J Hosp Infect, 2000 Jan, 44(1), 13 - 7 Invasive disease due to extended spectrum beta-lactamase-producing Klebsiella pneumoniae in a neonatal unit: the possible role of cockroaches; Cotton MF et al.; We recently experienced an outbreak of nosocomial disease due to extended spectrum beta-lactamase-producing Klebsiella pneumoniae in a neonatal unit infested with cockroaches . Organisms isolated from cockroaches were indistinguishable by pulsed-field gel electrophoresis from those colonizing infants or causing clinical disease using . Cockroach elimination together with standard infection-control measures resulted in control of the outbreak . We suggest cockroaches are possible vectors of pathogenic bacteria in the hospital environment. J Antimicrob Chemother, 2000 Jan, 45(1), 105 - 9 Effect of conalbumin on the activity of Syn 2190, a 1,5 dihydroxy-4-pyridon monobactam inhibitor of AmpC beta-lactamases; Babini GS et al.; Syn 2190, a 1,5 dihydroxy-4-pyridon monobactam inhibitor of AmpC enzymes, was tested against beta-lactamase-producing bacteria with piperacillin, piperacillin-tazobactam and ceftazidime as partner drugs . In the presence of conalbumin as an iron chelator, Syn 2190 potentiated these drugs against most AmpC producers, although Klebsiella spp . with plasmidic AmpC enzymes were an exception . Potentiation was much weaker without conalbumin, suggesting that Syn 2190 exploits a ferric uptake pathway, as do catecholic cephalosporins . Syn 2190 had little ability to potentiate partner drugs against strains with other beta-lactamase types but, with conalbumin, increased the activity of piperacillin-tazobactam against Escherichia coli transconjugants producing various class A or D enzymes. J Antimicrob Chemother, 2000 Jan, 45(1), 69 - 75 Evaluation of trovafloxacin in the treatment of Klebsiella pneumoniae lung infection in tumour-bearing mice; Thadepalli H et al.; Trovafloxacin, a new trifluoroquinolone, was evaluated for its therapeutic efficacy against Klebsiella pneumoniae lung infection in tumour (P388 murine leukaemia cells)-bearing mice, treated with or without a chemotherapeutic agent, daunorubicin (DNR) and in mice without tumour . Its activity was compared with ciprofloxacin and cephazolin . The effect on therapeutic efficacy of the addition of recombinant granulocyte colony stimulating factor (rGCSF) was also examined . Our study showed that both quinolones successfully cured pneumonia owing to infection with K . pneumoniae in mice without tumours but that all antibiotics failed in tumour-bearing mice if DNR was withheld . Substantial differences were noted in DNR-treated tumour-bearing mice with infection-the cure rate with trovafloxacin was 91% whereas the cure rate with ciprofloxacin or cephazolin was 57% . Addition of rGCSF to ciprofloxacin did not substantially improve its efficacy (when assessed by protection against death owing to infection; the survival rate was 41%) . Trovafloxacin cure rates ranged from 80 to 90% whether or not rGCSF was added to the treatment regimen . Our results suggest that prior cancer chemotherapy had no adverse effect on the therapeutic efficacy of trovafloxacin, and that trovafloxacin may be a promising therapeutic agent for treatment of bacterial infections in the presence of leucopenia. QJM, 2000 Jan, 93(1), 45 - 53 Klebsiella pneumoniae meningitis: timing of antimicrobial therapy and prognosis; Fang CT et al.; We analysed the clinical course of 30 adult patients with Klebsiella pneumoniae meningitis, 18 community-acquired and 12 hospital-acquired, to assess whether the timing of appropriate antimicrobial therapy had a major effect on prognosis . Of the 30 patients, 29 received appropriate antibiotics . The time from initial symptoms to the start of appropriate therapy, antibiotic resistance of K . pneumoniae isolates, underlying disease severity, diabetes mellitus, age, gender, and acquisition settings were all not significantly correlated with outcome . However, a Glasgow coma scale (GCS) score of 7 points or less at the start of appropriate antimicrobial therapy was a valid predictor of death or a permanent vegetative state (sensitivity 82%, specificity 93%, p=0.005), even after adjusting for the effect of confounding variables by logistic regression . Timing of appropriate antimicrobial therapy, as defined by consciousness level but not by symptom duration, is a major determinant of survival and neurological outcome for patients with K . pneumoniae meningitis, and the first dose of an appropriate antibiotic should be administrated before their consciousness deteriorates to a GCS score of 7 points or less. Infection, 1999 Nov-Dec, 27(6), 368 - 9 Spontaneous spondylodiscitis caused by Klebsiella pneumoniae; Kouroussis C et al.; A rare case of spontaneous spondylodiscitis caused by Klebsiella pneumoniae in a 55-year-old man who presented with thoracolumbar pain is described . Increased erythrocyte sedimentation rate and C-reactive protein level were pertinent laboratory findings . Computed tomography revealed a paravertebral mass and destruction of the 10th and 11th vertebrae . Magnetic resonance imaging (MRI) showed spondylodiscitis in the same area . Culture of a biopsy sample from the mass grew Klebsiella pneumoniae, while histological examination confirmed the inflammation . A combination of ceftazidime, amikacin and ciprofloxacin resulted in disappearance of the pain . Two months later, MRI showed substantial improvement of the lesions. Infection, 1999 Nov-Dec, 27(6), 348 - 54 Occurrence of extended-spectrum betalactamases (ESBL) in Dutch hospitals; Stobberingh EE et al.; The prevalence of ESBL was determined among isolates of Escherichia coli (n = 571) and Klebsiella spp . (n = 196) collected during a 1-week study period in 8 university and 3 large regional laboratories all over the Netherlands . 18 isolates were positive for at least one of the screening tests used, i.e., VITEK-ESBL, E-test ESBL and MIC ratio of ceftazidime/ceftazidime-clavulanic acid, cefotaxime/cefotaxime-clavulanic acid . In 5 of these 18 putative ESBLs no betalactamase production was detectable . A TEM type was found in three E . coli and two Klebsiella spp . An SHV type was present in five Klebsiella spp . In one E . coli and one Klebsiella pneumoniae both enzymes were present . In one Klebsiella oxytoca neither of the two enzymes was present . Using PCR for both ESBL TEM and ESBL SHV, an SHV ESBL was found in one E . coli and four Klebsiella isolates . The mutations at position 238 and 240 were already described . In one E . coli isolate a TEM ESBL was found with three mutations, at position 21, 164 and 265 . These mutations were already described in other ESBLs but not in this combination suggesting a new TEM ESBL . The overall prevalence of ESBL producing E . coli and Klebsiella spp . was less than 1% (6 out of 767). Clin Infect Dis, 2000 Jan, 30(1), 55 - 60 Outbreak of a multiresistant Klebsiella pneumoniae strain in an intensive care unit: antibiotic use as risk factor for colonization and infection; Asensio A et al.; An observational study was undertaken to describe a nosocomial outbreak caused by multiresistant Klebsiella pneumoniae (MRKP) . Ten patients in the pediatric intensive care unit (ICU) at a hospital in Madrid were colonized by or infected with MRKP from October 1997 to April 1998 . Thirty-two patients with MRKP-negative surveillance cultures who were admitted to the ICU during the outbreak period were selected as control patients . Random amplified polymorphic DNA analysis of MRKP isolates revealed patterns that were indistinguishable from each other . After identification of colonized patients by surveillance cultures and implementation of standard and contact precautions, the outbreak was controlled . An age <12 weeks (odds ratio {OR}, 13.1) and previous treatment with third-generation cephalosporins and aminoglycosides (OR, 31.2) were independently associated with MRKP colonization and/or infection . Individual exposure to antibiotics, irrespective of other clinical determinants, is a risk factor for MRKP acquisition . Screening high-risk patients during outbreaks and reducing the use of third-generation cephalosporins and aminoglycosides contribute to the control of these epidemics. J Clin Microbiol, 2000 Jan, 38(1), 412 - 4 Identification of a major cluster of Klebsiella pneumoniae isolates from patients with liver abscess in Taiwan; Lau YJ et al.; Klebsiella pneumoniae has emerged as the leading liver abscess pathogen in Taiwan, with the percentage rising from 30% in the 1980s to over 80% in the 1990s . Most of the patients with K . pneumoniae liver abscess are diabetic and without biliary tract disease . Some patients develop serious extrahepatic complications such as endophthalmitis, meningitis, lung abscess, and necrotizing fasciitis . Pulsed-field gel electrophoresis (PFGE) was used for cluster analysis of 96 isolates from patients with liver abscess and 60 isolates from patients with other diseases . A total of 136 PFGE types were identified . Among the 96 liver abscess-associated isolates, 60 (62.5%) were classified in major cluster A . Cluster A included 41 PFGE types (types 1 to 41) which had a genetic similarity of at least 72.4% +/- 9.4% . The PFGE patterns of cluster A strains are so similar that they could have originated from the same ancestor . This study demonstrates that cluster A plays an important role in the high incidence of K . pneumoniae liver abscess in Taiwan. Chirurgie, 1999 Nov, 124(5), 529 - 35 {Laparoscopy or laparotomy in acute cholecystitis (200 cases) . Comparison of the results and factors predictive of conversion}; Araujo-Teixeira JP et al.; STUDY AIM: The aim of this prospective study was to compare the results of cholecystectomy for acute cholecystitis through laparoscopic and open approach and to assess factors responsible for conversion into laparotomy . PATIENTS AND METHODS: From January 1991 to October 1997, 200 patients with calculous acute cholecystitis were operated on in the same center, 100 through laparoscopy and 100 through laparotomy . Choice between these two procedures was only dependent on the disresponsibility of videolaparoscopic material . Comparison between laparoscopy and laparotomy groups concerned postoperative mortality and morbidity rates, hospital stay duration and late results . Intraoperative conversion into laparotomy occurred in 24 patients and factors responsible for conversion were assessed with univaried and multivaried analysis . RESULTS: Both groups were comparable with regard to sex ratio, age, ASA score but associated diseases incidence, plastron, fever above 38 degrees C and leucocytosis were significantly more frequent in the laparotomy group and delay between diagnosis and surgery was significantly longer in the laparoscopic group . There were two postoperative deaths in the laparotomy group, 0 in the laparoscopic group (NS) . Morbidity rate was higher (32% versus 10%) (p = 0.0002) and hospital stay longer (12 +/- 10 days, versus 5 +/- 3) in the laparotomy group (p = 0.00005) . Late results were similar in both groups . Conversion rate into laparotomy was 24% . Factors predisposing significantly to conversion were in univaried analysis: plastron, fever above 38 degrees C, leucocytosis, delay between diagnosis and surgery above 4 days, presence on ultrasonography of pericholecystic liquid and gallbladder wall edema, presence of "Klebsiella" in gallbladder bile . With multivaried analysis, leucocytosis and delay between diagnosis and surgery were the only independent factors . CONCLUSION: Videolaparoscopic cholecystectomy is a safe and efficient technique in the treatment of acute cholecystitis, with a lower postoperative morbidity rate and a shorter hospital stay . Conversion rate into laparotomy is significantly dependent on leucocytosis and delay between diagnosis and surgery . Laparoscopic cholecystectomy should be performed as soon as possible in acute cholecystitis. Chemotherapy, 2000 Jan-Feb, 46(1), 1 - 14 Nosocomial outbreak of cross-infection due to multiple-antibiotic-resistant Klebsiella pneumoniae: characterization of the strain and antibiotic susceptibility studies; Traub WH et al.; A multiple-antibiotic-resistant (MAR) strain of Klebsiella pneumoniae was introduced into a pediatric ward and subsequently colonized neonates of two wards with several cases of systemic infection . This strain produced an extended-spectrum beta-lactamase and was resistant to cefotaxime, ceftazidime, and, among others, all aminoglycosides including amikacin . The majority of representative isolates examined with macrorestriction analysis of genomic DNA (pulsed-field gel electrophoresis) were identical . The strain was susceptible to the innate antibacterial systems operative in fresh defibrinated blood from two adults . Combined human blood/antimicrobial drug assays documented the in vitro bactericidal activity of carbapenems (meropenem was slightly more effective than imipenem), fluoroquinolones (ciprofloxacin and trovafloxacin), and polymyxin B against this MAR strain of K . pneumoniae . J Microbiol Immunol Infect, 1998 Jun, 31(2), 90 - 4 Comparison of detection of extended-spectrum beta-lactamases by agar dilution method, E-test ESBL screen and double disk test; Tseng CY et al.; The extended-spectrum beta-lactamases (ESBL) are derived from TEM-or SHV-enzymes . They mediate resistance to broad-spectrum beta-lactams and can cause infectious outbreaks in hospitals . Rapid recognition and diagnosis are important for the clinician to prescribe more effective treatment . In the present study, a group of 52 probable ESBL-producing Klebsiella pneumoniae and Escherichia coli having a suspected resistant antibiogram phenotype were included . The E-test ESBL screen and the double disk test were performed for these isolates for detection of