耐亚胺培南的肺炎克雷伯菌中碳青霉烯酶的表达情况

Expression of carbapenemase in Klebsiella pneumoniae resistant to imipenem

目的检测临床分离的耐亚胺培南肺炎克雷伯菌临床分布、耐药情况及碳青霉烯酶的表达情况,为临床合理使用抗生素提供依据。方法收集徐州3家三级医院微生物室培养出的非重复肺炎克雷伯菌,并根据药敏结果筛选对亚胺培南耐药的菌株,对耐药菌株采用改良Hodge实验检测碳青霉烯酶、IPM/EDTA组合纸片法检测金属酶表现型,采用PCR实验检测耐药菌株中bla_(KPC-2),bla_(CTX-M-15),bla_(VIM-1),bla_(IMP-4),bla_(NDM-1)和bla_(OXA-48)的表达情况。结果共收集107株非重复肺炎克雷伯菌,其中26株耐亚胺培南,耐亚胺培南菌株均为多重耐药菌株,对常见抗菌药物均为耐药;表现型结果26株耐亚胺培南菌株有23株改良Hodge实验阳性,阳性率为88.5%;6株组合纸片法阳性,阳性率为23.1%;PCR扩增具有碳青霉烯酶活性的相关基因:26株均检测到KPC-2酶基因,25株检测到CTX-M-15酶基因,8株检测到IMP-4酶基因,1株检测到NDM-1酶基因,1株检测到VIM-1酶基因,暂未扩增出OXA-48酶基因。结论本地区肺炎克雷伯菌耐亚胺培南形势严峻,产生β-内酰胺酶为其主要的耐药机制,KPC-2、CTX-M-15产生率较高,占主导地位,已经存在产NDM-1菌株,相关部门应注意预防其流行和传播。

Objective To detect the clinical distribution, drug resistance, and carbapenemase expression of clinically isolated imipenem-resistant Klebsiella pneumoniae to provide a basis for the rational use of antibiotics. Methods The non-repetitive Klebsiella pneumoniae cultured in the microbiology room of three tertiary hospitals in Xuzhou was collected, and the strains resistant to imipenem were screened based on the drug sensitivity results. The modified Hodge test was used to detect the carbapenems. The IPM/EDTA combined paper method was used to detect the metalloenzyme phenotype, and the expression of bla_(KPC-2), bla_(VIM), bla_(OXA-48), bla_(IMP), bla_(CTX-M) and bla_(NDM-1) in drug-resistant strains was detected by PCR experiments. Results A total of 107 non-repeated Klebsiella pneumoniae isolates were collected, of which 26 were imipenem-resistant. The imipenem-resistant strains were multi-drug resistant strains, which were resistant to common antibacterial drugs. 23 imipenem-resistant strains were positive for the modified Hodge test, with a positive rate of 88.5%;6 strains were positive for the combined disc method, with a positive rate of 23.1%;PCR-related genes with carbapenemase activity were identified: 26 strains with the KPC-2 encoding gene was detected, the CTX-M-15 encoding gene was detected in 25 strains, the IMP-4-encoding gene was detected in eight strains, the NDM-1 encoding gene was detected in one strain, and the VIM-1 encoding gene was detected in one strain. The OXA-48 gene was not detected. Conclusion The imipenem-resistant form of Klebsiella pneumoniae in this area is severe, and β-lactamase production is the main mechanism of resistance. KPC-2 and CTX-M-15 have high production rates, and they dominate. There are NDM-1 producing strains, and relevant departments should pay attention to preventing their epidemic and spread.