产碳青霉烯酶黏质沙雷菌的分子耐药机制研究

Study on the molecular resistance mechanism of carbapenem-producing Serratia marcescens

目的研究感染性黏质沙雷菌碳青霉烯酶基因分布与耐药相关性。方法回顾性分析本院2017年1月—2020年12月黏质沙雷菌耐药变迁,收集80株碳青霉烯类抗生素表型耐药的黏质沙雷菌,利用改良碳青霉烯灭活试验,碳青霉烯酶检测,PCR检测耐碳青霉烯类黏质沙雷菌的碳青霉烯酶分型。结果碳青霉烯类黏质沙雷菌检出率为40%~60%,其中在80株耐碳青霉烯类黏质沙雷菌菌株中,丝氨酸型碳青霉烯酶检出65株,金属β-内酰胺酶检出2株;胶体金法检出KPC型59株、OXA-48型10株、NDM型1株,同步检出KPC和NDM1株;PCR法检出KPC型58株、OXA-48型11株、NDM型1株,同步检出KPC和NDM 1株。结论本院黏质沙雷菌碳青霉烯类抗生素耐药率高,以KPC型流行为主;3种碳青霉烯酶的检测方法结果一致性好,有助于感控耐药机制的监测。

Objective To investigate the genes distribution of carbapenem-producing Serratia marcescens and the correlation of drug resistance.Methods Retrospective analysis was made on drug resistance changes of Serratia marcescens from January 2017 to December 2020 in our hospital.Eighty strains of Serratia marcescens with phenotype resistance to carbapenems were collected.Carbapenems inactivation test,carbapenase detection and PCR were used to detect the typing of carbapenems resistant Serratia marcescens.Results The detection rate of carbapenem-producing Serratia marcescens was between 40%and 60%.Among the 80 carbapenem-resistant strains,65 strains of Serine carbapenemase and 2 strains of metalβ-lactamase were detected.59 strains of KPC type,10 strains of OXA-48 type and 1 strain of NDM type were detected by colloidal gold method.Simultaneously,KPC and NDM1 strains were detected.58 strains of KPC,11 strains of OXA-48,1 strain of NDM and 1 strain of KPC and NDM were detected by PCR.Conclusion The carbapenem resistance rate of Serratia marcescens in our hospital was high,mainly KPC;the results of three carbapenemase detection methods were consistent,which is helpful to monitor the mechanism of drug resistance.