30 imipenem- and meropenem-susceptible A . baumannii (IMSAB) strains isolated before, during and after the outbreak were included in this study . RESULTS: The molecular typing results showed that the outbreak was caused by a single IMRAB strain (genotype 1) . On the other hand, seven different genotypes were observed in the pre-, at- and post-outbreak strains tested by REP-PCR . Regarding AP-PCR, three of four at-outbreak IMSAB strains were indistinguishable from the IMRAB profile . Thus, with AP-PCR, only six genotypes were obtained, apart from the IMRAB genotype . CONCLUSION: Under our experimental conditions, REP-PCR had a higher discriminatory power than AP-PCR, with PFGE as reference technique . The REP-PCR technique is a useful and expeditious method for the epidemiologic characterization of A . baumannii nosocomial outbreaks, the results being comparable to those obtained with the PFGE technique.

Appl Environ Microbiol, 2001 Apr, 67(4), 1675 - 81
Evaluation of inoculum addition to stimulate in situ bioremediation of oily-sludge-contaminated soil; Mishra S et al.; A full-scale study evaluating an inoculum addition to stimulate in situ bioremediation of oily-sludge-contaminated soil was conducted at an oil refinery where the indigenous population of hydrocarbon-degrading bacteria in the soil was very low (10(3) to 10(4) CFU/g of soil) . A feasibility study was conducted prior to the full-scale bioremediation study . In this feasibility study, out of six treatments, the application of a bacterial consortium and nutrients resulted in maximum biodegradation of total petroleum hydrocarbon (TPH) in 120 days . Therefore, this treatment was selected for the full-scale study . In the full-scale study, plots A and B were treated with a bacterial consortium and nutrients, which resulted in 92.0 and 89.7% removal of TPH, respectively, in 1 year, compared to 14.0% removal of TPH in the control plot C . In plot A, the alkane fraction of TPH was reduced by 94.2%, the aromatic fraction of TPH was reduced by 91.9%, and NSO (nitrogen-, sulfur-, and oxygen-containing compound) and asphaltene fractions of TPH were reduced by 85.2% in 1 year . Similarly, in plot B the degradation of alkane, aromatic, and NSO plus asphaltene fractions of TPH was 95.1, 94.8, and 63.5%, respectively, in 345 days . However, in plot C, removal of alkane (17.3%), aromatic (12.9%), and NSO plus asphaltene (5.8%) fractions was much less . The population of introduced Acinetobacter baumannii strains in plots A and B was stable even after 1 year . Physical and chemical properties of the soil at the bioremediation site improved significantly in 1 year.

Ann Acad Med Singapore, 2000 Nov, 29(6), 699 - 703
Evaluation of technetium-99m ciprofloxacin (Infecton) in the imaging of infection; Sundram FX et al.; INTRODUCTION: The aim of this study was to evaluate the usefulness of technetium-99m (Tc-99m) ciprofloxacin in imaging inflammation/infection . The ciprofloxacin for labelling, as a kit, was obtained from St Bartholomew's Hospital in London . MATERIALS AND METHODS: Patients were injected intravenously with Tc-99m ciprofloxacin and imaging was done at 10 minutes, 4 hours and 24 hours if necessary . Tomographic images (SPECT) were obtained in a few patients . Ninety-six patients were studied using Tc-99m ciprofloxacin . Forty-eight patients had bone scans and 22 had Tc-99m IgG scans . Eight patients were imaged using Tc-99m HMPAO labelled white blood cell, and bacteriological culture results were available in 24 patients . Organisms cultured included Acinetobacter baumanii, Streptococcus, Staphylococcus aureus, Pseudomonas, Klebsiella, Blastococidia, Methicillin-resistant S . aureus, Salmonella and Candida . RESULTS: Findings were evaluated against microbiology, alternative imaging modalities and clinical outcome . There were 47 true positives, 33 true negatives, 5 false positives and 11 false negatives, giving a sensitivity of 81% and specificity of 87% . The positive and negative predictive values were 90% and 75%, respectively . There were no side effects and the scan was particularly useful in the evaluation of painful joint prosthesis to exclude infection . Repeat studies on 8 patients given antibiotics over a long period were very useful in deciding on termination of the antibiotic treatment.

J Antimicrob Chemother, 2001 Apr, 47(4), 479 - 82
Sulbactam efficacy in experimental models caused by susceptible and intermediate Acinetobacter baumannii strains; Rodriguez-Hernandez MJ et al.; Sulbactam and imipenem were compared in an experimental pneumonia model in immunocompetent mice, using a susceptible strain of Acinetobacter baumannii, and in an experimental endocarditis model in rabbits, using an intermediately susceptible strain . In the former, sulbactam was as efficacious as imipenem in terms of survival, sterility of lungs and in the bacterial clearance from lungs and blood, provided that the t > MIC for sulbactam (1.84 h) was similar to that for imipenem (2.01 h) . In the endocarditis model, imipenem (t > MIC, 2.12 h) was more efficacious than sulbactam (t > MIC, 1.17 h) in bacterial clearance from vegetations . These results show the efficacy of sulbactam in infections caused by susceptible strains of A . baumannii, with an MIC up to 4 mg/L, provided that doses reach a t > MIC similar to that of imipenem . The activity of sulbactam was time dependent.

Kansenshogaku Zasshi, 2001 Feb, 75(2), 144 - 50
{Detection of gram-negative bacteria in patients and hospital environment at a room in geriatric wards under the infection control against MRSA}; Masaki H et al.; We prospectively surveyed gram-negative bacteria in patients and hospital environment in a room in the geriatric ward which was specifically under the infection control against MRSA once every two weeks between September and December 1996 . We investigated the inpatients in an 8-bed room in the geriatric wards (190 beds) of AINO Memorial Hospital, affiliated with Nagasaki University . During the study period, we performed a total of 431 cultures . The number of specimens cultured was 116 from airways (nose, 42; pharynx, 42; sputum, 32), 24 from decubitus ulcer, 40 from urine, 42 from feces, a total of 125 from skin (head, 42; forearm, 42; inguinal region, 41), and 84 from the hospital environment (floor swab, 42; settled agar plate, 42), respectively . A total of 15 species were isolated from the hospital environment . Some species were the same as those which were recovered from the hospital environment were those observed on each body site . In the hospital environment, the isolation rates of Acinetobacter baumanii and Klebsiella pneumoniae were significantly high in the settled agar plate (A . baumanii, p < 0.01; K . pneumoniae, p < 0.05, respectively) . Isolation rates of Pseudomonas aeruginosa, Citrobacter spp., and Enterobacter sakazakii were also high in the settled agar plate (p = 0.078, 0.078, 0.078, respectively) . In conclusion, gram-negative bacteria in patients may be associated with the environmental bacteria in the room in the geriatric wards.

Syst Appl Microbiol, 2000 Dec, 23(4), 599 - 606
Characterization of oxytetracycline-resistant heterotrophic bacteria originating from hospital and freshwater fishfarm environments in England and Ireland; Huys G et al.; This ecotaxonomic study compared the antibiotic tolerance among culturable oxytetracyline-resistant (Ot(r)) heterotrophic strains isolated from two aquatic environments representing human activities in health care and aquaculture, namely hospital effluents and freshwater fishfarms . Using a standardized methodology, samples taken in England and Ireland were analyzed to determine the antibiotic tolerance profiles of two groups of culturable Ot(r) bacterial isolates at the intergeneric and intrageneric level comprising heterotrophs (189 strains) and mesophilic Aeromonas spp . (153 strains), respectively . Antibiogram data of heterotrophic isolates revealed that Irish hospital strains comprised higher frequencies of multi-tolerance than those originating from fishfarm environments whereas a reverse correlation was found among the English heterotrophs . Polyphasic identification of the isolates using fatty acid analysis and API 20E profiling showed that this difference arose from the unique taxonomic diversity within each heterotrophic strain set . Acinetobacter (27%) and Brevundimonas (22%) were predominant among the Irish Ot(r) fishfarm isolates, whereas isolates originating from the English aquaculture site almost entirely consisted of Stenotrophomonas maltophilia (86%) exhibiting high frequencies of tolerance to ampicillin and streptomycin . Within both the English and the Irish Ot(r) Aeromonas strain sets, on the other hand, the hospital strain sets displayed higher numbers of multi-tolerant isolates than to fishfarm isolates although country-specific differences were observed for individual antimicrobial agents . The typical occurrence of kanamycin-tolerant aeromonads in the Irish hospital site could to some extent be linked to the typical presence of A . hydrophila DNA hybridization group (HG) 3 strains as determined by fatty acid analysis and fluorescent amplified fragment length polymorphism (FAFLP) fingerprinting . Essentially, these data indicate that tolerance profiles in a specific environment of one country do not necessarily reflect the corresponding tolerance profiles of the same type of environment in another country, and this mainly as a result of the unique taxonomic composition of each site . Ot(r) representatives of Acinetobacter, S . maltophilia, and A . veronii biovar sobria HG8 were common to most if not all of the four sites under study, indicating that these three taxa may serve as potential indicator organisms for monitoring antibiotic tolerance among indigenous bacterial populations in various aquatic environments.

Crit Care Med, 2001 Feb, 29(2), 304 - 9
Risk factors for nosocomial pneumonia in critically ill trauma patients; Tejada Artigas A et al.; OBJECTIVE: To determine risk factors for nosocomial pneumonia in critically ill trauma patients . DESIGN: Prospective cohort study . SETTING: The trauma intensive care unit (ICU) of a 1500-bed tertiary-care hospital . PATIENTS: All critically ill trauma patients (n = 103) admitted consecutively between November 1995 and October 1996 . INTERVENTIONS: A comparison of data recorded at the time of ICU admission and during the clinical evolution in patients with (n = 23) and without (n = 80) nosocomial pneumonia was made . Data referred mainly to possible risk factors were recorded; they also included factors related to pneumonia etiology and evolutive factors . Predictors of nosocomial pneumonia were assessed by logistic regression analysis . MEASUREMENTS AND MAIN RESULTS: The presence of significant growth on quantitative cultures of the protected specimen brush (> or = 103 colony forming units/mL) was required to accept pneumonia as microbiologically proven, as well as the concurrence of a cohort of clinical and radiologic signs . Twenty-three (22.3%) patients developed nosocomial pneumonia . The mean age of these patients was 41.7 yrs; 18 of them (78.3%) were men . The microorganisms isolated in significant concentrations were Acinetobacter baumanii (ten cases), Staphylococcus aureus (11 cases), Pseudomonas aeruginosa (five cases), Haemophilus influenzae (two cases), and Klebsiella pneumoniae, Citrobacter freundii, Serratia marcescens, Enterococcus spp., Enterobacter spp., coagulase-negative Staphylococcus, and Streptococcus intermedius (one case each one) . Risk factors for pneumonia by univariate analysis included nasogastric tube; continuous enteral feeding; prolonged mechanical ventilation (>1 day); use of H2-receptor antagonist, sucralfate, muscle relaxants, corticosteroids, barbiturates, and inotropic agents; positive end-expiratory pressure; intense sedation; re-intubation; tracheotomy; urgent brain computed tomography (CT) scan; craniotomy; iatrogenic event; and hyperventilation . The mortality rate was 43.5% (10 of 23) in the nosocomial pneumonia group and 18.8% in patients without nosocomial pneumonia (p =.02) . Also, the mean stay in the ICU, the therapeutic charge (measured with total and mean punctuation of the Therapeutic Intervention Scoring System) and the complications, infectious and noninfectious, of the clinical evolution were significantly more frequent in patients with nosocomial pneumonia than in those without pneumonia (p <.05) . In the multivariate analysis, continuous enteral feeding, craniotomy, prolonged mechanical ventilation (>24 hrs), use of positive end-expiratory pressure, and corticotherapy were independent predictors of nosocomial pneumonia . CONCLUSIONS: It seems that factors related to the patient's clinical course, rather than variables registered on the first days of ICU admission, are those that would exert an influence on the development of nosocomial pneumonia in critically ill trauma patients . In this way, from our point of view, in our study the main risk factors are the use of prolonged mechanical ventilation (>4 hrs) and positive end-expiratory pressure . At the same time, we can conclude that the reduction of this infection incidence could decrease the mean stay in the ICU, the therapeutic charge, and the prognosis in terms of mortality and morbidity.

Gene, 2001 Feb 7, 264(1), 77 - 85
Analysis of the pobA and pobR genes controlling expression of p-hydroxybenzoate hydroxylase in Azotobacter chroococcum; Quinn JA et al.; We report the cloning and analysis of a gene and its cognate regulatory element from a member of the Azotobacteriaceae which are involved in the breakdown of an aromatic compound . The genes from Azotobacter chroococcum encoding p-hydroxybenzoate hydroxylase (pobA) and its regulatory protein (pobR) were cloned from a genomic library and sequenced . Sequence analysis of pobA revealed homology with other bacterial p-hydroxybenzoate hydroxylase enzymes . Residues essential to the structure and function of the enzyme have been conserved . The pobR gene encodes a DNA binding regulatory protein with similarity to proteins from the AraC/XylS family of transcriptional activators . A fragment containing both pobA and pobR was cloned into pUC19 and p-hydroxybenzoate hydroxylase activity was induced in Escherichia coli by the addition of p-hydroxybenzoate . A frame-shift mutation introduced into the pobR gene prevented expression of p-hydroxybenzoate hydroxylase, indicating that PobR is the protein required for transcription of pobA . Interestingly, A . chroococcum PobR has no homology to the PobR protein that is the transcriptional activator of pobA in Acinetobacter strain ADP1, a protein that is homologous to the IclR family of transcriptional regulators . However, PobR from A . chroococcum is homologous to several other proteins, suggesting that these proteins will also function as transcriptional activators of pobA.

Cad Saude Publica, 2001 Jan-Feb, 17(1), 229 - 32
{Digestive tract microbiota in female Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) from colonies feeding on blood meal and sucrose plus blood meal}; Perira de Oliveira SM et al.; There are very few reports on the microbiota of the digestive tract of sand flies, an important omission considering that blood is not the only meal ingested . Male and female sand flies obtain sugar meals from several sources, thereby increasing their chance of infection with microorganisms . Chances of contamination are higher when insects are bred in the laboratory, and this may affect the development of Leishmania spp . From the digestive tract of 300 sand fly females separated in two groups we isolated 10 species of bacteria in group 1 and 8 species in group 2 . In group 1, Enterobacteriaceae of the following genera were identified: Serratia, Enterobacter, and Yokenella and the non-fermenters: Pseudomonas, Acinetobacter, and Stenotrophomonas . In group 2, the Enterobacteriaceae Enterobacter and Serratia were identified as well as the non-fermenters Acinetobacter, Stenotrophomonas, Burkolderia, and Pseudomonas.

Indian J Pediatr, 2001 Jan, 68(1), 15 - 9
Meropenem in neonatal severe infections due to multiresistant gram-negative bacteria; Koksal N et al.; Recently, new broad spectrum carbapenem has been investigated on a world-wide scale for the treatment of moderate to severe infections . In the neonatal intensive care units the extensive use of third generation cephalosporins for therapy of neonatal sepsis may lead to rapid emergence of multiresistant gram-negative organisms . We report the use of meropenem in 35 infants with severe infections due to Acinetobacter baumanii and Klebsiella pneumoniae . All gram negative bacteria were resistant to ampicillin, amoxicillin, ticarcilin, cefazoline, cefotaxime, ceftazidime, ceftriaxone and aminoglycosides . Eighty two percent of the cases (29/35) were born prematurely . Assisted ventilation was needed in 85.7% (30/35) . All infants deteriorated during their conventional treatment and were changed to meropenem monotherapy . Six percent (2/35) died . The incidence of drug-related adverse events (mostly a slight increase in liver enzymes) was 8.5% . No adverse effects such as diarrhea, vomiting, rash, glossitis, oral or diaper area moniliasis, thrombocytosis, thrombocytopenia, eosinophilia and seizures were observed . At the end of therapy, overall satisfactory clinical and bacterial response was obtained in 33/35 (94.3%) of the newborns treated with meropenem . Clinical and bacterial response rates for meropenem were 100% for sepsis and 87.5% for nosocomial pneumonia . This report suggests that meropenem may be a useful antimicrobial agent in neonatal infections caused by multiresistant gram negative bacilli . Further studies are needed to confirm these results: Meropenem, newborn, sepsis and nosocomial infection.

J Clin Microbiol, 2001 Mar, 39(3), 936 - 42
Diagnostics of neisseriaceae and moraxellaceae by ribosomal DNA sequencing: ribosomal differentiation of medical microorganisms; Harmsen D et al.; Fast and reliable identification of microbial isolates is a fundamental goal of clinical microbiology . However, in the case of some fastidious gram-negative bacterial species, classical phenotype identification based on either metabolic, enzymatic, or serological methods is difficult, time-consuming, and/or inadequate . 16S or 23S ribosomal DNA (rDNA) bacterial sequencing will most often result in accurate speciation of isolates . Therefore, the objective of this study was to find a hypervariable rDNA stretch, flanked by strongly conserved regions, which is suitable for molecular species identification of members of the Neisseriaceae and Moraxellaceae . The inter- and intrageneric relationships were investigated using comparative sequence analysis of PCR-amplified partial 16S and 23S rDNAs from a total of 94 strains . When compared to the type species of the genera Acinetobacter, Moraxella, and Neisseria, an average of 30 polymorphic positions was observed within the partial 16S rDNA investigated (corresponding to Escherichia coli positions 54 to 510) for each species and an average of 11 polymorphic positions was observed within the 202 nucleotides of the 23S rDNA gene (positions 1400 to 1600) . Neisseria macacae and Neisseria mucosa subsp . mucosa (ATCC 19696) had identical 16S and 23S rDNA sequences . Species clusters were heterogeneous in both genes in the case of Acinetobacter lwoffii, Moraxella lacunata, and N . mucosa . Neisseria meningitidis isolates failed to cluster only in the 23S rDNA subset . Our data showed that the 16S rDNA region is more suitable than the partial 23S rDNA for the molecular diagnosis of Neisseriaceae and Moraxellaceae and that a reference database should include more than one strain of each species . All sequence chromatograms and taxonomic and disease-related information are available as part of our ribosomal differentiation of medical microorganisms (RIDOM) web-based service . Users can submit a sequence and conduct a similarity search against the RIDOM reference database for microbial identification purposes.

Appl Environ Microbiol, 2001 Mar, 67(3), 1102 - 6
Emulsifying activities of purified Alasan proteins from Acinetobacter radioresistens KA53; Toren A et al.; The bioemulsifier of Acinetobacter radioresistens KA53, referred to as alasan, is a high-molecular-weight complex of polysaccharide and protein . The emulsifying activity of the purified polysaccharide (apo-alasan) is very low . Three of the alasan proteins were purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had apparent molecular masses of 16, 31, and 45 kDa . Emulsification assays using the isolated alasan proteins demonstrated that the active components of the alasan complex are the proteins . The 45-kDa protein had the highest specific emulsifying activity, 11% higher than the intact alasan complex . The 16- and 31-kDa proteins gave relatively low emulsifying activities, but they were significantly higher than that of apo-alasan . The addition of the purified 16- and 31-kDa proteins to the 45-kDa protein resulted in a 1.8-fold increase in the specific emulsifying activity and increased stability of the oil-in-water emulsion . Fast-performance liquid chromatography analysis indicated that the 45-kDa protein forms a dimer in nondenaturing conditions and interacts with the 16- and 31-kDa proteins to form a high-molecular-mass complex . The 45-kDa protein and the three-protein complex had substrate specificities for emulsification and a range of pH activities similar to that of alasan . The fact that the purified proteins are active emulsifiers should simplify structure-function studies and advance our understanding of their biological roles.

Indian J Med Sci, 2000 Mar, 54(3), 87 - 91
Prevalence of nonfermenters in clinical specimens; Vijaya D et al.; One hundred and thirty three non fermenting gram negative bacilli isolated out of 625 different clinical specimens were identified and characterised . Samples were exudate from chronic suppractive otits media (341), diabetic foot (117) wound (116) and blood (51) . Of these isolates Pseudomonas aeruginosa 105(78.94%) predominated followed by Acinetobacter sp 8 {6.1%}, Pseudomonas putrifaciens 6(4.5%), Flavobacterium sp 6(4.5%), Xanthomonas maltophilia 5(3.75%), Alkaligenes sp 3 (2.25) . 31 (23.30%) were resistant to commonly used antibiotics . Amikacin 85 (63.90%) was found to be more effective than fluoroquinolones (27.8-48.12%).

Anasthesiol Intensivmed Notfallmed Schmerzther, 2001 Jan, 36(1), 25 - 30
{Hygiene status of ambulances and equipment in rescue services}; Kober P et al.; PURPOSE: Focus on hygienic management in ambulances is presented based on findings from hygienic microbiological sampling . METHODS: In 44 ambulances, the handwashing area, equipment for artificial respiration, insufflation, intubation, aspiration, intravasal catheterisation, blood-pressure measurement, and sterile materials storage were examined hygienically and microbiologically using the following methods: water sampling, imprint technique, and swab technique with subsequent cultivation on blood-, endo-, and Sabouraud agar . RESULTS: The highest contamination was found in the hand-washing area and on insufflation equipment (up to > or = 100,000 cfu/ml), where proof of the potential pathogens Pseudomonas, Acinetobacter, and Alcaligenes spp . was found . The second highest contamination level was found on the sphygmomanometer cuffs, stethoscopes, and respirator masks (e.g., Enterococci and S . aureus were identified) . Apparently, the germs chiefly originate from the drinking water at the handwashing station, from the environment and mucous membranes from the skin, and intestines of the ambulance personnel . The predominant hygienic deficiensies were found in the equipment of the handwashing areas, and in the storage of resuscitation equipment and sterile materials . CONCLUSIONS: Based on the results of hygienic microbiological analysis, the main focus of hygienic measures--besides hand disinfection--should be on spray disinfection of the sphygmomanometer cuffs and stethoscopes as well as disinfection of ambulance equipment and storage areas for sterile devices, supplemented by dust protection of ready-to-use materials and devices . Stationary dispensers for hand disinfection possessing at least midlength levers must become the standard in ambulances, and conventional handwashing basins with plastic drinking-water containers and pump must be eliminated entirely.

Burns, 2001 Mar, 27(2), 140 - 4
Acinetobacter baumannii--an emerging nosocomial pathogen in the burns unit Manipal, India; Sengupta S et al.; A retrospective study on 113 patients admitted to the burns unit over a period of 12 months was undertaken to investigate the emerging trend of Acinetobacter baumannii infection . Wound infection with A . baumannii was seen in 13 (11.5%) patients . Of these six (46%) patients developed septicaemia with the same bacteria and five (38%) expired . The virulence of these bacteria, drug susceptibility pattern and its role as a nosocomial pathogen is discussed.

Burns, 2001 Mar, 27(2), 136 - 9
Microbiologic aspects of predominant bacteria isolated from the burn patients in Korea; Song W et al.; The risk of infection in burns is well-known . In recent decades, the antimicrobial resistance of bacteria isolated from burn patients has increased . For this reason, we have carried out a study of the predominant bacterial profiles and antimicrobial resistance patterns of isolates from a burn center in Korea . A retrospective study was undertaken at Hallym University, Hangang Sacred Heart Hospital to examine the bacterial isolates from the burn patients and to compare the antibiograms of the predominant bacteria isolated from these patients with those of the other wards over a period of 3 years . Pseudomonas aeruginosa was the most common (n=2997, 45.7%) isolate from the burn patients followed by Staphylococcus aureus (n=21261, 19.2%) and Acinetobacter baumannii (n=878, 13.4%) . These bacteria, isolated from the burn patients, were almost all higher in antimicrobial resistance rate than those in the non-burn patients (P<0.05) . Because these bacteria showed very high resistant rates, they must be avoided in order to control a hospital-acquired infection . Our results seem helpful in providing useful guidelines for choosing effective empiric antimicrobial therapy against bacteria isolated from the burn patients in Korea.

Semin Respir Infect, 2000 Dec, 15(4), 287 - 98
Problem pathogens (Pseudomonas aeruginosa and Acinetobacter); Chastre J et al.; A number of factors have been suspected of or identified as increasing the risk for pneumonia or colonization of the lower respiratory tract by Pseudomonas and/or Acinetobacter spp . in the intensive care unit (ICU), including advanced age, chronic lung disease, immunosuppression, surgery, use of antimicrobial agents, presence of such invasive devices as endotracheal and gastric tubes, and type of respiratory equipment . However, there is little doubt that of all these factors, extended ICU care because of severe underlying disease, prolonged respiratory therapy with mechanical ventilation, and prior antimicrobial therapy are the most important . Because the only factor amenable to prevention in this setting is antimicrobial therapy, avoiding unnecessary antibiotics should be a high priority in the management of such patients . Crude mortality rates of 30% to 75% have been reported for nosocomial pneumonia caused by Pseudomonas and/or Acinetobacter spp., with the highest rates reported in ventilator-dependent patients . It is therefore clear that the prognosis associated with this type of infection is considerably worse than that associated with infection caused by other gram-negative or gram-positive bacteria . Because bactericidal synergy against Pseudomonas and Acinetobacter spp . has been shown when carbenicillin and an aminoglycoside are combined, the use of an effective beta-lactam (piperacillin, ticarcillin, ceftazidime, or imipenem) and aminoglycoside combination remains the preferred therapeutic approach when possible . Future research efforts should also aim to improve our ability to diagnose and exclude infection in the ICU setting to avoid administering unnecessary antibiotics to patients without true pulmonary infection.

Pharmacotherapy, 2001 Feb, 21(2), 142 - 8
Epidemiology, resistance, and outcomes of Acinetobacter baumannii bacteremia treated with imipenem-cilastatin or ampicillin-sulbactam; Jellison TK et al.; STUDY OBJECTIVE: To evaluate epidemiology, resistance, and treatment outcomes of Acinetobacter baumannii bacteremia treated with imipenem-cilastatin or ampicillin-sulbactam for 72 hours or longer . DESIGN: Retrospective analysis . SETTING: University teaching hospital . PATIENTS: Forty-eight patients with A . baumannii bacteremia . INTERVENTION: Evaluation of susceptibility and clinical data from 48 patients treated with either ampicillin-sulbactam or imipenem-cilastatin from 1987-1999 . MEASUREMENTS and MAIN RESULTS: Comparing ampicillin-sulbactam and imipenem-cilastatin, there were no differences between days of bacteremia (4 vs 2 days, p=0.05), days to resolution of temperature or white blood cell count, success or failure during or at end of treatment, or intensive care unit total or antibiotic-related length of stay (13 vs 10 days, p=0.05) . Patients treated with ampicillin-sulbactam had significantly decreased antibiotic treatment costs (1500 dollars vs 500 dollars, p=0.004) . CONCLUSION: Ampicillin-sulbactam is at least as effective as imipenem-cilastatin based on clinical response at days 2, 7, and end of treatment and is a cost-effective alternative for treatment of A . baumannii infections.

Natl Med J India, 2000 Nov-Dec, 13(6), 296 - 300
Acinetobacter infection in neurosurgical intensive care patients; Suri A et al.; BACKGROUND: This study was performed to analyse the incidence of Acinetobacter infections in neurosurgical patients in the postoperative period . METHODS: Two thousand three hundred and twenty postoperative cranial neurosurgical intensive care unit (ICU) patients were studied from March 1995 to August 1996; 419 patients had a variety of infections and 42 patients had multiple infections . Acinetobacter was isolated in 103 patients (24.6% of total patients infected and 4.4% of total patients analysed) . Statistical analyses were performed to identify the risk factors, antibiotic sensitivity and outcome of therapy of Acinetobacter infection . RESULTS: Acinetobacter infection was not significantly related to the length of hospital stay prior to surgery but was related significantly to the length of stay in the ICU after surgery . Acinetobacter was isolated from sputum/tracheal secretions in 47/103 (45.6%), followed by cerebrospinal fluid {24/103 (23.3%)}, urine {15/103 (14.56%)} and blood {15/103 (11.65%)} . Acinetobacter infection was present in 54 (3.21%) of 1680 patients who had undergone routine/elective surgery and in 49 (7.66%) of 640 patients following emergency surgery . Elective/supportive ventilation for > 5 days, external ventricular cerebrospinal fluid drainage for > 5 days, intracranial pressure monitoring and prolonged indwelling Foley's urinary catheter during the perioperative period were independent risk factors (p < 0.005) . Acinetobacter isolated from sputum/tracheal secretions were mostly sensitive to amikacin, cefotaxime and ceftriaxone; while those grown from the cerebrospinal fluid were more often sensitive to ciprofloxacin, amikacin and netilmycin . Twenty-four patients succumbed to Acinetobacter infection; in 11 of these patients the organism was resistant to all antibiotics . CONCLUSION: Acinetobacter is an important nosocomial infection in neurosurgical intensive care patients.

