Prevalence and genotypes of carbapenemase-producing Enterobacteriaceae / 中国感染与化疗杂志

ABSTRACT

Objective To investigate the prevalence and main genotypes of carbapenemases in carbepenem‐resistant Enterobacteriaceae (CRE) .Methods A total of 114 strains of CRE were isolated in Shanghai Ruijin Hospital from May 2011 to June 2013 .The diameter of inhibition zone of imipemen or meropenem for these strains was not larger than 22 mm .PCR method was used to screen for the main carbapenemase genes (blaKPC ,blaIMP ,blaVIM ,blaOXA‐48 and blaNDM ) with previously described primers followed by nucleotide sequencing analysis . Conjugation experiments were performed to examine the transferability of plasmids .Pulsed‐field gel electrophoresis (PFGE) was used to show the relatedness of KPC‐2‐producing Enterobacteriaceae .Results Most of the 114 isolates were K lebsiella pneumoniae and Escherichia coli .Of the 114 isolates ,98 was positive for carbapenemases ,specifically ,78 blaKPC‐2‐positive ,15 blaIMP‐4‐positive ,2 blaIMP‐8‐positive ,1 positive for both blaKPC‐2 and blaIMP‐4 and 4 blaNDM‐1‐positive .None of the strains was positive for blaOXA‐48 or blaVIM .About 21 .4% (21/98) of the isolates were conjugated successfully .The 49 blaKPC‐2‐positive K .pneumoniae isolates were grouped into 12 types according to PFGE patterns .Majority (34/49) of these isolates belonged to the same type A .Conclusions BlaKPC‐2 was the primary epidemic genotype of Enterobacteriaceae in Ruijin Hospital ,followed by blaIMP‐4 .NDM‐1 carbapenemase was produced in 4 strains of CRE . Meanwhile , clonal spread of KPC‐2‐producing K . pneumoniae was observed in some departments of our hospital , such as surgical ICU , respiratory medicine and thoracic surgery . Appropriate measures should be taken timely and effectively to prevent the in‐hospital spread of resistant genes .