ESBL-producing strains, as compared with the conventional agar dilution method . The agreement between the E-test ESBL screen or the double disk test and the conventional agar dilution method was good and the degree of agreement were 86.5% and 92.3% respectively . The results showed that both the E-test ESBL screen and the double disk test were useful and convenient for detection of ESBLs. J Appl Microbiol, 1999 Nov, 87(5), 764 - 9 The survival and growth of an environmental Klebsiella isolate in detergent solutions; Beadle IR et al.; A Klebsiella isolate (G1) was capable of survival and growth in an environment containing high levels of anionic (15.6%) and non-ionic detergent (7.8%) . Cell numbers were monitored by traditional viable plate counts (culturability), and by staining with Rhodamine 123 (vital counts) and Acridine Orange (total counts) . On inoculation into detergent solutions, only 10% of cells retained vitality (rhodamine 123) after 24 h . Of those, only 1% were able to form colonies on artificial culture media . Under low nutrient conditions (TOC < 0.89 mg l - 1), no recovery was observed over a 96 h period, but addition of nutrients (TOC 3.84 mg l - 1) allowed recovery within 48 h . Such cells were initially (24 h) elongated, but subsequently (144 h) returned to their normal size . In the presence of detergent without added nutrient, cell size was reduced after 144 h . After adaptation to the detergent environment (24 - 48 h), cell numbers in detergent with added nutrient broth (vital, viable and total) rose, until levels equivalent to those of a detergent-free control were attained . Detergent solutions provide a stressful environment . Nutrient levels in the detergent solutions affected cell size and the ability of the Klebsiella (G1) to survive and grow. Neurol Neurochir Pol, 1999 May-Jun, 33(3), 693 - 8 {Successful treatment with bacteriophage in purulent cerebrospinal meningitis in a newborn}; Stroj L et al.; The subject of this report is the case of purulent meningitis in new-born caused by Klebsiella pneumoniae . As the intensive antibiotic therapy turned out to be ineffective phage therapy was applied . Oral administration of specific phage preparate for the period of 5 weeks resulted in complete sterilization of cerebrospinal fluid and unquestionable improvement of child's health . However, after several ventriculopunctures some complications appeared (haemorrhage into central nervous system, extra infection) . They were treated in standard way . Because of increasing internal hydrocephalus and necessity of operation, the child was sent to suitable hospital for further treatment. J Trop Pediatr, 1999 Oct, 45(5), 271 - 7 Molecular typing of multiresistant Klebsiella pneumoniae isolated from children from northern Jordan; Youssef MT et al.; Twenty-nine clinical isolates of community acquired Klebsiella pneumoniae obtained from 17 children with malnutrition were characterized by antibiotic susceptibility, plasmid analysis, and random amplified polymorphic DNA (RAPD) techniques . Disc diffusion methodology was used to test the susceptibility of the isolates to 13 antibiotics: amoxycillin, cephapirin, ceftazidime, cefoxitin, cefotaxime, aztreonam, gentamicin, ciprofloxacin, chloramphenicol, erythromycin, nalidixic acid, trimethoprim and amoxycillin-clavulanic acid . All the isolates showed multiresistance patterns (15 patterns) ranging from resistance to two antibiotics to resistance to 10 antibiotics . All isolates were resistant to amoxycillin and erythromycin . Ten K . pneumoniae isolates producing extended-spectrum beta-lactamases (ESBLs) as evidenced by the double-disc diffusion synergy test were isolated sporadically from six patients . Six of these 10 isolates were hyperproducers of ESBL, which resulted in increased resistance to the beta-lactam-beta-lactamase inhibitor combination amoxycillin-clavulanic acid . Plasmid analysis showed plasmid ranging in size from 48 kilobases (kb) to 1.4 kb . All the 29 isolates shared the same plasmid 26 kb . There was a consistent relationship between antibiotype and plasmid profiles for each pair of isolates obtained from five individual patients . RAPD analysis using a single (10-mer) primer demonstrated that the isolates that have the same antibiotype and the same plasmid profile had different RAPD fingerprint patterns . These results demonstrate that the RAPD technique is better than antibiotype characterization and a plasmid analysis profile for typing K . pneumoniae as well as for revealing strain differences. Ugeskr Laeger, 1999 Oct 18, 161(42), 5814 - 7 {Antimicrobial effects of anesthetics and analgesics}; Bender AB et al.; Drugs, not designed as antibiotics, and whose primary mode of action is modulation of active and passive ionic transport-mechanisms in the eucaryotic cell, also act on procaryotic cell-walls, and the action is antimicrobial . The drugs may be classified, non-antibiotics . Anaesthetic gases are bactericidal in the fluid state, and in the vaporous state at high concentrations . Local anaesthetics of the ester type have stronger antimicrobial actions than the amidetype, and synergy is found between local anaesthetics and antibiotics . Barbiturates show antimicrobial action at high concentrations, and there is a possible synergy with antibiotics . Synthetic analogs of morphine have stronger antimicrobial action than the natural derivatives . Aspirin (ASA) inhibits the growth of Klebsiella pneumoniae at concentrations within the range of that in plasma in normal clinical usage; but induces non-genetical resistance to antibiotics . Increasing problems of bacterial resistance to common antibiotics might render non-antibiotics subject to development into antibiotics, and to be utilized in combination treatment of resistant infectious diseases. Rev Pneumol Clin, 1999 Sep, 55(4), 219 - 22 {Mediastinitis caused by Klebsiella pneumoniae with a pharyngeal portal}; Abid A et al.; We report a case of Klebsiella pneumoniae medisatinitis secondary to a retrophyarygeal abscess in a 40-year-old patient . The patient was treated with antibiotics and pleural drainage . Surgery was not necessary and the clinical course was favorable . We recall the pathophysiological and clinical aspects of this now uncommon condition and discuss the prognosis and therapeutic options. Pediatr Infect Dis J, 1999 Nov, 18(11), 963 - 7 Klebsiella pneumoniae with extended spectrum beta-lactamase activity associated with a necrotizing enterocolitis outbreak; Gregersen N et al.; BACKGROUND: Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in newborn infants, affecting primarily premature neonates . Clustering of cases in epidemics is well-described; many are associated with an identifiable pathogen . PATIENTS AND METHODS: Case reports are presented of six neonates seen with NEC during a 2-month period in 1998 . All bacterial isolates were subjected to antibiotic testing, determination of MIC and molecular fingerprinting . RESULTS: Klebsiella pneumoniae with extended spectrum beta-lactamase production was isolated from blood cultures of all six patients . In five patients the isolate appeared to be a single clone . The onset of NEC in the patients was earlier, more rapid and more severe than usual . Four of the six required surgery and five required mechanical ventilation . Two of the six patients died, but only one was directly related to a complication of NEC . All of the patients developed severe thrombocytopenia (platelet count <20 x 10(9)/l), and three developed hepatitis . The K . pneumoniae proved difficult to eradicate . Extended courses of multiple antibiotics were administered and measures were introduced to reduce overcrowding and improve infection control . CONCLUSION: The isolation of a single clone of K . pneumoniae with extended spectrum of beta-lactamase activity during an NEC outbreak highlights the need for strict infection control . This organism caused significant morbidity and was difficult to treat. Rhinology, 1999 Sep, 37(3), 125 - 30 Characteristics of atrophic rhinitis in Thai patients at the Siriraj Hospital; Bunnag C et al.; The common characteristics of primary atrophic rhinitis were studied in 46 Thai patients . From history and demographic data the female to male ratio was found to be 5.6 to 1 . The significance of environmental factors was supported by the findings that 69.6% were people from rural areas and 43.5% were industrial workers but a hereditary factor has not been confirmed . The results of the blood tests did not elucidate iron deficiency anemia or nutritional deficiency as the cause of primary atrophic rhinitis . However, all nasal swab cultures yielded pathogenic organisms where Klebsiella species especially, K . ozaena, were the most common bacteria isolated which were 100% susceptible to cephalosporins . This finding together with the evidence of sinusitis seen in 58.7% of either plain x-rays or CT scans, was suggestive of the important role of infection in atrophic rhinitis . Atrophic change of the mucosa and bone with widening of the nasal cavity were constant findings in the CT scans but the developmental anomaly of the maxillary antrum was found in only 15.2% . The histological study showed characteristic changes especially squamous metaplasia and 80% of the cases were compatible with the Type II histopathological classification, i.e . vasodilatation of the capillaries . The mucociliary function was proven to be impaired in accordance with the loss of cilia . The evidence of Type I allergy demonstrated by skin testing, which was obvious in 85%, is highly suggestive of allergic/immunologic disorders . Although many factors have been cited previously as the possible cause of primary atrophic rhinitis, the common characteristics found in our patients indicate that only bacterial infection, environmental factors and allergic/immunologic disorders could be one or more of its multifactorial etiology and should be further investigated. J Clin Microbiol, 1999 Dec, 37(12), 4020 - 7 Bacteremia due to extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae in a pediatric oncology ward: clinical features and identification of different plasmids carrying both SHV-5 and TEM-1 genes; Siu LK et al.; Thirteen patients who had 16 episodes of bacteremia were observed between 1993 and 1997 in a pediatric oncology ward with a high background isolation rate of cefotaxime- or aztreonam-resistant gram-negative bacteria . Four blood isolates were Escherichia coli and 12 were Klebsiella pneumoniae, and these isolates harbored extended-spectrum beta-lactamases (ESBLs) . All episodes of bacteremia were nosocomial, all except one of the episodes occurred in neutropenic patients, and all patients were treated with piperacillin or ceftazidime with amikacin and cefazolin prior to the onset of bacteremia . Nine of 13 patients were receiving extended-spectrum beta-lactam treatment when the bacteremias caused by ESBL producers occurred . Molecular studies revealed that four K . pneumoniae SHV-2-producing isolates from 1994 were of the same clone . Other ESBL producers, including six that carried both TEM-1 and SHV-5, five that carried SHV-5, and one that carried SHV-2 alone, were unrelated . In conclusion, SHV-5 was present in 11 of the 16 isolates and coexisted with TEM-1 in 6 isolates . Acquisition of resistance genes probably occurred under antibiotic selection pressure . This study highlights the importance of routine checks for and detection of ESBL producers . Effective therapy against ESBL producers should be considered early for children who have malignancies and neutropenia and who are septic, despite treatment with a regimen that includes an extended-spectrum beta-lactam, in a clinical setting of an increased incidence of ESBL-producing bacteria. J Biomed Mater Res, 1999, 48(6), 869 - 74 Interactions between the bioactive glass S53P4 and the atrophic rhinitis-associated microorganism klebsiella ozaenae; Stoor P et al.; In an aqueous environment, ions are released from a bioactive glass (BAG) and the pH rises in its vicinity . This may influence both growth and colonization of microorganisms . We studied the effects of the BAG S53P4 on the atrophic rhinitis-associated microorganism Klebsiella ozaenae . The glass was used in the form of granules or discs . Growth inhibition was studied using an agar plate test . Adhesion was studied by incubating bacterial suspension with the glass . The effect of the presence of the bacteria on the formation of the Si-rich layer on the bioactive glass was also analyzed . Furthermore, a follow up study of 19-74 months with ozena patients surgically treated with the BAG S53P4 was performed . The bioactive glass showed no clear growth inhibition of K . ozaenae in the agar plate test . K . ozaenae showed low adherence to the BAG S53P4 . No growth of the microbe was seen on the glass during the 8 h incubations and the Si-rich layer was formed normally . The clinical follow-up study showed no infections of the implants and the symptoms of the patients were markedly reduced . Thus, the BAG S53P4 did not favor adhesion and colonization of K . ozaenae, in vitro, which is supported by the in vivo findings showing no BAG-associated infections or reinfections . FEMS Microbiol Lett, 1999 Nov 15, 180(2), 263 - 70 Studies on the roles of GlnK and GlnB in regulating Klebsiella pneumoniae NifL-dependent nitrogen control; Arcondeguy T et al.; In Klebsiella pneumoniae, nitrogen fixation (nif) genes are regulated in response to fixed nitrogen and oxygen . The activity of the nif-specific transcriptional activator NifA is modulated by NifL, which mediates both oxygen and nitrogen control . The signal transduction protein GlnK is required to relieve the inhibitory effect of NifL on NifA that occurs when the intracellular N status is high and in a wild-type cell, the