Nosocomial spread of multi-resistant Klebsiella pneumoniae containing a plasmid encoding multiple beta-lactamases.
Six Klebsiella pneumoniae isolates that exhibited resistance to a wide spectrum of antibiotics were recovered from the intensive care units in the First Affiliated Hospital, Zhejiang University, Hangzhou, China. All isolates contained two plasmids of approximately 95 kb and 200 kb. The 95 kb plasmid was shown to be transferable by conjugation experiments. Isoelectric focusing patterns of the beta-lactamases extracted from the six transconjugants were identical, displaying five pI bands: 5.4, 7.75, 8.0, 8.2 and 8.4. The band corresponding to a pI of 7.75 could be inhibited by cloxacillin but not clavulanic acid, while the other bands could be inhibited by clavulanic acid but not cloxacillin. The 95 kb plasmid was digested with HindIII and a recombinant plasmid pT948 was obtained. The insert was found to contain blaDHA-1, regulatory gene ampR and an insertion element (IS26), which was downstream of blaDHA-1. PCR and DNA sequencing results confirmed that the 95 kb plasmid encoded at least four beta-lactamase genes: blaTEM-1, blaSHV-12), blaCTX-M-3 and blaDHA-1. Epidemiological typing by PFGE of the six clinical isolates of K. pneumoniae demonstrated identical genotypic patterns. In conclusion, all results indicated that the six multi-drug resistant clinical isolates of K. pneumoniae most probably originated from one clone and caused a localized epidemic in the intensive care units.
Wei
Ze-Qing
ZQ
Infectious Disease Dept, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Chen
Ya-Gang
YG
Infectious Disease Dept, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Yu
Yun-Song
YS
Infectious Disease Dept, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Lu
Wei-Xin
WX
Infectious Disease Dept, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Li
Lan-Juan
LJ
Infectious Disease Dept, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002681:China / Q000453:epidemiology; D003227:Conjugation, Genetic; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D004251:DNA Transposable Elements; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D007711:Klebsiella pneumoniae / Q000145:classification / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; C048795:AmpC beta-lactamases; D001618:beta-Lactamases