Infect Control Hosp Epidemiol, 2001 Jan, 22(1), 48 - 9
A nosocomial outbreak of multiresistant Acinetobacter baumannii originating from an intensive care unit; Ling ML et al.; An outbreak of a multiresistant Acinetobacter baumannii in February through September 1996 affected 103 patients in a regional hospital in Singapore . We describe the effectiveness of closure of the outbreak area and the importance of good teamwork in the management of the outbreak.

Infect Control Hosp Epidemiol, 2001 Jan, 22(1), 35 - 40
An outbreak of imipenem-resistant Acinetobacter baumannii in critically ill surgical patients; Fierobe L et al.; OBJECTIVE: To describe an outbreak of imipenem-resistant Acinetobacter baumannii (IR-Ab) and the measures for its control, and to investigate risk factors for IR-Ab acquisition . DESIGN: An observational and a case-control study . SETTING: A surgical intensive care unit (ICU) in a university tertiary care hospital . METHODS: After admission to the ICU of an IR-Ab-positive patient, patients were prospectively screened for IR-Ab carriage upon admission and then once a week . Environmental cleaning and barrier safety measures were used for IR-Ab carriers . A case-control study was performed to identify factors associated with IR-Ab acquisition . Cases were patients who acquired IR-Ab . Controls were patients who were hospitalized in the ICU at the same time as cases and were exposed to IR-Ab for a similar duration as cases . The following variables were investigated as potential risk factors: baseline characteristics, scores for severity of illness and therapeutic intervention, presence and duration of invasive procedures, and antimicrobial administration . RESULTS: Beginning in May 1996, the outbreak involved 17 patients over 9 months, of whom 12 acquired IR-Ab (cases), 4 had IR-Ab isolates on admission to the ICU, and 1 could not be classified . Genotypic analysis identified two different IR-Ab isolates, responsible for three clusters . Ten of the 12 nosocomial cases developed infection . Control measures included reinforcement of barrier safety measures, limitation of the number of admissions, and thorough environmental cleaning . No new case was identified after January 1997 . Eleven of the 12 cases could be compared to 19 controls . After adjustment for severity of illness, a high individual therapeutic intervention score appeared to be a risk factor for IR-Ab acquisition . CONCLUSION: The outbreak ended after strict application of control measures . Our results suggest that high work load contributes to IR-Ab acquisition.

Vutr Boles, 2000, 32(1), 13 - 7
{A comparative study of antibacterial activity of ceftibuten, ceftazidime, cefuroxime and ampicillin against clinical isolates}; Ergova R et al.; Ceftibuten is an orally active third generation new cephalosporin . Its antibacterial activity in vitro was tested to many clinical isolates and was compared to the activity of ceftazidime, cefuroxime and ampicillin, by twofold serial dilution method in Muller-Hinton agar--detection of minimum inhibitory concentrations (MIC) and by the disc-diffusion method of Kirby-Bauer . The new cephalosporin demonstrated great activity against the different clinical important strains . Many resistant strains to ampicillin were high susceptible to ceftibuten . The majority of Gram-negative organisms, including Enterobacteriaceae, the respiratory pathogens M.(B.) catarrhalis and H . influenzae are highly susceptible to Ceftibuten, however Pseudomonas, Acinetobacter are resistant . The majority of methicillin-susceptible strains of Staphylococcus are resistant too . New cephallosporin was also active against S . pyogenes (Streptococcus gr . A) and penicillin-susceptible pneumococci, but was inactive against S . agalactiae (Streptococcus gr . B), S . pneumoniae penicillin-resistant strains and enterococci, similar to the other cephalosporins . The activity of ceftibuten was higher than that of ampicillin and cefuroxime against beta-lactamases positive strains of H . influenzae and M.(B) catarrhalis, also against tested strains of Enterobacteriaceae . The major priority of the new antibacterial agent over other cephalosporins and ampicillin is its stability to hydrolysis by the main broad-spectrum beta-lactamases producing E . coli and K . pneumoniae sp.

J Burn Care Rehabil, 2000 Nov-Dec, 21(6), 523 - 7
A survey of gram-negative bacteria survival on hospital fabrics and plastics; Neely AN; One critical factor for the transmission of microorganisms from person to person or from the environment to a person (patient or health care worker) is the ability of the microbe to survive on an environmental surface . The purpose of this study was to determine the length of survival of various gram-negative bacteria on fabrics and plastics commonly used in hospitals . Seven materials were tested: smooth cotton (clothing), cotton terry (towels), 60% cotton-40% polyester blend (scrub suits and lab coats), polyester (drapes), 75% nylon-25% spandex (pressure garments), polyvinyl (splash aprons), and polyurethane (keyboard covers) . The following bacteria were tested: Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Proteus mirabilis, Acinetobacter species, and Enterobacter species . Swatches of the materials were inoculated with defined amounts of bacteria and assayed at regular intervals . Survival was dependent on the bacterium, its inoculum size, and the material tested . At 102 microorganisms per swatch, bacteria survived from less than 1 hour to 8 days . At 10(4) to 10(5) bacteria per swatch, survival ranged from 2 hours to more than 60 days . These findings emphasize the need for careful disinfection and conscientious contact control procedures in areas that serve immunosuppressed individuals, such as patients with burn injuries.

J Med Microbiol, 2001 Jan, 50(1), 71 - 7
Carriage of class 1 integrons and antibiotic resistance in clinical isolates of Acinetobacter baumannii from northern Spain; Gallego L et al.; A collection of 70 clinical isolates of Acinetobacter baumannii from Bilbao in northern Spain was examined by PCR for the presence of class 1 integron structures . The organisms comprised 21 distinct RAPD genotypes, with 10 distinct antibiogram patterns . Four different integron structures were detected in a total of 59 (84%) of the 70 isolates, with two predominant integron structures found in 20 and 30 isolates each . No clear antibiogram differences could be correlated with the presence or absence of integron structures, but sequence analysis of two of the internal integron regions indicated homology with genes encoding ANT(2'') adenyltransferase activity and AAC(6')-Ib acetyltransferase activity . Phenotypic analysis of aminoglycoside resistance profiles indicated that many isolates produced a combination of aminoglycoside-modifying enzymes, with most of the observed resistance to amikacin being associated with a gene encoding APH(3')-VI phosphotransferase, as detected by PCR . RAPD analysis indicated that all the Bilbao isolates producing APH(3')-VI were distinct from an epidemic integron-carrying and APH(3')-VI-producing Acinetobacter strain found in other regions of Spain . It is concluded that, although class 1 integrons are widely disseminated amongst clinical isolates of A . baumannii from the Bilbao region of Spain, at present they are not playing a major role in the dissemination of antibiotic resistance genes in this region.

Arzneimittelforschung, 2000 Dec, 50(12), 1134 - 7
Lipase activity of Acinetobacter baumannii after treatment with meropenem; Hostacka A; The effects of meropenem (CAS 96036-03-2) at subinhibitory concentrations (sub-MICs; 1/4, 1/8 or 1/16 of the minimal inhibitory concentrations) on the lipase activity of 15 strains of Acinetobacter baumannii were evaluated in vitro . The lipolytic activity was demonstrated by hydrolysis of the substrate Tween 20 . Meropenem at the concentrations tested affected the production of bacterial lipase . The degree of induced changes was strain and antibiotic concentration dependent . Eight strains showed an increased lipolytic activity after treatment with meropenem at all three sub-MICs tested; four strains after exposure to two concentrations, and two strains after the treatment with meropenem at one of the concentrations tested . Meropenem at all concentrations reduced the lipase activity only in one strain . In six strains the enzyme activity was decreased only after treatment with some antibiotic concentrations . The possible relevance of increased lipolytic activity in most A . baumannii strains after the effect with meropenem at subinhibitory concentrations has to be clarified by additional studies.

Tunis Med, 2000 Aug-Sep, 78(8-9), 480 - 3
{Ecological aspects and prophylaxis of Acinetobacter baumannii nosocomial infection}; Boukadida J; Acinetobacter Baumannii is an aerobic strit gram negative bacteria cause of epidemic infection in intensive care units this bacteria is isolated from the patient and its environment . The detection of AB infection require the isolation of patients and decontamination of the material despite the virulence of the germ, these measures are necessary due to the rapid extension of epidemic in the absence of adequate means.

Schweiz Med Wochenschr, 2000 Dec 16, 130(50), 1930 - 6
{Problems of antibiotic-resistance Gram negative pathogens in the hospital environment}; Liassine N; Gram-negative pathogens in the hospital environment belong to such distinct families as Enterobacteriaceae, Pseudomonas, Acinetobacter and Stenotrophomonas . They differ in virulence but all present natural (or intrinsic) resistance and the capacity to develop rapidly acquired resistance, the main factor in their selection in the hospital environment . Dissemination of resistance is due either to dissemination of a clonal strain or dissemination of the gene of resistance amongst bacteria belonging to unrelated species . In medical practice, the development of resistance poses various problems: a therapeutic problem for the physician who must prescribe an active antibiotic that does not select resistant mutants; a microbiological problem in relation to the difficulty of detecting particular resistances such as the production of extended spectrum beta-lactamase; a problem for the infection control team whose task is to limit the dissemination of multi-resistant bacteria . Against the complexity and efficacy of bacterial resistance strategies against antimicrobial agents, the combined competences of clinicians, microbiologists and the infection control team are needed.

Epidemiol Mikrobiol Imunol, 2000 Nov, 49(4), 174 - 7
{New findings on the genus Acinetobacter}; Hostacka A; The author reviewed recent data on the genus Acinetobacter . It is an evaluation of their participation in nosocomial infections, antibiotic resistance, virulence factors as well as the possibilities of modifications of their virulence after treatment with antibiotics.

J Bacteriol, 2001 Feb, 183(3), 873 - 81
Effects exerted by transcriptional regulator PcaU from Acinetobacter sp . strain ADP1; Trautwein G et al.; Protocatechuate degradation is accomplished in a multistep inducible catabolic pathway in Acinetobacter sp . strain ADP1 . The induction is brought about by the transcriptional regulator PcaU in concert with the inducer protocatechuate . PcaU, a member of the new IclR family of transcriptional regulators, was shown to play a role in the activation of transcription at the promoter for the structural pca genes, leaving open the participation of additional activators . In this work we show that there is no PcaU-independent transcriptional activation at the pca gene promoter . The minimal inducer concentration leading to an induction response is 10(-5) M protocatechuate . The extent of expression of the pca genes was observed to depend on the nature of the inducing carbon source, and this is assumed to be caused by different internal levels of protocatechuate in the cells . The basal level of expression was shown to be comparatively high and to vary depending on the noninducing carbon source independent of PcaU . In addition to the activating function, in vivo results suggest a repressing function for PcaU at the pca gene promoter in the absence of an elevated inducer concentration . Expression at the pcaU gene promoter is independent of the growth condition but is subject to strong negative autoregulation . We propose a model in which PcaU exerts a repressor function both at its own promoter and at the structural gene promoter and in addition functions as an activator of transcription at the structural gene promoter at elevated inducer concentration.

Med Sci Monit, 2000 Jan-Feb, 6(1), 50 - 4
Cerebrospinal meningitis with the presence of Acinetobacter spp; Gospodarek E et al.; The study was conducted on 16 strains of Acinetobacter sp . which were isolated from cerebrospinal fluid . The diagnostic material was analysed with the use of automatic BacT/Alert system (Organon Teknika) . The analysis was performed in the Department of Microbiology, Medical University in Bydgoszcz . API 20NE system (bioMerieux) enabled the identification of 14 strains (87.5%) as A . baumannii, 1 strain as A . haemolyticus and 1 strain as A . lwoffii . The micro-organisms were isolated from patients whose age ranged between 4 and 66 years . These patients were treated in the departments of Neurosurgery (75.0%), Neurology (18.8%) and Intensive Therapy (6.2%) . The infection of cerebrospinal fluid was caused by injury and subsequent exposure to the bacteria present in external environment . Antibiotic-sensitivity of these micro-organisms was evaluated with the help of disc-diffusion method, observing standardisation conditions outlined by NCCLS . All the strains proved sensitive to carbapenems, 15 strains were sensitive to netilmicin, 7 strains--to tobramycin and 7 strains--to amikacin . All the strains displayed multiple resistance . The only exception was A . haemolyticus . The use of two-discs allowed for the detection of ESBLs in 7 A . baumannii strains . Positive results were most frequently obtained after the combination of sublactam and aztreonam . Due to microscopic resemblance between Acinetobacter spp., and bacteria of Neisseria, Moraxella and Haemophilus genus, microbiological diagnostics should not be restricted to microscopic assessment of cerebrospinal fluid and quick serological tests evaluating the antigens of the most frequent aetiological factors . Considering multiple resistance of Acinetobacter spp . to antibiotics, the treatment should be based on sensitivity tests and the ability of a given antibiotic to penetrate into cerebrospinal fluid . In our opinion, both reasonable antibiotic policy as well as observing the principles of hygiene and monitoring infections play equally important roles in the prevention of infections with Acinetobacter spp . Such combined measures may help to prevent the spreading of multiple resistant strains in hospital environment.

Environ Microbiol, 1999 Aug, 1(4), 307 - 17
Molecular screening for alkane hydroxylase genes in Gram-negative and Gram-positive strains; Smits TH et al.; We have developed highly degenerate oligonucleotides for polymerase chain reaction (PCR) amplification of genes related to the Pseudomonas oleovorans GPo1 and Acinetobacter sp . ADP1 alkane hydroxylases, based on a number of highly conserved sequence motifs . In all Gram-negative and in two out of three Gram-positive strains able to grow on medium- (C6-C11) or long-chain n-alkanes (C12-C16), PCR products of the expected size were obtained . The PCR fragments were cloned and sequenced and found to encode peptides with 43.2-93.8% sequence identity to the corresponding fragment of the P . oleovorans GPo1 alkane hydroxylase . Strains that were unable to grow on n-alkanes did not yield PCR products with homology to alkane hydroxylase genes . The alkane hydroxylase genes of Acinetobacter calcoaceticus EB104 and Pseudomonas putida P1 were cloned using the PCR products as probes . The two genes allow an alkane hydroxylase-negative mutant of Acinetobacter sp . ADP1 and an Escherichia coli recombinant containing all P . oleovorans alk genes except alkB, respectively, to grow on n-alkanes, showing that the cloned genes do indeed encode alkane hydroxylases.

Environ Microbiol, 1999 Jun, 1(3), 259 - 71
rRNA probe-based cell fishing of bacteria; Stoffels M et al.; We have developed a new, cultivation-independent, fast and flexible method for the rRNA-targeted probe-based enrichment of bacteria . The target cells were labelled by in situ hybridization with biotinylated polyribonucleotide probes . These probes were generated by in vitro transcription of amplified rDNA of a variable region in domain III of the 23S rRNA molecules . The probes were about 300 nucleotides in length and were labelled by incorporation of biotin-UTP during the transcription . Probes were hybridized with bacterial cells and incubated with paramagnetic streptavidin-coated particles . The labelled target cells can be separated in a column filled with steel wool inserted into the field of a permanent magnet . Unlabelled, non-target cells pass through the column, whereas labelled cells are retained . They were eluted from the column after removal of the magnetic field . Up to now, the method has been tested with mixtures of different pure cultures . For the first time, transcript probes have been used for the labelling of the target cells and for their specific separation . The enrichment of the target cells can be monitored by a streptavidin-fluorescein staining of the biotinylated target cells and/or by a subsequent in situ hybridization with fluorescently labelled oligonucleotide probes . Enrichment rates of up to 90-fold, depending on the original abundance of the cells of interest, could be determined . To demonstrate that the sorted cells were amenable to molecular analysis, we amplified and sequenced a part of the tuf gene of enriched Acinetobacter calcoaceticus cells.

Antimicrob Agents Chemother, 2001 Mar, 45(3), 710 - 4
IMP-4, a novel metallo-beta-lactamase from nosocomial Acinetobacter spp . collected in Hong Kong between 1994 and 1998; Chu YW et al.; Between 1994 and 1998, 97 imipenem-resistant Acinetobacter isolates were identified at the Prince of Wales Hospital, Hong Kong, China . A bla(IMP) PCR product was obtained from 23 of 35 viable cultures; 12 isolates belonged to genomic DNA group 3, 8 belonged to group 2 (Acinetobacter baumannii), 2 belonged to group 13TU, and 1 belonged to group 1 . The bla(IMP) homologues were sequenced from two isolates from genomic DNA group 2 and one isolate each from groups 3 and 13TU . The four sequences included an identical 738-bp open reading frame, predicted to encode a polypeptide of 246 amino acids, with 95.6% homology to IMP-1 and 89.3% homology to IMP-2 . The new enzyme, designated IMP-4, was partially purified . It had a pI of 8.0 and was strongly active against imipenem and meropenem, with V(max) values 53 and 8% of that for penicillin G, respectively . Strong activity was also seen against oxyimino-aminothiazolyl cephalosporins but not against aztreonam . Hydrolytic activity was inhibited by EDTA but not by clavulanate or tazobactam . Carbapenem MICs for most bla(IMP)-positive isolates were 4 to 32 microg/ml, but one isolate with the intact gene was susceptible, with imipenem and meropenem MICs of 0.25 and 0.5 microg/ml, respectively . The latter isolate did not produce the band with a pI of 8.0, and gene expression was inferred to have been lost . None of the isolates studied in detail contained extrachromosomal DNA, and carbapenem resistance was not transmissible to Escherichia coli . Nevertheless, the presence of bla(IMP-4) in different genomic DNA groups implies horizontal transfer, and sequences resembling a GTTRRRY integrase-dependent recombination motif were identified in the flanking regions of bla(IMP-4).

FEMS Microbiol Lett, 2001 Feb 20, 195(2), 211 - 5
The natural transformation of the soil bacteria Pseudomonas stutzeri and Acinetobacter sp . by transgenic plant DNA strictly depends on homologous sequences in the recipient cells; de Vries J et al.; The nptII(+) gene present in the genome of transgenic potato plants transforms naturally competent cells of the soil bacteria Pseudomonas stutzeri and Acinetobacter BD413 (both harboring a plasmid with an nptII gene containing a small deletion) with the same high efficiency as nptII(+) genes on plasmid DNA (3x10(-5)-1x10(-4) transformants per nptII(+)) despite the presence of a more than 10(6)-fold excess of plant DNA . However, in the absence of homologous sequences in the recipient cells the transformation by nptII(+) dropped by at least about 10(8)-fold in P . stutzeri and 10(9)-fold in Acinetobacter resulting in the latter strain in < or =1x10(-13) transformants per nptII(+) . This indicated a very low probability of non-homologous DNA fragments to be integrated by illegitimate recombination events during transformation.

Chest, 2001 Feb, 119(2 Suppl), 397S - 404S
Resistance patterns among nosocomial pathogens: trends over the past few years; Jones RN; Multiple surveillance studies have demonstrated that resistance among prevalent pathogens is increasing at an alarming rate, leading to greater patient morbidity and mortality from nosocomial infections . Among Gram-positive organisms, the most important resistant pathogens are methicillin- (oxacillin-)resistant Staphylococcus aureus, beta-lactam-resistant and multidrug-resistant pneumococci, and vancomycin-resistant enterococci . Important causes of Gram-negative resistance include extended-spectrum beta-lactamases (ESBLs) in Klebsiella pneumoniae, Escherichia coli, and Proteus mirabilis, high-level third-generation cephalosporin (Amp C) beta-lactamase resistance among Enterobacter species and Citrobacter freundii, and multidrug-resistance genes observed in Pseudomonas aeruginosa, Acinetobacter, and Stenotrophomonas maltophilia . In selecting an empiric treatment for a nosocomial infection, one should consider the prevalent resistance patterns . Antimicrobials used for the treatment of nosocomial infections should be effective against any likely resistant pathogens and should not further promote the development of resistance . Recent data suggest that because of ESBLs and high-level amp C beta-lactamase resistances, use of third-generation cephalosporins may be ineffective in many patients with nosocomial infections . In addition, use of these agents may allow overgrowth of inherently resistant enterococci . The role of fluoroquinolones in the empiric treatment of nosocomial infections is also being limited by new resistance patterns and increasing resistance levels . Available antimicrobials with good activity against many resistant pathogens include the carbapenems, piperacillin/tazobactam, and cefepime . In addition, several new agents with good activity against Gram-positive organisms are in development or have been recently released . Appropriate antimicrobial selection, surveillance systems, and effective infection-control procedures are key partners in limiting antimicrobial-resistant pathogen occurrence and spread.

Chest, 2001 Feb, 119(2 Suppl), 373S - 384S
Hospital-acquired pneumonia: risk factors, microbiology, and treatment; Lynch JP 3rd; Pneumonia complicates hospitalization in 0.5 to 2.0% of patients and is associated with considerable morbidity and mortality . Risk factors for hospital-acquired pneumonia (HAP) include mechanical ventilation for > 48 h, residence in an ICU, duration of ICU or hospital stay, severity of underlying illness, and presence of comorbidities . Pseudomonas aeruginosa, Staphylococcus aureus, and Enterobacter are the most common causes of HAP . Nearly half of HAP cases are polymicrobial . In patients receiving mechanical ventilation, P aeruginosa, Acinetobacter, methicillin-resistant S aureus, and other antibiotic-resistant bacteria assume increasing importance . Optimal therapy for HAP should take into account severity of illness, demographics, specific pathogens involved, and risk factors for antimicrobial resistance . When P aeruginosa is implicated, monotherapy, even with broad-spectrum antibiotics, is associated with rapid evolution of resistance and a high rate of clinical failures . For pseudomonal HAP, we advise combination therapy with an antipseudomonal beta-lactam plus an aminoglycoside or a fluoroquinolone (eg, ciprofloxacin).

J Hosp Infect, 2001 Feb, 47(2), 159 - 62
Typing of Acinetobacter baumannii isolated from hospital-acquired respiratory infections in a tertiary care centre in southern India; Mathai E et al.; In an attempt to define the epidemiology of Acinetobacter baumannii infection, 27 isolates, obtained from hospital-acquired respiratory infections, were typed using random amplified polymorphic DNA (RAPD) profile and antimicrobial susceptibility patterns . Ten different patterns were obtained with ERIC2 primer: 14 isolates had a similar profile representing a single strain . Within RAPD types, isolates could be further classified based on their antibiogram; however, strains of different types had similar antibiograms . This study showed that many different genetic types of A . baumannii are prevalent in our hospital . While antibiograms alone are not sufficiently discriminatory, RAPD typing helps in identifying outbreaks and in assessing infection control procedures within a hospital .

Oral Microbiol Immunol, 2001 Feb, 16(1), 1 - 9
Oral colonization of aerobic and facultatively anaerobic gram-negative rods and cocci in irradiated, dentate, xerostomic individuals; Leung WK et al.; This study aimed at investigating the oral colonization of aerobic and facultatively anaerobic gram-negative rods and cocci in head- and neck-irradiated, dentate, xerostomic individuals . Subjects were recruited from a nasopharyngeal carcinoma clinic and were segregated into group A: <60 years (n=25, 48+/-6 years, 5+/-5 years post-irradiation) and group B: >or=60 years (n=8, 67+/-4 years, 2+/-2 years post-irradiation) and were compared with age- and sex-matched normal individuals, group C: <60 years (n=20, 44+/-12 years) and group D: >or=60 years (n=10, 70+/-3 years) . Selective culture of the oral rinse samples was carried out to isolate, quantify and speciate (using API 20E kit) aerobic and facultatively anaerobic gram-negative rods and cocci recovery . All test subjects were put under comprehensive oral and preventive care for 3 months, and 12 group A and 5 group B subjects were recalled for reassessment of aerobic and facultatively anaerobic gram-negative rods and cocci colonization . All identical isolates, pre- and post-hygienic care, were phenotypically (Vitek, Hazelwood, MA and antibiogram profile) and genotypically (pulsed-field gel electrophoresis) evaluated . The aerobic and facultatively anaerobic gram-negative rods and cocci isolated from the first round oral rinse samples included: Acinetobacter, Neisseria, Chryseomonas, Flavimonas, Pseudomonas, Citrobacter, Enterobacter, Escherichia, Klebsiella, Flavobacterium and Weeksella species . The aerobic and facultatively anaerobic gram-negative rods and cocci isolation rate was high for irradiated individuals, and they were 64/25% and 100/80% for groups A/C and B/D, respectively . Recovery of aerobic and facultatively anaerobic gram-negative rods and cocci and Klebsiella pneumoniae subsp . pneumoniae in oral rinse samples were found to be significantly more prevalent in the irradiated subjects (groups A and B) . Enterobacteriaceae were more frequently isolated from oral rinse samples of aged irradiated subjects (group B vs D, P<0.05), where the quantity of Citrobacter freundii (colony-forming units/ml oral rinse) was also significantly elevated . The isolation rate of aerobic and facultatively anaerobic gram-negative rods and cocci after hygienic care remained unchanged; 3 of 12 and 3 of 5 of the recalled subjects from groups A and B, respectively, harbored same aerobic and facultatively anaerobic gram-negative rods and cocci species . However, only two pairs of K . pneumoniae subsp . pneumoniae, sequentially isolated from same patients in group B, were found to be identical by pulsed-field gel electrophoresis . This may be due to reinfection of the microbes from the same source or permanent colonization . In conclusion, irradiation-induced xerostomia seems to favor frequent, repeated, transient intraoral colonization of aerobic and facultatively anaerobic gram-negative rods and cocci.

Enzyme Microb Technol, 2001 Feb 1, 28(2-3), 265 - 274
Large scale production of cyclohexanone monooxygenase from Escherichia coli TOP10 pQR239; Doig SD et al.; The cyclohexanone monooxygenase (CHMO) from Acinetobacter calcoaceticus NCIMB 9871 has been cloned into Escherichia coli in an L-arabinose inducible vector . The recombinant E . coli containing the L-arabinose inducible CHMO was grown at 1.5 litres under controlled conditions to determine the parameters for growth and induction . It was found that induction with 0.1% (w/v) L-arabinose at late logarithmic phase of growth and growth for a further 2.5 to 3 h gave the optimal CHMO titre ( approximately 3500 U.l(-1,) 630 U . g dry cell weight(-1)) . High dissolved oxygen concentrations were shown to be deleterious to the CHMO titre . This influenced the strategy for growth and induction, and was optimal when the oxygen uptake rate was maximized but the dissolved oxygen concentration was zero . Finally, a 300 litre scale fermentation was carried out giving a total CHMO titre of >8 x 10(5) U.

Int J Pediatr Otorhinolaryngol, 2001 Jan, 57(1), 1 - 9
Acute mastoiditis--the antibiotic era: a multicenter study; Luntz M et al.; OBJECTIVES: To evaluate the clinical course and identify the causative organisms of acute mastoiditis in a community where most of the patients who develop acute otitis media are treated with antibiotics . METHODS: A multicenter retrospective review of a series of 223 consecutive cases of acute mastoiditis . SETTING: Nine secondary or tertiary academic or non-academic referral centers . RESULTS: Prior to the diagnosis of acute mastoiditis, 121 of the patients (54.3%) had been receiving oral antibiotic treatment for acute otitis media for periods ranging from 1 to 21 days (mean 5.3 days) . Samples for bacterial culture were obtained from 152 patients . Cultures were negative in 60 patients . The organisms isolated in the 92 positive cultures were: Streptococcus pneumoniae (15 patients), Streptococcus pyogenes (14 patients), Staphylococcus aureus (13 patients), Staphylococcus coagulase negative (three patients), Pseudomonas aeruginosa (eight patients), Haemophilus influenzae (four patients), Proteus mirabilis (two patients), Escherichia coli (two patients), Klebsiella pneumoniae (one patient), Enterobacter (one patient), Acinetobacter (one patient), anaerobic gram-negative bacilli (one patient), and fungi (two patients) . Ten patients had mixed flora . Sixteen patients presented with complications (cerebellar abscess, perisinus empyema, subdural abscess or empyema, extradural abscess, cavernous sinus thrombosis, lateral sinus thrombosis, bacterial meningitis, labyrinthitis, petrositis, or facial nerve palsy) . CONCLUSIONS: Antibiotic treatment cannot be considered an absolute safeguard against the development of acute mastoiditis . Early myringotomy for acute otitis media seems to decrease the incidence of complications . The distribution of causative organisms in acute mastoiditis differs from that in acute otitis media . Intracranial complications in acute mastoiditis are not rare . Because of the diversity of causative organisms in acute mastoiditis and the growing resistance of bacteria to the various antibiotics, all means to obtain a sample for culture prior to antibiotic treatment, including general anesthesia.

