Characterization of antibiotic resistance and carbapenemase-producing in carbapenem no-susceptibility Enterobacteriaceae from pediatric patients / 中华微生物学和免疫学杂志

ABSTRACT

Objective To analyze the antibiotic resistance of the carbapenem no-susceptibility Enterobacteriaceae isolated from pediatric patients and the resistant genes of carbapenemase-producing.Methods In all,46 carbapenem no-susceptibility Enterobacteriaceae strains were isolated from patients at Beijing Children's Hospital between January 2008 and December 2010.Agar dilution method recommended by the Clinical and Laboratory Standards Institute was used to examine the minimum inhibitory concentrations (MICs) of 14 antimicrobial agents.Phenotypic testing for carbapenemase-producing was conducted using Hodge test and double-disk synergy test.PCR was used to detect the expression of the carbapenemase-related genes KPC,GES,IMI/NMC-A,SME,IMP,VIM,GIM,SPM,SIM and OXA.WHONET5.6 was used to perform resistance analysis.Results Among 46 carbapenem no-susceptibility Enterobacteriaceae strains,26 (56.5％) were Klebsiella pneumoniae strains,13(28.3％ ) were Enterobacter cloacae and 7( 15.2％ ) were Escherichia coli.The rates of imipenem and meropenem no-susceptibility Klebsiella pneumoniae were 69.2％ and 80.8％,Enterobacter cloacae were 76.9％ and 100％ and Escherichia coli were 85.7％ and 100％,respectively.40(87.0％ ) strains were positive of Hodge test.41 (89.1％) strains were positive of doubledisk synergy test.38 (82.6％) were positive for the IMP genotype.The carbapenemase-related genes were not found in other 8 strains.Conclusion The prevalence of carbapenem no-susceptibility Enterobacteriaceae strains in Klebsiella pneumoniae isolates is relatively high in children.Resistance to imipenem was lower than that to meropenem from Klebsiella pneumoniae,Enterobacter cloacae and Escherichia coli strains.Many carbapenem no-susceptibility Enterobacteriaceae isolated from pediatric patients carry the blaIMP gene.No the KPC gene was found.