Antimicrobial resistance: Study of the prevalence of colistin-resistant E. coli in chicken meat from the Czech retail stores

Colistin is the polymyxin antibiotic of last choice for the treatment of human infections of clinically resistant Gram-negative bacteria such as carbapenem-resistant Enterobacteriaceae (Tzouvelekis et al., 2012). Colistin is also used for therapeutic purposes in food-producing animals (Pardon et al., 2012). Until recently, colistin resistance was limited to chromosomal mutations (Landman et al., 2008). The situation changed in 2015 with the discovery of a plasmid-mediated mechanism of colistin resistance, the so-called mcr-1 gene, described in bacteria isolated from animals, raw meat and hospitalized patients in China (Liu et al., 2016). Since then, the mcr-1 gene has been reported worldwide in humans, animals and from environmental samples (Schwarz and Johnson, 2016). By 2019, 9 additional mcr genes encoding colistin resistance have been sequentially described in enterobacteria such as Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii (Carroll et al., 2019). There is limited information on the prevalence of mcr genes in foods available in the Czech Republic. This study was focused on assessing the prevalence rates of mcr-1 genes in retail chicken samples, which are mostly responsible for colistin resistance.CZ; PDF; efsa.focalpoint@mze.c