Int J Antimicrob Agents, 2001 Feb, 17(2), 147 - 50
Nosocomial pneumonia: importance of recognition of aetiological agents to define an appropriate initial empirical therapy; Costa SF et al.; Of the 16,024 patients hospitalized from January 1995 to October 1997, 397 (2.4%) acquired nosocomial pneumonia and the aetiological agent was defined in 101 (25%) . About 82% developed late onset pneumonia (>7 days of hospitalization) . The site of isolation of microorganisms was bronchoalveolar lavage (BAL) (49%), blood culture (39%), pleural effusion (10%) and (2%) pulmonary tissue . Gram-negative bacteria were responsible for 54% of infections . Staphylococcus aureus (34%) was the most frequent microorganism isolated followed by Acinetobacter baumannii (29%) and Pseudomonas aeruginosa and Klebsiella pneumoniae, responsible for 7% of nosocomial pneumonia . Monotherapy gave good cover for early onset pneumonia, but not for late onset pneumonia . Based on our selection criteria, ciprofloxacin was the best monotherapy for early (50%) and late (31%) onset pneumonia . Vancomycin plus ciprofloxacin gave cover of 85% of early and 64% of late onset pneumonia . Monotherapy with ciprofloxacin and also combination therapy of ciprofloxacin plus vancomycin may be good options as initial empirical therapy for nosocomial pneumonia.

Int J Antimicrob Agents, 2001 Feb, 17(2), 143 - 6
The in vitro activity of sulbactam combined with third generation cephalosporins against third generation cephalosporin-resistant bacteria; Zhang YL et al.; The in vitro activity of the beta-lactamase inhibitor sulbactam combined with cefuroxime, cefotaxime or ceftazidime in the ratio of 1:1 was studied against ceftazidime- or cefuroxime-resistant Gram-negative rods and Staphylococcus aureus . Sulbactam enhanced the antibacterial activities of cefuroxime, cefotaxime and ceftazidime against Gram-negative rods . The MIC(90) of ceftazidime against Escherichia coli, Enterobacter cloacae, Citrobacter freundii, Acinetobacter spp . and Pseudomonas aeruginosa was reduced 4-fold and that of cefotaxime against E . coli, E . cloacae, C . freundii and Acinetobacter spp . reduced by 2-4-fold . However, sulbactam did not enhance the activities of cefuroxime, cefotaxime or ceftazidime against S . aureus, enterococci and Stenotrophomonas maltophilia . With the combination of sulbactam and ceftazidime at the ratio of 1:1, 38.4% of E . coli, 45.3% of E . cloacae, 66.6% of C . freundii and 60% of Acinetobacter spp . initially resistant to ceftazidime became susceptible.

Protein Expr Purif, 2001 Feb, 21(1), 81 - 6
Purification and characterization of hexahistidine-tagged cyclohexanone monooxygenase expressed in Saccharomyces cerevisiae and Escherichia coli; Cheesman MJ et al.; Cyclohexanone monooxygenase (CMO) is a soluble flavoenzyme originally isolated from Acinetobacter spp . which carries out Baeyer-Villiger reactions with cyclic ketone substrates . In the present study we cloned the Acinetobacter CMO gene and modified it for facile purification from heterologous expression systems by incorporation of a His(6)-tag at its C-terminus . A single purification step employing metal (Ni(2+))-affinity column chromatography provided essentially homogeneous enzyme in yields of 69-72% . The properties of the purified, recombinant enzymes (rCMO) were compared with that of native CMO (nCMO) isolated from Acinetobacter cultures grown in the presence of cyclohexanone . The specific activities of His(6)-tagged rCMO and nCMO toward their index substrate, cyclohexanone, were similar and ranged from 14 to 20 micromol/min/mg . nCMO and rCMO from the Escherichia coli expression system exhibited molecular masses, determined by electrospray mass spectrometry, of 60,800 and 61,615 Da, respectively, an increase for the recombinant enzyme equivalent to the mass of the His(6)-tag . However, rCMO expressed in Saccharomyces cerevisiae consistently exhibited a mass some 50 Da larger than rCMO expressed in bacteria . Edman degradation confirmed that rCMO purified from the E . coli system and nCMO shared the same N-terminal sequence, whereas no sequence information could be obtained for rCMO expressed in yeast . Therefore, the yeast-expressed enzyme possesses an additional posttranslational modification(s), possibly acylation, at the N-terminus . Expression in E . coli is the preferred system for future site-directed mutagenesis studies and crystallization efforts .

Microbiology, 2001 Jan, 147(Pt 1), 121 - 33
The chlorobenzoate dioxygenase genes of Burkholderia sp . strain NK8 involved in the catabolism of chlorobenzoates; Francisco P Jr et al.; Burkholderia sp . NK8 grows abundantly on 3-chlorobenzoate (3CB),4-chlorobenzoate (4CB) and benzoate . The genes encoding the oxidation of (chloro)benzoates (cbeABCD) and catechol (catA, catBC), the LysR-type regulatory gene cbeR and the gene cbeE with unknown function, all of which form a single cluster in NK8, were cloned and analysed . The protein sequence of chlorobenzoate 1,2-dioxygenase (CbeABC) is 50-65% identical to the benzoate dioxygenase (BenABC) of Acinetobacter sp . ADP1, toluate dioxygenase (XylXYZ) of the TOL plasmid pWW0 and 2-halobenzoate dioxygenase (CbdABC) of Burkholderia cepacia 2CBS . Disruption of the cbeA gene resulted in the simultaneous loss of the ability to grow on benzoate and monochlorobenzoates, indicating the involvement of the cbeABCD genes in the degradation of these aromatics . The cbeABCD genes are preceded by catA, the gene for catechol dioxygenase . lacZ transcriptional fusion studies in Pseudomonas putida showed that catA and cbeA are co-expressed under the positive control of cbeR, a LysR-type transcriptional regulatory gene . The cbeA::lacZ transcriptional fusion studies showed that the inducers of the genes are 3CB, 4CB, benzoate and probably cis,cis-muconate . On the other hand, 2-chlorobenzoate (2CB) did not activate the expression of the genes . The chlorobenzoate dioxygenase was able to transform 2CB, 3CB, 4CB and benzoate at considerable rates . 2CB yielded both catechol and 3-chlorocatechol (3CC), and 3CB gave rise to 4-chlorocatechol and 3CC as the major and minor intermediate products, respectively, indicating that the NK8 dioxygenase lacks absolute regiospecificity . The absence of growth of NK8 on 2CB, despite its considerable degradation activity against 2CB, is apparently due to the inability of CbeR to recognize 2CB as an inducer of the expression of the cbe genes.

J Bacteriol, 2001 Mar, 183(5), 1819 - 23
Gene structures and regulation of the alkane hydroxylase complex in Acinetobacter sp . strain M-1; Tani A et al.; In the long-chain n-alkane degrader Acinetobacter sp . strain M-1, two alkane hydroxylase complexes are switched by controlling the expression of two n-alkane hydroxylase-encoding genes in response to the chain length of n-alkanes, while rubredoxin and rubredoxin ruductase are encoded by a single gene and expressed constitutively.

Arch Dis Child, 2001 Feb, 84(2), 156 - 9
Significance of fever in Jamaican patients with homozygous sickle cell disease; Wierenga KJ et al.; OBJECTIVE: To investigate the cause and outcome of high fever in Jamaican children with homozygous sickle cell disease . DESIGN: Retrospective review of febrile episodes in a three year period (1 September 1993 to 31 August 1996) . SETTING: Sickle cell clinic, an outpatient clinic in Kingston run by the Medical Research Council Laboratories (Jamaica) . PATIENTS: Patients with homozygous sickle cell disease under 17 years of age presenting with an axillary temperature >/= 39.0 degrees C (102.4 degrees F) . MAIN OUTCOME MEASURES: Diagnosis, death . RESULTS: There were 165 events in 144 patients (66 (45.8%) boys) with a median age of 6.1 years . Bacteraemia was found in 10 (6.1%) events (three Streptococcus pneumoniae, two Haemophilus influenzae type b, two Salmonella sp, one Escherichia coli, one Enterobacter sp, and one Acinetobacter sp), and urinary tract infections in four (2.4%) . All cultures of cerebrospinal fluid were sterile . Acute chest syndrome occurred in 36 (21.8%) events . A painful crisis was associated with 45 (27.3%) events and was the only pathology identified in 20 events (12.1%) . Hospital admission was necessary in 66 cases including all those with bacteraemia and 31 with acute chest syndrome . There were two deaths: a 5 year old boy with septic shock associated with H influenzae septicaemia, and a 3 year old boy with the acute chest syndrome . CONCLUSIONS: Painful crisis and acute chest syndrome were the most common complications associated with high fever, but other important associated features included bacteraemia and urinary tract infection . Enteric Gram negative organisms accounted for 50% of positive blood cultures.

Antimicrob Agents Chemother, 2001 Feb, 45(2), 583 - 8
Characterization of OXA-25, OXA-26, and OXA-27, molecular class D beta-lactamases associated with carbapenem resistance in clinical isolates of Acinetobacter baumannii; Afzal-Shah M et al.; Carbapenem resistance in Acinetobacter spp . is increasingly being associated with OXA-type beta-lactamases with weak hydrolytic activity against imipenem and meropenem . Such enzymes were characterized from Acinetobacter isolates collected in Belgium, Kuwait, Singapore, and Spain . The isolates from Spain and Belgium had novel class D beta-lactamases that were active against carbapenems . These were designated OXA-25 and OXA-26, respectively, and had >98% amino acid homology with each other and with the OXA-24 enzyme recently described by others from an Acinetobacter isolate collected elsewhere in Spain . The isolate from Singapore had OXA-27 beta-lactamase, another novel class D type with only 60% homology to OXA-24, -25, and -26, but with 99% homology to OXA-23 (ARI-1), described previously from an Acinetobacter baumannii isolate collected in Scotland . Sequence data were not obtained for the carbapenem-hydrolyzing OXA enzyme from the isolate from Kuwait; nevertheless, the enzyme was phenotypically similar to OXA-25 and -26 . The enzymes OXA-23, -24, -25, -26, and -27 retained the STFK and SXV motifs typical of class D beta-lactamases, but the YGN motif was altered to FGN . The KTG motif was retained by OXA-27 and -23 but was replaced by KSG in OXA-24, -25, and -26 . OXA-25 and -26 enzymes were strongly active against oxacillin, but unusually for an OXA-type beta-lactamase, OXA-27 had apparently weak activity, although measurement was complicated by biphasic kinetics . None of the new enzymes was transmissible to Escherichia coli recipients . Many Acinetobacter isolates are multiresistant to other antibiotics, and the emergence of class D enzymes with carbapenem-hydrolyzing activity is a disturbing development for antimicrobial chemotherapy.

Rev Med Chil, 1999 Aug, 127(8), 926 - 34
{Antimicrobial resistance of different Acinetobacter baumannii biotypes isolated in the northern region of Chile}; Silva J et al.; BACKGROUND: Acinetobacter baumannii nosocomial outbreaks are common and the microorganism is frequently resistant to multiple antimicrobials . There is little information about Acinetobacter baumannii antimicrobial susceptibility in the northern region of Chile . AIM: To identify different Acinetobacter baumannii biotypes isolated from clinical samples and to determine their antimicrobial susceptibility . MATERIAL AND METHODS: One hundred twenty three Acinetobacter baumannii isolates were studied . The identification and typing of Acinetobacter baumannii was based on phenotypic characteristics . Antimicrobial susceptibility was investigated using agar dilution techniques . RESULTS: Most Acinetobacter baumannii strains were isolated from wounds, urinary and respiratory infections . Seven biotypes were isolated, being biotype 9 the most frequent . Imipenem was the antimicrobial with the higher activity against the microorganism . Amikacin, cefoperazonesulbactam, ampicillinsulbactam and ceftazidime had a moderate activity . There were high resistance levels to ampicillin and older cephalosporins . CONCLUSIONS: Acinetobacter baumannii is emerging as a significant nosocomial pathogen in Chile and shows high resistance rates to multiple antibiotics.

Med Clin North Am, 2000 Nov, 84(6), 1391 - 406
Antibiotic synergy and antagonism; Acar JF; The field of synergistic combinations of antibiotics is extremely broad and mostly has been explored in vitro . Some fixed combinations were successfully developed commercially . A few combinations were tested in animal models, and a smaller number was studied in human patients . Any practitioner in infectious diseases has some individual cases, published or unpublished, which add some evidence to the role of synergistic combinations in difficult therapy problems--either on the side of the patient when immunosuppressed or on the side of the bacterial strain, when multiply resistant . MRSA, VISA, E . faecium resistant to penicillin G and highly resistant to aminoglysocides and to vancomycin, P . aeruginosa resistant to ceftazidime and imipenem, and Acinetobacter baumani resistant to imipenem are some of the bacterial strains dangerous for the patient and the hospital, which trigger the imagination of the microbiologist and physician to find a satisfactory treatment . On the side of the drug industry, the increasing knowledge of resistance mechanisms and of synergistic mechanisms may open some new approach, such as efflux inhibitors, a membrane-active compound that can be combined with a partner antibiotic . Antagonism between antibiotics would be worthwhile to study because it likely contributes to the disadvantages of the inappropriate use of antimicrobial combinations.

FEMS Microbiol Lett, 2001 Jan 1, 194(1), 53 - 7
Occurrence of a new metallo-beta-lactamase IMP-4 carried on a conjugative plasmid in Citrobacter youngae from the People's Republic of China; Hawkey PM et al.; During the course of an antimicrobial resistance surveillance programme in Guangzhou, the People's Republic of China, single strains of Citrobacter youngae and Pseudomonas aeruginosa were identified which were resistant to imipenem and found to carry the carbapenemase gene bla(IMP) . PCR screening of the citrobacter strain with specific primers for the bla(IMP) type genes gave a 587-bp product which when sequenced gave 100% homology with the bla(IMP-4) sequence reported recently from Acinetobacter spp . The determinant in the C . youngae strain was found to be located on a 156-kb plasmid capable of transfer to Escherichia coli UB1637 by conjugation . Sequencing of the bla(IMP-4) open reading frame in the C . youngae strain and adjacent sequences not only confirmed the presence of bla(IMP-4) but also identified that a conserved core site found within the 59-bp element of integrons was present and the same as the one described in the only other occurrence of bla(IMP-4) in Acinetobacter spp . isolated from an intensive care unit in Hong Kong . This is the second report of transferable carbapenemase genes in Enterobacteriaciae outside of Japan and the first in the People's Republic of China . Under the selective pressure of carbapenems and extended spectrum cephalosporins use we might expect this gene to spread and widespread surveillance should be instituted.

Am Surg, 2000 Dec, 66(12), 1110 - 4; discussion 1114-5
Effects of empiric antibiotic administration for suspected pneumonia on subsequent opportunistic pulmonary infections; Koontz CS et al.; Optimal guidelines for empiric antibiotic (EAB) therapy in cases of suspected post-traumatic ventilator-associated pneumonia (VAP) are not well defined . EAB administration is thought to increase the incidence of opportunistic organisms; however, culture-directed (as opposed to empiric) treatment may delay antibiotic administration with possible adverse consequences . Our goal was to examine the impact of EAB administration on the incidence of subsequent VAP and opportunistic organisms in a series of critically injured patients with sepsis syndrome . This is a retrospective review of all patients admitted to a Level I trauma center who underwent multiple fiberoptic bronchoscopies (FOBs) for diagnosis of suspected VAP as the cause of postinjury sepsis syndrome . The relationships between EAB administration, positive cultures (>10(5) colony-forming units) at repeat FOB, and prevalence of opportunistic organisms (methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas species, Acinetobacter species, and/or yeast) were evaluated . Over a 13-month period ending on January 1, 1999, 36 intubated trauma patients underwent more than one FOB during their intensive care unit stay . Twenty-nine patients received EAB immediately after the initial FOB . There was no difference in the rate of EAB administration in patients who developed subsequent VAP after initial FOB (19 of 24, 79%) versus those who did not develop VAP (10 of 12, 83%; P = 0.65) . There were 30 VAPs diagnosed in 58 subsequent FOBs (i.e., after the initial FOB) of which 23 were due to an opportunistic organism compared with two VAPs due to an opportunistic organism diagnosed at initial FOB (P < 0.001) . Twenty-one of the 23 opportunistic VAPs at subsequent FOBs had received EAB before the first FOB compared with four of seven nonopportunistic organisms (P = 0.06) . Administration of EAB does not impact the incidence of subsequent VAP . However, EAB may be related to the development of subsequent opportunistic pulmonary infections.

Med Dosw Mikrobiol, 2000, 52(3), 267 - 73
{Comparative evaluation of bacteria identification from the Acinetobacter genus using a commercially available API 20NE system, PCR and RFLP techniques}; Wydmuch Z et al.; A study was carried out for identification of 50 Acinetobacter strains isolated from various clinical materials . Using classic methods the following species were identifies: Acinetobacter sp . (68%), Acinetobacter baumanii (24%) and Acinetobacter lwofii (8%) . In all strains the recA gene was found of 435-500 pz size which confirms their belonging to that genus . Amplification products were digested with restriction enzymes Mbol and HinfI (RFLP) and their detection was carried out on agarose gel by electrophoresis methods, owing to that the arrangement of gene fragment characteristic of each strain was obtained . After careful analysis restriction patterns were obtained corresponding to the following genome species: Acinetobacter baumanii (60%), Acinetobacter sp . 3 (28%) and Acinetobacter lwoffii (12%) . The methods of molecular biology made possible a more precise classification of the studied strains according to species . Certain strains determined as Acinetobacter sp . by the API 20NE system were found to be Acinetobacter baumanii, Acinetobacter sp . 3 or Acinetobacter lwofii when determined by the PCR/RFLP method.

Arch Pediatr, 2000 Dec, 7(12), 1268 - 73
{Nosocomial infections in neonatal and pediatric intensive care . The appeal of ciprofloxacin}; Nejjari N et al.; Nosocomial infections, caused by multiresistant bacteria, are very common in neonatal intensive care units (NIU) and they engage the vital prognosis . MATERIAL AND METHODS: From January 1994 to December 1995, 29 children suffered from nosocomial infections due to multiresistant bacteria . RESULTS: Bacteria were isolated in blood cultures and/or in cerebrospinal fluid and included Klebsiella (14 cases), Enterobacter (eight cases), Pseudomonas (three cases), Acinetobacter (one case), Stenotrophomonas maltophilia (one case) and Flavobacterium odorantum (one case) . After preliminary antibiotic therapy, ciprofloxacin was introduced and associated with another antibiotic for 10 days . Outcome was favorable in 25 cases with sterilization of blood culture . Four deaths were due to acute respiratory failure . One case of skin rash and five cases of transient thrombocytopenia were observed during the six days of ciprofloxacin therapy . No articular complication and no dental abnormalities were observed during the 14-38-month follow-up . Ciprofloxacin appears to be a good therapeutic choice for the treatment of severe nosocomial infections in NICU . Side effects are rare, mild, and transient . However, the prevention of nosocomial infection remains essential.

Infection, 2000 Nov-Dec, 28(6), 395 - 7
Community-acquired Acinetobacter meningitis in adults; Chang WN et al.; Community-acquired Acinetobacter meningitis in adults is an extremely rare infection of the central nervous system (CNS) . Here we report one adult case of this rare CNS infection and review the clinical data of another seven cases reported in the English language literature . In total, eight patients (six men and two women) aged between 19 and 63 years were studied.The causative pathogen in our patient was Acinetobacter baumannii; in the other reported cases they were most likely Acinetobacter Iwoffii, Acinetobacter johnsonii, Acinetobacter junii, a genomic species 3 or 6 . No underlying disease was found in seven of the eight cases and six of the eight patients acquired the infections before the age of 30 years . Fever and consciousness disturbance were the most common clinical manifestations . Waterhouse-Friderichsen syndrome (WFS) was found in two cases . Unlike the Acinetobacter strains found in nosocomial infections, the strain of Acinetobacter meningitis in the community-acquired case did not show multiple antibiotic resistance . Most adult patients with community-acquired Acinetobacter meningitis can be saved by timely therapy with appropriate antibiotics before deterioration of the systemic condition and impairment of consciousness.

Int J Antimicrob Agents, 2001 Jan, 17(1), 45 - 50
Ceftibuten stability to active-site serine and metallo-beta-lactamases; Perilli M et al.; Ceftibuten is an oral third-generation cephalosporin active against a wide range of bacteria and shows an improved stability to hydrolysis by several beta-lactamases because of the carboxyethilidine moiety at position 7 of the ss-acyl side chain . The kinetic interactions between ceftibuten and active-site serine and metallo-ss-lactamases were investigated . The activity of several TEM-derived extended spectrum beta-lactamases (ESbetaLs) against ceftibuten, cefotaxime and ceftazidime was compared using K(m), K(cat) and K(cat)/K(m) . Ceftibuten behaved as a poor substrate for class A and B beta-lactamases compared with cefotaxime . The chromosomal class C beta-lactamase from Enterobacter cloacae 908R gave a high K(cat) value (21 s(-1)), whereas there was poor activity with enzymes from Acinetobacter baumannii and Morganella morganii and ceftibuten . Ceftibuten resists hydrolysis in the presence of typical respiratory or urogenital-tract pathogens producing beta-lactamases.

J Clin Microbiol, 2001 Jan, 39(1), 389 - 91
Acinetobacter baumannii at a tertiary-care teaching hospital in Jerusalem, Israel; Simhon A et al.; In a retrospective 10-year analysis of 3,536 patient-unique isolates, Acinetobacter baumannii imipenem susceptibility declined from 98.1 (1990) to 64.1% (2000), and ciprofloxacin susceptibility decreased from 50.5 to 13.1% . Imipenem median zone diameters decreased from 27 . 7 (1997) to 18.8 mm (2000) . No outbreaks were detected . Two clusters were identified for 41 strains genotyped by pulsed-field gel electrophoresis, but imipenem resistance was not clonal.

J Clin Microbiol, 2001 Jan, 39(1), 228 - 34
Epidemiology and infection control implications of Acinetobacter spp . in Hong Kong; Houang ET et al.; In a previous study, we showed that Acinetobacter genomic DNA group 3 was the most common species among blood culture isolates and was commonly found on superficial carriage sites of the healthy and the sick, which are different findings from those reported in Europe and North America . We used amplified ribosomal DNA restriction analysis and pulsed-field gel electrophoresis to study further the molecular epidemiology of acinetobacters in our region . Over a study period of 6 weeks with 136 consecutive routine clinical isolates (1.33% of all specimens), genomic DNA groups 2 (Acinetobacter baumannii), 3, and 13TU were obtained from 59 of 69 positive patients . There is a significant difference in the specimen sources of the three genomic DNA groups, with group 13TU being significantly associated with the respiratory tract (chi-square exact test, P = 0.0064) . Settle plates showed a significantly heavier environmental load from the intensive care unit (ICU) than from the four surgical wards examined (22 of 70 versus 76 of 120 plates with <5 colonies; chi-square test, P < 0 . 0001) . Genomic group 3 accounted for 6 of 12 clusters of possibly related strains among patients, between patients and the ICU environment, and in the ICU environment . Genomic groups 2 and 3 accounted for 21% of the 132 genomically identified isolates recovered from 21 of 41 local vegetables, 53 of 74 fish and meat samples, and 22 of 60 soil samples . Group 13TU was present only in patients' immediate surroundings . The role played by the environment and by human carriage should be evaluated in order to devise a cost-effective infection control program pertinent to our situation of acinetobacter endemicity.

J Clin Microbiol, 2001 Jan, 39(1), 183 - 90
Contemporary assessment of antimicrobial susceptibility testing methods for polymyxin B and colistin: review of available interpretative criteria and quality control guidelines; Gales AC et al.; The emergence of infections caused by multidrug-resistant Pseudomonas aeruginosa and Acinetobacter spp . has necessitated the search for alternative parenteral agents such as the polymyxins . The National Committee for Clinical Laboratory Standards (NCCLS) documents do not currently provide interpretative criteria for the testing of the polymyxins, colistin and polymyxin B . Therefore, an evaluation of the antimicrobial activity of colistin and polymyxin B was initiated using 200 bloodstream infection pathogens collected through the SENTRY Antimicrobial Surveillance Program . All susceptibility tests were performed according to the NCCLS recommendations . Polymyxin B and colistin displayed a nearly identical spectrum of activity, exhibiting excellent potency against P . aeruginosa (MIC(90), 2 microg/ml) and Acinetobacter sp . (MIC(90), 2 microg/ml) . In contrast, they showed limited activity against some other nonfermentative bacilli such as Burkholderia cepacia (MIC(90), >/=128 microg/ml) . Excellent correlation was achieved between broth microdilution and agar dilution tests (r = 0.96 to 0.98); 94.3% of the results were +/-1 log(2) dilution between the methods used for both compounds . At a resistance breakpoint of >/=4 microg/ml for both agents, unacceptable false-susceptible or very major errors were noted for colistin (5%) and polymyxin B (6%) . Modified zone criteria for colistin (</=11 and >/=14 mm) and polymyxin B (</=10 and >/=14 mm) were suggested, but some degree of error persisted (>/=3.5%) . It is recommended that all susceptible disk diffusion results be confirmed by MIC tests using the preferred reference NCCLS method . The quality control (QC) ranges listed in the product package insert require an adjusted range by approximately 3 mm for both NCCLS gram-negative quality control strains . This evaluation of in vitro susceptibility test methods for the polymyxin class drugs confirmed continued serious testing error with the disk diffusion method, the possible need for breakpoint adjustments, and the recalculation of disk diffusion QC ranges . Clinical laboratories should exclusively use MIC methods to assist the therapeutic application of colistin or polymyxin B until disk diffusion test modifications are sanctioned and published by the NCCLS.

J Clin Microbiol, 2001 Jan, 39(1), 8 - 13
Identification of epidemic strains of Acinetobacter baumannii by integrase gene PCR; Koeleman JG et al.; Forty-eight clinical Acinetobacter isolates with different epidemic behavior were investigated for the presence of integrons and plasmids and for antibiotic susceptibility . Integrons were demonstrated in 50% of the strains by an integrase gene PCR . Epidemic strains of Acinetobacter baumannii were found to contain significantly more integrons than nonepidemic strains . Also, the presence of integrons was significantly correlated with simultaneous resistance to several antibiotics . Plasmids were detected in 42% of the strains . However, there was no significant correlation between the numbers of plasmids and integrons in Acinetobacter species strains, no significant difference in the number of plasmids between epidemic and nonepidemic A . baumannii strains, and no significant correlation between the presence of plasmids and antibiotic resistance . Hence, it is likely that integrons play an important role in antibiotic resistance and thereby in the epidemic behavior of A . baumannii . Because the integrase gene PCR identified almost three-quarters of the epidemic A . baumannii isolates (17 of 23), this seems to be a rapid and simple technique for the routine screening and identification of clinical A . baumannii isolates with epidemic potential.

Chirality, 2001 Jan, 13(1), 40 - 2
Enantioselective synthesis of tert-butyl tert-butanethiosulfinate catalyzed by cyclohexanone monooxygenase; Colonna S et al.; Cyclohexanone monooxygenase from Acinetobacter calcoaceticus catalyzes the asymmetric oxidation of tert-butyl disulfide to enantiomerically pure (R)-tert-butyl tert-butanethiosulfinate . Lower enantioselectivities and conversions were observed in the oxidation of i-propyl, n-butyl, p-tolyl tert-butyl disulfides and alkylthiophosphonates .

Appl Environ Microbiol, 2001 Jan, 67(1), 293 - 9
Evaluation of biological and physical protection against nuclease degradation of clay-bound plasmid DNA; Demaneche S et al.; In order to determine the mechanisms involved in the persistence of extracellular DNA in soils and to monitor whether bacterial transformation could occur in such an environment, we developed artificial models composed of plasmid DNA adsorbed on clay particles . We determined that clay-bound DNA submitted to an increasing range of nuclease concentrations was physically protected . The protection mechanism was mainly related to the adsorption of the nuclease on the clay mineral . The biological potential of the resulting DNA was monitored by transforming the naturally competent proteobacterium Acinetobacter sp . strain BD413, allowing us to demonstrate that adsorbed DNA was only partially available for transformation . This part of the clay-bound DNA which was available for bacteria, was also accessible to nucleases, while the remaining fraction escaped both transformation and degradation . Finally, transformation efficiency was related to the perpetuation mechanism, with homologous recombination being less sensitive to nucleases than autonomous replication, which requires intact molecules.

