rCIM检测产碳青霉烯酶肠杆菌科细菌的应用价值研究

Application value of rCIM in the detection of carbapenemase-producing Enterobacteriaceae

目的研究快速碳青霉烯灭活试验(rapid carbapenem inactivation method,rCIM)检测产碳青霉烯酶肠杆菌科细菌(carbapenemase-producing Enterobacteriaceae,CPE)的临床价值。方法rCIM是将耐碳青霉烯肠杆菌科细菌(carbapenem-resistant Enterobacteriaceae,CRE)与美罗培南纸片孵育,离心所得上清液与指示菌株大肠埃希菌ATCC 25922进行二次孵育,并用浊度仪记录指示菌株ATCC25922的生长。将2016年1月-2018年9月临床分离的55株CREs,采用rCIM检测碳青霉烯酶,以PCR结果为金标准,同CNPt-Direct和改良碳青霉烯灭活试验(modified carbapenem inactivation method,mCIM)进行比较。并收集2018年10月-2019年5月临床分离的48株CREs进行前瞻性研究。结果回顾性分析中,rCIM检测碳青霉烯酶的灵敏性、特异性分别为97.1%、100%,高于mCIM和CNPt-Direct试验。rCIM与基因测序结果比对,一致性Kappa值为0.961。前瞻性研究中,rCIM检测碳青霉烯酶的灵敏性为96.4%,特异性为95%,一致性Kappa值为0.914。结论rCIM是一种快速(<3h)、经济、简便、可靠的筛选CPE菌株的方法。

Objective To study the clinical value of the rapid carbapenem inactivation method(rCIM)for the detection of carbapenemase-producing Enterobacteriaceae(CPE).Methods The rCIM consists of the incubation of carbapenem-resistant Enterobacteriaceae(CRE)with meropenem discs,and the supernatant obtained by centrifugation was incubated with the indicator strain E.coli ATCC25922 twice.Growth of the indicator strain ATCC25922 was monitored by a nephelometer.55 CREs were collected from clinical specimens from January 2016 to September 2018.Using PCR results as the gold standard,rCIM was used to detect carbapenemase and its results were compared with the CNPt-Direct test and the modified carbapenem inactivation method(mCIM).A prospective study of 48 CREs from clinical specimens from October 2018 to May 2019 was conducted.Results In retrospective analysis,the sensitivity and specificity of the rCIM were 97.1%and 100%,respectively,higher than the mCIM and the CNPt-Direct test.The rCIM results were compared with the results of gene sequencing,and the consistency Kappa value was 0.961.In the prospective study,the rCIM showed a sensitivity and specificity of 96.4%and 95%,respectively,and the consistency Kappa value is 0.914.Conclusion The rCIM is a fast(<3 h),inexpensive,simple and reliable method for screening CPEs.