Emergence of the mcr-1 colistin resistance gene in carbapenem-resistant Enterobacteriaceae

• Published in: The Lancet infectious diseases Vol. 16; no. 3; pp. 287 - 288
• Main Authors: Du, Hong, Chen, Liang, Tang, Yi-Wei, Kreiswirth, Barry N
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.03.2016; Elsevier Limited
• Subjects: Animals; Colistin - therapeutic use; CRE bacteria; E coli; Enterobacteriaceae - drug effects; Enterobacteriaceae Infections - drug therapy; Enterobacteriaceae Infections - immunology; Genes; Humans; Infectious Disease; Infectious diseases; Plasmids; Plasmids - immunology; Polymyxins - therapeutic use; Swine Diseases - drug therapy; China
• ISSN: 1473-3099; 1474-4457
• DOI: 10.1016/S1473-3099(16)00056-6

In response to this potential clinical problem, we retrospectively genotyped 17 colistin-resistant (European Committee on Antimicrobial Susceptibility Testing clinical breakpoint for resistance >2 μg/mL) Enterobacteriaceae isolates, including nine Salmonella spp, two Pantoea agglomerans, two E coli, and four K pneumoniae, collected between January, 2013, and November, 2015, from a tertiary hospital in Suzhou, China, for the presence of the mcr-1 gene by use of a previously described PCR assay.1 The mcr-1 gene was detected in four isolates (two E coli and two K pneumoniae; table), and sequencing of the PCR amplicons confirmed they all carry mcr-1. CTX-M-1 Minimum inhibitory concentration (μg/mL)*  Ampicillin >16 >16 >16 >16  Cefazolin >16 >16 >16 >16  Ceftazidime 16 8 >16 >16  Cefotaxime >32 >32 >32 >32  Cefepime >16 >16 >16 >16  Aztreonam >16 16 <=2 >16  Piperacillin >64 >64 >64 >64  Piperacillin-tazobactam <=4/4 <=4/4 >64/4 >64/4  Ampicillin-sulbactam 16/8 <=4/2 >16/8 >16/8  Amoxicillin-clavulanate 8/4 <=4/2 >16/8 >16/8  Imipenem <=1 <=1 >8 >8  Meropenem <=1 <=1 >8 >8  Amikacin <=8 <=8 <=8 <=8  Gentamicin <=2 >8 >8 >8  Ciprofloxacin >2 1 2 2  Levofloxacin >8 <=1 4 4  Moxifloxacin >4 2 >4 4  Co-trimoxazole >2/38 >2/38 >2/38 >2/38  Tetracycline >8 >8 >8 >8  Chloramphenicol >16 >16 >16 >16  Colistin >2 >2 >2 >2 Table Characteristics of mcr-1-harbouring isolates ESBL=extended-spectrum β-lactamase.