Pseudomonas aeruginosa

Antimicrob Agents Chemother, 1996 Jan, 40(1), 247 - 52
Influence of antibiotic and E5 monoclonal immunoglobulin M interactions on endotoxin release from Escherichia coli and Pseudomonas aeruginosa; Lamp KC et al.; Recent controversy surrounding the activity of monoclonal antibodies against endotoxin highlights the necessity of identifying all factors associated with increased mortality, one of which is endotoxin concentrations . Antibiotics may induce different patterns of endotoxin release . We compared the release of free endotoxin (in endotoxin units per milliliter) over 6 h and changes in numbers of CFU of exponentially growing Escherichia coli and Pseudomonas aeruginosa (10(6) to 10(7) CFU/ml) cultured in chemically defined endotoxin-free broth combined with pooled human serum and/or 10 micrograms of E5 immunoglobulin M monoclonal antibody per ml . MICs and MBCs were tested in each medium at the same inoculum . The inoculum was exposed to antibiotics at a single fixed multiple of the MIC for each medium (range, two to eight times the MIC) . E5 antibody had no effect on MICs, MBCs, bactericidal activity, or endotoxin release . In the presence of 50% serum, amikacin, ceftazidime, imipenem, and ofloxacin each killed equivalent amounts of E . coli over 6 h; however, ceftazidime induced the highest release of endotoxin . Amikacin and ofloxacin produced the most favorable ratio of endotoxin release to amount of bacterial killing . In the presence of 50% serum, ceftazidime and imipenem reduced the P . aeruginosa inoculum to the greatest extent over 6 h . Although its bactericidal activity was diminished, ofloxacin caused the lowest release of free endotoxin . Imipenem and ofloxacin showed similar low ratios of endotoxin release to bacterial killing . In summary, antibiotic class, presence of serum, and type of organism influenced bactericidal activity and endotoxin release.

Antimicrob Agents Chemother, 1996 Jan, 40(1), 61 - 4
Serum bactericidal activity of ceftazidime: continuous infusion versus intermittent injections; Nicolau DP et al.; Since beta-lactam antibiotics have concentration-independent killing, bacterial eradication is a function of the time the serum drug concentration remains above the drug's MIC (T > MIC) . We compared the serum bactericidal titers (SBTs) of ceftazidime given by continuous infusion (CI) or by intermittent bolus dosing (BD) against two clinical isolates each of Pseudomonas aeruginosa and Escherichia coli to determine if CI would allow lower daily dosing while still providing equal bactericidal activity compared with BD . This was an open-labeled, randomized, steady-state, four-way crossover study with 12 healthy volunteers . The ceftazidime regimens were 1 g every 8 h (q8h) BD, 1 g q12h BD, 3 g over 24 h CI, and 2 g over 24 h CI . The areas under the bactericidal curves were calculated by the trapezoidal rule using the reciprocal of the SBT . For all organisms the areas under the bactericidal curves for intermittent versus the CI regimens were the same for equal doses (P > 0.05) . For both strains of E . coli all four regimens provided SBTs of > or = 1:2 over the dosing interval and 100% T > MIC . The 1-g q8h BD and q12h BD regimens provided T > MIC of 82 and 52%, respectively, for both P . aeruginosa isolates (MICs, 4 micrograms/ml) . In comparison, the 2- and 3-g CI regimens always maintained SBTs of > or = 1:2 and T > MIC over the 24-h period as serum drug concentrations were 12.8 +/- 3.0 and 18.2 +/- 4.5 micrograms/ml, respectively . CI optimizes the pharmacodynamic and pharmacoeconomic profile of ceftazidime by providing adequate antibacterial activity over the 24-h dosing period with a reduction in the total daily dose of the antimicrobial agent.

Antimicrob Agents Chemother, 1996 Jan, 40(1), 35 - 9
Influence of pH on adaptive resistance of Pseudomonas aeruginosa to aminoglycosides and their postantibiotic effects; Xiong YQ et al.; Adaptive resistance to aminoglycosides in Pseudomonas aeruginosa and other gram-negative bacilli is usually induced by the initial exposure to the drug . We investigated the influence of pH on the adaptive resistance of a clinical P . aeruginosa strain to aminoglycosides in vitro and on their postantibiotic effects . For adaptive resistance, the first-exposure concentrations of both amikacin and netilmicin were one, two, four, and eight times the MIC of each drug and the second-exposure concentrations were two times the MIC of each drug . Adaptive resistance was greater and more prolonged with higher initial aminoglycoside concentrations, and the bactericidal effects of the aminoglycosides were concentration dependent at pH 7.4 . At pH 6.5, the killing rates of amikacin and netilmicin were far lower than those observed at pH 7.4 . At pH 5.5, amikacin and netilmicin exerted practically no bactericidal effect on the P . aeruginosa strain used . However, with media at pH 5.5 and 6.5, adaptive resistance of P . aeruginosa preexposed to amikacin and netilmicin was also clearly exhibited, with the degree of adaptive resistance depending on the bactericidal effects of both drugs on nonpreexposed controls . Maximal adaptive resistance occurred between 0 and 4 h after preexposure . The postantibiotic effects of amikacin and netilmicin against the P . aeruginosa strain were shown to be concentration dependent and were reduced at acidic pHs . No changes in outer and inner membrane proteins occurred during the adaptive-resistance interval.

Am J Physiol, 1996 Jan, 270(1 Pt 2), R207 - 16
Changes in regional hemodynamics after nitric oxide inhibition during ovine bacteremia; Lingnau W et al.; We studied the action of nitric oxide synthase (NOS) inhibition on changes in regional blood flow during a continuous infusion of live bacteria . Eighteen ewes were chronically instrumented . After a 7-day recovery period, an infusion of 10(6) colony-forming units/min Pseudomonas aeruginosa was begun . At 24 h, cardiac output increased significantly above baseline in all groups (5.9 +/- 0.4 vs . 8.2 +/- 0.6 l.min 1.m-2), systemic vascular resistance decreased (1,362 +/- 120 vs . 821 +/- 145 dyn.g.cm-5.m-2), and cerebral, cephalic mesenteric, and hindlimb blood flows increased . The animals were then equally and randomly assigned to a bolus of a NOS inhibitor, either 25 mg/kg N omega-nitro-L-arginine methyl ester (L-NAME) or 20 mg/kg N omega-monomethyl-L-arginine (L-NMMA), followed by a continuous infusion of 7 mg.kg-1.min-1 L-NMMA or saline . After NOS inhibition, cardiac index decreased {5.6 +/- 0.1 (L-NAME) and 5.5 +/- 0.4 l.min-1.m-2 (L-NMMA)} and remained significantly decreased for 12 h . 1-NAME decreased carotid and mesenteric blood flows to 64% of the preseptic baseline, and they remained below baseline for 20 h . L-NMMA decreased blood flows only to preseptic baseline values . NOS inhibitors may affect blood flows independently of their hemodynamic effects.

Ann Dermatol Venereol, 1996, 123(4), 268 - 70
{Pseudomonas aeruginosa folliculitis after depilation}; De La Cuadra J et al.; INTRODUCTION: Pseudomonas aeruginosa is usually the responsible agent for epidemics of folliculitis acquired in swimming pools and whirlpools . Sporadic cases of Pseudomonas folliculitis after epilation of the legs are well known by dermatologists, but unfrequently reported in the literature . CASE REPORT: We report the case of a 18-year-old female affected of folliculitis of the legs caused by Pseudomonas aeruginosa, after depilation . A meticulous investigation of contaminant sources was performed, and the responsible was the sponge used to wash the legs after depilation . DISCUSSION: Pseudomonas aeruginosa folliculitis after depilation is more frequent than usually reported . A meticulous study of the concomitant source of contamination is essential to avoid recurrent episodes.

Chemotherapy, 1996 Jan-Feb, 42(1), 47 - 56
Meropenem resistance in Pseudomonas aeruginosa; Sumita Y et al.; Two genetically distinct classes of meropenem-low-susceptibility Pseudomonas aeruginosa PAO2152 mutants, which arose spontaneously, were isolated . Two meropenem resistance genes, mpmA and mpmB, were mapped near ilvB/C and proC, respectively, on the P . aeruginosa PAO chromosome . The mpmA was thought to be identical to oprD2 because of the cross-resistance to carbapenems and the association with the loss of the outer membrane protein D2 (OprD2) . The mpmB mutation conferred a 4-fold increase in resistance to meropenem, and cross-resistance to various types of antimicrobial agents, e.g . carbenicillin, norfloxacin and chloramphenicol . However, the mpmB mutant was susceptible to imipenem . This mutant still possessed OprD2 and showed increased expression of a 48-kD outer membrane protein, although its profiles of beta-lactamase activity and affinities of penicillin-binding proteins for beta-lactams were indistinguishable from those of the parent strain . The resistance gene mpmB was considered to be an allele of nalB (or cfxB or oprK) from the results of the transductional analysis . The mutation frequency of mpmA:mpmB was in the ratio of 4:1 . The same results were obtained in another clinically isolated P . aeruginosa strain . Meropenem resistance caused by both mpmA and mpmB mutations seemed to be due to the reduction in permeability of antibiotics through the outer membrane . These findings suggest a new pathway for the translocation of meropenem other than that mediated by OprD2 across the outer membrane . Thus, meropenem showed about 4- to 8-fold higher activity than imipenem against OprD2-deficient P . aeruginosa.

J Clin Microbiol, 1996 Jan, 34(1), 202 - 4
Comparison of ribotyping and genome fingerprinting of Pseudomonas aeruginosa isolates from cystic fibrosis patients; Bennekov T et al.; Forty Pseudomonas aeruginosa strains, previously characterized by pulsed-field gel electrophoresis, were ribotyped with EcoRI, BamHI, ClaI, and PvuII . Ribotyping with PvuII proved to be as discriminatory as pulsed-field gel electrophoresis with XbaI or DraI while EcoRI and BamHI were not . ClaI contributed further ribotypes, some of which might be due to a transposable element.

Jpn J Ophthalmol, 1996, 40(1), 123 - 6
Pharmacokinetics of topically applied ciprofloxacin in rabbit tears; Green LC et al.; Fluoroquinolones provide an important single antibiotic therapy for bacterial keratitis caused by Staphylococcus aureus and numerous gram-negative bacteria, including Pseudomonas aeruginosa . The pharmacokinetics of three ocular fluoroquinolones, norfloxacin (CHIBOXIN, Merck, Sharp & Dohme), ciprofloxacin (CILOXAN, Alcon Laboratories), and ofloxacin (OCUFLOX, Allergan Pharmaceuticals), have been studied in the human eye and in both the normal rabbit eye and rabbit models of keratitis . However, the pharmacokinetics of ciprofloxacin have not been previously studied in the tear film of rabbits . This study was done to determine the pharmacokinetics of topical ciprofloxacin in the rabbit tear film . Two drops of CILOXAN were applied to the eyes of normal rabbits . Tear samples were collected at 5, 10 and 30 minutes, and 1, 2, 4 and 6 hours after topical drug application . Tear samples were analyzed for ciprofloxacin concentrations by HPLC . Ciprofloxacin concentrations reached a peak at 5 minutes, then declined in a manner similar to that reported for norfloxacin and ofloxacin . The ciprofloxacin concentrations in tears were substantially higher throughout the length of the study than the MIC90 for most ocular pathogens including Staphylococcus aureus and Pseudomonas aeruginosa.

QJM, 1996 Jan, 89(1), 71 - 6
Bacterial meningitis in patients with nasopharyngeal carcinoma; Tang LM et al.; Bacterial meningitis was found in 12 patients with nasopharyngeal carcinoma, accounting for 0.65% of the 1850 patients with the tumour diagnosed between 1981 and 1994 in our hospital . In 11 patients, the time-lag between diagnosis of cancer and the appearance of infection ranged from 9 months to 11 years (mean 57 months) whereas in one patient it was only 5 days . Three patients developed mixed bacterial meningitis . Cerebrospinal fluid culture for bacteria was positive in six patients . Three patients (25%) were bacteraemic . Gram-negative bacilli, especially Pseudomonas aeruginosa, were the most common pathogens . Age, sex and histopathology were not risk factors for infection . Conditions predisposing to meningitis included intracranial invasion of the tumor, neutropenia, otitis media, and neurosurgical procedures . All but two patients had intracranial tumour invasion and erosion of the base of the skull . Local spread of micro-organism to the meninges was more important than haematogenous spread . The overall mortality in our patients was 66.7%, much higher than in patients without cancer.

Bioorg Med Chem, 1996 Jan, 4(1), 43 - 8
Synthesis and in vitro antibacterial activity of spermidine-based mixed catechol- and hydroxamate-containing siderophore--vancomycin conjugates; Ghosh M et al.; The first antibiotic conjugates of vancomycin (1) and siderophore analogues containing spermidine-based catechol ligands (conjugate 11) as well as mixed catechol and hydroxamate ligands (conjugate 13) are described . The design of the conjugates was based on the earlier observation that conjugation of siderophore components to beta-lactam antibiotics induced active iron transport-mediated drug delivery . The novel conjugates (11 and 13) were synthesized by selective acylation of the primary amino group of 1 . Preliminary biological studies indicated that siderophore modified vancomycins lost some activity (4- to 16-fold) against Gram-positive bacteria relative to vancomycin itself, and were generally similar to vancomycin in activity against Gram-negative bacteria under iron-sufficient conditions . However, under iron-depleted conditions which mimic human serum, conjugate 11 displayed enhanced antibacterial activity against an antibiotic hypersensitive strain of Pseudomonas aeruginosa.

Schweiz Med Wochenschr Suppl, 1996, 76, 49S - 53S
{The role of aminoglycosides in HIV-infected patients}; Opravil M; The frequency of serious infections due to Pseudomonas aeruginosa is increasing among patients with advanced HIV infection; most of the cases are community-acquired . Early diagnosis and adequate treatment--usually with the combination of an anti-pseudomonas beta-lactam antibiotic and an aminoglycoside--have a crucial bearing on prognosis . The good in vitro activity of aminoglycosides against mycobacteria contrasts with the need for intravenous administration and toxicity . In patients with Mycobacterium avium complex infection, amikacin should be given only in the event of difficulty with an oral regimen and only on a temporary basis . Similar rules apply to the treatment of multiresistant tuberculosis with streptomycin or amikacin . Paromomycin is not absorbed by the gastrointestinal tract when taken orally, constitutes the treatment of choice against cryptosporidiosis and serves as an alternative against Entamoeba histolytica and Giardia lamblia . Topical treatment with paromomycin ointment can be used in cutaneous leishmaniasis.

Rev Mal Respir, 1996, 13(1), 55 - 60
{Pulmonary deposition of colistin aerosols in cystic fibrosis . Comparison of an ultrasonic nebulizer and a pneumatic nebulizer}; Gagnadoux F et al.; The objective of this study was to quantify the deposition in the lung of a Colistine aerosol generated using a pneumatic nebuliser (Pari LL(R) equipped with a Pari Master, Pari, Germany) and to compare this with the results obtained with an ultrasonic nebuliser (DP100, DP Medical, France) in four subjects suffering from cystic fibrosis being colonised with Pseudomonas aeruginosa . To quantify the pulmonary deposition of the aerosols we have used an indirect isotopic method which consists in assimilating the kinetics of the molecules studied with a serum albumin tagged with Technetium 99m (Tc99mm) and added to a preparation of Colistine . We have previously verified that the addition of a radioactive tracer does not change the normal distribution or dynamics of the medication within the aerosol and the radioactive counter linked to the tracer reflects the mass of the medicament . The pulmonary deposition was expressed as a percentage of the nebuliser dose . A regional analysis of the deposition (central, peripheral, superior and inferior) was carried out and in central deposition compared to the periphery (C/P) and superior compared to inferior (S/I) were calculated . With the DP100 nebuliser the pulmonary deposition of the aerosol was very reproducible from one patient to another, varying only between 9.5 to 14 percent of the nebuliser dose . With the Pari LL the fraction deposited varied more from one patient to another from 5.6 to 27% of the nebuliser dose . In three of four patients, the pulmonary deposition was superior or equal to that obtained with the ultrasonic nebuliser . The patients whose pulmonary deposition was inferior, using the pneumatic nebuliser, was the youngest in the group and co-ordinately poorly the triggering of the nebuliser with the beginning of inspiration . With the two nebulisers, the pulmonary deposition of Colisitine was very heterogeneous throughout the pulmonary parenchyma . The mean of the ratio C/P and S/I obtained in all four patients was identical (1.35 an 0.86 respectively), indicating a deposition of the aerosol which was predominantly central and inferior but was distributed equally in the peripheral parts of the lung . Pneumatic nebulisers offer a reliable alternative notably for domiciliary treatment for Colistine aerosols in patients suffering from cystic fibrosis . In younger patients who have not yet acquired good motor co-ordination, nebulisers which function continuously or are triggered by inspiration seem to be the preferred choice.

Nephrol Dial Transplant, 1996 Jan, 11(1), 101 - 8
Induction of interleukin-1 and interleukin-1 receptor antagonist during contaminated in-vitro dialysis with whole blood; Schindler R et al.; BACKGROUND . Previous studies on the permeability of cellulosic and synthetic dialysers for bacterial-derived cytokine-inducing substances gave conflicting results . We tried to study this issue as close to the in-vivo situation as possible . METHODS . An in-vitro dialysis circuit with whole human blood present in the blood compartment of cuprophane (Cup), polysulphone (PS), and polyamide (PA) dialysers was employed; sterile filtrates derived from Pseudomonas aeruginosa cultures were added to the dialysate . We studied the induction of interleukin-1 beta (IL-1 beta) by plasma samples taken from the blood compartment as well as the induction of IL-1 beta and interleukin-1 receptor antagonist (IL-1Ra) in mononuclear cells separated from whole blood after circulation by radioimmunoassay and polymerase chain reaction . RESULTS . Plasma samples from the blood side of all dialysers induced IL-1 beta from non-circulated mononuclear cells after addition of pseudomonas filtrates to the dialysate; the maximal amount of IL-1 beta induced by samples from the blood compartment was 4.8 +/- 1.2 ng/ml for Cup, 1.9 +/- 0.5 ng/ml for PS, and 2.0 +/- 0.6 ng/ml for PA . Mononuclear cells separated after contaminated dialysis will all types of dialysers expressed increased mRNA levels for IL-1 beta and IL-1Ra . Production of IL-1Ra by cells separated after contaminated dialysis was determined after Cup and PS dialysis; there was increased production of IL-1Ra by these cells (Cup, 10.3 +/- 4.2; PS, 7.3 +/- 2.5 ng/ml) compared to cells separated after sterile dialysis (Cup, 5.6 +/- 2.1, P < 0.05; PS, 4.5 +/- 1.1 ng/ml, n.s.) or from non-circulated blood (Cup experiments, 4.7 +/- 1.5, P < 0.05; PS experiments, 4.1 +/- 1.2 ng/ml, n.s.) . CONCLUSIONS . These data suggest penetration of cytokine-inducing substances through both cellulosic and synthetic dialysers . Differences between dialysers may exist regarding extent and time course of penetration . The detection of cytokine mRNA as well as the measurement of IL-1Ra synthesis is a more sensitive marker for the transfer of cytokine-inducing substances through dialyser membranes than the measurement of IL-1 beta protein synthesis.

Eur J Clin Microbiol Infect Dis, 1996 Jan, 15(1), 82 - 5
Relationship between outer membrane protein profiles and resistance to ceftazidime, imipenem, and ciprofloxacin in Pseudomonas aeruginosa isolates from bacteremic patients; Gimeno C et al.; Outer membrane protein (OMP) profiles of 122 Pseudomonas aeruginosa isolates recovered from the blood of bacteremic patients were analyzed to relate alterations in the expression of OMPs with porin activity to resistance to imipenem, ceftazidime, and ciprofloxacin . Imipenem-resistant isolates lacked or expressed reduced amounts of porin OprD . In contrast, alterations of OMP profiles were absent in most ceftazidime-resistant isolates . Six of 12 ciprofloxacin-resistant isolates had normal OMP profiles . The remaining isolates showed alterations in the expression of either OprC, OprF, or OprD . In addition, imipenem- and ceftazidime-resistant isolates displayed a beta-lactamase activity compatible with that of a group 1 chromosomal cephalosporinase.

FEMS Microbiol Lett, 1996 Jan 1, 135(1), 123 - 9
A mutant of Pseudomonas aeruginosa that lacks c-type cytochromes has a functional cyanide-insensitive oxidase; Ray A et al.; Using transposon mutagenesis and screening for the loss of the ability to oxidise the artificial electron donor N,N,N',N'-tetramethyl-p-phenylenediamine, we have isolated a mutant of Pseudomonas aeruginosa that lacks all c-type cytochromes . This mutant is unable to grow anaerobically with nitrate as a terminal electron acceptor . Analysis of its respiratory function indicates that the mutant has lost its cytochrome c oxidase-terminated respiratory pathway but the cyanide-insensitive oxidase-terminated branch remains functional . Complementation of the mutant by in vivo cloning led to recovery of the wild-type characteristics . These data are consistent with the idea that the cyanide-insensitive respiratory pathway does not contain haem c and that the pathway's terminal oxidase is a quinol oxidase.

J Surg Res, 1996 Jan, 60(1), 186 - 92
Pulmonary artery endothelial cell function in swine pseudomonas sepsis; Kadletz M et al.; A substantial increase in pulmonary vascular resistance is associated with sepsis and its sequelae (sepsis syndrome and septic shock) . It is postulated that increased resistance may result from sepsis-induced endothelial cell injury or altered vasoreactivity secondary to pulmonary hypertension . We, therefore, tested the hypothesis that sepsis causes endothelial cell injury and that increased pulmonary pressure alters vascular reactivity . Young swine (15-25 kg) were anesthetized and ventilated . Septic animals received a 1-hr infusion of live Pseudomonas aeruginosa (n = 11), and the control cohort received 0.9% NaCl (n = 7) . All animals were studied for 300 min following the infusion . Postmortem branches of peripheral pulmonary arteries were prepared and tested in a vessel myograph . Ring segments were set to 90% of the circumference the vessels would have at pressures of 20, 30, 40, or 50 mmHg (L90), corresponding to varying pulmonary pressures observed in sepsis . A high dose of potassium was used to obtain maximum possible contraction . Prostaglandin was used to precontract the vessels before testing endothelial cell responses to acetylcholine or bradykinin . Sodium nitroprusside was added at the end of each experiment to obtain maximum possible smooth muscle relaxation . No differences in contraction or relaxation were observed when vessels were set to different pressures (i.e., 20 vs 50 mmHg) . Maximum possible contraction to KCl was significantly decreased after 300 min of sepsis compared to control . No differences between groups were found in contractility to prostaglandin . Bradykinin-induced EDRF/NO production, mediated by BK2 receptors, was not altered in Pseudomonas sepsis (97-98% of total relaxation control and 91-95% septic cohort) . Response to acetylcholine was significantly decreased after sepsis (89-95% of total relaxation control and 51-61% of septic cohort relaxation) . Decreased response to acetylcholine could not be attributed to decreased smooth muscle sensitivity to nitric oxide because the response to bradykinin plus sodium nitroprusside was not altered following sepsis . Vessel reactivity was not altered by increasing pressure settings reflective of changing pulmonary pressure in vivo . These results strongly suggest a sepsis-induced alteration in pulmonary artery endothelial cell receptor sensitivity to acetylcholine, independent of changing pulmonary arterial pressures . This is the first time this decrease has been shown in pseudomonas sepsis.

Microbiology, 1996 Jan, 142 ( Pt 1), 79 - 86
Physical mapping of 32 genetic markers on the Pseudomonas aeruginosa PAO1 chromosome; Liao X et al.; The Pseudomonas aeruginosa chromosome was fractionated with the enzymes SpeI and DpnI, and genomic fragments were separated by PFGE and used for mapping a collection of 40 genes . This permitted the localization of 8 genes previously mapped and of 32 genes which had not been mapped . We showed that a careful search of databases and identification of sequences that were homologous to known genes could be used to design and synthesize DNA probes for the mapping of P . aeruginosa homologues by Southern hybridization with genomic fragments, resulting in definition of the locations of the aro-2, dapB, envA, mexA, groEL, oprH, oprM, oprP, ponA, rpoB and rpoH genetic markers . In addition, a combination of distinct DNA sources were utilized as radioactively labelled probes, including specific restriction fragments of the cloned genes (glpD, opdE, oprH, oprO, oprP, phoS), DNA fragments prepared by PCR, and single-stranded DNA prepared from phagemid libraries that had been randomly sequenced . We used a PCR approach to clone fragments of the putative yhhF, sucC, sucD, cypH, pbpB, murE, pbpC, soxR, ftsA, ftsZ and envA genes . Random sequencing of P . aeruginosa DNA from phagemid libraries and database searching permitted the cloning of sequences from the acoA, catR, hemD, pheS, proS, oprD, pyo and rpsB gene homologues . The described genomic methods permit the rapid mapping of the P . aeruginosa genome without linkage analysis.

Infect Immun, 1996 Jan, 64(1), 37 - 43
Contribution of specific Pseudomonas aeruginosa virulence factors to pathogenesis of pneumonia in a neonatal mouse model of infection; Tang HB et al.; We sought to identify which Pseudomonas aeruginosa products are involved initiating respiratory tract infection . Defined mutants derived from strain PAO i.e., PAOR1 (lasR),PAO-pmm (algC) (an LPS mutant), and AK1152 (which is Fla- and lacks functional pili), were significantly less virulent than PAO1 in a BALBc/ByJ neonatal mouse model of infection as measured by their abilities to cause acute pneumonia, bacteremia, and death . All three mutants were also less adherent to epithelial cells in an in vitro binding assay . PAOR1 and AK1152 were less able to elicit epithelial production of interleukin-8 than PAO1 . LasR was found to be required for the optimal expression of neuraminidase under conditions of increased osmolarity, as might be present in certain pathological conditions . PAO-exsA::omega,, which lacks exoenzyme S expression, was fully virulent, causing at least as much pathology as PAO1 . The expression of several P . aeruginosa virulence factors appears to be required to establish pulmonary infection in the neonatal mouse.

Infect Immun, 1996 Jan, 64(1), 182 - 8
Protease cleavage of iron-transferrin augments pyocyanin-mediated endothelial cell injury via promotion of hydroxyl radical formation; Miller RA et al.; Although a number of bacterium- and host-derived factors have been suggested to contribute to the pathogenesis of Pseudomonas aeruginosa-associated tissue injury, the mechanism remains unclear . We have previously shown that protease modification of iron (Fe)-transferrin generates new iron chelates capable of catalyzing hydroxyl radical (.OH) formation from superoxide and hydrogen peroxide . The latter two oxidants are generated during redox cycling of another P . aeruginosa secretory product, pyocyanin . The lung is a major site of P . aeruginosa infection, with damage to local endothelial cells contributing to the pathogenesis of such infections . Endothelial cells are highly susceptible to oxidant-mediated injury . Therefore, we examined whether pseudomonas elastase-cleaved Fe-transferrin and pyocyanin synergistically enhance pulmonary artery endothelial cell injury via .OH formation . By measuring 51Cr release from cultured endothelial cell monolayers, pseudomonas elastase-cleaved Fe-transferrin significantly augmented cell injury resulting from cellular exposure to sublethal concentrations of pyocyanin . This enhancement in injury was not protease specific, as similar results were obtained with pyocyanin in combination with trypsin- or porcine pancreatic elastase-cleaved Fe-transferrin . The association of iron with the transferrin appeared to be necessary in this process . Supporting the involvement of .OH generation via the Haber-Weiss reaction in augmenting cell injury, catalase, dimethyl thiourea, superoxide dismutase, deferoxamine, and dimethyl sulfoxide significantly inhibited cell injury resulting from exposure to pyocyanin and protease-cleaved Fe-transferrin . Furthermore, spin trapping demonstrated the production of .OH in this cellular system . We conclude that .OH formation resulting from the interaction of protease-cleaved Fe-transferrin and endothelial cell redox cycling of pyocyanin may contribute to P . aeruginosa-associated tissue injury via endothelial cell injury.

J Bacteriol, 1996 Jan, 178(2), 511 - 23
Two distinct loci affecting conversion to mucoidy in Pseudomonas aeruginosa in cystic fibrosis encode homologs of the serine protease HtrA; Boucher JC et al.; Conversion to a mucoid, exopolysaccharide alginate-overproducing phenotype in Pseudomonas aeruginosa is associated with chronic respiratory infections in cystic fibrosis . Mucoidy is caused by muc mutations that derepress the alternative sigma factor AlgU, which in turn activates alginate biosynthetic and ancillary regulatory genes . Here we report the molecular characterization of two newly identified genes, algW and mucD, that affect expression of mucoidy . The algW gene, mapping at 69 min, was isolated on the basis of its ability to suppress mucoidy and reduce transcription of the alginate biosynthetic gene algD . The predicted primary structure of AlgW displayed similarity to HtrA (DegP), a serine protease involved in proteolysis of abnormal proteins and required for resistance to oxidative and heat stress in enteric bacteria . Inactivation of algW on the chromosome of the wild-type nonmucoid strain PAO1 caused increased sensitivity to heat, H2O2, and paraquat, a redox cycling compound inducing intracellular levels of superoxide . This mutation also permitted significant induction of alginate production in the presence of subinhibitory concentrations of paraquat . Two new genes, mucC and mucD, were identified immediately downstream of the previously characterized portion (algU mucA mucB) of the gene cluster at 67.5 min encoding the alternative sigma factor AlgU and its regulators . Interestingly, the predicted gene product of mucD also showed similarities to HtrA . Inactivation of mucD on the PAO1 chromosome resulted in conversion to the mucoid phenotype . The mutation in mucD also caused increased sensitivity to H2O2 and heat killing . However, in contrast to algW mutants, no increase in susceptibility to paraquat was observed in mucD mutants . These findings indicate that algW and mucD play partially overlapping but distinct roles in P . aeruginosa resistance to reactive oxygen intermediates and heat . In addition, since mutations in mucD and algW cause conversion to mucoidy or lower the threshold for its induction by reactive oxygen intermediates, these factors may repress alginate synthesis either directly by acting on AlgU or its regulators or indirectly by removing physiological signals that may activate this stress response system.

J Bacteriol, 1996 Jan, 178(2), 490 - 5
Cloning and characterization of a gene (msdA) encoding methylmalonic acid semialdehyde dehydrogenase from Streptomyces coelicolor; Zhang YX et al.; A homolog of the mmsA gene of Pseudomonas aeruginosa, which encodes methylmalonic acid semialdehyde dehydrogenase (MSDH) and is involved in valine catabolism in pseudomonads and mammals, was cloned and sequenced from Streptomyces coelicolor . Of the two open reading frames (ORFs) found, which are convergently transcribed and separated by a 62-nucleotide noncoding region, the deduced amino acid sequence of the msdA ORF (homologous to mmsA) is similar to a variety of prokaryotic and eukaryotic aldehyde dehydrogenases that utilize NAD+, particularly to the MmsA protein from P . aeruginosa . No significant similarity was found between the deduced product of ORF1 and known proteins in the databases . An S . coelicolor msdA mutant, constructed by insertion of a hygromycin resistance gene (hyg) into the msdA coding region, lost the MSDH activity and the ability to grow in a minimal medium with valine or isobutyrate as the sole carbon source but grew on propionate . The msdA::hyg mutation was complemented by introduction of the msdA gene on a plasmid . When the S . coelicolor msdA gene was overexpressed in Escherichia coli under the control of the T7 promoter, a protein of 51-kDa, corresponding to the approximate mass of the predicted S . coelicolor msdA product (52.6 kDa), and specific MSDH activity were detected . These results strongly suggest that msdA indeed encodes the MSDH that is involved in valine catabolism in S . coelicolor.

J Bacteriol, 1996 Jan, 178(2), 410 - 7
Characterization of genes required for pilus expression in Pseudomonas syringae pathovar phaseolicola; Roine E et al.; Nonpiliated, phage phi 6-resistant mutants of Pseudomonas syringae pv . phaseolicola were generated by Tn5 transposon mutagenesis . A P . syringae pv . phaseolicola LR700 cosmid library was screened with Tn5-containing EcoRI fragments cloned from nonpiliated mutants . The cosmid clone pVK253 complemented the nonpiliated mutant strain HB2.5 . A 3.8-kb sequenced region spanning the Tn5 insertion site contained four open reading frames . The transposon-inactivated gene, designated pilP, is 525 bp long, potentially encoding a 19.1-kDa protein precursor that contains a typical membrane lipoprotein leader sequence . Generation of single mutations in each of the three remaining complete open reading frames by marker exchange also resulted in a nonpiliated phenotype . Expression of this gene region by the T7 expression system in Escherichia coli resulted in four polypeptides of approximately 39, 26, 23, and 18 kDa, in agreement with the sizes of the open reading frames . The three genes upstream of pilP were designated pilM (39 kDa), pilN (23 kDa), and pilO (26 kDa) . The processing of the PilP precursor into its mature form was shown to be inhibited by globomycin, a specific inhibitor of signal peptidase II . The gene region identified shows a high degree of homology to a gene region reported to be required for Pseudomonas aeruginosa type IV pilus production.

J Bacteriol, 1996 Jan, 178(1), 85 - 93
Comparative genome mapping of Pseudomonas aeruginosa PAO with P . aeruginosa C, which belongs to a major clone in cystic fibrosis patients and aquatic habitats; Schmidt KD et al.; A physical and genetic map was constructed for Pseudomonas aeruginosa C . Mainly, two-dimensional methods were used to place 47 SpeI, 8 PacI, 5 SwaI, and 4 I-CeuI sites onto the 6.5-Mb circular chromosome . A total of 21 genes, including the rrn operons and the origin of replication, were located on the physical map . Comparison of the physical and genetic map of strain C with that of the almost 600-kb-smaller genome of P . aeruginosa reference strain PAO revealed conservation of gene order between the two strains . A large-scale mosaic structure which was due to insertions of blocks of new genetic elements which had sizes of 23 to 155 kb and contained new SpeI sites was detected in the strain C chromosome . Most of these insertions were concentrated in three locations: two are congruent with the ends of the region rich in biosynthetic genes, and the third is located in the proposed region of the replication terminus . In addition, three insertions were scattered in the region rich in biosynthetic genes . The arrangement of the rrn operons around the origin of replication was conserved in C, PAO, and nine other examined independent strains.

J Bacteriol, 1996 Jan, 178(1), 46 - 53
Identification of a novel gene, pilZ, essential for type 4 fimbrial biogenesis in Pseudomonas aeruginosa; Alm RA et al.; The opportunistic pathogen Pseudomonas aeruginosa produces type 4 fimbriae which promote adhesion to epithelial cells and are associated with a form of surface translocation called twitching motility . We have used transposon mutagenesis to identify loci required for fimbrial assembly or function by screening for mutants that lack the spreading colony morphology characteristic of twitching motility . A subset of these mutants is resistant to fimbria-specific phage . One of these mutants (R270) was found to contain a transposon insertion in a new gene, termed pilZ, which is located on chromosomal SpeI fragment I at about 40 min on the P . aeruginosa map, a position remote from other loci involved in fimbrial biogenesis . pilZ appears to be linked to and possibly forms an operon with a gene, holB*, which is homologous to the gene encoding the delta' subunit of Escherichia coli DNA polymerase III . The product of the pilZ gene is a protein of 118 amino acids (predicted molecular weight, 12,895) which probably has a cytoplasmic location . PilZ appears to be a new class of protein which has not hitherto been represented in the sequence databases, and its function is unknown . Complementation studies indicate that pilZ is able to restore the expression of fimbriae on the surface of P . aeruginosa, as well as twitching motility and sensitivity to fimbria-specific phage when provided in trans to the R270 mutant.

J Bacteriol, 1996 Jan, 178(1), 103 - 10
Construction and characterization of pyocin-colicin chimeric proteins; Kageyama M et al.; Chimeric proteins were constructed from pyocin S1 or S2 and colicin E3 or E2, and their characteristics were investigated with special reference to the domain structure . The nuclease domains were interchangeable between two bacteriocins so that a new kind of pyocin, with RNase activity, was created . A bacteriocin which can kill both Pseudomonas aeruginosa and Escherichia coli was also constructed . Investigations with various chimeric proteins indicate that the translocation domain as well as the receptor-binding domain is species specific . Inhibition of lipid synthesis, which is characteristic of pyocins, was also observed with chimeric pyocins carrying the DNase domain of colicin E2 but not with those carrying the RNase domain of E3 . Thus, the DNase domain is responsible for the inhibition of lipid synthesis.

Invest Ophthalmol Vis Sci, 1996 Jan, 37(1), 20 - 8
Inhibition of pseudomonal ulceration in rabbit corneas by a synthetic matrix metalloproteinase inhibitor; Barletta JP et al.; PURPOSE . To evaluate the effect of the synthetic matrix metalloproteinase inhibitor, Galardin, on proteases produced by Pseudomonas aeruginosa (PA) and on a rabbit model of Pseudomonas keratitis . METHODS . Protease activities of culture broths from Pseudomonas strains PA-28 and W-186 were characterized in vitro by gelatin zymography and by digestion of Azocasein in the presence and absence of Galardin and the serine protease inhibitor, aprotinin . In a noninfectious in vivo experiment, sterile PA culture broth from W-186 was injected intrastromally into rabbit corneas that were treated topically with Galardin or vehicle, then evaluated clinically and histologically . In an infectious in vivo experiment, rabbit corneas were injected with washed PA-28, then treated topically with Galardin or vehicle and clinically scored . RESULTS . Gelatin zymography of culture broth from W-186 and PA-28 detected two proteases that were both inhibited by Galardin . Galardin reduced the digestion of Azocasein by both PA culture broths by 99%, whereas aprotinin did not significantly reduce the protease activity of PA-28 conditioned broth . Intrastromal injection of sterile W-186 culture broth caused rapid corneal destruction that was prevented by topical treatment with Galardin . Intrastromal injection of washed PA-28 bacteria resulted in progressive corneal melting that was significantly (P < 0.005) delayed, but ultimately not prevented, by topical treatment with Galardin . CONCLUSIONS . Pseudomonal protease activity in culture broth consisted predominantly of metalloproteinases and were effectively inhibited by Galardin in vitro . Topical treatment with Galardin prevented destruction of rabbit corneas by bacterial products present in culture broth, and it delayed corneal destruction after injection of PA bacteria . Galardin may be a useful adjuvant when corneal destruction proceeds despite prompt antibiotic treatment.

Am J Respir Crit Care Med, 1996 Jan, 153(1), 325 - 30
Effect of sodium nitroprusside and diethylcarbamazine on hypoxic pulmonary vasoconstriction and regional distribution of pulmonary blood flow in experimental pneumonia; Light RB; The interaction between the effects of indomethacin and sodium nitroprusside or diethylcarbamazine infusion on the efficacy of hypoxic pulmonary vasoconstriction (HPV) and regional distribution of lung blood flow was studied in 15 pentobarbital-anesthetized dogs with acute pneumonia caused by Pseudomonas aeruginosa . After induction of pneumonia central hemodynamics, gas exchange, and regional distribution of lung blood flow (radionuclide-labeled microsphere method) were measured during ventilation of both lungs with oxygen and again with one lung ventilated with nitrogen . The dogs were then randomly assigned to one of three treatment groups: Group I (n = 5) received indomethacin alone (2 mg/kg); Group I-D received indomethacin and diethylcarbamazine (50 mg/kg over 20 min followed by 1 mg/kg/min for the rest of the experiment); Group I-N (n = 5) received indomethacin with sodium nitroprusside to achieve a 20- to 30-mm Hg reduction in mean blood pressure . All measurements were then repeated during both oxygen ventilation and one-lung nitrogen ventilation . In all three groups there was no effect of nitrogen inhalation on distribution of lung blood flow prior to drug treatment, indicating absence of HPV . After treatment, in Group I, perfusion of the pneumonic lung fell from 0.27 +/- 0.08 to 0.10 +/- 0.03 (p < 0.05) of total lung blood flow, and nitrogen ventilation of the left lung reduced perfusion to that region from 0.23 +/- 0.02 to 0.13 +/- 0.02 (p < 0.05), indicating restoration of HPV . In Groups I-D and I-N, HPV was persistently absent or markedly attenuated after treatment, but the percentage of the cardiac output perfusing the pneumonia region fell by an amount similar to that in Group I (0.26 +/- 0.07 to 0.11 +/- 0.04 in Group I-D and 0.35 +/- 0.03 to 0.21 +/- 0.06 in Group I-N, both p < 0.05) . Because these two chemically unrelated pulmonary vasodilators effectively blocked HPV restoration but had no effect on vasoconstriction in the pneumonia region after indomethacin, it is concluded that regional lung blood flow redistribution in pneumonia is mediated by a mechanism other than HPV.