Rev Med Chil, 2000 Aug, 128(8), 863 - 7
{Presence of integrons and their relationships with the resistance to third generation cephalosporins among nosocomial isolates of Acinetobacter baumannii}; Ramirez C et al.; BACKGROUND: Acinetobacter baumannii is an important etiological agent causing nosocomial infections . High level of resistance for different kind of antimicrobials has been observed, including beta-lactam antibiotics . This feature, chromosomal or plasmid encoded, has been associated to integrons harbouring antibiotic resistance gene cassettes . AIMS: To investigate the presence of integrons among clinical isolates resistant to third generation cephalosporins (3GC) . MATERIAL AND METHODS: One hundred A . baumannii strains isolated from several Chilean hospitals were included in this study . Minimal inhibitory concentrations (MIC) of 3GC by an agar dilution method were carried out . Integrons class 1, 2 and 3 were investigated by colony blot hybridisation and confirmed by PCR . RESULTS: High level of resistance to all assayed 3GC was observed . On the other hand, integron class 2 was the most prevalent (77% of isolates) followed by integron class 1 (52%) . Forty six percent of isolates hybridised with probes for both of them . However, no positive hybridisation was detected for integron class 3 . CONCLUSIONS: Nevertheless, most isolates harboured one or both class of integron; there was no direct relationship between the presence of these genetic structures and the resistance to this kind of beta-lactam antibiotics.

Carbohydr Res, 2000 Nov 17, 329(3), 549 - 60
Synthesis of neoglycoproteins containing D-glycero-D-talo-oct-2-ulopyranosylonic acid (Ko) ligands corresponding to core units from Burkholderia and Acinetobacter lipopolysaccharide; Wimmer N et al.; Glycal esters of Kdo derivatives were converted into 2,3-anhydro intermediates, which were transformed into D-glycero-D-talo-oct-2-ulopyranosylonic acid (Ko), as well as 3-O- and 4-O-p-nitrobenzoyl-Ko derivatives . The exo-allyl orthoester derivative, methyl {5,7,8-tri-O-acetyl-4-O-(4-nitrobenzoyl)-2,3-O-{(1-exo-allyloxy)-ethylidene}-D-glycero-beta-D-talo-oct-2-ulopyranos}onate, prepared from the 4-O-pNBz-protected Ko derivative, was elaborated into the alpha-Ko allyl ketoside, the reducing disaccharide alpha-Kdop-(2-->4)-Ko and the disaccharide alpha-Kdop-(2-->4)-Kop-(2-->OAll) . Conversely, methyl{4,5,7,8-tetra-O-acetyl-3-O-(4-nitrobenzoyl)-alpha-D-glycero-D-talo-2-octulopyranosyl bromide}onate {Carbohydr . Res., 244 (1993) 69-84}, was coupled with a Kdo acceptor to give the disaccharide alpha-Kop-(2-->4)-Kdop-(2-->OAll) after orthoester rearrangement and deprotection . The allyl glycosides were treated with cysteamine and converted into neoglycoproteins . The ligands correspond to inner core units from Acinetobacter haemolyticus and Burkholderia cepacia lipopolysaccharides.

Chemotherapy, 2001 Jan-Feb, 47(1), 19 - 28
Acinetobacter infections in patients with human immunodeficiency virus infection: microbiological and clinical epidemiology; Manfredi R et al.; BACKGROUND: We evaluated the role of complications caused by Acinetobacter spp . in the setting of HIV infection . METHODS: Clinical records of 1,923 consecutive HIV-infected patients hospitalized in a 9-year period were retrospectively reviewed, in order to identify all cases of Acinetobacter spp . complications, and to assess their occurrence and outcome according to several epidemiological, clinical and laboratory parameters . RESULTS: Ten patients out of 1,923 (0.52%) developed Acinetobacter spp . infections: sepsis in four cases, urinary tract infection in three, pneumonia in two and septicaemic pneumonia in the remaining patient . All patients were severely immunocompromised, as shown by a mean CD4+ lymphocyte count of 122 cells/microl and a frequent prior diagnosis of AIDS . As opposed to other infections, septicaemia was associated with a significantly lower CD4+ cell count and a more frequent occurrence of neutropenia . Hospital-acquired Acinetobacter spp . infections were significantly more frequent than community-acquired ones, and prevailingly involved patients with AIDS and leucopenia, being responsible for frequent blood dissemination . Antimicrobial, corticosteroid and cotrimoxazole treatment were frequently carried out during the month preceding disease onset . Antibiotic susceptibility studies proved the complete resistance of microbial isolates to ampicillin and cephalothin and poor sensitivity to second-generation cephalosporins and gentamicin, while greater susceptibility was shown to ceftazidime, netilmicin and amikacin, followed by piperacillin, cotrimoxazole and quinolones . Appropriate antimicrobial treatment led to clinical and microbiological cure in all cases, with no related mortality or relapses . CONCLUSIONS: Since only 23 episodes of HIV-associated Acinetobacter spp . infections have been described to date in 11 different reports (nine cases of bacteraemia, eight of pneumonia, two of urinary tract involvement, one of intravenous access device infection, one of meningitis and two with unspecified localization), our series represents the largest one dealing with HIV-associated Acinetobacter spp . infections . According to our experience, Acinetobacter spp . may be responsible for appreciable morbidity among patients with HIV infection, above all when a low CD4+ cell count, neutropenia and hospitalization are present . Clinicians and microbiologists who work in the field of HIV infection should consider the potential pathogenic role of Acinetobacter spp . organisms even in the absence of some presumed risk factors, because of the relationship between these infections and immunodeficiency, hospitalization, other infectious complications, prior antibiotic and steroid treatment and extended antimicrobial resistance patterns .

Antimicrob Agents Chemother, 2001 Jan, 45(1), 267 - 74
Evaluation of current activities of fluoroquinolones against gram-negative bacilli using centralized in vitro testing and electronic surveillance; Sahm DF et al.; Given the propensity for Enterobacteriaceae and clinically significant nonfermentative gram-negative bacilli to acquire antimicrobial resistance, consistent surveillance of the activities of agents commonly prescribed to treat infections arising from these organisms is imperative . This study determined the activities of two fluoroquinolones, levofloxacin and ciprofloxacin, and seven comparative agents against recent clinical isolates of Enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia using two surveillance strategies: 1) centralized in vitro susceptibility testing of isolates collected from 27 hospital laboratories across the United States and 2) analysis of data from The Surveillance Network Database-USA, an electronic surveillance network comprising more than 200 laboratories nationwide . Regardless of the surveillance method, Enterobacteriaceae, P . aeruginosa, and A . baumannii demonstrated similar rates of susceptibility to levofloxacin and ciprofloxacin . Susceptibilities to the fluoroquinolones approached or exceeded 90% for all Enterobacteriaceae except Providencia spp . (</=65%) . Approximately 70% of P . aeruginosa and 50% of A . baumanii isolates were susceptible to both fluoroquinolones . Among S . maltophilia isolates, 50% more isolates were susceptible to levofloxacin than to ciprofloxacin . Overall, the rate of ceftazidime nonsusceptibility among Enterobacteriaceae was 8.7%, with fluoroquinolone resistance rates notably higher among ceftazidime-nonsusceptible isolates than ceftazidime-susceptible ones . Multidrug-resistant isolates were present among all species tested but were most prevalent for Klebsiella pneumoniae and Enterobacter cloacae . No gram-negative isolates resistant only to a fluoroquinolone were encountered, regardless of species . Thus, while levofloxacin and ciprofloxacin have maintained potent activity against Enterobacteriaceae, the potential for fluoroquinolone resistance, the apparent association between fluoroquinolone and cephalosporin resistance, and the presence of multidrug resistance in every species examined emphasize the need to maintain active surveillance of resistance patterns among gram-negative bacilli.

Prikl Biokhim Mikrobiol, 2000 Nov-Dec, 36(6), 656 - 60
{Study of the integral toxicity of aqueous media, polluted by petroleum and petroleum products using bacterial tests}; Fomchenkov VM et al.; A biotest kit was used to assess the integral toxicity level of aquatic medium contamination with petroleum and petroleum-based products . The integral toxicity dynamics was also monitored during biodegradation of petroleum and petroleum-based products by an association of petroleum-degrading strains including Acinetobacter sp., Mycobacterium flavescens, and Rhodococcus sp . The following bacterial tests were used: the bioluminescence (BL) test based on Photobacterium leiognathi; electro-orientation (EO), optoosmotic (OO), and growth test; as well as the reducing activity (RA) test based on the Agrobacterium radiobacter culture . No significant increase in the integral toxicity level of aquatic medium was observed when diesel fuel and kerosene contamination had been subjected to biodegradation . Although express biotests (EO, OO, RA, and BL) detected a pronounced increase in the integral toxicity of aquatic medium, long-term growth biotest revealed no statistically significant increase in the toxicity level.

Prikl Biokhim Mikrobiol, 2000 Nov-Dec, 36(6), 652 - 5
{Plant biotests of soil and water, polluted with petroleum and petroleum products}; Petukhov VN et al.; Reactiona of higher plants (mustard, oat, rye, salad, dill and barley) and microalgae (Euglena gracilis) on the contamination of soil and water with petroleum and oil products was studied . The germination of seeds was analyzed . The length of sprouts, dry biomass and length of plant roots, as well as the optical density of micro-algal broth culture were determined . Negative effects of soil and water contamination with petroleum and oil products on plant and microalgal parameters examined was shown . After biological destruction of contaminants by an association of destructor strains (Acinetobacter sp., Mycobacterium flavescens and Rhodoccocus sp.), the toxicity of contaminated mediums decreased . The data suggest that the integral toxicity of soil and water contaminated with petroleum and oil products and toxicity change during biodestruction of these pollutants can be analyzed by using plant test organisms.

Indian J Ophthalmol, 2000 Jun, 48(2), 129 - 34
Orbital abscess: management and outcome; Suneetha N et al.; PURPOSE: To discuss the diagnosis, management and outcome of various types of orbital abscess . METHODS: The medical records of 13 patients diagnosed and treated for orbital abscess were reviewed . The sources of infection included: paranasal sinusitis (n = 5), odontogenic origin of infection (n = 4), one each, temporal fossa abscess, palatal abscess, furuncle on the nose, and secondary to retrobulbar injection of steroid . Computed tomographic scans revealed the presence of an abscess in all 13 cases . Associated findings on CT scan included: sinus disease (n = 8), cavernous sinus thrombosis (n = 2) and subdural empyema (n = 2) . All patients were treated with intensive, multiple, intravenous antibiotics and early surgical drainage . RESULTS: Purulent material collected surgically from the orbit cultured Staphylococcus aureus (n = 3), two each Pseudomonas aeruginosa, Proteus mirabilis, Acinetobacter species and one each beta-haemolytic Streptococci, Citrobacter frundi and Enterobacter . Final visual acuity was good in 6 patients (6/12-6/6) and no light perception in 6 others . Visual acuity could not be recorded in the infant . The other complications were intracranial abscess (n = 4), cavernous sinus thrombosis (n = 2) and restricted ocular motility (n = 1) . CONCLUSIONS: A high index of suspicion is necessary, along with early institution of appropriate diagnostic imaging, and aggressive medical and surgical treatment for a favourable outcome in cases of orbital abscess.

Chest, 2000 Dec, 118(6), 1739 - 46
Impact of BAL in the management of pneumonia with treatment failure: positivity of BAL culture under antibiotic therapy; Pereira Gomes JC et al.; BACKGROUND: Pneumonia is responsible for 50% of antibiotics prescribed in ICUs . Treatment failure, ie, absence of improvement or clinical deterioration under antibiotic therapy, presents a dilemma to physicians . BAL is an invasive method validated for etiologic diagnosis in pneumonia . Study objective: To evaluate in ICU patients the impact of BAL in the etiologic diagnosis, treatment, and outcome of pneumonia with treatment failure . DESIGN: Prospective clinical study . SETTING: Nonsurgical, medical ICU of a university hospital in Brazil . Patients and participants: Sixty-two episodes of pneumonia treated for at least 72 h without clinical improvement in 53 patients hospitalized for diverse clinical emergencies . Mean duration of hospitalization was 14.2 days . Mean duration of previous antibiotic therapy was 11.4 days . INTERVENTIONS: Bronchoscopy and BAL were performed in each episode . BAL fluid was cultivated for aerobic and anaerobic bacteria; the cutoff considered positive was 10(4) cfu/mL; 10(3) cfu/mL was also analyzed if under treatment . Pneumocystis carinii, fungi, Legionella spp, and Mycobacterium spp were also researched . Measurements and results: Fifty-eight of 62 BAL were performed under antibiotics . The results showed positivity in 45 of 62 (72.6%); 42 of the 45 positive episodes (93.3%) had > 10(4) cfu/mL . The three cases with between 10(3) and 10(4) cfu/mL were considered positive and were treated according to BAL cultures . The main agents were Acinetobacter baumannii (37.1%), Pseudomonas aeruginosa (17.7%), and methicillin-resistant Staphylococcus aureus (MRSA; 16.1%); 46.7% of the episodes (21 of 45) were polymicrobial . BAL results directed a change of therapy in 34 episodes (54.8%) . Overall mortality was 43.5% . There was no difference in mortality among positives, negatives, and patients who changed therapy guided by BAL culture . CONCLUSIONS: (1) BAL fluid examination was positive in 45 of 62 episodes (72.6%), with 58 of 62 BAL performed under antibiotics . This suggests that BAL may be a sensitive diagnostic method for treatment failures of clinically diagnosed pneumonias, even if performed under antibiotics; (2) the main pathogens in our study were A baumannii, P aeruginosa, and MRSA, and approximately 45% of infections were polymicrobial; (3) BAL culture results directed a change of therapy in 75.6% of positive episodes (34 of 45) and in 54.8% of all episodes of treatment failure (34 of 62); and (4) there was no difference in mortality among positives, negatives, and patients who changed therapy guided by BAL culture.

J Bacteriol, 2001 Jan, 183(1), 405 - 9
areCBA is an operon in Acinetobacter sp . strain ADP1 and Is controlled by AreR, a sigma(54)-dependent regulator; Jones RM et al.; The areCBA genes in Acinetobacter sp . strain ADP1, determining growth on benzyl alkanoates, are shown to be transcribed as a single operon and regulated by areR, which encodes a regulatory protein of the NtrC/XylR family . Assays of the Are enzymes and of two insertions of lacZ as a reporter gene have shown that the operon is induced by benzyl acetate, benzyl alcohol, and benzaldehyde, as well as 2- and 4-hydroxybenzyl acetates and benzyl propionate and butyrate . Two adjacent sites of transcriptional initiation were 97 and 96 bp upstream of the start codon for areC, near a sigma(54)-dependent -12, -24 promoter . Inactivation of areR and rpoN (for RNA polymerase sigma(54)) drastically reduced growth rates on the Are substrates and induction of the operon.

J Bacteriol, 2001 Jan, 183(1), 109 - 18
Characterization and evolution of anthranilate 1,2-dioxygenase from Acinetobacter sp . strain ADP1; Eby DM et al.; The two-component anthranilate 1,2-dioxygenase of the bacterium Acinetobacter sp . strain ADP1 was expressed in Escherichia coli and purified to homogeneity . This enzyme converts anthranilate (2-aminobenzoate) to catechol with insertion of both atoms of O(2) and consumption of one NADH . The terminal oxygenase component formed an alpha(3)beta(3) hexamer of 54- and 19-kDa subunits . Biochemical analyses demonstrated one Rieske-type {2Fe-2S} center and one mononuclear nonheme iron center in each large oxygenase subunit . The reductase component, which transfers electrons from NADH to the oxygenase component, was found to contain approximately one flavin adenine dinucleotide and one ferredoxin-type {2Fe-2S} center per 39-kDa monomer . Activities of the combined components were measured as rates and quantities of NADH oxidation, substrate disappearance, product appearance, and O(2) consumption . Anthranilate conversion to catechol was stoichiometrically coupled to NADH oxidation and O(2) consumption . The substrate analog benzoate was converted to a nonaromatic benzoate 1,2-diol with similarly tight coupling . This latter activity is identical to that of the related benzoate 1, 2-dioxygenase . A variant anthranilate 1,2-dioxygenase, previously found to convey temperature sensitivity in vivo because of a methionine-to-lysine change in the large oxygenase subunit, was purified and characterized . The purified M43K variant, however, did not hydroxylate anthranilate or benzoate at either the permissive (23 degrees C) or nonpermissive (39 degrees C) growth temperatures . The wild-type anthranilate 1,2-dioxygenase did not efficiently hydroxylate methylated or halogenated benzoates, despite its sequence similarity to broad-substrate specific dioxygenases that do . Phylogenetic trees of the alpha and beta subunits of these terminal dioxygenases that act on natural and xenobiotic substrates indicated that the subunits of each terminal oxygenase evolved from a common ancestral two-subunit component.

Proc Natl Acad Sci U S A, 2000 Dec 19, 97(26), 14168 - 71
Inorganic polyphosphate kinase and adenylate kinase participate in the polyphosphate:AMP phosphotransferase activity of Escherichia coli; Ishige K et al.; Polyphosphate kinase (PPK), responsible for the processive synthesis of inorganic polyphosphate (polyP) from ATP in Escherichia coli, can transfer in reverse the terminal phosphate residue of polyP to ADP to yield ATP . PolyP also serves as a donor in a polyP:AMP phosphotransferase (PAP) activity observed in extracts of Acinetobacter johnsonii and Myxococcus xanthus . We have found that overexpression of the gene encoding PPK results in a large enhancement of PAP activity in E . coli . The PAP activity requires both PPK and adenylate kinase in equimolar amounts . PPK and adenylate kinase form a complex in the presence of polyphosphate . We discuss a phosphotransfer mechanism that involves both enzymes and enables polyP to be a phospho-donor to AMP.

Appl Environ Microbiol, 2000 Dec, 66(12), 5231 - 5
Thermostable NADP(+)-dependent medium-chain alcohol dehydrogenase from Acinetobacter sp . strain M-1: purification and characterization and gene expression in Escherichia coli; Tani A et al.; NADPH-dependent alkylaldehyde reducing enzyme, which was greatly induced by n-hexadecane, from Acinetobacter sp . strain M-1 was purified and characterized . The purified enzyme had molecular masses of 40 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 160 kDa as determined by gel filtration chromatography . The enzyme, which was shown to be highly thermostable, was most active toward n-heptanal and could use n-alkylaldehydes ranging from C(2) to C(14) and several substituted benzaldehydes, including the industrially important compounds cinnamyl aldehyde and anisaldehyde, as substrates . The alrA gene coding for this enzyme was cloned, and its nucleotide sequence was determined . The deduced amino acid sequence encoded by the alrA gene exhibited homology to the amino acid sequences of zinc-containing alcohol dehydrogenases from various sources . The gene could be highly expressed in Escherichia coli, and the product was purified to homogeneity by simpler procedures from the recombinant than from the original host . Our results show that this enzyme can be used for industrial bioconversion of useful alcohols and aldehydes.

Braz J Infect Dis, 1999 Apr, 3(2), 63 - 79
Results of the 1997 SENTRY Antimicrobial Surveillance Program in Three Brazilian Medical Centers; Sader HS et al.; The SENTRY Antimicrobial Surveillance Program began in January, 1997, and is designed to monitor nosocomial and selected community acquired infections via a worldwide surveillance network of sentinel hospitals distributed equally by geographic location and size . Three sites in Brazil - Rio de Janeiro, Florianopolis, and Sao Paulo - participated in the SENTRY Antimicrobial Surveillance Program stet . Rank order of occurrence and antimicrobial susceptibility of pathogenic species causing bloodstream infections, pneumonia, wound or skin and soft tissue infections, and urinary tract infections (UTI) in hospitalized patients were determined by collecting consecutive isolates over a specified period of time . Antimicrobial susceptibilities of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis obtained from outpatients with respiratory tract infections were also evaluated . The isolates for the evaluated infections were: 1) bloodstream - 20 consecutive isolates in each calendar month during a 12-month period; 2) pneumonia - 100 consecutive isolates over a 6 month period; 3) wound or skin and soft tissue - 50 consecutive isolates over a 3 month period; and 4) UTI - 50 consecutive isolates over a 3 month period . Each hospital also contributed, over a 6 month period, consecutive clinically significant outpatient isolates (one isolate per patient) of S . pneumoniae, H . influenzae, and M . catarrhalis that were considered pathogens in respiratory tract infections . Data collected for each isolate included species identification, antimicrobial susceptibility profile, date of isolation, and specimen type . Molecular studies were performed on selected isolates . A total of 1,241 bacterial strains were obtained; the majority were cultured from hospitalized patients, while 139 were fastidious organisms from community acquired respiratory tract infections . Gram-negative bacilli and S . aureus were the predominant pathogens, and Enterobacter spp . was a significant pathogen . The predominance of P . aeruginosa and Acinetobacter spp . and the significant levels of resistance to most agents are of major concern, as is the epidemic rate of ESBL-producing strains of Klebsiella spp . and E . coli in Brazil, which is much higher than rates seen in other areas of the world . Resistance among P . aeruginosa and the Enterobacteriaceae to fluoroquinolones, oxacillin-resistant S . aureus, and penicillin- and trimethoprim-sulfamethoxazole-resistant pneumococci were other significant resistance issues identified in this surveillance study . Vancomycin resistance among the enterococci, S . aureus, and S . pneumoniae was not identified . This benchmark study will serve as comparison for future surveillance studies, including the ongoing SENTRY program, to monitor emerging resistance trends in Brazil . The high rates of resistance observed in this study underscore the need for global surveillance and local action.

Clin Infect Dis, 2000 Dec, 31(6), 1321 - 30 Epub 2000 Nov 17.
Nonrespiratory Stenotrophomonas maltophilia infection at a children's hospital; Sattler CA et al.; To describe Stenotrophomonas maltophilia infection in children, we reviewed the medical records of patients with isolates from nonrespiratory sites and identified 85 episodes, 51 (60%) of which represented true infection . Forty-two episodes (82.4%) were hospital acquired . Commonly associated with S . maltophilia infection were underlying illness (in 90.2% of cases), previous hospitalizations (in 78.7%), previous antibiotic exposure (in 78.4%), and the presence of a central venous catheter (in 76.5%) . Polymicrobial isolates were obtained in 70.6% of episodes; Pseudomonas aeruginosa and Acinetobacter species were the most common coisolates . Bloodstream infection was the most frequent clinical syndrome (32 {63%} of 51 episodes) . Fever or sepsis occurred in 22 (69%) and shock in 10 (31%) of 32 episodes . Infection at other sites was less severe . The most active antibiotics in vitro were trimethoprim-sulfamethoxazole and ticarcillin-clavulanate . The overall and attributable mortality rates were 12.5% and 6.3%, respectively . S . maltophilia appears to be an important cause of nosocomially acquired bacteremia in children . The significance in children of isolation from other sites is less clear.

J Bacteriol, 2000 Dec, 182(24), 7044 - 52
Mutations in catB, the gene encoding muconate cycloisomerase, activate transcription of the distal ben genes and contribute to a complex regulatory circuit in Acinetobacter sp . strain ADP1; Cosper NJ et al.; Mutants of the bacterium Acinetobacter sp . strain ADP1 were selected to grow on benzoate without the BenM transcriptional activator . In the wild type, BenM responds to benzoate and cis,cis-muconate to activate expression of the benABCDE operon, which is involved in benzoate catabolism . This operon encodes enzymes that convert benzoate to catechol, a compound subsequently degraded by cat gene-encoded enzymes . In this report, four spontaneous mutants were found to carry catB mutations that enabled BenM-independent growth on benzoate . catB encodes muconate cycloisomerase, an enzyme required for benzoate catabolism . Its substrate, cis,cis-muconate, is enzymatically produced from catechol by the catA-encoded catechol 1,2-dioxygenase . Muconate cycloisomerase was purified to homogeneity from the wild type and the catB mutants . Each purified enzyme was active, although there were differences in the catalytic properties of the wild type and variant muconate cycloisomerases . Strains with a chromosomal benA::lacZ transcriptional fusion were constructed and used to investigate how catB mutations affect growth on benzoate . All of the catB mutations increased cis,cis-muconate-activated ben gene expression in strains lacking BenM . A model is presented in which the catB mutations reduce muconate cycloisomerase activity during growth on benzoate, thereby increasing intracellular cis, cis-muconate concentrations . This, in turn, may allow CatM, an activator similar to BenM in sequence and function, to activate ben gene transcription . CatM normally responds to cis,cis-muconate to activate cat gene expression . Consistent with this model, muconate cylcoisomerase specific activities in cell extracts of benzoate-grown catB mutants were low relative to that of the wild type . Moreover, the catechol 1,2-dioxygenase activities of the mutants were elevated, which may result from CatM responding to the altered intracellular levels of cis,cis-muconate and increasing catA expression . Collectively, these results support the important role of metabolite concentrations in controlling benzoate degradation via a complex transcriptional regulatory circuit.

Appl Microbiol Biotechnol, 2000 Oct, 54(4), 451 - 60
Engineering bacterial biopolymers for the biosorption of heavy metals; new products and novel formulations; Gutnick DL et al.; Bioremediation of heavy metal pollution remains a major challenge in environmental biotechnology . One of the approaches considered for application involves biosorption either to biomass or to isolated biopolymers . Many bacterial polysaccharides have been shown to bind heavy metals with varying degrees of specificity and affinity . While various approaches have been adopted to generate polysaccharide variants altered in both structure and activity, metal biosorption has not been examined . Polymer engineering has included structural modification through the introduction of heterologous genes of the biosynthetic pathway into specific mutants, leading either to alterations in polysaccharide backbone or side chains, or to sugar modification . In addition, novel formulations can be designed which enlarge the family of available bacterial biopolymers for metal-binding and subsequent recovery . An example discussed here is the use of amphipathic bioemulsifiers such as emulsan, produced by the oil-degrading Acinetobacter lwoffii RAG-1, that forms stable, concentrated (70%), oil-in-water emulsions (emulsanosols) . In this system metal ions bind primarily at the oil/ water interface, enabling their recovery and concentration from relatively dilute solutions . In addition to the genetic modifications described above, a new approach to the generation of amphipathic bioemulsifying formulations is based on the interaction of native or recombinant esterase and its derivatives with emulsan and other water-soluble biopolymers . Cation-binding emulsions are generated from a variety of hydrophobic substrates . The features of these and other systems will be discussed, together with a brief consideration of possible applications.

Int J Antimicrob Agents, 2000 Nov, 16(3), 309 - 15
Antibiotic usage and resistance - trends in Estonian University Hospitals; Naaber P et al.; The use of antibiotics, type of infections and resistance of prevalent bacteria was surveyed in Tartu University hospitals . The data from two ICUs (1995 and 1998), surgical and internal medicine departments (1998) were compared . Overall antibiotic usage in the ICUs and in the hospital as a whole had increased . There was a significant increase in Gram-positive bacterial infections and a decrease in Gram-negative infections in the ICUs . At the same time, susceptibility to several antibiotics decreased in most of the prevalent Gram-negative aerobes in the ICUs (Acinetobacter spp., Pseudomonas spp., Klebsiella spp.) . Exceptions to this were the greater susceptibility of Pseudomonas spp . to gentamicin and Acinetobacter spp . to imipenem . Some changes in the predominant bacterial populations did not correlate to changes in antibiotic use.

Braz J Infect Dis, 1999 Oct, 3(5), 189 - 196
Evaluation of the in vitro Activity of Two Fourth-Generation Cephalosporins Against Bacterial Samples Isolated From Patients in Several Brazilian Hospitals; Cereda RF et al.; Cefpirome and cefepime are two fourth-generation cephalosporins recently introduced in Brazil . They have a very similar range of in vitro antimicrobial activity, but some differences have been noticed . The goal of this study was to compare the in vitro activity of cefpirome and cefepime against bacterial samples isolated in Brazilian hospitals . We studied 931 samples taken from hospitalized patients between April and June, 1998 . The minimum inhibitory concentration (MIC) was determined by the Etest method . The potency of cefpirome was similar to that of cefepime, except against enterococci and coagulase-negative staphylococci, where cefpirome proved 2-fold more potent . The MIC(90) for cefepime were inferior to cefpirome in response to Klebsiella pneumoniae (MIC(90), 24 and 96microg/mL, respectively), Pseudomonas aeruginosa (MIC(90), 48 and 128microg/mL, respectively), and other Gram-negative organisms (MIC(90), 64 and 256microg/mL, respectively) . Despite the fact that cefpirome presented a slightly broader range of action against Gram-positive bacteria (90% sensitive vs . 78% sensitive to cefepime), and that cefepime presented an equally broad range against Gram-negative bacteria (74% sensitive vs . 65% sensitive to cefpirome), these differences were not considered clinically significant because the sensitivity differed in MIC by less than 2 dilutions . Only 16 (1.7%) of the 931 samples tested showed a significant difference in sensitivity . This study suggests that, except for Acinetobacter sp . and P . aeruginosa, laboratories may routinely test only cefpirome and apply the same category result to cefepime . Since category discrepancies are very rare and cefpirome is slightly less active than cefepime against Enterobacteriaceae, isolates susceptible to cefepime will certanly also be susceptible to cefpirome . To optimize the treatment of severely infected patients, especially where species such as Acinetobacter sp and P . aeruginosa are involved, we recommend that both cephalosporins be tested by using the same susceptibility test method to determine the MIC.

