肺炎克雷伯杆菌ESBLs的基因类型及耐药性分析

Genotypes of ESBLS in klebsiella pneumonia and analysis of susceptibility testing

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。

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.