Gene, 1995 Dec 29, 167(1-2), 87 - 91
Sequencing and characterization of the downstream region of the genes encoding nitrite reductase and cytochrome c-551 (nirSM) from Pseudomonas aeruginosa: identification of the gene necessary for biosynthesis of heme d1; Kawasaki S et al.; The nirC and nirF genes were identified downstream from nirSM, the structural genes encoding nitrite reductase (NIR) and cytochrome c-551 from Pseudomonas aeruginosa (Pa) . The nirC gene encodes a probable c-type cytochrome with a signal sequence for membrane translocation . The nirF gene codes for a protein of 392 amino acids . A nirF mutant of Pa, constructed by marker exchange mutagenesis, synthesized an inactive NIR protein whose activity was restored by adding purified heme d1 . The mutant strain produced an active NIR, when it was transformed by a broad-host-range plasmid carrying nirF . These results showed that the product of nirF was essential for the biosynthesis of heme d1 in Pa.

Gene, 1995 Dec 29, 167(1-2), 81 - 6
Cloning and characterization of the gene (rfc) encoding O-antigen polymerase of Pseudomonas aeruginosa PAO1; Coyne MJ Jr et al.; The lipopolysaccharide (LPS) O-antigen polymerase is the product of the rfc gene . Loss of O-antigen polymerase activity due to mutation in rfc gives rise to a characteristic LPS phenotype known as core-plus-one or semi-rough, wherein the LPS core is capped with a single oligosaccharide unit . Pseudomonas aeruginosa (Pa) AK1401, a derivative of strain PAO1 (serogroup O5), expresses a semi-rough LPS; this mutant phenotype was complemented by a 2.2-kb NsiI-SacI fragment of Pa PAO1 DNA . Sequence analysis of this fragment revealed a 1317-bp open reading frame (ORF) potentially encoding a 438-amino-acid (aa) protein of 48,849 Da . This DNA sequence and the inferred aa sequence contain many of the features of other O-antigen polymerases, including an aberrantly low G + C content (particularly apparent in the high-G + C background of Pa), an unusual codon usage pattern, and a hydrophobicity profile indicative of a membrane protein . A 345-bp fragment internal to the ORF hybridized to genomic DNA from two of ten Pa serogroup strains examined by Southern blot; these two strains express O antigens structurally related to that of strain PAO1.

Biochim Biophys Acta, 1995 Dec 27, 1264(3), 249 - 53
Characterization of the Pseudomonas aeruginosa transposable bacteriophage D3112 A and B genes; Ulycznyj PI et al.; The left end DNA of Mu-like transposable bacteriophage D3112 was sequenced from bp 2521 to bp 5483 . Two large open reading frames were identified: ORF A (bp 2539-4611) and ORF B (bp 4626-5378) . ORF A can encode a 690 amino acid, 78 kDa protein which is 44.4% similar to Mu transposase and ORF B can encode a 250 amino acid, 27 kDa protein, which is 46.4% similar to, though 62 amino acids shorter than, the Mu B protein . The cloned D3112 A gene exhibited activity on a mini-D3112-containing plasmid in Pseudomonas aeruginosa.

Biochemistry, 1995 Dec 19, 34(50), 16255 - 68
Comparison of NMR solution structures of the receptor binding domains of Pseudomonas aeruginosa pili strains PAO, KB7, and PAK: implications for receptor binding and synthetic vaccine design; Campbell AP et al.; The solution structures of peptide antigens from the receptor binding domains of Pseudomonas aeruginosa strains PAO and KB7 have been determined using two-dimensional 1H NMR techniques . Ensembles of solution conformations for the trans forms of these 17-residue disulfide-bridged peptides have been generated using a simulated annealing procedure in conjunction with distance and torsion angle restraints derived from NMR data . Comparison of the NMR-derived solution structures of the PAO and KB7 peptides, with that previously determined (McInnes et al., 1993) and herein refined for the PAK peptide reveals a common structural motif . All three peptide structures contain a type I beta-turn in the conserved sequence Asp134-X-X-Phe137 and a type II beta-turn in the conserved sequence Pro139-X-Gly-Cys142 . However, the overall folds of the three peptides differ as well as the disposition of the side chains comprising the hydrophobic pockets . The similarities and differences between the structures of the three strains which bind to a common cell surface receptor are discussed in light of their contributions to synthetic vaccine design.

FEBS Lett, 1995 Dec 18, 377(2), 145 - 9
A reinvestigation of the covalent structure of Pseudomonas aeruginosa cytochrome c peroxidase; Samyn B et al.; The amino acid sequence of cytochrome c peroxidase from Pseudomonas aeruginosa has been determined using classical chemical degradation techniques combined with accurate mass analysis of all the generated peptides . The sequence obtained is composed of 346 amino acids and confirms the recently published cDNA-derived sequence except at one position {Ridout et al . (1995) FEBS Lett . 365, 152-154} . Based on this sequence, we propose a new model for the binding of the peroxide and the cytochrome electron donor to CCP which is in essence the reverse of the one proposed by Ellfolk et al.

Presse Med, 1995 Dec 16-23, 24(39), 1882 - 7
{Cystic fibrosis in adults}; Durieu I et al.; OBJECTIVES: At least half cystic fibrosis patients now reach adulthood . METHODS: We report a population of 61 patients above 18 years of age with the clinical pictures at time of diagnosis and the present clinical status . RESULTS: Thirty-five males and 26 females are aged from 18 to 47 years . Mean age at time of diagnosis was 5 years and 5 months, under 10 years in 80% of patients and above 15 years in 9 patients . Diagnosis was suspected because of pulmonary (2/3) or digestive (1/3) symptoms, insufficient height and weight (1/3) or past family history of cystic fibrosis (1/3) . 37% of patients are homozygotes for delta F508 mutation . Adult patients had a normal height but half of them a body weight under 90% of expected weight . Recurrent pulmonary infections were observed in 95% of patients and 62% have chronically infected sputum with Pseudomonas aeruginosa . These patients had lower weight and a poorer radiological score than patients without pseudomonas . 25% of all patients had chronic respiratory insufficiency . 75% had pancreatic insufficiency and 6 patients diabetes mellitus . Thirteen patients had biological cholestasis and three a liver cirrhosis with portal hypertension . Four women underwent 6 normal pregnancies; semen analysis in five men revealed aspermia . Seven patients died during the last two years because of respiratory insufficiency (4), in the three months after pulmonary transplantation (2), and because of digestive haemorrhage (1) . CONCLUSION: Treatment included daily bronchial drainage, adapted antibiotic treatment and pancreatic enzyme substitution.

FEMS Microbiol Lett, 1995 Dec 15, 134(2-3), 137 - 41
Isolation and structure of a new integron that includes a streptomycin resistance gene from the R plasmid of Pseudomonas aeruginosa; Kazama H et al.; A new integron, located on the R plasmid of Pseudomonas aeruginosa, was isolated in Japan . This integron was made up of two conserved segments (5'-and 3'-conserved segments) and a single streptomycin resistance gene as a gene cassette . The structure of this integron resembles that of integron InC, the existence of which was postulated by Bissonnette and Roy (J . Bacteriol . 174, 1248-1257, 1992).

Mol Gen Genet, 1995 Dec 15, 249(5), 515 - 25
Toxin A secretion in Pseudomonas aeruginosa: the role of the first 30 amino acids of the mature toxin; McVay CS et al.; Toxin A, one of several virulence factors secreted by the gram-negative bacterium Pseudomonas aeruginosa, is synthesized as a 71 kDa precursor with a typical prokaryotic leader peptide (LP), and is secreted as a 68 kDa mature protein . Evidence from a previous study suggested that a signal required for toxin A secretion in P . aeruginosa may reside within the region defined by the toxin A LP and the first 30 amino acids (aa) of mature toxin A . In the present study, we have used exonuclease Bal31 deletion analysis to examine the specific role of the first 30 aa in toxin A secretion . Four toxA subclones, which encode products containing the toxin A LP and different segments of the 30-residue region fused to a toxin A carboxy-terminal region, were identified . In addition, a gene fusion encoding a hybrid protein consisting of the LP of P . aeruginosa elastase and the final 305 residues of toxin A, was generated . The cellular location of the toxA subclone products in P . aeruginosa was determined by immunoblotting analysis . Toxin A CRMs (cross-reacting material) encoded by different subclones were detected in different fractions of P . aeruginosa including the periplasm and the supernatant . Results from these studies suggest that (1) mature toxin A contains two separate secretion signals one within the N-terminal region and one within the C-terminal region; and (2) the first 30 residues of the mature toxin A form part of the N-terminal secretion signal.

Biochim Biophys Acta, 1995 Dec 12, 1272(3), 185 - 9
Scavenging of neutrophil-derived superoxide anion by 1-hydroxyphenazine, a phenazine derivative associated with chronic Pseudomonas aeruginosa infection: relevance to cystic fibrosis; Muller M; The airways of cystic fibrosis patients colonised by Pseudomonas aeruginosa contain the redox active phenazine derivative, 1-hydroxyphenazine (OHP) . As the presence of reactive oxygen species is of importance to tissue damage in cystic fibrosis, OHP was investigated for its ability to reduce molecular oxygen to superoxide . In the presence of NADPH, OHP reduced cytochrome c in a dose-dependent manner . This effect was not inhibited by superoxide dismutase and demonstrates an electron transport role for OHP . The OHP/NADPH system was unable to reduce molecular oxygen to superoxide as judged by an inability to oxidase epinephrine to adrenochrome . However, using lucigenin-enhanced chemiluminescence to detect superoxide, it was found that pathophysiologically relevant concentrations of OHP (5-25 microM) effectively scavenged superoxide from a xanthine/xanthine oxidase system . Similarly, in the presence of OHP, superoxide availability from contact-activated neutrophils was substantially reduced . It is concluded that OHP is an efficient scavenger of superoxide and that electron transfer from superoxide to OHP represents a major mechanism for reduction of OHP in vivo . Reduced OHP has the potential to alter cellular function by participating in the reduction of iron-containing proteins and in this manner contribute to the pathogenesis of P . aeruginosa infection in cystic fibrosis.

J Hosp Infect, 1995 Dec, 31(4), 261 - 74
Comparative hygienic surveillance of contamination with pseudomonads in a cystic fibrosis ward over a 4-year period; Bosshammer J et al.; In order to study the long-term distribution and population dynamics of Pseudomonas aeruginosa strains in a highly contaminated hospital environment, two 4-week epidemiological studies, with an interval of 4 years, were carried out in the cystic fibrosis (CF) ward of the Paediatric Clinic of the Medical School of Hannover . Out of the 1948 specimens taken, P . aeruginosa was mainly identified in those from moist, inanimate sources (200 isolates) and hospitalized CF patients (168 isolates) . A correlation was established between the frequency with which P . aeruginosa-positive patients came into contact with hospital facilities and the rate of contamination of these facilities . Rooms reserved for colonized patients were more frequently contaminated with P . aeruginosa in contrast to function rooms in the same ward and the outpatient clinic . However, no direct exchange between patients' strains and the inanimate hospital environment was detected . Out of the 11 genotypes of P . aeruginosa found in 1989 and the 13 genotypes found in 1993, four genotypes were present on both occasions . The most predominant clone was found in tap-water, sinks, wash-basins and creams with an incidence of 34 and 68% in the environmental isolates . The strains seemed to have spread into the adjacent control ward during the 4-year interval . Thus, the separation of colonized and non-colonized patients was undermined through the transfer of strains from a highly contaminated environment without additional hygiene precautions.

Mol Microbiol, 1995 Dec, 18(5), 877 - 89
The elastase propeptide functions as an intramolecular chaperone required for elastase activity and secretion in Pseudomonas aeruginosa; McIver KS et al.; Several proteases are secreted by Pseudomonas aeruginosa including elastase, an abundantly secreted neutral zinc-metalloprotease . Elastase (encoded by lasB) is first synthesized with a relatively large propeptide (18 kDa) domain . Here, we present evidence that this propeptide functions as an intramolecular chaperone (IMC) essential for proper maturation of elastase into a hydrolytically active enzyme . An altered elastase allele (lasB6) that encoded an elastase precursor with a precise propeptide deletion was expressed in Escherichia coli, and disrupted cells contained only inactive elastase . However, co-expression of an allele (lasB7) expressing the propeptide as an independent, non-covalently linked protein rescued about one-third of the hydrolytic activity when compared with that obtained with wild-type lasB . Thus, the propeptide was essential for elastase activity and so defined elastase as an IMC-containing protease . We examined the possibility that the propeptide of elastase also plays a role in the localization of the mature protein past the outer bacterial membrane . Expression of lasB6 in P . aeruginosa (lasB delta) in the absence of the propeptide resulted in production of inactive elastase that accumulated within the cell and was not secreted to the culture medium . When lasB7 co-expressed the non-covalently linked propeptide in the same cell with lasB6, efficient secretion was restored and active elastase was then found in the supernatant . Thus, the propeptide was needed for secretion of the mature protein as well as enzymatic activity . This chaperone-like activity of the propeptide appears to involve a direct interaction between the mature and propeptide sequences, and evidence for this was obtained by demonstrating that the non-covalently attached 18 kDa propeptide was co-precipitated with elastase using elastase antibodies . These results are consistent with a hypothesis that the propeptide domain acts as an IMC to control both enzymatic activity and competence for secretion.

J Antimicrob Chemother, 1995 Dec, 36(6), 1037 - 41
Resistance to imipenem in Pseudomonas aeruginosa; King A et al.; There was a slow increase in imipenem resistance in Pseudomonas aeruginosa at St . Thomas' Hospital in the 1990s, reaching 3% in 1994 . Of the 94 imipenem-resistant strains, 69% were susceptible to all the other agents tested; 15% were also resistant to one other antibiotic, 5.3% to two, 6.4% to three, 4.3% to four or more compounds . 16% of strains were resistant to at least one other beta-lactam in addition to imipenem . Resistance to other antibiotics was more common among the strains for which imipenem MICs were 4 mg/L than among either imipenem-susceptible or imipenem-resistant (MICs > or = 8 mg/L) strains.

Am J Infect Control, 1995 Dec, 23(6), 396 - 8
Pseudomonas aeruginosa outbreak in a neonatal intensive care unit: a possible link to contaminated hand lotion; Becks VE et al.; This article describes a prolonged outbreak of Pseudomonas aeruginosa . The attack rate of this outbreak was 8.5%, with no associated mortality . Hand lotion contaminated with P . aeruginosa was implicated in the transmission of organisms; removal of this hand lotion ended the outbreak . Contaminated hand lotion applied to clean hands of health care workers may have led to direct inoculation of infants at high risk for infection.

Zhonghua Jie He He Hu Xi Za Zhi, 1995 Dec, 18(6), 357 - 9, 383
{The clinical significance of Pseudomonas aeruginosa typing and R-plasmid and DNA molecule hybridization in patients with cor pulmonale}; Miao J et al.; 600 strains of Pa were typed from the sputa of patients with cor pulmonale in 8 hospitals . P6 type stoods first, accounting for 25.6%, and the types of PA and the difference in distribution of Pseudomonas from different districts and hospitals, might be used as an important parameter in the epidemiological study . 68 of 150 strains from patients with cor pulmonale contained plasmids . 60 isolates harboring plasmids colonies were hybridized with 6 beta-lactamase and 6 aminoglycoside modifying enzyme resistance gene probes . The experiments demonstrated the 3 strains isolated from patients with nosocomial infection came from one same strain and got a new resistance gene during spreading of nosocomial infection, and these isolates contained homologous sequence with OXA-2 and AAC (6')-1b probes.

Intensive Care Med, 1995 Dec, 21(12), 996 - 1002
Use of pulsed-field gel electrophoresis as an epidemiologic tool during an outbreak of Pseudomonas aeruginosa lung infections in an intensive care unit; Talon D et al.; OBJECTIVE: A retrospective study was performed to evaluate the use of DNA polymorphism analysis by pulsed-field gel electrophoresis (PFGE) in assessing the rate of exogenous contamination during an outbreak of Pseudomonas aeruginosa lung infections in an intensive care unit ICU . Another goal was to determine the risk factors, involved in the outbreak.DESIGN: Rectal swabs and tracheal secretions were cultured from all patients upon admission and thereafter once a week throughout their stay in the ICU . Resistance patterns were determined in all P . aeruginosa isolates . We determined the serotypes, pyocin types, plasmid profiles and total DNA macrorestriction patterns for isolates . The restriction fragment length polymorphism (RFLP) of Dra I total DNA digest was studied by PFGE . A retrospective case-control study was performed to determine the risk factors for P . aeruginosa bronchopulmonary colonization . SETTING: The study was carried out in the medical ICU of Besancon University Hospital (France) . RESULTS: The typability, stability and reproducibility of phenotypic markers were not completely satisfactory . Only the RFLP profile satisfied all the criteria for a good typing technique . In four of the 17 patients, P . aeruginosa strains with the same DNA pattern were found . Among the previously reported risk factors for hospital-acquired bronchopulmonary infections, only invasive procedures were determined by multivariate analysis to be significant in our study group . The oropharynx and the bronchial tract are the most likely endogenous sources . CONCLUSION: PFGE-RFLP is a valuable tool for the epidemiologic study of P . aeruginosa . This typing method revealed that exogenous contamination is not always the major source of P . aeruginosa lung infections in mechanically ventilated patients in ICUs.

FEMS Immunol Med Microbiol, 1995 Dec, 12(3-4), 187 - 94
Modulation of Pseudomonas aeruginosa adherence to collagen type I and type II by carbohydrates; Stepinska M et al.; This study was undertaken to examine if receptor recognizing saccharides may be involved in the adherence of Pseudomonas aeruginosa to collagen type I and type II . We performed an adherence inhibition assay: cells of individual P . aeruginosa isolates attached to immobilized collagen type I or type II in the presence of monosaccharides, which could serve as blockers of bacterial receptors . Bacterial binding to collagen type I molecules was inhibited to the highest degree by sugar composition D-galactose/D-mannose/N-acetylneuraminic acid (5:5:1), whereas attachment of P . aeruginosa to collagen type II was inhibited by composition d-glucose/D-galactose (1:1) . The same strains which were sensitive to inhibition of binding to collagen type II by both collagen types, were also sensitive to blocking by composition D-glucose/D-galactose . It suggests that saccharides play a role in adherence of P . aeruginosa to collagen type I and type II, and a common receptor for both types of collagen may be available on the surface of P . aeruginosa cells.

J Cell Sci, 1995 Dec, 108 ( Pt 12), 3695 - 702
Lung surfactant protein A (SP-A) activates a phosphoinositide/calcium signaling pathway in alveolar macrophages; Ohmer-Schrock D et al.; Lung surfactant protein A (SP-A), the main protein component of lung surfactant which lines the alveoli, strongly enhances serum-independent phagocytosis of bacteria by rat alveolar macrophages . We tested if the effect of SP-A is due to interaction with the macrophages or to opsonization of the bacteria . In phagocytosis assays with fluorescein isothiocyanate labeled bacteria, SP-A had no opsonic effect on Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, but enhanced phagocytosis by acting only on the macrophages . We characterized this activation mechanism . With single cell measurements of fura-2 loaded cells we demonstrate that SP-A raises the intracellular free calcium ion concentration 6 to 8 seconds after addition . This calcium mobilization is dose-dependent in that increased SP-A concentrations lead to a higher percentage of responding cells . Additionally, SP-A leads to a dose-dependent and transient generation of inositol 1,4.5-trisphosphate . Release of intracellular stored calcium by SP-A is a prerequisite for its stimulatory effect on phagocytosis, since SP-A-induced enhancement of phagocytosis can be impaired by prior addition of thapsigargin, a Ca(2+)-ATPase inhibitor that leads to depletion of intracellular calcium stores . We conclude that SP-A activates a phosphoinositide/calcium signaling pathway in alveolar macrophages leading to enhanced serum-independent phagocytosis of bacteria.

Zhonghua Hu Li Za Zhi, 1995 Dec, 30(12), 707 - 8
{Experimental test of the bacteriostatic and bactericidal effect of six disinfectants for Pseudomonas aeruginosa}; Zhang XL et al.; Minimal inhibitory concentration (MIC) and minimal bacteriocidal concentration (MBC) of six chosen disinfectants against pseudomonas aeruginosa were tested by the tubular liquid double dilution method . Results showed that 0.06% Chang Kou Jing and 1.5% Supertime are fairly good disinfectants against pseudomonas aeruginosa in infected wound surfaces, postoperative wound dressing, disinfection of surgeons' arms and hands before operation, sterilization of instruments and scrub medical workers' hands after contact with infected patients . The MIC and MBC of the former were 7.5 micrograms/ml and 30.0 micrograms/ml separately, while those of the latter were 11.7 micrograms/ml and 93 micrograms/ml respectively.

Vaccine, 1995 Dec, 13(18), 1750 - 3
Ability of synthetic peptides representing epitopes of outer membrane protein F of Pseudomonas aeruginosa to afford protection against P . aeruginosa infection in a murine acute pneumonia model; Hughes EE et al.; Three synthetic peptides (Nos 9, 10 and 18) representing surface-exposed, linear B-cell epitopes of outer membrane protein F of Pseudomonas aeruginosa were each conjugated to the carriers keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA), with the conjugates being used to immunize mice intranasally . Mice were also immunized intranasally with a KLH/BSA carrier control or with a peptide No . 8 conjugate as a negative control . An immunoglobulin G response reactive with P . aeruginosa whole cells was demonstrated by enzyme-linked immunosorbent assay (ELISA) of sera from mice immunized with peptide 9, 10 or 18, whereas no whole-cell reactivity by ELISA was detected in sera from mice immunized with peptide 8 . Upon pulmonary challenge of immunized mice with a Fisher-Devlin immunotype 4 strain of P . aeruginosa, only those mice immunized with peptide 9 or peptide 10 had a significantly greater survival rate compared to control mice immunized with the carriers alone . Peptides 9 (TDAYNQKLSERRAN) and 10 (NATAEGRAINRRVE) have potential for further development as a protective vaccine against P . aeruginosa infections.

East Afr Med J, 1995 Dec, 72(12), 766 - 9
Empyema thoracis in adults in Saudi Arabia; Grillo IA et al.; Empyema thoracis in adults is an uncommon disease in the Asir region of Saudi Arabia . In a period of seven years (1988 to 1994), 24 patients were treated for empyema thoracis with a hospital incidence of about 23 patients in 100,000 admissions . The community acquired empyemas are more common and less aggressive in non-Saudi patients (six males and one female) as compared to Saudi patients (11 males and 6 females) whose empyemas are mostly nosocomial with an aggressive course . The peak age in both Saudi and non-Saudi patients is 45 years and 25 years respectively, and the right pleura is more commonly affected than the left pleura in both groups . Risk factors include diabetes mellitus, pulmonary tuberculosis, post-pneumonectomy infections, trauma and pneumonia . The commonest organisms grown are Pseudomonas aeruginosa, Klebsiella species and Staphylococcus aureus, although in almost 40% of the patients the empyemas were sterile . The commonest method of treatment was closed thoracostomy tube drainage.

Ann Trop Paediatr, 1995 Dec, 15(4), 269 - 72
Cystic fibrosis in Saudi Arabia: common and rare presentations; Al-Mobaireek KF et al.; The clinical presentations of 12 children with cystic fibrosis seen in King Khalid University Hospital are presented . Ten were of Saudi origin and the other two were African . The mean age of onset of symptoms was 2.3 months, and the mean age at diagnosis was 14.3 months (range 3-48 months) . Seven children were boys and five were girls . All children presented with growth failure, recurrent chest infection and chronic diarrhoea . The parents of 83% of our cases were first-degree relatives . Pseudo-Bartter syndrome was seen in eight children . Sixty-seven per cent of our cases were colonized with Pseudomonas aeruginosa by the time of diagnosis, despite their young age (mean 7 months) . Peripheral neuropathy secondary to vitamin E deficiency, meconium ileus, nasal polyps and gall-stones were present, each in one case . On follow-up, one child died and the other 11 are still alive . We concluded that cystic fibrosis is not rare in Saudi Arabia and that increased awareness of the disease is needed to avoid delay in diagnosis . Efforts should be made to prevent early colonization by Pseudomonas aeruginosa.

Eur J Clin Microbiol Infect Dis, 1995 Dec, 14(12), 1057 - 62
Fluorescence-based DNA fingerprinting elucidates nosocomial transmission of phenotypically variable Pseudomonas aeruginosa in intensive care units; Grundmann H et al.; DNA fingerprinting based on automated laser fluorescence analysis of randomly amplified polymorphic DNA (RAPD-ALFA) is a rapid and convenient technique for detecting clonal relatedness of bacterial isolates of nosocomial concern . During an outbreak of Pseudomonas aeruginosa among five patients in a medical intensive care unit, transmission was not suspected because of the phenotypic variability of the initial isolates . However, DNA fingerprinting by RAPD-ALFA and macrorestriction analysis identified a single genotype (strain A) for isolates from three patients and another genotype (strain B) for isolates from the remaining two patients . Strain A isolates displayed three phenotypes defined by different antibiotypes and distinct colony appearance . Retrospective analysis of DNA fingerprints demonstrated that strain A had been transmitted to the index patient one year previously in a different intensive care unit . The study demonstrates that genetic typing approaches are warranted should epidemiological relatedness be identified between phenotypically variant pathogens . Automated laser fluorescence analysis of PCR fingerprints may facilitate routine screening of bacterial isolates for in-house epidemiological surveillance . Antibiograms are an unsuitable approach for the typing of Pseudomonas aeruginosa.

Biosci Biotechnol Biochem, 1995 Dec, 59(12), 2358 - 9
A toluene-tolerant mutant of Pseudomonas aeruginosa lacking the outer membrane protein F; Li L et al.; The outer membrane protein profiles of a toluene-tolerant mutant, Pseudomonas aeruginosa, strain PAK103, were compared with those of its parent strain PAO1161 . Protein F (OprF), the most abundant outer membrane protein in the parental strain PAO1161, was missing in the toluene-tolerant strain PAK103 . The absence of OprF may lead to the loss of toluene diffusion across in the outer membrane of the mutant cells.

Biokhimiia, 1995 Dec, 60(12), 1964 - 76
{Structure and properties of the common polysaccharide antigen of Pseudomonas aeruginosa bacteria (review)}; Knirel' IuA et al.; The review is devoted to a surface carbohydrate antigen of the bacterium Pseudomonas aeruginosa which is common for the majority of the species and has a lipopolysaccharide nature . The occurrence, detection, isolation, structure, expression on the cell surface, interaction with antibodies, an antibiotic and a bacteriophage as well as the immunotherapeutic potential of the common polysaccharide antigen are discussed.

Antimicrob Agents Chemother, 1995 Dec, 39(12), 2822 - 6
In vitro antibacterial activity of DU-6859a, a new fluoroquinolone; Nakane T et al.; The in vitro antibacterial activity of DU-6859a, a new fluoroquinolone, against a wide variety of clinical isolates was evaluated and compared with those of tosufloxacin, ofloxacin, ciprofloxacin, and sparfloxacin . DU-6859a showed potent broad-spectrum activity against gram-positive, gram-negative, and anaerobic bacteria, and its activity was greater than those of the control quinolones . By comparison of MICs at which 90% of strains are inhibited, DU-6859a had potent activity against bacteria resistant to the control quinolones . The time-killing curves of quinolones showed that the number of viable cells decreased rapidly during 2 to 4 of incubation, and regrowth was not seen even after 8 h incubation . At a concentration of four times the MIC, the frequencies of appearance of spontaneous mutants of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa resistant to DU-6859a were < or = 4.0 x 10(-9) to 1.9 x 10(-8) . The 50% inhibitory concentrations of DU-6859a were 0.86 and 1.05 micrograms/ml for the supercoiling activities of DNA gyrases isolated from E . coli and P . aeruginosa, respectively . The rank order of the 50% inhibitory concentrations observed for both DNA gyrases roughly paralleled the MICs.

Antimicrob Agents Chemother, 1995 Dec, 39(12), 2813 - 5
Activity of lipopolysaccharide-binding protein-bactericidal/permeability-increasing protein fusion peptide in an experimental model of Pseudomonas sepsis; Opal SM et al.; A chimeric protein consisting of the N-terminal domain of lipopolysaccharide-binding protein and the C-terminal domain of bactericidal/permeability-increasing protein demonstrated a dose-dependent survival benefit (P = 0.001) and reduced endotoxin levels (P < 0.01) in neutropenic rats with Pseudomonas aeruginosa sepsis . This lipopolysaccharide-binding protein-bactericidal/ permeability-increasing peptide has favorable pharmacokinetics and antiendotoxin properties which may be of value for human sepsis.

Antimicrob Agents Chemother, 1995 Dec, 39(12), 2702 - 7
Critical influence of timing of administration of granulocyte colony-stimulating factor on antibacterial effect in experimental endocarditis due to Pseudomonas aeruginosa; Vignes S et al.; The effect of human recombinant granulocyte colony-stimulating factor (hrG-CSF) in rabbits with aortic endocarditis due to Pseudomonas aeruginosa was investigated . hrG-CSF significantly increased the number of polymorphonuclear neutrophils in blood and in cardiac vegetations and the expression of the adhesin molecule CD11b on the surface of polymorphonuclear neutrophils compared with those of animals that had not received hrG-CSF . When treatment was started 72 h after bacterial challenge, hrG-CSF alone had no antibacterial effect and did not enhance the efficacy of ciprofloxacin when used in combination, even with the higher dosing regimen used (50 micrograms/kg of body weight subcutaneously every 12 h for 4 days), in terms of number of positive blood cultures, bacterial counts in vegetations, and survival . In contrast, when treatment was started 30 min prior to bacterial challenge, hrG-CSF (50 micrograms/kg injected every 12 h) decreased bacterial titers in vegetations 72 h later (6.5 +/- 0.9 versus 7.9 +/- 0.9 log10 CFU/g of vegetation for hrG-CSF and controls, respectively; P = prophylactic administration of hrG-CSF did not increase the antibacterial effect of ciprofloxacin . We concluded that the antibacterial effect of hrG-CSF in experimental endocarditis was related to the timing of its administration since hrG-CSF demonstrated a significant but transient antimicrobial effect only when treatment was initiated before bacterial challenge.

Antimicrob Agents Chemother, 1995 Dec, 39(12), 2645 - 9
Effects of free and liposome-encapsulated antibiotics on adherence of Pseudomonas aeruginosa to collagen type I; Trafny EA et al.; The adherence of 27 clinical Pseudomonas aeruginosa strains to collagen type I was investigated by using a solid-phase assay . The influence of free antibiotics (amikacin, gentamicin, piperacillin, bacitracin, and polymyxin B) and liposome-entrapped antibiotics (amikacin and polymyxin B) on bacterial attachment to collagen type I was examined . The greatest inhibitory effect was shown for free and liposomal amikacin, which decreased the attachment of 74 and 100% of tested strains, respectively . The mean percent attachment (+/- standard deviation) in the presence of free amikacin was 65.7% (+/- 12.0%) as measured by solid-phase assay . In the presence of liposomal amikacin, the attachment ranged from 17.3% (+/- 6.0%) to 42.1% (+/- 9.4%), depending on the antibiotic solvent . In contrast, polymyxin B, even at a subinhibitory concentration, enhanced attachment of all P . aeruginosa isolates to collagen . Liposomal polymyxin B displayed a protective effect only when the encapsulated drug was of a low concentration . Application of liposome-encapsulated amikacin may be advantageous in injured tissues in which extracellular matrix structures become exposed.

Jpn J Antibiot, 1995 Dec, 48(12), 1935 - 8
{Active transport of fosfomycin into cells of Escherichia coli, multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus}; Tsuruoka T et al.; We examined effect of fosfomycin (FOM) on growth of Escherichia coli (E . coli) NIHJ JC-2, multidrug-resistant Pseudomonas aeruginosa (P . aeruginosa) PFS80 and Staphylococcus aureus (S . aureus) Smith . FOM inhibited the growth of these organisms at 0.1 approximately 0.5, 10 approximately 50 or 5 approximately 50 micrograms ml, respectively . In E . coli, FOM clearly lyzed the cells at 0.5 microgram/ml . These 3 bacteria incorporated radiolabeled FOM proportionately to incubation time . Intracellular concentration of FOM was estimated by considering the water content of E . coli cells . The ratio of intracellular to extracellular concentrations of FOM was larger than 1 after 5 approximately 10 min . incubation with FOM and reached about 7 after 40 min . FOM was incorporated actively into P . aeruginosa over extracellular concentration after 40-min . incubation on the basis of the above-mentioned water content . It was suggested that FOM was incorporated actively into various bacterial cells, and inhibited efficiently cell wall peptidoglycan synthesis, thus inhibited bacterial growth or lyzed the bacterial cells.

J Clin Microbiol, 1995 Dec, 33(12), 3191 - 3
Evaluation of E-Test for determination of antimicrobial MICs for Pseudomonas aeruginosa isolates from cystic fibrosis patients; Marley EF et al.; We determined the E-Test and National Committee for Clinical Laboratory Standards standardized agar dilution MICs of ceftazidime, ciprofloxacin, piperacillin, and tobramycin for Pseudomonas aeruginosa during tests of 100 rough and mucoid P . aeruginosa isolates from cystic fibrosis patients . The levels of agreement (+/- 1 log2 dilution) between quantitative E-Test and agar dilution MIC results were 80, 97, 73, and 89% for ceftazidime, ciprofloxacin, piperacillin, and tobramycin, respectively . Comparison of the results after converting the MIC data to qualitative categories (susceptible, intermediate, and resistant) yielded levels of agreement of 84, 96, 88, and 93% for the same agents, respectively . Of the 39 qualitative discrepancies, 36 were minor and 3 were very major . We conclude that use of the E-Test is easier and more practical than use of the agar dilution method for most laboratories and that the E-Test furnishes results which are at least as accurate as those obtained by the agar dilution method . However, the higher cost of the E-Test method would likely discourage most laboratories from selecting it over disk diffusion for routine antimicrobial susceptibility testing of P . aeruginosa isolates from cystic fibrosis patients.

Microbiology, 1995 Dec, 141 ( Pt 12), 3193 - 205
A Bordetella pertussis fepA homologue required for utilization of exogenous ferric enterobactin; Beall B et al.; The bfeA (Bordetella ferric enterobactin) receptor gene was cloned from a Bordetella pertussis chromosomal library by using a screen in Escherichia coli to detect iron-repressed genes encoding exported proteins translationally fused to the E . coli phoA gene . The bfeA gene encoded a protein with a molecular mass of approximately 80 kDa and about 50% amino acid sequence identity to both the fepA- and pfeA-encoded enterobactin receptors of E . coli and Pseudomonas aeruginosa, respectively . Enterobactin prepared from iron-starved E . coli cultures supported growth of B . pertussis and Bordetella bronchiseptica in the presence of the iron chelator ethylenediamine-di-(o-hydroxyphenylacetic acid) (EDDA) . Expression of the bfeA gene was induced by low iron availability, and iron-regulated expression appeared to be dependent upon the presence of the sequence contained within 370 bp upstream of the bfeA structural gene . An internal fragment of the bfeA structural gene and flanking regions were shown by Southern analysis to be highly conserved among Bordetella species . Insertional inactivation of bfeA in both B . pertussis and B . bronchiseptica greatly impaired their ability to grow in the presence of enterobactin and EDDA . These findings suggest that enterobactin produced by other respiratory flora could aid in the colonization of the respiratory tract by Bordetella species.

J Am Optom Assoc, 1995 Dec, 66(12), 775 - 9
The effects of short-term contact lens wear on adherence of Pseudomonas aeruginosa to human corneal cells; Harding AS et al.; BACKGROUND: Ulcerative keratitis is the most serious complication of contact lens wear, with the majority of infections being attributed to Pseudomonas aeruginosa . The degree to which bacteria adhere to the cornea may indicate its susceptibility to infection . It has been found that long-term contact lens wear leads to increased adherence of Pseudomonas aeruginosa to corneal epithelial cells . This study examines the effect of short-term contact lens wear . MEANS: Cells were collected using a non-contact corneal irrigation system from a total of 16 subjects fitted with tight and loosely-fitted soft contact lenses . The control group consisted of 10 subjects with no recent contact-lens-wearing experience, eight of whom were later fitted with lenses to form a neophyte group . Six contact lens wearers formed the experienced group . After wearing lenses for a 30-hour period, including overnight, the collected corneal cells were incubated with Pseudomonas aeruginosa, differentially stained with Acridine orange and examined under fluorescence microscopy . RESULTS: The number of bacteria adhering to the cells was determined for the control group, neophyte and experienced groups . The frequency distribution profiles were similar for all groups and did not vary significantly between lens-wearing and non-wearing conditions, between neophyte and experienced wearers, or with lens fit . CONCLUSIONS: Using the technique reported, short-term extended contact lens wear produced minimal detectable changes in the potential of corneal epithelium cells to bind bacteria.

Epidemiol Mikrobiol Imunol, 1995 Dec, 44(4), 169 - 70
{The effect of subinhibitory concentrations of quinolone and macrolide antibiotics on production of thermolabile hemolysins in Pseudomonas aeruginosa}; Hybenova D et al.; The authors investigated the effect of subinhibitory concentrations (sub-MICs) of selected quinolones (enoxacine, nalidixic acid, norfloxacine) and macrolid antibiotics (erythromycin, roxitromycin) on the production of thermolabile haemolysin (phospholipase C) of P . aeruginosa . The activity of phospholipase C was markedly reduced by norfloxacine (more than 80%) and enoxacine (75 - 80%) in all sub-MICs . Nalidixic acid inhibited phospholipase C in 1/4 of MIC (75%) . As to macrolid antibiotics the greatest inhibition was caused by erthromycin in 1/4 and 1/8 MIC (more than 90%) . 1/16 MIC of roxitromycin did not influence the activity of the investigated enzyme and other tested sub-MICs caused its reduction to cca one half.

Epidemiol Mikrobiol Imunol, 1995 Dec, 44(4), 161 - 4
{Mobilization of genetic determinants of antibiotic resistance in strains of Pseudomonas aeruginosa}; Babalova M et al.; The authors describe a phenomenon of mobilisation of antibiotic resistance from non-transferring strains of P . aeruginosa by cultivation with strains of P . aeruginosa capable to transfer determinants of antibiotic resistance to a susceptible recipient strain, by triparental cross . In this report three strains of P . aeruginosa (No . 282, 283 from Bata's Hospital in Zlin and 76 from Frankfurt University Clinics) are described capable to mobilise for transfer the resistance determinants in four strains of P . aeruginosa (No . 76, 229, 47 and 125 from Frankfurt University Clinics) with multiple antibiotic resistance which itself was not transferable to recipient strains . By an indirect selection method it was assessed, that all six antibiotics (cephalotin-cefazoline, carbenicillin, kanamycin, cefotaxime, ceftazidime and aztreonam), present in resistance spectrum of intermediary recipient strains, were mobilised for transfer . Imipenem and ofloxacin were not mobilised for transfer . In the second and third cycles of transfer the authors confirmed the stability and transferability of the block of six antibiotic resistance determinants, which were not previously transferable.

Thorax, 1995 Dec, 50(12), 1301 - 4
Genetic and clinical features of patients with cystic fibrosis diagnosed after the age of 16 years; Gan KH et al.; BACKGROUND--Cystic fibrosis is usually diagnosed in childhood, but a number of patients are not diagnosed until adulthood . The aim of this study was to investigate whether patients diagnosed at an older age had a different genetic constitution, manifestations of disease, and prognosis from those diagnosed at an early age . METHODS--Clinical data and results of lung function tests and DNA analysis of 143 adult patients with cystic fibrosis were entered into a computerised database . Patients diagnosed before their 16th birthday (early diagnosis, ED) were compared with those diagnosed at 16 years of age or older (late diagnosis, LD) . RESULTS--Mean age of diagnosis of the ED group was 4.6 years compared with 27.7 years for the LD group . Mean (SD) percentage predicted pulmonary function was better for the LD group than for the ED group: forced expiratory volume in one second (FEV1) 72.5 (31.1)% and 52.0 (24.8)%, and forced vital capacity (FVC) 89.8 (25.7)% and 71.9 (23.0)%, respectively . Colonisation with Pseudomonas aeruginosa was present in 70% of the ED group and 24% of the LD group . In the ED group 81% had pancreatic insufficiency compared with only 12% of the LD group . None of the LD group was homozygous for delta F508 compared with 58% of the ED group . In the LD group 72% were compound AF508 heterozygotes and 28% had two non-delta F508 mutations . CONCLUSIONS--Among this group of 143 adult patients with cystic fibrosis late diagnosis is caused mainly by delayed expression and mild progression of clinical symptoms . Late diagnosis is associated with milder pulmonary disease, less pancreatic insufficiency, and different cystic fibrosis mutations . Since mortality in cystic fibrosis depends on the progression of pulmonary disease, patients with a late diagnosis have a better prognosis than those diagnosed early.