action of GlnK cannot be substituted by the structurally related protein PII . We have studied the modulation of NifA activity by NifL in an heterologous system in which the host organism is Escherichia coli . Using a DeltaglnB, DeltaglnK mutant, we have shown that the modulation of NifA activity by NifL is dependent on the concentration of GlnK in the cell and that when overproduced, PII can substitute for GlnK . Furthermore, our data suggest that PII can counteract the positive action of GlnK in relieving NifL-dependent inhibition of NifA activity . This negative effect of PII may be physiologically important in establishing repression of nif gene expression when the intracellular nitrogen status rises. FEMS Microbiol Lett, 1999 Nov 15, 180(2), 157 - 61 In-trans regulation of the N-truncated-NIFA protein of Herbaspirillum seropedicae by the N-terminal domain; Monteiro RA et al.; The NifA protein is responsible for transcription activation of nif genes in the endophytic diazotroph Herbaspirillum seropedicae . When expressed in Escherichia coli this NifA protein is unable to activate the transcription of a Klebsiella pneumoniae nifH::lacZ fusion . However, a form of NifA lacking the N-terminal domain did activate transcription and its activity was not inhibited by ammonium . In this work we show that when expressed separately, the N-terminal domain of H . seropedicae NifA protein can restore ammonium control of the N-truncated NifA activity in E . coli . This effect is dependent on the relative concentrations of the N-terminal domain and the N-truncated protein and suggests that the N-terminal domain behaves in this respect in a manner similar to that of NifL of the gamma proteobacteria. J Biol Inorg Chem, 1999 Aug, 4(4), 468 - 77 Characterization of metal-substituted Klebsiella aerogenes urease; Yamaguchi K et al.; Urease possesses a dinuclear Ni active site with the protein providing a bridging carbamylated lysine residue as well as an aspartyl and four histidyl ligands . The apoprotein can be activated in vitro by incubation with bicarbonate/CO2 and Ni(II); however, only approximately 15% forms active enzyme (Ni-CO2-ureaseA), with the remainder forming inactive carbamylated Ni-containing protein (Ni-CO2-ureaseB) . In the absence of CO2, apoprotein plus Ni(II) forms a distinct inactive Ni-containing species (Ni-urease) . The studies described here were carried out to better define the metal-binding sites for the inactive Ni-urease and Ni-CO2-ureaseB species, and to examine the properties of various forms of Co-, Mn-, and Cu-substituted ureases . Xray absorption spectroscopy (XAS) indicated that the two Ni atoms present in the Ni-urease metallocenter are coordinated by an average of two histidines and 3-4 N/O ligands, consistent with binding to the usual enzyme ligands with the lysine carbamate replaced by solvent . Neither XAS nor electronic spectroscopy provided evidence for thiolate ligation in the inactive Ni-containing species . By contrast, comparative studies of Co-CO2-urease and its C319A variant by electronic spectroscopy were consistent with a portion of the two Co being coordinated by Cys319 . Whereas the inactive Co-CO2-urease possesses a single histidyl ligand per metal, the species formed using C319A apoprotein more nearly resembles the native metallocenter and exhibits low levels of activity . Activity is also associated with one of two species of Mn-CO2-urease . A crystal structure of the inactive Mn-CO2-urease species shows a metallocenter very similar in structure to that of native urease, but with a disordering of the Asp360 ligand and movement in the Mn-coordinated solvent molecules . Cu(II) was bound to many sites on the protein in addition to the usual metallocenter, but most of the adventitious metal was removed by treatment with EDTA . Cu-treated urease was irreversibly inactivated, even in the C319A variant, and was not further characterized . Metal speciation between Ni, Co, and Mn most affected the higher of two pKa values for urease activity, consistent with this pKa being associated with the metal-bound hydrolytic water molecule . Our results highlight the importance of precisely positioned protein ligands and solvent structure for urease activity. Int J Syst Bacteriol, 1999 Oct, 49 Pt 4, 1695 - 700 Phylogenetic evidence for reclassification of Calymmatobacterium granulomatis as Klebsiella granulomatis comb . nov; Carter JS et al.; By sequencing a total of 2089 bp of the 16S rRNA and phoE genes it was demonstrated that Calymmatobacterium granulomatis (the causative organism of donovanosis) shows a high level of identity with Klebsiella species pathogenic to humans (Klebsiella pneumoniae, Klebsiella rhinoscleromatis) . It is proposed that C . granulomatis should be reclassified as Klebsiella granulomatis comb . nov . An emended description of the genus Klebsiella is given. Biotechnol Bioeng, 1999 Dec 20, 65(6), 673 - 6 Fermentation of starch by Klebsiella oxytoca p2, containing plasmids with alpha-amylase and pullulanase genes; dos Santos VL et al.; Klebsiella oxytoca P2(pC46), an ethanol-producing recombinant, has been evaluated in fermentation of maltose and starch . The maximum ethanol produced by P2(pC46) was 0.34 g ethanol/g maltose and 0.38, 0.40, or 0.36 g ethanol/g starch in fermentation of 1, 2, or 4% starch, representing 68, 71, and 64% the theoretical yield . The pC46 plasmid transformed to cells of K . oxytoca P2 reduced the ethanol production from maltose and starch . In fermentation of starch after its digestion at 60 degrees C for 24 h, in two-step fermentation, the time for maximum ethanol production was reduced to 12-24 h and the theoretical yield was around 90% . The increase in starch concentration resulted in lower alpha-amylase activity but in higher pullulanase activity . The high activity and thermostability of the amylolytic enzymes from this transformant suggest that it has a potential for amylolytic enzymes source . Clin Diagn Lab Immunol, 1999 Nov, 6(6), 966 - 9 Antigenic homology of the inducible ferric citrate receptor (FecA) of coliform bacteria isolated from herds with naturally occurring bovine intramammary infections; Lin J et al.; Expression of ferric citrate receptor FecA by Escherichia coli and Klebsiella pneumoniae isolated from bovine mastitis was investigated . Transformant E . coli UT5600/pSV66, which produces large quantities of FecA in the presence of citrate, was constructed . The FecA of E . coli UT5600/pSV66 was purified by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and used to prepare polyclonal antiserum in rabbits . All coliform isolates of E . coli (n = 18) and K . pneumoniae (n = 17) from naturally occurring bovine intramammary infections in five herds induced iron-regulated outer membrane proteins when grown in Trypticase soy broth containing 200 microM alpha-alpha'-dipyridyl and 1 mM citrate . Polyclonal antiserum against FecA was used in conjunction with an immunoblot technique to determine the degree of antigenic homology of FecA among isolates . In the presence of citrate, each isolate expressed FecA that reacted with the anti-FecA polyclonal antiserum . The molecular mass of FecA ( approximately 80.5 kDa) was also highly conserved among isolates . Therefore, the ferric citrate iron transport may be induced in coliform bacteria and utilized to acquire iron in milk for survival and growth . The FecA is an attractive vaccine component for controlling coliform mastitis during the lactation period. J Indian Med Assoc, 1999 Jan, 97(1), 3 - 5 Clinical and bacteriological profile of neonatal infections in metropolitan city based medical college nursery; Das PK et al.; Out of 6319 live born babies, 310 (4.9%) with high risk factors and with clinical suspicion of sepsis were studied for incidence pattern of neonatal infections . Incidence of neonatal infection was 2.56% in normal weight babies and 8.42% in low birth weight babies . Total culture positivity was 48.38% . Klebsiella was the most frequent offender, followed by Staph aureus and Staph epidermidis . Majority of klebsiella species were sensitive to ceftriaxone (86%), amikacin (84%) and ceftazidime (80%) . Ceftriaxone was effective against Staph aureus (95%) and Staph epidermidis (95%) . Overall fatality was 17.1%, distinctly higher in low birth weight group (22.06%) than normal weight group (6.18%). Arch Biochem Biophys, 1999 Nov 15, 371(2), 234 - 40 The C-terminal 12 amino acids of sigma(N) are required for structure and function; Studholme DJ et al.; The sigma(N) protein is an alternative sigma subunit of bacterial RNA polymerase . We investigated the role of a 12-amino-acid "tail" at the C-terminus of Klebsiella pneumoniae sigma(N), which was predicted to be largely surface-exposed and to be mostly loop (that is not alpha-helical or beta-strand) . Deletion of this tail from N-terminal hexahistidine-tagged sigma(N) led to loss of sigma(N)-dependent transcription activity in vivo . We overexpressed and purified this deletion-mutant protein for in vitro characterization . The purified deleted protein showed decreased RNA polymerase core- and DNA-binding activities compared to the full-length protein and transcription activity was greatly impaired . Furthermore, evidence from circular dichroism and protease digestion experiments together suggested that deletion of the C-terminus tail resulted in a loss of conformational constraint in the protein . We discuss a possible structural role for the 12 amino acids at the C-terminus of sigma(N) . Antimicrob Agents Chemother, 1999 Nov, 43(11), 2697 - 701 Decreased antipyrine clearance following endotoxin administration: in vivo evidence of the role of nitric oxide; Kitaichi K et al.; Klebsiella pneumoniae endotoxin has been found to decrease hepatic P450-mediated drug-metabolizing enzyme activity in a time-dependent manner . In this study, we investigated the role of nitric oxide (NO) in the decrease in hepatic drug-metabolizing enzyme activity caused by endotoxin in vivo . We measured in vivo pharmacokinetic parameters of antipyrine in rats treated with endotoxin and/or a selective inhibitor of inducible NO synthase (iNOS), S-methylisothiourea . Intraperitoneal injection of endotoxin (1 mg/kg of body weight) dramatically decreased the systemic clearance of antipyrine, reflecting reduced hepatic drug-metabolizing enzyme activity, and significantly increased the level of nitrite and nitrate (NOx) in the plasma . S-Methylisothiourea (10 mg/kg) reversed this decreasing antipyrine clearance and reduced the level of NOx in plasma . Repeated injections of an NO donor, (+/-)-(E)-4-ethyl-2-{(E)-hydroxyimino}-5-nitro-3-hexenamide (FK-409; 10 mg/kg), at a dose which maintained plasma NOx at the same levels as those caused by endotoxin injection, also decreased the systemic clearance of antipyrine . These findings suggest that the overproduction of NO observed in this animal model is at least partially responsible for the significant reduction in the hepatic drug-metabolizing enzyme activity that may happen in a gram-negative bacterial infection. Kansenshogaku Zasshi, 1999 Sep, 73(9), 935 - 8 {A case of endophthalmitis and abscesses in the liver and the lung caused by Klebsiella pneumoniae}; Naito T et al.; {Case report} A 65-year-old male war admitted to a local hospital because of fever . He was treated with piperacillin and clindamycin without noticeable effect . He began to complain of loss of vision on the third hospital day and culture of the blood specimen yielded Klebsiella pneumoniae . He was diagnosed as endophthalmitis and referred to our hospital for further examination . The hematological laboratory test showed leukocytosis (12,700/microliter) and increased CRP (20.4 mg/dl) . A computed tomographic (CT) scan of the thorax revealed multiple lung abscesses . An abdominal ultrasonographic scan and a CT scan of the abdomen revealed multiple liver abscesses . We drained the abscess in the liver and Klebsiella pneumoniae was detected from the sample of aspirated fluid and his sputum . Meropenem was administered intravenously . Fever started to improve on the tenth hospital day and the size of both liver and lung abscesses were reduced . He has lost vision of his right eye . He was discharged after sixty days . He did not have any immunosuppressive underlying disease including HIV infection and diabetes mellitus which cause these lesions. Infect Immun, 1999 Nov, 67(11), 6152 - 6 Klebsiella pneumoniae capsule expression is necessary for colonization of large intestines of streptomycin-treated mice; Favre-Bonte S et al.; The role of the Klebsiella pneumoniae capsular polysaccharide (K antigen) during colonization of the mouse large intestine was assessed with wild-type K . pneumoniae LM21 and its isogenic capsule-defective mutant . When bacterial strains were fed alone to mice, the capsulated bacteria persisted in the intestinal tract at levels of 10(8) CFU/g of feces while the capsule-defective strain colonized at low levels, 10(4) CFU/g of feces . In mixed-infection experiments, the mutant was rapidly outcompeted by the wild type . In situ hybridization on colonic sections revealed that bacterial cells of both strains were evenly distributed in the mucus layer at day 1 after infection, while at day 20 the wild type remained dispersed and the capsule-defective strain was seen in clusters in the mucus layer . These results suggest that capsular polysaccharide plays an important role in the gut colonization ability of K . pneumoniae. J Mol Biol, 1999 Oct 1, 292(4), 871 - 91 New insights into structure-function relationships in nitrogenase: A 1.6 A resolution X-ray crystallographic study of Klebsiella pneumoniae MoFe-protein; Mayer SM et al.; The X-ray crystal structure of Klebsiella pneumoniae nitrogenase component 1 (Kp1) has been determined and refined to a resolution of 