耐碳青霉烯类肠杆菌目细菌药敏表型与产碳青霉烯酶酶型的相关性分析

Correlation analysis between carbapenem-resistant Enterobacterales susceptibility phenotypes and carbapenemase enzyme types

目的探讨分析耐碳青霉烯类肠杆菌目细菌(carbapenem-resistant Enterobacterales,CRE)药敏表型与产碳青霉烯酶酶型的相关性,探索流行菌株的耐药特征,为临床精准化合理用药提供可靠依据。方法收集2019年11月—2023年3月苏州大学附属第二医院分离保存的非重复CRE临床菌株共计102株,测定其对常见抗生素的最小抑菌浓度(minimal inhibitory concentration,MIC)或抑菌圈直径(KB值),用PCR法扩增CRE菌株中常见的碳青霉烯酶基因,通过多位点序列分型(multiple locus sequence typing,MLST)检测细菌的同源性和遗传性,统计分析相关患者临床资料。结果102株CRE对头孢他啶/阿维巴坦、多黏菌素和替加环素耐药率依次为20.6%、6.9%和5.9%。86株(84.3%)携带bla_(KPC-2),15株(14.7%)携带bla_(NDM),1株(1%)同时携带bla_(KPC-2)和bla_(NDM-1)。CRE中以肺炎克雷伯菌为主(90/102,88.2%),其次为大肠埃希菌(7/102,6.9%)。90株肺炎克雷伯菌MLST分型主要为ST11(61.1%)、ST15(24.4%)和ST700(3.3%),主要携带bla_(KPC-2)(94.4%)。ST11型耐碳青霉烯类肺炎克雷伯菌对头孢他啶/阿维巴坦、多黏菌素和替加环素耐药率依次为9.1%、7.3%和3.6%。未发现替加环素和多黏菌素药敏结果与产碳青霉烯酶酶型有相关性。结论头孢他啶/阿维巴坦、多黏菌素和替加环素3类抗生素能很好地互相弥补其耐药性。对于明确CRE感染的重症患者,建议临床尽快检测CRE菌株产碳青霉烯酶种类指导是否使用头孢他啶/阿维巴坦治疗。

Objective To investigate and analyze the correlation between the drug-susceptible phenotypes and carbapenemase enzyme types of carbapenem-resistant Enterobacterales(CRE),and to explore the drug resistance characteristics of epidemic strains,so as to provide a reliable basis for clinically precise and rational drug use.Methods A total of 102 non-duplicative CRE clinical strains isolated and preserved from the Second Affiliated Hospital of Soochow University from November 2019 to March 2023 were collected.The minimal inhibitory concentration(MIC)or the diameter of the inhibitory zone(K-B value)against common antibiotics was determined.The carbapenemase genes commonly found in CRE strains were amplified by PCR,and the homology and heritability of bacteria were detected by multiple locus sequence typing(MLST).Clinical data from relevant patients was collected and statistically analyzed.Results The resistance rates of 102 CRE strains to ceftazidime/avibactam,polymyxin and tigecycline were 20.6%,6.9%and 5.9%,respectively.86 strains(84.3%)carried bla_(KPC-2),15 strains(14.7%)carried bla_(NDM),and 1 strain(1%)carried bla_(KPC-2) and bla_(NDM-1).Among the CRE,Klebsiella pneumoniae was the dominant strain(90/102,88.2%),followed by Escherichia coli(7/102,6.9%).The MLST types of the 90 strains of Klebsiella pneumoniae were mainly ST11(61.1%),ST15(24.4%)and ST700(3.3%),mainly carrying bla_(KPC-2)(94.4%).The resistance rates of ST11 carbapenem-resistant Klebsiella pneumoniae to ceftazidime/avibactam,polymyxin and tigecycline were 9.1%,7.3%and 3.6%,respectively.No correlation between tigecycline and polymyxin susceptibility results and carbapenemase enzyme types was found.Conclusion The three classes of antibiotics,ceftazidime/avibactam,polymyxin and tigecycline,could well compensate for their resistance.For severe patients with confirmed CRE infection,it was recommended that the CRE strain be tested for carbapenemase-producing species as soon as possible and then guide whether to use ceftazidime/avibactam for treatment.