Infectious Diseases Team, Seoul Metropolitan Government Research Institute of Public Health and Environment, Gyeonggi-do, Republic of Korea.
Department of Bioscience and Biotechnology, Konkuk University, Seoul, Republic of Korea.
J Antibiot (Tokyo). 2020 Dec;73(12):852-858. doi: 10.1038/s41429-020-0350-1. Epub 2020 Jul 14.
The development of colistin resistance in carbapenem-resistant strains poses a serious public health problem. In this study, we collected 249 carbapenem-resistant Escherichia coli isolates from patients in Seoul in 2018, and screened all isolates for colistin resistance and for the presence of mobile colistin resistance (mcr) genes. Colistin-resistant strains were further analyzed using multilocus sequence typing, antimicrobial susceptibility testing, detection of antibiotic resistance determinants, plasmid transconjugation, and whole-genome sequencing. Three of the 249 carbapenem-resistant isolates were resistant to colistin, and mcr-1 was detected in one isolate (SECR18-0888), which belonged to sequence type 156 and was resistant to all antibiotics tested except tigecycline. The mcr-1.1 gene was located on an ~62 kb self-transferable IncI2 plasmid along with the bla gene, and the bla, bla, qepA1, and rmtB genes were additionally detected in SECR18-0888. As an extensively drug-resistant E. coli strain producing MCR-1 and NDM-1 was identified in Korea for the first time, continued monitoring of colistin resistance in carbapenem-resistant Enterobacteriaceae should be reinforced.
碳青霉烯类耐药菌株中粘菌素耐药性的发展构成了严重的公共卫生问题。本研究收集了 2018 年首尔地区 249 株耐碳青霉烯类大肠埃希菌分离株，对所有分离株进行了粘菌素耐药性和移动性粘菌素耐药（mcr）基因筛查。对粘菌素耐药株进一步进行多位点序列分型、药敏试验、抗生素耐药决定因素检测、质粒转导和全基因组测序分析。249 株耐碳青霉烯类大肠埃希菌中有 3 株对粘菌素耐药，其中一株（SECR18-0888）检出 mcr-1，属于 156 型序列，除替加环素外，对所有检测的抗生素均耐药。mcr-1.1 基因位于一个约 62kb 的可自我转移的 IncI2 质粒上，同时还检测到 bla、bla、qepA1 和 rmtB 基因。这是韩国首次发现同时产 MCR-1 和 NDM-1 的广泛耐药性大肠埃希菌，应加强对碳青霉烯类耐药肠杆菌科中粘菌素耐药性的监测。