1.6 A, the highest resolution reported for any nitrogenase structure . Models derived from three 1.6 A resolution X-ray data sets are described; two represent distinct oxidation states, whilst the third appears to be a mixture of both oxidized and reduced states (or perhaps an intermediate state) . The structures of the protein and the iron-molybdenum cofactor (FeMoco) appear to be largely unaffected by the redox status, although the movement of Ser beta90 and a surface helix in the beta subunit may be of functional significance . By contrast, the 8Fe-7S P-cluster undergoes discrete conformational changes involving the movement of two iron atoms . Comparisons with known component 1 structures reveal subtle differences in the FeMoco environment, which could account for the lower midpoint potential of this cluster in Kp1 . Furthermore, a non-proline- cis peptide bond has been identified in the alpha subunit that may have a functional role . It is within 10 A of the FeMoco and may have been overlooked in other component 1 models . Finally, metal-metal and metal-sulphur distances within the metal clusters agree well with values derived from EXAFS studies, although they are generally longer than the values reported for the closely related protein from Azotobacter vinelandii . A number of bonds between the clusters and their ligands are distinctly longer than the EXAFS values, in particular, those involving the molybdenum atom of the FeMoco. Microbiol Immunol, 1999, 43(8), 795 - 801 Production of murine collagen-induced arthritis using Klebsiella pneumoniae O3 lipopolysaccharide as a potent immunological adjuvant; Takahashi K et al.; Collagen-induced arthritis (CIA) was produced in mice with non H-2q and H-2r haplotypes by repeated immunization of porcine type-II collagen (CII) together with Klebsiella O3 lipopolysaccharide (KO3 LPS) as an immunological adjuvant . Histological changes that appeared in joints of repeatedly immunized mice were characterized by destruction of normal joint structure, synovial hyperplasia with proliferation of synovial cells, and infiltration of inflammatory cells . No such lesions were produced in mice receiving repeated injections of CII alone or KO3 LPS alone . Development of the humoral antibody and the delayed-type hypersensitivity to CII was exclusively found in mice immunized with the mixture of CII and KO3 LPS . It was therefore suggested that arthritis lesions induced by repeated immunization with the mixture of CII and KO3 LPS might be caused by an autoimmune mechanism, and that the experimental model might be useful for characterization of human rheumatoid arthritis (RA). Rocz Panstw Zakl Hig, 1999, 50(2), 219 - 24 {Sensitivity of Klebsiella pneumoniae strains to the disinfectants}; Janowska J; The sensitivity of 2 Klebsiella strains (isolated from hospital environment--Ks and museum--K28) to 7 disinfectants with the sensitivity of referent strain E . coli NCTC 8196 were compared . Suspension method was applied . Determined the sensitivity Klebsiella strains for phenol, septyl, lizol, chloramine, formalin, glutaraldehyde and laurosept in compare with sensitivity of E . coli during 10 minutes of exposure . Certify the insignificant of difference in testing sensitivity of both Klebsiella strains on the majority disinfectants and more sensitive those strains than referent strain E . coli . In the case of chloramine the difference was almost two fold--the value concentration ratio of the solutions giving bactericidal effect for E . coli in comparing the some concentration for Ks was 2.3 . Only in the case of formalin the sensitivity of E . coli and Klebsiella pneumoniae was inverse--the value of concentration ratio was 0.51--E . coli strain was 1.9 more sensitive than Ks strain and 1.6 more sensitive than K28 strain. Rev Clin Esp, 1999 Aug, 199(8), 517 - 9 {Liver abscess caused by Klebsiella pneumoniae in diabetic patients}; Cobo Martinez F et al.; Pyogenic liver abscess are macroscopic collections of pus within the hepatic parenchyma after a bacterial infection . These infections are usually polymicrobial in nature, and in most occasions due to biliary tract diseases or cryptogenetic in origin . Monomicrobial hepatic abscess caused by Klebsiella pneumoniae are uncommon lesions in western countries . These lesions are associated with underlying diseases, particularly diabetes mellitus, and are frequently complicated with septic metastasis . We report here three cases of monomicrobial liver abscess caused by Klebsiella pneumoniae in diabetic patients, without septic metastasis and a favourable outcome. Biochemistry, 1999 Oct 12, 38(41), 13461 - 72 Membrane topology of the beta-subunit of the oxaloacetate decarboxylase Na+ pump from Klebsiella pneumoniae; Jockel P et al.; The topology of the beta-subunit of the oxaloacetate Na+ pump (OadB) was probed with the alkaline phosphatase (PhoA) and beta-galactosidase (lacZ) fusion technique . Additional evidence for the topology was derived from amino acid alignments and comparative hydropathy profiles of OadB with related proteins . Consistent results were obtained for the three N-terminal and the six C-terminal membrane-spanning alpha-helices . However, the two additional helices that were predicted by hydropathy analyses between the N-terminal and C-terminal blocks did not conform with the fusion results . The analyses were therefore extended by probing the sideness of various engineered cysteine residues with the membrane-impermeant reagent 4-acetamido-4'-maleimidylstilbene-2, 2'-disulfonate . The results were in accord with those of the fusion analyses, suggesting that the protein folds within the membrane by a block of three N-terminal transmembrane segments and another one with six C-terminal transmembrane segments . The mainly hydrophobic connecting segment is predicted not to traverse the membrane fully, but to insert in an undefined manner from the periplasmic face . According to our model, the N-terminus is at the cytoplasmic face and the C-terminus is at the periplasmic face of the membrane. Biochim Biophys Acta, 1999 Oct 15, 1421(2), 329 - 39 Localization of sterically stabilized liposomes in Klebsiella pneumoniae-infected rat lung tissue: influence of liposome characteristics; Schiffelers RM et al.; Sterically stabilized liposomes are able to localize at sites of infection and could serve as carriers of antimicrobial agents . For a rational optimization of liposome localization, the blood clearance kinetics and biodistribution of liposomes differing in poly(ethylene glycol) (PEG) density, particle size, bilayer fluidity or surface charge were studied in a rat model of a unilateral pneumonia caused by Klebsiella pneumoniae . It is shown that all liposome preparations studied localize preferentially in the infected lung compared to the contralateral non-infected lung . A reduction of the PEG density or rise in particle size resulted in a higher uptake by the mononuclear phagocyte system, lower blood circulation time and lower infected lung localization . Differences in bilayer fluidity did not affect blood clearance kinetics or localization in the infected lung . Increasing the amount of negatively charged phospholipids in the liposome bilayer did not affect blood clearance kinetics, but did reduce localization of this liposome preparation at the site of lung infection . In conclusion, the degree of localization at the infected site is remarkably independent of the physicochemical characteristics of the PEG liposomes . Substantial selective liposome localization can be achieved provided that certain criteria regarding PEG density, size and inclusion of charged phospholipids are met . These properties seem to be a direct consequence of the presence of the polymer coating operating as a repulsive steric barrier opposing interactions with biological components. Nucleic Acids Res, 1999 Nov 1, 27(21), 4228 - 34 Structural organization and regulation of the plasmid-borne type II restriction-modification system Kpn2I from Klebsiella pneumoniae RFL2; Lubys A et al.; Kpn 2I enzymes of a type II restriction-modification (R-M) system from the bacterium Klebsiella pneumoniae strain RFL2 recognize the sequence 5'-TCCGGA-3' . The Kpn 2I R-M genes have been cloned and expressed in Escherichia coli . DNA sequence analysis revealed the presence of two convergently transcribed open reading frames (ORFs) coding for a restriction endonuclease (Enase) of 301 amino acids (34 . 8 kDa) and methyltransferase (Mtase) of 375 amino acids (42.1 kDa) . The 3'-terminal ends of these genes ( kpn2IR and kpn2IM, respectively) overlap by 11 bp . In addition, a small ORF (gene kpn2IC ) capable of coding for a protein of 96 amino acids in length (10.6 kDa) was found upstream of kpn2IM . The direction of kpn2IC transcription is opposite to that of kpn2IM . The predicted amino acid sequence of this ORF includes a probable helix-turn-helix motif . We show that the product of kpn2IC represses expression of the Kpn 2I Mtase but has no influence on expression of the Enase gene . Such a mode of regulation is unique among R-M systems analyzed so far . The Kpn 2I R-M is located on the K.pneumoniae RFL2 plasmid pKp4.3, which is able to replicate in E.coli cells. Alcohol Clin Exp Res, 1999 Sep, 23(9), 1435 - 45 Effects of ethanol on neutrophil recruitment and lung host defense in nitric oxide synthase I and nitric oxide synthase II knockout mice; Greenberg SS et al.; BACKGROUND: Ethanol (ETOH) inhibits Escherichia coli endotoxin {lipopolysaccharide (LPS)}-mediated induction of nitric oxide (NO) synthase (NOS) transcription and translation in macrophages and neutrophils {polymorphonuclear (PMN) cells} within the lung . ETOH also inhibits PMN recruitment into the lung and enhances NOS I-mediated production of NO . The contribution of the individual NOS isozymes to ETOH-mediated suppression of the host defense response to lung infection has not been defined . METHODS: We evaluated the role of constitutive NOS I and NOS II in ETOH-mediated inhibition of PMN recruitment into the lung and ETOH-mediated suppression of lung clearance of inhaled Klebsiella pneumonia (K . pneumoniae) in female, homozygous transgenic mice deficient in the genes for NOS I (nNOS-KO) or NOS II (iNOS-KO) and their wild-type controls (WT) . RESULTS: Four hours after intratracheal administration of LPS or aerosol inhalation of K . pneumoniae, the lung content of PMNs obtained by bronchoalveolar lavage from WT mice was significantly reduced when compared with that obtained from the lungs of nNOS-KO and iNOS-KO mice . Pretreatment of WT mice with the NOS II inhibitor L-N6-iminoethyllysine (L-NIL; 10 mg/kg, i.p.) or with the NOS I inhibitor 7-nitroindazole (7-NI) (10, 25, or 40 mg/kg, i.p.) 30 min before LPS administration enhanced the lung content of PMNs recoverable by bronchoalveolar lavage . However, pretreatment of iNOS-KO with L-NIL did not affect lung recruitment of PMNs . Moreover, administration of 25 or 40 mg/kg, i.p . of 7-NI to nNOS-KO mice resulted in death of all the animals within 10 min . Pretreatment of nNOS-KO with 7-NI (10 mg/kg) did not affect LPS-stimulated PMN recruitment . Pretreatment of mice with ETOH (4.5 g/kg, i.p.) produced a greater inhibition of LPS-stimulated lung recruitment of PMNs in iNOS-KO mice than in WT mice . In contrast, pretreatment of nNOS-KO with ETOH produced little inhibition of LPS-stimulated lung recruitment of PMNs when compared with that measured in WT mice . Finally, 4 hr after aerosol inhalation of K . pneumoniae, lung clearance of this bacteria was enhanced in iNOS-KO when compared with WT and inhibited in nNOS-KO when compared with WT mice . ETOH-mediated suppression of lung clearance of K . pneumoniae was unaffected in nNOS-KO mice and enhanced in the iNOS-KO mice, when compared with that obtained in WT mice . ETOH-stimulated the production of NOS I-derived nitrate and nitrite production by rat brain and lung and inhibited LPS-induced NOS II mRNA, protein, and production of nitrate and nitrite anion . Finally, inhibition of NOS I and NOS I deletion inhibited the in vivo metabolism of ETOH . CONCLUSIONS: We conclude that constitutive NOS I is involved in protection of the lung from stressor-induced lung injury . NOS I within the PMNs may limit PMN recruitment into the lung . Speculatively, NOS II-derived NO may also limit PMN-induced lung damage at the expense of a slower clearance of the bacterial burden. J Med Assoc Thai, 1999 Jul, 82(7), 648 - 53 Efficacy and safety of twice daily administration of cefpirome in the empiric treatment of sepsis; Suwangool P et al.; Cefpirome is a fourth-generation cephalosporin with good activity against both gram-positive and gram-negative bacteria . A multicentre trial was performed to study the efficacy and safety of cefpirome 2 g twice daily in the treatment of sepsis . Sixty-three cases were recruited from 10 hospitals from April 1996 to January 1998 . Fifty seven cases could be evaluated according to the protocol . The APACHE II score was used to measure severity of illness, with 46.9 per cent of patients having APACHE II score more than 10 and two patients more than 20; both were cured . The most common pathogens were gram-negative bacteria with E . coli predominating 16/40 (40.0%), followed by Klebsiella 8/40 (20.0%) . The overall clinical success rates were 54 out of 57 patients (94.7%) . In patients with positive blood culture, the clinical cures were achieved for 20/22 (90.9%) . Cefpirome showed good efficacy and safety in the empirical treatment of suspected bacteremia or sepsis. J Antimicrob Chemother, 1999 Sep, 44(3), 377 - 80 Molecular characterization of a multiply resistant Klebsiella pneumoniae encoding ESBLs and a plasmid-mediated AmpC; Hanson ND et al.; Organisms encoding multiple antibiotic resistance genes are becoming increasingly prevalent . In this report we describe a multiply resistant Klebsiella pneumoniae which possesses at least five different beta-lactamase genes . Isoelectric focusing, polymerase chain reaction and restriction fragment length polymorphism analysis identified TEM-1, multiple SHVs, OXA-9 and a plasmid-mediated ampC, beta-lactamase . Furthermore, Southern analysis and conjugation experiments established that most of the resistance genes were encoded on one large transferable plasmid . This report demonstrates the complexity of multiply resistant organisms. Ann Thorac Surg, 1999 Sep, 68(3), 1058 - 9; discussion 1059-60 Bronchoperitoneal fistula secondary to chronic Klebsiella pneumoniae subphrenic abscess; Stockberger SM Jr et al.; We treated a case of bronchoperitoneal fistula secondary to a Klebsiella pneumoniae subphrenic abscess . This fistulous communication and the surgical procedure used to treat it are described. Mol Microbiol, 1999 Sep, 33(6), 1200 - 9 The sigma 54 DNA-binding domain includes a determinant of enhancer responsiveness; Chaney M et al.; The bacterial sigma54 protein associates with core RNA polymerase to form a holoenzyme that functions in enhancer-dependent transcription . Isomerization of the sigma54 polymerase and its engagement with melted DNA in open promoter complexes requires nucleotide hydrolysis by an enhancer-binding activator . We show that a single amino acid substitution, RA336, in the Klebsiella pneumoniae sigma54 C-terminal DNA-binding domain allows the holoenzyme to isomerize, engage with stably melted DNA and to transcribe from transiently melting DNA without an activator . Activator responsiveness for the formation of stable open complexes remained intact . The activator-independent transcription phenotype of RA336 is shared with mutants in amino-terminal Region I sequences . Thus, in sigma54, two distinct domains function for enhancer responsiveness . A sigma54-DNA contact mediated by R336 appears to be part of a network of interactions necessary for maintaining the transcriptionally inactive state of the holoenzyme . We suggest activator functions to change these interactions and facilitate open complex formation through promoting polymerase isomerization. Int J Immunopharmacol, 1999 Sep, 21(9), 561 - 74 Protective effects of RU 41740, a bacterial immunomodulator, against experimental infections: induction of cytokine and immunoglobulin release in mice after oral administration; Nimier K et al.; RU 41740 (Biostim) is an immunomodulator extracted from Klebsiella pneumoniae (strain O1:K2) . In humans, it is able to reduce the number and duration of infectious exacerbations of chronic bronchitis . Using a mouse model of experimental infection, we found that oral RU 41740 administration strongly protected against gram-negative infections by preventing lethal septicemia, and, to a lesser extent, protected against the gram-positive intracellular pathogen L . monocytogenes . Oral administration of RU 41740 leads to the mobilization of newly dividing T and B cells in the thoracic duct lymph, reflecting the ability of the drug to induce an immune response in gut-associated lymphoid tissue . In cells isolated from mesenteric lymph nodes and spleen, RU 41740 leads to preferential release of the proinflammatory cytokines interleukin (IL)-12 and/or interferon (IFN)-gamma, as well as IL-10, a cytokine involved in inhibiting the synthesis of these latter cytokines . RU 41740 also increases the serum total immunoglobulin (Ig)M concentration and elicits IgM and IgG antibodies against the drug . Infection of mice with Klebsiella pneumoniae has similar functional consequences . Pretreatment of infected mice with RU 41740 leads to a fall in the high levels of proinflammatory cytokines (which could be detrimental), and to an increase in IgG antibodies (which are protective). Proc Natl Acad Sci U S A, 1999 Sep 28, 96(20), 11140 - 4 GTP-dependent activation of urease apoprotein in complex with the UreD, UreF, and UreG accessory proteins; Soriano A et al.; Syntheses of metal-containing enzymes often require the participation of accessory proteins . The roles played by many of these accessory proteins are poorly characterized . Klebsiella aerogenes urease, a nickel-containing enzyme, provides an ideal system to study metallocenter assembly . Here, we describe a method for isolating a complex containing urease apoprotein and the UreD, UreF, and UreG accessory proteins . We demonstrate that urease apoprotein in this complex is activated to near wild-type enzyme levels when incubated with nickel ions and high (approximately 100 mM) concentrations of bicarbonate . Significantly, we also observed nickel-dependent activation at physiologically relevant (approximately 100 microM) bicarbonate levels, but only in the presence of GTP . Based on studies involving a nonhydrolyzable analog of GTP, we conclude that nucleotide hydrolysis, not just binding, is required for this process . The critical nucleotide-binding site was localized to UreG on the basis of experiments using a variant complex . These studies highlight the relevance of the UreD-UreF-UreG-urease apoprotein complex to nickel metallocenter assembly and explain the previously identified in vivo energy requirement for urease activation. Infect Immun, 1999 Oct, 67(10), 5186 - 91 Complement-dependent accumulation and degradation of platelets in the lung and liver induced by injection of lipopolysaccharides; Shibazaki M et al.; We found unique behaviors among platelets within a few minutes of the intravenous injection of lipopolysaccharide (LPS) into mice . Platelets accumulated primarily in the liver at lower doses of LPS, but at higher doses they accumulated largely in the lungs . When the platelets accumulated in these organs were degraded, there was a rapid anaphylactoid shock . The platelet response depended on the strain of mouse and on the source of LPS . Of various LPSs tested, the LPS from the smooth type of Klebsiella O3 (KO3-S LPS) was the most potent at inducing the platelet response and shock . K-76 monocarboxylic acid, an inhibitor of complement C5, effectively prevented the KO3-S LPS-induced degradation (but not accumulation) of platelets and the ensuing rapid shock in BALB/c mice . Moreover, in DBA/2 mice (which are deficient in complement C5), platelets accumulated in the lungs and liver in response to KO3-S LPS but soon returned to the circulation without degradation, and there was no rapid shock . The LPS from the rough type of KO3 induced an accumulation of platelets in the liver and lungs but not a degradation of platelets . On the basis of these results and those reported by other investigators, we propose that in the platelet response to LPS, the lectin pathway to form C3 convertase from C4 and C2 is involved in the rapid accumulation of platelets in the liver and lungs and that the pathway from C5 to C9 is involved in the destruction of platelets and the consequent anaphylactoid shock. J Mol Biol, 1999 Sep 17, 292(2), 203 - 16 RNA sequence requirements for NasR-mediated, nitrate-responsive transcription antitermination of the Klebsiella oxytoca M5al nasF operon leader; Chai W et al.; In Klebsiella oxytoca, enzymes required for nitrate assimilation are encoded by the nasFEDCBA operon . Nitrate and nitrite induction of nasF operon expression is determined by a transcriptional antitermination mechanism, in which the nasR gene product responds to nitrate or nitrite and overcomes transcription termination at the factor-independent terminator site located in the nasF upstream leader region . Previous studies led to the hypothesis that the NasR protein mediates transcription antitermination through interaction with nasF leader RNA . Here, we report a DNA sequence comparison that reveals conserved 1:2 and 3:4 RNA secondary structures in the nasF leader RNAs from two Klebsiella species . Additionally, we found that specific binding of the NasR protein to nasF leader RNA was stimulated by nitrate and nitrite . We combined mutational analysis, in vivo and in vitro antitermination assays, and an RNA electrophoretic mobility shift assay to define regions in the nasF leader that are essential for antitermination and for NasR-RNA interaction . Formation of the 1:2 stem structure and the specific sequence of the 1:2 hexanucleotide loop were required for both nitrate induction and for NasR-RNA interaction . Mutations in the 1:2 stem-loop region that abolished nitrate induction also interfered with NasR-leader RNA interaction . Finally, nucleotide alterations or additions in the linker region between the 1:2 and 3:4 stem-loops were deleterious to nasF operon induction but not to NasR-leader RNA interaction . We hypothesize that NasR protein recognizes the 1:2 stem-loop structure in the nasF leader RNA to mediate transcription antitermination in response to nitrate or nitrite . Plasmid, 1999 Sep, 42(2), 104 - 14 The cassettes and 3' conserved segment of an integron from Klebsiella oxytoca plasmid pACM1; Preston KE et al.; pACM1 is a conjugative multiresistance plasmid from Klebsiella oxytoca that encodes SHV-5 extended-spectrum beta-lactamase (ESBL) and has two integrons . The first is a type I (sul type); the second, detected by hybridization with an intI gene probe, has been putatively identified as a defective type I integron . The cassette region of the first integron has now been fully sequenced and contains three aminoglycoside resistance determinants (aac(6')-Ib, aac(3)-Ia, and ant(3")-Ia) and two open reading frames of unknown function . In addition, sequencing of a region downstream from the qacEDelta1-sulI-ORF 5 gene cluster of the first integron revealed a copy of insertion sequence IS6100 flanked by inverted copies of sequence from the 11.2-kb insert (In2) of Tn21 . This arrangement is similar to that found in In4 of Tn1696 . The coincidence of an ESBL gene and mobile elements on a conjugative plasmid has potential implications for the spread of ESBL-mediated drug resistance, though evidence of bla((SHV-5)) movement mediated by these elements has not been found . Plasmid, 1999 Sep, 42(2), 92 - 103 Restriction map and properties of Klebsiella oxytoca plasmid pACM1; Preston KE et al.; pACM1 is a conjugative multiresistance (putative IncM) plasmid from Klebsiella oxytoca . In order to make a structural and functional map, cloned fragments of pACM1 were systematically isolated from pUC19 libraries using DNA probes from previously cloned fragments . All but approximately 3.6 kb of the plasmid were cloned and a consensus map is presented . Certain pACM1 fragments were "unclonable" (i.e., could not be detected among transformants) unless a 7-kb KpnI fragment was also present in the recombinant construct . Restriction sites found in a portion of the 7-kb KpnI fragment resemble those of the iml determinant region of IncM plasmid R446; therefore, the 7-kb fragment is probably within or includes part of the IncM tra (conjugation) operon . It is probable that pACM1 has loci functionally similar to the kil (lethal) and kor (kill override) loci in the tra operons of IncN or IncP plasmids . pACM1 can be a valuable model for the study of IncM plasmids . Cornea, 1999 Sep, 18(5), 549 - 52 Antibacterial activity of the white precipitate formed on the corneal surface after treatment with ciprofloxacin ophthalmic solution; Madhavan HN et al.; PURPOSE: To determine the antibacterial activity of the white crystalline precipitate formed on the corneal surface after topical administration of 0.3% ciprofloxacin ophthalmic solution by microbiologic assay . METHODS: White crystalline precipitate formed on the corneal surface of seven patients was scraped and individually dissolved in sterile distilled water . Quantification by high-performance liquid chromatography (HPLC) and microbiologic assay of ciprofloxacin in the precipitate solutions were done . Microbiologic assay was performed by agar diffusion method against Klebsiella pneumoniae . RESULTS: By HPLC, concentrations of ciprofloxacin were estimated to be 1.5-60 microg/ml in the dissolved precipitate obtained from six patients, whereas the concentrations based on microbiologic assay varied from 1.6 to 16.1 microg/ml . Ciprofloxacin was not detected by either method in the precipitate obtained from one patient . The antibacterial activity (microg/ml) determined by microbiologic assay was not related to the actual amount of ciprofloxacin in the solutions as estimated by HPLC in cases 1, 2, 4, and 7 . It was almost the same in the solutions from cases 5 and 6 . CONCLUSION: The white crystalline precipitate formed on the corneal surface after topical administration of 0.3% ciprofloxacin ophthalmic solution exhibited bacterial inhibitory activity, indicating that the precipitate may function as a drug depot. Eur J Pediatr, 1999 Sep, 158(9), 740 - 1 Platelet-activating factor concentrations in healthy and septic neonates; Kultursay N et al.; Platelet-activating factor levels were measured in nine preterm infants with Klebsiella pneumonia septicaemia, eight healthy preterm infants of similar gestational age and ten healthy full-term infants of the same postnatal age at sampling . The platelet-activating factor levels of the healthy preterm and term groups did not differ significantly, but were elevated compared to the other two groups in the septic preterm infants (P < 0.01) . Platelet-activating factor levels increase upon stimulation by Gram negative bacteraemia and are a important mediator of neonatal sepsis. Clin Infect Dis, 1999 Aug, 29(2), 352 - 5 Clinical characteristics and molecular epidemiology associated with imipenem-resistant Klebsiella pneumoniae; Ahmad M et al.; Eight patients were infected or colonized with imipenem-resistant Klebsiella pneumoniae (IRKP) from December 1994 to November 1995 . Initial Klebsiella isolates were susceptible to imipenem