Identification of an extensively drug-resistant Escherichia coli clinical strain harboring mcr-1 and blaNDM-1 in Korea

• Published in: Journal of antibiotics Vol. 73; no. 12; pp. 852 - 858
• Main Authors: Han, Sunghee, Kim, Jin Seok, Hong, Chae-Kyu, Park, Sang-Hun, Kim, Hee Soon, Yu, Jin Kyung, Park, Jungsun, Kim, Junyoung, Lee, Sang-Me, Oh, Young-Hee
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.12.2020; Nature Publishing Group
• Subjects: 45/23; 45/29; 45/77; 631/326/107; 631/326/2521; Antibiotic resistance; Antibiotics; Bacteriology; Biomedical and Life Sciences; Bioorganic Chemistry; Drug resistance; E coli; Genes; Life Sciences; Medicinal Chemistry; Microbiology; Organic Chemistry; Public health
• ISSN: 0021-8820; 1881-1469
• DOI: 10.1038/s41429-020-0350-1

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 CTX-M-55 gene, and the bla NDM-1 , bla TEM , 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.