Molecular characterisation of the metallo-beta-lactamase genes in imipenem-resistant Gram-negative bacteria from a university hospital in southern Taiwan.
In this study, 260 non-replicate imipenem-resistant Gram-negative bacteria isolated between January 2002 and December 2006 were subjected to a screening test for detection of metallo-beta-lactamase (MBL) using the Etest containing imipenem and ethylene diamine tetra-acetic acid (EDTA). Among the 260 strains, 123 (47.3%) appeared to produce MBL. Of these 123 strains, 113 (91.9%) were found by polymerase chain reaction (PCR) to carry MBL genes of types blaVIM-2, blaVIM-3, blaVIM-11 (blaVIM-11a), blaIMP-8 and novel blaIMP-24. One strain of Serratia marcescens harboured two MBL genes (blaVIM-11 and blaIMP-8) simultaneously. Of the 123 strains, 116 strains (94.3%) carrying the intI1 gene and 21 strains carrying integron-associated blaVIM-3, blaVIM-11 and blaIMP-8 genes were identified among Acinetobacter baumannii, Pseudomonas aeruginosa, Acinetobacter haemolyticus and S. marcescens. Using pulsed-field gel electrophoresis (PFGE) and Southern hybridisation with the blaVIM gene probe for I-CeuI-digested genomic DNA, P. aeruginosa 9527 strain harboured two class 1 integron-associated MBL genes in the chromosome, including blaVIM-3-orf2-aacA4 and novel bla(VIM-3)-orf2-aacA4-aadB-aacA4. This is the first description of the blaVIM-11 gene spreading among P. aeruginosa and A. baumannii strains in southern Taiwan. This finding suggests that clinical spread of this blaVIM-11 gene is a matter of great concern for carbapenem resistance in southern Taiwan.
Lee
Mei-Feng
MF
Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
Peng
Chien-Fang
CF
Hsu
Hui-Jine
HJ
Chen
Yen-Hsu
YH
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003428:Cross Infection / Q000382:microbiology; D004269:DNA, Bacterial / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000235:genetics*; D016905:Gram-Negative Bacterial Infections / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D006824:Hybridization, Genetic; D015378:Imipenem / Q000494:pharmacology*; D032023:Integrons / Q000235:genetics; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013624:Taiwan; D001618:beta-Lactamases / Q000235:genetics*
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D015378:Imipenem; D001618:beta-Lactamases