van genotype and molecular typing of clinical isolates of vancomycin-resistant Enterococcus / 中国感染与化疗杂志

ABSTRACT

Objective To determine the genotype and molecular typing of vancomycin-resistant Enterococcus (VRE).Methods Seventeen clinical isolates of VRE were collected in 2016.The strains were identified to species and confirmed by 16S rRNA sequencing.The minimum inhibitory concentration of antimicrobial agents was determined by microdilution method and agar dilution method.Multilocus sequence typing (MLST) was used for molecular typing.Results The VRE strains were confirmed as Enterococcusfaecium by 16S rRNA sequencing.All strains were resistant to vancomycin,but only 12 strains were resistant to teicoplanin.The vanA gene was identified in 13 of the 17 strains.The vanM gene was detected in 9 strains.Both vanA and vanM genes were identified in five of the 17 strains.Six MLST types were identified in the 17 strains,including ST78 (n=8),ST80 (n=4),ST555 (n=2),and one each for ST117,ST262 and ST341.Conclusions The van genotype was primarily vanA (76.5％) and vanM (52.9％) in clinical isolates of VRE.The VRE strains carrying both vanA and vanM were found for the first time.