Curr Microbiol, 2000 Dec, 41(6), 379 - 83
Isolation and identification of autochthonous microbiota from a granitic aquifer and its variation after the bottling process; Urmeneta J et al.; The autochthonous microbiota from a granitic aquifer in Spain were studied . Several bacterial strains were isolated and identified . The major components of the microbiota were Pseudomonas-like strains, Flavobacterium, Acinetobacter, and Alcaligenes . The variation in the number of microorganisms after the bottling process was studied . The initial bacterial population increased over the first 5 days after bottling . This increase was higher in samples from polyvinyl chloride bottles . Sonication usually increased the total cell counts . As expected, most of the autochthonous microbiota were not detected in the viable cell counts.

West Indian Med J, 2000 Sep, 49(3), 205 - 9
Prevalence of bacterial pathogens and susceptibility patterns from clinical sources in Trinidad; Orrett FA et al.; During a 12-month period (January-December, 1997), bacterial isolates of specimens from in-patients and out-patients of the Eric Williams Medical Sciences Complex (EWMSC) were reviewed . A total of 3,513 specimens were processed, 43.1% from in-patients and 56.9% from out-patients . Of the 3,513 specimens, 1129 (32.1%) yielded positive cultures . Micro-organisms from wounds, sputum and genital tract accounted for 90.2%, 51.5% and 31.8%, respectively, of all isolates . E coli (17.4%) and Enterococci (12.2%) were the predominant isolates and were also the major pathogens from blood stream infections, 25.8% and 18.2%, respectively, followed by P aeruginosa, 15.2% . High levels of resistance were seen to ampicillin, augmentin (amoxicillin-clavulanic acid) and tetracycline . The most effective antibiotics were ceftazidime (no resistance in E coli Citrobacter spp, non-typhoidal Salmonella and Group B streptococci, 63.2% resistance in Acinetobacter spp, 15.2% in Enterobacter spp, 17.4% in Klebsiella spp.}, gentamicin {no resistance in Enterobacter and Citrobacter spp, and 89.5% in Acinetobacter spp), erythromycin (no resistance in Groups A and B streptococci, 85.1% in S aureus and S pneumoniae) . The spectrum of isolates will provide clinicians with data on which to base their "best guess" aetiologic agent and choice of antibiotics when faced with infectious diseases in areas where laboratory assistance is not readily available.

J Bacteriol, 2000 Dec, 182(23), 6565 - 9
Conversion of 4-hydroxyacetophenone into 4-phenyl acetate by a flavin adenine dinucleotide-containing Baeyer-Villiger-type monooxygenase; Tanner A et al.; An arylketone monooxygenase was purified from Pseudomonas putida JD1 by ion exchange and affinity chromatography . It had the characteristics of a Baeyer-Villiger-type monooxygenase and converted its substrate, 4-hydroxyacetophenone, into 4-hydroxyphenyl acetate with the consumption of one molecule of oxygen and oxidation of one molecule of NADPH per molecule of substrate . The enzyme was a monomer with an M(r) of about 70,000 and contained one molecule of flavin adenine dinucleotide (FAD) . The enzyme was specific for NADPH as the electron donor, and spectral studies showed rapid reduction of the FAD by NADPH but not by NADH . Other arylketones were substrates, including acetophenone and 4-hydroxypropiophenone, which were converted into phenyl acetate and 4-hydroxyphenyl propionate, respectively . The enzyme displayed Michaelis-Menten kinetics with apparent K(m) values of 47 microM for 4-hydroxyacetophenone, 384 microM for acetophenone, and 23 microM for 4-hydroxypropiophenone . The apparent K(m) value for NADPH with 4-hydroxyacetophenone as substrate was 17.5 microM . The N-terminal sequence did not show any similarity to other proteins, but an internal sequence was very similar to part of the proposed NADPH binding site in the Baeyer-Villiger monooxygenase cyclohexanone monooxygenase from an Acinetobacter sp.

J Med Microbiol, 2000 Nov, 49(11), 1047 - 50
Effect of EDTA on the resistance of clinical isolates of Acinetobacter baumannii to the bactericidal activity of normal human serum; Garcia A et al.; Acinetobacter baumannii is an opportunist nosocomial pathogen of world-wide importance and produces severe infections in immunocompromised patients . However, the virulence factors contributing to its pathogenic properties are not well known . The effect of normal human serum against 18 clinical isolates of the most prevalent biotypes of A . baumannii in Chile was investigated . The effect of pre-treatment of the cells with ethylene diamine tetraacetic acid (EDTA) or bismuth subsalicylate (BSS), compounds known to decrease the amount of lipopolysaccharide (LPS) and bacterial capsular polysaccharide (CPS), respectively, in other gram-negative bacteria, was evaluated . Most isolates (16 of 18) showed resistance to normal human serum . Prior treatment with EDTA rendered nine of these isolates susceptible to serum, while seven isolates maintained their resistance . Pre-treatment with BSS did not modify the serum-resistant behaviour of the isolates . The results suggest that LPS might be involved in the resistance of A . baumannii to human serum whereas CPS does not seem to contribute to this property.

Biodegradation, 1999, 10(6), 393 - 8
Purification and properties of pyrophosphatase of Acinetobacter johnsonii 210A and its involvement in the degradation of polyphosphate; Bonting CF et al.; Inorganic pyrophosphatase (E.C . 3.6.1.1) of Acinetobacter johnsonii 210A was purified 200-fold to apparent homogeneity . The enzyme catalyzed the hydrolysis of inorganic pyrophosphate and triphosphate to orthophosphate . No activity was observed with other polyphosphates and a wide variety of organic phosphate esters . The molecular mass of the enzyme was estimated to be 141 kDa by gelfiltration . Sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated a subunit composition of six identical polypeptides with a molecular mass of 23 kDa . The cation Mg2+ was required for activity, the activity with Mn2+, Co2+ and Zn2+ was 48, 48 and 182% of the activity observed with Mg2+, respectively . The enzyme was heat-stable and inhibited by fluoride and iodoacetamide . The analysis of the kinetic properties of the enzyme revealed an apparent Km for pyrophosphate of 0.26 mM . In A . johnsonii 210A, pyrophosphatase may be involved in the degradation of high-molecular polyphosphates under anaerobic conditions: (i) it catalyses the further hydrolysis of pyrophosphate and triphosphate formed from high-molecular weight polyphosphates by the action of exopolyphosphatase, and (ii) it abolishes the inhibition of polyphosphate: AMP phosphotransferase-mediated degradation by pyrophosphate and triphosphate.

Braz J Infect Dis, 2000 Oct, 4(5), 226 - 35
In vitro antimicrobial activity of piperacillin/tazobactam in comparison with other broad-spectrum beta-lactams; Roland RK et al.; Combining tazobactam, a beta-lactamase inhibitor, with the ureidopenicillin, piperacillin, successfully restores the activity of piperacillin against beta-lactamase producing bacteria . Thus, piperacillin/tazobactam is highly active against most clinically important species of Gram-negative and Gram-positive bacteria, including anaerobes . We evaluated the in vitro activity of piperacillin/tazobactam against clinical isolates from a tertiary university hospital located in Sao Paulo, Brazil . Its activity was compared to that of ticarcillin/clavulanic acid, ampicillin/sulbactam, ceftazidime, ceftriaxone, cefotaxime, cefoxitin, aztreonam, and imipenem against 820 isolates (608 Gram-negative and 212 Gram-positive) collected from hospitalized patients in 1999 . The most frequent species tested were Pseudomonas aeruginosa (168/20%), Escherichia coli (139/17%), Acinetobacter spp . (131/16%), and Staphylococcus aureus (76/9%) . Of the isolates studied, 30% were from the bloodstream, 16% from the lower respiratory tract, and 11% from surgical wounds or soft tissue . The isolates were susceptibility tested by the broth microdilution method according to NCCLS procedures . The isolates tested were highly resistant to most antimicrobial agents evaluated . Imipenem resistance was not verified among Enterobacteriaceae, and piperacillin/tazobactam was the second most active beta-lactams against this group of bacteria (80.0% susceptibility) . Extended-spectrum beta-lactamase production was very high among E . coli (approximately 20%) and Klebsiella pneumoniae (approximately 40%) . Imipenem was uniformly active against these species (100% susceptibility) and piperacillin/tazobactam was the second most active compound inhibiting 84.4% of isolates . Pseudomonas aeruginosa was highly resistant to all beta-lactams evaluated and piperacillin/tazobactam was the most active compound against this species . Our results demonstrate an extremely high level of antimicrobial resistance in the hospital evaluated, especially among non-enteric Gram-negative bacilli . Due to this high level of resistance, piperacillin/tazobactam represents an important contribution to the treatment of nosocomial infections.

J Antimicrob Chemother, 2000 Nov, 46(5), 827 - 30
In vivo activity of levofloxacin alone or in combination with imipenem or amikacin in a mouse model of Acinetobacter baumannii pneumonia; Joly-Guillou ML et al.; We evaluated the in vivo activity of levofloxacin alone or in combination with imipenem or amikacin in a mouse model of Acinetobacter baumannii pneumonia using a susceptible strain and one with low-level resistance (MIC/MBC of levofloxacin: 0.06/0.06 and 4/4 mg/L, respectively) . As demonstrated previously with other pathogens, the AUC/MIC ratio predicted the efficacy of fluoroquinolones against A . baumannii . This parameter correlated with bactericidal effect and survival . Combination therapy did not enhance the efficacy of levofloxacin.

J Antimicrob Chemother, 2000 Nov, 46(5), 807 - 10
Comparative activities of polycationic peptides and clinically used antimicrobial agents against multidrug-resistant nosocomial isolates of Acinetobacter baumannii; Giacometti A et al.; The in vitro activity of buforin II, cecropin P1, indolicidin, magainin II and ranalexin, alone and in combination with eight clinically used antimicrobial agents was investigated against 12 multidrug-resistant strains of Acinetobacter baumannii isolated from immunocompromised patients . Antimicrobial activities were measured by MIC, MBC and viable count . The peptides had a varied range of inhibitory values: overall, the organisms were more susceptible to buforin II (MIC range 0.25-16 mg/L), cecropin P1 (0.50-32 mg/L) and magainin II (0.50-16 mg/L) . Synergy occurred when magainin II was combined with beta-lactam antibiotics.

J Clin Microbiol, 2000 Nov, 38(11), 4280 - 1
Acinetobacter baumannii-infected vascular catheters collected from horses in an equine clinic; Vaneechoutte M et al.; Acinetobacter baumannii was isolated from tips clipped from seven intravenous jugular catheters collected from horses in the Ghent University equine clinic . They originated from seven different horses . Three of the seven showed evidence of local infection.

J Clin Microbiol, 2000 Nov, 38(11), 4086 - 95
Emergence and rapid spread of carbapenem resistance during a large and sustained hospital outbreak of multiresistant Acinetobacter baumannii; Corbella X et al.; Beginning in 1992, a sustained outbreak of multiresistant Acinetobacter baumannii infections was noted in our 1,000-bed hospital in Barcelona, Spain, resulting in considerable overuse of imipenem, to which the organisms were uniformly susceptible . In January 1997, carbapenem-resistant (CR) A . baumannii strains emerged and rapidly disseminated in the intensive care units (ICUs), prompting us to conduct a prospective investigation . It was an 18-month longitudinal intervention study aimed at the identification of the clinical and microbiological epidemiology of the outbreak and its response to a multicomponent infection control strategy . From January 1997 to June 1998, clinical samples from 153 (8%) of 1,836 consecutive ICU patients were found to contain CR A . baumannii . Isolates were verified to be A . baumannii by restriction analysis of the 16S-23S ribosomal genes and the intergenic spacer region . Molecular typing by repetitive extragenic palindromic sequence-based PCR and pulsed-field gel electrophoresis showed that the emergence of carbapenem resistance was not by the selection of resistant mutants but was by the introduction of two new epidemic clones that were different from those responsible for the endemic . Multivariate regression analysis selected those patients with previous carriage of CR A . baumannii (relative risk {RR}, 35.3; 95% confidence interval {CI}, 7.2 to 173.1), those patients who had previously received therapy with carbapenems (RR, 4.6; 95% CI, 1.3 to 15.6), or those who were admitted into a ward with a high density of patients infected with CR A . baumannii (RR, 1.7; 95% CI, 1.2 to 2.5) to be at a significantly greater risk for the development of clinical colonization or infection with CR A . baumannii strains . In accordance, a combined infection control strategy was designed and implemented, including the sequential closure of all ICUs for decontamination, strict compliance with cross-transmission prevention protocols, and a program that restricted the use of carbapenem . Subsequently, a sharp reduction in the incidence rates of infection or colonization with A . baumannii, whether resistant or susceptible to carbapenems, was shown, although an alarming dominance of the carbapenem-resistant clones was shown at the end of the study.

J Clin Microbiol, 2000 Nov, 38(11), 3937 - 41
Recognition of two novel phenons of the genus Acinetobacter among non-glucose-acidifying isolates from human specimens; Nemec A et al.; Genomic species diversity among 147 Acinetobacter clinical isolates not belonging to the A . calcoaceticus- A . baumannii (ACB) complex was investigated by phenotypic and genotypic identification methods . The isolates were obtained between 1991 and 1999 from numerous diagnostic laboratories in the Czech Republic and were studied by numerical probabilistic identification using two biochemical frequency matrices and amplified rDNA restriction analysis (ARDRA) . Their final identification was derived from the combined phenotypic and ARDRA results . In total, 102 isolates were unambiguously (n = 89) or presumptively (n = 13) identified as A . lwoffii (n = 63), genomic species 13BJ/14TU (n = 9), A . johnsonii (n = 7), A . haemolyticus (n = 6), A . junii (n = 5), and other genomic species (n < 5 isolates each) . Forty-five isolates could not be identified as belonging to any described species . Among the unidentified isolates two large groups of non-glucose-acidifying, nonhemolytic, and non-gelatinase-producing isolates were distinguished . These groups, designated phenon 1 (n = 17) and phenon 2 (n = 15), had distinctive phenotypic features and novel ARDRA profiles, which suggests that they represent hitherto undescribed Acinetobacter species . Phenon 2 included mainly clinically insignificant isolates from outpatients, while phenon 1 comprised clinically relevant isolates mostly from the blood of hospitalized patients, and its precise taxonomic definition may therefore be of medical importance . Overall, the development of practical methods for identification required for the elucidation of the biological significance of the (genomic) species within the genus Acinetobacter remains a challenging task.

Rev Inst Med Trop Sao Paulo, 2000 Sep-Oct, 42(5), 277 - 82
Biotyping, serotyping and ribotyping as epidemiological tools in the evaluation of Acinetobacter baumannii dissemination in hospital units, Sorocaba, São Paulo, Brazil; Goncalves CR et al.; Dissemination of Acinetobacter baumannii strains in different units of a hospital in Sorocaba, Sao Paulo, Brazil was evaluated over a period of two years . By using biotyping, serotyping and ribotyping, 27 distinct clones were differentiated among 76 strains isolated between 1993-94, from clinical specimens of hospitalized patients . Two clones, 2:O4:A (biotype:serotype:ribotype) and 2:O29:A accounted for the majority of strains widely disseminated in the units during 1993 . The introduction in the hospital setting, of a new clone, 6:O13:B, at the end of 1993 and its predominance through 1994 is discussed . Among 15 strains isolated from neonates, 6 (40%) belonged to the same clone, 2:O4:A . Interestingly, this clone was almost all recovered in neonatal intensive care unit, nursery and in pediatric unit . All strains were susceptible to imipenem and polymyxcin B . Multiresistant strains (up to 12 antimicrobial agents) accounted for 66.7% and 84.8% of the strains isolated in 1993 and in 1994, respectively.

Appl Environ Microbiol, 2000 Nov, 66(11), 4854 - 62
Exogenous isolation of antibiotic resistance plasmids from piggery manure slurries reveals a high prevalence and diversity of IncQ-like plasmids; Smalla K et al.; Antibiotic resistance plasmids were exogenously isolated in biparental matings with piggery manure bacteria as plasmid donors in Escherichia coli CV601 and Pseudomonas putida UWC1 recipients . Surprisingly, IncQ-like plasmids were detected by dot blot hybridization with an IncQ oriV probe in several P . putida UWC1 transconjugants . The capture of IncQ-like plasmids in biparental matings indicates not only their high prevalence in manure slurries but also the presence of efficiently mobilizing plasmids . In order to elucidate unusual hybridization data (weak or no hybridization with IncQ repB or IncQ oriT probes) four IncQ-like plasmids (pIE1107, pIE1115, pIE1120, and pIE1130), each representing a different EcoRV restriction pattern, were selected for a more thorough plasmid characterization after transfer into E . coli K-12 strain DH5alpha by transformation . The characterization of the IncQ-like plasmids revealed an astonishingly high diversity with regard to phenotypic and genotypic properties . Four different multiple antibiotic resistance patterns were found to be conferred by the IncQ-like plasmids . The plasmids could be mobilized by the RP4 derivative pTH10 into Acinetobacter sp., Ralstonia eutropha, Agrobacterium tumefaciens, and P . putida, but they showed diverse patterns of stability under nonselective growth conditions in different host backgrounds . Incompatibility testing and PCR analysis clearly revealed at least two different types of IncQ-like plasmids . PCR amplification of total DNA extracted directly from different manure samples and other environments indicated the prevalence of both types of IncQ plasmids in manure, sewage, and farm soil . These findings suggest that IncQ plasmids play an important role in disseminating antibiotic resistance genes.

J Bacteriol, 2000 Nov, 182(22), 6382 - 90
The malonate decarboxylase operon of Acinetobacter calcoaceticus KCCM 40902 is regulated by malonate and the transcriptional repressor MdcY; Koo JH et al.; A regulatory gene-like open reading frame oriented oppositely to mdcL, coined mdcY, was found upstream from the structural genes of the mdcLMACDEGBH operon in Acinetobacter calcoaceticus KCCM 40902 . To elucidate the function of this gene, mdcY was expressed in Escherichia coli, and the MdcY protein was purified to homogeneity . Its DNA binding activity and binding site were examined by gel retardation and footprinting assays in vitro and by site-directed mutagenesis of the binding sites in vivo . The regulator bound target DNA regardless of the presence of malonate, and the binding site was found centered at -65 relative to the mdcL transcriptional start site and contains a 12-bp palindromic structure (5'-ATTGTA/TACAAT-3') . Using a promoter fusion to the reporter gene luc, we found that the promoter P(mdcY) is negatively regulated by MdcY independent of malonate . However, the promoter P(mdcL) recovered its activity in the presence of malonate . When mdcY was introduced into A . calcoaceticus KCCM 40902 in which the gene is inactivated by an IS3 family element, malonate decarboxylase was significantly repressed in cultures growing in acetate, succinate, or Luria-Bertani medium . However, in cells growing in malonate, malonate decarboxylase was induced, indicating that MdcY is a transcriptional repressor and that malonate or a product resulting from malonate metabolism should be the intracellular inducer of the mdc operon.

Curr Opin Microbiol, 2000 Oct, 3(5), 489 - 95
Carbapenemases: a problem in waiting?
Livermore DM, Woodford N.
Carbapenems are stable to most prevalent beta-lactamases, and chromosomal carbapenemases are restricted to Stenotrophomonas maltophilia, to a few Bacteroides fragilis, and to rare pathogens . Nevertheless, an acquired metallo-beta-lactamase called IMP-1 is beginning to emerge in Pseudomonas aeruginosa and Enterobacteriaceae isolates in Japan, and has also been found in isolates from Singapore . Furthermore, IMP-producing Acinetobacter spp . have been identified in Italy and Hong Kong . Recently a second group of acquired metallo-carbapenemases, the VIM types, has been recorded from P . aeruginosa isolates in five Eurasian countries . Weak carbapenemases belonging to molecular class D are emerging in A . baumannii world-wide, with two sub-groups apparent . A few acquired carbapenemases belonging to molecular class A also have been reported . Finally it has also been shown that enzymes with feeble carbapenemase activity (e.g . AmpC types and some SHV enzymes) may confer resistance in exceptionally impermeable strains; counterwise, even potent carbapenemases, such as IMP-1, may only give a small reduction in susceptibility in Enterobacteriaceae that lack permeability lesions . Is the emergence of carbapenemase a problem waiting to happen?

Prikl Biokhim Mikrobiol, 2000 Sep-Oct, 36(5), 555 - 8
{Respiratory activity of bacteria Acinetobacter calcoaceticus TM-31 during assimilation of alkane hydrocarbons}; Ignatov OV et al.; The respiratory activity of Acinetobacter calcoaceticus TM-31 with resect to alkane hydrocarbons was studied . The dynamics of oxygen consumption by the cells while assimilating n-hexadecane was assayed by a modified technique using an oxygen electrode . The dependence of cell respiratory activity on the amount of n-hexadecane within the concentration range of 0.03-0.66% was determined . It was demonstrated that the cells also displayed respiratory activity towards other medium-chain n-alkanes: hexane, octane, decane, tridecane, and heptadecane . Thus, we demonstrated the possibility of determining alkanes by measuring the respiratory activities of microorganisms.

Cesk Patol, 1999 Jul, 35(3), 106 - 11
{Verification of identification of infectious agents by culture in routine gynecologic cytological screening}; Jurkovic I et al.; The original Bethesda classification system for reporting cervical/vaginal cytologic diagnoses has claimed besides oncologic evaluation also a statement on the presence of infectious agents . Their diagnosis should be followed by appropriate treatment . Based upon the comparison of careful bacterioscopic study in a series of 175 routine cervical smears with the results of microbiological, virological and mycological examinations the following pathogens might be-according to the authors' opinion-diagnosed as highly possible and recommended for laboratory verification: cocci, Gardnerella vaginalis, Klebsiella, Acinetobacter, Morganella Morgani, Candida, Trichomonas vaginalis, Chlamydia trachomatis and human papilloma virus.

J Trauma, 2000 Oct, 49(4), 638 - 45; discussion 645-6
Incidence and susceptibility of pathogenic bacteria vary between intensive care units within a single hospital: implications for empiric antibiotic strategies; Namias N et al.; BACKGROUND: The purpose of this study was to determine whether the incidence of recovery and patterns of antibiotic susceptibility of pathogenic bacteria vary between intensive care units (ICUs) in a single teaching hospital . METHODS: Culture and susceptibility results were collected prospectively for a 3-month period (April through June 1999) in each of the surgical, trauma, and medical ICUs . The number of unique isolates and susceptibility patterns were determined . Susceptibility of isolates among ICUs was compared with chi2 . RESULTS: Statistically significant differences between ICUs in susceptibility to various antibiotics were found for Staphylococcus aureus, Enterococcus sp, Acinetobacter sp, Enterobacter sp, Klebsiella sp, and Pseudomonas sp . Notably, vancomycin-resistant Enterococcus was not seen in the medical ICU, whereas it was seen in both the surgical and trauma ICUs . Klebsiella spp resistant to ceftazidime were seen only in the trauma ICU . The aminoglycosides and quinolones had attenuated activity against Pseudomonas sp in the surgical ICU, whereas they remained highly effective in the trauma ICU . Cefazolin had no activity against the Enterobacter sp in either of the surgical ICUs, but was highly effective in the medical ICU . CONCLUSION: Although the microbiologic results of this study should not be extrapolated to other institutions, the principle is of value . There is variability between ICUs in a single large teaching hospital in susceptibility of bacterial pathogens to various antibiotics . This may have implications in the design of empiric antibiotic strategies and the planning of the hospital formulary . Hospital wide or composite ICU antibiograms are inadequate for planning empiric therapy in the ICU.

Biol Chem, 2000 Aug, 381(8), 755 - 62
Gut bacteria may be involved in interactions between plants, herbivores and their predators: microbial biosynthesis of N-acylglutamine surfactants as elicitors of plant volatiles; Spiteller D et al.; N-Acylamino acids are dominant and widespread constituents of insect oral secretions (regurgitants), serving the insect as biosurfactants in the digestive process . During feeding the conjugates may be introduced into damaged leaves and contribute there to the elicitation of plant defenses such as the induction of volatile biosynthesis . From gut segments of Spodoptera exigua, Mamestra brassicae and Agrotis segetum 23 bacterial strains were isolated, ten of which were able to synthesise typical lepidopteran N-acylamino acids from externally added precursors . Four strains, Providencia rettgeri, Ochrobactrum spec., Myroides odoratus and Acinetobacter sp . genospecies 11 were identified on the basis of their 16 S rDNA . The organisms displayed a very broad substrate tolerance, since fatty acids of different chain length and different degree of saturation were converted into N-acylamino acids . Moreover, most of the proteinogenic amino acids, but not glutamic and aspartic acid, were used as substrates . The dominant occurrence of fatty acids conjugated with glutamine may result from a preferred transport of glutamine from the hemolymph into the gut of the insects . The involvement of bacteria in the biosynthesis of compounds which play a pivotal role in the interaction of plants, herbivores and their predators adds a new trophic level to this complex network of interactions . Due to their short generation cycle and the ease of adaptation endosymbiontic bacteria may have an outstanding importance for the coevolution of plant-insect interactions.

J Bacteriol, 2000 Nov, 182(21), 6145 - 53
Positive selection for mutations affecting bioconversion of aromatic compounds in Agrobacterium tumefaciens: analysis of spontaneous mutations in the protocatechuate 3,4-dioxygenase gene; Parke D; A positive selection method for mutations affecting bioconversion of aromatic compounds was applied to a mutant strain of Agrobacterium tumefaciens A348 . The nucleotide sequence of the A348 pcaHGB genes, which encode protocatechuate 3,4-dioxygenase (PcaHG) and beta-carboxy-cis,cis-muconate cycloisomerase (PcaB) for the first two steps in catabolism of the diphenolic protocatechuate, was determined . An omega element was introduced into the pcaB gene of A348, creating strain ADO2077 . In the presence of phenolic compounds that can serve as carbon sources, growth of ADO2077 is inhibited due to accumulation of the tricarboxylate intermediate . The toxic effect, previously described for Acinetobacter sp., affords a powerful selection for suppressor mutations in genes required for upstream catabolic steps . By monitoring loss of the marker in pcaB, it was possible to determine that the formation of deletions was minimal compared to results obtained with Acinetobacter sp . Thus, the tricarboxylic acid trick in and of itself does not appear to select for large deletion mutations . The power of the selection was demonstrated by targeting the pcaHG genes of A . tumefaciens for spontaneous mutation . Sixteen strains carrying putative second-site mutations in pcaH or -G were subjected to sequence analysis . All single-site events, their mutations revealed no particular bias toward multibase deletions or unusual patterns: five (-1) frameshifts, one (+1) frameshift, one tandem duplication of 88 bp, one deletion of 92 bp, one nonsense mutation, and seven missense mutations . PcaHG is considered to be the prototypical ferric intradiol dioxygenase . The missense mutations served to corroborate the significance of active site amino acid residues deduced from crystal structures of PcaHG from Pseudomonas putida and Acinetobacter sp . as well as of residues in other parts of the enzyme.

Biochem Biophys Res Commun, 2000 Sep 24, 276(2), 797 - 802
Engineering of heterologous cytochrome P450 in Acinetobacter sp.: application for pollutant degradation; Lamb DC et al.; Many organisms do not contain the necessary biochemical armoury to carry out the initial oxidative attack of many pollutant chemicals . In the present study, Acinetobacter sp . strain BD413 has been genetically engineered to express the cytochrome P450 xenobiotic-metabolising enzyme CYP105D1 from Streptomyces griseus that has in its repertoire a diverse array of organic pollutants . Further, it is shown that the transformed Acinetobacter calcoaceticus strain BD413 can grow on pollutants unlike control bacteria not expressing cytochrome P450 and that was reflected in release of radiolabel with growth on radiolabelled chlortoluron . We show that cytochrome P450 can enhance the biodegrading repertoire of A . calcoaceticus and discuss the application of such results to bioremediation strategies .

