Department of Clinical Laboratory, First Affiliated Hospital of Wenzhou Medical University, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Wenzhou, Zhejiang Province, China.
Department of Clinical Laboratory, Children's Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China.
J Hosp Infect. 2023 Sep;139:168-174. doi: 10.1016/j.jhin.2023.06.017. Epub 2023 Jun 20.
This study aimed to explore differences in prevalence, resistance, biofilm-forming ability and virulence between carbapenem-non-susceptible and carbapenem-susceptible Enterobacter cloacae complex (ECC) in different clusters.
Ninety-one carbapenem-non-susceptible isolates and an equal number of carbapenem-susceptible isolates and their clinical information were collected from a university teaching hospital in China. The strains were divided into different clusters based on hsp60 analysis. The agar dilution method was used to determine the minimum inhibitory concentrations of common antibiotics. The crystal violet assay was used to measure biofilm-forming ability. The Galleria mellonella infection model and polymerase chain reaction of virulence genes were used to evaluate virulence.
The isolates were divided into 12 clusters based on hsp60 analysis. Cluster VIII accounted for a greater proportion of carbapenem-non-susceptible isolates than the other clusters. The same clusters exhibited different resistance rates in carbapenem-non-susceptible and carbapenem-susceptible isolates. Moreover, carbapenem-non-susceptible isolates carried fewer virulence genes than carbapenem-susceptible isolates, and carbapenem-non-susceptible isolates in cluster II in did not carry the detected virulence genes. Virulence of carbapenem-non-susceptible and carbapenem-susceptible isolates differed significantly in clusters I, III, VIII and IX, as evaluated using the G. mellonella infection model. Carbapenem-non-susceptible isolates in cluster VIII showed higher prevalence, resistance, biofilm-forming ability and pathogenicity compared with the other clusters.
The study findings indicate the need to identify subgroups of ECC, and provide better advice and guidance for the use of carbapenems.
本研究旨在探讨不同聚类中碳青霉烯类药物非敏感和敏感的阴沟肠杆菌复合体（ECC）之间流行率、耐药性、生物膜形成能力和毒力的差异。
从中国一所大学教学医院收集了 91 株碳青霉烯类药物非敏感株和等量的碳青霉烯类药物敏感株及其临床资料。根据 hsp60 分析将菌株分为不同的聚类。采用琼脂稀释法测定常见抗生素的最小抑菌浓度。结晶紫法测定生物膜形成能力。利用大蜡螟感染模型和毒力基因聚合酶链反应评估毒力。
根据 hsp60 分析，将分离株分为 12 个聚类。聚类 VIII 中碳青霉烯类药物非敏感株的比例高于其他聚类。相同的聚类在碳青霉烯类药物非敏感和敏感分离株中表现出不同的耐药率。此外，碳青霉烯类药物非敏感分离株携带的毒力基因少于碳青霉烯类药物敏感分离株，并且聚类 II 中的碳青霉烯类药物非敏感分离株不携带检测到的毒力基因。使用大蜡螟感染模型评估时，聚类 I、III、VIII 和 IX 中的碳青霉烯类药物非敏感和敏感分离株的毒力存在显著差异。聚类 VIII 中的碳青霉烯类药物非敏感分离株与其他聚类相比，其流行率、耐药性、生物膜形成能力和致病性更高。
研究结果表明，需要识别 ECC 的亚群，并为碳青霉烯类药物的使用提供更好的建议和指导。
