College of Public Health Sciences (CPHS), Chulalongkorn University, Bangkok 10330, Thailand.
Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand.
J Appl Microbiol. 2023 Oct 4;134(10). doi: 10.1093/jambio/lxad229.
Carbapenem resistance among Enterobacteriaceae is a serious threat to humans worldwide. This study aims to evaluate the phenotypic and genotypic characterization of carbapenemase-producing Enterobacter cloacae complex (ECC) retrieved from water sources in the central part of Thailand.
Samples were collected from water bodies surrounding farms and communities in central Thailand. The species were identified by using MALDI-TOF MS. The minimum inhibitory concentration (MIC) and antibiotic susceptibility were determined. The carbapenemase-producing genes were detected by PCR and whole genome sequencing (WGS). ECC with chromosome-encoded blaIMI-1 carbapenemase were detected. These isolates were resistant to last-resort antibiotics such as carbapenems and colistin as well as penicillin. In addition, all blaIMI-1 genes isolated from this study were found to be associated with chromosomally integrated Xer-dependent integrative mobile elements (IMEXs).
These findings highlight the diversity and dissemination of carbapenemases-producing Enterobacterales in environmental sources. With the increasing detection of carbapenemase genes worldwide, we should be aware of the blaIMI-producing E. cloacae complex with a high resistance profile and the ability to mobilize within the environment.
肠杆菌科的碳青霉烯类耐药性是全球人类面临的严重威胁。本研究旨在评估从泰国中部水源中分离出的产碳青霉烯酶阴沟肠杆菌复合群（ECC）的表型和基因型特征。
从泰国中部农场和社区周围的水体中采集样本。使用 MALDI-TOF MS 进行物种鉴定。测定最小抑菌浓度（MIC）和抗生素敏感性。通过 PCR 和全基因组测序（WGS）检测产碳青霉烯酶基因。检测到染色体编码 blaIMI-1 碳青霉烯酶的 ECC。这些分离株对包括碳青霉烯类和黏菌素在内的最后手段抗生素以及青霉素具有耐药性。此外，本研究中分离出的所有 blaIMI-1 基因均与染色体整合的 Xer 依赖性整合移动元件（IMEXs）相关。
这些发现强调了环境来源中产碳青霉烯酶肠杆菌科的多样性和传播。随着全球碳青霉烯酶基因检测的增加，我们应该意识到具有高耐药谱和在环境中移动能力的产 blaIMI 阴沟肠杆菌复合群。
