Plasmid profiles of Klebsiella pneumoniae isolated from horses

Plasmid profiles of Klebsiella pneumoniae isolated from horses were examined. Thirty-nine strains of K. pneumoniae capsular type 1 (K1) isolated from cervical swabs of mares suffering from metritis, and from semen of stallions showed similar plasmid profile patterns, and all strains possessed a 125 megadaltons (Md) plasmid. There was no difference in plasmid profiles between the heavily-encapsulated and the less heavily-encapsulated strains of K. pneumoniae K1. Non-capsulated variants derived from the strains of K1 showed the same plasmid profile pattern as the parent strains. Plasmid profiles of K. pneumoniae other than K1 were various, and none of these strains possessed the 125 Md plasmid.     

Molecular typing of Klebsiella pneumoniae isolates from a neonatal intensive care unit

The epidemiological features of 60 multiresistant K. pneumoniae strains isolated from 1991 to 1995 in a neonatal ward are described. Antibiotic. Susceptibility testing and plasmid profile analysis were used as subtyping procedures. Antibiotic susceptibility typing was not informative enough since discrimination among isolates was typically poor. Plasmid profile analysis demonstrated that 58 out of 60 strains harboured one or more plasmid DNA bands, of different molecular weights ranging between 1.8 and 150 Mda. Small plasmids were best visualized after the alkaline lysis procedure, while large plasmids by the Kado and Liu method. A combination of plasmid patterns obtained by the two extraction procedures was used to define the final plasmid profile for each strain. Thirteen different plasmid profiles were identified among the collection of K. pneumoniae isolates from newborn patients of the same intensive care unit. The investigation showed that the strains were not responsible for a single outbreak.     

A case of Klebsiella pneumoniae endophthalmitis metastasized from prostatitis

A case of Klebsiella pneumoniae endophthalmitis metastasized from prostatitis is reported. A 58-year-old alcoholismic man with diabetic diathesis suffered from endophthalmitis which required enucleation of his left eye, when he interrupted the treatment of prostatitis. Metastatic bacterial endophthalmitis from urinary tract infection is rare.     

Extended-spectrum beta-lactamases from Klebsiella pneumoniae strains isolated at an Italian hospital

Eighteen strains of Klebsiella pneumoniae recently isolated from hospitalized patients were resistant or moderately resistant to oxyimino-cephalosporins (ceftazidime and/or cefotaxime), aztreonam, cefoxitin and all but one were susceptible to imipenem. Analysis of enzymes produced by these clinical isolates revealed a wide pattern of extended-spectrum beta-lactamases. All isolates produced one or more beta-lactamases that were characterized preliminarily by their isoelectric point. Strains isolated early were from patients in the Intensive Care Unit and produced an ES beta-lactamase with an apparent pI of 7.6, whereas the later isolates were from surgical and medical wards of the same hospital and produced ES beta-lactamases with apparent pI of 8.2 and 8.4, respectively. This suggests the emergence of SHV-5 and MIR-1 beta-lactamases in our hospital. Agarose gel electrophoresis of plasmid DNA revealed the presence of a similar plasmid of approximate size 60 Kb in all isolates.     

Purification and biochemical characterization of gentisate 1,2-dioxygenase from Klebsiella pneumoniae M5a1

Fas Ag is a cell surface molecule that transduces the signal for apoptosis. Since mesangial cells (MC) play important roles in regulating glomerulonephritis, we investigated regulatory mechanisms of Fas system in MC. Fas Ag was expressed on MC from normal mice. This Fas Ag expression was down-regulated by inducing proliferation with platelet-derived growth factor or 18% fetal bovine serum, but was reversed when cycloheximide was added to the culture. Anti-Fas Ab alone did not induce apoptosis in MC, but MC became susceptible to apoptosis induced by anti-Fas Ab is actinomycin D or cycloheximide was added. Noteworthy findings are that mRNA of Fas ligand was expressed in MC. Taken together, MC appears to control the proliferation by regulating Fas system-mediated apoptosis, at least in part, through an autoregulatory mechanism with Fas Ag Fas ligand expressed on their own MC.     