Diagn Microbiol Infect Dis, 2000 Sep, 38(1), 43 - 50
Evaluation of antibiotic synergy against Acinetobacter baumannii: a comparison with Etest, time-kill, and checkerboard methods; Bonapace CR et al.; Acinetobacter baumannii is becoming increasingly resistant to antibiotics, often requiring combination therapy . Numerous methods exist to detect the presence of in vitro synergy with the time-kill and checkerboard tests being widely used . The Epsilometer test (E test) is a new method that is less labor intensive, but has not been evaluated using a wide range of antimicrobials and organisms . We assessed synergy using the time-kill and checkerboard tests and compared the results to the E test method using 10 clinical isolates of A . baumannii . Antimicrobial combinations evaluated consisted of trovafloxacin or tobramycin in combination with cefepime or piperacillin . Synergy was detected with all combinations by either the checkerboard or time-kill method . Synergy was not detected by the Etest method . The agreement between the time-kill test and Etest method was 72% (range 42-97%); for the time-kill and checkerboard tests, agreement was 51% (range 30-67%) . The Etest method appears promising although further testing should be performed with additional antimicrobial agents and organisms.

J Med Microbiol, 2000 Oct, 49(10), 929 - 36
Distribution and in-vitro transfer of tetracycline resistance determinants in clinical and aquatic Acinetobacter strains; Guardabassi L et al.; Following characterisation by phenotypic tests and amplified ribosomal DNA restriction analysis (ARDRA), 50 tetracycline-resistant (MIC > or = 16 mg/L) Acinetobacter strains from clinical (n = 35) and aquatic (n = 15) samples were analysed by PCR for tetracycline resistance (Tet) determinants of classes A-E . All the clinical strains were A . baumannii; most (33 of 35) had Tet A (n = 16) or B (n = 17) determinants, and only two did not yield amplicons with primers for any of the five tetracycline resistance determinants . The aquatic strains belonged to genomic species other than A . baumannii, and most (12 of 15) did not contain determinants Tet A-E . Strains negative for Tet A-E were also negative for Tet G and M; further analysis of two aquatic strains with specific primers for Tet O and Tet Y and degenerate primers for Tet M-S-O-P(B)-Q also showed negative results . Transfer of tetracycline resistance was tested for 20 strains with three aquatic Acinetobacter strains and Escherichia coli K-12 as recipients . Transfer of resistance was demonstrated between aquatic strains from distinct ecological niches, but not from clinical to aquatic strains, nor from any Acinetobacter strain to E . coli K-12 . Most transconjugants acquired multiple relatively small plasmids (<36 kb) . Transfer did not occur when DNA from the donor strains was added to the recipient cultures and was not affected by deoxyribonuclease I, suggesting a conjugative mechanism . It is concluded that Tet A and B are widespread among tetracycline-resistant A . baumannii strains of clinical origin, but unknown genetic determinants are responsible for most tetracycline resistance among aquatic Acinetobacter spp . These differences, together with the inability of clinical strains to transfer tetracycline resistance in vitro to aquatic strains, contra-indicate any important flow of tetracycline resistance genes between clinical and aquatic acinetobacter populations.

Southeast Asian J Trop Med Public Health, 2000 Mar, 31(1), 96 - 103
Development of EIA for detection of Chlamydia trachomatis in genital specimens; Chomvarin C et al.; A double antibody sandwich enzyme immunoassay (EIA) for chlamydial antigen detection was developed using a monoclonal antibody against lipopolysaccharide (LPS) of Chlamydia trachomatis as a coating antibody . Polyclonal rabbit antiserum against partially purified antigen from elementary body (EB) antibody and horse-radish peroxidase conjugated goat anti-rabbit antibody were used as the primary and secondary antibody respectively . The developed EIA could detect protein of partially purified EB at the lowest concentration of 250 ng/ml . The assay was evaluated against the cell culture (CC), DNA hybridization assay (PACE2 system: Gen-Probe, San Diego, CA, USA) and a commercial enzyme immunoassay (kEIA) (Bioquest, NSW, Australia) . The sensitivity, specificity, positive and negative predictive values of the developed EIA (dEIA) were 87, 96.2, 80, 97.7 for the specimens from females and 90.9, 90.7, 71.4, 97.5 for the specimens from males repectively . Cross reaction was not found with Escherichia coli, Acinetobacter anitratus, beta-Streptococcus group A, Enterobacter spp, Enterococcus, Lactobacillus spp, Neisseria spp, but it was found with Candida albicans and herpes simplex virus type 1 . The developed EIA can be applied successfully for both genders, particularly males . The cost per test is less than those for CC, kEIA and PACE2.

J Antimicrob Chemother, 2000 Oct, 46(4), 535 - 40
Evaluation of the Oxoid Aura image system for measuring zones of inhibition with the disc diffusion technique; Andrews JM et al.; In this study the Oxoid Aura image antibiotic sensitivity test system, used as a stand-alone device, was compared with manual zone measurement and use of a template, for the determination of sensitivities . An overall correlation coefficient of 0.99 was observed for zone diameters measured using the Aura image system and zones measured manually, when the differences between zones were within 3 mm; 5.4% of zones showed a difference in zone diameter between manual and automated measurement of >3 mm . The results obtained using the template method for interpretation were less reliable than zone measurement, with cefuroxime and ampicillin tested against Enterobacteriaceae and Acinetobacter spp . When linked to a laboratory patient database, the bar code and disc identification facilities avoided errors that were associated with manual data entry.

Clin Infect Dis, 2000 Sep, 31(3), 690 - 7 Epub 2000 Oct 04.
Nosocomial bloodstream infections caused by Acinetobacter species in United States hospitals: clinical features, molecular epidemiology, and antimicrobial susceptibility; Wisplinghoff H et al.; We examined the clinical and epidemiological features of nosocomial bloodstream infections (BSIs) caused by Acinetobacter species and observed from 1 March 1995 through 28 February 1998 at 49 United States hospitals (SCOPE National Surveillance Program) . Acinetobacter species were found in 24 hospitals (49%) and accounted for 1.5% of all nosocomial BSIs reported . One hundred twenty-nine isolates were identified either as A . baumannii (n=111) or other Acinetobacter species (n=18) . Patients with A . baumannii BSI, compared with patients with nosocomial BSI caused by other gram-negative pathogens, were more frequently observed in the intensive care unit (69% vs . 47%, respectively; P<.001; odds ratio {OR} 2.4; 95% confidence interval {CI} 1.6-3.7) and were more frequently receiving mechanical ventilation (58% vs . 30%, respectively; P<.001; OR 3.2; 95% CI 2.1-4.8) . Crude mortality in patients with A . baumannii BSI was 32% . Molecular relatedness of strains was studied by use of polymerase chain reaction-based fingerprinting . Clonal spread of a single strain occurred in 5 hospitals . Interhospital spread of epidemic A . baumannii strains was not observed . The most active antimicrobial agents against A . baumannii (90% minimum inhibitory concentration values) were imipenem (1 mg/L; 100% of isolates susceptible), amikacin (8 mg/L; 96%), tobramycin (4 mg/L; 92%), and doxycycline (4 mg/L; 91%) . Thirty percent of isolates were resistant to > or =4 classes of antimicrobials and were considered to be multidrug resistant.

J Clin Microbiol, 2000 Oct, 38(10), 3636 - 45
Molecular surveillance of European quinolone-resistant clinical isolates of Pseudomonas aeruginosa and Acinetobacter spp . using automated ribotyping; Brisse S et al.; Nosocomial isolates of Pseudomonas aeruginosa and Acinetobacter spp . exhibit high rates of resistance to antibiotics and are often multidrug resistant . In a previous study (D . Milatovic, A . Fluit, S . Brisse, J . Verhoef, and F . J . Schmitz, Antimicrob . Agents Chemother . 44:1102-1107, 2000), isolates of these species that were resistant to sitafloxacin, a new advanced-generation fluoroquinolone with a high potency and a broad spectrum of antimicrobial activity, were found in high proportion in 23 European hospitals . Here, we investigate the clonal diversity of the 155 P . aeruginosa and 145 Acinetobacter spp . sitafloxacin-resistant isolates from that study by automated ribotyping . Numerous ribogroups (sets of isolates with indistinguishable ribotypes) were found among isolates of P . aeruginosa (n = 34) and Acinetobacter spp . (n = 16), but the majority of the isolates belonged to a limited number of major ribogroups . Sitafloxacin-resistant isolates (MICs > 2 mg/liter, used as a provisional breakpoint) showed increased concomitant resistance to piperacillin, piperacillin-tazobactam, ceftriaxone, ceftazidime, amikacin, gentamicin, and imipenem . The major ribogroups were repeatedly found in isolates from several European hospitals; these isolates showed higher levels of resistance to gentamicin and imipenem, and some of them appeared to correspond to previously described multidrug-resistant international clones of P . aeruginosa (serotype O:12) and Acinetobacter baumannii (clones I and II) . Automated ribotyping, when used in combination with more discriminatory typing methods, may be a convenient library typing system for monitoring future epidemiological dynamics of geographically widespread multidrug-resistant bacterial clones.

J Crit Care, 2000 Sep, 15(3), 85 - 90
The clinical features of severe community-acquired pneumonia presenting as septic shock . Norasept II Study Investigators; Marik PE; PURPOSE: The purpose of this article was to determine the outcome, clinical and prognostic features, and microbiology of a large group of patients with community-acquired pneumonia (CAP) presenting in septic shock . MATERIALS AND METHODS: The placebo limb of the Norasept II database was examined . Data were collected on patients in septic shock with a diagnosis of CAP who presented to a participating site from home . RESULTS: One hundred and forty-eight patients met the study criteria . The 28-day survival was 53% . One hundred and four pathogens were isolated from 77 (52%) patients with 24 (16%) patients having polymicrobial infections . The most common pathogen was Streptococcus pneumoniae (19%), followed by Staphylococcus aureus (18%), Haemophilus influenzae (14%), Klebsiella pneumoniae (11%), and Pseudomonas aeruginosa (7%) . Infection with P aeruginosa or Acinetobacter species carried a very high mortality (82%) . The only clinical variables recorded in the database that could identify patients with pseudomonas or acinetobacter infection was a history of alcohol abuse . Comorbidities were present in 74% of patients, involving predominantly the cardiorespiratory system . Logistic regression analysis demonstrated APACHE II score and serum interleukin 6 (IL-6) concentration to be significant independent predictors of mortality . Patients with pseudomonas or acinetobacter infection had significantly higher IL-6 levels and significantly lower tumor necrosis factor alpha levels when compared with the rest of the cohort of patients . CONCLUSION: A diverse spectrum of both gram-positive and gram-negative pathogens were implicated in patients with CAP presenting in septic shock, necessitating broad spectrum empiric antimicrobial coverage . This coverage should include antipseudomonal activity, particularly in alcoholic patients . Severity of illness (APACHE II score) and IL-6 levels were important prognostic factors . Infection with P aeruginosa and Acinetobacter species carried a very high mortality.

Vestn Otorinolaringol, 2000, (4), 26 - 9
{The study of aerobic bacterial background and antibiotic-sensitive isolated strains in the ENT department}; Poliakova TS et al.; Aerobic microbes in ENT departments were studied . The following strains were isolated: Staphylococcus, Streptococcus, Enterococcus, Acinetobacter, Klebsiella, Pseudomonas, Flavobacter, Citrobacter, Enterobacter, Escherichia, Aspergillus, Candida . 54.5% of the isolated strains were of hospital origin . Comparative evaluation of antibiotic resistance has shown a wide spectrum of resistance of the isolated microorganisms to antimicrobial drugs, among those to the drugs used in the ENT departments.

Infect Control Hosp Epidemiol, 2000 Sep, 21(9), 597 - 9
Investigation of an outbreak of gram-negative bacteremia among hematology-oncology outpatients; Penzak SR et al.; OBJECTIVE: To identify risk factors associated with an outbreak of gram-negative bacteremia (GNB) . SETTING: A university hospital . PATIENTS: Hematology-oncology outpatients . DESIGN: Retrospective case-control study . RESULTS: Thirty-eight patients developed GNB; 13 patients experienced more than one episode, and eight blood cultures grew more than one gram-negative organism . The most frequently isolated organisms were Stenotrophomonas maltophilia, Klebsiella pneumoniae, Acinetobacter baumannii, and Acinetobacter johnsonii . When the GNB patients (cases) were compared with randomly selected hematology-oncology patients (controls), central venous catheter (CVC) self-care (71% vs 39%; P=.02), and duration of recent hospital stay (median, 15 vs 4 days; P=.01) were identified as risk factors . In a logistic regression model, duration of recent hospital stay was the only risk factor significantly associated with GNB (odds ratio, 1.05; 95% confidence interval, 1.01-1.08; P<.02) . CONCLUSIONS: Hematology-oncology patients providing their own CVC care who have recently been hospitalized for more than 2 weeks may be at increased risk of GNB . CVCs should be protected from possible environmental contamination in hematologyoncology patients . Patients providing their own CVC care should undergo continued rigorous education regarding proper CVC care.

Infect Control Hosp Epidemiol, 2000 Sep, 21(9), 588 - 91
An outbreak of Acinetobacter baumannii: the importance of cross-transmission; D'Agata EM et al.; OBJECTIVE: To investigate an outbreak of nosocomial infections due to multidrug-resistant (MDR) Acinetobacter baumannii and to analyze the contribution of cross-transmission in the rise in infection rates . DESIGN: Epidemiological investigation; molecular typing using pulsed-field gel electrophoresis (PFGE); matched case-control study to identify risk factors for infection . SETTNG: A 34-bed surgical intensive care unit at a tertiary-care hospital . PATIENTS: Eighteen patients who developed MDRA baumannii nosocomial infection were matched to 36 patients who were admitted to the same surgical intensive care unit (SICU) room and did not develop an infection during the outbreak period . RESULTS: Prior to the outbreak, the baseline attack rate of MDR A baumannii nosocomial infections was 3 per 100 patients per month . From February 1 through March 22, 1998, the attack rate rose to 16 per 100 patients per month, with a total of 18 infections . All isolates had indistinguishable PFGE patterns . Seventy environmental cultures were negative for MDR A baumannii . Following intense infection control education, the attack rate decreased to 4 per 100 patients per month . By conditional logistic regression, cases were exposed to a significantly higher number of patients with MDR A baumannii infections compared to controls (odds ratio, 1.1; 95% confidence interval, 1.01-1.2; P=.02), even after adjusting for length of SICU admission and exposure to antibiotics and invasive devices . CONCLUSION: Cross-transmission between patients contributed to the rise in rates of MDRA baumannii infections . A common environmental source was not detected.

Folia Microbiol (Praha), 1999, 44(5), 553 - 6
Utilization of cyclohexanol by bacteria in a tropical estuarine water; Ilori MO; The Lagos lagoon is a wide expanse of estuarine water . The range of temperature, pH and conductivity of samples collected from 3 sources were 27-30 degrees C, 7.8-8.3 and 2.34-2.85 mS respectively . Consistent increase and decrease in the population of indigenous bacteria occurred in the test and control experiments respectively . Organisms in samples from Apapa and Iddo utilized cyclohexanol better than those in the sample from the University of Lagos . The cyclohexanol degrading bacteria were identified as species of Pseudomonas . Acinetobacter, Vibrio, Micrococcus and Flavobacterium . Pseudomonas sp . had the highest growth potential on cyclohexanol . These organisms play important roles in reducing the pollutant loads of the Lagos lagoon.

Antimicrob Agents Chemother, 2000 Oct, 44(10), 2684 - 8
Molecular characterization of integrons in Acinetobacter baumannii: description of a hybrid class 2 integron; Ploy MC et al.; Twenty Acinetobacter baumannii strains resistant to various antibiotics were analyzed for integron content and sequences of the amplification products . Sixteen clinical isolates had a class 1 integron, 2 contained an additional class 1 or class 2 integron, but no class 3 integron was detected . Thirteen strains had integrons with a single cassette: aac(3)-Ia (9 strains), ant(2")-Ia (2 strains), or aac(6')-Ib (2 strains); 1 had aac(6')-Ib and oxa20 cassettes and an unknown gene; and 1 had an integron containing ant(2")-Ia and an oxa3 cassette truncated by IS6100 . The remaining strains harbored class 1 integrons with gene cassettes previously found in Enterobacteriaceae . One integron had a hybrid structure composed of intI2 and the 3' conserved segment of class 1 integrons . These data indicate that integrons play a major role in multidrug resistance in Acinetobacter.

Am J Respir Crit Care Med, 2000 Sep, 162(3 Pt 1), 837 - 43
Rotation and restricted use of antibiotics in a medical intensive care unit . Impact on the incidence of ventilator-associated pneumonia caused by antibiotic-resistant gram-negative bacteria; Gruson D et al.; To test the hypothesis that a new program of antibiotic strategy control can minimize the incidence of ventilator-associated pneumonia (VAP) caused by potentially antibiotic-resistant microorganisms, we performed a prospective before-after study in 3, 455 patients admitted to a single intensive care unit over a 4-yr period . Regarding the bacterial ecology and the increasing antimicrobial resistance in our medical intensive care unit (MICU), we decided to vary our choice of empiric and therapeutic antibiotic treatment, with a supervised rotation, and a restricted use of ceftazidime and ciprofloxacin, which were widely prescribed before this scheduled change . For all patients, VAP was diagnosed based on the results of quantitative culture of bronchoalveolar lavage specimens (>/= 10(4) cfu/ml) . We studied 1,044 and 1,022 patients requiring more than 48 h of mechanical ventilation (MV), respectively, in the before-period (2 yr: 1995-1996) and the after-period (2 yr: 1997-1998) . We observed a decrease from 231 consecutive episodes of VAP in the before-period to 161 episodes of VAP in the after-period (p < 0.01), particularly for VAP occurring before 7 d of MV . The total number of potentially antibiotic-resistant gram-negative bacilli responsible for VAP such as Pseudomonas aeruginosa, Burkholderia cepacia, Steno-trophomonas maltophilia, and Acinetobacter baumanii decreased from 140 to 79 isolated bacilli . The susceptibilities of these bacteria to the antibiotics regimen increased significantly, especially for P . aeruginosa and B . cepacia . The percentage of methicillin-sensitive Staphylococcus aureus increased significantly from 40% to 60% of S . aureus responsible for VAP . These results suggest that a new strategy of antibiotics use could be an efficient means to reduce the incidence of VAP caused by antibiotic-resistant bacteria . Nevertheless, further studies are needed to validate these data.

J Clin Microbiol, 2000 Sep, 38(9), 3505 - 7
Pseudo-outbreak of imipenem-resistant Acinetobacter baumannii resulting from false susceptibility testing by a rapid automated system; Tsakris A et al.; Introduction of the Vitek GNS-506 susceptibility testing cards in the Hippokration General Hospital, Thessaloniki, Greece, resulted in an apparently high prevalence of imipenem-resistant Acinetobacter baumannii . When 35 of these isolates were further tested by disk diffusion, broth microdilution, and agar dilution assays, 32 were imipenem sensitive by all tests and three were sensitive or intermediate, depending on the method . The pseudoresistant acinetobacters did not form a genetically homogeneous group . It is suggested that the detection of imipenem-resistant A . baumannii isolates by this system should be confirmed by an additional susceptibility test.

J Clin Microbiol, 2000 Sep, 38(9), 3299 - 305
Characterization of a nosocomial outbreak caused by a multiresistant Acinetobacter baumannii strain with a carbapenem-hydrolyzing enzyme: high-level carbapenem resistance in A . baumannii is not due solely to the presence of beta-lactamases; Bou G et al.; From February to November 1997, 29 inpatients at Ramon y Cajal Hospital, Madrid, Spain, were determined to be either colonized or infected with imipenem- and meropenem-resistant Acinetobacter baumannii (IMRAB) strains (MICs, 128 to 256 microg/ml) . A wide antibiotic multiresistance profile was observed with IMRAB strains . For typing IMRAB isolates, pulsed-field gel electrophoresis was used . For comparative purposes, 30 imipenem- and meropenem-susceptible A . baumannii (IMSAB) strains isolated before, during, and after the outbreak were included in this study . The molecular-typing results showed that the outbreak was caused by a single IMRAB strain (genotype A) . By cloning experiments we identified a class D beta-lactamase (OXA-24) encoded in the chromosomal DNA of this IMRAB strain which showed carbapenem hydrolysis . Moreover, the outer membrane profile of the IMRAB strain showed a reduction in the expression of two porins at 22 and 33 kDa when compared with genetically related IMSAB isolates . In addition no efflux mechanisms were identified in the IMRAB strains . In summary, we report here the molecular characterization of a nosocomial outbreak caused by one multiresistant A . baumannii epidemic strain that harbors a carbapenem-hydrolyzing enzyme . Although alterations in the penicillin-binding proteins cannot be ruled out, the reduction in the expression of two porins and the presence of this OXA-derived beta-lactamase are involved in the carbapenem resistance of the epidemic nosocomial IMRAB strain.

Anesthesiology, 2000 Sep, 93(3), 638 - 45
Risk factors for early-onset, ventilator-associated pneumonia in critical care patients: selected multiresistant versus nonresistant bacteria; Akca O et al.; BACKGROUND: Ventilator-associated pneumonia is the leading nosocomial infection in critically ill patients . The frequency of ventilator-associated pneumonia caused by multidrug-resistant bacteria has increased in recent years, and these pathogens cause most of the deaths attributable to pneumonia . The authors, therefore, evaluated factors associated with selected multidrug-resistant ventilator-associated pneumonia in critical care patients . METHODS: The authors prospectively recorded potential risk factors at the time of intensive care unit admission . An endotracheal aspirate was obtained in all patients who met clinical criteria for pneumonia . Patients were considered to have ventilator-associated pneumonia only when they met the clinical criteria and aspirate culture was positive for bacteria 48 h or more after initiation of mechanical ventilation . Pediatric patients were excluded . Adult patients with ventilator-associated pneumonia were first grouped as "early-onset" (< 5 days) and "late-onset," determined by episodes of ventilator-associated pneumonia, and then, assigned to four groups based on the bacteria cultured from their tracheal aspirates: Pseudomonas aeruginosa, Acinetobacter baumanii, methicillin-resistant staphylococci, and all others . The first three bacteria were considered to be multidrug resistant, whereas the others were considered to be antibiotic susceptible . Potential risk factors were evaluated with use of univariate statistics and multivariate regression . RESULTS: Among 486 consecutive patients admitted during the study, 260 adults underwent mechanical ventilation for more than 48 h . Eighty-one patients (31%) experienced 99 episodes of ventilator-associated pneumonia, including Pseudomonas(33 episodes), methicillin-resistant staphylococci (17 episodes), Acinetobacter(9 episodes), and nonresistant bacteria (40 episodes) . Sixty-six of these episodes were early onset and 33 episodes were late onset . Logistic regression analysis identified three factors significantly associated with early-onset ventilator-associated pneumonia caused by any one of the multidrug-resistant bacterial strains: emergency intubation (odds ratio, 6.4; 95% confidence interval, 2.0-20.2), aspiration (odds ratio, 12.7; 95% confidence interval, 2.4-64.6), and Glasgow coma score of 9 or less (odds ratio, 3.9; 95% confidence interval, 1.3-11.3) . A . baumanii-related pneumonia cases were found to be significantly associated with two of these factors: aspiration (odds ratio, 14.2; 95% confidence interval, 1.5-133.8) and Glasgow coma score (odds ratio, 6.0; 95% confidence interval, 1.1-32.6) . CONCLUSIONS: The authors recommend that patients undergoing emergency intubation or aspiration or who have a Glasgow coma score of 9 or less be monitored especially closely for early-onset multidrug-resistant pneumonia . The occurrence of aspiration and a Glasgow coma score of 9 or less are especially associated with pneumonia caused by A . baumanii.

Eur J Clin Microbiol Infect Dis, 2000 Jul, 19(7), 501 - 5
Clinical and microbiological characteristics of bacteremia caused by Acinetobacter lwoffii; Ku SC et al.; A retrospective study was conducted to analyze the clinical features and pathogenic roles of bacteremia caused by Acinetobacter lwoffii during a 4-year period . Acinetobacter lwoffii (formerly Acinetobacter calcoaceticus var . lwoffii) is recognized as normal flora of the skin, oropharynx and perineum of healthy individuals . There are few reports of Acinetobacter lwoffii bacteremia associated with indwelling catheters in humans, particularly in immunocompromised hosts . The records of 18 patients with Acinetobacter lwoffii bacteremia whose underlying conditions included cancer (11 patients), systemic lupus erythematosus (n=1), chronic obstructive pulmonary disease (n = 2) and other diseases (n = 4), all but one of whom had indwelling catheters during the bacteremic episode, were examined . The clinical syndromes were classified as probable catheter-related bacteremia (n = 14), definite catheter-related bacteremia (n = 2), primary bacteremia (n = 1) or biliary tract infection (n = 1) . The infections improved after removal of the catheter and/or appropriate antimicrobial therapy . One death was attributable to the bacteremic event . The results of this study show that indwelling catheter-related Acinetobacter lwoffii bacteremia in immunocompromised hosts appears to be associated with a low risk of mortality.

Med J Malaysia, 1998 Mar, 53(1), 10 - 5
Bacterial infection of central venous catheters in short-term total parenteral nutrition; Chan L et al.; Fourteen severely ill ventilated patients in an intensive care unit, requiring short-term total parenteral nutrition, were examined for catheter-related infection . Microbiological analysis using Maki's SQ technique was carried out on catheter exit site, catheter hub, proximal subcutaneous segment of catheter and catheter up . Qualitative cultures were carried out on total parenteral nutrition and peripheral blood samples . Twenty six of 29 catheters removed (90%) were culture positive but only 7 catheters were related to positive blood cultures, giving a catheter-related bacteremia (CRB) rate of 24% . Haematogenous seeding was strongly implicated in 7/29 (24%) of catheters . Patients' skin flora appeared to be the main source of catheter-related infection . The organisms isolated for patients with CRB included coagulase-negative staphylococci, Acinetobacter and Klebsiella . It is suggested that to control infective complications of central venous catheters, emphasis should be focused on specialised intravenous therapy teams and the use of strict protocols for insertion and care of central lines.

Med J Malaysia, 1997 Dec, 52(4), 325 - 30
Post-caesarean septicaemia in Kandang Kerbau Hospital, Singapore, 1993-1995; Teo KP et al.; We reviewed all documented cases of septicaemia following caesarean deliveries in Kandang Kerbau Hospital between 1st January 1993 to 31st December 1995 . There were 22 cases of septicaemia among 8201 caesarean births, and hence the incidence is 2.7:1000 . There were 45,412 deliveries, and the overall caesarean section rate was 18.1% . Among the 22 documented cases of septicaemia which came under this study, the most common clinical conditions found were endomyometritis (7 cases), urinary tract infection (6 cases), and wound infection (3 cases) . One of the three cases with wound infection also had pneumonia . There was one patient who had mild transient myocarditis . We could not determine with certainty any site of infection in five patients . The most common bloodstream bacterial isolates was Staphylococcus aureus (16), while the uncommon ones were Acinetobacter baumanii (2), Escherichia coli (1), Klebsiella sp . (1), Staphylococcus epidermidis (1), Streptococcus Group F (1), Peptostreptococcus species and Veillonella species (1) . There was no mortality and prompt, vigorous treatment had led to uneventful recovery in all the cases.

Rev Soc Bras Med Trop, 2000 May-Jun, 33(3), 319 - 22
{Prevalence of microbiota in the digestive tract of wild females of Lutzomyia longipalpis Lutz & Neiva, 1912) (Diptera: Psychodidae)}; Oliveira SM et al.; We dissected the digestive tract of 245 females in pools of 35 flies forming 7 groups . These flies were Lutzomyia longipalpis originating from Lapinha Cave, Lagoa Santa, Minas Gerais . Out of the 8 species of bacteria isolated there was a predominancy of Gram negative bacterias (GNB) in the group of non-fermenters of sugar belonging to the following species: Acinetobacter lwoffii, Stenotrophomonas maltophilia, Pseudomonas putida and Flavimonas orizihabitans . The group of GNB fermenters were: Enterobacter cloacae and Klebsiella ozaenae . In the Gram positive group we isolated the genera Bacillus thuringiensis and Staphylococcus spp.