Thorax, 1995 Dec, 50(12), 1246 - 52
Long term effect of erythromycin therapy in patients with chronic Pseudomonas aeruginosa infection; Fujii T et al.; BACKGROUND--Diffuse panbronchiolitis is a chronic infection of the lower respiratory tract common among the Japanese people, with a persistent Pseudomonas aeruginosa infection in the late stage and sustained neutrophil retention in the airways . The long term effect of erythromycin was examined retrospectively in a group of patients with diffuse panbronchiolitis, with and without P aeruginosa infection, and the relationship between drug-induced bacterial clearance and clinical improvement was investigated . METHODS--The history, daily volume of sputum, type of organisms in sputum cultures, pulmonary function tests, arterial blood gas tensions, and chest radiographs were compared in 16 patients with diffuse panbronchiolitis with P aeruginosa infection and 12 without . The total and differential cell counts in the bronchoalveolar lavage (BAL) fluid were compared in 14 of the 28 patients (five of whom were infected with P aeruginosa) before and after 1-12 months of treatment with erythromycin (600 mg/day) . The outcome of treatment in patients showing clearance of organisms on repeated sputum cultures was compared with that in those demonstrating persistence of bacteria in the sputum and patients with normal flora . RESULTS--Erythromycin improved respiratory function and arterial blood gas tensions irrespective of the presence or absence of P aeruginosa in the sputum . Treatment also resulted in a reduction in the BAL fluid total cell count and the percentage of neutrophils in both groups of patients . There were no differences between patients in whom the bacteria cleared and those with persistent bacteria or patients with a normal flora with regard to the degree of improvement of respiratory function, arterial blood gas tensions, and BAL fluid cell composition . CONCLUSION--The results suggest that the efficacy of erythromycin in diffuse pan-bronchiolitis may be due to anti-inflammatory effect, independent of P aeruginosa infection or bacterial clearance.

Mol Mar Biol Biotechnol, 1995 Dec, 4(4), 331 - 7
Rhamnolipid biosurfactant enhancement of hexadecane biodegradation by Pseudomonas aeruginosa; Shreve GS et al.; Mutants of Pseudomonas aeruginosa that produce and do not produce rhamnolipid biosurfactant are used to investigate the influence of cell-associated biosurfactant on cellular association with the hydrocarbon-water interface and on hydrocarbon uptake . Rhamnolipid-nonproducing mutant 65E12 of P . aeruginosa is unable to grow in minimal media containing hexadecane as a carbon source in the absence of exogenously added surfactant . Mutant PG201::rhlR grows very slowly in the absence of exogenously added surfactants . Both mutants are deficient in the positive regulatory gene controlling the activation of rhamnolipid synthesis . 65E12 is a double mutant that is also deficient in lipopolysaccharide synthesis . However, growth on hexadecane may be restored to varying degrees when small amounts of purified rhamnolipids or the synthetic anionic surfactant alkyl benzene sulfonate (ABS) is added to the cultures . Rhamnolipid biosurfactant is shown to be approximately 9 times more effective than the structurally similar synthetic anionic surfactant ABS in solubilizing hydrocarbon into the aqueous phase . Physical characteristics of the rhamnolipid and ABS micelles as determined by laser light scattering are described to explain the greater effectiveness of the rhamnolipid in solubilizing hexadecane . The cellular attachment to hydrocarbon-water interfaces and cellular aggregation of the wild-type and mutant strains are examined in the presence and absence of rhamnolipid or synthetic ABS surfactants . Differences in observed hexadecane degradation rates are explained on the basis of emulsified hexadecane concentration, cell surface hydrophobicity, and cellular localization in the culture.

J Formos Med Assoc, 1995 Dec, 94(12), 760 - 4
Clinical evaluation of ciprofloxacin ophthalmic solution in the treatment of refractory bacterial keratitis; Tsai AC et al.; Ciprofloxacin is a fluoroquinolone antimicrobial agent inhibiting bacterial DNA gyrase, with good in vitro and in vivo activity against many Gram-positive and Gram-negative ocular pathogens . It has low toxicity, low resistance rate and low minimum inhibitory concentration . The purpose of this study was to evaluate the efficacy of ciprofloxacin in treating bacterial keratitis refractory to conventional therapy . Thirty patients with smear-proven bacterial ulcers were treated by conventional therapy . Of these, cultures were positive in 28 (93.3%) patients . Pseudomonas aeruginosa was isolated in 13 (46.4%) patients, nontuberculous mycobacteria in nine (32.1%) and other bacteria in six (21.4%) . Fifteen patients (50%) were cured with conventional therapy . Four patients (13.3%) underwent surgery due to impending corneal perforation . Eleven patients were shifted to ciprofloxacin therapy because of poor results with conventional treatment . Of these, eight (72.7%) patients were treated successfully . No adverse events were encountered except a white crystalline precipitate in two cases which resolved spontaneously after discontinuation of therapy . In view of its effectiveness and low toxicity, ciprofloxacin should be considered in treating bacterial keratitis which is refractory to conventional therapy.

J Bacteriol, 1995 Dec, 177(24), 7194 - 201
Role of the ferric uptake regulator of Pseudomonas aeruginosa in the regulation of siderophores and exotoxin A expression: purification and activity on iron-regulated promoters; Ochsner UA et al.; The cloned Pseudomonas aeruginosa fur (ferric uptake regulator) gene was overexpressed in P . aeruginosa by using a T7 expression system, and the Fur protein (PA-Fur) was purified by using a combination of ion-exchange chromatography and metal affinity chromatography . The DNA binding activity of the PA-Fur protein was confirmed by gel mobility shift assays and DNase I footprints of the synthetic DNA fragment GATAAT GATAATCATTATC, representing a perfect "Fur box" . In addition, it was shown that PA-Fur is capable of binding to promoter and operator determinants of the tightly iron-regulated Escherichia coli fepA-fes enterobactin gene system . The activity of PA-Fur on the promoters of iron-regulated genes involved in the production of two siderophores, pyochelin and pyoverdin, and in the expression of exotoxin A was investigated . Data indicating that the promoters of the pchR gene, encoding a transcriptional activator for pyochelin synthesis, and of the pvdS gene, encoding a positive regulator for pyoverdin production, are specifically recognized by Fur-Fe(II) are presented, suggesting that PA-Fur represses expression of pchR and pvdS during growth in an iron-replete environment . However, neither the promoter region of the gene encoding exotoxin A (toxA) nor the promoters of the regAB operon, required for toxA expression, interacted with high concentrations of purified PA-Fur . These data indicate that iron regulation of exotoxin A production involves additional factors which may ultimately be under the control of PA-Fur.

J Bacteriol, 1995 Dec, 177(24), 7019 - 25
Molecular cloning and characterization of a chemotactic transducer gene in Pseudomonas aeruginosa; Kuroda A et al.; A Pseudomonas aeruginosa mutant, defective in taxis toward L-serine but responsive to peptone, was selected by the swarm plate method after N-methyl-N'-nitrosoguanidine mutagenesis . The mutant, designated PCT1, was fully motile but failed to show chemotactic responses to glycine, L-serine, L-threonine, and L-valine . PCT1 also showed weaker responses to some other commonly occurring L-amino acids than did the wild-type strain PAO1 . A chemotactic transducer gene, denoted pctA (Pseudomonas chemotactic transducer A), was cloned by phenotypic complementation of PCT1 . Nucleotide sequence analysis showed that the pctA gene encodes a putative polypeptide of 629 amino acids with a calculated mass of 68,042 . A hydropathy plot of the predicted polypeptide suggested that PctA may be an integral membrane protein with two potential membrane-spanning regions . The C-terminal domain of PctA showed high homology with the enteric methyl-accepting chemotaxis proteins (MCPs) . The most significant amino acid sequence similarity was found in the region of MCPs referred to as the highly conserved domain . The pctA gene was inactivated by insertion of a kanamycin resistance gene cassette into the wild-type gene, resulting in the same observed deficiency in taxis toward L-amino acids as PCT1 . In vivo methyl labeling experiments with L-{methyl-3H}methionine showed that this knockout mutant lacked an MCP with a molecular weight of approximately 68,000.

Am J Respir Crit Care Med, 1995 Dec, 152(6 Pt 1), 2150 - 6
Neutrophil-induced lung protection and injury are dependent on the amount of Pseudomonas aeruginosa administered via airways in guinea pigs; Terashima T et al.; We investigated the roles of neutrophils in mediating both the protective effect against bacterial infection and the harmful effect of lung injury induced after the intratracheal instillation of live bacteria . We examined the mortality rate, lung injury, and bacterial clearance following the intratracheal instillation of Pseudomonas aeruginosa in low (10(4) colony-forming units {CFU}) and high doses (10(8) CFU) in normal (control) guinea pigs, others made neutropenic with cyclophosphamide (CPA), and guinea pigs made neutrophilic with recombinant granulocyte colony-stimulating factor (rG-CSF) . Lung injury was assessed by the ratio of the concentration of 125I-labeled albumin in lung tissue to that in plasma (T/P) and the animals' lung weight-to-body weight (LW/BW) ratio . With 10(4) CFU, the CPA group showed an increased T/P ratio of 0.22 +/- 0.03 versus 0.14 +/- 0.01 in the control and 0.11 +/- 0.01 (mean +/- SEM) in the rG-CSF groups (p < 0.01) . Viable bacteria were recovered from bronchoalveolar lavage fluid (BALF) in the CPA group . Neutrophil recruitment was observed in the lungs of animals in the control and rG-CSF groups . With 10(8) CFU, the mortality rate was increased in the rG-CSF group (7 of 10) as compared with the control (0 of 9) and CPA groups (1 of 9) (p < 0.05), which reflected an increased LW/BW (g/kg) ratio (16 +/- 2 versus 12 +/- 1) in the CPA group (p < 0.05) . We conclude that neutrophils protect against lung injury during low-level bacterial challenge, but enhance lung injury and contribute to mortality during high-level bacterial challenge.

Am J Respir Crit Care Med, 1995 Dec, 152(6 Pt 1), 2111 - 8
Inflammatory cytokines in cystic fibrosis lungs; Bonfield TL et al.; Chronic pulmonary infection with Pseudomonas aeruginosa continues to be the major cause of morbidity and mortality in cystic fibrosis (CF) . Several characteristics of CF, including the excessive influx of neutrophils into the airways, cachexia, and hyperglobulinemia, could reflect the effects of cytokines, such as interleukin-1 (IL-1), IL-6, IL-8, and tumor necrosis factor (TNF-alpha) . We hypothesized that these pro-inflammatory cytokines, produced by alveolar macrophages in response to pseudomonas and/or other microorganisms, promote the destructive inflammatory process in the lung . We evaluated bronchoalveolar lavage (BAL) fluid and BAL macrophages from 22 CF patients and 13 healthy control (HC) subjects, measuring soluble TNF-alpha, IL-1 beta, IL-6, and IL-8 and the regulatory molecules TNF soluble receptor (TNF-sR), IL-1 receptor antagonist (IL-1Ra), and IL-10 (cytokine synthesis inhibitory factor) . Levels of the proinflammatory cytokines were higher in CF versus HC BAL (p < or = 0.05 for IL-1, TNF, and IL-8; p = 0.06 for IL-6) . In contrast, HC BAL contained significantly more IL-10 than CF BAL (p < 0.05), but TNF-sR and IL-1Ra were similar . Immunocytochemistry demonstrated a higher percentage of CF than control BAL macrophages expressing intracellular cytokines (p < 0.05) . Thus, enhanced macrophage production of proinflammatory cytokines and decreased production of the regulatory molecule IL-10 may have important roles in the pathogenesis of CF lung disease.

Am J Respir Crit Care Med, 1995 Dec, 152(6 Pt 1), 1910 - 6
Neutrophil-derived long-lived oxidants in cystic fibrosis sputum; Witko-Sarsat V et al.; We evaluated long-lived oxidant potential in the sputum of patients with cystic fibrosis (CF) by quantitating the methionine-inhibitable, long-lived oxidant fraction of sputum, referred to as the chloramines . Taurine, the preferred amino acid substrate for chloramine formation, and myeloperoxidase (MPO), the chlorinated oxidant-generating enzyme, were also quantitated . As compared with the sputum of asthmatic subjects, the sputum of CF patients contained high concentrations of chloramines along with high levels of taurine and active MPO . A negative correlation between chloramine and taurine was found in the sputum of CF patients . No correlation was found between the density of Pseudomonas aeruginosa and the level of chloramines, taurine, or MPO . In contrast, respiratory parameters (%FEV or %FVC) and a nutritional index correlated positively with chloramine levels, whereas negative correlations were observed with taurine and MPO . In addition, the effect of antibiotic therapy, which significantly increased chloramine and decreased taurine levels, supported a beneficial effect of chloramines on overall clinical status . Our findings support a dual role of long-lived oxidants at the site of airway inflammation in CF, one component of which is their ability to mediate oxidative stress and the other a beneficial effect that may be partly explained by their inhibitory effect on antiprotease defense systems.

J Infect Dis, 1995 Dec, 172(6), 1519 - 27
Differences in therapeutic efficacy among cell wall-active antibiotics in a mouse model of gram-negative sepsis; Bucklin SE et al.; The in vivo efficacy of three cell wall-active antibiotics, imipenem, meropenem, and ceftazidime, was compared in mice rendered hypersusceptible to the pathophysiologic effects of lipopolysaccharide by treatment with D-galactosamine . When CF-1 mice were administered Escherichia coli, D-galactosamine, and saline intraperitoneally, an LD50 was achieved at an inoculum of approximately 2 x 10(4) cfu . Administration of antibiotic at 20 mg/kg resulted in significant but widely variable protective efficacy from E . coli lethality among the three antibiotics . At this dose, an approximately 3-fold increase in LD50 was observed with either meropenem or ceftazidime, whereas administration of imipenem resulted in an approximately 8-fold increase in LD50 (P = .0053) . When the dose of antibiotic was decreased to 2 mg/kg, neither meropenem nor ceftazidime could provide measurable protection, whereas imipenem was almost fully protective (P < .002) . These differences in protective efficacy were also noted with experimental Pseudomonas aeruginosa but not Staphylococcus aureus infection.

J Bacteriol, 1995 Dec, 177(23), 6718 - 26
Structural elucidation of the lipopolysaccharide core region of the O-chain-deficient mutant strain A28 from Pseudomonas aeruginosa serotype 06 (International Antigenic Typing Scheme); Masoud H et al.; The lipopolysaccharide (LPS) of the Pseudomonas aeruginosa serotype 06 rough-type mutant A28 was isolated by a modified phenol-chloroform-petroleum ether extraction method . Deoxycholate-polyacrylamide gel electrophoresis indicated a single band with mobility similar to that of the complete core region of the wild-type parent serotype 06 (International Antigenic Typing Scheme) strain . Compositional analysis of the LPS indicated that the core oligosaccharide was composed of D-glucose (three units), L-rhamnose (one unit), 2-amino-2-deoxy-D-galactose (one unit), L-glycero-D-manno-heptose (two units), 3-deoxy-D-manno-octulosonic acid (two units), L-alanine (one unit), and phosphate (two units) . Under the mild conditions of hydrolysis with methanolic hydrogen chloride, a 7-O-carbamoyl substituent was observed on the second heptose residue . The glycan structure of the LPS was determined by employing one- and two-dimensional nuclear magnetic resonance spectroscopy and mass spectrometry-based methods with a backbone oligosaccharide that was obtained from the LPS by deacylation, dephosphorylation, and reduction of the terminal glucosamine . On the basis of the results of the present study and our earlier work with the P . aeruginosa 06-derived core-defective mutant R5 (H . Masoud, E . Altman, J . C . Richards, and J . S . Lam, Biochemistry, 33:10568-10578, 1994), a structural model for the complete core oligosaccharide is proposed.

Infect Immun, 1995 Dec, 63(12), 4921 - 3
Pyocyanin from Pseudomonas aeruginosa inhibits prostacyclin release from endothelial cells; Kamath JM et al.; Pseudomonas aeruginosa pneumonia causes a vasculitis of small pulmonary arteries . While the fully developed lesion demonstrates vessel wall necrosis, the early lesion is remarkable for preservation of viable endothelium despite vessel wall invasion by bacteria . Pyocyanin, an exoproduct of P . aeruginosa, markedly inhibited prostacyclin production by pulmonary artery endothelial cells without causing cell lysis . Pyocyanin might after vascular homeostasis in the absence of cytolysis.

Infect Immun, 1995 Dec, 63(12), 4868 - 76
Cloning and phenotypic characterization of fleS and fleR, new response regulators of Pseudomonas aeruginosa which regulate motility and adhesion to mucin; Ritchings BW et al.; This work has identified two genes (designated fleS and fleR) in Pseudomonas aeruginosa which are highly homologous to members of the subclass of two-component systems involved in transcriptional regulation of a diverse array of genes from sigma 54 promoters . The genes are located upstream from fliE, a flagellar gene of P . aeruginosa, and they are arranged in a putative fleSR operon . FleS has a predicted molecular mass of 43.87 kDa and shows strong homology to histidine kinases which in other two-component systems have been shown to be sensor proteins . FleR has a predicted molecular mass of 51.26 kDa and is homologous to other regulatory proteins that bind to specific upstream activating elements to enhance transcription of genes with sigma 54 promoters . The fleSR system is believed to control both flagellar synthesis and adhesion to mucin . Several lines of evidence are presented . (i) A nonpiliated mutant of P . aeruginosa PAK containing a gentamicin cassette in fleR is nonmotile and nonadhesive . (ii) The fleR mutant regained motility and adhesion when complemented with a wild-type copy of fleR . (iii) A Western blot (immunoblot) of the fleR mutant showed no synthesis of flagellin, and electron microscopy of the fleR mutant confirmed the lack of flagella . Previous work has shown that flagellar mutants with mutations in fliA (sigma 28) or fliC (the structural gene for flagellin) retain adhesion; therefore, these new observations suggest that FleSR regulates both the expression of flagella and the nonpilus adhesin(s) for mucin or that one of the flagellar proteins (other than flagellin) may be responsible for adhesion to mucins.

J Trauma, 1995 Dec, 39(6), 1141 - 6; discussion 1146-7
Recombinant human granulocyte colony-stimulating factor treatment improves macrophage suppression of granulocyte and macrophage growth after burn and burn wound infection; Gamelli RL et al.; Granulocyte and macrophage production after burn injury or burn wound infection is significantly reduced and further compromised by endotoxin (ET) . Moreover, the macrophage seems to be the major source of this bone marrow suppression . We sought to determine if recombinant human granulocyte colony-stimulating factor (rhG-CSF), a hematopoietic growth factor that is capable of improving survival after experimental burn wound sepsis, altered postburn macrophage-mediated marrow suppression . Groups of male BDF1 mice (n = 6 to 10) receiving a 15% total body surface area burn +/- infection (B or B + I) with Pseudomonas aeruginosa were injected with 100 ng rhG-CSF twice daily . On day 3, peritoneal-elicited macrophages (5 x 10(6) cells/mL) from either rhG-CSF-treated or control (5% dextrose in water) mice were incubated +/- ET (300 ng/mL) . The resultant macrophage supernatant was added to cultures of target marrow granulocyte-macrophage progenitor cells (GM-CFC) at a volume of 1:10 . The GM-CFC growth as a percentage of cultures not containing macrophage supernatant were compared and reductions in the number of GM-CFC taken as an index of marrow suppression . Macrophages obtained from B and B + I animals reduced target GM-CFC growth, compared with macrophages from normal animals (B vs . normal animals p < 0.05) . In addition, ET-stimulated macrophages induced further bone marrow suppression for all three groups (p < 0.01) . Macrophages from granulocyte colony-stimulating factor-treated animals caused significantly less bone marrow suppression, compared with untreated animals for all groups (p < 0.05 to 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

J Biol Chem, 1995 Nov 24, 270(47), 28246 - 50
Characterization of a phosphoprotein phosphatase for the phosphorylated form of nucleoside-diphosphate kinase from Pseudomonas aeruginosa; Shankar S et al.; Nucleoside-diphosphate kinase (ATP:nucleoside-diphosphate phosphotransferase, EC 2.7.4.6; NDP kinase) is an important enzyme for the maintenance of the correct cellular levels of nucleoside triphosphates (NTPs) and their deoxy derivatives (dNTPs) and is involved in the regulation of cellular development . The enzyme is under the dual control of algR2 and algH in Pseudomonas aeruginosa . We report here the purification and characterization of a protein that dephosphorylates the phosphorylated intermediate form of the P . aeruginosa NDP kinase (Ndk) . Dephosphorylation of Ndk phosphate leads to loss of its enzymatic activity . The 10.1-kDa polypeptide shows 77% homology at the N terminus with the Spo0E phosphatase, identified as a negative regulator of sporulation in Bacillus subtilis and 66% with the human Bax protein, identified as an effector of programmed cell death . The phosphatase termed Npp showed varied specificity toward phosphorylated Ndks from different sources including human erythrocyte Ndk phosphate . Its activity toward other histidine phosphates such as CheA or the alpha-subunit of succinyl-CoA synthetase or phosphoesters such as p-nitrophenyl phosphate was quite limited . Npp was stable at room temperature up to 2 h and required Mg2+ for activity . The presence of a phosphatase capable of dephosphorylating the phosphorylated form of P . aeruginosa Ndk represents an interesting and efficient mode of post-translational modification of an enzyme crucial to cellular development.

Biochem Biophys Res Commun, 1995 Nov 22, 216(3), 874 - 80
Biochemical characterization and posttranslational modification of AlgU, a regulator of stress response in Pseudomonas aeruginosa; Schurr MJ et al.; AlgU is homologous to the extreme heat shock sigma factor sigma E from enteric bacteria . In this work, AlgU was overproduced and purified and its function investigated at the biochemical level . AlgU was shown to associate with RNA polymerase and direct transcription of a target promoter . AlgU also exhibited multiple isoforms detected by 2D gel analysis . Treatment with a Ser/Thr phosphatase shifted the distribution of isoforms towards the basic side on 2D gels, suggesting that posttranslational modifications of AlgU may involve phosphorylation . The underphosphorylated forms of AlgU copurified with RNA polymerase . It is possible that phosphorylation affects AlgU activity or its stability.

Structure, 1995 Nov 15, 3(11), 1225 - 33
Crystal structure of the di-haem cytochrome c peroxidase from Pseudomonas aeruginosa; Fulop V et al.; BACKGROUND: Cytochrome c peroxidase from Pseudomonas aeruginosa (PsCCP) represents a new class of peroxidases which work without the need to create a semi-stable free radical for catalysis . The enzyme is located in the bacterial periplasm where its likely function is to provide protection against toxic peroxides . The soluble 323-residue single polypeptide chain contains two covalent c-type haems with very different properties: one of them is a low-potential (-330 mV) centre where hydrogen peroxide is reduced (the peroxidatic site); the other is a high-potential (+320 mV) centre which feeds electrons to the peroxidatic site from soluble electron-shuttle proteins such as cytochrome c and azurin . RESULTS: The crystal structure of the oxidized form of PsCCP has been determined to 2.4 A resolution by multiple isomorphous replacement, and refined to an R-factor of 19.2% . PsCCP is organized into two domains, both of them containing a covalent c-haem in a structure reminiscent of class 1 cytochromes c . The domains are related by a quasi-twofold axis . The domain interface holds a newly discovered calcium-binding site with an unusual set of ligands . CONCLUSIONS: The likely function of the calcium site is to maintain the structural integrity of the enzyme and/or to modulate electron transfer between the two haem domains . The low-potential haem has two histidine axial ligands (His55 and His71) and the high-potential haem is ligated by His201 and Met275 . There are no polar residues at the peroxidatic site in the inactive oxidized enzyme . The structure suggests that, in the half-reduced functional form of the enzyme, the low-potential haem has to shed His71 in order to make the enzyme catalytically competent . This process is likely to trigger a reorganization of the active site, and may introduce a new residues into the haem pocket.

Mol Gen Genet, 1995 Nov 15, 249(2), 217 - 28
Structural genes for salicylate biosynthesis from chorismate in Pseudomonas aeruginosa; Serino L et al.; Salicylate is a precursor of pyochelin in Pseudomonas aeruginosa and both compounds display siderophore activity . To elucidate the salicylate biosynthetic pathway, we have cloned and sequenced a chromosomal region of P . aeruginosa PAO1 containing two adjacent genes, designated pchB and pchA, which are necessary for salicylate formation . The pchA gene encodes a protein of 52 kDa with extensive similarity to the chorismate-utilizing enzymes isochorismate synthase, anthranilate synthase (component I) and p-aminobenzoate synthase (component I), whereas the 11 kDa protein encoded by pchB does not show significant similarity with other proteins . The pchB stop codon overlaps the presumed pchA start codon . Expression of the pchA gene in P . aeruginosa appears to depend on the transcription and translation of the upstream pchB gene . The pchBA genes are the first salicylate biosynthetic genes to be reported . Salicylate formation was demonstrated in an Escherichia coli entC mutant lacking isochorismate synthase when this strain expressed both the pchBA genes, but not when it expressed pchB alone . By contrast, an entB mutant of E . coli blocked in the conversion of isochorismate to 2,3-dihydro-2,3-dihydroxybenzoate formed salicylate when transformed with a pchB expression construct . Salicylate formation could also be demonstrated in vitro when chorismate was incubated with a crude extract of P . aeruginosa containing overproduced PchA and PchB proteins; salicylate and pyruvate were formed in equimolar amounts . Furthermore, salicylate-forming activity could be detected in extracts from a P . aeruginosa pyoverdin-negative mutant when grown under iron limitation, but not with iron excess . Our results are consistent with a pathway leading from chorismate to isochorismate and then to salicylate plus pyruvate, catalyzed consecutively by the iron-repressible PchA and PchB proteins in P . aeruginosa.

Proc Natl Acad Sci U S A, 1995 Nov 7, 92(23), 10762 - 6
Crystal structure of Pseudomonas aeruginosa catabolic ornithine transcarbamoylase at 3.0-A resolution: a different oligomeric organization in the transcarbamoylase family; Villeret V et al.; The crystal structure of the Glu-105-->Gly mutant of catabolic ornithine transcarbamoylase (OTCase; carbamoyl phosphate + L-ornithine = orthophosphate + L-citrulline, EC 2.1.3.3) from Pseudomonas aeruginosa has been determined at 3.0-A resolution . This mutant is blocked in the active R (relaxed) state . The structure was solved by the molecular replacement method, starting from a crude molecular model built from a trimer of the catalytic subunit of another transcarbamoylase, the extensively studied aspartate transcarbamoylase (ATCase) from Escherichia coli . This model was used to generate initial low-resolution phases at 8-A resolution, which were extended to 3-A by noncrystallographic symmetry averaging . Four phase extensions were required to obtain an electron density map of very high quality from which the final model was built . The structure, including 4020 residues, has been refined to 3-A, and the current crystallographic R value is 0.216 . No solvent molecules have been added to the model . The catabolic OTCase is a dodecamer composed of four trimers organized in a tetrahedral manner . Each monomer is composed of two domains . The carbamoyl phosphate binding domain shows a strong structural homology with the equivalent ATCase part . In contrast, the other domain, mainly implicated in the binding of the second substrate (ornithine for OTCase and aspartate for ATCase) is poorly conserved . The quaternary structures of these two allosteric transcarbamoylases are quite divergent: the E . coli ATCase has pseudo-32 point-group symmetry, with six catalytic and six regulatory chains; the catabolic OTCase has 23 point-group symmetry and only catalytic chains . However, both enzymes display homotropic and heterotropic cooperativity.

Prostaglandins, 1995 Nov-Dec, 50(5-6), 301 - 11
Inhibition of the human platelet cyclooxygenase response by the naturally occurring phenazine derivative, 1-hydroxyphenazine; Muller M et al.; The phenazine derivative, 1-hydroxyphenazine (OHP), is produced in vivo by Pseudomonas aeruginosa, an organism that colonises the airways of patients with cystic fibrosis . While known to inhibit leukotriene production by human neutrophils, the effects of OHP on cyclooxygenase pathways have not previously been reported . We used {3H} arachidonic acid (AA) under conditions of concurrent labelling-stimulation or pre-labelling for one hour followed by stimulation to determine the effects of OHP on the production of cyclooxygenase metabolites by human platelets stimulated with the calcium ionophore, A23187 . Thromboxane B2 (TxB2) and 12-hydroxyheptadecatrienoic acid (HHT) production was inhibited in a dose-dependent manner by OHP using either pre-labelled or concurrently labelled platelets . However, production of 12-hydroxyeicosatetraenoic acid (12-HETE) was not diminished . Determination of the amount of total free label (AA+non-esterified AA metabolites) after stimulation of pre-labelled platelets indicated a dose-dependent inhibition of the release of AA from phospholipid by OHP . This was reflected in a corresponding increase in phospholipid AA content . These data indicate that phenazine derivatives of bacterial origin exhibit complex interactions with pathways of arachidonic acid metabolism in host cells . These effects may prove to be of pharmacological importance.

J Ky Med Assoc, 1995 Nov, 93(11), 511 - 3
Pseudomonas pickettii pneumonia in a diabetic patient; Ahkee S et al.; Pseudomonas pickettii is a nonfermenting gram negative rod closely related to Pseudomonas aeruginosa that rarely causes human disease . We describe a case of P pickettii pneumonia in a 41-year-old diabetic patient . Two months prior to admission, patient was treated for a methicillin resistant Staphylococcus aureus pneumonia . Present illness started 2 days prior to admission with fever, chills, pleuritic chest pain, and productive cough . Chest x-ray showed a right lower lobe infiltrate with effusion . Thoracocentesis of the right chest brought a transudative fluid . P picketii was isolated from pleural fluid and blood . The patient was initially treated with aztreonam and piperacillin and therapy was changed to ampicillin according to sensitivity results . The pneumonia resolved after 10 days of antibiotic therapy . Our case is the first reported case of P pickettii pneumonia . P pickettii has been reported to cause nosocomial bacteremias associated with contaminated intravenous products and airway colonization from contaminated respiratory therapy solution . Our patient most likely had oropharyngeal colonization with P pickettii during his previous hospitalization . His underlying illnesses might have predisposed him to aspiration and development of P pickettii pneumonia . This case emphasizes the central role of the microbiology laboratory in the proper identification and sensitivity reporting in the management of respiratory infections caused by unusual organisms, such as P pickettii.

Mol Microbiol, 1995 Nov, 18(3), 547 - 58
Genetic and functional evidence that Type IV pili are required for social gliding motility in Myxococcus xanthus; Wu SS et al.; The social gliding behaviour of Myxococcus xanthus has previously been associated with the presence of polar pili . A Tn5 transposon insertion was isolated which introduces a defect in social gliding and is genetically linked to a known sgl locus; this insertion was found also to cause a piliation defect . A 2.7 kb section of DNA was isolated from either side of this transposon and sequenced, revealing three genes which encode amino acid sequences with substantial similarity to components of the Type IV pilus biogenesis pathway in Pseudomonas aeruginosa . The myxococcal pilA gene encodes a putative pilin precursor with a short signal sequence and processing site similar to those of other Type IV pilins . Myxococcal pilS and pilR encode amino acid sequences with similarity to PilS and PilR of P . aeruginosa, as well as to other members of the NtrB/C family of two-component regulators . Mutations within pilR and pilA that have no polar effect were demonstrated to be responsible for pilus and social motility defects . These results indicate that the pili of M . xanthus belong to the Type IV family of pili, and demonstrate that these pili are actually required for social motility.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1995 Nov, 11(6), 421 - 4
{The effect of different topical agents on pseudomonas infection of burn wound}; Guo Z et al.; 48 Wistar rats were scalded resulting in 15% TBSA full-thickness burn . Pseudomonas aeruginosa (10(9)/ml was inoculated to the wounds . The rats were divided into 6 groups . 5 different topical agents were separately applied to the wounds constituting 5 groups, and no drug was used in control group . Through observing the appearance of wound, the quantity of bacteria in the subeschar tissue and histo-pathological changes, we confirmed that AgSD-ZnSD-A cream was a satisfactory topical agent.

Genetika, 1995 Nov, 31(11), 1507 - 11
{Cryptic transposable phages of Pseudomonas aeruginosa}; Krylov VN et al.; Frequencies of nucleotide sequences homologous to phage transposons (PT) of two species, D3112 and B3, were assessed in genomes of natural Pseudomonas aeruginosa strains by the dot-blot hybridization method . These strains were incapable of liberating viable phages on a lawn of the PA01 standard indicator strain of P . aeruginosa . It was shown that the homologies detected belong to two groups, high and intermediate, with respect to homology level . Homology patterns were classified as high when they provided signals comparable to those for hybridization in a positive control; they were classified as intermediate when the hybridization level higher than the background level, but lower than in the positive control . Homologous PT sequences were designated as cryptic PT . Intact cryptic PT prophages were shown to exist in genomes of particular natural strains manifesting a high level of hybridization . However, the growth of these phages was limited by the restriction system of strain PA01 . It is possible to isolate strains maintaining the growth of a portion of cryptic PT . These strains differed from P . aeruginosa with respect to the specificity of the restriction and modification system . Nevertheless, in most cases, the attempt to identify a novel host capable of maintaining growth of a cryptic PT failed . Natural strains often carry cryptic PT related to both known PT species, D3112 and B3 . The frequency of cryptic PT is extremely high, reaching 30% in only strains with a high level of homology and up to 50% in all strains exhibiting homology . This high PT frequency is assumed to be associated with the considerable variation of P . aeruginosa.

Eur J Clin Microbiol Infect Dis, 1995 Nov, 14(11), 979 - 86
Lack of additive effect between mechanisms of resistance to carbapenems and other beta-lactam agents in Pseudomonas aeruginosa; Dib C et al.; Eighty-nine clinical isolates resistant (n = 61) or susceptible (n = 28) to imipenem and exhibiting the main patterns of susceptibility to other beta-lactam agents (wild type pattern, penicillinase pattern, constitutive cephalosporinase pattern) were studied in order to investigate (i) the mechanism of resistance involved and (ii) whether resistance to carbapenems affects the level of resistance to other beta-lactam agents and, conversely, if resistance to other beta-lactam agents affects the level of resistance to carbapenems . For this purpose, the presence of OprD protein in the cell wall was detected by Western blot and beta-lactamase activity by spectrophotometric assay and isoelectric focusing . OprD expression was not detectable in the imipenem-resistant (MIC > or = 16 micrograms/ml) strains . It was decreased in half the strains for which MICs of imipenem were 2 to 8 micrograms/ml and was close to a normal level in the most susceptible strains (MIC < or = 1 microgram/ml), thus demonstrating a direct correlation between the level of susceptibility to imipenem and the level of OprD expression . No imipenemase activity was detected in imipenem-resistant strains . Synergy between imipenem or meropenem and BRL 42715 was observed for all of the strains, demonstrating the role of cephalosporinase in carbapenem resistance . Within each pattern of susceptibility, the mean MICs of beta-lactam agents other than carbapenems were similar, whether the strains were susceptible or resistant to imipenem . Conversely, the mean MICs of imipenem or meropenem for either the imipenem-resistant or the imipenem-susceptible strains were similar, regardless of the susceptibility of these strains to the other beta-lactam agents . Thus, when several mechanisms of resistance to beta-lactam agents are present in the same strain of Pseudomonas aeruginosa, there is no additive effect between these mechanisms.

Eur J Clin Microbiol Infect Dis, 1995 Nov, 14(11), 964 - 71
Emergence of resistance to beta-lactam agents in Pseudomonas aeruginosa with group I beta-lactamases in Spain; Colom K et al.; The contribution of induction and stable derepression of chromosomal class I beta-lactamases to beta-lactam antibiotic resistance was studied in clinical isolates of Pseudomonas aeruginosa collected from patients treated with beta-lactam antibiotics . Multiple isolates from the same patient were characterized by O-serotyping as a primary screen, combined with pyocin typing . Sonicated extracts of cells were assayed for chromosomal and plasmid-mediated beta-lactamases by isoelectric focusing and cloxacillin inhibition studies . The specific beta-lactamase activity, basal and induced, with cefoxitin was determined to differentiate strains with inducible or derepressed production of the enzyme . Beta-lactamase induction was performed in each strain against the beta-lactam agents used in the therapy of each patient . The observations showed that induction against older penicillins such as penicillin, amoxicillin, and amoxicillin/clavulanate resulted in a moderate to strong increase in beta-lactamase activity, whereas the results obtained with first-generation cephalosporins varied with the beta-lactam agent tested . Third-generation cephalosporins were weak inducers of beta-lactamases, and their use as therapy preceded the appearance of strains that produce chromosomal group I beta-lactamases constitutively . These strains showed a remarkable reduction in sensitivity to ureidopenicillins, carboxipenicillins, third-generation cephalosporins, and monobactams, but not to carbapenems.

Pediatr Cardiol, 1995 Nov-Dec, 16(6), 294 - 6
Fatal pneumonia complicating hypothermia for the treatment of postoperative junctional ectopic tachycardia; Matthys D et al.; A 5-month-old male infant developed junctional ectopic tachycardia after surgical repair for ventricular septal defect . Management with sotalol and moderate hypothermia was initially successful, but he died from Pseudomonas aeruginosa pneumonia . The safety of treatment with hypothermia is discussed.

J Antimicrob Chemother, 1995 Nov, 36(5), 827 - 31
Inhibition of Helicobacter pylori growth by 4-hydroxy-2-alkyl-quinolines produced by Pseudomonas aeruginosa; Lacey SL et al.; 4-Hydroxy-2-alkylquinolines produced by Pseudomonas aeruginosa can inhibit the growth of both metronidazole-sensitive and resistant strains of Helicobacter pylori in vitro . The MIC of one analogue, 4-hydroxy-2-heptylquinoline, was determined by agar plate incorporation as 0.1-0.5 mg/L which compares favourably with other anti-helicobacter agents.

Shock, 1995 Nov, 4(5), 345 - 50
Caco-2 and IEC-18 intestinal epithelial cells exert bactericidal activity through an oxidant-dependent pathway; Deitch EA et al.; Intestinal epithelial cells have receptors that recognize bacterial antigens and in some circumstances are actively involved in bacterial internalization . To test the hypothesis that intestinal epithelial cells possess bactericidal capabilities, the bactericidal activity of two intestinal cell lines (IEC-18 and Caco-2) was measured using Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli as test organisms . The relative bactericidal efficacy of these two intestinal cell lines to kill these bacteria was compared against neutrophils (PMN) using a standard in vitro bactericidal assay . The IEC-18 and Caco-2 cells as well as the PMNs killed S . aureus and P . aeruginosa but not E . coli (p < .05) . In fact, when tested in serum-free medium, the IEC-18 and Caco-2 cells killed a greater percentage of bacteria than the PMNs (p < .05) . The addition of the antioxidant, superoxide dismutase, significantly reversed the bactericidal activity of both Caco-2 cells and neutrophils for P . aeruginosa and S . aureus, while catalase had no effect . Nitric oxide inhibition by NG-nitro-L-arginine methyl ester (L-NAME) had no effect on bactericidal activity of Caco-2 cells . These results indicate that intestinal epithelial cells can kill certain strains of bacteria and may function as "nonprofessional" phagocytes . Additionally, the mechanisms involved in the killing of P . aeruginosa and S . aureus by the Caco-2 and IEC-18 cells appear similar to the PMNs to the extent that bactericidal activity appeared to be oxidant-mediated but not nitric oxide-mediated in both the Caco-2 cell line and in the neutrophils.

Antimicrob Agents Chemother, 1995 Nov, 39(11), 2567 - 9
The outer membrane protein OprM of Pseudomonas aeruginosa is encoded by oprK of the mexA-mexB-oprK multidrug resistance operon; Gotoh N et al.; An outer membrane protein (OprK) overproduced in a multiply antibiotic-resistant strain of Pseudomonas aeruginosa was previously identified as the product of the third gene of a multidrug resistance operon, mexA-mexB-oprK (K . Poole, K . Krebes, C . McNally, and S . Neshat, J . Bacteriol . 175:7363-7372, 1993) . To determine whether this protein was identical to another outer membrane protein (OprM) also overproduced in some multiply resistant strains, attempts were made to map the transposon insertion site of several OprM-deficient mutants to the mex operon . Amplification of chromosomal DNA of several Tn5 insertion OprM-deficient mutants with primers specific to each gene of the mex operon revealed that the transposon had inserted into mexB in one instance and into oprK in two others . Furthermore, introduction of the cloned mexA-mexB-oprK operon into these mutants restored expression of multidrug resistance, concomitant with OprM production . These data demonstrated that OprM is encoded by the mex operon . OprM and OprK were not, however, immunologically cross-reactive, indicating that they are distinct proteins and that OprK is, in fact, not encoded by the mex operon . This operon is thus renamed mexA-mexB-oprM.