Salicylate-enhanced exposure of Klebsiella pneumoniae subcapsular components

Viable and non-viable cells in coronary and internal thoracic arteries, collected at autopsy 7-24 h post-mortem from individuals 15-81 years of age, were detected using the fixable fluoroprobes 5-chloromethylfluorescein diacetate (green) and ethidium homodimer-1 (orange/red). Viability status of individual endothelial and smooth muscle cells was confirmed by simultaneous autoradiographic detection of incorporated [3H]glucosamine. Twenty-five percent of coronary and 42% of internal thoracic arteries contained viable cells up to 24 h following death. For the majority of viable vessels the mean percentage of viable cells ranged between 60 and 80% with no significant difference between coronary and internal thoracic arteries and no relationship with either age of the donor or with time to autopsy. Non-viable cells were usually distributed fairly evenly amongst viable cells but this pattern could not be assumed. In a number of vessels non-viable cells were variably clustered in different regions of vessel wall. These findings confirm that vessels sampled at autopsy can be used for metabolic studies with the caveat that assessment of cell viability is a necessary prerequisite for interpretation of results.     

Extended-spectrum beta-lactamases in clinical isolates of Klebsiella pneumoniae from Zagreb, Croatia

Forty clinical isolates of Klebsiella pneumoniae, from various clinical specimens, with reduced susceptibility to ceftazidime, were tested for extended-spectrum beta-lactamase (ESBL) production. ESBL production was demonstrated by an 8-fold reduction in the minimum inhibitory concentration (MIC) of ceftazidime combined with clavulanate (2 mg/L) compared to ceftazidime alone in all strains. The aim of this investigation was the biochemical and molecular characterization of the ESBL produced by K. pneumoniae strains and their Escherichia coli transconjugants. Transfer of ceftazidime resistance was demonstrated in 23 of 40 strains. Thirteen strains produced an ESBL with the isoelectric point of 8.2 which was encoded by a self-transferable multiresistance plasmid of 150 kb. The substrate profile was similar to that of the SHV-5 isolated initially in Chile. Seven of these 12 strains had an additional TEM beta-lactamase. Six isolates and their transconjugants produced a plasmid-encoded ESBL with an isoelectric point close to 5.4. The remaining 21 strains produced an ESBL with an isoelectric point of 7.6 (thus probably SHV-2) which was encoded on a plasmid transferable to E. coli in 4 strains only. Four of those strains possessed an additional plasmid encoded TEM beta-lactamase with an isoelectric point close to 5.4. The transconjugants harbored a multiresistance plasmid of 150 kb. Thus SHV-2 and SHV-5 enzymes appear to have been the most common ESBLs in K. pneumoniae from Zagreb during 1994-1995.     

Klebsiella pneumoniae panophthalmitis: a possible complication of endoscopic variceal injection sclerotherapy

Complication of endoscopic variceal injection sclerotherapy for esophageal variceal hemorrhage is not unusual. However, sclerotherapy complicated panophthalmitis was never reported before. We report such an unusual complication and discuss its possible mechanism and treatment.     

Study of an outbreak of cefoxitin-resistant Klebsiella pneumoniae in a general hospital

During a 3-month period, six Klebsiella pneumoniae isolates resistant to cefoxitin and penicillin-inhibitor combinations were derived from patients in the intensive care unit of a hospital in Athens, Greece. Enterobacterial repetitive intergenic consensus PCR and pulsed-field gel electrophoresis provided evidence of the clonal origin of the isolates. Conventional techniques and ribotyping were inadequate in proving that the isolates were related. Resistance was due to a plasmidic class C beta-lactamase.     

Production and characterization of guluronate lyase from Klebsiella pneumoniae for applications in seaweed biotechnology

Cultures of Klebsiella pneumoniae fermenting sodium alginate produce an extracellular guluronate-specific alginate lyase. This enzyme production was studied in stirred-tank fermentors. Different alginate substrates gave moderate differences in growth and enzyme yield. Alginates with low guluronic content gave reduced biomass but favored enzyme production. Low molecular weight (down to DPn approximately 270) also favored enzyme production. Excessive depolymerization of substrates occurred during heat sterilization of culture media. The enzyme was characterized by its specificity and sensitivity to pH, salt, and calcium. Improved yields of viable protoplasts were documented for Laminaria digitata (Huds.) Lamour.     

