Chicken meat as reservoir of E. Coli carrying MCR-1 genes in South America
The detection and rapid spread of colistin-resistant Enterobacteriaceae carrying the mcr-1 gene has created an urgent need to strengthen surveillance. As part of a local investigation into the presence of colistin-resistant bacteria, Brazilian researchers collected 41 chicken samples from markets in Sao Paulo and tested them for susceptibility to polymixin B and colistin and for the presence of the MCR-1 gene, which confers resistance to colistin. They found eight clonally unrelated colistin-resistant E coli isolates carrying MCR-1.
The authors report that most of the E coli isolates exhibited a multidrug-resistant phenotype and carried additional genes conferring resistance to aminoglycosides, quinolones, sulphonamide, and tetracyclines. In addition, they found the presence of IncX4-type plasmids, which have been implicated in global dissemination of the gene, in five of the isolates.
This is the first time that colistin-resistant E. coli carrying the mcr-1 gene is identified in commercial chicken meat, in Latin America.
See also: Emergence of mcr-1 in China