Antimicrob Agents Chemother, 1995 Nov, 39(11), 2503 - 10
Comparison of the bactericidal activities of ofloxacin and ciprofloxacin alone and in combination with ceftazidime and piperacillin against clinical strains of Pseudomonas aeruginosa; Klepser ME et al.; On the basis of MIC data, ciprofloxacin exhibits superior activity against Pseudomonas aeruginosa than the other currently available fluoroquinolones do . Despite the antipseudomonal advantage noted for ciprofloxacin monotherapy, it is unknown whether this advantage is maintained when the fluoroquinolones are used in combination with antipseudomonal beta-lactams such as ceftazidime and piperacillin . Twelve healthy volunteers were enrolled in this open-label, randomized, steady-state, six-way cross-over, comparative trial . All subjects received the following regimens: (i) 400 mg of ofloxacin given intravenously (i.v.) every 12 h (q12h), (ii) 400 mg of ciprofloxacin given i.v . q12h, (iii) 400 mg of ofloxacin given i.v . q12h plus 1 g of ceftazidime given i.v . every 8 h (q8h), (iv) 400 mg of ciprofloxacin given i.v . q12h plus 1 g of ceftazidime given i.v . q8h, (v) 400 mg of ofloxacin given i.v . q12h plus 4 g of piperacillin given i.v . q8h, and (vi) 400 mg of ciprofloxacin given i.v . q12h plus 4 g of piperacillin given i.v . q8h . Serum bactericidal titers with subsequent calculation of the area under the bactericidal curve were determined against three clinical isolates of P . aeruginosa . As monotherapy, ciprofloxacin demonstrated superior antipseudomonal activity than ofloxacin did; however, combination of these agents with ceftazidime yielded remarkably similar and statistically comparable activity profiles . In contrast, ciprofloxacin-piperacillin retained a bactericidal advantage over ofloxacin-piperacillin . Although ciprofloxacin exhibits superior antipseudomonal activity when used as monotherapy, combination of ofloxacin or ciprofloxacin with ceftazidime yielded equivalent activity profiles against susceptible strains of P . aeruginosa.

Antimicrob Agents Chemother, 1995 Nov, 39(11), 2423 - 5
Treatment of Pseudomonas aeruginosa-infected orthopedic prostheses with ceftazidime-ciprofloxacin antibiotic combination; Brouqui P et al.; Indwelling device infections are associated with considerable morbidity and extremely high cost . Pseudomonas aeruginosa is the most frequent gram-negative etiologic agent associated with infections of indwelling catheters and foreign body implants . It is generally agreed that eradication of infection in the presence of a foreign body requires removal of the foreign body . Using a combination of ceftazidime and ciprofloxacin, we cured nine of nine patients with P . aeruginosa-infected osteosynthetic material and four of five patients with hip and knee prostheses without removing the foreign material . Follow-up was for a mean of 21 months (range, 6 to 60 months) . Some patients experienced minor side effects (arthralgia in one patient and rash in another patient) . We conclude that this combination is effective and safe and should be useful in the treatment of P . aeruginosa-infected orthopedic implants.

Antimicrob Agents Chemother, 1995 Nov, 39(11), 2411 - 4
Routine susceptibility testing of four antibiotic combinations for improvement of laboratory guide to therapy of cystic fibrosis infections caused by Pseudomonas aeruginosa; Weiss K et al.; Previous studies have demonstrated synergy between an aminoglycoside and a beta-lactam for treating Pseudomonas aeruginosa infections . Cystic fibrosis patients are prone to infection by this bacterium, which becomes very resistant with recurrent antibiotic treatments . The purpose of this study was to evaluate the susceptibility patterns of 122 isolates of P . aeruginosa isolated from cystic fibrosis patients to five individual antibiotics (tobramycin, ceftazidime, piperacillin, ticarcillin, and imipenem) and to four antibiotic combinations (tobramycin associated with one of the other antibiotics) . Strains were selected because of their resistance to individual antimicrobial agents, which ranged from 21.3% for imipenem to 56.5% for tobramycin . By using an automated broth microdilution method, we were able to demonstrate synergy against 39 strains (32%) with tobramycin-ticarcillin, against 38 strains (31%) with tobramycin-piperacillin, against 47 strains (39%) with tobramycin-ceftazidime, and against 23 strains (19%) with tobramycin-imipenem . Of the 122 isolates, 77 (63%) were rendered significantly susceptible to at least one of the four antibiotic combinations by synergy . These results suggest that when appropriate technology is available, susceptibility to antibiotic combinations greatly improves the guide to antibiotic therapy for infections due to P . aeruginosa in cystic fibrosis patients.

Antimicrob Agents Chemother, 1995 Nov, 39(11), 2392 - 6
OprK and OprM define two genetically distinct multidrug efflux systems in Pseudomonas aeruginosa; Hamzehpour MM et al.; Multidrug-resistant derivatives of Pseudomonas aeruginosa PAO1 were obtained after stepwise selection on tetracycline or erythromycin . Two phenotypes were generated . The tetracycline-resistant mutant (TETR) was phenotypically similar to OprM-overexpressing strains . This group displayed cross-resistance to quinolones, chloramphenicol, and all beta-lactams tested except imipenem, with no changes in the erythromycin MICs for the strains . Sodium dodecyl sulfate-polyacrylamide gels showed the overproduction of an outer membrane protein in the range of 50 kDa and a 46-kDa inner membrane protein . The erythromycin-resistant mutant (ERYR) kept its susceptibility to all beta-lactams tested with the exception of cefpirome, but it was resistant to chloramphenicol, quinolones, and tetracycline and was hypersusceptible to imipenem . This mutant also exhibited overexpression of a 50-kDa outer membrane protein that was different from OprM and of a 43-kDa inner membrane protein . The phenotype of ERYR was comparable to those of OprK- and OprJ-overexpressing strains . These strains were therefore classified as the OprK-like group . Transduction of the oprK::omega-Hg mutation of strain K613 (K . Poole, K . Krebes, C . McNally, and S . Neshat, J . Bacteriol . 175:7363-7372, 1993) into the multidrug-resistant strains resulted in the loss of multidrug resistance and the acquisition of hypersusceptibility in the OprM group, while the phenotype of the OprK-like group was unaffected . These experiments demonstrated the existence of two genetically distinct efflux systems in P . aeruginosa . The identities of the operons encoding the two efflux systems and their physiological roles are discussed.

Clin Diagn Lab Immunol, 1995 Nov, 2(6), 747 - 52
Identification of outer membrane proteins as target antigens of Pseudomonas aeruginosa Homma serotype M; Yokota S; Pseudomonas aeruginosa is routinely serotyped in Japan by using the Homma scheme . The serotypes (O serotypes) are based on the chemical structure of the O-polysaccharide portion of the lipopolysaccharide (LPS) . However, the nature of the Homma serotype M antigen has remained obscure because strains classified as serotype M usually have the rough phenotype . I characterized the target antigen of serotype M . The results of Western blotting (immunoblotting) showed that commercially available typing monoclonal antibody (MAb) against serotype M specifically bound to outer membrane protein (Opr) G and that typing rabbit antiserum specific for serotype M mainly contained antibodies against Oprs F and H2 . These Oprs were distributed among all P . aeruginosa strains tested, including the serotype standard, serotype M and nontypeable strains, and a series of LPS-core-defective mutants derived from strain PAC1 . However, the rough mutants derived from strain PAC1 agglutinated with the anti-serotype M antibodies, whereas the smooth strains did not . LPS preparations from serotype M strains possessed few or no polysaccharide chains . These strains had higher levels of binding activity with anti-serotype M MAb, as well as with anti-lipid A MAb, which specifically bound to the cell surface of the rough-natured gram-negative bacterial strains with high activity . The anti-serotype M antiserum also contained rough-LPS-specific antibodies, but the epitope was distributed among only a few strains . The results suggested that the Oprs acted as the serotype M antigen and that LPS did not . In conclusion, the rough strains agglutinated with anti-Opr antibodies and were distinguished as serotype M from the smooth strains of other serotypes, because the antibodies were accessible to the cell surface lacking O polysaccharides . I supposed that Homma serotype M is an index of the rough nature of P . aeruginosa strains rather than one of the O serotypes.

Biosci Biotechnol Biochem, 1995 Nov, 59(11), 2178 - 80
Optical resolution of 1-arylethanols with a condensed aromatic ring by lipase from Pseudomonas aeruginosa; Kato K et al.; Enantioselective syntheses of both enantiomers of 1-arylethanols with a condensed aromatic ring have been done through acetylation of the racemic alcohols with vinyl acetate in the presence of a lipase from Pseudomonas aeruginosa (Toyobo, LIP) . The lipase LIP showed high enantioselectivity and reactivity for the title compounds, reacted acetates, and remaining alcohols were obtained with high optical purity.

Br J Ophthalmol, 1995 Nov, 79(11), 1024 - 8
Causes of suppurative keratitis in Ghana; Hagan M et al.; AIMS--Suppurative keratitis is a serious problem in all tropical countries, but very little information is available about the causative organisms in Africa . The objectives were to identify the causative organisms and the proportion of cases caused by fungi in southern Ghana, and to determine whether correct decisions about treatment could be made on the basis of Gram stain in the eye clinic . METHODS--Scrapings were taken from corneal ulcers of consecutive new patients presenting at Korle Bu Hospital, Accra, and inoculated on 'chocolate' and Sabouraud's agars . Further scrapings were taken for Gram staining and interpretation in the eye clinic . Duplicate slides were assessed by an experienced microbiologist in the UK . RESULTS--One or more organisms were cultured from 114 of 199 patients (57.3%), the most common being Fusarium species, Pseudomonas aeruginosa, and Staphylococcus epidermidis . Fungi, alone or in combination, were isolated from 56% of the patients who had positive cultures . In total, 122 patients (61.3%) had their treatment either determined or altered based on the results of the microbiological diagnosis; in 87 of these solely on the basis of direct microscopic examination . CONCLUSIONS--Infection by filamentous fungi accounted for more than half of the ulcers from which cultures were obtained . Both training in technique and experience in interpretation are necessary for microscopy based diagnosis by staff in the clinic to be of greatest value . Direct microscopy was particularly useful for detecting fungi.

Chemotherapy, 1995 Nov-Dec, 41(6), 462 - 9
The administration regimen of isepamicin in patients with chronic respiratory tract infection; Hara K et al.; A total of 34 patients with intractable chronic respiratory tract infections were treated with isepamicin and/or piperacillin in different dosage regimens . A comparison of the bacteriological effect using a cross over method showed a reduction in the count of Pseudomonas aeruginosa in sputum in the group receiving once-a-day isepamicin combined with piperacillin, compared with the twice-a-day combined administration . A comparison of the clinical and bacteriological efficacy between the different regimen groups revealed no noticeable difference . The clinical effect of this regimen is comparable to the conventional regimen, but has the advantages of a safer dosage and ease of administration.

Chemotherapy, 1995 Nov-Dec, 41(6), 433 - 6
Postantibiotic effect of imipenem, alone and in combination with amikacin, on Pseudomonas aeruginosa; Gerceker AA et al.; Imipenem and amikacin, alone and in combination, were investigated for their postantibiotic effect (PAE) on Pseudomonas aeruginosa . Four clinical strains of P . aeruginosa in the logarithmic phase of growth were exposed for 1 h to antibiotics, alone and in combination . Recovery periods of test cultures were evaluated after dilution using viable counting . Imipenem produced a PAE ranging from 0.7 to 1.55 h . Similar PAEs were induced by amikacin (ranging from 0.65 to 2 h) . In combination, imipenem and amikacin produced as a final PAE (ranging from 1.6 to 2.65 h), a rough mathematical sum of the individual effects . The finding of this study may have important implications for the timing of doses during therapy with antimicrobial combinations.

J Am Acad Dermatol, 1995 Nov, 33(5 Pt 2), 857 - 64
Wells' syndrome in childhood: case report and review of the literature; Anderson CR et al.; We report a severe case of Wells' syndrome, or eosinophilic cellulitis, after a bee sting in a 4-year-old girl . The patient had a widespread, painful, blistering eruption that was subsequently complicated by Pseudomonas aeruginosa superinfection and septicemia, hypoalbuminemia, anemia, and neutropenia . The skin lesions responded to systemic steroid therapy . There was residual scarring alopecia of the scalp . There have been 17 previous reports of childhood Wells' syndrome . We believe that this disorder is a distinct entity that should be considered in the differential diagnosis of blistering diseases in children.

J Clin Invest, 1995 Nov, 96(5), 2204 - 10
Diverse Pseudomonas aeruginosa gene products stimulate respiratory epithelial cells to produce interleukin-8; DiMango E et al.; Respiratory epithelial cells play a crucial role in the inflammatory response during Pseudomonas aeruginosa infection in the lungs of patients with cystic fibrosis . In this study, we determined whether the binding of specific Pseudomonas gene products (pilin, flagellin) to their receptors on respiratory epithelial cells would result in production of the neutrophil chemoattractant IL-8 . Piliated wild-type organisms, purified pili, or antibody to the pilin receptor (asialoGM1) evoked significant production of IL-8 by immortalized airway epithelial cells, whereas nonpiliated organisms were less able to bind to respiratory epithelial cells and stimulated much less IL-8 secretion (P < 0.01) . A piliated, nonflagellated strain was also associated with decreased binding and a diminished level of IL-8 production when compared to wild-type organisms . Isogenic, nonadherent rpoN mutants, lacking pilin and flagellin, did not bind or elicit an IL-8 response . In addition, the IL-8 response was four-fold higher in a cystic fibrosis cell line compared with its corrected cell line . The Pseudomonas autoinducer, an exoproduct secreted during chronic infection, was found to stimulate IL-8 in a dose-dependent manner . P . aeruginosa adhesins, which are necessary for initial infection, directly stimulate IL-8 production by respiratory epithelial cells and therefore play a major role in the pathogenesis of Pseudomonas infection in patients with cystic fibrosis . The inflammatory response is subsequently perpetuated by Pseudomonas autoinducer which is secreted during chronic infection.

J Bacteriol, 1995 Nov, 177(22), 6536 - 44
Cloning and characterization of the katB gene of Pseudomonas aeruginosa encoding a hydrogen peroxide-inducible catalase: purification of KatB, cellular localization, and demonstration that it is essential for optimal resistance to hydrogen peroxide; Brown SM et al.; Pseudomonas aeruginosa is an obligate aerobe that is virtually ubiquitous in the environment . During aerobic respiration, the metabolism of dioxygen can lead to the production of reactive oxygen intermediates, one of which includes hydrogen peroxide . To counteract the potentially toxic effects of this compound, P . aeruginosa possesses two heme-containing catalases which detoxify hydrogen peroxide . In this study, we have cloned katB, encoding one catalase gene of P . aeruginosa . The gene was cloned on a 5.4-kb EcoRI fragment and is composed of 1,539 bp, encoding 513 amino acids . The amino acid sequence of the P . aeruginosa katB was approximately 65% identical to that of a catalase from a related species, Pseudomonas syringae . The katB gene was mapped to the 71- to 75-min region of the P . aeruginosa chromosome, the identical region which harbors both sodA and sodB genes encoding both manganese and iron superoxide dismutases . When cloned into a catalase-deficient mutant of Escherichia coli (UM255), the recombinant P . aeruginosa KatB was expressed (229 U/mg) and afforded this strain resistance to hydrogen peroxide nearly equivalent to that of the wild-type E . coli strain (HB101) . The KatB protein was purified to homogeneity and determined to be a tetramer of approximately 228 kDa, which was in good agreement with the predicted protein size derived from the translated katB gene . Interestingly, KatB was not produced during the normal P . aeruginosa growth cycle, and catalase activity was greater in nonmucoid than in mucoid, alginate-producing organisms . When exposed to hydrogen peroxide and, to a greater extent, paraquat, total catalase activity was elevated 7- to 16-fold, respectively . In addition, an increase in KatB activity caused a marked increase in resistance to hydrogen peroxide . KatB was localized to the cytoplasm, while KatA, the "housekeeping" enzyme, was detected in both cytoplasmic and periplasmic extracts . A P . aeruginosa katB mutant demonstrated 50% greater sensitivity to hydrogen peroxide than wild-type bacteria, suggesting that KatB is essential for optimal resistance of P . aeroginosa to exogenous hydrogen peroxide.

J Bacteriol, 1995 Nov, 177(22), 6330 - 7
Pseudomonas aeruginosa sodA and sodB mutants defective in manganese- and iron-cofactored superoxide dismutase activity demonstrate the importance of the iron-cofactored form in aerobic metabolism; Hassett DJ et al.; The consumption of molecular oxygen by Pseudomonas aeruginosa can lead to the production of reduced oxygen species, including superoxide, hydrogen peroxide, and the hydroxyl radical . As a first line of defense against potentially toxic levels of endogenous superoxide, P . aeruginosa possesses an iron- and manganese-cofactored superoxide dismutase (SOD) to limit the damage evoked by this radical . In this study, we have generated mutants which possess an interrupted sodA (encoding manganese SOD) or sodB (encoding iron SOD) gene and a sodA sodB double mutant . Mutagenesis of sodA did not significantly alter the aerobic growth rate in rich medium (Luria broth) or in glucose minimal medium in comparison with that of wild-type bacteria . In addition, total SOD activity in the sodA mutant was decreased only 15% relative to that of wild-type bacteria . In contrast, sodB mutants grew much more slowly than the sodA mutant or wild-type bacteria in both media, and sodB mutants possessed only 13% of the SOD activity of wild-type bacteria . There was also a progressive decrease in catalase activity in each of the mutants, with the sodA sodB double mutant possessing only 40% of the activity of wild-type bacteria . The sodA sodB double mutant grew very slowly in rich medium and required approximately 48 h to attain saturated growth in minimal medium . There was no difference in growth of either strain under anaerobic conditions . Accordingly, the sodB but not the sodA mutant demonstrated marked sensitivity to paraquat, a superoxide-generating agent . P . aeuroginosa synthesizes a blue, superoxide-generating antibiotic similar to paraquat in redox properties which is called pyocyanin, the synthesis of which is accompanied by increased iron SOD and catalase activities (D.J . Hassett, L . Charniga, K . A . Bean, D . E . Ohman, and M . S . Cohen, Infect . Immun . 60:328-336, 1992) . Pyocyanin production was completely abolished in the sodB and sodA sodB mutants and was decreased approximately 57% in sodA mutants relative to that of the wild-type organism . Furthermore, the addition of sublethal concentrations of paraquat to wild-type bacteria caused a concentration-dependent decrease in pyocyanin production, suggesting that part of the pyocyanin biosynthetic cascade is inhibited by superoxide . These results suggest that iron SOD is more important than manganese SOD for aerobic growth, resistance to paraquat, and optimal pyocyanin biosynthesis in P . aeruginosa.

Infect Immun, 1995 Nov, 63(11), 4519 - 23
Nonopsonic phagocytosis of Pseudomonas aeruginosa by macrophages and polymorphonuclear leukocytes requires the presence of the bacterial flagellum; Mahenthiralingam E et al.; Whereas the mechanism of nonopsonic phagocytosis of Pseudomonas aeruginosa has been described, the bacterial ligands required are poorly understood . To identify the requisite bacterial ligands, studies with isogenic mutants of P . aeruginosa PAK lacking pili, flagella, and the RpoN sigma factor were undertaken . The RpoN mutant, lacking pili, flagella, and nonpilus adhesins, bound poorly and was resistant to ingestion by both macrophages and neutrophils . Pili were not absolutely required for binding or phagocytosis of P . aeruginosa . The presence of a flagellum was not required for binding of P . aeruginosa to macrophages but was critical for the subsequent internalization of the bacterium, suggesting that this factor or a surface ligand associated with its assembly was responsible for stimulation of nonopsonic phagocytosis.

Infect Immun, 1995 Nov, 63(11), 4481 - 8
Functional properties of isotype-switched immunoglobulin M (IgM) and IgG monoclonal antibodies to Pseudomonas aeruginosa lipopolysaccharide; Pollack M et al.; Controversy exists regarding isotype-related differences in the antibacterial and protective properties of lipopolysaccharide (LPS)-specific antibodies of the immunoglobulin M (IgM) class and various IgG subclasses . To clarify this issue, a murine hybridoma secreting IgM monoclonal antibody (MAb) specific for the O polysaccharide of Pseudomonas aeruginosa serogroup O6 LPS was class switched, by sib selection, to produce an IgG3 MAb with identical specificity and variable region heavy and light chain nucleotide sequences . This IgG3-secreting cell line was further switched to the production of O-specific, variable region-identical IgG1, IgG2b, and IgG2a MAbs . Functional comparisons of these LPS-specific IgM and IgG MAb isotypes revealed similar LPS binding, opsonic, and protective activities . Relatively minor isotype-related differences in levels of efficiency of MAb-mediated, complement-dependent opsonophagocytic killing (IgM > IgG2a > IgG3 > IgG2b > > IgG1) were not associated with corresponding differences in in vivo functions . These findings, in conjunction with previously published data, support a cautious approach to generic conclusions regarding the immunotherapeutic superiority of LPS-specific antibodies belonging to either the IgM or IgG class or to a particular IgG subclass.

Infect Immun, 1995 Nov, 63(11), 4301 - 6
A species-specific nucleotide sequence of Mycobacterium tuberculosis encodes a protein that exhibits hemolytic activity when expressed in Escherichia coli; Leao SC et al.; Species-specific proteins may be implicated in the unique pathogenic mechanisms characteristic of Mycobacterium tuberculosis . In previous studies, a 3.0-kb species-specific DNA fragment of M . tuberculosis was identified (C . A . Parra, L . P . Londono, P . del Portillo, and M . E . Patarroyo, Immun . 59:3411-3417, 1991) . The nucleotide sequence of this 3.0-kb fragment has been obtained . This sequence was shown to contain two open reading frames (ORFs) whose putative gene products share 68.9% identity between each other . The major ORF shows 57.8% similarity with PLC-N and 53.2% similarity with PLC-H, two phospholipase C enzymes from Pseudomonas aeruginosa . The major ORF was amplified by PCR and cloned into the pGEX-5T expression vector . Cell extracts of Escherichia coli overexpressing this glutathione S-transferase fusion protein were shown to produce beta-hemolysis suggestive of phospholipase activity . Since phospholipase C enzymes have been reported as virulence factors of P . aeruginosa and also of the intracellular pathogen Listeria monocytogenes, it is possible that the proteins identified in this study could also play a role in sustaining tuberculosis infection in humans.

Curr Microbiol, 1995 Nov, 31(5), 279 - 86
Use of synthetic peptides to identify surface-exposed, linear B-cell epitopes within outer membrane protein F of Pseudomonas aeruginosa; Gilleland HE Jr et al.; In a previous study (Hughes EE, Gilleland LB, Gilleland HE Jr . {1992} Infect Immun 60:3497-3503), ten synthetic peptides were used to test for surface-exposed antigenic regions located throughout the length of outer membrane protein F of Pseudomonas aeruginosa . An additional nine peptides of 11-21 amino acid residues in length were synthesized . Antisera collected from mice immunized with each of the 19 synthetic peptides conjugated to keyhole limpet hemocyanin were used to determine which of the peptides had elicited antibodies capable of reacting with the surface of whole cells of the various heterologous Fisher-Devlin immunotypes of P . aeruginosa . Cell surface reactivity was measured by an enzyme-linked immunosorbent assay (ELISA) with whole cells of the various immunotypes as the ELISA antigens and by opsonophagocytic uptake assays with the various peptide-directed antisera, immunotype 2 P . aeruginosa cells, and polymorphonuclear leukocytes of human and murine origin . Three peptides located in the carboxy-terminal portion of protein F elicited antibodies with the greatest cell-surface reactivity . Peptide 9 (TDAYNQKLSERRAN), peptide 10 (NATAEGRAINRRVE), and peptide 18 (NEYGVEGGRVNAVG) appear to have sufficient potential for further development as vaccine candidates for immunoprophylaxis against infections caused by P . aeruginosa . A topological model for the arrangement of protein F within the outer membrane of P . aeruginosa is presented.

Am J Respir Cell Mol Biol, 1995 Nov, 13(5), 570 - 7
Role of recruited neutrophils in interleukin-8 production in dog trachea after stimulation with Pseudomonas in vivo; Inoue H et al.; Cell-free supernatant of Pseudomonas aeruginosa (PA) recruits neutrophils into the airways indirectly by inducing the production of chemotactic factors, including interleukin-8 (IL-8) . PA products stimulate IL-8 expression selectively in surface airway epithelium, gland ducts, serous cells, and recruited neutrophils . To examine the relative contribution of neutrophils in IL-8 release in the airway lumen, we studied the effect of inhibition of neutrophil recruitment on IL-8 concentration in tracheal fluid after introduction of PA supernatant into the dog trachea in vivo . Tracheal superfusion with PA supernatant caused neutrophil recruitment and increased the IL-8 concentration in the tracheal lumen; NPC 15669 inhibited both effects . To study whether migration of neutrophils into the airway lumen per se induces their expression of IL-8, we compared effects of local introduction of IL-8 and of PA supernatant into the trachea on IL-8 expression in neutrophils recruited into the trachea . PA supernatant, but not exogenous IL-8 alone, induced IL-8 mRNA expression in neutrophils recruited into the trachea . To determine what product(s) of PA stimulate IL-8 expression in neutrophils, we examined neutrophils isolated from peripheral blood . PA supernatant induced IL-8 production in neutrophils, an effect reproduced by PA lipopolysaccharide and inhibited by polymyxin B . These results suggest that neutrophils recruited into the airway lumen play a major role in local IL-8 production in airways in response to bacteria such as PA, depending on the presence of stimuli such as lipopolysaccharide.

Can J Microbiol, 1995 Nov, 41(11), 984 - 91
Pseudomonas aeruginosa strain MA01 aerobically metabolizes the aminodinitrotoluenes produced by 2,4,6-trinitrotoluene nitro group reduction; Alvarez MA et al.; Many microbes reduce the nitro substituents of 2,4,6-trinitrotoluene (TNT), producing aminodinitrotoluenes (ADNTs) . These compounds are recalcitrant to further breakdown and are acutely toxic . In a search for organisms capable of metabolizing ADNTs, a bacterial strain was isolated for the ability to use 2-aminobenzoate (anthranilate) as sole C-source . This isolate, Pseudomonas aeruginosa MA01, metabolized TNT by first reducing one nitro group to form either 2-amino-4,6-dinitrotoluene (2ADNT) or 4-amino-2,6-dinitrotoluene (4ADNT) . However, strain MA01 was distinct from other TNT-reducing organisms in that it transformed these compounds into highly polar metabolites through an O2-dependent process . Strain MA01 was able to cometabolize TNT, 2ADNT, and 4ADNT in the presence of a variety of carbon and energy sources . During aerobic cometabolism with succinate, 45% of uniformly ring-labeled {14C}TNT was transformed to highly polar compounds . Aerobic cometabolism of purified {14C}2ADNT and {14C}4ADNT with succinate as C-source produced similar amounts of these polar metabolites . During O2-limited cometabolism with succinate as C-source and nitrate as electron acceptor, less than 8% of the {14C}TNT was transformed to polar metabolites . Purified 2,6-diamino-4-nitrotoluene was not metabolized, and while 2,4-diamino-6-nitrotoluene was acetylated, the product (N-acetyl-2,4-diamino-6-nitrotoluene) was not further metabolized . Therefore, strain MA01 metabolized TNT by oxidation of the ADNTs and not by reduction the remaining nitro groups on the ADNTs.

Arch Surg, 1995 Nov, 130(11), 1199 - 208
Sepsis-induced acute lung injury is attenuated by selectin blockade following the onset of sepsis; Ridings PC et al.; OBJECTIVE: To determine the effect of infusion with a dual-binding antibody to E- and L-selectin, EL-246, in a postonset model of sepsis . DESIGN: Nonrandomized controlled study . STUDY SUBJECTS: Young Yorkshire swine . INTERVENTIONS: Three groups were studied . Controls (n = 8) received saline solution only . Untreated animals with sepsis (n = 8) received a 1-hour intravenous infusion of live Pseudomonas aeruginosa . Animals treated with EL-246 (n = 6) received the same bacterial infusion and a 2-mg/kg bolus of EL-246 at 30 minutes . OUTCOME MEASURES: Systemic and pulmonary hemodynamics, arterial blood gas determination, bronchoalveolar lavage protein and neutrophil content, neutrophil integrin and selectin expression, neutrophil oxidant burst, and organ myeloperoxidase content . RESULTS: Treatment with EL-246 significantly reduced lung injury, as indicated by improved bronchoalveolar lavage protein and neutrophil content, resulting in a significant improvement in arterial oxygenation . This reduction in lung injury was produced by a reduction in lung myeloperoxidase content . Treatment with EL-246 failed to prevent the development of pulmonary hypertension and systemic hypotension . Neutrophils from animals with sepsis exhibited significant activation and upregulation of CD18, shedding of L-selectin, and production of increased levels of oxidants compared with controls . CONCLUSION: Treatment of animals with EL-246 soon the onset of sepsis produced significant protection against acute lung injury but failed to attenuate hemodynamic derangements associated with sepsis.

J Pediatr, 1995 Nov, 127(5), 711 - 7
Effect of high-affinity anti-Pseudomonas aeruginosa lipopolysaccharide antibodies induced by immunization on the rate of Pseudomonas aeruginosa infection in patients with cystic fibrosis; Lang AB et al.; Patients with cystic fibrosis (CF; N = 26) and with no prior history of infection with Pseudomonas aeruginosa were immunized with an octavalent O-polysaccharide-toxin A conjugate vaccine . During the next 4 years, 16 patients (61.5%) remained free of infection and 10 (38.5%) became infected . Total serum antilipopolysaccharide (LPS) antibody levels induced by immunization were comparable in infected and noninfected patients . In contrast, 12 of 16 noninfected versus 3 of 10 infected patients (p = 0.024) mounted and maintained a high-affinity anti-LPS antibody response . When compared retrospectively with the rate in a group of age- and gender-matched, nonimmunized, noncolonized patients with CF, the rate at which P . aeruginosa infections were acquired was significantly lower (p < or = 0.02) among all immunized versus nonimmunized patients during the first 2 years of observation . Subsequently, only those immunized patients who maintained a high-affinity anti-LPS antibody response had a significant reduction (p < or = 0.014) in the rate of infection during years 3 and 4 . Smooth, typeable strains of P . aeruginosa predominated among immunized patients; rough, nontypeable strains were most frequently isolated from nonimmunized patients . Mucoid variants were isolated from one immunized patient versus six nonimmunized patients . These results indicate that the induction of a high-affinity P . aeruginosa anti-LPS antibody response can influence the rate of infection in patients with CF.

Eur J Biochem, 1995 Oct 15, 233(2), 554 - 60
Structure of metal site in Cd-substituted His117Gly mutant of azurin with and without addition of imidazole derivatives; Danielsen E et al.; The present work uses 111mCd-perturbed angular correlations of gamma-rays (PAC) to investigate the structure of the metal site of the His117Gly mutant of Pseudomonas aeruginosa azurin in aqueous solution and the effect on the structure upon addition of the following exogenous ligands: imidazole, 4-methyl imidazole, 1-methyl imidazole, 2-methyl imidazole and histidine . The nuclear quadrupole interaction of cadmium bound to the mutant without addition of exogenous ligands shows a strong pH dependence with three different nuclear quadrupole interactions consistent with two pKa values at about 7.2 and 8.6 at 2 degrees C . Addition of the imidazole derivatives resulted in a significant change in the PAC spectrum showing that they coordinate . This is in accordance with observations by EPR for the same mutant with copper at the metal site {den Blaauwen, T . & Canters, G . W . (1993) J . Am . Chem . Soc . 115, 1121-1129} . However, whereas EPR and ultraviolet/visual absorption show that the characteristics of the wild-type copper protein are regained by addition of the imidazole derivatives with the exception of the possible bidentates (histidine and histamine), the comparison of the PAC results to model calculations shows that the cadmium ion must be fourfold coordinated in most cases, probably binding an additional water or hydroxide ligand . A fourfold coordination is in contrast to cadmium-substituted wild-type azurin where PAC data inferred a threefold coordination by a Cys and two His residues {Danielsen, E . Bauer, R., Hemmingsen, L., Andersen . M., Bjerrum, M . J., Butz, T., Troger, W., Canters, G . W., Hoitink, C . W . G., Karlsson, G., Hansson, O . & Messerschmidt, A . (1995) J . Biol . Chem . 270, 573-580}

J Immunol, 1995 Oct 15, 155(8), 3912 - 21
Diverse VH and V kappa genes encode antibodies to Pseudomonas aeruginosa LPS; Emara MG et al.; The molecular nature of the murine Ab response to Pseudomonas aeruginosa LPS was examined using a panel of 10 well-defined anti-LPS mAbs . Abs to P . aeruginosa LPS are encoded by diverse V-genes, with at least five VH and four V kappa gene families represented in these Abs . The Abs that bind to hydrophilic O-polysaccharide side chains of B-band LPS and A-band LPS are encoded by VH J558, SM7, and J606 gene families, while Abs to hydrophobic core and lipid A regions are encoded by X24, SM7, and Q52 gene families . All active JH and only two J kappa (J kappa 2 and J kappa 5) germ-line genes are utilized in the anti-LPS Abs examined . Four of six anti-P . aeruginosa mAbs used diversity genes of the DSP2 gene family . Interestingly, JH1 and JH2 use was observed in three mAbs that reacted with hydrophilic LPS epitopes (O-polysaccharide, A-band LPS), whereas JH3 and JH4 use was observed in three mAbs that bound to the more hydrophobic regions of LPS (core, lipid A) . Point mutations were observed in framework and complementarity-determining regions (CDRs) of VH and VL genes, suggesting an Ag-driven maturation process in response to P . aeruginosa LPS . Mutations occurred in all heavy chain CDRs, as well as in CDR1 and CDR3 of the light chain, indicating an important role of these regions in binding to LPS . These data suggest that diverse VH and V kappa genes encode Abs to LPS from P . aeruginosa.

Biochemistry, 1995 Oct 10, 34(40), 12963 - 72
Structure-function analysis of the adherence-binding domain on the pilin of Pseudomonas aeruginosa strains PAK and KB7; Wong WY et al.; The pili of Pseudomonas aeruginosa mediate bacterial binding to human epithelial cell surfaces . We have previously shown that a 17-residue synthetic peptide, KCTSDQDEQFIPKGCSK, corresponding to the C-terminal sequence of the PAK pilin protein (residues 128-144) contains the adherence binding domain . Another pilin strain, KB7, has been cloned and sequenced {Paranchych et al . (1990) in Pseudomonas Biotransformations, Pathogenesis and Evolving Biotechnology, pp 343-351, American Society for Microbiology, Washington, DC} . The C-terminal 17-residue sequence of the KB7 pilin is SCATTVDAKFRPNGCTD, which is semiconserved as compared to the PAK sequence . In this study, the interactions between the A549 human lung carcinoma cells and the two P . aeruginosa pilin strains were elucidated using a single alanine replacement analysis on the C-terminal 17-residue synthetic peptide of the pilins . The ability of these peptide analogs to inhibit the binding of the biotinylated PAK pili to A549 cells was assessed . Six PAK amino acid side chains (Ser131, Gln136, Ile138, Pro139, Gly141, and Lys144) and nine KB7 side chains (Ala130, Thr131, Thr132, Val133, Asp134, Ala135, Lys136, Arg138, and Pro139) were found to be important in mediating the pilus adhesin binding to A549 cells . In addition, a flexible peptide analog with both cysteine residues replaced by alanine failed to inhibit the binding of PAK pili to A549 cells . This suggests that the interactions between the pilin ligand and the A549 cell surface receptors are dependent on the conformation mediated by the disulfide bridge (Cys129 and Cys142) . The residues considered to contribute to bacterial adherence are referred to as the "adhesintope" . Four PAK and three KB7 side chains were located in a structurally more rigid region of the disulfide-bridged peptide as revealed by two-dimensional NMR studies {McInnes et al . (1993) Biochemistry 32, 13432-13440} . The structural aspects of the pilin-receptor interactions related to the mapped adhesintope sequences are discussed . The dissimilarities between the PAK and KB7 adhesintopes may suggest that compensatory mutations could occur among different pilin strains so as to allow the pilin adhesins to interact with the same receptor.

Microb Drug Resist, 1995 Fall, 1(3), 219 - 22
Risk factor assessment for the acquisition of fluoroquinolone-resistant isolates of Pseudomonas aeruginosa in a community-based hospital; Baddour LM et al.; A case-control study was performed in a community-based nonteaching hospital to assess patient risk factors for the acquisition of fluoroquinolone-resistant isolates of Pseudomonas aeruginosa . Fifty-five patients who were hospitalized between July 1, 1993 and December 31, 1993 and who had P . aeruginosa recovered from a clinical specimen were included in the analysis . Two patient populations were designated based on the fluoroquinolone susceptibility of their P . aeruginosa isolates . Statistical evaluation using univariate analysis of demographic and clinical data from the 42 patients with quinolone-susceptible P . aeruginosa and the 13 patients with quinolone-resistant P . aeruginosa demonstrated that prior receipt of a fluoroquinolone was the only significant risk factor for the subsequent emergence of fluoroquinolone resistance among P . aeruginosa isolated from patients hospitalized in this small community-based institution (p = 0.0196) . Multivariate analysis supported the finding that prior receipt of a fluoroquinolone was the major risk factor for the isolation of fluoroquinolone-resistant P . aeruginosa (p = 0.0004); isolation of this Gram-negative bacillus from sputum (p = 0.0306) and a history of recent surgery (p = 0.0058) were also significantly associated as risk factors for resistance.

Proc Natl Sci Counc Repub China B, 1995 Oct, 19(4), 216 - 24
Production of lytic enzyme from Pseudomonas aeruginosa M-1001; Wang SL et al.; Pseudomonas aeruginosa M-1001 produced both hen-egg-white lysozyme inhibitors and lytic enzyme in the culture broth . The lytic enzyme produced was not inhibited by the lysozyme inhibitors . Maximal lytic activity was obtained when the strain was grown aerobically in a medium consisting of 0.25% glucose, 0.75% soluble strach, 0.25% beef extract, 0.25% Polypepton, 0.25% sodium L-glutamate and 0.0001% NaCl (pH 6), at 37 degrees C after 36 hrs . The lytic enzyme was stable at pH from 6 to 8 and temperatures below 40 degrees C . Many bacteria and Saccharomyces cerevisiae were found to be inhibited by the crude lytic enzyme produced from the M-1001 strain except for the strain itself and a few other microorganisms.

Antibiot Khimioter, 1995 Oct, 40(10), 30 - 5
{Effect of drugs of various groups on the course of experimental local pyo-inflammatory processes}; Men'shikov DD et al.; To develop new approaches to providing higher efficacy of antibacterial therapy of purulent infection, experiments on 104 rats were performed . A decrease in the inflammation was shown in a series of the experiments with the dermonecrotic test using mono- and mixed cultures of Staphylococcus aureuo, Pseudomonas aeruginosa and Escherichia coli at the background of the animal treatment with anapriline and heparin . The effect of mezatone and dicinone was the opposite one . The drugs had different effects on the host response to the introduction of microorganisms of various species as mono- and mixed cultures . The experiments on a group of animals with wound infection not subjected to the preliminary alteration of the tissues demonstrated that the treatment with gentamicin and anapriline combinations was more efficient than the gentamicin monotherapy . The use of anapriline improved the antibiotic pharmacokinetics, had a favourable effect on the wound reparation, promoted a decrease in the count of viable microbes in the wound secretion and increased the antibiotic concentration gradient.

Antimicrob Agents Chemother, 1995 Oct, 39(10), 2331 - 6
In vitro antibacterial activity and beta-lactamase stability of a new carbapenem, BO-2727; Inoue K et al.; The in vitro activity of BO-2727, a new carbapenem, was compared with those of meropenem, biapenem, imipenem, and ceftazidime . BO-2727 was four- or eightfold more active than the other carbapenems against methicillin-resistant staphylococci and Pseudomonas aeruginosa strains, including imipenem- and ceftazidime-resistant bacteria . BO-2727 was quite stable to penicillinases, cephalosporinases, and oxyiminocephalosporinases, but not to metallo-beta-lactamase . Time-kill studies against Staphylococcus aureus Smith, Escherichia coli ML4707, and P . aeruginosa GN11189 showed that BO-2727 has potent bactericidal activity at concentrations greater than the MIC.

