利奈唑胺耐药肠球菌感染危险因素及耐药机制分析

Risk factors for and the mechanism underlying linezolid-resistant Enterococcus infection

目的分析医院获得性和社区获得性利奈唑胺耐药肠球菌(LRE)感染的危险因素及其主要耐药机制。方法收集2018年9月—2020年12月分离的LRE菌株,根据LRE感染来源分为医院获得性和社区获得性,采用回顾性病例对照研究分别分析两种感染的危险因素。通过PCR和测序技术等方式检测菌株已知利奈唑胺耐药机制。结果共检出38株LRE。排除资料不完整病例,共纳入16例医院获得性LRE感染组和64例医院获得性利奈唑胺敏感肠球菌(LSE)感染对照组,17例社区获得性LRE感染组和68例社区获得性LSE感染对照组。医院获得性LRE感染单因素分析表明,气管插管、入住ICU、膀胱冲洗是主要危险因素;多因素分析表明气管插管是独立的危险因素。社区获得性LRE感染单因素分析表明,复数菌感染、低蛋白血症是主要危险因素;多因素分析表明低蛋白血症、复数菌感染是独立危险因素。医院获得性和社区获得性LRE耐药机制均主要为携带optrA基因(分别为61.5%和78.9%)。结论携带optrA基因为LRE主要耐药机制。医院获得性和社区获得性LRE感染危险因素分别为气管插管和低蛋白血症、复数菌感染。

Objective To investigate the risk factors of hospital-acquired and community-acquired linezolid-resistant Enterococcus(LRE)infection and explore the mechanisms of linezolid resistance.Methods LRE strains isolated from September 2018 to December 2020 were collected and assigned to community-acquired or hospital-acquired strains according to the source of LRE infection.Risk factors for hospital-acquired and community-acquired LRE infection were analyzed by retrospective case-control studies.The mechanism of linezolid resistance was examined by PCR and sequencing analysis.Results A total of 38 LRE strains were included in this analysis.A case control study was then conducted with 16 patients with hospital-acquired LRE infection and 64 controls with hospital-acquired linezolid-susceptible Enterococcus(LSE)infection,17 patients with community-acquired LRE infection cases and 68 controls with community-acquired LSE infection.Univariate analysis showed that endotracheal intubation,admission to ICU,and bladder irrigation were the main risk factors for hospital-acquired LRE infection.Multivariate analysis showed that endotracheal intubation was an independent risk factor.Univariate analysis showed that polymicrobial infection and hypoproteinemia were the main risk factors for community-acquired LRE infection,while multivariate analysis demonstrated that hypoproteinemia and polymicrobial infection were independent risk factors.The optrA gene was the main mechanism underlying hospital-acquired LRE resistance(61.5%),and community-acquired LRE resistance(78.9%).Conclusions The optrA gene is the main mechanism of linezolid resistance in LRE.The risk factors are different for hospital-acquired and community-acquired LRE infection.