某中医院耐碳青霉烯类肠杆菌科细菌耐药表型及耐药基因分析

Analysis of drug-resistant phenotypes and drug-resistant genes of carbapenem-resistant Enterobacteriaceae in a traditional Chinese medicine hospital

目的分析成都中医药大学附属医院2016年—2018年耐碳青霉烯类肠杆菌科细菌(carbapenemresistant Enterobacteriaceae,CRE)的耐药表型、耐药基因型特点,为临床合理用药、有效抗感染治疗提供指导。方法选取成都中医药大学附属医院2016年1月—2018年12月分离出的2901株肠杆菌科细菌,采用微量肉汤稀释法和纸片扩散法筛选出CRE菌株,选择保种成功且临床资料详实的CRE进行碳青霉烯酶表型确证试验、耐药基因扩增和测序比对。结果2016年—2018年收集的101株CRE以肺炎克雷伯菌(73.27%,74/101)和大肠埃希菌(14.85%,15/101)为主,标本主要来源于痰液(63.37%,64/101)和导管尿(11.88%,12/101)。碳青霉烯酶表型检测结果为:改良Hodge试验阳性94株,阳性率93.07%;Carba NP试验阳性96株,阳性率95.05%;改良碳青霉烯酶灭活试验阳性98株,阳性率97.03%。101株CRE中有92株(91.01%)检出耐药基因,测序结果显示,66株(65.35%)携带blaKPC-2型基因,4株(3.96%)携带blaKPC-19型基因,9株(8.91%)携带blaNDM-1型基因,13株(12.87%)携带blaNDM-5型基因。未检出同时携带2种耐药基因的CRE菌株。耐碳青霉烯类肺炎克雷伯菌主要携带blaKPC-2基因(82.43%,61/74),耐碳青霉烯类大肠埃希菌主要携带blaNDM-5基因(86.67%,13/15),同国内主要流行基因型相符。结论该院近3年CRE菌株以携带blaKPC-2基因的肺炎克雷伯菌和携带blaNDM-5基因的大肠埃希菌为主。临床可根据此试验结果为指导,结合微生物室药物敏感性报告合理选择抗菌药物,以延缓耐药菌株的增长,预防多重耐药菌的医院传播。

Objective To analyze the drug-resistant phenotype and genotype characteristics of carbapenemresistant Enterobacteriaceae(CRE)in a traditional Chinese medicine hospital from 2016 to 2018,to provide guidance for clinical rational drug use and effective anti-infection treatment.Methods A total of 2901 Enterobacteriaceae bacteria strains isolated from January 2016 to December 2018 were selected,and CRE strains were screened by microdilution test and Kirby-Bauer methods.CRE strains with successful seed preservation and detailed clinical data were selected for carbapenemase phenotype confirmation test,drug-resistant gene amplification,and sequencing comparison.Results The 101 CRE strains collected between 2016 and 2018 were mainly Klebsiella pneumonia(73.27%,74/101)and Escherichia coli(14.85%,15/101),and the specimens were mainly from sputum(63.37%,64/101)and catheter urine(11.88%,12/101).The phenotypic test results of carbapenemase showed that 94 strains were positive in modified Hodge test,with a positive rate of 93.07%,96 strains were positive in Carba NP test,with a positive rate of 95.05%,and 98 strains were positive in modified carbapenem inactivation method test,with a positive rate of 97.03%.Drug-resistant genes were detected in 92(91.01%)of the 101 CRE strains,sequencing results showed that 66(65.35%)carried blaKPC-2 gene,4(3.96%)carried blaKPC-19 gene,9(8.91%)carried blaNDM-1 gene,and 13(12.87%)carried blaNDM-5 gene.No CRE strains carrying two resistance genes were detected.Among them,Klebsiella pneumoniae strains mainly carried blaKPC-2 gene(82.43%,61/74),and Escherichia coli strains mainly carried blaNDM-5 gene(86.67%,13/15),which were consistent with the main epidemic genotype in China.Conclusions In recent three years,the CRE strains in this hospital mainly included Klebsiella pneumoniae with blaKPC-2 gene and Escherichia coli with blaNDM-5 gene.According to the results of this test,we can reasonably select antimicrobial agents in combination with the drug sensitivity report from the microbial laboratory,so as to delay the growth of drug-resistant strains and prevent hospital transmission of multidrug-resistant bacteria.