Antimicrob Agents Chemother, 1995 Oct, 39(10), 2248 - 52
Role of mutations in DNA gyrase genes in ciprofloxacin resistance of Pseudomonas aeruginosa susceptible or resistant to imipenem; Cambau E et al.; In Pseudomonas aeruginosa, resistance to imipenem is mainly related to a lack of protein OprD and resistance to fluoroquinolones is mainly related to alterations in DNA gyrase . However, strains cross resistant to fluoroquinolones and imipenem have been selected in vitro and in vivo with fluoroquinolones . We investigated the mechanisms of resistance to fluoroquinolones in 30 clinical strains of P . aeruginosa resistant to ciprofloxacin (mean MIC, >8 micrograms/ml), 20 of which were also resistant to imipenem (mean MIC, >16 micrograms/ml) . By immunoblotting, OprD levels were markedly decreased in all of the imipenem-resistant strains . Plasmids carrying the wild-type gyrA gene (pPAW207) or gyrB gene (pPBW801) of Escherichia coli were introduced into each strain by transformation . MICs of imipenem did not change after transformation, whereas those of ciprofloxacin and sparfloxacin dramatically decreased (25- to 70-fold) for all of the strains . For 28 of them (8 susceptible and 20 resistant to imipenem), complementation was obtained with pPAW207 but not with pPBW801 . After complementation, the geometric mean MICs of ciprofloxacin and sparfloxacin (MICs of 0.3 microgram/ml and 0.5 microgram/ml, respectively) were as low as those for wild-type strains . Complementation was obtained only with pPBW801 for one strain and with pPAW207 and pPBW801 for one strain highly resistant to fluoroquinolones . These results demonstrate that in clinical practice, gyrA mutations are the major mechanism of resistance to fluoroquinolones even in the strains of P . aeruginosa resistant to imipenem and lacking OprD, concomitant resistance to these drugs being the result of the addition of at least two independent mechanisms.

J Ind Microbiol, 1995 Oct, 15(4), 305 - 10
Quantification of the ease of removal of bacteria from surfaces; Eginton PJ et al.; This paper describes a technique which reproducibly quantifies the ease of removal of microorganisms from surfaces . Tiles (22 mm x 22 mm) of various materials were colonised with Staphylococcus epidermidis NCTC 11047, Escherichia coli K12 HB101 or Pseudomonas aeruginosa PaWH, by submersion, for various times (2 min-48 h), in inoculated Tryptone Soya broth (37 degrees C) . Colonised tiles were blotted onto a Tryptone Soya agar plate for 1 min and the process was repeated through a succession of agar plates . The final plate contained tetrazolium salts (0.05% w/v) and was incubated in situ with the tile . Tetrazolium plates indicated that very few organisms remained on the tiles after 15 successive blots . In all instances, the number of recovered colonies per plate decreased exponentially with plate succession number, according to the relationship, CFU = A.10-kN, where CFU is the number of colonies transferred, k is the removal exponent, A is the intercept and N is the plate succession number . Removal exponents differed significantly between organisms (P > 0.95), depended on the nature of the test surface, and decreased as the inital attachment and colonisation time was increased from 2 min-48 h . Intercept values (A) but not the gradients were dependent upon the initial numbers of bacteria in suspension . These data indicate that the gradients derived from counting recoverable viable cells from successive blots of test tiles onto agar is a measure of the strength of attachment of the organisms to the surface.

Immunol Cell Biol, 1995 Oct, 73(5), 440 - 5
Histopathology of the lung following intratracheal challenge with live Pseudomonas aeruginosa in intestinally immunized rats; Wilson NR et al.; This paper examines the histology of rat lungs following intestinal immunization with killed mucoid Pseudomonas aeruginosa and subsequent pulmonary challenge with live P . aeruginosa . The lungs of non-immune challenged rats developed a confluent haemorrhagic pneumonitis with degeneration and sloughing of the mucosa of the airways; perivascular infiltration with mononuclear cells was apparent 1-2 h post-challenge; some neutrophils were present by 2 h post-challenge; by 12 h post-challenge oedema and intra-alveolar haemorrhage were prominent and Gram-negative organisms were seen in large quantities . In contrast, immunized challenged animals showed a pronounced neutrophilic response 1-2 h post challenge; by 12 h post-challenge patchy abscesses were apparent with resolving inflammation and no organisms visible . The findings suggest that intestinal immunization prevents the development of fatal P . aeruginosa infections in the lung by accelerating the recruitment of polymorphonuclear neutrophils.

Immunol Cell Biol, 1995 Oct, 73(5), 418 - 24
Pulmonary immunity to Pseudomonas aeruginosa; Cripps AW et al.; Pseudomonas aeruginosa, an opportunistic bacterial pathogen, is a major course of morbidity and mortality in subjects with compromised respiratory function despite the significant advances in therapeutic practices . The bacteria produces an armoury of products which modify its infective niche to ensure bacterial survival . The role of antibody in protection against pulmonary infection remains poorly defined . Protection appears to be associated with opsonizing antibody whilst some other antibody responses may be deleterious and promote further lung damage . Cell mediated responses are clearly important in protection against infection . This review proposes a vaccine strategy aimed at enhancing specific T cell responses in the lung which, though T cell-derived cytokines, drive the recruitment of neutrophils to the lung and the subsequent activation of these cells results in the clearance of bacteria from the lung.

J Antimicrob Chemother, 1995 Oct, 36(4), 707 - 11
In-vitro activities of various antibiotics, alone and in combination with amikacin against Pseudomonas aeruginosa; Gerceker AA et al.; The in-vitro activities of various antibiotics, either alone or in combination with amikacin were assessed in clinical isolates of Pseudomonas aeruginosa . Clinically relevant synergic interactions were most frequent with piperacillin (92%), ceftazidime (87%) and aztreonam (84%), and less frequent with imipenem (35%) . Ciprofloxacin-amikacin showed only an additive effect.

J Antimicrob Chemother, 1995 Oct, 36(4), 631 - 9
Incorporation, release and in-vitro antibacterial activity of liposomal aminoglycosides against Pseudomonas aeruginosa; Omri A et al.; Amikacin, netilmicin and tobramycin were incorporated into either anionic or cationic liposomes prepared by sonication . The influence of lipid constituents (charges) on encapsulation efficiency was determined after lysis of vesicles by 0.2% (v/v) Triton X-100 . The in-vitro activities of the liposomal aminoglycosides were evaluated against Pseudomonas aeruginosa by agar dilution and compared with free antibiotics . Normal human pooled sera, incubated at 37 degrees C, were supplemented with anionic or cationic liposomes containing known fixed concentrations of amikacin, netilmicin or tobramycin . At various time intervals (0-48 h), samples were taken and antibiotic concentrations determined by the enzyme multiplied immunoassay technique (EMIT) . The encapsulation efficiency of cationic liposomes (amikacin 17.1 +/- 1.55%, netilmicin: 5.63 +/- 1.13%, tobramycin 6.7 +/- 0.5%) was approximately 30% higher than that of anionic liposomes (amikacin 12.3 +/- 0.95%, netilmicin 4.0 +/- 0.06%, tobramycin 5.13 +/- 0.18%) . Anionic and cationic liposomes in human serum still retained 79.13 +/- 4.04% and 82.71 +/- 2.6% of amikacin, 50.67 +/- 1.8% and 38.6 +/- 0.8% of netilmicin, and 89.09 +/- 1.0% and 88.93 +/- 0.4% of tobramycin, respectively, after 48 h of incubation at 37 degrees C under 5% CO2 . The MICs of amikacin (2, 16 and 2 mg/L), netilmicin (2, 1 and 4 mg/L) and tobramycin (1, 2 and 4 mg/L) in free, anionic or cationic liposomal formulations, respectively, were relatively comparable except for anionic liposomal amikacin for which the MIC was increased eight-fold . Empty cationic or anionic liposomes had no effect on bacterial growth . Cationic liposomes containing aminoglycosides should be evaluated further for the treatment of pseudomonal infection.

Can J Microbiol, 1995 Oct, 41(10), 910 - 7
DNA hybridization analysis of the Pseudomonas aeruginosa elastase gene (lasB) from different clinical isolates; Hamood AN et al.; Pseudomonas aeruginosa produces several extracellular virulence factors including elastase (which is encoded by lasB) . Recently, we examined several clinical isolates of P . aeruginosa for the production of toxin A, elastase, exoenzyme S, and phospholipase C . Although the majority of the isolates produced a high level of elastase, a few isolates produced either very low or no detectable elastase . In this study, we tried to determine the presence of restriction site heterogeneity within lasB from these isolates and the possible correlation between such heterogeneity and the observed variation in elastase production . Chromosomal DNA from the isolates was digested with different restriction enzymes and examined by Southern blot hybridization experiments using two lasB probes . One lasB probe covers 636 bp of lasB structural gene while the other covers 240 bp of the lasB upstream region . Chromosomal DNA from P . aeruginosa PAO1 and PA103 was used as controls . Results indicate that chromosomal DNA from all isolates hybridized to both lasB probes . Depending on the restriction enzyme used for DNA digestion, lasB from 3 to 12% of the isolates showed different patterns of hybridization with the lasB structural gene probe . However, no difference in the hybridization pattern was seen with the lasB upstream probe . With the exception of one isolate, hybridization of genomic DNA from different isolates (with both probes) produced a single hybridization band . In that isolate, an additional hybridization band was detected . Immunoblotting experiments confirmed that elastase protein is not produced by 6 out of 67 isolates . However, lasB from four of these elastase-deficient strains showed no difference in the hybridization pattern with either lasB probe.(ABSTRACT TRUNCATED AT 250 WORDS)

Vaccine, 1995 Oct, 13(14), 1288 - 93
Effect of conjugation methodology, carrier protein, and adjuvants on the immune response to Staphylococcus aureus capsular polysaccharides; Fattom A et al.; Conjugate vaccines were prepared with S . aureus type 8 capsular polysaccharide (CP) using three carrier proteins: Pseudomonas aeruginosa exotoxin A (ETA), a non-toxic recombinant ETA (rEPA), and diphtheria toxoid (DTd) . Adipic acid dihydrazide (ADH) or N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) was used as a spacer to link the CP to carrier protein . All conjugates gave a high immune response with a boost after the second immunization . Conjugates prepared with ADH gave higher antibody titers than conjugates prepared with SPDP . IgG1 was the primary subclass elicited by all conjugates regardless of the carrier protein or the conjugation method used to prepare the vaccines . The non-immunogenic CP and the conjugates were formulated with either monophosphoryl lipid A (MPL), QS21, or in Novasomes and evaluated in mice . While the adjuvants failed to improve the immunogenicity of the nonconjugated CP, a more than fivefold increase in the antibody levels was observed when these adjuvants were used with the conjugates . Significant rises in IgG2b and IgG3 were observed with all formulations . The enhancement of the immunogenicity and the IgG subclass shift, as seen with some adjuvants, may prove to be important in immunocompromised patients.

Antonie Van Leeuwenhoek, 1995 Oct, 68(3), 225 - 9
Chromosome-encoded inducible copper resistance in Pseudomonas strains; Vargas E et al.; Nine Pseudomonas strains were selected by their high copper tolerance from a population of bacteria isolated from heavy-metal polluted zones . Copper resistance (Cu(r)) was inducible by previous exposure of cultures to subinhibitory amounts of copper sulfate . All nine strains possessed large plasmids, but transformation and curing results suggest that Cu(r) is conferred by chromosomal genes . Plasmid-less Pseudomonas aeruginosa PAO-derived strains showed the same level of Cu(r) as environmental isolates and their resistance to copper was also inducible . Total DNA from the environmental Pseudomonas, as well as from P . aeruginosa PAO strains, showed homology to a Cu(r) P . syringae cop probe at low-stringency conditions but failed to hybridize at high-stringency conditions.

Shock, 1995 Oct, 4(4), 274 - 81
S-ethylisothiourea, a nonamino acid inhibitor of nitric oxide synthase, reverses septic vasodilation in sheep; Booke M et al.; S-ethylisothiourea (3936W92) is a nonamino acid antagonist of nitric oxide synthase . Its selectivity for the inducible form of nitric oxide synthase is twice as high as for the constitutive form of the enzyme . We tested 3936W92 in 20 sheep, which were surgically prepared for chronic study . In all sheep, a hyperdynamic sepsis was induced by a continuous infusion of live Pseudomonas aeruginosa . After 24 h of sepsis, nine sheep received a continuous infusion of 3936W92 over the next 24 h, whereas the control group (n = 9) received saline instead . Two sheep died within the first 24 h of sepsis . 3936W92 caused a complete reversal of the hyperdynamic circulation, while sheep in the control group remained hyperdynamic . Although the cardiac index decreased significantly during treatment with 3936W92 (7.9 +/- .8 vs . 6.0 +/- .7 l/min/m2), a simultaneous increase in oxygen extraction prevented oxygen consumption from falling.

Trends Microbiol, 1995 Oct, 3(10), 392 - 6
Heat-shock proteins in host-pathogen interactions: implications for cystic fibrosis; Polla BS et al.; The expression of heat-shock proteins by both pathogen and host cells during the phagocytosis of Staphylococcus aureus and Pseudomonas aeruginosa, two bacterial species that colonize the airways of patients with cystic fibrosis, probably contributes to pulmonary inflammation in cystic fibrosis . Here, we discuss the likely signals for heat-shock-protein induction within host and bacterial cells.

Biol Trace Elem Res, 1995 Oct, 50(1), 25 - 31
Effects of metals on elastase from Pseudomonas aeruginosa SES-938-1; Kocabiyik S et al.; Among the numerous virulance factors produced by Pseudomonas aeruginosa, elastase is the one most often associated with pathogenesis . In this study, effects of various metal ions on elastase from a new isolate of P . aeruginosa (Strain SES-938-1) was investigated . Crude elastase was prepared from culture supernatant via salting out by ammonium sulfate, and then desalting and concentrating the sample using a centricon microconcentrator . Activities were measured at 450 nm using N-succinyl-L-(ala)3-p-nitroanilide as the substrate . The metal chelating agents EDTA and EGTA inhibited the Pseudomonas elastase, which shows that the enzyme is a typical metalloproteinase . At a 10-mM concentration, Mn2+, Ni2+, and Zn2+ strongly inhibited the elastase, whereas Mg2+ effect was negligable . There was a gradual decrease in the enzyme activity in accordance with an increase in the concentration of metal ions.

Jpn J Antibiot, 1995 Oct, 48(10), 1590 - 6
{In vitro antibacterial activities of carbapenems and other antibiotics against Pseudomonas aeruginosa determined using low-amino-acid agar}; Kouda M et al.; MICs of imipenem (IPM), panipenem (PAPM), cefozopran (CZOP), cefpirome (CPR), gentamicin (GM), tobramycin (TOB) and amikacin (AMK) against Pseudomonas aeruginosa were determined using Mueller-Hinton agar and low-amino-acid agar . On Mueller-Hinton agar, the antibacterial activity of TOB was superlative, followed in order by GM, CZOP, IPM, AMK, PAPM and CPR, whereas on low-amino-acid agar, the order changed to IPM, PAPM, TOB, CZOP, GM, AMK and CPR . The largest decrease of MICs was seen with PAPM on low-amino-acid agar, and the antibacterial activity of PAPM was not stronger than that of IPM . The growth of P . aeruginosa on the low-amino-acid agar were significantly weaker than that on Mueller-Hinton agar, hence the evaluation of appearance colonies was difficult and misjudgement may result . Based on the above observations, we believe further investigations are needed before the application of low-amino-acid agar becomes routine.

Genetika, 1995 Oct, 31(10), 1375 - 9
{Mucoid clones of Pseudomonas aeruginosa PAO1, surviving after induction of prophage transposons}; Krylov VN et al.; The origin and properties of mucoid clones were studied . The clones were selected with high frequency after thermo-induction of Pseudomonas aeruginosa lysogenic for phage transposons (PT) . The production of alginate does not promote the survival of lysogenic bacteria at 42 degrees C . Mucoid clones were shown to appear before thermo-induction; the frequency of their formation does not depend on the specificity of the mutator effect intrinsic to different PT . Phenotypic differences typical of mucoid clones can be mediated by different mutations promoting clone survival at 42 degrees C and by simultaneously arising additional mutations . The SL21 mucoid clone selected among clones of P . aeruginosa PAO1 resistant to PT of B3 possesses an additional trait of phage resistance at 42 degrees C . The presence of D3112 cts 15 prophage has no significant effect on the frequency of SL21 reversion to nonmucoidness . This means that the mutator effect of PT has made a slight contribution to this process . The appearance of mutations promoting the survival of the thermoinducible lysogen SL21 (D3112 cts 15) does not affect the frequency of the loss of mucoidness . Nonmucoid derivatives of SL21 were shown to differ in phage resistance at 42 degrees C and in the extent of the residual mucoidness manifested under specific conditions . Consequently, nonmucoid clones appear as a result of pseudo-reversions . Because some of these pseudo-revertants cannot again be converted to the mucoid form, it is concluded that they carry mutations in genes whose functions are obligatory for the production of alginate.

Rev Clin Esp, 1995 Oct, 195(10), 688 - 92
{Multiple organ failure in Plasmodium falciparum malaria}; Botella de Maglia J et al.; A 44-year-old Spanish woman travelled in Kenya without doing correct malarial prophylaxis . Upon her return to Spain, she suffered from Plasmodium falciparum malaria . She was initially treated with chloroquine for three days, but her state worsened and she was admitted to our intensive care unit . On admission, parasitaemia was 22% . She had hyperpyrexia, obtundation, hypotension, tachycardia, tachypnoea, jaundice, digestive haemorrhage, petechiae in her soles, oliguria with elevation of serum uraemia and creatinine, anaemia, thrombocytopaenia, hypoproteinaemia, hyponatraemia, hypocalcaemia, metabolic acidosis and parameters of disseminated intravascular coagulation . She was given quinine, sulfadoxine-pyrimethamine and clindamycin . An exchange transfusion was performed, during which an acute pulmonary oedema appeared, initially with high pulmonary artery wedge pressure . She required mechanical ventilation for 16 days and haemodialysis for 11 days . She remained in coma and had seizures which required diazepam, phenitoin and thiopentone . She received a total amount of 22 units of packed erythrocytes, 55 of platelets and 15 of plasma . After the first week, she had nosocomial infection due to Escherichia coli, Staphylococcus and Pseudomonas aeruginosa and was treated with the corresponding antibiotics . She cured completely . This case report gives us the possibility of discussing on frequent problems in the prevention and treatment of malaria, and on the treatment of severe, life-threatening malaria in the setting of the intensive care unit.

J Bacteriol, 1995 Oct, 177(20), 5872 - 7
Purification and characterization of the Pseudomonas aeruginosa NfxB protein, the negative regulator of the nfxB gene; Shiba T et al.; The protein NfxB, involved in conferring resistance to quinolones in Pseudomonas aeruginosa, has a helix-turn-helix motif which is similar to that of other DNA-binding proteins . It appears to affect the membrane-associated energy-driven efflux of some antibiotics (H . Nikaido, Science 264:382-388, 1994) . We constructed a plasmid that overproduced NfxB in Escherichia coli and purified the protein . Two species of NfxB (23 and 21 kDa), which are probably translated from different initiation codons, were isolated . Both proteins are also expressed in vivo in P . aeruginosa, with the 23-kDa NfxB being the major species . NfxB specifically binds upstream of the nfxB coding region as demonstrated by gel retardation and DNase I footprinting . Expression of the phi (nfxB'-lacZ+) (Hyb) gene was repressed in the presence of the nfxB gene product provided by a second compatible plasmid in E . coli . In the P . aeruginosa wild-type strain (PAO2142), NfxB was undetectable by immunoblotting; however, it was detected in the nfxB missense mutant (PK1013E) . These results suggested that NfxB negatively autoregulates the expression of nfxB itself . Since the 54-kDa outer membrane protein (OprJ) (N . Masuda, E . Sakagawa, and S . Ohya, Antimicrob . Agents Chemother . 39:645-649, 1995) was overproduced in nfxB mutants, NfxB may also regulate the expression of membrane proteins that are involved in the drug efflux machinery of P . aeruginosa.

FEMS Microbiol Lett, 1995 Oct 1, 132(1-2), 9 - 15
High-molecular-mass, iron-repressed cytoplasmic proteins in fluorescent Pseudomonas: potential peptide-synthetases for pyoverdine biosynthesis; Georges C et al.; High molecular-mass cytoplasmic proteins were detected in iron-starved, pyoverdine-producing Pseudomonas aeruginosa, P . chlororaphis, P . fluorescens, P . putida, P . aptata and P . tolaasii . They appeared to be specifically located in the cytoplasm and thus were termed 'IRCPs', for iron-repressed cytoplasmic proteins . A strain-dependent gel electrophoresis pattern with multiple bands of M(r) values ranging from 180 to 600 kDa was usually observed for these proteins . Strains synthesizing pyoverdines differing in their peptide part presented different IRCP gel electrophoresis profiles, whereas strains synthesizing identical pyoverdines had identical IRCP gel electrophoresis profiles . Some mutants affected in pyoverdine biosynthesis presented a perturbed IRCP pattern, and no IRCPs were detected in non-fluorescent Pseudomonas strains either unable to synthesize siderophores or synthesizing non-peptidic siderophores . The data strongly suggest that the IRCPs could be related to peptide synthetases involved in the biosynthesis of the peptidic part of pyoverdine-type siderophores.

J Med Microbiol, 1995 Oct, 43(4), 300 - 9
Mechanisms of resistance to beta-lactam antibiotics amongst Pseudomonas aeruginosa isolates collected in the UK in 1993; Chen HY et al.; Antimicrobial resistance among 1991 Pseudomonas aeruginosa isolates collected at 24 UK hospitals during late 1993 was surveyed . Three-hundred and seventy-two of the isolates were resistant, or had reduced susceptibility, to some or all of azlocillin, carbenicillin, ceftazidime, imipenem and meropenem, and the mechanisms underlying their behaviour were examined . Only 13 isolates produced secondary beta-lactamases: six possessed PSE-1 or PSE-4 enzymes and seven had novel OXA enzyme types . Those with PSE types were highly resistant to azlocillin and carbenicillin whereas those with OXA enzymes were less resistant to these penicillins . Chromosomal beta-lactamase derepression was demonstrated in 54 isolates, most of which were resistant to ceftazidime and azlocillin although susceptible to carbenicillin and carbapenems . beta-Lactamase-independent "intrinsic" resistance occurred in 277 isolates and is believed to reflect some combination of impermeability and efflux . Two forms were seen: the classical type, present in 195 isolates, gave carbenicillin resistance (MIC > 128 mg/L) and reduced susceptibility to ciprofloxacin and to all beta-lactam agents except imipenem; a novel variant, seen in 82 isolates, affected only azlocillin, ceftazidime and, to a small extent, meropenem . Resistance to imipenem was largely dissociated from that to other beta-lactam agents, and probably reflected loss of D2 porin, whereas resistance to meropenem was mostly associated with intrinsic resistance to penicillins and cephalosporins . Comparison of the present results with those of a similar study in 1982 revealed significant increases in the proportions of isolates with intrinsic resistance or stable derepression (p < 0.01, chi 2 test).(ABSTRACT TRUNCATED AT 250 WORDS)

J Med Microbiol, 1995 Oct, 43(4), 270 - 6
IgG subclass responses to Pseudomonas aeruginosa a- and b-type flagellins in patients with cystic fibrosis: a prospective study; Lagace J et al.; Sera from 20 cystic fibrosis patients, whose lungs were colonised by Pseudomonas aeruginosa, were examined in a 3-5-year prospective study for any relationship between IgG subclass antibody levels to P . aeruginosa a- and b-type flagellins and pulmonary function (FEV1 and radiological score) . Patients were divided into two groups according to their pulmonary status: group 1 comprised 11 patients with poor pulmonary status; group 2 comprised nine patients with relatively good pulmonary status . High concentrations of IgG1, IgG2 and IgG3 antibodies to flagellins, particularly to the b-type, were found in most patients . IgG4 reactivity was observed in only a few patients . Comparison of the two groups of patients showed that those with poor pulmonary status (group 1) had a significantly higher concentration (p < 0.05) of IgG3 for two of the three periods studied and of IgG2 for the last period studied . Moreover, IgG3 and IgG1 reactivities to b-type flagellin and IgG3 to a-type flagellin were also increased significantly (p < 0.05) in group 1 patients between the first and the last period studied . These patients also showed a significant (p < 0.05) time-dependent increase in IgG3 and IgG1 antibody concentrations . These data demonstrate that cystic fibrosis patients with poorer pulmonary status have higher IgG3 levels to flagellin than other cystic fibrosis patients . High concentrations of strong opsonic IgG3 and, to a lesser degree, of IgG1 antibodies may increase pulmonary inflammation and induce heightened pulmonary deterioration.

J Med Microbiol, 1995 Oct, 43(4), 258 - 61
The influence of exo-enzyme S and proteases on endogenous Pseudomonas aeruginosa bacteraemia in mice; Hirakata Y et al.; The role of Pseudomonas aeruginosa exo-enzymes was evaluated in a murine model of endogenous bacteraemia in which the bacteria invaded the bloodstream after oral dosing . Although an elastase mutant PAO-E64 was as virulent as its parent strain PAO1, an exo-enzyme S-deficient mutant, DG1-ExS5 and alkaline protease mutants PAKS-16, PAKS-17, PAKS-19, were less virulent than their parent strains, DG1 and PAKS-1, respectively (p < 0.01) . Thus exo-enzyme S and alkaline protease, but not elastase, appear to contribute to the pathogenicity of P . aeruginosa in this model.

J Infect Dis, 1995 Oct, 172(4), 1001 - 6
Susceptibility to local and systemic bacterial infections in intercellular adhesion molecule 1-deficient transgenic mice; Sarman G et al.; The contribution of intercellular adhesion molecule 1 (ICAM-1) during systemic and local bacterial infections was studied in transgenic ICAM-1-deficient and control mice that were injected intraperitoneally (ip) or intradermally (id) with Escherichia coli, Pseudomonas aeruginosa, or Staphylococcus aureus . Mortality rates, blood cultures, white blood cell (WBC) counts and absolute neutrophil counts (ANCs) were obtained daily until cultures were sterile . Six and 24 h after injections, autopsies were done on randomly selected ip-inoculated mice and biopsies were done on randomly selected id-inoculated mice . Survival rates were similar . In ICAM-1-deficient mice, ip P . aeruginosa resulted in higher incidences of bacteremia at 24 h (P = .003) and 48 h (P = .002); id S . aureus resulted in larger skin lesions (P = .026) . Leukocytosis persisted in ICAM-1-deficient mice 6 h after ip injection of E . coli; however, WBC counts and ANCs in peritoneal fluid did not differ . Although the inflammatory responses were similar histologically in ICAM-1-deficient and normal mice, differences in site- and stimulus-specific susceptibilities were noted.

Infect Immun, 1995 Oct, 63(10), 4166 - 9
Avirulence of a Pseudomonas aeruginosa algC mutant in a burned-mouse model of infection; Goldberg JB et al.; The virulence of wild-type Pseudomonas aeruginosa PAO1 and that of a genetically defined algC mutant, PAO1 algC::tet, were compared in a burned-mouse model of infection . Unlike PAO1, PAO1 algC::tet was avirulent, grew less well in the eschar, and did not disseminate to the liver of challenged animals . We have previously shown that the P . aeruginosa algC gene is required for biosynthesis of alginate and lipopolysaccharide (M.J . Coyne, Jr., K.S . Russell, C.L . Coyle, and J.B . Goldberg, J . Bacteriol . 176:3500-3507, 1994) . In order to determine whether the alginate or lipopolysaccharide (LPS) defect was responsible for the avirulence of this strain, we constructed a strain with a mutation in an alginate-specific gene, algD . PAO1-algD was virulent in the burned-mouse model, thus implicating the LPS defect in PAO1 algC::tet as the relevant alteration responsible for the avirulence of this strain.

Infect Immun, 1995 Oct, 63(10), 4072 - 7
Pseudomonas aeruginosa invasion of and multiplication within corneal epithelial cells in vitro; Fleiszig SM et al.; Pseudomonas aeruginosa is usually considered an extracellular pathogen . Using assays to determine intracellular survival in the presence of gentamicin, we have previously demonstrated that P . aeruginosa is able to invade corneal cells during infectious keratitis in mice . In vitro, P . aeruginosa was found to enter the following cells: human corneal cells removed by irrigation; epithelial cells in the cornea of rats, mice, and rabbits; and primary corneal epithelial cells cultured from rat and rabbit eyes . The level of invasion was related to the level of adherent or associated bacteria . In general, invasion was more efficient with cultured epithelial cells than with cells tested in situ . Invasion did not occur when assays were performed at 4 degrees C . Cytochalasin D but not colchicine inhibited bacterial invasion, suggesting that bacterial entry was an endocytic process dependent on actin microfilaments but not microtubules . Bacteria that invaded cultured corneal epithelial cells were found to multiply within cells . The ability of P . aeruginosa to invade and multiply within corneal epithelial cells may contribute to the virulence of this organism during infectious keratitis, since intracellular bacteria can evade host immune effectors and antibiotics commonly used to treat infection.

Chest, 1995 Oct, 108(4), 955 - 61
Clinical, pathophysiologic, and microbiologic characterization of bronchiectasis in an aging cohort; Nicotra MB et al.; STUDY OBJECTIVE: Awareness of bronchiectasis on the part of clinicians has been low in recent years, although it was previously well recognized . We believe that bronchiectasis is underdiagnosed, and that current literature is skewed toward the esoteric etiologies of bronchiectasis . DESIGN: We reviewed the clinical, radiologic, microbiologic, and physiologic findings in 123 well-studied patients with proved bronchiectasis . SETTING: The University of Texas Health Center at Tyler Hospital and Clinics . MEASUREMENTS AND RESULTS: There were 38 men and 85 women with a mean (+/- SD) age of 57.2 +/- 16.7 years; 55% were lifetime nonsmokers . Diagnosis was confirmed with CTs of the chest in 56%, by bronchogram in 28%, and surgery with the remainder . Seventy percent of patients gave a history of an antecedent potentially causative event for the bronchiectasis, usually pneumonia . Symptoms of bronchiectasis included chronic cough with the production of purulent sputum, hemoptysis, recurrent fever, and pleurisy . The finding of crackles on chest examination was the rule (70%) with wheezing present in 34% of the group . Pulmonary function studies documented airway obstruction to be present in 54% of the lifetime nonsmokers . The chest radiographs were abnormal in 91.3%, showing fibrotic stranding and infiltrates . A variety of pathologic microbial flora, particularly Pseudomonas aeruginosa and other opportunistic organisms, were isolated from the sputum . Patients who had smoked had much the same picture as nonsmokers, although they had a greater degree of airway obstruction . CONCLUSIONS: A characteristic clinical picture of bronchiectasis emerges after review and evaluation of these data . Knowledge of this picture should allow ready recognition of the disease.

Am J Respir Crit Care Med, 1995 Oct, 152(4 Pt 1), 1353 - 7
Screening Young syndrome patients for CFTR mutations; Friedman KJ et al.; Young syndrome is characterized by obstructive azoospermia associated with chronic sinobronchial disease of an infectious nature, but normal sweat-gland and pancreatic function as well as normal nasal potential differences . Congenital bilateral absence of the vas deferens (CBAVD) in some patients arises from mutations within the cystic fibrosis (CF) transmembrane regulator (CFTR) gene . Because of some similarities between Young syndrome, CF, and CBAVD, we evaluated 13 patients with Young syndrome, including screening for more than 30 different mutations within the CFTR gene . The mean age of the patients was 43 yr (range, 32 to 50 yr), and all were of northern European extraction . The sweat chloride concentration was normal in all patients (mean = 29 mEq/L; range, 8 to 43 mEq/L) . Most had intermittent bronchial and sinus infections, but none was chronically colonized with Staphylococcus aureus or Pseudomonas aeruginosa . The FEV1 was normal or only mildly reduced in most patients (mean = 74%; range, 48 to 100% predicted) . Of 26 Young syndrome chromosomes, we identified one with the recognized CF mutation delta F508 . The incidence of CFTR mutations (1 in 26) did not differ significantly from the expected carrier frequency in this population . In summary, it is unlikely that the typical Young syndrome patient has a clinical disease associated with CFTR mutation on both alleles.

Am J Respir Crit Care Med, 1995 Oct, 152(4 Pt 1), 1337 - 46
Vaccination promotes TH1-like inflammation and survival in chronic Pseudomonas aeruginosa pneumonia in rats; Johansen HK et al.; In a rat model of chronic Pseudomonas aeruginosa lung infection mimicking cystic fibrosis (CF) we studied whether the inflammatory response could be altered by vaccination . Rats were immunized with either a depolymerized alginate toxin A conjugate (D-ALG toxin A), purified alginate, an O-polysaccharide toxin A conjugate, or sterile saline . After challenge none of the rats immunized with D-ALG toxin A died, in contrast to the other two vaccine groups combined (p = 0.03) . A significant reduction in the severity of the macroscopic lung inflammation was seen in rats immunized with D-ALG toxin A, compared with the other three groups (p = 0.009) . The histopathologic response in the control rats was dominated by numerous polymorphonuclear leukocytes (PMN) surrounding the alginate beads . In contrast, the histopathologic response in rats immunized with D-ALG toxin A changed within the first week after challenge from predominantly PMNs (TH2-like) to a chronic-type inflammation dominated by mononuclear leukocytes (TH1-like) . In accordance, the antibody titers induced by the D-ALG toxin A vaccine were not different from those of the control rats after challenge . This study identifies a possible new way of modifying the inflammation and thereby preventing the PMN-mediated lung tissue damage during chronic P . aeruginosa lung infection in CF.

Genitourin Med, 1995 Oct, 71(5), 280 - 5
Open lung biopsy for investigation of acute respiratory episodes in patients with HIV infection and AIDS; Miller RF et al.; BACKGROUND--Open lung biopsy (OLB) is rarely necessary for investigation of HIV positive patients with acute respiratory episodes because of the high yield from fibreoptic bronchoscopy with bronchoalveolar lavage (BAL) . METHODS--A retrospective review of OLB in HIV positive patients admitted to a specialist inpatient unit with acute respiratory symptoms was carried out in order to define clinical indications, diagnostic yield, impact on management, complications and outcome . RESULTS--OLB was performed in 23 patients; 21 had undergone one or more bronchoscopies with BAL (5 also had negative results from transbronchial biopsy) . Indications for OLB were: Group A, 15 patients thought clinically to have pneumocystis pneumonia but not responding to treatment; Group B, 4 patients with focal chest radiographic abnormalities; Group C, 4 patients with diffuse radiographic abnormalities and miscellaneous conditions . Preoperative PaO2 (on air) ranged from 4.4 to 14.5 (mean = 9.5) kPa . The results of OLB were in Group A 5 patients had non specific interstitial pneumonitis (NIP), 1 also had Kaposi's sarcoma, 4 had pneumocystis pneumonia (1 also had bronchiolitis obliterans organising pneumonia {BOOP}), 3 had Kaposi's sarcoma and 1 had BOOP and emphysema, 1 had pulmonary infarction and no infection and 1 had normal lung tissue . In Group B diagnoses were NIP, B cell lymphoma, occult alveolar haemorrhage and Pseudomonas aeruginosa pneumonia with BOOP; In Group C 2 patients had NIP and 2 had pneumocystis pneumonia (1 also had cytomegalovirus pneumonitis) . All patients survived surgery and none required mechanical ventilation . OLB results significantly affected management; in Group A inappropriate treatment was discontinued in 11 patients found not to have pneumocystis pneumonia, and alternative therapy was begun in the 4 with pneumocystis and in Groups B and C 6 patients began specific therapy; unnecessary therapy was avoided in one and antimicrobial treatment was modified in one . CONCLUSIONS--Open lung biopsy in HIV positive patients with focal and diffuse radiographic abnormalities has a high diagnostic yield and low morbidity . This investigation should be considered in those with acute respiratory episodes and negative results from bronchoscopic investigations or who have contra-indications to this procedure.

J Biol Chem, 1995 Sep 29, 270(39), 22882 - 9
Cloning, sequencing, and regulation of the glutathione reductase gene from the cyanobacterium Anabaena PCC 7120; Jiang F et al.; Glutathione reductase (GR) was purified from the cyanobacterium Anabaena PCC 7120 . A 3-kilobase genomic DNA fragment containing the coding sequence for the GR gene (gor) was identified and cloned by polymerase chain reaction based on sequences of selected peptides isolated from proteolyzed GR . The coding sequence encompassing 458 amino acid residues, as well as 360 base pairs of the 5'-flanking region and 430 base pairs of the 3'-flanking region, were determined . Genomic Southern analysis indicates that gor is a single-copy gene . A gor antisense RNA probe hybridized with a 1.4-kilobase transcript, suggesting that the gene is not part of an operon including additional genes . The deduced GR amino acid sequence shows 41 to 48% identity with those of human, Escherichia coli, Pseudomonas aeruginosa, pea, and Arabidopsis thaliana GR . The coding sequence of GR was overexpressed in a GR-deficient E . coli strain, SG5, and the recombinant protein was purified . Anabaena GR is NADPH-linked, but a Lys residue replaces an Arg residue involved in NADPH binding in GR from other species . In addition, Anabaena GR carries the GXGXXG "fingerprint" motif which otherwise characterizes NAD(H)-dependent enzymes . These differences may contribute to the lack of affinity for 2',5'-ADP-Sepharose 4B of Anabaena GR . Three E . coli-type promoter sequences and a BifA/NtcA binding motif were found upstream of the open reading frame . The middle and the proximal promoters were shown to be active . However, the use of the middle promoter was dependent on the nitrogen source in the culture medium . Both GR activity and GR protein concentration increased in ammonium grown cultures in which both the middle and proximal promoters were used for transcriptional initiation . The BifA/NtcA-binding site overlaps the middle promoter sequence and may thus be involved in regulation of differential transcription.

Proc Natl Acad Sci U S A, 1995 Sep 26, 92(20), 9427 - 31
Multiple N-acyl-L-homoserine lactone signal molecules regulate production of virulence determinants and secondary metabolites in Pseudomonas aeruginosa; Winson MK et al.; Pseudomonas aeruginosa produces a spectrum of exoproducts many of which have been implicated in the pathogenesis of human infection . Expression of some of these factors requires cell-cell communication involving the interaction of a small diffusible molecule, an "autoinducer," with a positive transcriptional activator . In P . aeruginosa PAO1, LasI directs the synthesis of the autoinducer N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL), which activates the positive transcriptional activator, LasR . Recently, we have discovered a second signaling molecule-based modulon in PAO1, termed vsm, which contains the genes vsmR and vsmI . Using HPLC, mass spectrometry, and NMR spectroscopy we now establish that in Escherichia coli, VsmI directs the synthesis of N-butanoyl-L-homoserine lactone (BHL) and N-hexanoyl-L-homoserine lactone (HHL) . These compounds are present in the spent culture supernatants of P . aeruginosa in a molar ratio of approximately 15:1 and their structures were unequivocally confirmed by chemical synthesis . Addition of either BHL or HHL to PAN067, a pleiotropic P . aeruginosa mutant unable to synthesize either of these autoinducers, restored elastase, chitinase, and cyanide production . In E . coli carrying a vsmR/vsmI'::lux transcriptional fusion, BHL and HHL activated VsmR to a similar extent . Analogues of these N-acyl-L-homoserine lactones in which the N-acyl side chain has been extended and/or oxidized at the C-3 position exhibit substantially lower activity (e.g., OdDHL) or no activity (e.g., dDHL) in this lux reporter assay . These data indicate that multiple families of quorum sensing modulons interactively regulate gene expression in P . aeruginosa.

Proc Natl Acad Sci U S A, 1995 Sep 26, 92(20), 9308 - 12
The crystal structure of Pseudomonas aeruginosa exotoxin domain III with nicotinamide and AMP: conformational differences with the intact exotoxin; Li M et al.; Domain III of Pseudomonas aeruginosa exotoxin A catalyses the transfer of ADP-ribose from NAD to a modified histidine residue of elongation factor 2 in eukaryotic cells, thus inactivating elongation factor 2 . This domain III is inactive in the intact toxin but is active in the isolated form . We report here the 2.5-A crystal structure of this isolated domain crystallized in the presence of NAD and compare it with the corresponding structure in the intact Pseudomonas aeruginosa exotoxin A . We observe a significant conformational difference in the active site region from Arg-458 to Asp-463 . Contacts with part of domain II in the intact toxin prevent the adoption of the isolated domain conformation and provide a structural explanation for the observed inactivity . Additional electron density in the active site region corresponds to separate AMP and nicotinamide and indicates that the NAD has been hydrolyzed . The structure has been compared with the catalytic domain of the diphtheria toxin, which was crystallized with ApUp.

