High prevalence of VanB2 vancomycin-resistant Enterococcus faecium in Taiwan.
Thirty-six VanB glycopeptide-resistant Enterococcus faecium isolates were collected from patients in five different hospitals in Taiwan. The vancomycin resistance genes were amplified by the long vanB PCR, which amplifies the 6,373-bp vanB gene cluster including the vanR(B2), vanS(B2), vanY(B2), vanW(B2), vanH(B2), vanB2, and vanX(B2) genes. The deduced amino acid sequences were found to be 95 to 98% homologous to those of the vanB1 gene cluster: VanR(B1), 97%; VanS(B1), 97%; VanY(B1), 96%; VanH(B1), 95%; VanB1, 96%; and VanX(B1), 98%. Restriction enzyme analysis of the long vanB PCR products revealed that all 36 isolates had the same vanB2-specific pattern. DNA sequence analysis of the vanB2 gene, which is a D-Ala-D-Lac ligase gene, revealed that none of the 36 sequences were identical to the previously published vanB2 sequence. Thirty-one isolates had 1 nucleotide different from the published vanB2 sequence. The sequences of the other five isolates differed from the published vanB2 sequence by 2 or 3 nucleotides. Four isolates with a low or moderate resistance to vancomycin (MIC = 4 to 32 microg/ml) were found to have the same leucine-to-methionine change at amino acid position 308 of the vanB2 gene. The genomic DNAs of all 36 isolates were digested with SmaI and then typed by pulsed-field gel electrophoresis (PFGE). Eight different PFGE types (I to VIII) were observed, and type I was found to be prevalent in all hospitals examined in this study. This result suggests that intra- and interhospital dissemination of this E. faecium strain has occurred in Taiwan.
Lu
J J
JJ
Division of Clinical Pathology and Experimental Pathology, Department of Pathology, Tri-Service General Hospital and National Defense Medical Center, No. 325, Section 2, Chengkung Rd., Taipei 114, Taiwan, Republic of China. jjl@ndmctsgh.edu.tw
Perng
C L
CL
Ho
M F
MF
Chiueh
T S
TS
Lee
W H
WH
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D005810:Multigene Family; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D017422:Sequence Analysis, DNA; D013624:Taiwan / Q000453:epidemiology; D017334:Teicoplanin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C079913:VanB protein, Enterococcus; D017334:Teicoplanin; D014640:Vancomycin