J Med Microbiol, 2000 Sep, 49(9), 773 - 8
Simplified phenotypic tests for identification of Acinetobacter spp . and their antimicrobial susceptibility status; Prashanth K et al.; Acinetobacter spp . have been found to be responsible for an increasing number of nosocomial infections . During a 16-month period, 22 patients hospitalised mainly in the respiratory intensive care unit (RICU), paediatric and other medical wards were investigated either for infection or colonisation by Acinetobacter spp . Of the 45 isolates of Acinetobacter detected among the total of 425 non-fermenters encountered, 24 representative isolates were selected for extended phenotypic identification . Four environmental isolates were also included in the study . These 28 isolates were typed by biotyping and antibiotyping, which helped in delineating the Acinetobacter spp . into 12 phenotypes and two distinct antibiotypes respectively . A sudden increase of cases of acinetobacter infection suggested that three outbreaks during the study period were due to phenotypes 1 and 2 of A . calcoaceticus-A . baumannii complex (Acb) . Strains of Acb-complex showed multiple drug resistance and were sensitive only to netilmicin . A comparatively high proportion of resistance to amikacin (48%) was also detected among these strains by the agar dilution method . The RICU environment was recognised as an important reservoir for the resistant outbreak strain (Acb-1) which was probably leading to persistent colonisation and recurrent infections.

Pathol Biol (Paris), 2000 Jul, 48(6), 533 - 40
{Muco-cutaneous colonization and nosocomial infections caused by methicillin-resistant Staphylococcus aureus and Acinetobacter baumanii in intensive care patients}; Pasdeloup T et al.; This study was designed to assess the frequency and risk factors for colonization with MRSA and A . baumanii in the intensive care unit, and to analyse the relationship between colonization and infection with MRSA or A . baumanii . During a 24-day survey period, colonization was studied weekly with nasal, throat and digit skin swabs; nosocomial infections were routinely monitored according to CDC recommendations . Clinical data and invasive procedures were registered during a one-year non-epidemic period; 103 ICU patients hospitalized for more than 7 days were prospectively included . We investigated acquired colonization and nosocomial infection with SAMR or A . baumanii for 87 patients not colonized by SAMR or A . baumanii on admission . The colonization acquisition rate was 56% for MRSA and 27% for A . baumanii . Infection incidence (cases per 1,000 patient-days) was 6.46 for MRSA and 1.61 for A . baumanii . On univariate analysis, acquired MRSA colonization was associated with longer ICU stays, longer mechanical ventilation and longer central venous catheterization . Multivariate analysis only showed an association with longer ICU stay . Acquired A . baumanii colonization was associated with SAPSII, longer mechanical ventilation, and longer central venous catheterization in univariate analysis . Multivariate analysis only showed an association with SAPSII and longer mechanical ventilation . In this study, SAMR or A . baumanii infections were not associated with colonization or clinical setting or invasive procedures.

Cent Eur J Public Health, 2000 Aug, 8(3), 164 - 6
Influence of some antibiotics on lipase and hydrophobicity of Acinetobacter baumannii; Hostacka A; Effect of four antibiotics (cefotaxime, ceftazidime, cefepime and ofloxacin) at subinhibitory concentrations (sub-MICs) (1/4, 1/8 or 1/16 of the MICs) on lipase and cell surface hydrophobicity of a clinical isolate of Acinetobacter baumannii 16265 was studied . Lipase activity in the majority of the cases was not significantly changed . Small alterations were drug and concentration dependent . The most efficient ceftazidime at 1/4 of the MIC reduced lipolytic activity to 78.7% of the control value . On the other hand, all beta-lactam antibiotics mainly at the highest concentration (1/4 of the MICs) most effectively decreased surface hydrophobicity of the studied strain . Hydrophobicity of treated bacteria evaluated by their adherence to xylene was in the range of 11.2 to 29.9% of the control values . The most efficient was cefepime . Whether the modifications in potential virulence factors of the bacteria tested observed in in-vitro experiments would have the clinical importance, remains to be evaluated.

Ceska Slov Farm, 2000 Jan, 49(1), 41 - 4
{Pharmacodynamic parameters of gentamicin and its effect on the surface hydrophobicity of Acinetobacter baumannii}; Hostacka A; The postantibiotic effect (PAE) and postantibiotic effect of subinhibitory concentration (PA SME) of gentamicin as well as influence of these pharmacodynamic parameters on surface hydrophobicity of three Acinetobacter baumannii strains were studied in vitro . Suppression of bacterial growth (PAE) after a short time exposure of bacteria to gentamicin (30 min) at suprainhibitory concentration 2x MIC was in the range of 0.6 h to 3.4 h . Longer PAE was observed after treatment of bacteria with gentamicin at 4x MIC (1.5 h-5.1 h) . Supra-subinhibitory concentrations of gentamicin (2x or 4x MIC + 0.2x MIC) caused still more effective delay of bacterial regrowth (PA SME) in comparison with suprainhibitory concentrations for one strain (9.1 h and 9.6 h) and in the case of further two strains they were so efficient that regrowth of bacteria was not observed for 24 h . Surface hydrophobicity of the gentamicin treated strains evaluated by adherence of bacteria to xylene ranged from 90.0% to 99.7% of the control values (without antibiotic).

Microbiol Res, 2000 Jul, 155(2), 95 - 100
Purification and characterization of lipase from psychrophilic Acinetobacter calcoaceticus LP009; Pratuangdejkul J et al.; A lipase-producing bacterium, Acinetobacter calcoacetius LP009, was isolated from raw milk . The optimum conditions for growth and lipase production by A . calcoaceticus LP009 were 15 degrees C with shaking at 200 rpm in LB supplemented with 1.0% (v/v) Tween 80 . The crude lipase was purified to homogeneous state by ultrafiltration and gel filtration chromatography on Sephadex G-100 . Its molecular weight determined by SDS-PAGE was 23 kDa and it exhibited maximum activity at pH 7.0 and 50 degrees C . It was stable over the pH range of 4.0 to 8.0 and at temperatures lower than 45 degrees C . It was a metalloenzyme that is positionally non-specific and had the ability to improve fat hydrolysis in soybean meal and in premixed animals feed.

J Chemother, 2000 Aug, 12(4), 294 - 8
Antimicrobial resistance of gram-negative isolates from intensive care units in Turkey: comparison to previous three years; Yucesoy M et al.; Resistance rates to selected antibiotics of gram-negative bacteria isolated from intensive care units (ICU) of 16 Turkish hospitals during 1998 were evaluated and compared to data from the previous 3 years . Antibiotic susceptibilities to imipenem, ceftazidime, ceftazidime-clavulanate, cefoperazone-sulbactam, ceftriaxone, cefepime, cefodizime, cefuroxime, piperacillin-tazobactam, ticarcillin-clavulanate, gentamicin, amikacin and ciprofloxacin were determined by Etest . A total of 1,404 isolates from 1,060 patients were collected, mainly from urinary and respiratory tracts . As in the previous 3 years, Pseudomonas spp . was the most frequently isolated gram-negative species (29.7%), followed by Escherichia coli, Acinetobacter and Klebsiella spp . Imipenem was the most active in vitro agent (73.4% susceptible), followed by ciprofloxacin (60.6%), cefoperazone-sulbactam (58.7%), cefepime (56.7%), piperacillin-tazobactam (55.0%) and amikacin (54.7%) . In 1996, a decline in susceptibility rates of all antibiotics was evident . With the exception of imipenem, resistance to which remained stable, rates somewhat increased in 1997 . In 1998, susceptibility to imipenem and cefepime remained stable, amikacin resistance tended to increase and susceptibility rates to other antibacterials showed a favorable increase . These results may in part be due to the implementation of a surveillance program and increased understanding of the magnitude of the resistance problem.

Appl Biochem Biotechnol, 2000 May, 87(2), 73 - 80
Semicontinuous production of lipase by Acinetobacter radioresistens in presence of nonwoven fabric; Li SC et al.; The effect of a hydrophobic nonwoven fabric on the lipase production by Acinetobacter radioresistens was investigated with semicontinuous culture . The fermentation medium contained n-hexadecane as the carbon source . The nonwoven fabric was made from nylon 6 and coated with an acrylic resin . Equipping the nonwoven fabric around the baffles of a 2.5-L agitated fermentor could provide a fine dispersion of n-hexadecane, thus enhancing lipase production . The improvement on lipase yield by using the nonwoven fabric was found to be comparable to that of using an emulsifier (gum arabic) . Compared with the corresponding culture in the absence of nonwoven fabric, the employment of the nonwoven fabric could significantly enhance both lipase yield and volumetric productivity.

Eur J Clin Microbiol Infect Dis, 2000 Jun, 19(6), 460 - 3
Analysis of risk factors for ventilator-associated pneumonia in a multidisciplinary intensive care unit; Sofianou DC et al.; A prospective study was conducted to determine the incidence, risk factors and pathogens of ventilator-associated pneumonia (VAP) in 198 patients requiring mechanical ventilation for more than 48 hours . VAP occurred in 67 (33.8%) patients . Risk factors associated with VAP were admission APACHE II score >20 (odds ratio {OR} 4.77, 95% confidence interval {CI} 2.04-11.27, P<0.001), mechanical ventilation > 10 days (OR 44.4, 95% CI 2.16-26.7, P< 0.0001), ICU length of stay >10 days (OR 9.4, 95% CI 3.55-25.65, P< 0.0001), and admission PaO2/FiO2 ratio <200mmHg (OR 3.4, 95% CI 1.00-11.41, P<0.05) . Logistic regression analysis showed a relationship between VAP and length of stay in ICU, duration of fever and presence of catheter-related infection . The pathogens isolated were predominantly gram-negative bacteria (83.2%), with a high proportion of Acinetobacter spp . (35%) resistant to commonly used antimicrobial agents . The mortality rate was not influenced by VAP.

J Bacteriol, 2000 Sep, 182(17), 4744 - 51
Genetic analysis of a gene cluster for cyclohexanol oxidation in Acinetobacter sp . Strain SE19 by in vitro transposition; Cheng Q et al.; Biological oxidation of cyclic alcohols normally results in formation of the corresponding dicarboxylic acids, which are further metabolized and enter the central carbon metabolism in the cell . We isolated an Acinetobacter sp . from an industrial wastewater bioreactor that utilized cyclohexanol as a sole carbon source . A cosmid library was constructed from Acinetobacter sp . strain SE19, and oxidation of cyclohexanol to adipic acid was demonstrated in recombinant Escherichia coli carrying a SE19 DNA segment . A region that was essential for cyclohexanol oxidation was localized to a 14-kb fragment on the cosmid DNA . Several putative open reading frames (ORFs) that were expected to encode enzymes catalyzing the conversion of cyclohexanol to adipic acid were identified . Whereas one ORF showed high homology to cyclohexanone monooxygenase from Acinetobacter sp . strain NCIB 9871, most of the ORFs showed only moderate homology to proteins in GenBank . In order to assign functions of the various ORFs, in vitro transposon mutagenesis was performed using the cosmid DNA as a target . A set of transposon mutants with a single insertion in each of the ORFs was screened for cyclohexanol oxidation in E . coli . Several of the transposon mutants accumulated a variety of cyclohexanol oxidation intermediates . The in vitro transposon mutagenesis technique was shown to be a powerful tool for rapidly assigning gene functions to all ORFs in the pathway.

Rev Latinoam Microbiol, 1999 Oct-Dec, 41(4), 279 - 84
{Non-fermenting Gram-negative bacilli: distribution in clinical specimens and antimicrobial susceptibility}; Merino LA et al.; In the present work was studied the prevalence, distribution in clinical specimens, and antimicrobial susceptibility of non-fermentative Gram-negative bacilli (NFGNB) from patients attended at Hospital "Angela I . de Llano" (Corrientes, Argentina) . A total of 125 strains of NFGNB were recovered from various clinical specimens from July, 1997 to December, 1998 . Isolates were identified by classical biochemical tests . Drug sensitivity was performed by standard methods with cefotaxime (CTX), ceftazidime (CAZ), piperacillin (PIP), ampicillin-sulbactam (AMS), piperacillin/tazobactam (TAZ), imipenem (IMP), amikacin (AKN), gentamicin (GEN) and ciprofloxacin (CIP) . The most common isolates were Pseudomonas aeruginosa (48.8%); Acinetobacter baumannii (16.8%), Acinetobacter spp . (6.4%), Chryseobacterium spp . (5.6%), Stenotrophomonas maltophilia (4%), and others (18.4%) . Most of them were recovered from respiratory secretions (36.0%), and urine (26.4%) . IMP was the most effective antimicrobial . Many species of NFGNB showed resistance to several antibiotics tested (CTX, GEN, AMS, and CIP) . Due to multiresistance found by more prevalent NFGNB, constant survey of antibacterial sensibility are essential for a correct control and management of nosocomial infections, and ambulatory patients with some risk factors.

Rev Latinoam Microbiol, 1998 Jul-Dec, 40(3-4), 142 - 50
Identification of bacteria in water for pharmaceutical use; Martino TK et al.; Different systems for the obtention of water used in Biopharmaceutical Industry were characterized from the bacteriological point of view . Determination of aerobic mesophilic microorganisms was performed; as well as the isolation of contaminant microorganisms for what the techniques of membrane filtration was used . For the identification of the more representative species there were made conventional biochemical tests and quick systems: API . The results show that water serving as tap water for purification systems fulfill with the microbiological requirements to this kind of water . All the isolated microorganisms were gram-negative bacteria characteristics of this environment: Pseudomonas putida, Xanthomonas maltophilia, Aeromonas salmonicida ssp . salmonicida, Flavimonas coryzihabitans and Acinetobacter iwoffi . The ultrafiltration and distillation tested systems fulfill with the established microbiological limits, except for deionization and distilled water storing systems . The isolation showed that approximately the 76.9% were of Gram-negative bacteria, the 14.6% of Gram-positive cocci and the 8.5% Gram-positive sporulated bacilli . The most representative genus of purified water were: Pseudomonas, with the higher percent of incidence, Staphylococcus, Bacillus, Flavobacterium, Sphingomonas, Aeromonas and Agrobacterium.

Biochemistry, 2000 Aug 8, 39(31), 9384 - 92
Ca2+-assisted, direct hydride transfer, and rate-determining tautomerization of C5-reduced PQQ to PQQH2, in the oxidation of beta-D-glucose by soluble, quinoprotein glucose dehydrogenase; Dewanti AR et al.; Spectral and kinetic studies were performed on enzyme forms of soluble glucose dehydrogenase of the bacterium Acinetobacter calcoaceticus (sGDH) in which the PQQ-activating Ca(2+) was absent (Holo X) or was replaced with Ba(2+) (Ba-E) or in which PQQ was replaced with an analogue or a derivative called "nitroPQQ" (E-NPQ) . Although exhibiting diminished rates, just like sGDH, all enzyme forms were able to oxidize a broad spectrum of aldose sugars, and their reduced forms could be oxidized with the usual artificial electron acceptor . On inspection of the plots for the reductive half-reaction, it appeared that the enzyme forms exhibited a negative cooperativity effect similar to that of sGDH itself under turnover conditions, supporting the view that simultaneous binding of substrate to the two subunits of sGDH causes the effect . Stopped-flow spectroscopy of the reductive half-reaction of Ba-E with glucose showed a fluorescing transient previously observed in the reaction of sGDH with glucose-1-d, whereas no intermediate was detected at all in the reactions of E-NPQ and Holo X . Using hydrazine as a probe, the fluorescing C5 adduct of PQQ and hydrazine was formed in sGDH, Ba-E, and Holo X, but E-NPQ did not react with hydrazine . When this is combined with other properties of E-NPQ and the behavior of enzyme forms containing a PQQ analogue, we concluded that the catalytic potential of the cofactor in the enzyme is not determined by its adduct-forming ability but by whether it is or can be activated with Ca(2+), activation being reflected by the large red shift of the absorption maximum induced by this metal ion when binding to the reduced cofactor in the enzyme . This conclusion, together with the observed deuterium kinetic isotope effect of 7.8 on transient formation in Ba-E, and that already known on transient decay, indicate that the sequential steps in the mechanism of sGDH must be (1) reversible substrate binding, (2) direct transfer of a hydride ion (reversible or irreversible) from the C1 position of the beta-anomer of glucose to the C5 of PQQ, (3) irreversible, rate-determining tautomerization of the fluorescing, C5-reduced PQQ to PQQH(2) and release (or earlier) of the product, D-glucono-delta-lactone, and (4) oxidation of PQQH(2) by an electron acceptor . The PQQ-activating Ca(2+) greatly facilitates the reactions occurring in step 2 . His144 may also play a role in this by acting as a general base catalyst, initiating hydride transfer by abstracting a proton from the anomeric OH group of glucose . The validity of the proposed mechanism is discussed for other PQQ-containing dehydrogenases.

Appl Environ Microbiol, 2000 Aug, 66(8), 3556 - 65
Effect of field inoculation with Sinorhizobium meliloti L33 on the composition of bacterial communities in rhizospheres of a target plant (Medicago sativa) and a non-target plant (Chenopodium album)-linking of 16S rRNA gene-based single-strand conformation polymorphism community profiles to the diversity of cultivated bacteria; Schwieger F et al.; Fourteen weeks after field release of luciferase gene-tagged Sinorhizobium meliloti L33 in field plots seeded with Medicago sativa, we found that the inoculant also occurred in bulk soil from noninoculated control plots . In rhizospheres of M . sativa plants, S . meliloti L33 could be detected in noninoculated plots 12 weeks after inoculation, indicating that growth in the rhizosphere preceded spread into bulk soil . To determine whether inoculation affected bacterial diversity, 1,119 bacteria were isolated from the rhizospheres of M . sativa and Chenopodium album, which was the dominant weed in the field plots . Amplified ribosomal DNA restriction analysis (ARDRA) revealed plant-specific fragment size frequencies . Dominant ARDRA groups were identified by 16S rRNA gene nucleotide sequencing . Database comparisons indicated that the rhizospheres contained members of the Proteobacteria (alpha, beta, and gamma subgroups), members of the Cytophaga-Flavobacterium group, and gram-positive bacteria with high G+C DNA contents . The levels of many groups were affected by the plant species and, in the case of M . sativa, by inoculation . The most abundant isolates were related to Variovorax sp., Arthrobacter ramosus, and Acinetobacter calcoaceticus . In the rhizosphere of M . sativa, inoculation reduced the numbers of cells of A . calcoaceticus and members of the genus Pseudomonas and increased the number of rhizobia . Cultivation-independent PCR-single-strand conformation polymorphism (SSCP) profiles of a 16S rRNA gene region confirmed the existence of plant-specific rhizosphere communities and the effect of the inoculant . All dominant ARDRA groups except Variovorax species could be detected . On the other hand, the SSCP profiles revealed products which could not be assigned to the dominant cultured isolates, indicating that the bacterial diversity was greater than the diversity suggested by cultivation.

Appl Environ Microbiol, 2000 Aug, 66(8), 3481 - 6
Long-chain aldehyde dehydrogenase that participates in n-alkane utilization and wax ester synthesis in Acinetobacter sp . strain M-1; Ishige T et al.; A long-chain aldehyde dehydrogenase, Ald1, was found in a soluble fraction of Acinetobacter sp . strain M-1 cells grown on n-hexadecane as a sole carbon source . The gene (ald1) was cloned from the chromosomal DNA of the bacterium . The open reading frame of ald1 was 1,512 bp long, corresponding to a protein of 503 amino acid residues (molecular mass, 55,496 Da), and the deduced amino acid sequence showed high similarity to those of various aldehyde dehydrogenases . The ald1 gene was stably expressed in Escherichia coli, and the gene product (recombinant Ald1 {rAld1}) was purified to apparent homogeneity by gel electrophoresis . rAld1 showed enzyme activity toward n-alkanals (C(4) to C(14)), with a preference for longer carbon chains within the tested range; the highest activity was obtained with tetradecanal . The ald1 gene was disrupted by homologous recombination on the Acinetobacter genome . Although the ald1 disruptant (ald1Delta) strain still had the ability to grow on n-hexadecane to some extent, its aldehyde dehydrogenase activity toward n-tetradecanal was reduced to half the level of the wild-type strain . Under nitrogen-limiting conditions, the accumulation of intracellular wax esters in the ald1Delta strain became much lower than that in the wild-type strain . These and other results imply that a soluble long-chain aldehyde dehydrogenase indeed plays important roles both in growth on n-alkane and in wax ester formation in Acinetobacter sp . strain M-1.

J Microbiol Immunol Infect, 2000 Jun, 33(2), 123 - 6
Comparison of colony lift with direct spotting methods of blot preparation on the effect of colony hybridization in the detection of environmental organisms; Hu TL et al.; Nucleic acid probes are used on site to detect or to identify individual microbial cells without cultivation . This molecular technique can avoid some limitations of traditional identification methods including time consuming and imprecise . This study examined the factors affecting colony hybridization and compared the effectiveness of membrane prepared by colony lifting with direct spotting procedures using the universal probe Eub 338 . The results of hybridization varied depending on the type of colony morphology . For dry and rough colonies, colony hybridization was not suitable for detecting Acinetobactersp . (CK2A, CK2B), Alcaligenes sp . (TH11 B), Xanthomonas sp . (TH7B), Arthrobacter globiformis (CCRC 10598) and Microbacterium sp . (CCRC 11036) . Colonies of Acinetobacter sp . (CCRC 15425) and Alcaligenes spp . (CCRC 10828, H) on agar and membrane were thick and raised, and their detection signals of hybridization were diffused or blank . Colonies of Alcaligenes sp . (CM7A, ANV2) and Acinetobacter sp . (ANV8) isolated from the sludge of biological processes treating ABS wastewater were flat and smooth, and their hybridization signals were clear . For those strains suitable for colony hybridization, the colony blots prepared by colony lift and direct spotting procedures gave the same sensitivity for colony hybridization.

J Microbiol Immunol Infect, 2000 Jun, 33(2), 109 - 14
Efficacy and safety of cefepime in the treatment of serious bacterial infections in hospitalized adult patients; Sheng WH et al.; Proper and timely choice of the antibiotic therapy for the management of infection in hospitalized patients is an immense challenge to the clinician . A newly developed extended-spectrum fourth-generation cephalosporin cefepime, has been shown to have good activity against both gram-positive and gram-negative organisms . In order to further establish the efficacy and safety of cefepime in the treatment of adult hospitalized patients in Taiwan, we reviewed the medical records of all patients who received cefepime therapy for more than 72 h at the National Taiwan University Hospital during the period from January 1999 to April 1999 . A total of 55 patients were treated with cefepime during this period . Thirty-two of them were males and 23 were females . Their ages ranged from 16 to 94 years old (average, 67) . All had severe infections with a mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score of 18 . More than half (56%) of the infections were nosocomial . The most common infections included pulmonary infection (49%), intra-abdominal infection (27%), skin and soft tissue infection (15%), febrile neutropenia (7%), and intravascular device infection (5%) . All but one of the patients (98%) had pre-existing medical disease . Malignancy (49%) was the most common underlying illness . Pseudomonas aeruginosa (23 isolates) and Enterobacter cloacae (21) were the most common pathogens causing infections . Thirty-one (58%) of the patients were effectively treated with cefepime . Twenty of the patients died during the study period with most deaths attributable to persistent microbial infection and superinfection, especially Acinetobacter baumannii and fungal infection . Adverse effects developed in six patients, including eosinophilia (3 patients), leukopenia (2), skin rash (1), and drug related fever (1), but all were mild and transient . The results of this study show that cefepime is a safe and effective agent in the treatment of adult patients with severe infection in Taiwan.

Clin Infect Dis, 2000 Jul, 31(1), 101 - 6 Epub 2000 Jul 17.
Endemic carbapenem-resistant Acinetobacter species in Brooklyn, New York: citywide prevalence, interinstitutional spread, and relation to antibiotic usage; Manikal VM et al.; Acinetobacter species are problematic nosocomial pathogens . In November 1997, pathogens isolated by microbiology laboratories were collected from 15 hospitals in Brooklyn, New York . Acinetobacter species accounted for 10% of gram-negative isolates . Only half of Acinetobacter species were susceptible to carbapenems; 11 hospitals had at least 1 isolate resistant to carbapenems . Other Acinetobacter susceptibility rates were as follows: polymyxin, 99%; amikacin, 87%; ampicillin/sulbactam, 47%; ceftazidime, 25%; and ciprofloxacin 23% . Overall, 10% were resistant to all commonly used antibiotics . Genetic analysis by use of pulsed-field gel electrophoresis of 12 carbapenem-resistant isolates revealed 4 strains that were recovered from >1 hospital, which suggests interinstitutional spread . Antibiotic usage data from 11 hospitals revealed that the use of third-generation cephalosporins was associated significantly with the percentage of carbapenem-resistant strains (P=.03) . Resistant Acinetobacter species have become endemic in Brooklyn, New York . Citywide strategies that involve surveillance, infection-control practices, and the reduction of antibiotic usage may be necessary to control the spread of these pathogens.

Can J Microbiol, 1999 Oct, 45(10), 879 - 84
Diversity of culturable heterotrophic aerobic bacteria in pristine stream bed sediments; Halda-Alija L et al.; More than 900 culturable, heterotrophic aerobic isolates were obtained from the sediments of a forested, pristine stream and analyzed using three classical microbiological tests: API 20E, amplified ribosomal DNA restriction analysis (ARDRA), and fatty acid analysis . Gram-negative bacteria comprised most of the heterotrophic aerobic isolates (66.7%), similar to other oligotrophic environments . The isolates were assigned to the genus level as Pseudomonas, Flavobacterium, Micrococcus, Bacillus, Chromobacterium, Acinetobacter, Alcaligenes, Aeromonas, Methylobacterium, Enterobacter, Corynebacterium, and Sporolactobacillus . Genotypic analysis by ARDRA facilitated the comparison among strains within Pseudomonas, Bacillus, and Enterobacter groups . Temperature and predation may influence the survival of bacteria during seasons, as shown previously by others . Our results showed that the number of heterotrophic aerobic bacteria, especially Enterobacter, Alcaligenes, and Aeromonas, and Gram-positive bacteria, decreased in winter compared to summer conditions.

Can J Microbiol, 1999 Oct, 45(10), 826 - 32
Impact of an urban effluent on the bacterial community structure in the Arga River (Spain), with special reference to culturable gram-negative rods; Goni-Urriza M et al.; The Arga River is an interesting system in which to study the impact of urban effluent pollution because it receives a single effluent in the form of wastewater discharge from the city of Pamplona . To analyze the extent of this discharge, total bacteria, culturable heterotrophic bacteria, and Gram-negative heterotrophic bacteria were enumerated and 409 isolates of the latter were identified . One sampling station was located upstream from the inflow, while five were located up to 30 km downstream . Bacterial counts increased drastically downstream from the wastewater inflow . Total bacterial numbers decreased along the 30 km downstream, the last station attaining similar values to those recorded upstream from the discharge . However, culturable heterotrophic and Gram-negative heterotrophic bacteria levels generally remained significantly higher within the 30 km zone investigated . Among the 409 isolates identified, Aeromonas spp . were the most frequent both upstream and downstream from the discharge . In contrast, although strains belonging to different genera of Enterobacteriaceae were found in all stations, their occurrence was significantly higher just downstream from the polluted discharge . Acinetobacter spp., which were never found upstream, were detected in all stations below the discharge . Our results clearly show that the bacterial community structure changes definitively downstream from the discharge and that Aeromonas were common throughout the sampling zone . Thus they cannot be considered good indicators of pollution in this setting compared to some genera of Enterobacteriaceae or some species of Acinetobacter, the distribution of which correlated better with the distance from the wastewater discharge.

Diagn Microbiol Infect Dis, 2000 Jul, 37(3), 215 - 7
Corneal perforation due to Acinetobacter junii: a case report; Prashanth K et al.; Acinetobacter spp . is emerging as a common cause of nosocomial infections . Community acquired ocular infections due to Acinetobacter are rare . Only one case of perforation of cornea has been reported previously, where old nomenclature was used to describe the causal agent . We report a case of corneal perforation due to Acinetobacter junii for which a therapeutic penetrating keratoplasty was conducted and the patient eventually recovered.

Antimicrob Agents Chemother, 2000 Aug, 44(8), 2211 - 3
Comparative activities of ciprofloxacin, clinafloxacin, gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, and trovafloxacin against epidemiologically defined Acinetobacter baumannii strains; Heinemann B et al.; In vitro activities of seven fluoroquinolones against 140 clinical Acinetobacter baumannii isolates representing 138 different strain types were determined . The rank order of activity was clinafloxacin > gatifloxacin > levofloxacin > trovafloxacin > gemifloxacin = moxifloxacin > ciprofloxacin . The 31 outbreak-related A . baumannii strains were significantly more resistant than were 109 sporadic strains.

