肺炎克雷伯杆菌ESBLs的基因类型及耐药性分析

目的了解大连部分医院肺炎克雷柏杆菌产ESBLs株的发生率、基因类型及耐药情况。方法纸片扩散法表型确证实验初步检测ESBLs产生株。PCR方法扩增耐药基因。二倍琼脂稀释法测定药物对菌株的最低抑菌浓度。结果44．29％的菌株检出产ESBLs。CTX—M型、TEM型、SHV型引物扩增阳性分别为26株，19株，7株；多为CTX—M型与TEM型或SHV型并存。产ESBLs株对亚胺培南敏感率达100％，对哌拉西林／他唑巴坦敏感率为67．74％，对头孢噻肟耐药率为80．65％，对头孢他啶耐药率为19．35％。结论本实验中产ESBLs菌株基因型以CTX—M型为主。亚胺培南可以认为是目前最有效的治疗产ESBLs菌感染的药物。

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.