Genotypes of extended-spectrum beta-lactamases in clinical isolates of Klebsiella pneumoniae

Objective To explore the extended-spectrum beta-lactamases(ESBLs) genotypes of clinical Klebsiella pneumoniae strains isolated from our hospital.Methods A total of 83 clinical strains of Klebsiella pneumoniae were collected.ESBLs-producing isolates were confirmed through phenotypic confirmatory tests as recommended by double-disk diffusion test,and PCR was used to determine the distribution of antibiotic resistant genes CTX-M,TEM and SHV in plasmids.Results Of 83 isolates,76(91.6%) were confirmed as ESBLs-producing strains,in which 41 isolates were verified to carry the three antibiotic resistant genes.CTX-M was the most common one(78.1%),followed by TEM(43.9%) and SHV(34.2%) present in plasmids.Among these 41 ESBLs-producing isolates,different types of resistant genes were found to exist in plasmids as combinations.Conclusion CTX-M and SHV are the most common resistant genotypes in ESBLs-producing Klebsiella pneumoniae strains isolated from our hospital,and their distribution is complicated.