Presse Med, 1995 Sep 2-9, 24(25), 1164 - 6
{Pseudomonas aeruginosa septicemia . Host-related risk factors in 82 episodes}; Roche O et al.; OBJECTIVES: The prognosis of septicaemia due to Pseudomonas aeruginosa is severe with mortality ranging from 32 to 73% . We retrospectively studied 82 episodes in order to determine whether risk factors could be identified . METHODS: Eighty-two episodes of Pseudomonas aeruginosa septicaemia, observed between 1986 and 1991, were analyzed . Risk of death within 2 days of the first positive blood culture (mortality = 19.5%) were assessed with univariate and multivariate analyses . RESULTS: Patient age ranged from 1 to 92 years . Most had been hospitalized in medical wards (49%) or intensive care units (28%) (NS) . The type of septicaemia (several bacteria in 21%), the source of the infection (nosocomial in 78%), portal, predisposing factors (cancer, haematologic disease: 54%) and MacCabe index were not significantly correlated with risk of death at two days following first positive blood culture . With univariate analysis body temperature below 38,5 degrees C was significant (p = 0.007) for death at day 2 and appropriate antibiotic treatment after diagnosis was significant (p < 0.001) for absence of death on day 2 . For multivariate analysis, chemotherapy and shock syndrome were significant (p = 0.005 and 0.09 respectively) for death at day 2 and appropriate antibiotic treatment was significant (p = 0.005) for absence of death on day 2 . CONCLUSION: Antibiotic prescription appears to be the most easily controlled significant factor predictive of outcome in Pseudomonas aeruginosa septicaemia.

J Commun Dis, 1995 Sep, 27(3), 151 - 4
Antibiotic sensitivity of isolates of Pseudomonas aeruginosa in Buraidah, Saudi Arabia; Ahmad S et al.; A study was carried out to determine the pattern of in vitro antibiotic sensitivity of a cross section of the isolates of Pseudomonas aeruginosa recovered from diverse clinical sources during a one year period . One hundred and eighty-six isolates were investigated by disc diffusion method employing multidiscs . Majority of the isolates were sensitive to amikacin (89.7%), tobramycin (75.81%), norfloxacin (68.48%), piperacillin (68.25%), and ceftazidime (58.81%) . Other antibiotics were effective for a lesser number of isolates . A few isolates were simultaneously resistant to several antibiotics, viz . gentamicin, carbenicillin, tobramycin, ceftazidime and augmentin . The significance of the findings is discussed.

J Antimicrob Chemother, 1995 Sep, 36(3), 463 - 73
Use of ultrasound to facilitate antibiotic diffusion through Pseudomonas aeruginosa alginate; Williams KA et al.; The effect of ultrasonic treatment of two pseudomonal alginate samples was studied by investigation of their rheological characteristics and interaction with tobramycin, piperacillin and ciprofloxacin . Whilst exposure to ultrasound at an amplitude of 20 microns for 8 min caused a significant decrease in viscosity of both alginates, molecular fragmentation, as demonstrated by PAGE and gel-permeation chromatography, was minimal . Antibiotic penetration was improved substantially however with sonication, leading to a 100% increase in tobramycin and piperacillin diffusion from the alginate compared with an untreated control polymer.

Afr J Med Med Sci, 1995 Sep, 24(3), 275 - 81
Effect of subminimum inhibitory concentration of ceftriaxone on adherence of Pseudomonas aeruginosa to inert surfaces in an experimental model; Onaolapo JA et al.; The effect of subminimum inhibitory concentration (subMIC) of ceftriaxone on adherence of two isolates of Pseudomonas aeruginosa onto inert surfaces (catheter, plastic and glass) was studied . It was found that the phase of growth of Ps . aeruginosa and the nature of the inert surfaces affected the adherence . One-twenty fourth of the M.I.C . increased the adherence of the clinical isolate in the exponential phase of growth but decreased it during the stationary phase; the reverse was the case for the wild type isolate . When the inert surfaces were coated with serum, the adherence of the clinical isolate also increased during the exponential phase of growth, while that of the wild type increased in the stationary phase . Changes in the surface properties of the test organisms indicated that the subMIC of Ceftriaxone mediated increase in hydrophobicity at both phases of growth . These results suggest that sub-inhibitory levels of Ceftriaxone may decrease the virulence of P . aeruginosa since a good polymorphnuclear leucocytebacterium contact will result in the bacterium being strongly phagocytosed because adherence has also been implicated in the process of phagocytosis.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1995 Sep, 11(5), 332 - 4
{Assessment of effectiveness of AgSD-ZnSD-Azone cream, negative ion irradiation and "moisture burn ointment" in prevention of burn wound infection as judged by changes in LPS, TNF and ET levels}; Sun S et al.; 40 Wistar rats were scalded resulting in 15% TBSA full-thickness burn . Pseudomonas aeruginosa (10(9)/ml) was seeded on the wounds . The animals were divided into 4 groups . AgSD and ZnSD (with Azone) cream was applied to the wounds in the group I . The wounds were irradiated with negative ion current in the group II . The "moisture burn ointment" was applied to the wounds in the group III . Group IV consisted of controls without any treatment . Judging by changes in levels of LPS, TNF and ET, it was shown that the best result was obtained in the group I and II . The "moisture burn ointment" group yielded the poorest results.

Zhonghua Zheng Xing Shao Shang Wai Ke Za Zhi, 1995 Sep, 11(5), 330 - 1
{Preliminary study on multi-resistant gene location of 20 strains of Pseudomonas aeruginosa}; Jia C et al.; 20 strains of Pseudomonas aeruginosa were isolated from burn patients of Xijing Hospital in Xi'an . These 20 strains which showed resistance to multiple antibiotics were selected to be studied regarding the location of multi-resistant gene . According to the sensitivity tests before and after plasmid removal, we found that in 70% of the bacteria resistance to multiple antibiotics was mediated by the plasmid . In 30% the bacteria remained resistant to antibiotics after plasmids were removed . Two explanations were postulated . (1) plasmids were not removed completely; (2) resistance gene was encoded by the chromosomes.

J Biochem (Tokyo), 1995 Sep, 118(3), 474 - 9
Crystal structure of the unliganded alkaline protease from Pseudomonas aeruginosa IFO3080 and its conformational changes on ligand binding; Miyatake H et al.; The crystal structure of the unliganded alkaline protease from Pseudomonas aeruginosa IFO3080 has been determined at 2.0 A resolution by the X-ray method . The enzyme consists of N-terminal catalytic and C-terminal beta-helix domains . On structural comparison between the present unliganded enzyme and structurally- known liganded enzyme, some structural changes were observed around the active site . In the unliganded enzyme, Y216 serves as the fifth ligand for the active site zinc ion . On ligand binding, Y216 may move to form a hydrogen-bond with the carbonyl oxygen of the P1 residue of a ligand peptide . D191 in the flexible loop, Y190 to D196, over the active site cleft forms hydrogen-bonds with the backbone atoms of the P1 and P2 residues of the ligand to close the entrance to the cleft . The water molecule which is the fourth ligand for the zinc ion is replaced by the carbonyl oxygen of the P1 residue . These structural changes around the active site may reflect the substrate-binding mode during the enzymatic reaction.

S Afr J Surg, 1995 Sep, 33(3), 128 - 30
Ruptured hepatic hydatid cyst and an unusual case of pseudomonas septicaemia; Fulton JO; Pseudomonas aeruginosa is a very rare cause of septicaemia in adults without significant underlying disease . A case of pseudomonas septicaemia occurring as a complication of a ruptured hydatid cyst in an apparently healthy young soldier is presented . This patient also had unusual pulmonary sequelae resembling pulmonary metastases together with massive haemoptysis.

Pediatr Pathol Lab Med, 1995 Sep-Oct, 15(5), 707 - 21
Immunohistologic quantification of Pseudomonas aeruginosa in the tracheobronchial tree from patients with cystic fibrosis; Potts SB et al.; Pseudomonas aeruginosa has been recognized as a pathogen of major importance in the patient with cystic fibrosis (CF) . However, no information is available regarding the histologic quantification of P . aeruginosa organisms in the CF tracheobronchial tree . We retrieved all formalin-fixed paraffin-embedded lung blocks from 20 consecutive autopsies of cystic fibrosis patients . Serial histologic sections were made and stained by three methods: hematoxylin and eosin, immunoperoxidase with anti-P . aeruginosa rabbit serum as the primary antibody, and immunoperoxidase with normal rabbit serum as the primary antibody . By studying the hematoxylin and eosin section, we classified five areas in the lung as bronchi, large bronchioles, small bronchioles, bronchioloectatic areas, and abscess/airways with destroyed epithelium . The areas stained by an anti-P . aeruginosa immunoperoxidase method were examined under high-power magnification, and the bacteria within random fields were counted . Pseudomonas aeruginosa organisms were identified in 14 of 20 cases, including 13 of 16 cases in which P . aeruginosa was specifically cultured at autopsy . Quantification of organisms within the lumens of all five airway types showed that the bacterial density in cystic fibrosis airways is highest in bronchi.

Mol Microbiol, 1995 Sep, 17(5), 935 - 43
Regulation of nucleoside diphosphate kinase and an alternative kinase in Escherichia coli: role of the sspA and rnk genes in nucleoside triphosphate formation; Shankar S et al.; We have previously reported that two genes cloned from a cosmid library of Escherichia coli can restore mucoidy to an algR2 mutant of Pseudomonas aeruginosa . AlgR2 is a protein involved in the regulation of nucleoside diphosphate kinase (Ndk) as well as alginate synthesis in P . aeruginosa . One of the E . coli genes, rnk, encodes a 14.9 kDa protein with no homology to any other proteins . The other gene, sspA, encodes the stringent starvation protein, a regulatory protein involved in stationary-phase regulation and the stringent response of E . coli . While both rnk and sspA restored alginate production to the P . aeruginosa algR2 mutant, only rnk restored Ndk activity to the mutant . In this report, we have examined the effect of mutations in rnk and sspA on the levels of Ndk in E . coli . We find that a mutation in rnk drastically reduces the level of Ndk in E . coli . A mutation in sspA, however, affects the level of another nucleoside diphosphate kinase distinct from Ndk . The proteins can be easily distinguished from each other by their different affinities for nucleoside diphosphates (NDPs) and also by the differential effect of anti-Ndk antibodies on the reactions they catalyse . The ability of either of these two proteins to restore alginate synthesis in the algR2 mutant of P . aeruginosa demonstrates the importance of nucleoside triphosphate synthesis and energy metabolism for alginate synthesis . Additionally, a role for the stringent starvation protein (SspA) in the modulation of nucleoside triphosphate (NTP) levels in E . coli is also suggested from these experiments.

Shock, 1995 Sep, 4(3), 216 - 24
Effect of recombinant human granulocyte colony-stimulating factor on hemodynamic and cytokine response in a porcine model of Pseudomonas sepsis; Haberstroh J et al.; To investigate the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on sepsis, chronically catheterized conscious pigs were challenged with Pseudomonas aeruginosa (8 x 10(7) colony-forming units kg-1 h-1) for 84 h (Group A, n = 8) . Group B (n = 7) also received rhG-CSF at 5 micrograms kg-1 d-1, the first dose being given 30 min before starting bacterial infusion . Two of the animals in Group A died from pulmonary failure, whereas all those treated with rh-GCSF survived . Fever, severe pulmonary hypertension and systemic hypotension--the latter accompanied at first by a transient hypodynamic, and later a hyperdynamic response--were observed in all of the animals . In Group B, however, the rise in temperature, mean pulmonary arterial pressure (at a later stage of the observation), plasma levels of tumor necrosis factor, and endotoxin were significantly less than in Group A . In the rhG-CSF-treated pigs, an initial leukopenia completely recovered within 24 h (p < .05 vs . Group A) . These data suggest that rhG-CSF might be beneficial in the treatment of sepsis.

Eur J Gastroenterol Hepatol, 1995 Sep, 7(9), 841 - 5
Antibiotic prophylaxis for ERCP: a randomized clinical trial comparing ciprofloxacin and cefuroxime in 200 patients at high risk of cholangitis; Mehal WZ et al.; OBJECTIVE: To compare the efficacy and safety of oral ciprofloxacin and intravenous cefuroxime in patients at high risk of cholangitis after endoscopic retrograde cholangiopancreatography (ERCP) . DESIGN: Prospective, randomized study . SETTING: A primary and tertiary referral centre . PATIENTS: A series of 232 consecutive patients who either had radiological evidence of biliary obstruction or were aged over 70 years were randomly assigned to receive either oral ciprofloxacin or intravenous cefuroxime before and after ERCP . Two-hundred and nine patients finished the study, with 23 being excluded because of withdrawal of consent or incomplete ERCP . INTERVENTIONS: Patients underwent ERCP: blood samples were taken for culture, full blood count and biochemistry before and after the procedure . Clinical follow-up was carried out 7 and 42 days after ERCP . MAIN OUTCOME MEASURES: Clinical, bacteriological or biochemical evidence of cholangitis, septicaemia or adverse drug reactions, and the cost of both protocols . RESULTS: Follow-up was recorded in all 209 patients who completed the study . By 42 days after ERCP, three patients had died (cholangiocancer, pancreatic cancer and renal failure) . Cholangitis was diagnosed in one patient from each of the two trial groups . Blood cultures from the patient on ciprofloxacin gave negative results, but a post-ERCP blood sample from the patient on cefuroxime grew Pseudomonas aeruginosa, which was sensitive to ciprofloxacin . There were no serious side-effects in either study group, but two patients assigned to ciprofloxacin became too nauseous to take the medication . The cost of the cefuroxime protocol was l7.56 pounds per patient, compared with 4.76 pounds per patient for the ciprofloxacin protocol . CONCLUSION: A pre- and post-ERCP oral ciprofloxacin regime is safe and provides effective prophylaxis against ERCP-induced cholangitis and septicaemia in high-risk patients . It is also more economical than a regime of intravenous cefuroxime and does not require nursing staff with training in intravenous techniques.

Burns, 1995 Sep, 21(6), 441 - 4
Studies on multiple Pseudomonas aeruginosa isolates from individual burn patients by RFLP, O antigen serotyping and antibiogram analysis; Holder IA et al.; Multiple isolates of Pseud . aeruginosa from individual burn patients were tested for antibiotic susceptibility-resistance patterns (antibiogram), O serotype lipopolysaccharide and chromosomal DNA restriction fragment length polymorphisms (RFLP) using a PAK pilin gene probe . Some patients were colonized by isolates identical by all three analytical procedures whereas other patients were found where multiple isolates were identical on the basis of serotype and antibiogram analysis, but different on the basis of RFLP analysis . Examples were found where multiple isolates from an individual patient appeared to be identical on the basis of serotyping and RFLP data, but different on the basis of antibiogram . Strains refractory to O serotyping could be characterized by RFLP type . These results indicate that RFLP analysis provides a valuable addition to routine serotyping and antibiogram studies on Pseud . aeruginosa isolates and that significant numbers of burn patients become co-colonized/co-infected with phenotypically diverse strains of this organism.

Clin Diagn Lab Immunol, 1995 Sep, 2(5), 554 - 62
Prevalence of gca, a gene involved in synthesis of A-band common antigen polysaccharide in Pseudomonas aeruginosa; Currie HL et al.; Two distinct forms of lipopolysaccharide are expressed by Pseudomonas aeruginosa . These forms are known as the A band and the B band . In an attempt to obtain a better understanding of A-band lipopolysaccharide synthesis, a previously isolated A-band gene known as the gca gene (GDP-D-mannose conversion protein for A-band common antigen polysaccharide) was sequenced and analyzed . Previous protein expression data from our laboratory, along with nucleotide sequence analysis from the present study, suggest that the Gca protein is encoded by the open reading frame ORF36.5 . Amino acid homology reveals that this protein may be functioning as a dehydratase or as a bifunctional enzyme, facilitating the conversion of GDP-D-mannose to GDP-D-rhamnose . The distribution of this gca gene among the 20 P . aeruginosa O serotypes, clinical isolates, and other Pseudomonas species was also examined . Southern hybridization results revealed that the gca gene is present and conserved on a 1.6-kb KpnI fragment among all 20 O serotypes with the exception of serotype O12 . In addition, the gca gene is not universally found among all pseudomonads; however, probe-reactive profiles are similar to that of P . aeruginosa when the gca gene is present . Primers were designed from the gca nucleotide sequence, and PCR amplification of a 700-bp product was found with each of the 20 O serotypes . Because of the conservation of this gene, gca may be useful as a diagnostic tool for detecting the presence of P . aeruginosa as well as other Pseudomonas species.

Antimicrob Agents Chemother, 1995 Sep, 39(9), 1970 - 2
DNA gyrase gyrA mutations in quinolone-resistant clinical isolates of Pseudomonas aeruginosa; Yonezawa M et al.; The mutations in the quinolone resistance-determining region of the gyrA gene from clinical isolates of Pseudomonas aeruginosa were determined by DNA sequencing . The strains were isolated in 1989 and 1993 . No mutations were detected in the clinical isolates in 1989, while five types of mutations were identified in the isolates in 1993 . These mutations were as follows: group 1, a Thr residue to an Ile residue at position 83 (Thr-83-Ile); group 2, Asp-87-Asn; group 3, Thr-83-Ile and Asp-87-Gly; group 4, Thr-83-Ile and Asp-87-Asn; group 5, Thr-83-Ile and Asp-87-His . Three types of double mutations (groups 3, 4, and 5) have not been described previously . These mutations were homologous to the Ser-83-Leu, Asp-87-Asn, and Asp-87-Gly changes observed in Escherichia coli . Thus, DNA gyrase A subunit mutations are implicated in resistance to quinolones in P . aeruginosa as well as E . coli.

Antimicrob Agents Chemother, 1995 Sep, 39(9), 1948 - 53
Role of mexA-mexB-oprM in antibiotic efflux in Pseudomonas aeruginosa; Li XZ et al.; We have earlier described mexA-mexB-oprK, an operon involved in pyoverdine export in Pseudomonas aeruginosa, and suggested that the products of these genes also contribute to the active efflux of several antibiotics (K . Poole, K . Krebes, C . McNally, and S . Neshat, J . Bacteriol . 175:7363-7372, 1993) . Recently the outer membrane component of this efflux system was shown to be OprM, rather than OprK (N . Gotoh and K . Poole, unpublished results) . In the present study, the conclusion concerning the efflux activity of this system was confirmed and extended by the measurement of drug accumulation in intact cells . Thus, the steady-state accumulation levels of tetracycline and norfloxacin were increased in mexA and oprM null mutants . mexA and oprM null mutants also showed an increase in susceptibility to a wide variety of beta-lactam antibiotics and an increase in the steady-state accumulation level of benzylpenicillin, indicating that the MexA-MexB-OprM pump also effluxes beta-lactams . Furthermore, deenergization of the cytoplasmic membrane with a proton conductor always produced a strong increase in the accumulation level . Finally, a single-step mutant over-producing MexAB-OprM accumulated less tetracycline and chloramphenicol than the parent strain and was more resistant to a wide range of antimicrobial compounds, including beta-lactams . These results support the notion that these proteins contribute to the intrinsic resistance of P . aeruginosa through the multidrug active efflux process.

Optom Vis Sci, 1995 Sep, 72(9), 643 - 8
Ultrastructural visualization of lectin receptors in normal and injured epithelium of the rabbit cornea; Latkovic S et al.; Lectin receptors of the rabbit corneal epithelium were investigated ultrastructurally using gold-conjugated lectins . Corneal epithelium with an intact mucous layer was readily labeled with wheat-germ agglutinin (WGA), whereas after mechanical or chemical removal of the mucus, labeling was minimal, suggesting that the lectin receptors were located mainly in the mucus . Corneal epithelium subjected to slight superficial injury was also labeled with WGA . In this case, however, the gold particles were in close contact with the cell membrane of injured and/or newly exposed cells . In the more injured cells, gold particles were seen in the cytoplasm as well . Labeling with WGA indicates the presence of sialyl residues, known to be attachment sites for Pseudomonas aeruginosa . The results suggest a protective role of mucus against infection . The association of WGA lectin receptors with the plasma membrane of compromised corneal epithelial cells may help to explain the mechanism of bacterial invasion of the cornea, e.g., in overnight wear of contact lenses with insufficient oxygen transmissibility.

Zh Mikrobiol Epidemiol Immunobiol, 1995 Sep-Oct, (5), 13 - 5
{The epidemiological markers of Pseudomonas aeruginosa strains circulating in different types of hospitals}; Makarova NV et al.; Pyocinovar and serovar characteristics of 91 P.aeruginosa strains isolated from patients and the environment in a hospital for premature children, a child survey hospital and a neonatological hospital . The leading epidemiological markers of P.aeruginosa strains, among them pyocinovar 883722, serovar 6 (a hospital for premature children), pyocinovar 888888, serovar 4 (a child surgery hospital), pyocinovars 888888 and 861322 (a neonatological hospital).

Drugs, 1995 Sep, 50(3), 423 - 39
Drug utilisation review (DUR) of the third generation cephalosporins . Focus on ceftriaxone, ceftazidime and cefotaxime; Adu A et al.; Six parenteral third generation cephalosporins have been introduced into clinical use in the past 10 years . The 3 most frequently available agents are cefotaxime, ceftriaxone and ceftazidime . These 3 third generation cephalosporins are characterised by a broad spectrum of activity and increased stability to beta-lactamases compared with the first and second generation cephalosporins . However, there are growing numbers of reports of resistance to these agents with increasing use . The major differences in the properties of the 3 agents are the long half-life of ceftriaxone and its dual route of elimination . Ceftazidime is best restricted to Pseudomonas aeruginosa infections where other agents are contraindicated or ineffective . Cefotaxime and ceftriaxone can be used in nosocomial Gram-negative infections where P . aeruginosa can be ruled out . The types and incidences of adverse drug reactions are not different for the 3 agents . A number of drug utilisation review (DUR) studies of these agents in the hospital setting have reported a considerable incidence of inappropriate use and substantial avoidable costs . There are methodological problems with most of the DUR studies, especially the criteria and the methods of cost estimation . The use of pharmacoeconomic methodology could ensure more realistic cost estimation; however, outcome data are, in most cases, not available.

Chemotherapy, 1995 Sep-Oct, 41(5), 334 - 6
Comparison of imipenem and five other antipseudomonal agents against gentamicin-susceptible and -resistant Pseudomonas aeruginosa; Gerceker AA et al.; The in vitro activities of imipenem, aztreonam, piperacillin, ciprofloxacin and amikacin were tested by the microbroth dilution technique against 86 clinical isolates of Pseudomonas aeruginosa . Imipenem and ciprofloxacin were the most active agents against gentamicin-susceptible P . aeruginosa . Only imipenem inhibited gentamicin-resistant P . aeruginosa at < or = 8 micrograms/ml . The finding that none of the gentamicin-resistant strains were resistant to imipenem and amikacin indicated the superiority of these antibiotics to the other agents in hospital-associated gentamicin-resistant P . aeruginosa infections.

Chemotherapy, 1995 Sep-Oct, 41(5), 323 - 9
Comparative serum bactericidal activity against Pseudomonas aeruginosa of six antipseudomonal agents; Dan M et al.; Serum levels and serum bactericidal activities of six antipseudomonal agents were studied comparatively in 60 patients . Single intravenous doses of gentamicin (1.5 mg/kg), piperacillin (4 g), ceftazidime (1 g), imipenem (0.5 g), aztreonam (1 g), and ciprofloxacin (200 mg) were given over 30 min to 10 patients each, and serum samples were obtained 30 min, 1, 2, 3, 4, 6, 8 and 12 h after beginning the infusion . Serum bactericidal activity was determined by the broth microdilution method against 10 recent isolates of Pseudomonas aeruginosa . Mean peak serum levels were as follows: gentamicin 10.4 micrograms/ml, piperacillin 227.5 micrograms/ml, ceftazidime 43.5 micrograms/ml, imipenem 17.3 micrograms/ml, aztreonam 42.3 micrograms/ml, and ciprofloxacin 3.9 micrograms/ml . All agents demonstrated effective serum bactericidal activity (geometric mean titer > 1:2) at peak serum levels . Ceftazidime was by far the most potent compound with a mean titer of 1:46.5, followed by ciprofloxacin (1:17), imipenem (1:13.7), and aztreonam (1:13.4) . Ceftazidime also showed the longest duration of activity with a mean titer of 1:5.1 at 4 h . Based on our results, ceftazidime appeared to be the most potent antipseudomonal agent, while gentamicin and piperacillin were the least effective.

Trends Microbiol, 1995 Sep, 3(9), 351 - 6
Pseudomonas aeruginosa, mucoidy and the chronic infection phenotype in cystic fibrosis; Deretic V et al.; During chronic infections in cystic fibrosis, persistence of Pseudomonas aeruginosa is associated with conversion into forms that are associated with conversion into forms that are characterized by a mucoid colony morphology, rough lipopolysaccharide and, paradoxically, decreased systemic virulence . The mutations underlying these changes occur in global regulators, such as alternative sigma factors and their accessory elements.

Am J Respir Crit Care Med, 1995 Sep, 152(3), 921 - 6
Cytokines affect pseudomonas binding to tracheal cells via a neutrophil-mediated process; Raoof S et al.; Critical illness is often associated with gram-negative bacterial colonization of the airways, increasing the risk of nosocomial pneumonia . Cytokines, released in response to endotoxin, might contribute to this phenomenon by causing changes in epithelial cell binding of bacteria . To investigate this possibility, human monocytes and hamster pulmonary macrophages were cultured without or with Escherichia coli endotoxin (10 micrograms/ml) for 4 and 24 h . Hamster and human tracheal epithelial cells were treated with supernates from monocyte cultures for 24 h, and subsequent binding of 14C-labeled Pseudomonas aeruginosa to the epithelial cells was measured (percent adherence) . In separate experiments, recombinant human (rh) tumor necrosis factor-alpha (TNF-alpha) (25 to 100 ng/ml) and interleukin-1 beta (IL-1 beta) (2,000 to 8,000 pg/ml) were added to hamster monolayers . Neither monocyte supernates nor purified cytokines were toxic to the epithelial cells for up to 48 h . There was no significant change in P . aeruginosa adherence to either hamster or human tracheal epithelial cells after 24 h of exposure to culture supernates from either endotoxin-stimulated human monocytes or hamster macrophages . Similarly, purified rhTNF and rhIL-1 exposure did not increase bacterial adherence . However, when polymorphonuclear leukocytes were coincubated with the monocyte supernates and epithelial cells, P . aeruginosa adherence was significantly increased . Moreover, this effect was enhanced by an epithelial cell-derived substance . Thus, while inflammatory cytokines may participate in enhancing bacterial colonization of the lung in vivo, they do not do so by a direct action on tracheal epithelial cells but can act via a neutrophil-dependent mechanism.

J Med Microbiol, 1995 Sep, 43(3), 169 - 75
Role of exotoxin A in inducing severe Pseudomonas aeruginosa infections in mice; Miyazaki S et al.; The effects of exotoxin A (EXA) from Pseudomonas aeruginosa on polymorphonuclear leucocytes (PMNLs) were studied in a mouse model and in vitro . P . aeruginosa PA103, which produced EXA, was 20 times more virulent for normal mice than was its EXA-deficient mutant, PA103-29 . EXA was detected in the plasma of mice infected with P . aeruginosa PA103, and its presence correlated with increasing numbers of bacteria in the blood and internal organs . A monoclonal antibody (MAb) against EXA prevented the death of the mice if it was given simultaneously with, or 2 h before, infection with strain PA103 . The number of PMNLs in murine blood decreased by 50% within 30 min of intravenous injection of EXA, but this decrease was prevented by simultaneous or prior injection of MAb to the toxin . EXA inhibited in-vitro phagocytosis and killing of P . aeruginosa by human and murine PMNLs and decreased the number of the PMNLs by between 60 and 68% . Collectively, these results not only confirm that EXA is toxic in vivo, but also suggest that this toxin accelerates the growth of virulent P . aeruginosa in mice.

Arch Otolaryngol Head Neck Surg, 1995 Sep, 121(9), 1022 - 5
Therapeutic implications in the treatment of aural Pseudomonas infections based on in vitro susceptibility patterns; Dohar JE et al.; OBJECTIVE: To examine the in vitro susceptibility patterns of aural isolates of Pseudomonas aeruginosa and to identify changes over a 4-year period . DESIGN: Retrospective case series . SETTING: The outpatient department at Children's Hospital of Pittsburgh (Pa), a tertiary referral center . PATIENTS: Ambulatory children younger than 18 years from whose ears P aeruginosa was isolated . OUTCOME MEASURES: The in vitro susceptibility of aural isolates of P aeruginosa to ampicillin, cefotaxime, chloramphenicol, sulfisoxazole, ticarcillin, mezlocillin, gentamicin, tobramycin, cefazolin, tetracycline, piperacillin, nitrofurantoin, cephalexin hydrochloride, ceftriaxone, cefuroxime axetil, and sulfamethoxazole-trimethoprim . RESULTS AND CONCLUSIONS: No changes were found in the trends of the susceptibility patterns over the 4-year study period, with the exception of the semisynthetic penicillins, ticarcillin and mezlocillin . These two agents were found to be relatively ineffective against the strains of P aeruginosa isolated in 1989 (59% and 18% susceptibility, respectively) . This finding is in contrast to their effectiveness over the remainder of the study period (96% and 90% susceptibility, respectively), which was excellent . These observations likely reflect a change in the breakpoints for the minimal inhibitory concentrations between these periods . The intravenous agent with the best susceptibility profile was piperacillin (96%) . Of the aminoglycosides tested, 94% of the isolates were sensitive to tobramycin, as opposed to only 79% for gentamicin . This finding may have significance when one is empirically selecting ototopical therapy, since both tobramycin and gentamicin are available as topical preparations . Of the oral agents, the combination of sulfamethoxazole-trimethoprim was most effective (46%).

Infect Immun, 1995 Sep, 63(9), 3497 - 501
Rapid and sensitive method for evaluating Pseudomonas aeruginosa virulence factors during corneal infections in mice; Preston MJ et al.; A murine corneal scratch model has been used extensively to study various aspects of the pathogenesis of Pseudomonas aeruginosa, a common etiologic agent of corneal infections . This model uses mild inhalation anesthetics which keep the animals immobile for a relatively short time and promote the interaction between the infecting organisms and the corneal wound . Under these circumstances, only a small number of P . aeruginosa isolates delivered at inocula of > 10(7) CFU are infectious . We determined that this model is useful for studying other P . aeruginosa strains given at lower doses if injectable anesthetics are administered prior to infection to keep the animals immobile for 15 to 30 min . Under these conditions, eight clinical isolates of P . aeruginosa tested at doses of 10(8) CFU per eye induced corneal perforation and/or phthisis in C3H/HeN mice . The 50% infective doses of several strains were between 3 x 10(2) and 1 x 10(5) CFU per mouse eye . When this modified anesthetic procedure was used to evaluate the roles of different P . aeruginosa virulence factors in eye infections, pathology was not observed when eyes were inoculated with 10(8) CFU of strains deficient in production of a complete lipopolysaccharide or the RpoN sigma factor . A strain with a point mutation in the fur gene, involved in production of iron-regulated factors, showed decreased virulence, while a mutant deficient in both hemolytic and nonhemolytic phospholipase C was fully virulent . By modifying the anesthesia procedure, the corneal scratch model allows rapid evaluations of the roles of P . aeruginosa virulence factors in corneal infections.

Infect Immun, 1995 Sep, 63(9), 3272 - 8
Role of tumor necrosis factor alpha in innate resistance to mouse pulmonary infection with Pseudomonas aeruginosa; Gosselin D et al.; In the present study, we have investigated the mechanisms underlying mouse resistance to endobronchial infection with Pseudomonas aeruginosa enmeshed in agar beads . This was done by monitoring macrophage activation-associated gene expression in lung and alveolar cells harvested from resistant (BALB/c) and susceptible (DBA/2, C57BL/6, and A/J) strains of mice over the course of infection with P . aeruginosa . Interleukin-1 alpha, interleukin-1 beta, macrophage inflammatory protein-1 alpha, JE, and tumor necrosis factor alpha (TNF-alpha) mRNA expression levels were up-regulated in all strains of mice during the early phase of the infection . The level of TNF-alpha mRNA expression was increased to a greater extent in resistant BALB/c mice than in susceptible DBA/2, C57BL/6, and A/J strains of mice . This observation paralleled a higher secretion of TNF-alpha into the alveolar space of BALB/c mice at 3 and 6 h postinfection . The concentration of TNF-alpha released in alveoli returned to basal levels within 24 h of infection in mice of all strains, even though the TNF-alpha mRNA expression remained high until 3 days after infection . In vivo treatments with either anti-murine TNF-alpha monoclonal antibodies or with aminoguanidine significantly increased the number of P . aeruginosa bacteria detected in the lungs of resistant mice at 3 days postinfection . Overall, these findings indicate that both TNF-alpha and nitric oxide exert a protective role in response to pulmonary infection with P . aeruginosa.

Chem Pharm Bull (Tokyo), 1995 Sep, 43(9), 1441 - 7
Syntheses of three interglycosidic isomers of N-acetyl-beta-D-mannosaminyl-L-rhamnoses associated with O-antigens of several gram-negative opportunistic pathogens; Kaji E et al.; We achieved practical, highly stereoselective syntheses of three interglycosidic isomers of N-acetyl-beta-D-mannosaminyl-L-rhamnoses, among which a beta(1-->4)-isomer corresponds to the repeating unit of the O-antigen of lipopolysaccharide (LPS) from the opportunistic pathogens Pseudomonas cepacia O5 and Pseudomonas aeruginosa X (Meitert) . The other isomers are a beta(1-->2)-disaccharide, a constituent of LPS from Escherichia coli O1A, and an artificial beta(1-->3)-isomer . The disaccharides were obtained by simple three-step reaction sequences from 2-(benzoyloxyimino)-2-deoxyglycosyl halides (mannosamine progenitor) . beta-Selective glycosylations of appropriately protected L-rhamnosyl acceptors were performed . Subsequent reduction of the 2-acyloxyimino function to an amino group, N-acetylation, and removal of the protecting groups provided the target disaccharides . 13C-NMR and nuclear Overhauser effect spectra proved to be useful for structural determination of the positional isomers of the disaccharides.

Nat Med, 1995 Sep, 1(9), 956 - 8
Resistance of microorganisms to disinfection in dental and medical devices; Lewis DL et al.; The U.S . Centers for Disease Control and Prevention (CDC) recommends that only heat sterilization be used for all reusable devices entering the oral cavity . However, chemical disinfection is still employed for reprocessing dental devices in many areas of the world . In an analysis of a Florida dental practice responsible for nosocomial human immunodeficiency virus (HIV) transmissions, the possible role of contaminated devices was deemed unlikely in part because they were subjected to high-level disinfection with 2% glutaraldehyde . Disease transmissions have, however, been documented for endoscopes used in diagnostic and surgical procedures even after this treatment . In some dental devices, lubricants mix with potentially infectious patient materials, and organic debris has been observed in endoscopes after cleaning . We have investigated whether lubricants can render high-level chemical disinfection procedures ineffective and have addressed the role that some common devices may play in disease transmission . We report here that HIV in whole-blood samples and Pseudomonas aeruginosa in blood and plasma survived high-level disinfection when entrapped in lubricants used in dental handpieces and endoscopes . We also found that lubricated dental devices used to clean and polish teeth (prophylaxis angles) have the potential to transfer sufficient amounts of blood to infect human lymphocyte cultures with HIV . These results emphasize the need to subject reusable dental devices to a heat-sterilization protocol that penetrates the lubricant.

Lett Appl Microbiol, 1995 Sep, 21(3), 176 - 9
Enhanced biodegradation and emulsification of crude oil and hyperproduction of biosurfactants by a gamma ray-induced mutant of Pseudomonas aeruginosa; Iqbal S et al.; A gamma ray-induced mutant of Pseudomonas aeruginosa strain S8, capable of hyperproduction of biosurfactant from hydrocarbons, was isolated and named as EBN-8 . The mutant showed 3-4 times more hydrocarbon emulsification/conversion as compared to the parent when grown on Khaskheli crude oil in minimal medium . Enhanced biosurfactant production and hydrocarbon utilization by the mutant was also observed during growth on heptadecane in minimal medium as indicated by emulsion index and surface tension of cell-free culture broth . Using heptadecane as carbon and energy source, time course for the growth (cfu ml-1) and biosurfactant production were compared for both parent and mutant . These studies were carried out for 24 d at 30 +/- 2 degrees C and for 20 d at 37 degrees C . Growth of EBN-8 was much faster compared to the parent as well as being 2-3 times more hyperproductive.

Am J Physiol, 1995 Sep, 269(3 Pt 1), L388 - 93
Effects of sodium concentration on human neutrophil bactericidal functions; Mizgerd JP et al.; What are the ionic requirements for neutrophil (PMN) function and how might altered electrolyte concentrations contribute to airway disease? The in vitro killing of Pseudomonas aeruginosa by human peripheral white blood cells (WBCs) was progressively compromised Na+ concentration was lowered from 124 to 62 mM; at 62 mM Na+, bactericidal activity was 28.8 +/- 7.4% (SE) of normal . In contrast, Cl- concentration affected killing only when lowered to 8 mM . We examined phagocytosis and oxidative metabolism in response to P . aeruginosa or particles opsonized with either immunoglobulin G (IgG) or complement (C') . Phagocytosis of P . aeruginosa and of IgG-coated particles was Na(+)-dependent (31.2 +/- 3.1 and 58.6 +/- 14.2% of normal, respectively, at 62 mM Na+) . However, no effect on uptake of C'-coated particles was observed, and the respiratory burst at 70 mM Na+ was normal regardless of stimuli . Thus low Na+ concentration compromises select PMN functions . These results may help explain why airways of cystic fibrosis (CF) patients become colonized with bacteria such as P . aeruginosa . Perhaps the low concentration of Na+ reported for some CF respiratory secretions inhibits bactericidal functions of PMNs, predisposing these patients to airway infections.

J Med Assoc Thai, 1995 Sep, 78(9), 455 - 9
Ofloxacin otic solution as treatment of chronic suppurative otitis media and diffuse bacterial otitis externa; Sumitsawan Y et al.; Pseudomonas aeruginosa, Diphtheroid bacilli, Staphylococcus aureus were the major causes of diffuse bacteria otitis externa and chronic suppurative otitis media . This study showed that 0.3 per cent ofloxacin used for 2 weeks gave good clinical and bacteriological control of chronic suppurative otitis media and diffuse bacterial otitis externa without significant side effects.

J Bacteriol, 1995 Sep, 177(17), 4914 - 20
Insertion mutagenesis of the Pseudomonas aeruginosa phosphate-specific porin OprP; Sukhan A et al.; The gene encoding the Pseudomonas aeruginosa phosphate-specific porin OprP was subjected to both linker and epitope insertion mutageneses . Nine of the 13 linker mutant genes expressed protein at levels comparable to those obtained with the wild-type gene . These mutant proteins were shown, by indirect immunofluorescence with an OprP-specific antiserum, to be properly exposed at the cell surface . Four of the linker mutant genes expressed protein at reduced levels which were not detectable at the cell surface . A foreign epitope from the circumsporozoite form of the malarial parasite Plasmodium falciparum was cloned into the linker sites of 12 of the 13 mutant genes . Seven of the resultant epitope insertion mutant genes expressed surface-exposed protein . Two of these mutant genes presented the foreign epitope at surface-accessible regions as assessed by indirect immunofluorescence with a malarial epitope-specific monoclonal antibody . The data from these experiments were used to create a topological model of the OprP monomer.

Epidemiol Mikrobiol Imunol, 1995 Sep, 44(3), 115 - 7
{The effect of subinhibitory concentrations of norfloxacin, erythromycin and roxithromycin on Pseudomonas aeruginosa virulence factors}; Hostacka A; The effect of sub-MICs (1/4 MIC, 1/8 MIC, 1/16 MIC) of norfloxacin, erythromycin, roxithromycin on Pseudomonas aeruginosa virulence factors was studied . It was found that 1/4 of the MIC of norfloxacin inhibited most effectively elastase as well as proteinase activity (to 30.1% or 29.2% of the control values) . Macrolide antibiotics did not reduce the tested enzymic activities but caused their increase.