but resistant to all cephalosporins, aminoglycosides, and beta-lactam inhibitor combinations . All patients had been in the surgical intensive care unit and had undergone abdominal surgery or tracheostomy during hospitalization . The average age of the patients was 71 years (range, 41-81 years) . All patients were treated with imipenem for 5 to 36 days, and IRKP was recovered from each during or after therapy . Pulsed-field gel electrophoresis (PFGE) of the IRKP isolates revealed three distinct clonal patterns . Paired sequential isolates of imipenem-susceptible K . pneumoniae and IRKP from two patients had identical PFGE patterns, suggesting the development of clonal stepwise resistance to imipenem during therapy . Thus, imipenem resistance in Klebsiella may occur when this agent is used for treatment of infection due to ceftazidine- and aminoglycoside-resistant strains. Cytobios, 1999, 98(388), 113 - 23 Resistance to antibiotics, metals, hydrophobicity and klebocinogeny of Klebsiella pneumoniae isolated from foods; Grewal JS et al.; Milk samples and milk products (69 in toto) were screened for the presence of Klebsiella pneumoniae (52%), and maximum isolations (77%) were from ice cream samples (13) . The isolates were hydrophobic, non-haemolytic and possessed both mannose resistant (MR) and mannose sensitive (MS) pili or only MR pili when tested with human or sheep blood, respectively . All isolates were resistant to one metal at least whereas about 98% exhibited resistance to two or more metal ions . The resistance frequency of 93%, 90% and 66.7% was observed against silver (20 micrograms/ml), cadmium (20 micrograms/ml) and mercuric ions (20 micrograms/ml), respectively . Multiple drug resistance (MDR) was observed in 10% of the isolates only . A direct correlation between the metal ion and antibiotic resistance was found in MDR strains . The klebocin typeability of 53% and 61% was observed with 153-158 and 153-156, U-5 and U-6 groups, respectively . The most common typing patterns involved strains 424 (21%) and 442 (31.8%) . Only 61% of the isolates showed enterotoxigenicity by the coagglutination test. Antimicrob Agents Chemother, 1999 Sep, 43(9), 2291 - 4 Influence of cefodizime on pulmonary inflammatory response to heat-killed Klebsiella pneumoniae in mice; Bergeron Y et al.; Encapsulated Klebsiella pneumoniae strains frequently induce fatal nosocomial pneumonia . Cefodizime (CEF) as an antibiotic is suspected to enhance host resistance against various microbial invasions through interactions with bacteria and host cells . To investigate the influence of CEF on the pulmonary response to Klebsiella that does not merely result from direct bacterial clearance by the drug, we inoculated mice with heat-killed fluorescein isothiocyanate-labeled K . pneumoniae . CEF upregulated (P < 0.01) the early Klebsiella-induced secretion of tumor necrosis factor alpha, as well as the number (P < 0.01) and phagocytic efficacy (P < 0.001) of alveolar macrophages . By contrast, the late polymorphonuclear neutrophil recruitment (P < 0.05) and levels of interleukin-1 alpha (IL-1alpha) (P < 0.05) and IL-6 (P < 0.05) were reduced . The stimulation of an early immune response by CEF followed by late reduction in inflammation may be beneficial against bacterial pneumonia. Immunology, 1999 Sep, 98(1), 90 - 7 Exogenous cytokine modulation or neutralization of interleukin-10 enhance survival in lipopolysaccharide-hyporesponsive C3H/HeJ mice with Klebsiella infection; Wang M et al.; Klebsiella pneumoniae has been isolated from liver abscesses in patients with leukaemia or diabetes . The resistance of Klebsiella infection in lipopolysaccharide (LPS)-hyporesponsive mice is unclear . Female C3H/HeJ and C3H/HeN mice, 6-8 weeks old, were intraperitoneally (i.p.) injected with K . pneumoniae . The results showed that C3H/HeJ mice were 24 times more susceptible {lethal dose 50% (LD50) 250 colony-forming units} than C3H/HeN mice to K . pneumoniae infection . C3H/HeJ mice, uninfected or infected with K . pneumoniae, had higher liver interleukin (IL)-10 levels and IL-10 mRNA levels than C3H/HeN mice . Previously, pretreatment with IL-1beta and tumour necrosis factor-alpha (TNF-alpha) protected C3H/HeJ mice from lethal bacterial infection . Therefore the effects of pretreatment with IL-1beta and TNF-alpha or antimurine IL-10 antibody i.p . 1 hr before this infection in both strains of C3H mice were examined . Pretreatment with TNF-alpha or anti-IL-10 antibody enhanced the survival of both strains of mice . TNF-alpha, in combination with IL-1beta, enhanced the survival and bacterial clearance better than single pretreatment in C3H/HeJ mice . Anti-IL-10 antibody increased bacterial clearance and significantly reduced liver cytokine mRNA levels in C3H/HeJ mice more than it did in the controls during infection . These results indicate that exogenous cytokine modulation or neutralization of IL-10 enhance the resistance of LD50 infection in C3H/HeJ mice. J Hosp Infect, 1999 Aug, 42(4), 295 - 302 Nosocomial outbreak of gentamicin-resistant Klebsiella pneumoniae in a neonatal intensive care unit controlled by a change in antibiotic policy; van der Zwet WC et al.; Between August and November 1997, a nosocomial outbreak caused by gentamicin-resistant Klebsiella pneumoniae occurred in the Neonatal Intensive Care Unit (NICU) of our hospital . Thirteen neonates became colonized and three of them became infected . Comparison of the isolates by amplified fragment length polymorphism (AFLP) revealed clonal similarity for isolates of eight neonates (homology > 90%) . Cultures from environmental specimens were negative for gentamicin-resistant K . pneumoniae . A case-control study was conducted to identify risk factors associated with acquisition of gentamicin-resistant K . pneumoniae . Risk factors were low gestational age and birth weight . These neonates need more care and handling and may therefore, be more at risk of colonization . Length of stay on the NICU was significantly longer for cases, but mean time until colonization (6.3 days) was shorter than the total stay for controls (9.5 days) . No single member of the medical or nursing staff was significantly more involved with cases than with controls . The outbreak was stopped by replacing gentamicin by amikacin as the antibiotic of first choice whenever the use of an aminoglycoside antibiotic was indicated. J Bacteriol, 1999 Sep, 181(17), 5296 - 302 A- and T-tract-mediated intrinsic curvature in native DNA between the binding site of the upstream activator NtrC and the nifLA promoter of Klebsiella pneumoniae facilitates transcription; Cheema AK et al.; The nif promoters of Klebsiella pneumoniae must be activated by proteins bound to upstream sequences which are thought to interact with the sigma54-RNA polymerase holoenzyme by DNA looping . NifA is the activator for most of the promoters, and integration host factor (IHF) mediates the DNA looping . While NtrC is the activator for the nifLA promoter, no IHF appears to be involved . There are two A tracts and one T tract between the upstream enhancer and the nifLA promoter . This DNA segment exhibits anomalous electrophoretic mobility, suggesting intrinsic sequence-induced curvature in the DNA . On the one hand, mutation of the A tracts or T tract individually or together, or deletion of the A tracts and the T tract reduces the anomaly; on the other hand, creation of two additional A tracts enhances the anomaly . Intrinsic curvature in the DNA has been confirmed by circular permutation analysis after cloning the DNA fragment in the vector pBend 2 and also by electron microscopy . Computer simulation with the DNA base sequence is also suggestive of intrinsic curvature . A transcriptional fusion with the Escherichia coli lacZ gene of the DNA fragment containing the nifLA promoter and the wild-type or the mutated upstream sequences was constructed, and in vivo transcription in K . pneumoniae and E . coli was monitored . There was indeed very good correlation between the extent of intrinsic curvature of the DNA and transcription from the promoter, suggesting that DNA curvature due to the A tracts and the T tract was necessary for transcription in vivo from the nifLA promoter of K . pneumoniae. J Otolaryngol, 1999 Aug, 28(4), 229 - 31 Laryngeal scleroma; Fajardo-Dolci G et al.; Respiratory scleroma is a chronic, progressive granulomatous disease of the respiratory tract . The causal organism is the Klebsiella rhinoscleromatis . The disease has three stages: the initial catarrhal stage, granulomatous stage, and sclerotic stage . The object of this report was to determine the clinical behaviour of the laryngeal scleroma . The study included 17 patients with this manifestation characterized by airway obstruction and dysphonia . The report revealed that respiratory scleroma affected the larynx in 40%, and the principal findings were glottic/subglottic stenosis. J Biol Chem, 1999 Aug 27, 274(35), 25159 - 66 Properties of a cyclodextrin-specific, unusual porin from Klebsiella oxytoca; Pajatsch M et al.; The function of CymA, 1 of the 10 gene products involved in cyclodextrin uptake and metabolism by Klebsiella oxytoca, was characterized . CymA is essential for growth on cyclodextrins, but it can also complement the deficiency of a lamB (maltoporin) mutant of Escherichia coli for growth on linear maltodextrins, indicating that both cyclic and linear oligosaccharides are accepted as substrates . CymA was overproduced in E . coli and purified to apparent homogeneity . CymA is a component of the outer membrane, is processed from a signal peptide-containing precursor, and possesses a high content of antiparallel beta-sheet . Incorporation of CymA into lipid bilayers and conductance measurements revealed that it forms ion-permeable channels, which exhibit a substantial current noise . CymA-induced membrane conductance decreased considerably upon addition of alpha-cyclodextrin . Titration experiments allowed the calculation of a half-saturation constant, K(S), of 28 microM for its binding to CymA . CymA assembled in vitro to two-dimensionally crystalline tubular membranes, which, on electron microscopy, are characterized by a p1-related two-sided plane group . The crystallographic unit cell contains four monomeric CymA molecules showing a central pore . The lattice parameters are a = 16.1 nm, b = 3.8 nm, gamma = 93 degrees . CymA does not form trimeric complexes in lipid membranes and shows no tendency to trimerize in solution . CymA thus is an atypical porin with novel properties specialized to transfer cyclodextrins across the outer membrane. Clin Infect Dis, 1999 May, 28(5), 1134 - 8 Successful treatment of ceftazidime-resistant Klebsiella pneumoniae ventriculitis with intravenous meropenem and intraventricular polymyxin B: case report and review; Segal-Maurer S et al.; Increasing prevalence of multidrug-resistant gram-negative organisms has led to a rise in clinically significant infections with these organisms and an increasing therapeutic dilemma . We present a case of a neurosurgical patient who developed ventriculoperitoneal shunt-associated ventriculitis due to ceftazidime-resistant Klebsiella pneumoniae susceptible to cefepime, imipenem, meropenem, and polymyxin B only . Successful management was accomplished by removal of the shunt and therapy with systemic meropenem and intraventricular polymyxin B . Rapid cerebrospinal fluid (CSF) sterilization occurred, with CSF bactericidal titers of 1:32 to 1:128 . Polymyxin B should be considered as adjunctive therapy for life-threatening multidrug-resistant gram-negative infections . Prior literature on use of intrathecal polymyxin B in therapy for meningitis supports its potential efficacy. J Protein Chem, 1999 May, 18(4), 489 - 95 The amino acid sequence of ribitol dehydrogenase-F, a mutant enzyme with improved xylitol dehydrogenase activity; Homsi-Brandeburgo MI et al.; A mutant ribitol dehydrogenase (RDH-F) was purified from Klebsiella aerogenes strain F which evolved from the wild-type strain A under selective pressure to improve growth on xylitol, a poor substrate used as sole carbon source . The ratio of activities on xylitol (500 mM) and ribitol (50 mM) was 0.154 for RDH-F compared to 0.033 for the wild-type (RDH-A) enzyme . The complete amino acid sequence of RDH-F showed the mutations . Q60 for E60 and V215 for L215 in the single polypeptide chain of 249 amino acid residues . Structural modeling based on homologies with two other microbial dehydrogenases suggests that E60 --> Q60 is a neutral mutation, since it lies in a region far from the catalytic site and should not cause structural perturbations . In contrast, L215 --> V215 lies in variable region II and would shift a loop that interacts with the NADH cofactor . Another improved ribitol dehydrogenase, RDH-D, contains an A196 --> P196 mutation that would disrupt a surface alpha-helix in region II . Hence conformational changes in this region appear to be responsible for the improved xylitol specificity. Mol Microbiol, 1999 Aug, 33(4), 873 - 85 Involvement of the sigmaN DNA-binding domain in open complex formation; Oguiza JA et al.; sigmaN (sigma54) RNA polymerase holoenzyme closed complexes isomerize to open complexes in a reaction requiring nucleoside triphosphate hydrolysis by enhancer binding activator proteins . Here, we characterize Klebsiella pneumoniae sigmaN mutants, altered in the carboxy DNA-binding domain (F354A/F355A, F402A, F403A and F402A/F403A), that fail in activator-dependent transcription . The mutant holoenzymes have altered activator-dependent interactions with promoter sequences that normally become melted . Activator-dependent stable complexes accumulated slowly in vitro (F402A) and to a reduced final level (F403A, F402A/F403A, F354A/F355A) . Similar results were obtained in an