Genotypes of ESBLS in klebsiella pneumonia and analysis of susceptibility testing

Objective To investigate the prevalence of ESBLs in clinical isolates of klebsiella pneumonia and the genotypical characteristics and its susceptibility of ESBLs. Methods The ESBLs producing strains were detected by K-B disc diffusion method of phenotypic confirmatory test. PCR was performed using primer specific for blaCTX-M-1, blaCTX-M-9, blaSHV, blaTEM. MIC(minimal inhibitory concentration) were detected with double agar ailution method. Results 44.29% of Klebsiella pneumonia produced ESBLs.The 31 ESBLs producing strains were amplificated by four groups of primers, and 26 of the 31 strains were bla CTX-M positive, 19 of the 31 strains were blaTEM positive, 7 of the 31 strains were blaSHV positive. MIC results showed that the sensitivity of ESBLs producing strains to imipenem was 100%. And the susceptibility rate to piperacillin/tazobactam was 67.74%. The resistance rate to cefotaxime was 80.65%. Conclusion In this experiment, CTX-M was the most prevalent genotype of ESBLs. Imipenem is the most effective antibiotics to infections caused by ESBLs producing strains.