AI-2 Key Enzyme S-Ribosylhomocysteinase from Strain Klebsiella pneumoniae CICC 10011 Producing 2,3-Butanediol

S-Ribosylhomocysteinase(LuxS) is the key enzyme in the synthetic pathway of a quorum sensing autoinducer AI-2. LuxS from a 2,3-butanediol produced strain Klebisella pneumoniae CICC 10011 was cloned and characterized. The luxS gene is composed of 540 bp with 172 amino acids encoded. The Km value for S-ribosylhomocysteine(SRH) was (27+1) μmol/L, kcat was (0.112+0.004) s-1 and kcat/Km was 4.4×103 L·mol-1· s-1 at 25℃. LuxS was activated by divalent metal ions, the highest activity was detected with Co2+ form, followed by Mg2+, Ba2+, Mn2+, Fe2+ and Ca2+, and activation constant for Co2+ is (16+2) μmol/L.     

Identification of the plasmid-mobilization potential of the strain Klebsiella pneumoniae ozenae KIIIA isolated from a polluted aquatic environment

Gro Harlem Brundtland, who became Director General of the World Health Organization in July 1998, has created a small revolution at the WHO headquarters in Geneva. She is in the process of changing how WHO works, how it interacts with other parts of the United Nations system, and how it enlists ministries, whole governments, universities, and other private organizations to improve health in the world. Here, the Editor describes the reorganization, the new people and resources, and prospects for setting a precedent in United Nations reform.     

Energy-dependent accumulation of fluoroquinolones in quinolone-resistant Klebsiella pneumoniae strains

The intracellular accumulation of norfloxacin and pefloxacin in Klebsiella pneumoniae was evaluated. The roles of lipopolysaccharide, capsule, and outer membrane proteins were not important for the intrabacterial accumulation of fluoroquinolones in isogenic strains with known outer membrane alterations. In fluoroquinolone-resistant clinical isolates also expressing GyrA alterations, an active efflux leading to decreased accumulation of the drugs enhanced their resistance to these agents.     

Molecular markers for differentiation of multiresistant Klebsiella pneumoniae isolates in a pediatric hospital

OBJECTIVE: To study the spread of extended-spectrum beta-lactamase-producing, but aminoglycoside-susceptible, Klebsiella pneumoniae strains in our hospital over an 8-month period, by using two genotypic markers. DESIGN: Ribotyping (using two endonucleases) and randomly amplified polymorphic DNA analysis (RAPD; using two different 10-mer primers) were applied to the epidemiological typing of clinical K pneumoniae isolates from stools, ileal fluid, or urine of hospitalized children. SETTING AND PATIENTS: The surgical intensive-care ward (S1: 9 patients, 17 isolates), surgical unit (S2: 2 patients, 2 isolates), and gastroenterology ward (GE: 1 patient, 1 isolate) of the Robert Debré Hospital of Paris, France. RESULTS: Ribotyping of the 20 clinical isolates, the type strain of the species, and two epidemiologically unrelated isolates with EcoRI and HindIII revealed 6 and 5 different patterns, respectively. Six ribotypes were identified by using these two enzymes. RAPD generated 6 distinct patterns, in complete agreement with ribotyping. Our genotypic results showed that 11 patients from wards S1, S2, and GE harbored genotypically related strains, suggesting nosocomial transmission and cross-colonization between and within the three wards. CONCLUSIONS: Ribotyping and RAPD appear to be reliable methods for distinguishing K pneumoniae strains. The spread of one strain of K pneumoniae in different units of our hospital was demonstrated by both methods. However, RAPD has the advantage of simplicity and rapidity conferred by polymerase chain reaction.     

