Genotypes of β-lactamases produced by Klebsiella pneumoniae / 中华临床感染病杂志

ABSTRACT

Objective To investigate the genotypes of β-lactamases produced by Klebsiella pneumoniae.Methods Plasmid conjugation,PCR amplification,gene cloning and DNA sequencing,isoelectric focusing electrophoresis and extended-spectrum β-lactamase(ESBLs)confirmatory test were carried out for analyzing the encoding gene of β-lactamases in clinical strains of Klebsiella pneumoniae collected from hospital wards.Results Totally 75 clinical strains of Klebsiella pneumoniae were collected,in which 48 strains were confirmed to produce genotype of β-laetamases(64.0%),including 39 ESBLs-producing Btraim(52.0%).Among 48 strains,17 isolates(35.4%)carried 2 types of ESBLs genes,7(14.6%)carried 3 types of ESBL8 genes,and 5(10.4%)carried 4 types of ESBLs genes.CTX-M was the most comon type(30/48,62.5%),followed by TEM(26/48,54.2%)and SHV(25/48,52.1%).Among 9 isolates with DHA-1 AmpC β-laetamase,8 produced AmpC β-lactamases and ESBLs.Class A carbapenemase KPC-2 was produced in 3 isolates.False negative rate of ESBLs confirmatory test was 23.1%(9/39).Condusion Genotypes of β-lactamases produced by Klebsiella pneumoniae are complicated,which results in multi-drug resistance in clinic.