First Report of the Plasmid-Mediated Colistin Resistance Gene mcr-1 in Escherichia coli ST405 Isolated from Wildlife in Bejaia, Algeria.

BACKGROUND: The aim of the present study was to screen for the presence of mcr-1 gene in Enterobacteriaceae isolated from Barbary macaques (Macaca sylvanus) in Algeria.

MATERIALS AND METHODS: From January to April 2016, a total of 86 fresh stool samples from Barbary macaques were collected in the Toudja forest (Bejaia, Algeria). After isolation, the isolates were identified by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. Antibiotic susceptibility was determined by disk diffusion method, and minimum inhibitory concentration (MIC) of colistin was determined by E-test. Polymerase chain reaction (PCR) and sequencing were used to identify mcr-1gene. The sequence type (ST) was done using multilocus sequence typing. Phylogenetic groups of Escherichia coli and the presence of virulence genes were determined by PCR. Transfer of mcr-1 and extended-spectrum β-lactamase genes was assessed by conjugation and transformation experiments.

RESULTS: E. coli M076 isolate was found resistant to colistin with a MIC of 4 mg/L and to other antibiotic families, including β-lactams, aminoglycosides, and fluoroquinolones. PCR and sequencing revealed that this isolate harbored the mcr-1, blaCTX-M-15 , blaTEM-1 , and qnrB19 genes. This isolate was assigned to ST405, belonged to phylogroup D, and contains only one virulence gene fyuA (siderophore uptake receptor). Neither transconjugants nor transformants were obtained for this isolate.

CONCLUSION: In this study, we report the detection of mcr-1 gene producing E. coli from wild animals.