鲁西南地区13家医院213株耐碳青霉烯类肠杆菌目细菌流行病学及耐药基因特征

Epidemiological characteristics and drug resistance genes in 213 strains of carbapenem-resistant Enterobacteriaceae strains from 13 hospitals in southwest Shandong Province

目的 了解鲁西南地区耐碳青霉烯类肠杆菌目细菌(CRE)耐药基因及流行病学特点。方法 收集鲁西南地区13家医院2020年1月—2022年7月住院患者标本中分离到的CRE菌株,采用VITEK-MS质谱鉴定仪、VITEK-2 Compact全自动药敏仪,改良碳青霉烯灭活试验(mCIM)及碳青霉烯酶免疫层析法,最后筛选出213株菌株,进行聚合酶链反应(PCR)法检测耐药基因,并对10株携带双基因型菌株进行分析,对医院83株CRE菌株进行方法学之间的比较。结果 213株CRE主要分布科室在重症医学科、急诊监护室等;标本主要来源痰液、尿液、血液等;耐药率统计显示肺炎克雷伯菌耐药率高于大肠埃希菌。耐药基因分布特点:主要以bla_(KPC-2)、bla_(NDM-5)基因为主,其次为bla_(NDM-1)基因,10株双基因型CRE菌进行凝胶电泳分析,结果显示6株大肠埃希菌产不同bla_(NDM)基因同时携带mcr-1耐药基因,1株阴沟肠杆菌产bla_(NDM-1)同时携带mcr-9基因。对方法学的比较显示:mCIM+eCIM、免疫层析方法检测耐药基因型,KPC基因型两种方法无差异,对NDM基因型前者敏感度更高。结论 鲁西南地区CRE菌分离率最高的是产bla_(KPC-2)基因的肺炎克雷伯菌,其次是产bla_(NDM-5)基因的大肠埃希菌及产bla_(NDM-1)型阴沟肠杆菌。值得关注的是双基因型及少见基因型的检出,应引起感控部门的注意,以防耐药菌的传播和流行。

OBJECTIVE To investigate the drug resistance genes and epidemiological characteristics of the carbapen-em-resistant Enterobacteriaceae(CRE)strains from southwest Shandong Province.METHODS The CRE strains were isolated from the specimens of the patients who were hospitalized in 13 hospitals of southwest Shandong Province from Jan 2020 to Jul 2022.Totally 213 strains were finally screened out by means of VITEK-MS mass spectrometer,VITEK-2 Compact automatic drug susceptibility testing system,modified carbapenem inactivation test(mCIM)and carbapenem enzyme immunochromatography.The drug resistance genes were detected by poly-merase chain reaction(PCR),10 strains that carried with double genotypes were analyzed,and the methodological comparison was carried out for the 83 strains of CRE.RESULTS The 213 strains of CRE were mainly isolated from critical care medicine department and emergency care unit.Sputum,urine and blood were the major sources of specimens.Statistical analysis showed that the drug resistance rates of the Klebsiella pneumoniae strains was higher than that of the Escherichia coli strains.Bla KPC-2 and bla NDM-5 were dominant among the drug resistance genes,followed by blaNDM-1 gene.The result of gel electrophoresis analysis showed that among the 10 strains of CRE carrying with double genotypes,6 strains of E.coli produced blaNDM gene and carried with mcr-1 drug resist-ance gene,1 strain of Enterobacter cloacae produced blaNDM-1 and carried with mcr-9 gene.The methodological comparison indicated that among the drug resistance genotypes,there was no significant difference in the KPC genotype between the mCIM+eCIM and the immunochromatography,and the sensitivity of the mCIM+eCIM was higher for NDM genotype.CONCLUSION The isolation rate of bla KPC-2 gene-producing K.pneumoniae is the highest among the CRE strains isolated from southwest Shandong Province,followed by the blaNDM-5 gene-produ-cing E.coli and blaNDM-1-producing E.cloacae.The infection control department should attach great importance to the strains carrying with double genotypes and less common genotypes so as to prevent the transmission and prev-alence of drug-resistant strains.