Rev Esp Quimioter, 1999 Dec, 12(4), 325 - 31
{Should cefminox substitute cefoxitin in infections caused by bacteria susceptible to both drugs?}; Damaso D et al.; We studied the in vitro activity of cefminox (MIC by agar dilution) and cefoxitin against 477 facultative Gram-positive and Gram-negative isolates which were recovered from clinical specimens and identified by standard methods . Cefminox has proved to be 4-16 times more active than cefoxitin against enteric Gram-negative bacilli commonly involved in cholecystitis, secondary peritonitis, intraabdominal abscesses and gynecological infections . On the contrary, cefoxitin has proved to be four times more active against Gram-positive cocci . Both have been ineffective against Enterobacter spp., Pseudomonas aeruginosa and Acinetobacter spp . The microbiological activity and pharmacokinetic parameters of cefminox make it one of the first choice treatments for community-acquired intraabdominal and pelvic infections with the presence of anaerobes.

Biochemistry, 2000 Jul 11, 39(27), 7943 - 55
Structure of Acinetobacter strain ADP1 protocatechuate 3, 4-dioxygenase at 2.2 A resolution: implications for the mechanism of an intradiol dioxygenase; Vetting MW et al.; The crystal structures of protocatechuate 3,4-dioxygenase from the soil bacteria Acinetobacterstrain ADP1 (Ac 3,4-PCD) have been determined in space group I23 at pH 8.5 and 5.75 . In addition, the structures of Ac 3,4-PCD complexed with its substrate 3, 4-dihydroxybenzoic acid (PCA), the inhibitor 4-nitrocatechol (4-NC), or cyanide (CN(-)) have been solved using native phases . The overall tertiary and quaternary structures of Ac 3,4-PCD are similar to those of the same enzyme from Pseudomonas putida{Ohlendorf et al . (1994) J . Mol . Biol . 244, 586-608} . At pH 8.5, the catalytic non-heme Fe(3+) is coordinated by two axial ligands, Tyr447(OH) (147beta) and His460(N)(epsilon)(2) (160beta), and three equatorial ligands, Tyr408(OH) (108beta), His462(N)(epsilon)(2) (162beta), and a hydroxide ion (d(Fe-OH) = 1.91 A) in a distorted bipyramidal geometry . At pH 5.75, difference maps suggest a sulfate binds to the Fe(3+) in an equatorial position and the hydroxide is shifted {d(Fe-OH) = 2.3 A} yielding octahedral geometry for the active site Fe(3+) . This change in ligation geometry is concomitant with a shift in the optical absorbance spectrum of the enzyme from lambda(max) = 450 nm to lambda(max) = 520 nm . Binding of substrate or 4-NC to the Fe(3+) is bidentate with the axial ligand Tyr447(OH) (147beta) dissociating . The structure of the 4-NC complex supports the view that resonance delocalization of the positive character of the nitrogen prevents substrate activation . The cyanide complex confirms previous work that protocatechuate 3,4-dioxygenases have three coordination sites available for binding by exogenous substrates . A significant conformational change extending away from the active site is seen in all structures when compared to the native enzyme at pH 8.5 . This conformational change is discussed in its relevance to enhancing catalysis in protocatechuate 3,4-dioxygenases.

Rev Esp Quimioter, 1999, 12(4), 325 - 331
{Should cefminox substitute cefoxitin in infectionscaused by bacteria susceptible to both drugs?}; Damaso D et al.; We studied the in vitro activity of cefminox (MIC by agar dilution) and cefoxitin against 477 facultative Gram-positive and Gram-negative isolates which were recovered from clinical specimens and identified by standard methods . Cefminox has proved to be 4-16 times more active than cefoxitin against enteric Gram-negative bacilli commonly involved in cholecystitis, secondary peritonitis, intraabdominal abscesses and gynecological infections . On the contrary, cefoxitin has proved to be four times more active against Gram-positive cocci . Both have been ineffective against Enterobacter spp., Pseudomonas aeruginosa and Acinetobacter spp . The microbiological activity and pharmacokinetic parameters of cefminox make it one of the first choice treatments for community-acquired intraabdominal and pelvic infections with the presence of anaerobes.

Am J Surg, 2000 Feb 1, 179(2 Suppl 1), 2 - 7
Importance, morbidity, and mortality of pneumonia in the surgical intensive care unit; Barie PS; Surgical patients are at high risk to develop nosocomial pneumonia, although an accurate diagnosis is difficult to make . Staphylococcus aureus and Pseudomonas aeruginosa are the most common pathogens, but Acinetobacteris emerging as an important pathogen . Because affected patients are often critically ill with multisystem pathology, it can be difficult to ascribe morbidity or mortality directly to the infection.

Can J Microbiol, 2000 May, 46(5), 441 - 50
Community dynamics of a mixed-bacterial culture growing on petroleum hydrocarbons in batch culture; Van Hamme JD et al.; The effects of various hydrocarbon substrates, and a chemical surfactant capable of enhancing crude-oil biodegradation, on the community structure of a mixed-bacterial inoculum were examined in batch culture . Of 1000 TSA-culturable isolates, 68.6% were identified at the genus level or better by phospholipid fatty acid analysis over 7-day time course experiments . Cultures were exposed to 20 g/L Bow River crude oil with and without 0.625 g/L Igepal CO-630 (a nonylphenol ethoxylate surfactant), 5 g/L saturates, 5 g/L aromatics, or 125 g/L refinery sludge . A group of six genera dominated the cultures: Acinetobacter, Alcaligenes, Ochrobactrum, Pseudomonas/Flavimonas, Stenotrophomonas, and Yersinia . Species from four of the genera were shown to be capable of hydrocarbon degradation, and counts of hydrocarbon degrading and total heterotrophic bacteria over time were nearly identical . Pseudomonas/Flavimonas and Stenotrophomonas normally dominated during the early portions of cultures, although the lag phase of Stenotrophomonas appears to have been increased by surfactant addition . Acinetobacter calcoaceticus was the most frequently isolated microorganism during exposure to the saturate fraction of crude oil . Regardless of substrate, the culture medium supported a greater variety of organisms during the latter portions of cultures . Understanding the community structure and dynamics of mixed bacterial cultures involved in treatment of heterogeneous waste substrates may assist in process development and optimization studies.

J Clin Ultrasound, 2000 Jul-Aug, 28(6), 295 - 8
Assessment of condoms as probe covers for transvaginal sonography; Amis S et al.; PURPOSE: This prospective study assessed the incidence of transvaginal probe contamination and breakage of condoms used to cover those probes during transvaginal sonography . METHODS: Over a 9-month period, 214 women underwent transvaginal sonography with probes that had been coated with gel and then covered with a latex condom . Condom defects were detected after the scans by inspection, by adding hydrogen peroxide, and by filling the condoms with 500 ml of water . After the condoms were removed, the probe was either wiped with a dry tissue (during the first 18 weeks of the study) or wiped first with a dry tissue and then with a 70% isopropyl alcohol wipe . Probe head contamination was assessed by periodic swab sampling and culturing for bacteria and herpes simplex virus . Samples of the sonographic gel also were tested for bacterial contamination at approximately weekly intervals . RESULTS: A total of 217 condoms were used, 3 of which broke and were discarded while being applied to the probe . Two of the 214 condoms used (0.9%) were found upon visual inspection to have perforations . None of the other 212 condoms leaked upon being filled with water; none of the 204 condoms tested with hydrogen peroxide showed bubbles . Only 1 of the 46 probe swab samples was positive for bacteria (Acinetobacter species); none of the 26 probe swab samples cultured for viruses or the 25 gel samples cultured for bacteria were positive . CONCLUSIONS: Condoms used to cover transvaginal probes showed a low rate of perforation . Disinfection of the probe with isopropyl alcohol wipes further reduced the risk of contamination .

Med Dosw Mikrobiol, 1999, 51(1-2), 113 - 22
{Evaluation of resistance patterns of gram-negative rods from personal clinical materials}; Kedzierska J et al.; 1862 clinical specimens from neonates with infection risk factors treated in the Department of Neonatology, University of Cracow were examined . The aim of this study was to investigate the participation of clinically important Gram-negative rods in hospital infections and to check the resistance patterns of these pathogens . The strains were identified in automatic ATB system using ID 32E and ID 32GN strips with biochemical tests . The susceptibility of isolates of antibacterial agents was determined in automatic ATB system using ATB G- and ATB PSE strips . 436 strains of Gram-negative rods were cultured . 289 strains (66.3%) belonging to Entero-bacteriaceae family and 147 strains (33.7%) non-fermenting rods were isolated . Among Gram-negative aerobic fermenting rods (mainly K . pneumoniae and E . cloacae), increasing resistance to aminoglycosides and beta-lactams, due to new broad spectrum and so called inducible beta-lactamases, was observed . The contribution of non-fermenting rods, especially Pseudomonas spp . and Acinetobacter spp . to the aetiology of infections in hospitalized newborns has increased . Carbapenems and fluoroquinolones are highly active in vitro against the examined strains of multiresistant Gram-negative rods.

Diagn Microbiol Infect Dis, 2000 Jun, 37(2), 143 - 6
Cefditoren activity against nearly 1000 non-fastidious bacterial isolates and the development of in vitro susceptibility test methods; Jones RN et al.; Cefditoren (formerly ME-1206) is an investigational, orally administered cephalosporin ester with bactericidal activity against many Gram-positive and -negative organisms . Cefditoren potency against nearly 1000 non-fastidious species was determined by National Committee for Clinical Laboratory Standards (NCCLS) reference broth microdilution and standardized disk diffusion methods . Against staphylococci, usable cefditoren activity was completely correlated with oxacillin with respect to potency and susceptibility interpretation (mec A-negative strains) . Cefditoren was very active against Klebsiella spp., Proteus mirabilis, Salmonella spp., and Escherichia coli (MIC(90) range, 0.12-1 microg/ml; median zone, 23-26 mm) . Cefditoren had more limited activity against Citrobacter spp., Enterobacter spp., Serratia marcescens, and indole-positive Proteae (MIC(50) range, 0.12-1 microg/ml; MIC(90), > 16 microg/ml; median zone, 18-25 mm) . Against Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter spp., and other non-fermentors, cefditoren was inactive (MIC(90), > 16 microg/ml; zone, 6 mm) . Pharmacokinetic analysis of cefditoren showed that utilized dosages produce a plasma concentration that exceeds 0.5 microg/ml for 5 to 8 h and 1 microg/ml for 4 to 6 hours (T(1/2) ranges from 1.5-2 h) . The following interpretive criteria were suggested: </= 2 microg/ml or >/= 15 mm (susceptible) and >/= 8 microg/ml or </= 11 mm (resistance) that yielded an intermethod categorical agreement of 95.8% and very major or major error rates of 0.7% and 0.3%, respectively . Alternatively, </= 1 microg/ml or >/= 18 mm (susceptible) and >/= 4 microg/ml or </= 14 mm (resistant) breakpoints resulted in 96.2% accuracy and combined serious errors of only 1.1% . Cefditoren was observed to be a very active cephalosporin ranking among the most potent available orally active beta-lactams for use against a wide variety of pathogens.

Chemotherapy, 2000 Jul-Aug, 46(4), 282 - 92
Surveillance of nosocomial cross-infections due to three Acinetobacter genospecies (Acinetobacter baumannii, genospecies 3 and genospecies 13) during a 10-Year Observation period: serotyping, macrorestriction analysis of Genomic DNA and antibiotic susceptibilities; Traub WH et al.; During a 10-year surveillance period, a total of 2,359 isolates comprising the genus Acinetobacter were recovered and identified presumptively with phenotypic tests . Genospecies 3 was the most common (n = 1,053), followed by genospecies 13 (n = 352), Acinetobacter baumannii (n = 335), Acinetobacter Iwoffi (n = 162), and genospecies 14 (n = 97); 100 isolates (4.2%) were categorized as questionable Acinetobacter . There were 34 clusters of putative nosocomial cross-infection due either to genospecies 3 (n = 16), A . baumannii (n = 10) or genospecies 13 (n = 8) . Apart from 3 clusters due to two multiple-antibiotic-resistant strains of genospecies 13 and one strain of A . baumannii, respectively, there was no significant increase of antibiotic resistance discernible during the decade-long period of Acinetobacter surveillance .

Int J Food Microbiol, 2000 Jun 1, 56(2-3), 239 - 44
Bacterial populations associated with bulk packaged beef supplemented with dietary vitamin E; Buys EM et al.; Five Simmentaler type calves were fed diets supplemented with 500 mg vitamin E per day and five fed control diets, Rump steaks from each carcass were PVC-overwrapped and bulk packaged in 100% CO2 or 20% CO2:80% O2 . Bulk packs were stored up to 42 days at 4 degrees C and PVC-overwrapped samples subsequently displayed up to 7 days at 4 degrees C . After display the Aerobic Plate Count (APC) of steaks was determined and four colonies were randomly selected from the highest dilution APC plates showing growth . A total of 627 colonies were obtained . Gram-reaction, catalase, oxidase, morphology and motility of the isolates were determined . The gram-negative and gram-positive isolates were then identified using a dichotomous identification key . Enterobacteriaceae, Pseudomonas spp . and Acinetobacter spp . predominated on rump steaks from both feeding treatments and in packaging treatments . After 42 days bulk storage Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria and Acinetobacter spp . predominated in 20% CO2:80% O2 and 100% CO2 bulk packaging . Enterobacteriaceae, Pseudomonas spp . and Acinetobacter spp . predominated on rump steaks, from both feeding and packaging treatments, during the aerobic display period of 7 days.

Zh Mikrobiol Epidemiol Immunobiol, 1999 Sep-Oct, (5), 77 - 80
{The use of batumin-containing disks for the rapid identification of staphylococci}; Smirnov VV et al.; The study of 467 microbial strains obtained from collections and from clinical sources revealed that microorganisms of the genus Staphylococcus were highly sensitive to batumin, a new antibiotic obtained from bacteria of the genus Pseudomonas . 378 strains of 15 Staphylococcus species proved to be highly sensitive to the diagnostic preparation "Diastaph", developed on the basis of batumin (antibiotic-impregnated discs); After 18-hour incubation the diameter of the growth inhibition zones on agar-containing culture media was 18-38 mm . Strains belonging to the genera Micrococcus, Dermacoccus, Kocuria and Kytococcus, as well as the tested representatives of other taxa (Planococcus, Streptococcus, Corynebacterium, Acinetobacter, Pseudomonas, Neisseria, the representatives of all tested genera of the family Enterobacteriaceae, fungi of the genus Candida) were insensitive to the diagnosticum . "Diastaph" permits not only the rapid identification of staphylococci pure cultures, but also the determination of their presence in association with other microbial species directly in pathological material, which makes it possible to recommend this diagnostic preparation for use in medical, veterinary and sanitary microbiology.

J Bacteriol, 2000 Jul, 182(13), 3673 - 80
ComP, a pilin-like protein essential for natural competence in Acinetobacter sp . Strain BD413: regulation, modification, and cellular localization; Porstendorfer D et al.; We recently identified a pilin-like competence factor, ComP, which is essential for natural transformation of the gram-negative soil bacterium Acinetobacter sp . strain BD413 . Here we demonstrate that transcription and synthesis of the pilin-like competence factor ComP are maximal in the late stationary growth phase, whereas competence is induced immediately after inoculation of a stationary-phase culture into fresh medium . Western blot analyses revealed three forms of ComP, one with an apparent molecular mass of 15 kDa, which correlates with the molecular mass deduced from the DNA sequence, one 20-kDa form, which was found to be glycosylated, and one 23-kDa form . The glycosylation of ComP was not required for its function in DNA binding and uptake . The 20-kDa form was present in the cytoplasmic membrane, the periplasm, and the outer membrane, whereas the 23-kDa form was located in the outer membrane and might be due to a further modification . Immunological data suggest that ComP is not a subunit of the pilus structures . Possible functions of ComP in the DNA transformation machinery of Acinetobacter sp . strain BD413 are discussed.

Eur J Clin Microbiol Infect Dis, 2000 Apr, 19(4), 320 - 3
Bacteraemia caused by non-glucose-fermenting gram-negative bacilli and Aeromonas species in patients with haematological malignancies and solid tumours; Martino R et al.; The clinical characteristics and outcome of bacteraemia caused by non-glucose-fermenting gram-negative bacilli and Aeromonas spp . were examined in 115 adults with haematological malignancies or solid tumours . The most aggressive pathogens were Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Aeromonas spp., Acinetobacter spp . and Burkholderia cepacia, all of which caused either septic syndrome or pneumonia in more than 40% of cases . Pseudomonas aeruginosa was involved less often in catheter-related bacteraemia than other species . Polymicrobial bacteraemia (n=28) was more often catheter-related than monomicrobial bacteraemia and more often required catheter removal for definitive cure . The most important predictors of catheter-related bacteraemia and its outcome were polymicrobial infection, the presence of pneumonia or septic syndrome and the species involved.

Tidsskr Nor Laegeforen, 2000 Mar 30, 120(9), 1028 - 33
{Outbreak of multiresistant Acinetobacter baumannii infection}; Onarheim H et al.; BACKGROUND: Nosocomial infections caused by multiresistant gram-negative bacteria represent an increasing problem, especially among intensive care patients . A serious outbreak of infection caused by multi-resistant Acinetobacter baumannii occurred in four burn patients . Acinetobacter is a gram-negative coccibacilli which is widespread in nature, and has been reported as an increasing problem in critically ill patients . MATERIALS AND METHODS: The outbreak strain was introduced from Alicante, Spain, by a transferred patient . This strain was resistant to all commonly available systemic antibiotics (including the karbapenems and all aminoglycosides), and sensitive only to polymyxin B . Two patients were critically ill, one of them died in septic shock . RESULTS: The ward was closed for admission of new patients and hygiene precautions were strengthened . Extensive testing of staff and equipment revealed multi-resistant A baumannii on a shower trolley shared by several patients . The outbreak strain was also identified by restriction endonuclease analysis . The patients were kept strictly isolated until their burn wounds were sufficiently healed to allow them to be discharged to their homes . INTERPRETATION: Following discharge of the last patient and extensive cleaning and disinfection of the entire ward, the particularly resistant strain has not reoccurred . Still, this experience may warrant screening for multiresistant gram-negative rods in patients transferred from regions where broad resistance to antibiotics is a common problem.

Indian J Pediatr, 2000 Jan, 67(1), 27 - 32
Neonatal gram-negative bacteremia; Joshi SG et al.; A 22 months prospective study of neonatal gram-negative bacteremia was undertaken in a 15 bed NICU to find out the incidence and antibiotic resistance patterns . Clinically suspected 1326 cases of neonatal sepsis were studied during this period . More than 25% of the cases were microbiologically positive for sepsis . Among 230 (67.2%) cases of gram-negative bacteremia, the predominant isolates were Pseudomonas aeruginosa (38.3%), Klebsiella pneumoniae (30.4%), Escherichia coli (15.6%) and Acinetobacter sp . (7.8%) . Fifty-nine per cent of the neonates were born in hospital while 41% were from community and referral cases . Lower respiratory tract infection, umbilical sepsis, central intravenous line infection and infection following invasive procedures were the most commonly identified sources of septicemia . Prematurity and low birth weight were the main underlying conditions in 60% of the neonates . Total mortality was 32% . Increased mortality was mainly associated with neutropenia, nosocomial infection and inappropriate antibiotic therapy . Resistance was increasingly noted against many antibiotics . The isolates were predominantly resistant to extended spectrum cephalosporins (25%-75%), piperacillin (68%-78%), and gentamicin (23%-69%) . The commonest microorganisms causing gram-negative bacteremia were Pseudomonas aeruginosa followed by Klebsiella pneumoniae . The community-acquired bacteremia was mainly due to E . coli . The proportion of preterm and low birth weight babies was significantly high, and the major contributing factor in total mortality . Sensitivity to different antibiotics conclusively proved that a combination of ampicillin + sulbactam with amikacin or ampicillin + sulbactam with ciprofloxacin is most effective.

Appl Environ Microbiol, 2000 Jun, 66(6), 2311 - 7
Bioconversion of ferulic acid into vanillic acid by means of a vanillate-negative mutant of Pseudomonas fluorescens strain BF13; Civolani C et al.; From a ferulic-acid-degrading Pseudomonas fluorescens strain (BF13), we have isolated a transposon mutant, which retained the ability to bioconvert ferulic acid into vanillic acid but lost the ability to further degrade the latter acid . The mutant, BF13-97, was very stable, and therefore it was suitable to be used as a biocatalyst for the preparative synthesis of vanillic acid from ferulic acid . By use of resting cells we determined the effect on the bioconversion rate of several parameters, such as the addition of nutritional factors, the concentration of the biomass, and the carbon source on which the biomass was grown . The optimal yield of vanillic acid was obtained with cells pregrown on M9 medium containing p-coumaric acid (0.1% {wt/vol}) as a sole carbon source and yeast extract (0.001% {wt/vol}) as a source of nutritional factors . Under these conditions, 1 mg (wet weight) of biomass produced 0.23 mg of vanillic acid per h . The genomic region of BF13-97 flanking the transposon's site of insertion was cloned and sequenced revealing two open reading frames of 1,062 (vanA) and 954 (vanB) bp, respectively . The van genes are organized in a cluster and encode the subunits of the vanillate-O-demethylase, which catalyzes the first step of the vanillate catabolism . Amino acid sequences deduced from vanA and vanB genes were shown to have high identity with known VanAs and VanBs from Pseudomonas and Acinetobacter spp . Highly conserved regions known to exist in class IA oxygenases were also found in the vanillate-O-demethylase components from P . fluorescens BF13 . The terminal oxygenase VanA is characterized by a conserved Rieske-type {2Fe-2S}(R) ligand center . The reductase VanB contains a plant-type ferredoxin {2Fe-2S}(Fd), flavin mononucleotide, and NAD-ribose binding domains which are located in its C-terminal and N-terminal halves, respectively . Transfer of wild-type vanAB genes to BF13-97 complemented this mutant, which recovered its ability to grow on either vanillic or ferulic acid.

FEMS Microbiol Lett, 2000 Jun 1, 187(1), 65 - 8
Repression of Acinetobacter vanillate demethylase synthesis by VanR, a member of the GntR family of transcriptional regulators; Morawski B et al.; Vanillate is converted to protocatechuate by the action of vanillate demethylase encoded by vanAB . Convergent upon and overlapping Acinetobacter vanB is an open reading frame encoding a member of the gntR repressor family and designated vanR . This gene organization differs from that found in a Pseudomonas isolate . An Acinetobacter strain with a knockout mutation in vanR constitutively converted vanillate to protocatechuate . Reverse transcriptase-polymerase chain reaction was used to demonstrate that control of vanAB was exerted at the level of transcription.

J Antimicrob Chemother, 2000 Apr, 45 Suppl 1, 71 - 7
Bactericidal and bacteriostatic activity of gemifloxacin against Acinetobacter spp . in vitro; Higgins PG et al.; This study compared the in vitro bacteriostatic activity of gemifloxacin (SB-265805) and a panel of test antimicrobial agents against 100 clinical isolates of Acinetobacter spp . (47 Acinetobacter baumannii, 18 Acinetobacter anitratus, 18 Acinetobacter lwoffii, 13 Acinetobacter calcoaceticus and four other Acinetobacter spp.) . Gemifloxacin (MIC(50/90) 0.06/16 mg/L) was more than eight-fold more potent than ciprofloxacin (0.5/>128 mg/L), two- to eight-fold more potent than grepafloxacin, moxifloxacin, levofloxacin, ofloxacin and gatifloxacin, and of similar potency to trovafloxacin and sparfloxacin . Cross-resistance was seen only within the quinolone group and did not extend to non-quinolone antimicrobials . The bactericidal activities of gemifloxacin and the six comparator quinolones were investigated by dose-response and time-kill studies against A . baumannii ATCC 19606 at their optimum bactericidal concentration (OBC) and at 4 x MIC . At the OBC there was no significant difference between the quinolones, but at 4 x MIC gemifloxacin showed superior activity, reducing the viable count by almost 2 log(10) in 30 min compared with a 1 log(10) reduction seen with the other drugs . This enhanced killing extended over 24 h, reducing cell numbers by >4 log(10) . These data suggest that gemifloxacin has the potential to be of therapeutic value in the treatment of infection by Acinetobacter spp.

J Trauma, 2000 May, 48(5), 964 - 70
Acinetobacter calcoaceticus pneumonia and the formation of pneumatoceles; Hunt JP et al.; Pneumatoceles are cystic lesions of the lungs often seen in children with staphylococcal pneumonia and positive-pressure ventilation . Acinetobacter calcoaceticus is an aerobic, short immobile gram-negative rod, or coccobacillus, which is an omnipresent saprophyte . The variant anitratus is the most clinically significant pathogen in this family, usually presenting as a lower respiratory tract infection . Acinetobacter has been demonstrated to be one of the most common organisms found in the ICU . We present three critically ill surgery patients with Acinetobacter pneumonia, high inspiratory pressures, and the subsequent development of pneumatoceles . One of these patients died from a ruptured pneumatocele, resulting in tension pneumothorax . Treatment of pneumatoceles should center on appropriate intravenous antimicrobial therapy . This should be culture directed but is most often accomplished with Imipenem . Percutaneous, computed tomographic-guided catheter placement or direct tube thoracostomy decompression of the pneumatocele may prevent subsequent rupture and potentially lethal tension pneumothorax.

Biol Pharm Bull, 2000 May, 23(5), 649 - 53
Cloning and characterization of the ddc homolog encoding L-2,4-diaminobutyrate decarboxylase in Enterobacter aerogenes; Yamamoto S et al.; L-2,4-diaminobutyrate decarboxylase (DABA DC) catalyzes the formation of 1,3-diaminopropane (DAP) from DABA . In the present study, the ddc gene encoding DABA DC from Enterobacter aerogenes ATCC 13048 was cloned and characterized . Determination of the nucleotide sequence revealed an open reading frame of 1470 bp encoding a 53659-Da protein of 490 amino acids, whose deduced NH2-terminal sequence was identical to that of purified DABA DC from E . aerogenes . The deduced amino acid sequence was highly similar to those of Acinetobacter baumannii and Haemophilus influenzae DABA DCs encoded by the ddc genes . The lysine-307 of the E . aerogenes DABA DC was identified as the pyridoxal 5'-phosphate binding residue by site-directed mutagenesis . Furthermore, PCR analysis revealed the distribution of E . aerogenes ddc homologs in some other species of Enterobacteriaceae . Such a relatively wide occurrence of the ddc homologs implies biological significance of DABA DC and its product DAP.

Antimicrob Agents Chemother, 2000 Jun, 44(6), 1556 - 61
OXA-24, a novel class D beta-lactamase with carbapenemase activity in an Acinetobacter baumannii clinical strain; Bou G et al.; Acinetobacter baumannii RYC 52763/97, a clinical isolate involved in a prolonged nosocomial outbreak at our hospital, was resistant to all beta-lactams tested, including imipenem and meropenem, which had MICs of 128 and 256 microg/ml, respectively . This strain synthesized three beta-lactamases: a plasmid-mediated TEM-1 beta-lactamase (pI 5.4), an AmpC-type chromosomal cephalosporinase (pI 9.4), and a novel, presumptively chromosomally mediated OXA-related enzyme (pI 9.0) named OXA-24 . After cloning and sequencing, the deduced amino acid sequence of the OXA-24 beta-lactamase showed 40% homology with the OXA-10 (PSE-2) and OXA-7 beta-lactamases, 39% homology with the OXA-11 and OXA-5 enzymes, and 33% homology with the LCR-1 beta-lactamase . The amino acid sequence of the OXA-24 beta-lactamase contained the STFK motif found in serine beta-lactamases, but the typical class D triad KTG was replaced by KSG and the motif YGN was replaced by FGN . The OXA-24 beta-lactamase hydrolyzed benzylpenicillin and cephaloridine but lacked activity against oxacillin, cloxacillin, and methicillin . The enzymatic activity was inhibited by chloride ions and by tazobactam (50% inhibitory concentration {IC(50)}, 0.5 microM), sulbactam (IC(50), 40 microM), and clavulanic acid (IC(50), 50 microM) . Carbapenem MICs for an Escherichia coli transformant (pBMB-1) expressing the cloned OXA-24 enzyme had a fourfold increase . Relative V(max)/K(m) values of 13 and 6 were obtained with imipenem and meropenem, respectively, and a positive microbiological assay result with imipenem was obtained with a purified enzymatic extract of this transformant strain . Therefore, we consider this new beta-lactamase to be involved in the carbapenem resistance of A . baumannii RYC 52763/97.

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