重庆某三甲医院耐碳青霉烯类弗劳地枸橼酸杆菌感染危险因素分析及分子流行病学调查

Molecular epidemiological investigation of carbapenem-resistant Citrobacter freundii infections in a Grade 3 class A hospital in Chongqing

目的分析耐碳青霉烯类弗劳地枸橼酸杆菌(Carbapenem resistant Citrobacter freundii,CRCF)感染危险因素及分子流行病学特征。方法收集来自重庆医科大学附属第二医院2013年1月-2018年3月138例弗劳地枸橼酸杆菌感染患者临床资料,按照是否对碳青霉烯类抗生素耐药分为两组,CRCF组32例,非CRCF(Non-CRCF,NCRCF)组106例;用卡方检验及多因素logistic回归分析方法分析CRCF感染的危险因素;多位点序列分型(MLST)和脉冲场凝胶电泳(PFGE)分析细菌同源性。结果 138株弗劳地枸橼酸杆菌中CRCF检出率为23. 2%;多因素logistic回归分析显示肿瘤(OR=4. 057,95%CI=1. 574～10. 458,P=0. 004)和手术(OR=2. 938,95%CI=1. 160～7. 441,P=0. 023)是CRCF感染的独立危险因素;共有7个MLST克隆型,以ST22(n=9)和ST115(n=9)型多见,两个新的ST型已被PubMlst数据库收录并分别命名为ST115和ST116; PFGE与MLST分型结果基本保持一致。结论肿瘤和手术是CRCF感染的独立危险因素; ST22和ST115是CRCF感染的优势克隆型;应加强对CRCF的监测和控制,预防CRCF的播散流行。

Objective To analyze the risk factors and molecular epidemiological characteristics of infections with carbapenem-resistant Citrobacter freundii (CRCF). Methods The clinical data were collected from 138 patients with Citrobacter freundii infections admitted in our hospital between January, 2013 and March, 2018. Among these patients, CRCF were isolated from 32 patients and non-resistant Citrobacter freundii (nCRCF) from 106 patients. Chi-square test and multivariate logistic regression analysis were used to identify the clinical risk factors of CRCF, and multilocus sequence typing (MLST) and pulsed field gel electrophoresis (PFGE) were employed to analyze the homology of the CRCF isolates. Results Multivariate logistic regression analysis showed that surgery (OR=4.057, 95%CI=1.574-10.458, P=0.004) and tumor (OR=2.938, 95%CI=1.160-7.441,P=0.023) were independent risk factors for CRCF infection. Of the 32 CRCF isolates, 7 MLST clones were identified, among which ST22 (n=9) and ST115 (n=9) were the most prevalent; Two new STs were confirmed by the PubMlst database and named ST115 and ST116. The typing results of PFGE were basically consistent with the results of MLST. Conclusion Surgery and tumors are independent risk factors for CRCF infection, and ST22 and ST115 are the dominant clones in CRCF infection. The finding in this study urges effective measures for surveillance and control of CRCF infections.