Carriage of Plasmid-Mediated Colistin Resistance-1-Positive Escherichia coli in Humans, Animals, and Environment on Farms in Vietnam.
Nguyen PTL., Tran HTM., Tran HA., Pham TD., Luong TM., Nguyen TH., Nguyen LTP., Nguyen TTT., Hoang HTA., Nguyen C., Tran DN., Dang AD., Suzuki M., Le TV., Bañuls A-L., Choisy M., Van Doorn RH., Tran HH.
Plasmid-Mediated Colistin Resistance 1 (mcr-1) was first reported in 2015 and is a great concern to human health. In this study, we investigated the prevalence of mcr-1 and mcr-1-positive Escherichia coli (MCRPEC) and the association in infection status among various reservoirs connected to livestock. The study was conducted in 70 poultry and swine farms in a commune in Ha Nam province, northern Vietnam. Samples were collected from farmers, food animals, domestic animals, and farm environments (flies and wastewater) for polymerase chain reaction (PCR) screening for mcr-1 gene and species identification of PCR positive isolates. Among 379 obtained mcr-1 positives isolates, Escherichia coli was the major identified, varying from 50% (2/4) in dog feces to 100% (31/31) in humans feces isolates. The prevalence of MCRPEC was 14.4% (20/139), 49.7% (96/193), 31.3% (25/80), 36.7% (40/109), 26.9% (18/67), and 3.9% (2/51) in humans, chickens, pigs, flies, wastewater, and dogs, respectively. The study identified association between MCRPEC infection status in humans and flies (OR = 3.4), between flies and chickens (OR = 5.3), and between flies and pigs (OR = 9.0). Farmers' age and farm livestock unit were also associated factors of MCRPEC infection status in humans (OR = 5.1 and 1.05, respectively). These findings bring new knowledge on antibiotic resistance in livestock setting and important suggestions on potential role of flies in the transmission of mcr-1 resistance gene.