Molecular epidemiology of extended-spectrum beta-lactamase-producing Klebsiella pneumoniae isolates in a district hospital in Taiwan

Thirty-one of 104 clinical isolates of Klebsiella pneumoniae collected over a period of 8 months were found to be putative extended-spectrum beta-lactamase (ESBL) producers. Isoelectric focusing and an iodine overlay agar method were used for preliminary identification of the ESBLs. They were further identified by DNA sequencing. Seventy-one percent of the isolates were found to produce SHV-5. The variation in the ESBL patterns of these isolates was slight, with only five patterns being identified. The strains were typed by pulsed-field gel electrophoresis (PFGE), and 16 different genotypes were identified. When the PFGE patterns were analyzed by the algorithmic clustering method called the unweighted-pair group method using arithmetic averages, five clusters were found. However, significant genetic variations were found among 11 isolates and between each cluster. A plasmid of 36 kb was found in all clinical isolates and in the transconjugants. Our results indicate that the increase in the number of ESBL-producing K. pneumoniae isolates in this hospital is due mainly to the dissemination of a resistance plasmid rather than to the clonal spread of a few epidemic strains.     

Synergism in biofilm formation between Salmonella enteritidis and a nitrogen-fixing strain of Klebsiella pneumoniae

A laboratory reactor, which simulates biofilm formation in water pipes, was used to study interactions in biofilm formation between a nitrogen-fixing strain of Klebsiella pneumoniae and Salmonella enteritidis. The level of attachment of Salm. enteritidis was higher in the binar biofilm than in the single species biofilm. In the initial colonization phase the binary biofilm contained a much higher proportion of metabolically active cells than in single species biofilms formed by either Salm. enteritidis or Kl. pneumoniae. When a pulse of Salm. enteritidis was passed over an already established biofilm of Kl. pneumoniae it rapidly became integrated into the biofilm, from where it was subsequently released into the water column, along with Kl. pneumoniae. Klebsiella pneumoniae fixed nitrogen in the presence of Salm. enteritidis in both types of biofilm.     

Antibodies to Klebsiella pneumoniae lipopolysaccharide in patients with ankylosing spondylitis

The role of microbial lipopolysaccharides (LPS) in the aetiopathogenesis of ankylosing spondylitis (AS) is a matter of continuing debate. In this study, class-specific IgG, IgA and IgM antibodies against Klebsiella pneumoniae, Escherichia coli, Salmonella typhimurium and Salmonella enteritidis LPS were measured by enzyme-linked immunosorbent assay (ELISA) in 100 AS patients, 50 rheumatoid arthritis (RA) patients and 50 healthy control subjects. The AS patients had significantly elevated levels of IgG and IgA antibodies against K. pneumoniae LPS (P < 0.001) and IgA antibodies against E. coli LPS (P < 0.05) compared to healthy controls. There were no significant elevations of antibody levels against S. typhimurium and S. enteritidis in the three study groups. In addition, there was a correlation between IgG and IgA anti-K. pneumoniae LPS antibody levels and the acute-phase reactant C-reactive protein (P < 0.001).     

Effects of aspirin on arylamine N-acetyltransferase activity in Klebsiella pneumoniae

This study was designed to assess the effects of aspirin on arylamine N-acetyltransferase (NAT) activities in the bacterium Klebsiella pneumoniae using high performance liquid chromatography to measure the acetylation of 2-aminofluorene (2-AF) with or without aspirin. Cytosols or suspensions of K. pneumoniae with or without specific concentrations of aspirin co-treatment showed different percentages of 2-AF acetylation. The data indicated that there was decreased NAT activity associated with increased levels of aspirin in K. pneumoniae cytosols and in intact bacteria. For the cytosol examination, the apparent values of Km and Vmax decreased 0.59- and 0.58-fold after co-treated with 40 microM aspirin, respectively, for 2-AF. For the intact bacteria examination, the apparent values of Km and Vmax decreased 0.60- and 0.67-fold after co-treated with 40 microM aspirin, respectively, for 2-AF. This report is the first demonstration to show that aspirin can decrease N-acetyltransferase activity in the bacterium K. pneumoniae.