assay of activator-independent stable complex formation . Premelted templates did not rescue the mutants for stable preinitiation complex formation but did for deleted region I sigmaN, suggesting different defects . The DNA-binding domain substitutions are within sigmaN sequences previously shown to be buried upon formation of the wild-type holoenzyme or closed complex, suggesting that, in the mutants, alteration of the sigmaN-core and sigmaN-DNA interfaces has occurred to change holoenzyme activity . Core-binding assays with the mutant sigmas support this view . Interestingly, an internal deletion form of sigmaN lacking the major core binding determinant was able to assemble into holoenzyme and, although unable to support activator-dependent transcription, formed a stable activator-independent holoenzyme promoter complex on premelted DNA templates. Mol Microbiol, 1999 Aug, 33(4), 858 - 72 The periplasmic domain of the histidine autokinase CitA functions as a highly specific citrate receptor; Kaspar S et al.; The two-component regulatory system CitA/CitB is essential for induction of the citrate fermentation genes in Klebsiella pneumoniae . CitA represents a membrane-bound sensor kinase consisting of a periplasmic domain flanked by two transmembrane helices, a linker domain and the conserved kinase or transmitter domain . A fusion protein (MalE-CitAC) composed of the maltose-binding protein and the CitA kinase domain (amino acids 327-547) showed constitutive autokinase activity and transferred the gamma-phosphate group of ATP to its cognate response regulator CitB . The autokinase activity of CitA was abolished by an H350L exchange, and phosphorylation of CitB was inhibited by a D56N exchange, indicating that H-350 and D-56 represent the phosphorylation sites of CitA and CitB respectively . In the presence of ATP, CitB-D56N formed a stable complex with MalE-CitAC . To analyse the sensory properties of CitA, the periplasmic domain (amino acids 45-176) was overproduced as a soluble, cytoplasmic protein with a C-terminally attached histidine tag (CitAPHis) . Purified CitAPHis bound citrate, but none of the other tri- and dicarboxylates tested, with high affinity (KD approximately 5 microM at pH 7) in a 1:1 stoichiometry . As shown by isothermal titration calorimetry, the binding reaction was driven by the enthalpy change (DeltaH = -76.3 kJ mol-1), whereas the entropy change was opposed (-TDeltaS = + 46.3 kJ mol-1) . The pH dependency of the binding reaction indicated that the dianionic form H-citrate2- is the citrate species recognized by CitAPHis . In the presence of Mg2+ ions, the dissociation constant increased significantly, suggesting that the Mg-citrate complex is not bound by CitAPHis . This work defines the periplasmic domain of CitA as a highly specific citrate receptor and elucidates the binding characteristics of CitAPHis. Biochemistry, 1999 Aug 3, 38(31), 9906 - 13 Klebsiella pneumoniae nitrogenase: formation and stability of putative beryllium fluoride-ADP transition state complexes; Clarke TA et al.; Incubation of the MoFe protein (Kp1) and Fe protein (Kp2), the component proteins of Klebsiella pneumoniae nitrogenase, with BeF(3)(-) and MgADP resulted in a progressive inhibition of nitrogenase activity . We have shown that at high Kp2 to Kp1 molar ratios this inhibition is due to the formation of an inactive complex with a stoichiometry corresponding to Kp1 . inverted question markKp2.(MgADP.BeFx)2 inverted question mark2 . At lower Kp2:Kp1 ratios, an equilibrium between this 2:1 complex, the partially active 1:1 Kp1.Kp2.(MgADP . BeFx)2 complex, and active nitrogenase components was demonstrated . The inhibition was reversible since incubation of the 1:1 complex in the absence of MgADP and beryllium resulted in complete restoration of activity over 30 h . Under pseudo-first-order conditions with regard to nitrogenase components and MgADP, the kinetics of the rate of inhibition with increasing concentrations of BeF(3)(-) showed a square dependence on {BeF(3)(-)}, consistent with the binding of two Be atoms by Kp2 in the complex . Analytical fplc gel filtration profiles of Kp1.Kp2 incubation mixtures at equilibrium resolved the 2:1 complex and the 1:1 complex from free Kp1 . Deconvolution of the equilibrium profiles gave concentrations of the components allowing constants for their formation of 2.1 x 10(6) and 5.6 x 10(5) M(-1) to be calculated for the 1:1 and 2:1 complexes, respectively . When the active site concentration of the different species was taken into account, values for the two constants were the same, indicating the two binding sites for Kp2 are the same for Kp1 with one or both sites unoccupied . The value for K(1) we obtain from this study is comparable with the value derived from pre-steady-state studies of nitrogenase . Analysis of the elution profile obtained on gel filtration of a 1:1 ratio incubation mixture containing 20 microM nitrogenase components showed 97% of the Kp2 present initially to be complexed . These data provide the first unequivocal demonstration that Fe protein preparations which may contain up to 50% of a species of Fe protein defective in electron transfer is nevertheless fully competent in complex formation with MoFe protein. Acta Otorrinolaringol Esp, 1999 May, 50(4), 321 - 3 {Rhinoscleroma . A case report}; Valor Garcia C et al.; Rhinoscleroma is a chronic, specific, inflammatory granulomatous condition of the nose and other structures of the upper respiratory tract . It is caused by the bacterium Klebsiella rhinoscleromatis . We report a case in a 29-year-old black male emigrant who consulted for a 2-year history of hoarseness, cough, and nasal discharge . The diagnosis was scleroma with nasal, laryngeal, tracheal, and bronchial involvement and ulcerating and necrotizing lesions that caused respiratory obstruction . Bacterial over-infection responded to treatment with third-generation cephalosporins and clindamycin . The sclerotic lesions responded well to treatment with ciprofloxacin . We review the clinical findings at different stages, diagnostic options, and several treatments. Rev Alerg Mex, 1999 May-Jun, 46(3), 66 - 71 {Klebsiella pneumoniae glycoproteins as coadjuvants in the prevention of recurrent respiratory infections in children 1-6 years of age}; Arroyave CM; MATERIAL AND METHOD: Forty two children with clinical diagnosis of recurrent high and low respiratory infections, were treated with an extract of P1 and F1 glycoproteins; fraction of Klebsiella pneumoniae, 1 g/day for one week a month for three months, according to a double-blind, randomized, parallel group trial . RESULTS: Improvement of clinical and laboratory results were compared with 44 control patients with the same age and similar sex distribution, that were treated with placebo . At the end of study, clinical analysis at 6, 9 and 12 months after the initial dose of Klebsiella pneumoniae, decreased in the number of respiratory infections, sick days, and school assistance were observed in the study group when compared with the control group (p < 0.001 in all parameters) . There were not statistical significant changes in hemolytic complement, C3, C4 and immunoglobulins (IgA, IgG, IgM and IgE) levels before and after treatment and between groups . There were not observed adverse reactions to oral treatment with this extract of Klebsiella pneumoniae . CONCLUSIONS: These results suggested that the extract of Klebsiella can be used as a coadjuvant in the treatment of pediatric patients with recurrent high and low respiratory infections. Pathol Biol (Paris), 1999 May, 47(5), 405 - 7 {Klebsiella oxytoca septicemia following platelet transfusion}; Boyeldieu D et al.; Two fractions of a three-day-old apheresis platelet collection from a known habitual donor were transfused to two children with thrombocytopenia and bleeding . Both patients developed evidence of severe infection during the transfusion . One died despite intensive care and antimicrobial therapy . The other, whose transfusion was cut short, recovered . A Klebsiella oxytoca strain was recovered from the two transfusion bags, from a third unused bag, and from blood samples from the patient who died . Genotyping results established that all these isolates were identical . Tests for K . oxytoca were negative on the batches of blood donation material, the bottle of antiseptic used, and throat and stool specimens from the donor and phlebotomists . The most likely hypothesis is that the donor developed transient asymptomatic bacteremia during the 136-minute-long collection procedure and that the organism subsequently grew in the platelet collections, which were kept at 20-24 degrees C with agitation for three days before being used. Plasmid, 1999 Jul, 42(1), 53 - 9 Conditionally lethal genes in the N pilus region of plasmid pCU1; Holcik M et al.; Plasmid genes or regions that are conditionally lethal to Escherichia coli have been called kil and those lethal to Klebsiella but not to E . coli have been called kik . Both classes of genes are found in or close to the N pilus region of the plasmid pCU1 and the closely related plasmid pKM101 . Here we describe two new and overlapping lethal genes that are located between kikA and traA of the plasmid pCU1 and display host specificity . KilC is lethal in E . coli and Klebsiella while kikC is lethal only in Klebsiella . The previously identified korA gene is sufficient to override the lethality of kilC in trans or in cis but is insufficient to override kikC . kilC expression in E . coli leads to cell death accompanied by an increase in average cell length without affecting septum formation . Int Surg, 1999 Apr-Jun, 84(2), 144 - 50 Mucosa-associated lymphoid tissue (MALT) of the gallbladder: a clinicopathological correlation; Tomori H et al.; OBJECTIVE: Lymph follicles are frequently found on histological examination of a surgically removed gallbladder . The significance of these lymph follicles is not clearly understood . The aim of this study was to examine the clinicopathological correlation between the lymph follicles in the gallbladder morphologically and the mucosa-associated lymphoid tissue (MALT) in the gut . METHODS: The gallbladders were fixed and cut serially . The tissue slices were processed in the routine manner for a histological examination . The histological criteria for MALT in this study was defined as the presence of lymph follicles with germinal centers in the lamina propria mucosae in approximately equal numbers in all portions of the gallbladders from the neck to the fundus . Biliary bile obtained at surgery was cultured for a bacteriological examination in the hospital laboratory . The types of gallstones were classified according to the Classification of Gallstones by the Japanese Society of Gastroenterology . RESULTS: Of the 1341 patients, 158 (11.8%) patients fulfilled the histological criteria, including 64 men and 94 women with an average age of 64.2 years . Gallstones were present in 89.2% of the patients, and 74.5% of these were calcium bilirubinate gallstones . Cultures of the bile were positive in 95.4% of the patients . A variety of bacterial species were thus found, most commonly Escherichia coli and Klebsiella spp . Grossly, the gallbladders usually showed a granular appearance of the mucosa . CONCLUSION: The MALT in the gallbladder is not a rare condition and is frequently encountered in clinical practice . This lymphoid tissue may represent a mucosal and morphological immune phenomenon for infection rather than a substrate for the development of low-grade B-cell lymphoma. Laryngorhinootologie, 1999 Apr, 78(4), 200 - 3 {Rhinoscleroma: a case report}; Issing WJ et al.; BACKGROUND: Rhinoscleroma is a rare infectious disease of the upper respiratory tract caused by Klebsiella rhinoscleromatis . The nasal mucosa represents the primary region of occurrence which is most likely a result of respiratory transmission . Without adequate++ treatment, the disease can potentially spread to the rest of the upper and middle respiratory tract within a period of several years . Healing often occurs with extensive scarring and adhesions of the nose, palate and larynx . A life threatening late stage manifestation includes subglottic stenosis requiring immediate surgical intervention . Medical treatment primarily consists of a long-term course of antibiotics . Ciprofloxacin (Fluoroquinolon) has proved to be one of the most effective drugs . CASE REPORT: We report about a 33 year-old Egyptian male, who presented in our department with a 10 year history of a previously, only temporarily successfully treated rhinoscleroma . His main symptoms were nasal obstruction, epistaxis and inspiratory stridor . FINDINGS: We began treatment with Ciprofloxacin over a four week period, which lead to an improvement of his symptoms . The treatment was considered complete after several biopsies and smears were negative for live specimens . We then chose to reduce the scar tissue that was causing obstruction in the larynx and the nose . CONCLUSION: The rhinoscleroma is a rare disease in geographic areas with poor hygiene and can mimic several other infectious and malignant diseases . Treatment should include a long-term antimicrobial therapy and surgical intervention in cases with symptomatic obstruction. J Bacteriol, 1999 Jul, 181(14), 4397 - 403 Isolation and characterization of mutations in the Escherichia coli regulatory protein XapR; Jorgensen C et al.; In this work, the LysR-type protein XapR has been subjected to a mutational analysis . XapR regulates the expression of xanthosine phosphorylase (XapA), a purine nucleoside phosphorylase in Escherichia coli . In the wild type, full expression of XapA requires both a functional XapR protein and the inducer xanthosine . Here we show that deoxyinosine can also function as an inducer in the