Publications

The emergence and dissemination of plasmid-borne mobile colistin resistance (mcr) genes have threatened the clinical use of colistin (polymyxin E), a last-resort antibiotic against multidrugresistant (MDR) Gram-negative bacterial pathogens. Although reports have documented the emergence of colistin resistance via chromosomal mutations in clinical pathogens, it was the discovery of mcr-1 in Escherichia coli isolated from a pig in China that indicated the possibility of the transmission of colistin resistance via lateral gene transfer. Subsequently, it became apparent that mcr-1 was not restricted to China and that this gene was spreading globally. Despite global attention, the emergence of mcr-1 and other mcr variants, their distribution and their impact on the treatment of complicated infections in countries with limited resources, weakened infrastructure and undeveloped antimicrobial stewardship still require further assessment. It can be argued that these countries might be the most vulnerable in the fight against MDR bacterial infections and, subsequently, the preservation of colistin efficacy is of paramount importance. Furthermore, the dissemination of mcr in vulnerable countries might serve as a reservoir for global dissemination of these genes. In this study, a survey was conducted to assess the availability of colistin for human therapeutics and veterinary and animal farming applications in Lebanon, a country with developing antimicrobial stewardship. The survey focused on different points in the antimicrobial resistance risk chain and mainly targeted (i) direct clinical exposure to colistin (amount of imported colistin for human cases) and (ii) potentially hazardous agricultural practices (colistin use in animal farming). The overall objective was to highlight factors that might be driving the spread of mcr and colistin resistance in Lebanon which has well-documented