Kyobu Geka, 1995 Sep, 48(10), 836 - 40
{Combination therapy with arbekacin and fosfomycin against postoperative severe mixed-pneumonia of MRSA in primary lung cancer patients}; Harada R et al.; We experienced successful treatment of postoperative severe pneumonia of Methicillin-resistant Staphylococcus aureus (MRSA) with combination therapy of Arbekacin (ABK) and Fosfomycin (FOM) in three lung cancer patients . Case 1 was a advanced age of seventy-nine man who had had right upper lobectomy . Case 2 was a 61-year-old man who had had left lower lobectomy and extended bilateral mediastinal lymph-node dissection through the median sternotomy . And case 3 was a 59-year-old man who had suffered from pulmonary embolism after right pneumonectomy and partial resection of left atrium and superior vena cava . All cases were immuno-compromised patients and super-infected with Gram-negative rods, and Pseudomonas aeruginosa in case 1 and case 3 . Clinical symptoms were improved after the start of administration of ABK and FOM inspite of ineffectiveness of prior treatment with other antibiotics . We added staggered chemotherapy of Sulbactam/Cefoperazone (SBT/CPZ) and Ceftazidime (CAZ) for case 1 and case 3 respectively . Thus, the combination therapy of ABK and FOM might be useful for severe pneumonia of MRSA in the immunocompromised patients, and the combined staggered chemotherapy of beta-lactum agents and above would be the first choice in the treatment for the case involving Pseudomonas aeruginosa.

Biochem Biophys Res Commun, 1995 Aug 24, 213(3), 759 - 67
Regioselective dioxygenation of ortho-trifluoromethylbenzoate by Pseudomonas aeruginosa 142: evidence for 1,2-dioxygenation as a mechanism in ortho-halobenzoate dehalogenation; Selifonov SA et al.; Pseudomonas aeruginosa strain 142 oxidizes 2-halobenzoates via a multicomponent oxygenase (V . Romanov and R.P . Hausinger, J . Bacteriol., 1994, 176(11), 3368-3374) . The intermediacy of a highly unstable cis-diol in the reaction has been proposed . Direct evidence for this is currently lacking and the stereochemical course of the reaction cannot be inferred from previous studies . In this study, 2-trifluoromethylbenzoate was stoichiometrically oxidized by P . aeruginosa 142 to a chiral product identified as (-)2-trifluoromethyl-cis-1,2-dihydroxy-3,5-cyclohexadiene-1-carboxylic acid . These data rigorously establish a dioxygenative mechanism for 2-halobenzoate metabolism.

Biochim Biophys Acta, 1995 Aug 16, 1251(1), 48 - 54
Disruption of the disulfide bridge in azurin from Pseudomonas aeruginosa; Bonander N et al.; In the family of small blue-copper proteins azurins are unique in that they contain a disulfide bridge close to the amino-terminal end . It is situated in the 'south' side of the molecule, about 25 A away from the copper . Site-specific mutagenesis was used to exchange one or both of the cysteines in the bridge for serines in Pseudomonas aeruginosa azurin . In the double mutant Cys3Ser-Cys26Ser the Type 1 Cu is converted into Type 2, and the fluorescence of the single internal tryptophan shows that it becomes exposed to a polar environment . The circular dichroism spectrum indicates a loss of beta-structure . Thus, this mutation prevents the correct folding of the protein and the formation of the metal-binding site . Single mutants, Cys3Ser or Cys26Ser, can at least in part form native-like structures as shown by optical, EPR, fluorescence and CD spectroscopy . The Cys3Ser mutant can form a stable intermolecular disulfide bond which promotes the native conformation of the protein.

J Biotechnol, 1995 Aug 15, 42(1), 85 - 90
Estimation of kinetics of mercury detoxification from low-inoculum batch cultures of Pseudomonas aeruginosa PU21 (Rip64); Chang JS et al.; The growth rate of Pseudomonas aeruginosa PU21 (Rip64) and the mercury detoxification rate were determined by using low-inoculum batch cultures . In order to attain invariant culture conditions for the determination of growth kinetics in mercury-containing Pseudomonas minimal media (PMM), the initial cell concentrations were adjusted to approx . 100 cells per ml, and the initial mercury concentrations used were less than 2 micrograms Hg2+ per ml . It was found that the specific growth rate decreased as mercury concentration increased . The relationship between specific growth rate and glucose concentration was found to follow Monod kinetics . The mercury detoxification rate was determined for the viable cells and the dying (non-growing) cells.

Proc Natl Acad Sci U S A, 1995 Aug 15, 92(17), 7941 - 5
The algT (algU) gene of Pseudomonas aeruginosa, a key regulator involved in alginate biosynthesis, encodes an alternative sigma factor (sigma E); Hershberger CD et al.; Chronic infection by alginate-producing (mucoid) Pseudomonas aeruginosa is the leading cause of mortality among cystic fibrosis (CF) patients . During the course of sustained infection, the production of an alginate capsule protects the bacteria and allows them to persist in the CF lung . One of the key regulators of alginate synthesis is the algT (algU) gene encoding a putative alternative sigma factor (sigma E) . AlgT was hyperproduced and purified from Escherichia coli . The N-terminal sequence of the purified protein matched perfectly with that predicted from the DNA sequence . The purified protein, in the presence of E . coli RNA polymerase core enzyme, was able to initiate transcription of an algT promoter . Deletion of the -35 region of this promoter abolished this activity in vitro as well as in vivo . These data indicate that the algT gene encodes a sigma factor that is autoregulatory.

Gene, 1995 Aug 8, 161(1), 21 - 6
Identification of fimbrial assembly genes from Dichelobacter nodosus: evidence that fimP encodes the type-IV prepilin peptidase; Johnston JL et al.; Dichelobacter nodosus (Dn) is the causative agent of footrot, an economically significant disease of sheep . One of the factors believed to be involved in the virulence of this organism is its ability to produce type-IV fimbriae, which are the major protective antigens . To investigate the process of fimbrial biogenesis in Dn, gene probes were constructed from pilus biogenesis genes of Pseudomonas aeruginosa (Pa) and used to isolate homologues from Dn . A homologue, designated fimP, of the Pa prepilin peptidase-encoding gene, pilD, was cloned using this approach . The fimP gene product was shown to possess endopeptidase activity when produced in Escherichia coli . Two other fimbrial biogenesis genes fimN and fimO, whose products show similarity to the Pa PilB and PilC proteins, respectively, were identified because of their linkage to fimP . The arrangement of fimN, fimO and fimP in Dn closely resembles the arrangement of pilB, pilC and pilD in Pa.

Biochem Biophys Res Commun, 1995 Aug 4, 213(1), 88 - 95
Role of porins in the antibiotic susceptibility of Pseudomonas aeruginosa: construction of mutants with deletions in the multiple porin genes; Yoneyama H et al.; We inserted deletions in the chromosomal genes of Pseudomonas aeruginosa coded for the outer membrane porins, proteins C, D2, or E1, and all possible combinations of these proteins by the gene replacement technique and selecting for imipenem-resistance . Determination of the minimum inhibitory concentrations of beta-lactams, fluoroquinolones, chloramphenicol and gentamicin in these mutants revealed that most mutants showed equal susceptibility to the porin-sufficient strain . The only exception was that imipenem and meropenem showed increased minimum inhibitory concentrations in all of the mutants lacking protein D2 . These results firmly established that the P . aeruginosa porins identified so far form the pores do not accommodate the passage of most antipseudomonal antibiotics, with the exception of carbapenems.

Diagn Microbiol Infect Dis, 1995 Aug, 22(4), 331 - 6
Mechanism of amikacin resistance in Pseudomonas aeruginosa isolates from patients with cystic fibrosis; Hurley JC et al.; We studied 27 amikacin-resistant isolates of Pseudomonas aeruginosa from patients with cystic fibrosis to determine the mechanism of antibiotic resistance . The absence of aminoglycoside-modifying enzymes (AMEs) in these isolates was inferred from the failure of DNA probes for 16 candidate AMEs to hybridize with DNA harvested from these isolates and, in addition, the uniform reduction in susceptibility to a panel of aminoglycosides . In eight of the 27 isolates that were resistant to amikacin at high levels (minimum inhibitory concentration > or = 250 micrograms/ml), plasmids were not detected . The ribosomes of these isolates were sensitive to amikacin in studies of protein synthesis by cell "ghosts." These data suggest that impermeability is the mechanism of amikacin resistance in isolates of P . aeruginosa from patients with cystic fibrosis . Recognition of this mode of resistance may be difficult, as some isolates appeared to be borderline susceptible when tested against aminoglycosides other than amikacin, or had zone diameters that overlapped those obtained with amikacin-susceptible isolates.

Pediatr Pulmonol, 1995 Aug, 20(2), 71 - 7
High levels of complement-activation capacity in sera from patients with cystic fibrosis correlate with high levels of IgG3 antibodies to Pseudomonas aeruginosa antigens and poor lung function; Pressler T et al.; Heat-stable opsonins from sera of cystic fibrosis (CF) patients were investigated for their ability to activate complement . Complement activation by Pseudomonas aeruginosa after opsonization with patient serum was examined in a complement-consumption assay . Absorption of patients' sera with formalin-treated and boiled bacteria removed specific antibodies and the complement activation decreased . We found a positive correlation between serum complement-activation ability and IgG3 antibody levels to lipopolysaccharide (LPS), alginate, and a crude mixture of P . aeruginosa antigens (sonicate) in a group of patients with high levels of anti-Pseudomonas precipitins . In the same group of patients a significant negative correlation was found between complement activation and lung function . Eighteen patients have been followed longitudinally with serum samples covering the pre-infection, the early, and the late stages of chronic infection . Patients with poor lung function showed significantly higher levels of complement-activation capacity . We conclude that patients with high levels of specific IgG3 antibodies are able to induce a high level of complement activation and then develop more aggressive pulmonary tissue damage, probably secondary to local immune complex formation.

Clin Infect Dis, 1995 Aug, 21(2), 437 - 9
Pseudomonas aeruginosa folliculitis due to non-O:11 serogroups: acquisition through use of contaminated synthetic sponges; Maniatis AN et al.; We describe the features of 13 cases of Pseudomonas aeruginosa folliculitis (eight of which occurred sporadically and five of which resulted from two family outbreaks) that developed subsequent to the use of commercial synthetic sponges for bathing . On the basis of O serogrouping and pyocin typing and subtyping, the strains recovered from the skin lesions were found to be identical to those isolated from household shower water and sponges . P . aeruginosa folliculitis is commonly caused by the serogroup O:11; The serogroups described in this study are rare causative agents of this type of skin infection . We believe that this is the first report of P . aeruginosa folliculitis due to serogroups O:3 and O:16.

Clin Infect Dis, 1995 Aug, 21(2), 310 - 4
Lower respiratory tract infections following cardiac arrest and cardiopulmonary resuscitation; Rello J et al.; All episodes of lower respiratory tract infection that developed among 96 patients surviving for > 24 hours after cardiac arrest were prospectively studied over an 18-month period . Pneumonia developed in 23 (24.0%) of patients after a mean of 7 days (SD, +/- 6.2 days) . The development of four superinfections raised the cumulative incidence to 28.1% . Purulent tracheobronchitis was diagnosed in three instances . The causative agent of pneumonia was identified in 18 episodes, three of which were polymicrobial . Gram-positive cocci represented 57.1% of isolates, and Staphylococcus aureus--the most frequently isolated microorganism in this population--accounted for two-thirds of all gram-positive cocci . Pseudomonas aeruginosa was isolated in six episodes, five of which were associated with previous antibiotic use . Nine (39.1%) of the 23 patients in the group with pneumonia died, but only one of these deaths was considered to be directly related to pneumonia . In conclusion, pneumonia is a common complication of patients surviving cardiac arrest, but, with adequate treatment, its influence on outcome is marginal . Gram-positive cocci are the predominant pathogens, although infection with P . aeruginosa should be considered among patients receiving antibiotics.

Eur J Epidemiol, 1995 Aug, 11(4), 453 - 7
In vitro activity of commercially manufactured disinfectants against Pseudomonas aeruginosa; Orsi GB et al.; The in vitro activity of 17 commercially manufactured disinfectants routinely used in a large teaching hospital was tested against 128 strains of Pseudomonas aeruginosa isolated from hospitalized patients and the hospital environment . Except for quaternary ammonium salts, all the disinfectants at dilutions higher or equalling those recommended by the manufacturer were adequate to suppress P . aeruginosa . Chlorhexidine-, povidone-iodine- and glutaraldehyde-based disinfectants at dilutions 4 to 8-fold lower than the normal use dilution had a marked bactericidal effect ( > 3 log10 reduction of viable cells) within a short time (10 to 120 min) . Similar formulations produced by different manufacturers exhibited comparable activity against P . aeruginosa.

Graefes Arch Clin Exp Ophthalmol, 1995 Aug, 233(8), 532 - 4
Efficacy of topical gentamicin treatment after 193-nm photorefractive keratectomy in an experimental Pseudomonas keratitis model; Frucht-Pery J et al.; BACKGROUND: The treatment of Pseudomonas keratitis has many limitations, and further investigation to identify more effective approaches is required . We therefore studied the possible contribution of the debridement effect of 193-nm excimer laser on Pseudomonas keratitis in rabbit eyes . METHODS: Pseudomonas keratitis was induced in 30 rabbit eyes by inflicting controlled central corneal scratches and applying a drop of Pseudomonas aeruginosa suspension . After 24 h, one cornea of each animal was photo-ablated (excimer laser: fluency 90 mJ/cm2, 10 Hz, 213 pulses), yielding 50 microns of tissue ablation, while the follow cornea served as control . Five groups of six animals each were formed and received: a subconjunctival injection of gentamicin 20 mg (group 1), topical 14 mg/ml gentamicin hourly (group 2) or every 2.5 h (group 3), or NaCl 0.9% hourly (group 4) for 8 h . In group 5, animals were sacrificed without additional treatment . After 9 h corneas were excised, homogenized, serially diluted, and plated on agar blood plates . The numbers of colony-forming units (CFU) per cornea were statistically evaluated (Mann-Whitney test) . RESULTS: In control eyes, a greater decrease of CFU was observed in group 2 than in group 3 (P = 0.03) . In laser-ablated eyes, there was no difference in CFU between groups 2 and 3 . Comparison of the excimer-treated and control eyes revealed a greater number of bacteria (CFU) in controls only in group 3 (P = 0.02) . CONCLUSION: Our study suggests that controlled debridement of cornea with excimer laser may improve the effect of topical antibiotics.

Hybridoma, 1995 Aug, 14(4), 323 - 8
Production of ScFv antibody fragments following immunization with a phage-displayed fusion protein and analysis of reactivity to surface-exposed epitopes of the protein F of Pseudomonas aeruginosa by cytofluorometry; Kermani P et al.; To increase the possibilities of obtaining antibodies to surface-exposed epitopes of Pseudomonas aeruginosa protein F, we immunized mice with cloned and expressed oprF gene as a gIII-fusion protein displayed on the M13 phage surface . The fusion protein elicited mouse antibodies reacting with the purified protein F at a limit dilution of 1:10,000 . Recombinant clones expressing antibody fragments were constructed from the genes of selected B cells of hyperimmunized mouse after a first round of panning against the protein F . Expression of single chain Fv (ScFv) antibody fragments to the protein of P . aeruginosa was detected by ELISA in 20 of 384 clones obtained after the first panning selection . The 20 positive clones recognizing different protein F epitopes as demonstrated by ELISA were assayed by flow cytometry to identify antibody fragments reacting only with surface-exposed epitopes of the protein F on whole bacteria; one of the 20 clones tested showed a level of reactivity compatible with surface-exposed epitope that can lead to ulterior developments in targeting studies.

J Vet Med Sci, 1995 Aug, 57(4), 599 - 602
Enhancement of resistance to bacterial infection in mice by vitamin B2; Araki S et al.; We found that the intramuscular injection of vitamin B2 enhanced host resistance to E . coli infection in a dose-dependent manner (6.25 mg/kg-100 mg/kg) . Furthermore, VB2 exhibited the protective activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Actinobacillus pleuropneumoniae . The mechanism of action of VB2 for enhancing resistance in mice may be, at least in part, its ability to stimulate the multiplication of neutrophils and monocytes, and to activate macrophages.

J Clin Epidemiol, 1995 Aug, 48(8), 1041 - 9
Gender differences in cystic fibrosis: Pseudomonas aeruginosa infection; Demko CA et al.; The median survival age for females with cystic fibrosis (CF) is approximately 3 years younger than for males . We tested whether earlier acquisition of Pseudomonas aeruginosa (PA) by female CF patients or the greater impact of this organism on their lung disease, or both, contribute to their poorer survival . PA infection status, survival, pulmonary function tests, and chest X-ray scores from patients who were followed at our center for at least 2 years with a minimum of three respiratory cultures per year were analyzed (n = 848) . The median age of chronic infection with mucoid PA was 1.7 years earlier in females than in males . Patients infected with mucoid PA had poorer survival, chest X-ray scores, and pulmonary function tests than patients who had either no Pseudomonas species or only the nonmucoid phenotype . Acquisition of mucoid PA was associated with an accelerated rate of decline in pulmonary function . However, the rate of change of pulmonary function after mucoid PA infection was similar for males and females . Moreover, even among patients who had only the mucoid form or only the nonmucoid form, males had better percent predicted forced expiratory volume in 1 sec and better survival . Therefore, factors in addition to earlier acquisition of mucoid PA may contribute to the poorer survival of female CF patients.

J Bacteriol, 1995 Aug, 177(16), 4801 - 4
Identification of Pseudomonas aeruginosa glpM, whose gene product is required for efficient alginate biosynthesis from various carbon sources; Schweizer HP et al.; In a mucB (algN) genetic background, insertion of an omega element approximately 200 bp downstream of glpD, encoding sn-glycerol-3-phosphate dehydrogenase from Pseudomonas aeruginosa, had an adverse effect on alginate biosynthesis from various carbon sources . The insertion inactivated glpM, a gene encoding a 12,040-M(r) hydrophobic protein containing 109 amino acids . This protein, which was expressed in a T7 RNA polymerase expression system, appears to be a cytoplasmic membrane protein.

Surg Clin North Am, 1995 Aug, 75(4), 799 - 809
Infections in lower extremity vascular grafts; Piano G; No set of rigid guidelines can replace a clinically rational and methodic approach to the patient with an infrainguinal graft infection . Some fundamental principles are common to infrainguinal graft infections that form the basis for selective management: 1 . Graft preservation can be attempted when the graft is patent, the anastomosis is intact, and the patient is not septic . 2 . Graft excision is mandatory when the patient presents with a thrombosed infected graft, anastomotic or graft hemorrhage, or significant systemic sepsis . 3 . Graft preservation can be attempted in both vein and PTFE grafts but is not advised for Dacron grafts . This approach should be tempered by the extent and virulence of the underlying infection, especially when Pseudomonas aeruginosa is the pathologic organism . 4 . Delayed hemorrhage and continued systemic sepsis represent early failures of graft preservation and mandate graft excision . 5 . Revascularization may be accomplished through the infected bed, but it is generally prudent to proceed with extra-anatomic reconstruction utilizing alternative approaches to inflow and outflow vessels.

J Pediatr, 1995 Aug, 127(2), 263 - 8
Value of routine anaerobic blood cultures for pediatric patients; Zaidi AK et al.; OBJECTIVE: Anaerobic bacteremia rarely occurs in children . Therefore we assessed the usefulness of routinely obtaining anaerobic blood cultures in our pediatric patients . STUDY DESIGN: Records of 9360 paired aerobic anaerobic blood culture bottles (Bactec NR660 System) containing blood specimens from pediatric inpatients and outpatients at Duke University Medical Center, Durham, N.C., were reviewed retrospectively . Yield and speed of detection were calculated for each bottle and compared for statistical significance by the McNemar test . RESULTS: A total of 723 clinically important microorganisms were isolated; only 15 (2.1%) were strict anaerobes . Significantly more microorganisms (p < 0.001), especially staphylococci, nonfermenting gram-negative rods, enteric gram-negative rods, and yeasts, were detected by use of the aerobic bottle . The anaerobic bottle was important in identifying an anaerobic microorganism as the cause of sepsis in only five patients, all of whom were at increased risk of having anaerobic infection . CONCLUSIONS: Anaerobic blood cultures are rarely helpful in the majority of pediatric patients and usually show positive results only in clinical settings associated with anaerobic infection . Microorganisms that prefer an aerobic environment, such as Pseudomonas aeruginosa and yeasts, are now far more common than anaerobes in children; aerobic culturing of the entire volume of blood collected might increase the yield from pediatric blood cultures.

J Bacteriol, 1995 Aug, 177(15), 4377 - 84
Host growth temperature and a conservative amino acid substitution in the replication protein of pPS10 influence plasmid host range; Fernandez-Tresguerres ME et al.; pPS10 is a replicon isolated from Pseudomonas syringe pv . savastanoi that can be established at 37 degrees C efficiently in Pseudomonas aeruginosa but very inefficiently in Escherichia coli . The establishment of the wild-type pPS10 replicon in E . coli is favored at low temperatures (30 degrees C or below) . RepA protein of pPS10 promotes in vitro plasmid replication in extracts from E . coli, and this replication depends on host proteins DnaA, DnaB, DnaG, and SSB . Mutant plasmids able to efficiently replicate in E . coli at 37 degrees C were obtained . Three of four mutants whose mutations were mapped show a conservative Ala-->Val change in the amino-terminal region of the replication protein RepA . Plasmids carrying this mutation maintain the capacity to replicate in P . aeruginosa and have a fourfold increase in copy number in this host . The mutation does not substantially alter the autoregulation mediated by RepA . These results show that the physiological conditions of the host as well as subtle changes in the plasmid replication protein can modulate the host range of the pPS10 replicon.

Am J Respir Crit Care Med, 1995 Aug, 152(2), 765 - 74
Imbalance between 95 kDa type IV collagenase and tissue inhibitor of metalloproteinases in sputum of patients with cystic fibrosis; Delacourt C et al.; A growing body of evidence suggests that neutrophil-derived proteinases play a major role in lung tissue damage in cystic fibrosis (CF) . Most previous studies have focused on serine proteinases such as neutrophil elastase, providing no information on the extent to which metalloproteinases participate in proteolytic processes in CF . To address this issue, we evaluated the contribution of one of the major neutrophil metalloproteinases, i.e., 95 kDa gelatinase (type IV collagenase), to the total gelatinolytic activity measured in sputum specimens from 27 patients with CF . Compared with asthmatic children (n = 9), CF patients had a 6.7 times greater level of total gelatinase activity in sputum revealed by zymography . The 95 kDa gelatinase was increased 3.7-fold in the CF subjects (2,441 +/- 411 {SEM} arbitrary units {AU} x 10(6) per ml of sputum versus 665 +/- 201 in asthmatics) and the 88-kDa active form 23.2-fold (2,272 +/- 372 AU x 10(6) per ml of sputum versus 98 +/- 43, respectively) . Using radiolabeled 3H-gelatin as the substrate, we demonstrated uninhibited gelatinolytic activity in all CF patients; this activity was significantly correlated to disease severity as assessed by pulmonary function tests . Western blotting using anti-tissue inhibitor of metalloproteinase (anti-TIMP) and anti-95/88-kDa gelatinase antibodies demonstrated a more than 10-fold excess of 95/88 kDa gelatinase over TIMP . Bacterial proteinases from Pseudomonas aeruginosa were shown to contribute little to the gelatinolytic activity measured in sputum supernatants from patients with CF, although culture supernatants from various P . aeruginosa strains expressed gelatinolytic activity in vitro . Finally, lung damage, as assessed by increased type IV collagen degradation products in sputum, was significantly correlated to concentrations of active 88 kDa gelatinase . These data argue for a significant role of 95/88 kDa gelatinase in airway damage in CF.

J Med Microbiol, 1995 Aug, 43(2), 141 - 7
A protective role for lymphocytes in cyclophosphamide-induced endogenous bacteraemia in mice; Hirakata Y et al.; Cyclophosphamide (CY) is used in many animal studies, including models of bacteraemia, to deplete peripheral neutrophils and induce a compromised state . Although CY also influences lymphocyte function, the protective role of lymphocytes in bacteraemia is unclear . Therefore, CY (200 mg/kg) was administered to ddY mice and its influence on the number, cellular composition, and function of lymphocytes in the spleen and Peyer's patches was examined . A single dose of CY reduced the number of lymphocytes in a time-dependent fashion . Flow cytometry showed that B cells carrying B220 antigen decreased significantly . The production of IgA in Peyer's patches, as measured by enzyme-linked immunosorbent assay, was also suppressed in a time-dependent fashion . Blastogenic responses of splenic lymphocytes to Concanavalin-A, lipopolysaccharide and heat-killed Pseudomonas aeruginosa were suppressed 48 h after CY administration . The results suggest that CY suppresses the number and function of lymphocytes, especially B cells . This may lead to bacterial overgrowth in the gut and result in bacteraemia . Intravenous transfusion of normal lymphocytes or oral inoculation of IgA to mice with P . aeruginosa D4 endogenous bacteraemia significantly increased survival rates, indicating that lymphocytes and their products have a protective role in bacteraemia in mice.

J Infect Dis, 1995 Aug, 172(2), 453 - 61
Cross-sectional and longitudinal studies of naturally occurring antibodies to Pseudomonas aeruginosa in cystic fibrosis indicate absence of antibody-mediated protection and decline in opsonic quality after infection; Tosi MF et al.; Most patients with cystic fibrosis (CF) develop chronic endobronchial infection with mucoid Pseudomonas aeruginosa . It has been suggested that opsonic antibodies to the mucoid exopolysaccharide of P . aeruginosa protect older CF patients (> 12 years of age) who have remained free of colonization by this organism . Serum antibodies from chronically infected CF patients had greater total complement-dependent opsonic activity than did those of older noncolonized patients (P < .02), but when bound antibody was equalized, opsonic quality was greater for the latter group (P < .03) . In longitudinal studies, antibody titers to mucoid P . aeruginosa rose greatly after initial infection, but opsonic quality declined (P = .002) . Twenty CF patients who passed age 12 free of P . aeruginosa colonization developed chronic P . aeruginosa lung infection at ages 14-35 years . Thus, naturally occurring antibodies do not protect CF patients from P . aeruginosa infection, and opsonic quality of serum antibodies deteriorates as infection becomes established.

Infect Immun, 1995 Aug, 63(8), 3182 - 6
Functional domains of Pseudomonas aeruginosa exoenzyme S; Knight DA et al.; Recombinant exoenzyme S (rHisExoS) of Pseudomonas aeruginosa was expressed in Escherichia coli as a soluble, cytosolic His fusion protein . rHisExoS was purified by Ni(2+)-affinity chromatography in the presence of protease inhibitors without detectable degradation . rHisExoS possessed a specific activity (within twofold) for the factor-activating exoenzyme S-dependent ADP-ribosylation of soybean trypsin inhibitor (SBTI) similar to that of native exoenzyme S . Analysis of several deletion peptides showed that delta N222, which encoded the carboxyl-terminal 222 amino acids of exoenzyme S, possessed factor-activating exoenzyme S-dependent ADP-ribosyltransferase activity . delta N222 catalyzed the ADP-ribosylation of SBTI at a rate sixfold greater than rHisExoS . Relative to rHisExoS, delta N222 had a similar affinity for NAD, a threefold greater affinity for SBTI, and a four- to eightfold greater kcat for the ADP-ribosylation of SBTI . Like native exoenzyme S, rHisExoS chromatographed as an aggregate with an apparent molecular mass of > 300 kDa . In contrast, delta N222 did not chromatograph as an aggregate, which showed that the amino-terminal 99 amino acids of exoenzyme S were responsible for the aggregation phenotype.

Arch Otolaryngol Head Neck Surg, 1995 Aug, 121(8), 880 - 4
Topical ciprofloxacin for otorrhea after tympanostomy tube placement; Force RW et al.; OBJECTIVE: To evaluate the efficacy, systemic absorption, and safety of ototopically administered ciprofloxacin in children with otorrhea associated with tympanostomy tube placement . DESIGN: Nonrandomized, open-label pilot trial with pharmacokinetic determination of the systemic absorption of ototopical ciprofloxacin . SETTING: A pediatric otolaryngology clinic affiliated with Columbus (Ohio) Children's Hospital . PATIENTS: Patients aged 3 to 8 years were enrolled if they had persistent otorrhea associated with tympanostomy tube placement . Other inclusion criteria were culture of Pseudomonas aeruginosa from the drainage material; failure of previous oral antibiotic therapy; and ability to participate in bone conduction audiometry . INTERVENTION: Participants received 3 drops (approximately 60 microL) of 0.3% ototopical ciprofloxacin hydrochloride (Ciloxan, Alcon Laboratories Inc, Forth Worth, Tex), three times a day, for 14 days . Bone conduction audiometry was performed at baseline and on day 14 . Patients were examined on days 7 and 14 for efficacy of treatment (improvement, cure, failure) and adverse effects . On day 7, blood samples were drawn just before and 1 hour after the dose was given . Concentrations of ciprofloxacin were measured by high-performance liquid chromatography, with a 5 ng/mL limit of detection . Telephone follow-up was performed on day 44 . Parents were asked about adverse effects at days 7, 14, and 44 . RESULTS: Mean duration of ear drainage at baseline was 10.7 months (0.75 to 36 months) . Ten of 11 infected ears (nine of 10 patients) were improved or cured at day 7 . Ten of 11 ears were completely cured at days 14 and 44 . No adverse effects were noted or reported by the children's parents . One child had abnormal bone conduction audiometry results at baseline . The results of bone conduction audiometry on day 14 were normal in all children . Trough concentrations of ciprofloxacin were determined in eight of 10 children; and peak concentrations were determined in seven of 10 children . Ciprofloxacin was not detected in the plasma of any child . CONCLUSION: Topical ciprofloxacin was found to be safe and effective in treating otorrhea in children who did not respond to other treatments.

Radiology, 1995 Aug, 196(2), 409 - 14
Invasive pulmonary aspergillosis in AIDS: radiographic, CT, and pathologic findings; Staples CA et al.; PURPOSE: To review the radiographic and computed tomographic (CT) manifestations of invasive pulmonary aspergillosis and to correlate the imaging and pathologic findings in patients with acquired immunodeficiency syndrome (AIDS) . MATERIALS AND METHODS: Chest radiographs, CT scans, and pathologic specimens were reviewed retrospectively in 10 AIDS patients with proved invasive pulmonary aspergillosis . RESULTS: The most common radiographic finding was the presence of thick-walled cavitary lesions . Less common findings included nodules, consolidation, and pleural effusion . CT depicted more nodules and cavities than did radiography . The predominant pathologic abnormalities consisted of tissue invasion and abscess formation and angioinvasion with or without infarction . All patients had infection with Aspergillus fumigatus as well as other pathogens, the most common being cytomegalovirus and Pseudomonas aeruginosa . CONCLUSION: Thick-walled cavitary lesions are the most common radiologic manifestation of invasive pulmonary aspergillosis in AIDS . The findings are more numerous and better defined on CT scans . The radiologic findings reflect a spectrum of pathologic abnormalities.

Curr Microbiol, 1995 Aug, 31(2), 124 - 8
Reactive oxygen species in the killing of Pseudomonas aeruginosa by human leukocytes; Mizgerd JP et al.; Pseudomonas aeruginosa (PA) infects hosts with compromised host defenses . An important defense mechanism is the generation of reactive oxygen species (ROS) by white blood cells (WBCs) . What roles do ROS play in host defense against PA? Human WBCs killed PA in vitro, and they generated a respiratory burst as measured by the production of H2O2 . ROS efficiently killed PA; in acellular assays, less than 10 mM of H2O2 or OCl- eliminated all bacteria in 90 min . However, WBCs with suppressed production of ROS (caused by hypoxia) killed PA normally . In addition, none of the antioxidants vitamin C, N-acetylcysteine, superoxide dismutase, or catalase affected PA killing by WBCs . Thus, PA stimulates WBCs to produce ROS, which can kill the bacteria, but disturbances of WBC ROS production do not interfere with the killing of PA . WBCs have robust, redundant mechanisms for PA elimination.

Genetika, 1995 Aug, 31(8), 1065 - 72
{Origin and properties of Pseudomonas aeruginosa PAO1 clones surviving after induction of prophages-transposons}; Krylov VN et al.; Various mutations cancelling the lethal effect of phage lytic development and simultaneous phenotypic modifications were found in rare clones surviving after incubation at 42 degrees C of Pseudomonas aeruginosa (D3112 cts 15), lysogenic for thermoinducible mutant cts 15 of the transposable prophage (TP) D3112 . All mutations arose prior to thermal induction . Temperature induction of other bacteriophages (nontransposable) did not lead to selection of bacterial morphological mutants . Therefore, it was concluded that mutagenesis occurred upon the partial (reversible) TP derepression accompanied by coupled replication-transposition of TP, the latter being the direct cause of the mutator effect . Isolation of the P . aeruginosa PAO1 mutant R10 (this mutant is resistant to infection with TP at 42 degrees C) allowed the proper selection and examination of numerous survivors . Comparison of their types derived from lysogens with different prophage location indicated that the number of secondary sites where TP integration is possible without the loss of cell viability is limited . Several transposition events occurred in the history of some survivors (during a repeated or single derepression event) . Type D clones, which produce small colonies, are of special interest, because mechanisms underlying the survival of such clones are extremely diverse, and their phenotypes indicate the possibility of stable chromosomal rearrangements in the genome of P . aeruginosa.

J Ind Microbiol, 1995 Aug, 15(2), 103 - 7
An impedimetric method for rapid screening of cosmetic preservatives; Zhou X et al.; An efficient impedance method was developed for rapid evaluation of cosmetic preservatives . The method used decimal reduction time or D-value to assess preservative efficacies . The D-value, which was calculated from the plot of Log CFU ml-1 versus time by linear regression analysis, could be obtained within 48 h . Thus, the time required for the challenge test was reduced from 4-8 weeks with the standard procedures (eg US Pharmacopeia), to 2 days with the current method . A calibration curve (r = -0.95) was established by plotting the Log CFU ml-1 versus capacitance detection time (DT) of 108 samples . With the calibration, CFU can be estimated directly from the impedance test without plating . Two commercial biocides and several other chemicals were evaluated in a shampoo by the impedance procedure against Pseudomonas aeruginosa . The D-values obtained from the impedance test were not significantly different from those produced by the conventional plate count method . The technique was found to be particularly useful when screening a large number of compounds to find novel preservatives and synergistic preservative combinations.

Rinsho Ketsueki, 1995 Aug, 36(8), 786 - 91
{Aplastic anemia with giant splenomegaly and myelofibrosis successfully treated with antilymphocyte globulin}; Kaito K et al.; Severe aplastic anemia was diagnosed in a 58-year-old female because of pancytopenia with leukocyte count 700/microliters, hemoglobin 3.4 g/dl, platelet count 4.2 x 10(4)/microliters and fatty hypoplastic bone marrow in August 1992 . In January 1993, she was admitted with an abdominal skin infection caused by pseudomonas aeruginosa . After treatment of the infection, antilymphocyte globulin was given at a dose of 2,000 mg/day for four consecutive days in July 1993 . This resulted in a gradual but steady improvement in her hematological data . In February 1995, her leukocyte count increased to 2,000/microliters, hemoglobin to 15.2 g/dl and platelet count to 11.0 x 10(4)/microliters . Although no splenomegaly or myelofibrosis was found previously, from April 1993, the spleen enlarged and was palpable 10 cm below the costal margin . Her bone marrow biopsy in June 1993 revealed prominent myelofibrosis . Thereafter no changes were found in these features . Splenomegaly and myelofibrosis are characteristic of primary myelofibrosis and although the relationship is uncertain, there is no previous report on aplastic anemia with splenomegaly and myelofibrosis.

J Clin Microbiol, 1995 Aug, 33(8), 2216 - 9
Comparison of arbitrarily primed PCR and macrorestriction (pulsed-field gel electrophoresis) typing of Pseudomonas aeruginosa strains from cystic fibrosis patients; Kersulyte D et al.; Arbitrarily primed PCR fingerprinting was carried out on 43 Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients . Seventeen major groups of strains that coincided with groups also distinguished by macrorestriction (pulsed-field gel electrophoresis) typing were identified . Our results illustrated that a CF patient can carry more than one strain and can carry a given strain for long periods of time and that strains can evolve by changes in drug resistance or other phenotypic traits during long-term colonization . The arbitrarily primed PCR method is recommended for first-pass screening of P . aeruginosa isolates from CF patients, especially when many strains are to be typed, because of its sensitivity and efficiency.

J Hosp Infect, 1995 Aug, 30(4), 295 - 303
Evaluation of three glutaraldehyde-based disinfectants used in endoscopy; Jette LP et al.; The European suspension test was applied to compare the in vitro activity of three glutaraldehyde-based disinfectants: a 1:10 dilution of a 10% glutaraldehyde solution containing 0.5% phenylphenol-0.1% amylphenol, a 2% acid glutaraldehyde solution, and a 2% alkaline glutaraldehyde solution . The microbicidal effect of the disinfectants was evaluated by counting surviving cells of three indicator microorganisms (Pseudomonas aeruginosa, Mycobacterium chelonae and phage f2) after exposure times of 5, 10, 20 and 40 min to the agents at 20 degrees C . An inactivation factor (IF) of > or = 5 log10 was used as the criterion for effective disinfection . This IF was achieved with every microorganism/disinfectant combination after 5 min exposure except in experiments with phage f2 and the 1% glutaraldehyde-based disinfectant . The diminished inactivation noticed with the 1% glutaraldehyde-based disinfectant supports the recommendation to use a disinfectant containing a minimum of 2% glutaraldehyde for high level disinfection.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1881 - 4
OXA-14, another extended-spectrum variant of OXA-10 (PSE-2) beta-lactamase from Pseudomonas aeruginosa; Danel F et al.; Pseudomonas aeruginosa 455, isolated in Ankara, Turkey, produced a pI 6.2 beta-lactamase determined by plasmid pMLH53 and resisted all beta-lactams except carbapenems . This beta-lactamase, named OXA-14, corresponded to OXA-10 (PSE-2) except that aspartate replaced glycine at position 157 and thus is intermediate between OXA-10 and OXA-11, which has aspartate at position 157 and a further substitution at position 143.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1871 - 4
Cloning and characterization of the Pseudomonas aeruginosa pbpB gene encoding penicillin-binding protein 3; Liao X et al.; Clones containing the pbpB gene which encodes penicillin-binding protein (PBP) 3 of Pseudomonas aeruginosa were detected by hybridization by PCR amplification with primers based on the conserved sequences of high-molecular-weight PBPs . The translated amino acid sequence demonstrated 45% identity and had a total of 66% conserved amino acids relative to the Escherichia coli PBP3 . The pbpB gene was located upstream of a gene homologous to the E . coli murE gene, which encodes uridine diphosphate-N-acetyl muramic acid-tripeptide synthetase . The overexpressed pbpB gene product reacted with 3H-penicillin G and had an apparent molecular weight of 60,000.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1797 - 801
Pharmacodynamics of ceftazidime administered as continuous infusion or intermittent bolus alone and in combination with single daily-dose amikacin against Pseudomonas aeruginosa in an in vitro infection model; Cappelletty DM et al.; We compared the pharmacodynamics and killing activity of ceftazidime, administered by continuous infusion and intermittent bolus, against Pseudomonas aeruginosa ATCC 27853 and ceftazidime-resistant P . aeruginosa 27853CR with and without a single daily dose of amikacin in an in vitro infection model over a 48-h period . Resistance to ceftazidime was selected for by serial passage of P . aeruginosa onto agar containing increasing concentrations of ceftazidime . Human pharmacokinetics and dosages were simulated as follows: half-life, 2 h; intermittent-bolus ceftazidime, 2 g every 8 h (q8h) and q12h; continuous infusion, 2-g loading dose and maintenance infusions of 5, 10, and 20 micrograms/ml; amikacin, 15 mg/kg q24h . There was no significant difference in time to 99.9% killing between any of the monotherapy regimens or between any combination regimen against ceftazidime-susceptible P . aeruginosa . Continuous infusions of 10 and 20 micrograms/ml killed as effectively as an intermittent bolus of 2 g q12h and q8h, respectively . Continuous infusion of 20 micrograms/ml and an intermittent bolus of 2 g q8h were the only regimens which prevented organism regrowth at 48 h, while a continuous infusion of 5 micrograms/ml resulted in the most regrowth . All of the combination regimens exhibited a synergistic response, with rapid killing of ceftazidime-susceptible P . aeruginosa and no regrowth . Against ceftazidime-resistant P . aeruginosa, none of the ceftazidime monotherapy regimens achieved 99.9% killing . The combination regimens exhibited the same rapid killing of the resistant strain as occurred with the susceptible strain; however, regrowth occurred with all regimens . The combination regimens of continuous infusion of 20 micrograms/ml plus amikacin and intermittent bolus q8h or q12h plus amikacin continued to be synergistic . Overall, continuous infusion monotherapy with ceftazidime at concentrations 4 to 5 and 10 to 15 times the MIC was as effective as an intermittent bolus of 2 g q12h (10 to 15 times the MIC) and q8h (25 to 35 times the MIC), respectively, against ceftazidime-susceptible P . aeruginosa . Combination therapy with amikacin plus ceftazidime, either intermittently q8h or by continuous infusion of 20 micrograms/ml, appeared to be effective and exhibited synergism against ceftazidime-resistant P . aeruginosa.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1744 - 7
Interleukin-1 (IL-1)-induced resistance to bacterial infection: role of the type I IL-1 receptor; Vogels MT et al.; Pretreatment with a low dose of recombinant human interleukin-1 beta (IL-1) (3 to 30 micrograms/kg) 24 h before a lethal Pseudomonas aeruginosa infection prolongs survival in neutropenic mice . We investigated the role of the type I IL-1 receptor (IL-1RI) and IL-1RII in this IL-1-induced protection by using a specific IL-1 receptor antagonist (IL-1-Ra), which blocks effects mainly via IL-1RI . Pretreatment with IL-1Ra before IL-1 partially blocked the IL-1-induced enhanced survival, whereas pretreatment with a specific neutralizing monoclonal antibody to IL-1RI (35F5) eliminated the IL-1 induced protection . The nonapeptide fragment 163-171 of recombinant human IL-1 beta, which possesses the immunoadjuvant but not the inflammatory effect of the entire molecule via a non-receptor-mediated signal transduction process, did not reproduce the IL-1-induced protection . IL-1-induced protection was associated with reduced serum aspartate aminotransferase and alanine aminotransferase concentrations in conjunction with ameliorated histopathology of the liver . These findings may be due to reduced cytokine production and cytokine sensitivity of target cells after infection . We conclude that the IL-1-induced nonspecific resistance to infection is mediated by cells bearing IL-1RI and is associated with a reduction of liver damage.