wild type, although not to the same extent as xanthosine . We have isolated and characterized in detail the mutants that can be induced by other nucleosides as well as xanthosine . Sequencing of the mutants has revealed that two regions in XapR are important for correct interactions between the inducer and XapR . One region is defined by amino acids 104 and 132, and the other region, containing most of the isolated mutations, is found between amino acids 203 and 210 . These regions, when modelled into the three-dimensional structure of CysB from Klebsiella aerogenes, are placed close together and are most probably directly involved in binding the inducer xanthosine. Biotechnol Bioeng, 1999 Jul 20, 64(2), 168 - 73 Application of factorial designs for optimization of cyclodextrin glycosyltransferase production from Klebsiella pneumoniae pneumoniae AS-22; Gawande BN et al.; Production of cyclodextrin glycosyltransferase (CGTase) from Klebsiella pneumoniae pneumoniae AS-22 was optimized in shake flasks using a statistical experimental design approach . Effect of various components in the basal medium, like carbon, nitrogen, phosphorus, and mineral sources as well as initial pH and temperature, were tested on enzyme production . The optimum concentrations of the selected media components were determined using statistical experimental designs . Two level fractional factorial designs in five variables, namely, dextrin, peptone, yeast extract, ammonium dihydrogen orthophosphate, and magnesium sulphate concentrations were constructed . The optimum medium composition thus found consisted of 49.3 g/L dextrin, 20.6 g/L peptone, 18.3 g/L yeast extract, 6.7 g/L ammonium dihydrogen orthophosphate, and 0.5 g/L magnesium sulphate . The maximum CGTase activity obtained was 21.4 U/mL in 28 h of incubation . The cell growth and CGTase production profiles were studied with the optimized medium in shake flasks and in 1-L fermenters . It was observed that the enzyme production was growth associated both in shake flask and in fermenter, although it was slower in shake flask . The maximum CGTase activity obtained in the fermenter was 32.5 U/mL in 16 h . The optimized medium resulted in about 9-fold increase in the enzyme activity as compared to that obtained in the basal medium in shake flask as well as in fermenter . J Mass Spectrom, 1999 Jun, 34(6), 622 - 36 Mass spectrometric analysis of Klebsiella pneumoniae ssp . pneumoniae rough strain R20 (O1-: K20-) lipopolysaccharide preparations: identification of novel core oligosaccharide components and three 3-deoxy-D-manno-oct-2-ulopyranosonic artifacts; Olsthoorn MM et al.; In an attempt to find the best approach for the mass spectrometric analysis of the whole range of lipopolysaccharide (LPS) structures from Klebsiella pneumoniae ssp . pneumoniae rough strain R20 (O1-:K20-), various methods of LPS preparation were applied and the products were analyzed using a range of mass spectrometric techniques . The most productive approach proved to be the removal of lipid A by mild acid hydrolysis and the study of the core oligosaccharide structures using nanoelectrospray time-of-flight mass spectrometry (TOF-MS) in combination with collision-induced dissociation tandem mass spectrometry . This procedure is very sensitive, but results in the generation of a reducing 3-deoxy-D-manno-oct-2-ulopyranosonic acid residue (Kdo) that is susceptible to the formation of artifacts, which give rise to pseudomolecular ions 18, 46, and 88 Da below the pseudomolecular ion for the unmodified species . Alternatively, matrix-assisted laser desorption/ionization TOF-MS combined with post-source decay can be used to study the de-O-acylated LPS preparation and especially to identify those residues bearing phosphate groups and the residues involved in the linkage between the core and lipid A . In addition to the five LPS core structures defined using NMR spectroscopy by Susskind et al., several extra related LPS structure were identified . Larger LPS species were observed, which surprisingly do not represent species containing longer versions of the novel Klebsiella heptoglycan, but instead are species having the defined core and heptoglycan extended with up to three extra hexuronic acid and one or two extra hexose residues. Proc Natl Acad Sci U S A, 1999 Jul 6, 96(14), 8173 - 7 Secretin PulD: association with pilot PulS, structure, and ion-conducting channel formation; Nouwen N et al.; The outer membrane protein PulD (secretin) of Klebsiella oxytoca is required for transport of pullulanase across this membrane . We have purified a multimeric PulD complex from an Escherichia coli strain expressing all the proteins involved in pullulanase secretion . The outer membrane-anchored lipoprotein PulS was found to copurify with PulD . The molar ratio of the two proteins is close to 1:1, and the size of the complex is approximately 1 MDa . Scanning transmission electron and cryo-electron microscopy analyses showed that the purified complex is a cylindrical structure having a central cavity of approximately 7.6 nm and peripheral radial spokes . Fusion of proteoliposomes containing the purified complex with a planar lipid bilayer resulted in the appearance of small, voltage-activated, ion-conducting channels . We conclude that the central cavity seen in the electron microscope is part of a large gated channel and propose that the observed current fluctuations correspond to voltage-induced, relatively minor displacements of domains in the purified complex rather than to a complete opening of the secretin channel. Antimicrob Agents Chemother, 1999 Jul, 43(7), 1669 - 73 Roles of beta-lactamases and porins in activities of carbapenems and cephalosporins against Klebsiella pneumoniae; Martinez-Martinez L et al.; Two clinical isolates of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae were noted to be less susceptible than expected to imipenem . Both were missing outer membrane proteins that serve as channels for antibiotic entry . The role of beta-lactamase in resistance was investigated by eliminating the original ESBL and introducing plasmids encoding various ESBLs and AmpC beta-lactamase types, by studying the effect of an increased inoculum, and by evaluating interactions with beta-lactamase inhibitors . The contribution of porin deficiency was investigated by restoring a functional ompK36 gene on a plasmid . Plasmids encoding AmpC-type beta-lactamases provided resistance to imipenem (up to 64 microg/ml) and meropenem (up to 16 microg/ml) in strains deficient in porins . Carbapenem resistance showed little inoculum effect, was not affected by clavulanate but was blocked by BRL 42715, and was diminished if OmpK36 porin was restored . Plasmids encoding TEM- and SHV-type ESBLs conferred resistance to cefepime and cefpirome, as well as to earlier oxyimino-beta-lactams . This resistance was magnified with an increased inoculum, was blocked by clavulanate, and was also lowered by OmpK36 porin restoration . In addition, SHV-2 beta-lactamase had a small effect on carbapenem resistance (imipenem MIC, 4 microg/ml, increasing to 16 microg/ml with a higher inoculum) when porins were absent . In K . pneumoniae porin loss can thus augment resistance provided either by TEM- or SHV-type ESBLs or by plasmid-mediated AmpC enzymes to include the latest oxyimino-beta-lactams and carbapenems. Antimicrob Agents Chemother, 1999 Jul, 43(7), 1657 - 61 Molecular characterization of TEM-59 (IRT-17), a novel inhibitor-resistant TEM-derived beta-lactamase in a clinical isolate of Klebsiella oxytoca; Bermudes H et al.; A clinical isolate of Klebsiella oxytoca (Kox 443) was found to have a low-level resistance to broad-spectrum penicillins (MICs of amoxicillin and ticarcillin, 256 and 32 microg/ml, respectively), without substantial potentiation by 2 microg of clavulanic acid per ml (amoxicillin- and ticarcillin-clavulanate, 128 and 8 microg/ml, respectively), while being fully susceptible to cephalosporins and other beta-lactam antibiotics . These resistances were carried by a ca . 50-kb conjugative plasmid that encodes a single beta-lactamase with a pI of 5.6 . Compared to TEM-2, this enzyme exhibited a 3- to 30-fold higher Km and a decreased maximal hydrolysis rate for beta-lactams; higher concentrations of suicide inactivators (5- to 500-fold higher concentrations giving a 50% reduction in hydrolysis) were required for inhibition . Nucleotide sequence analysis revealed identity between the blaTEM gene of Kox 443 and the blaTEM-2 gene, except for a single A-to-G change at position 590, leading to the amino acid change from Ser-130 Gly . This mutation has not been reported previously in the TEM type beta-lactamases produced by clinical strains, and the novel enzyme was called TEM-59 (alternative name IRT-17) . This is the first description of an inhibitor-resistant TEM-derived enzyme in the species K . oxytoca. Indian J Public Health, 1998 Jan-Mar, 42(1), 9 - 14 Early neonatal morbidity and mortality in a city based medical college nursery; Das PK et al.; Early neonatal morbidity & mortality were studied in 7972 viable live born babies over one year period in Medical College, Calcutta . Early neonatal morbidity and mortality rate were 66.85 & 32.86 respectively . About 48% of Early neonatal deaths occurred in 1st 48 hours & 80% within first 72 hours of life . Early neonatal mortality rate per 1000 was maximum in babies born of a primi (43.03) and grand multiparous mother (103.89); maternal age less than 20 yrs . (44.15), and more than 30 yrs . (46.04) & in multiple pregnancy (142.85) . It was highest in breech delivery (114.28) & with maternal disease like dribling (179), hypertension (146) & APH (116) . Birth asphyxia contributed 65.26% of early neonatal deaths, followed by septicaemia (10.3%) . Klebsiella was the most common (55%) organismPIP: Morbidity and mortality in the first 7 days of life were investigated in a prospective study of the 7972 viable live births at the Eden Hospital Nursery in Calcutta, India, in a 22-month period in 1995-96 . The early neonatal mortality rate was 32.86/1000 and the morbidity rate was 66.85/1000 . 48.8% of these deaths occurred in the first 24 hours of life and 80% within 72 hours . In 67.7% of deaths, there had been no antenatal care . Overall, 28.34% of infants were low birth weight; however, these infants comprised 77.8% of early neonatal deaths . The highest neonatal mortality rates were recorded in babies of primiparas (43.03), grand multiparas (103.89), mothers under 20 years of age (44.15) or over 30 years of age (46.04), and those with nonsingleton births (142.85) and breech deliveries (114.28) . Birth asphyxia was the most common cause of neonatal mortality (65.26%); another 10.30% of deaths involved septicemia . Klebsiella was the most commonly isolated organism (55.27%) in septicemic neonates . Reductions in the incidence of low-birth-weight deliveries through measures such as community-level educational outreach could have a significant impact on the prevention of early neonatal mortality and morbidity in India . J Bacteriol, 1999 Jul, 181(13), 4110 - 3 Identification and expression of the genes encoding a reactivating factor for adenosylcobalamin-dependent glycerol dehydratase; Tobimatsu T et al.; Adenosylcobalamin-dependent glycerol dehydratase undergoes inactivation by glycerol, the physiological substrate, during catalysis . In permeabilized cells of Klebsiella pneumoniae, the inactivated enzyme is reactivated in the presence of ATP, Mg2+, and adenosylcobalamin . We identified the two open reading frames as the genes for a reactivating factor for glycerol dehydratase and designated them gdrA and gdrB . The reactivation of the inactivated glycerol dehydratase by the gene products was confirmed in permeabilized recombinant Escherichia coli cells coexpressing GdrA and GdrB proteins with glycerol dehydratase. J Bacteriol, 1999 Jul, 181(13), 4004 - 11 Membrane association and multimerization of secreton component pulC; Possot OM et al.; The PulC component of the Klebsiella oxytoca pullulanase secretion machinery (the secreton) was found by subcellular fractionation to be associated with both the cytoplasmic (inner) and outer membranes . Association with the outer membrane was independent of other secreton components, including the outer membrane protein PulD (secretin) . The association of PulC with the inner membrane is mediated by the signal anchor sequence located close to its N terminus . These results suggest that PulC forms a bridge between the two membranes that is disrupted when bacteria are broken open for fractionation . Neither the signal anchor sequence nor the cytoplasmic N-terminal region that precedes it was found to be required for PulC function, indicating that PulC does not undergo sequence-specific interactions with other cytoplasmic membrane proteins . Cross-linking of whole cells resulted in the formation of a ca . 110-kDa band that reacted with PulC-specific serum and whose detection depended on the presence of PulD . However, antibodies against PulD failed to react with this band, suggesting that it could be a homo-PulC trimer whose formation requires PulD . The data are discussed in terms of the possible role of PulC in energy transduction for exoprotein secretion. J Antimicrob Chemother, 1999 May, 43(5), 715 - 8 Co-amoxiclav affects cytokine production by human polymorphonuclear cells; Reato G et al.; Some antimicrobial agents have been reported to modify the host immune responses both in vivo and in vitro . As we demonstrated previously that co-amoxiclav had beneficial properties which result in enhancement of the microbicidal functions of human poly-morphonuclear cell (PMNs), we investigated the modulatory effect of this combination on cytokine production by human PMNs in vitro . The addition of co-amoxiclav elic