某院耐碳青霉烯类肠杆菌科细菌耐药基因分析

目的研究某院耐碳青霉烯类肠杆菌科细菌(CRE)在细菌耐药方面的分子流行病学特征,为CRE的防控提供依据。方法收集某院2013—2017年细菌室保存的CRE,对其进行多位点序列分型(MLST)、药敏试验、全基因序列测定,选取部分CRE中携带的碳青霉烯耐药基因进行基因环境分析。结果共收集62株CRE,成功复活51株;其中耐碳青霉烯类肺炎克雷伯菌(CRKP)30株,耐碳青霉烯类大肠埃希菌(CREC)9株,耐碳青霉烯类阴沟肠杆菌(CRECL)6株,耐碳青霉烯类其他肠杆菌6株。CRKP MLST主要包括3株ST147、2株ST11;CREC MLST主要包括3株ST167;CRECL MLST主要包括3株ST93、2株ST88。51株CRE对氨苄西林、头孢噻肟的耐药率最高,均为100%。耐碳青霉烯类耐药基因分布:1株携带blaKPC-2,14株携带blaIMP-4,18株携带blaNDM-1,22株携带blaNDM-5,2株携带blaNDM-9,10株携带blaOXA-1,10株携带blaOXA-10,2株携带blaOXA-23,2株携带blaOXA-66。分析blaNDM-1、blaNDM-5、blaNDM-9、blaIMP-4不同菌种的基因环境,发现几种耐药基因各自的基因环境都与已报道的基因环境相似,无明显的菌种间差异性。结论耐药基因通过水平传播能稳定存在于不同的CRE菌株中,对医院感染防控造成一定的威胁。

Resistance genes of carbapenem-resistant Enterobacteriaceae in a hospital

Objective To study the molecular epidemiological characteristics of drug resistance of carbapenem-resistant Enterobacteriaceae (CRE) in a hospital, and provide evidence for the prevention and control of CRE. Methods CRE stored in the bacterial laboratory of a hospital from 2013 to 2017 were collected and performed multilocus sequence typing (MLST), antimicrobial susceptibility testing as well as whole-genome sequencing, carbapenem resistance genes carried in some CRE strains were conducted gene environment analysis. Results A total of 62 strains of CRE were collected and 51 were successfully revived, including 30 strains of carbapenem-resistant Klebsiella pneumoniae(CRKP), 9 strains of carbapenem-resistant Escherichia coli (CREC),6 strains of carbapenem-resistant Enterobacter cloacae (CRECL), and 6 strains of other CRE. CRKP MLST mainly included 3 ST147 strains and 2 ST11 strains; CREC MLST mainly included 3 ST167 strains; CRECL MLST mainly included 3 ST93 strains and 2 ST88 strains. 51 strains of CRE showed the highest resistance to ampicillin and cefotaxime, all were 100%. Distribution of carbapenem resistance genes was follows:1, 14, 18, 22, 2,10, 10, 2, and 2 strains carried bla_KPC-2, bla_IMP-4, bla_NDM-1, bla_NDM-5, bla_NDM-9, bla_OXA-1, bla_OXA-10, bla_OXA-23, and bla_OXA-66 respectively. Genetic environment of bla_NDM-1, bla_NDM-5, bla_NDM-9, and bla_IMP-4 in different strains was analyzed, it was found that the genetic environment of several drug-resistant genes was similar to the previously reported genetic environment, there was no significant difference among strains. Conclusion Drug resistance genes can be stable in different CRE strains through horizontal transmission, which poses a threat to the prevention and control of healthcare-associated infection.