Antimicrob Agents Chemother, 1995 Aug, 39(8), 1731 - 5
Purification of a 54-kilodalton protein (OprJ) produced in NfxB mutants of Pseudomonas aeruginosa and production of a monoclonal antibody specific to OprJ; Hosaka M et al.; The 54-kDa outer membrane protein (designated OprJ) of a norfloxacin-resistant nfxB mutant of Pseudomonas aeruginosa PAO1 was purified by ion-exchange high-performance liquid chromatography . Mobility of OprJ in sodium dodecyl sulfate-polyacrylamide gel electrophoresis was not affected by reduction and heating . A murine monoclonal antibody (MAb) against OprJ was prepared to investigate existence of this protein in fluoroquinolone-susceptible and -resistant strains of P . aeruginosa . Western blot (immunoblot) analysis with this MAb revealed a single band at the position corresponding to OprJ in outer membrane proteins of NfxB mutants derived from clinical isolates . However, the MAb did not react with any outer membrane proteins of the respective parent strains . Complementation of the NfxB mutation by transformation with plasmid pNF111, which contained the wild-type nfxB gene, led to disappearance of the single band corresponding to OprJ . The existence of OprJ was associated with fluoroquinolone resistance . Furthermore, the MAb did not react with any outer membrane proteins of other fluoroquinolone-resistant nalB and nfxC mutants . These results suggest that OprJ is newly produced in NfxB mutants of P . aeruginosa and is involved in fluoroquinolone resistance specific to NfxB, and it appears that the MAb to OprJ should aid in detection of the NfxB mutation in P . aeruginosa.

Arch Intern Med, 1995 Jul 24, 155(14), 1547 - 50
Intracellular bacteria in blood smears in patients with central venous catheters; Torlakovic E et al.; The presence of intracellular bacteria in blood smears is usually associated with overwhelming sepsis and an ominous prognosis . Recently, the hematology laboratory at our institution documented this finding in a group of mostly asymptomatic patients . We studied seven adult patients from a tertiary care university hospital in whom intracellular bacteria were found incidentally on routine manual differential cell counts of 100 white blood cells during a 12-month period . A retrospective review of the clinical and laboratory data was performed . All seven patients were immunosuppressed and had central venous catheters in place . The blood samples positive for intracellular bacteria were all catheter derived . Six patients were asymptomatic at the time of bacteria detection, but they had blood cultures that were positive for coagulase-negative Staphylococcus; five of these patients became symptomatic 1 to 14 days after bacteria detection . Bacteremia persisted in five of these six patients until the eventual removal of the catheters . The one symptomatic patient had Pseudomonas aeruginosa bacteremia and died shortly after admission . The finding of intracellular bacteria in routine differential blood cell counts from a central venous catheter blood specimen most likely indicates active infection . We recommend that central venous catheters be removed in such patients, even if the patient is asymptomatic.

Mol Gen Genet, 1995 Jul 22, 248(1), 17 - 24
A positive regulatory gene, pvdS, for expression of pyoverdin biosynthetic genes in Pseudomonas aeruginosa PAO; Miyazaki H et al.; In response to iron limitation Pseudomonas aeruginosa PAO induces production of pyoverdin, a low-molecular-weight siderophore able to capture ferric ion with a very high affinity . The pvd genes involved in the pyoverdin biosynthesis are organized in a chromosomal region termed the pvd region, and expression of some pvd genes is regulated at the transcriptional level . Two sets of promoter regions for the pvd genes were defined that were transcriptionally derepressed under iron-limiting conditions . Analysis of transcription from such promoters in Escherichia coli led to isolation and identification of a positive regulatory gene, pvdS, for expression of the pvd genes, and pvdS was localized in the pvd region . A genomic pvdS mutant of PAO, constructed by allelic exchange mutagenesis, produced no pyoverdin and did not allow transcription from the pvd promoters . Nucleotide sequence analysis revealed that PvdS shows considerable similarity to FecI of E . coli, a positive regulator for transcription of the fec (ferric citrate transport system) operon . The promoter region of pvdS has the sequence that matches well the consensus binding site for the E . coli Fur protein, a global negative regulatory protein that represses the transcription of the iron-repressible genes . Consistent with the presence of such a consensus sequence, addition of iron repressed transcription of the pvdS gene in P . aeruginosa.

Eur J Biochem, 1995 Jul 15, 231(2), 358 - 69
1H-NMR study of a cobalt-substituted blue copper protein: Pseudomonas aeruginosa Co(II)-azurin; Salgado J et al.; Substitution of copper by cobalt in blue copper proteins gives a paramagnetic metalloderivative suitable for paramagnetic NMR studies . A thorough analysis of the 1H-NMR spectrum of Pseudomonas aeruginosa Co(II)-azurin is presented here . All the observable contact-shifted signals as well as many other paramagnetic signals from protons placed up to about 1.0 nm around the metal center, including some residues belonging to functionally important parts of the protein like the hydrophobic patch and the His35 region, have been assigned . The results obtained permit the detection and study of structural variations like those originated by the His35 ionization, and allow us to draw a feasible picture of the metal coordination site . Contact-shifted signals correspond to the same five residues which are found in the coordination sphere of the native Cu(II)-azurin, i.e . His46, His117, Cys112, Met121 and Gly45 . Among them, the histidine residues present a pattern of resonances typical for histidines coordinated to cobalt in other cobalt protein derivatives, and the cysteine signals clearly indicate a strong interaction with the paramagnetic Co(II) ion . In contrast, the Met121 signals indicate a weak but still existent contact interaction with the metal center . On the other hand, the very weak copper ligand, Gly45, appears here as clearly coordinated to cobalt . Results are consistent with a distorted tetrahedral metal site with the cobalt deviated from the N2S plane towards the Gly45 O axial position and weakly interacting with the Met121 sulfur.

Biochem J, 1995 Jul 15, 309 ( Pt 2), 507 - 11
Purification and characterization of citrate synthase isoenzymes from Pseudomonas aeruginosa; Mitchell CG et al.; Two types of citrate synthase (CS) have been purified from Pseudomonas aeruginosa, a 'large' form (CSI) and a 'small' form (CSII) . The M(r)s of the CSI and CSII isoenzymes were determined to be 240,000 +/- 16,000 (mean +/- S.E.M.) and 80,300 +/- 3800 respectively . Chemical cross-linking of the native enzymes with either dimethyl suberimidate or glutaraldehyde followed by electrophoretic analysis by SDS/PAGE showed that CSI is a hexamer and CSII is a dimer . SDS/PAGE showed that CSI and CSII each consist of a single subunit type, of M(r) 42,000 +/- 2000 and M(r) 36,500 +/- 2000 respectively . CSI and CSII were also shown to be distinct kinetically, immunologically and in terms of their regulatory properties . It is suggested that the CS isoenzymes are products of different structural genes.

N Engl J Med, 1995 Jul 13, 333(2), 95 - 9
A cystic fibrosis mutation associated with mild lung disease; Gan KH et al.; BACKGROUND . Cystic fibrosis is the most common lethal autosomal recessive disorder among whites . Among Dutch patients with cystic fibrosis, delta F508 is the most common mutation and A455E the second most common mutation of the cystic fibrosis transmembrane conductance regulator gene on chromosome 7 . A455E is associated with preserved pancreatic function and residual secretion of chloride across membranes . We investigated whether it is also associated with less severe pulmonary disease in patients with cystic fibrosis . METHODS . A total of 33 patients with compound heterozygosity for the A455E mutation were matched according to age and sex with patients who were homozygous for the delta F508 mutation . The pairs were analyzed with respect to the following outcome variables: age at diagnosis, pulmonary-function values, and the frequency of pseudomonas colonization, pancreatic sufficiency, and diabetes mellitus . RESULTS . Cystic fibrosis was diagnosed at a later age in the patients with the A455E mutation than in the delta F508 homozygotes (mean age at diagnosis, 15.0 vs . 3.1 years; P < 0.001) . Fewer patients with the A455E mutation had pancreatic insufficiency (21.2 percent vs . 93.9 percent, P < 0.001), and none had diabetes mellitus (0 percent vs . 27.3 percent, P = 0.004) . Forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were significantly higher in the patients with the A455E mutation (mean FEV1, 73.9 percent of the predicted value vs . 54.3 percent of the predicted value; P = 0.002; mean FVC, 88.7 percent of the predicted value vs . 76.3 percent of the predicted value; P = 0.04) . Fewer patients with the A455E mutation were colonized with Pseudomonas aeruginosa (33.3 percent vs . 60.6 percent, P = 0.02) . CONCLUSIONS . A455E is a common mutation causing cystic fibrosis in the Netherlands . Although several mutations are known to be associated with less severe pancreatic disease, our findings demonstrate a correlation between the A455E mutation and mild pulmonary disease . Because mortality in this disease depends primarily on the progression of pulmonary disease, patients with the A455E mutation have a better prognosis than patients who are homozygous for the delta F508 mutation.

Rev Latinoam Microbiol, 1995 Jul-Sep, 37(3), 209 - 16
Osmoregulation in Pseudomonas aeruginosa under hyperosmotic shock; Velasco R et al.; Pseudomonas aeruginosa PAO1 strain was found to be able to tolerate 700 mM NaCl . 0.5 mM of the osmoprotectant betaine restablished the growth of this strain in 1200 mM NaCl . Intracellular K+ and glutamate concentrations of P . aeruginosa PAO1 after an hyperosmotic shock (400 mM NaCl) showed a permanent increase . Adition of betaine (0.5 mM) to the medium with NaCl had an inhibitory effect on the intracellular accumulation of glutamate . The results indicate that P . aeruginosa PAO1 resists high NaCl concentrations, K+ accumulation and glutamate synthesis probably being the first mechanisms involved in adaptation to osmotic stress . Also is is demonstrated that betaine modulates intracellular glutamate levels in osmotically stressed P . aeruginosa PAO1.

Pharmacol Res, 1995 Jul-Aug, 32(1-2), 85 - 7
Antibacterial activity of liposomal amikacin against Pseudomonas aeruginosa in vitro; Antos M et al.; The influence of liposomal amikacin on Pseudomonas aeruginosa was studied . P . aeruginosa clinical isolates caused release of encapsulated amikacin from liposomes . The liposomal amikacin proved to be active as bactericidal agent after 3 h of incubation with P . aeruginosa . Incubation of P . aeruginosa with liposomal amikacin resulted in inhibition of the growth when equivalent of 2 MIC was added but not when equivalent of 1 MIC was added . Susceptibility of bacterial isolates to the liposomal amikacin varied with bacterial strain used, but generally encapsulation of amikacin did not enhance their antibacterial activity.

Zhonghua Wai Ke Za Zhi, 1995 Jul, 33(7), 390 - 2
{In vitro antibacterial activity of sulperazone on multi-resistant strains of bacteria from burn wounds}; Xu W et al.; Sulperazone (SLP), a combination of sulbactam (beta-lactamase inhibitor) with cefoperazone (CFP), was studied in vitro for its sensitivity to multi-resistant strains of bacteria isolated from burn wounds . The results showed that the sensitive rate of gram-negative bacteria to SLP was 77.3% (n = 163), higher than that of CFP (45.0%, n = 169) (P < 0.01) . The rate of pseudomonas aeruginosa which was common among the gram-negative bacteria was 88.9% (n = 45), much higher than that of CFP (71.7%, n = 46) (P < 0.05) . The rate of bacterium anitratum was 100%, and it was resistant to CFP (P < 0.01) . The sensitive rate of gram-positive bacteria to SLP was 37.5% (n = 128) but to CFP was 24.6% (n = 126) (P < 0.05) . The rate of staphylococcus aureus which was common in gram-positive bacteria was 42.6% (n = 61), much higher than that of CFP (21.3%, n = 61) (P < 0.05) . It is indicated that sulbactam inhibits most beta-lactamases produced by common bacterial pathogens and makes antibiotics restore the sensitivity to resistant strains . Sulperazone is promising in the treatment of burn infection.

J Antimicrob Chemother, 1995 Jul, 36(1), 41 - 52
Sequence analysis of two chromosomally mediated inducible beta-lactamases from Aeromonas sobria, strain 163a, one a class D penicillinase, the other an AmpC cephalosporinase; Walsh TR et al.; Two beta-lactamase genes from Aeromonas sobria, strain 163a, have been cloned and sequenced, one encoding a typical class C cephalosporinase, designated CepS, the other a class D penicillinase, designated AmpS . CepS is predicted to be a mature protein of 38 kDa with a pI value of 7.0 . The amino acid sequence of CepS is most similar to that of AmpC from Pseudomonas aeruginosa (54.7%) . AmpS is predicted to be a mature protein of 27 kDa with a pI value of 7.9 that mostly closely resembles BLAD from Klebsiella pneumoniae (42.2%), and OXA-1 from Escherichia coli (36.6%), beta-lactamases that are encoded by genes carried on multiresistant transposons . AmpS differs significantly from the other class D beta-lactamases in that it hydrolyses cloxacillin poorly and is inducible . Both genes exhibit a high overall GC content and possess a high NNC and NNG codon preference, similar to that of genes from Pseudomonas spp.

J Antimicrob Chemother, 1995 Jul, 36(1), 231 - 6
Effect on Pseudomonas aeruginosa alginate expression of direct plating and culture of fresh cystic fibrosis sputum on to pseudomonas isolation agar containing subinhibitory concentrations of roxithromycin and rifampicin; Dupont MJ et al.; The effects of subinhibitory concentrations of roxithromycin (16 mg/L) or rifampicin (16 mg/L) on alginate production by Pseudomanas aeruginosa were investigated . The weight of purified alginate from antibiotic-free cultures was significantly greater (52.5 +/- 24.0 mg, range 22.4-109.5), compared with alginate from cultures bacteria exposed to sub-MIC of roxithromycin (21.9 +/- 17.0, 0.0-42.1 (P < or = 0.037)) and to sub-MIC of rifampicin (28.6 +/- 15.0, 2.9-47.5 (P < or = 0.038)) . Chromatographic analysis of hydrolysed and chemically transformed sub-units of alginate revealed that the presence and the molar ratio of D-mannuronic acid and L-guluronic acid were not affected in the remnant alginate exposed to sub-MIC of roxithromycin in contrast to that in the remnant alginate exposed to sub-MIC of rifampicin.

Ann Pharmacother, 1995 Jul-Aug, 29(7-8), 704 - 6
Tobramycin-induced hypersensitivity reaction; Schretlen-Doherty JS et al.; OBJECTIVE: To report a case of a hypersensitivity reaction associated with the use of intravenous tobramycin in a patient with cystic fibrosis . CASE SUMMARY: An 18-year-old man was hospitalized for exacerbation of his cystic fibrosis . Tobramycin 125 mg iv q6h and ceftazidime 2 g iv q8h were administered through the patient's implantable access system in the left chest . Within seconds of receiving the third dose of tobramycin, the patient experienced shaking, his left arm turned white, and urticaria and pruritus were noted on the left side of the patient's chest . The patient had experienced a similar incident, accompanied by breathing difficulty, with intravenous tobramycin 4 years prior to this incident . The patient had been skin-tested for tobramycin allergy and had been desensitized and was receiving tobramycin since that time without incident . The patient's desensitization was maintained with tobramycin 160 mg/d hs by nebulization, but the drug had been discontinued by the patient 6 months prior to the latest event . DISCUSSION: Hypersensitivity reactions to aminoglycosides are unusual . Hypersensitivity to 1 aminoglycoside antibiotic frequently is associated with hypersensitivity to at least 1 other amino-glycoside . In patients who develop hypersensitivity to an amino-glycoside antibiotic, desensitization may be an effective alternative to changing therapy . CONCLUSIONS: Tobramycin is very important in the drug regimen for Pseudomonas aeruginosa infections in patients with cystic fibrosis . Effective desensitization can be maintained by daily administration of nebulized tobramycin.

Infect Control Hosp Epidemiol, 1995 Jul, 16(7), 417 - 8
An outbreak of Pseudomonas aeruginosa ventilator-associated respiratory infections due to contaminated food coloring dye--further evidence of the significance of gastric colonization preceding nosocomial pneumonia; File TM Jr et al.; An outbreak of ventilator-associated Pseudomonas aeruginosa respiratory infections in an intensive care unit of a teaching hospital was found to be associated with contaminated food coloring dye . Serotyping and bacteriocin typing indicated that the same strain of Pseudomonas was isolated from the food dye and from the respiratory cultures of the majority of patients . This observation lends credence to the importance of gastric colonization preceding pneumonia in ventilated patients.

Cornea, 1995 Jul, 14(4), 355 - 9
Scanning electron microscopy of the early host inflammatory response in experimental Pseudomonas keratitis and contact lens wear; Lawin-Brussel CA et al.; Because contact lens wear causes changes in tear film and corneal metabolism and can render the cornea susceptible to bacterial invasion, we examined the role of contact lens wear in Pseudomonas aeruginosa (P . aeruginosa) keratitis and its relation to the early defense mechanism, specifically whether the acute polymorphonuclear leukocyte (PMN) response is altered by contact lens wear . Thirty-three rabbit eyes were examined in an experimental model for P . aeruginosa keratitis . The development of bacterial invasion and PMN migration into the wound was studied during various time intervals in either the presence or absence of a soft hydrogel contact lens (SCL) . Scanning electron microscopy revealed massive PMN accumulation in the P . aeruginosa-inoculated corneas without SCL and some, but distinctively fewer, PMNs in the bacteria-inoculated eyes with SCL . These observations demonstrate that P . aeruginosa inoculation evokes massive PMN reaction and suggests that SCL wear actually delays this early host inflammatory response . Thus, SCL wear seems to act as a barrier for the PMNs that presumably derive from the tear film.

Laryngorhinootologie, 1995 Jul, 74(7), 456 - 9
{A rare case of malignant otitis external in a non-diabetic patient}; Anderhuber W et al.; One case of malignant external otitis in a non-diabetic patient is presented . Malignant external otitis is a rare but severe bacterial infection, caused by Pseudomonas aeruginosa, predominantly in elderly diabetic patients . The process starts in the external auditory canal and after crossing the cartilaginous-osseus junction invades the connective tissue, cartilage, bone, and nerves of the temporal bone and the surrounding parts of the base of the skull . The clinical syndrome is a severe, painful inflammation of the external auditory canal with edematous obstruction of the external canal and typical granulation tissue in the canal wall . Diagnostic criteria are pain, edema, exudate, granulations, microabscess, diabetes, old age, identification of Pseudomonas aeruginosa, and even cranial nerve involvement . Further important criteria are failure of local treatment and a positive Tc-99 scan demonstrating osteomyelitis of the temporal bone as a sign of connective tissue, cartilage, and bone invasion . In most cases there is also a positive radiograph or HR-CT of the base of the skull . Except for sequestrations, surgical treatment in malignant external otitis is impractical because of the deep penetration into the base of the skull and the lack of demarcation lines in this diffuse pathological process . Nowadays long term i.v . antibiotic therapy is preferred . In our case we applied Ceftazidim (Fortum) 2 g for 12 weeks twice a day . After this period the patient was completely cured . Our case demonstrates that malignant external otitis should be considered even in non-diabetic patients.

J Appl Bacteriol, 1995 Jul, 79(1), 94 - 102
Characterization of mucoid Pseudomonas aeruginosa strains isolated from technical water systems; Grobe S et al.; The occurrence of mucoid Pseudomonas aeruginosa strains was investigated in water samples and surface material from non-clinical aquatic environments . Ten of 81 environmental isolates displayed a mucoid colony type after incubation at 36 degrees C for 24 h on Pseudomonas Isolation Agar . The mucoid strains obtained exclusively from surfaces of technical water systems were characterized in terms of medium-dependent expression of mucoid colonial phenotype, exoenzyme profile, pigment production and O-antigen type . The mucoid strains secreted substantially higher quantities of carbohydrate and uronic acid-containing material compared to non-mucoid environmental isolates . Major slime components of the mucoid strains were identified as O-acetylated alginates that contained higher proportions of mannuronate than guluronate monomer residues and were composed of blocks of poly-mannuronate and poly-mannuronate/guluronate, whereas blocks of poly-guluronate were absent . The results suggest that surfaces in aquatic environments may represent a natural habitat for mucoid (i.e . alginate-overproducing) strains of Ps . aeruginosa with properties similar to clinical mucoid strains.

J Trauma, 1995 Jul, 39(1), 81 - 8; discussion 88-9
Beneficial effects of a bradykinin antagonist in a model of gram-negative sepsis; Ridings PC et al.; Activation of the kallikrein-kinin system in sepsis has long been recognized, but its role, beneficial or pathologic, has not been determined . Recently, however, specific bradykinin (BK) antagonists have become available and we sought to determine the effects of a BK antagonist, NPC17731, in a model of sepsis-induced acute lung injury (ALI) . METHODS: Anesthetized swine were studied for 5 hours, receiving a 1-hour infusion of saline (Controls) or live Pseudomonas aeruginosa (Septic untreated) . Treatment groups received a 5 mg/kg bolus of NPC17731 followed by a 1 mg/kg bolus hourly commencing either just before sepsis (Pretreatment) or 30 minutes following the onset of sepsis (Posttreatment) . RESULTS: Septic untreated animals showed a rapid, progressive decline in arterial PaO2 compared to controls, and this was significantly improved in both treatment groups . Bronchoalveolar lavage at 5 hours in both treatment groups also showed significant decreases in neutrophil (PMN) counts and protein content compared to untreated septic animals, indicating decreased PMN migration and alveolar-capillary membrane damage . Both treatment groups also showed reduced PMN sequestration in the lung compared to untreated animals, although PMNs did exhibit significant upregulation of PMN CD18 receptor expression and superoxide generation . CONCLUSIONS: These data imply a significant role for BK in the pathogenesis of sepsis-induced ALI . Use of a competitive BK antagonist significantly attenuated the development of ALI without inhibiting PMN activation . BK antagonists may be a useful adjunct in the armamentarium against sepsis-induced ALI.

J Bacteriol, 1995 Jul, 177(14), 4009 - 20
Analysis of the syrB and syrC genes of Pseudomonas syringae pv . syringae indicates that syringomycin is synthesized by a thiotemplate mechanism; Zhang JH et al.; The syrB and syrC genes are required for synthesis of syringomycin, a lipodepsipeptide phytotoxin produced by Pseudomonas syringae pv . syringae, and are induced by plant-derived signal molecules . A 4,842-bp chromosomal region containing the syrB and syrC genes of strain B301D was sequenced and characterized . The open reading frame (ORF) of syrB was 2,847 bp in length and was predicted to encode an approximately 105-kDa protein, SyrB, with 949 amino acids . Searches of databases revealed that SyrB shares homology with members of a superfamily of adenylate-forming enzymes involved in peptide antibiotic and siderophore synthesis in a diverse spectrum of microorganisms . SyrB exhibited the highest degree of overall similarity (56.4%) and identity (33.8%) with the first amino acid-activating domain of pyoverdin synthetase, PvdD, of Pseudomonas aeruginosa . The N-terminal portion of SyrB contained a domain of approximately 600 amino acids that resembles the amino acid-activating domains of thiotemplate-employing peptide synthetases . The SyrB domain contained six signature core sequences with the same order and spacing as observed in all known amino acid-activating domains involved in nonribosomal peptide synthesis . Core sequence 6 of SyrB, for example, was similar to the binding site for 4'-phosphopantetheine, a cofactor required for thioester formation . The syrC ORF (1,299 bp) was located 175 bp downstream of the syrB ORF . Analysis of the transcriptional and translational relationship between the syrB and syrC genes demonstrated that they are expressed independently . The syrC ORF was predicted to encode an approximately 48-kDa protein product of 433 amino acids which is 42 to 48% similar to a number of thioesterases, including fatty acid thioesterases, haloperoxidases, and acyltransferases, that contain a characteristic GXS (C) XG motif . In addition, a zinc-binding motif was found near the C terminus of SyrC . The data suggest that SyrB and SyrC function as peptide synthetases in a thiotemplate mechanism of syringomycin biosynthesis.

J Bacteriol, 1995 Jul, 177(14), 3998 - 4008
Virulence factors are released from Pseudomonas aeruginosa in association with membrane vesicles during normal growth and exposure to gentamicin: a novel mechanism of enzyme secretion; Kadurugamuwa JL et al.; Pseudomonas aeruginosa blebs-off membrane vesicles (MVs) into culture medium during normal growth . Release of these vesicles increased approximately threefold after exposure of the organism to four times the MIC of gentamicin . Natural and gentamicin-induced membrane vesicles (n-MVs and g-MVs and g-MVs, respectively) were isolated by filtration and differential centrifugation, and several of their biological activities were characterized . Electron microscopy of both n-MVs and g-MVs revealed that they were spherical bilayer MVs with a diameter of 50 to 150 nm . Immunoelectron microscopy and Western blot (immunoblot) analysis of the vesicles demonstrated the presence of B-band lipopolysaccharide (LPS), with a slightly higher proportion of B-band LPS in g-MVs than in n-MVs . A-band LPS was occasionally detected in g-MVs but not in n-MVs . In addition to LPS, several enzymes, such as phospholipase C, protease, hemolysin, and alkaline phosphatase, which are known to contribute to the pathogenicity of Pseudomonas infections were found to be present in both vesicle types . Both types of vesicles contained DNA, with a significantly higher content in g-MVs . These vesicles could thus play an important role in genetic transformation and disease by serving as a transport vehicle for DNA and virulence factors and are presumably involved in septic shock.

Zhonghua Yu Fang Yi Xue Za Zhi, 1995 Jul, 29(4), 222 - 4
{Preliminary studies on microbe-mediated N-nitrosamide synthesis}; Pan K et al.; Chemical synthesis of N-nitrosamide and influences on it by bacteria and fungi isolated from human gastric juice were studied with trace analysis method to explore the pathway of its endogenous formation . Results showed in synthesis of N-methyl-N-nitrosourea (MNU) with precursors of methylurea (0.42 mmol/L) and sodium nitrite (25 mmol/L) in a condition simulating human stomach, pH of the reaction system played an important role in the synthesis, the amount of synthetic chemical maximized at a pH of 1-3 and almost no synthesis was found at pH of 5-7 . A study on the ability to synthesize MNU catalyzed by bacteria isolated from the patients with stomach cancer living in a high-risk area showed its synthesis could be accelerated by Pseudomonas aeruginosa at pH of 6-7 with its catalyzing activity existed in heat liable component of living bacteria . This is the first report showing microorganisms to catalyze the formation of N-nitrosamide from its precursors.

Clin Infect Dis, 1995 Jul, 21(1), 194 - 5
Oral ciprofloxacin for treatment of infection following nail puncture wounds of the foot; Raz R et al.; From January 1990 to December 1993, 23 adults were hospitalized at our institution for treatment of foot infections that occurred following nail puncture wounds . All 23 patients had cellulitis, and 14 had signs of osteochondritis on a roentgenogram or a 99mTc bone scan . After undergoing surgical intervention that consisted of debridement, drainage of the pus, and exploration of the bones, patients received intravenous ciprofloxacin (400 mg b.i.d.) for 24 hours, followed by an oral regimen (750 mg b.i.d.) . Nine patients with cellulitis received oral therapy for 7 days, and the 14 patients with osteochondritis received oral therapy for 14 days . Isolates that were recovered included Pseudomonas aeruginosa (18 patients) and Staphylococcus aureus (2 patients); one patient had a mixed infection, and in two cases no pathogens were recovered . All of the isolates were susceptible to ciprofloxacin . All patients were cured, and none had reinfection . Our results show that foot infection following a nail puncture wound may be treated with oral ciprofloxacin (750 mg b.i.d.) for 7-14 days, provided that surgery is performed first.

J Med Assoc Thai, 1995 Jul, 78 Suppl 2, S105 - 7
Bacterial peritonitis associated with peritoneal dialysis; Sutcharitchan N et al.; A retrospective study on bacterial peritonitis was done in patients undergoing peritoneal dialysis in Nan Hospital from January 1990 to June 1993 . There were 154 patients . The average dialysis cycle was 52 and duration of dialysis was 50 hours . Bacterial peritonitis confirmed by positive culture was found in 13 patients (8.4%) . All infected patients had over 48 dialysis cycles and had the peritoneal catheter repositioned . The predominant bacteria were Pseudomonas aeruginosa and Klebsiella pneumoniae . One patient died of the infection . Meticulous care is needed to lower the risk of this complication.

Exp Anim, 1995 Jul, 44(3), 233 - 9
Survey of Pseudomonas aeruginosa contamination in human beings and laboratory animals; Urano T et al.; Several serotypes of Pseudomonas (P.) aeruginosa were isolated from the oral cavities of researchers, but no positive cases were found among the animals they had contacted or in the environment . These results indicated that researchers are not a source of P . aeruginosa infection for animals . However, P . aeruginosa was detected on the hands of researchers and animal caretakers after they finished their work . The same serotype of P . aeruginosa was found in the animals and the environment . These findings demonstrated that the researchers and the animal caretakers were contaminated with P . aeruginosa by the animals, and then became infective vehicles.

Am J Respir Crit Care Med, 1995 Jul, 152(1), 247 - 53
A dual-binding antibody to E- and L-selectin attenuates sepsis-induced lung injury; Ridings PC et al.; Many studies indicate a pivotal role for neutrophil adhesion in sepsis-associated lung injury . Neutrophil adhesion to endothelium depends on activation and expression of selectin and integrin adhesion receptors . We studied the effects of pretreatment with a dual-binding porcine anti-E- and anti-L-selectin monoclonal antibody (EL-246) on a porcine model of sepsis-induced lung injury . Four groups were studied for 5 h . Group 1 (control animals) received intravenous saline only . Group 2 (septic) received a 1-h infusion of Pseudomonas aeruginosa . Group 3 (EL-246 pretreatment) received EL-246 (1 mg/kg) prior to Pseudomonas infusion . Group 4 (EL-246 controls) received EL-246 infusion only . Group 2 animals showed rapid, significant decline in arterial pH and oxygen tension whereas, in Group 3, physiologic deterioration was significantly attenuated . Bronchoalveolar lavage at 5 h showed a significant increase in neutrophil count and protein content in Group 2 . Group 3, however, showed no significant differences in these parameters compared with control animals . Despite severe neutropenia, lung myeloperoxidase content at 5 h was significantly reduced in Group 3 compared with Group 2 . There was no significant difference in pulmonary and systemic hemodynamics between Groups 2 and 3 . Group 4 animals exhibited a transient neutropenia, but otherwise no other differences in measured parameters were found compared with Group 1 control animals . In conclusion, EL-246 significantly reduced neutrophil accumulation in lung and attenuated sepsis-induced lung injury, but failed to attenuate deranged pulmonary and systemic hemodynamics.(ABSTRACT TRUNCATED AT 250 WORDS)

Mol Microbiol, 1995 Jul, 17(2), 333 - 43
Multiple homologues of LuxR and LuxI control expression of virulence determinants and secondary metabolites through quorum sensing in Pseudomonas aeruginosa PAO1; Latifi A et al.; In Pseudomonas aeruginosa PAO1, expression of elastase is dependent upon an interaction between the positive transcriptional activator LasR and the auto-inducer molecule N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL), the synthesis of which is directed by LasI . Previously we have shown that in PAN067, an elastase-negative mutant of PAO1, elastase production can be restored to some extent by addition of exogenous N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) . Here we report that PAN067 is also defective in the production of alkaline protease, haemolysin, cyanide, pyocyanin and autoinducer(s) . As neither addition of exogenous OdDHL nor introduction of lasR restored PAN067 to the parental phenotype, we sought to complement PAN067 with PAO1 DNA . From a cosmid library, a 2 kb DNA fragment was identified which re-established production of autoinducer(s) and exoproducts in PAN067 . From the nucleotide sequence of this fragment, two genes termed rhIR and rhII were identified . RhII is responsible for autoinducer synthesis and shares 31% homology with LasI; RhIR has been previously identified in P . aeruginosa strain DSM2659 as a regulator of rhamnolipid biosynthesis and shares 28% identity with LasR . These data provide clear evidence that multiple families of quorum-sensing modulons interactively regulate gene expression in P . aeruginosa.

Mol Microbiol, 1995 Jul, 17(2), 323 - 32
Gradient of genomic diversity in the Pseudomonas aeruginosa chromosome; Romling U et al.; In 545 Pseudomonas aeruginosa strains, mainly collected from patients with cystic fibrosis, SpeI-DraI macrorestriction fragment length diversity was scanned for using probes of known map position on the P . aeruginosa PAO chromosome . Southern analysis of the 60 unrelated clones uncovered a gradient of macrorestriction fragment length polymorphisms (RFLPs) from the origin of replication towards the auxotroph-poor region of the P . aeruginosa genome . Linkage disequilibrium between macrorestriction sites was conserved in the P . aeruginosa population in the region encompassed by the rrn operons . The oriC-reactive SpeI fragment was conserved in nearly all isolates examined . Few fragment length classes were seen for the alg60-, algR- and toxA-encoding SpeI fragments . Fragment size varied within one class by up to 20 kb . Two probes from the auxotroph-poor region detected a broad size range for the SpeI fragment, suggesting extensive genomic diversity in these regions . Subclonal variation of fragment size was detected at all investigated loci in at least one of the analysed clones, but within one particular clone, SpeI-RFLPs were found at only few loci.

Antimicrob Agents Chemother, 1995 Jul, 39(7), 1467 - 71
Contribution of the C-8 substituent of DU-6859a, a new potent fluoroquinolone, to its activity against DNA gyrase mutants of Pseudomonas aeruginosa; Kitamura A et al.; Inhibitory effects of five quinolones against DNA gyrases purified from four quinolone-resistant clinical isolates of Pseudomonas aeruginosa and the quinolone-susceptible strain PAO1 were examined . All of the quinolone-resistant strains tested were found to be DNA gyrase mutants . The 50% inhibitory concentrations (IC50s) of the quinolones for these DNA gyrases roughly correlated with their MICs . Interestingly, gyrase inhibition by DU-6859a was found to be significantly less affected by these mutations that inhibition by other currently available quinolones . To assess the enhanced activity shown by DU-6859a, the effects of quinolones with altered substituents at the N-1, C-7, and C-8 positions of the quinolone ring of DU-6859a were tested . Measurement of MICs for four DNA gyrase mutants and IC50s for their purified DNA gyrases showed that removal of the C-8 chlorine of DU-6859a significantly increased MICs and IC50s for DNA gyrase mutants . However, no deleterious effects were observed when either the fluorine on the cyclopropyl substituent at the N-1 position or the cyclopropyl ring at the C-7 substituent was removed . Moreover, removal of the C-8 chlorine also increased the MIC for 19 of 20 quinolone-resistant clinical isolates . Our results led to the conclusion that DU-6859a is much more active against quinolone-resistant clinical isolates of P . aeruginosa than other currently available quinolones, probably because of its strong inhibitory effects against mutant quinolone-resistant DNA gyrases, and that the C-8 chlorine is necessary for these potent effects.

Antimicrob Agents Chemother, 1995 Jul, 39(7), 1462 - 6
Therapeutic efficacy of a polymyxin B-dextran 70 conjugate in experimental model of endotoxemia; Bucklin SE et al.; Numerous studies have suggested that lipopolysaccharide (LPS), a major component of the cell wall of gram-negative bacteria, is responsible for the initiation of gram-negative septic shock . Previously, others have designed therapeutic regimens to target the biologically active lipid A region of LPS by either neutralization of the biological properties of LPS or enhancement of clearance of this molecule . One such compound capable of neutralizing lipid A is the antibiotic polymyxin B . However, the clinical utility of polymyxin B is limited by its toxicity . We therefore covalently conjugated this antibiotic to the high-molecular-weight polysaccharide dextran 70, resulting in reduced toxicity of polymyxin B but retention of its endotoxin-neutralizing ability . The studies described in this report were designed to test the in vivo efficacy of this compound in an experimental animal model of gram-negative septic shock . Mice were administered graded doses of Escherichia coli or Pseudomonas aeruginosa along with D-galactosamine and the antibiotic imipenem . We had previously determined that antibiotic chemotherapy provides significant protection against E . coli-mediated lethality with smaller doses of bacteria; however, the antibiotic does not provide protection against larger doses of bacteria, but it is effective at killing the bacterial inoculum in vivo . Administration of the polymyxin B-dextran 70 conjugate provided significant protection when given with an antibiotic but was not effective by itself . A requirement for a pretreatment period prior to E . coli challenge was shown to depend upon the bacterial challenge dose . In other studies using this D-galactosamine sensitization model, we demonstrated that the lipid A-specific conjugate had no effect on lethality caused by staphylococcus aureus or tumor necrosis factor alpha . The results of these studies indicate that this compound is effective in preventing lethal gram-negative septic shock in mice and may be useful as a potential therapeutic agent in humans as well.

Proc Natl Sci Counc Repub China B, 1995 Jul, 19(3), 166 - 75
Production, purification and characterization of two proteinaceous hen-egg-white lysozyme inhibitors from Pseudomonas aeruginosa M-1001; Wang SL et al.; Two proteinaceous lysozyme inhibitors, hen-egg-white lysozyme inhibitors F-I and F-II, were isolated from the culture broth of a bacterial strain identified as Pseudomonas aeruginosa M-1001 . Maximum lysozyme inhibitory activity was obtained when the bacterium was grown aerobically in a medium consisting of 0.25% glucose, 0.25% beef extract, 0.25% polypepton, 1.0% sodium L-glutamate, and 1.0% soluble starch (pH 7.0) at 37 degrees C after 20-24 hrs . F-I and F-II were purified 20 and 7.5-fold, respectively, from the culture supernatant of P . aeruginosa M-1001 by ammonium sulfate fractionation, DEAE-Sepharose CL-6B column chromatography, and Sephacryl S-200 gel chromatography . The molecular weights of F-I and F-II were estimated to be about 57,000 and 33,000, by SDS-PAGE, respectively . F-I was stable in a pH range between 6 and 10 and below 50 degrees C . F-II was stable in a pH range between 6 and 11 and below 40 degrees C . Many Gram-positive bacteria were found to be inhibited by the crude lysozyme inhibitors.

Mol Biol (Mosk), 1995 Jul-Aug, 29(4), 801 - 12
{Recombination properties of the modified Pseudomonas aeruginosa RecA protein}; Namsaraev EA et al.; Gene recA from Pseudomonas aeruginosa was cloned into pUC19 vector under lacZ promoter . The expressed protein appeared to be modified, the aminoterminal part of deduced amino acid sequence of the RecAPa protein was found elongated by a polypeptide of 10 amino acids . The modified protein named RecA*Pa completely replaces RecAEc from E . coli in vivo recombination . In vitro RecA*Pa promotes the homologous strand transfer from a short linear duplex DNA fragment (346 bp) into circular single-stranded DNA (8196 n) being 5 times more active than RecAEc . However, when the length of dsDNA increased the difference between two proteins becomes negligible . To understand the reasons, some properties of RecA*Pa and RecAEc were compared . The former was shown to be more active both in binding to ssDNA in ssDNA-dependent ATP hydrolysis . The Rec*Pa protein showed also a high affinity to dsDNA, even at a physiological pH which is known to be unfavorable for RecAEc/dsDNA binding . However, both proteins equally catalyzed the dsDNA-dependent ATP hydrolysis; we suggest that this is crucial for a full-length DNA strand transfer recombination reaction.

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