ESBLs Phenotype and Genotype Analysis of Klebsiella and Escherichia coli

OBJECTIVE To explore the phenotype and genotype of Klebsiella and Escherichia coli producing extended-spectrum β-lactamases(ESBLs).METHODS The producing ESBLs strains in 110 E.coli and 94 Klebsiella isolates were determined according to disk diffusion test,recommended by NCCLS and the drug-resistant genes such as TEM,SHV,CTX-M-1,CTX-M-2 and CTX-M-9 were detected by PCR and sequencing.RESULTS The producing ESBLs rates were 36.2%,42.7% and 39.7% in Klebsiella,E.coli,and in both two strains,respectively.The positive rate in detecting ESBLs by CTX and CTX/CLAV was higher(66.7%);the negative rates were 68.1% in E.coli,64.7% in Klebsiella when using CAZ alone and CAZ/CLAV.The rates of TEM,SHV,CTX-M-1,CTX-M-2 and CTX-M-9 were 54.3%,38.3%,21.0%,24.7% and 70.4%,respectively,in producing ESBLs isolations.The CTX-M genotype was predominant,(91.4%);the isolations(71.6%) contained more than two resistance genes.CONCLUSIONS More attention should be payed on ESBLs producing E.coli and K.pneumoniae strains.