Enterobacteriaceae and Acinetobacter spp isolated from pigs reared with prophylactic use of penicillins or without antibiotics. Escherichia coli

The majority of antibiotics sold are administered to livestock, presumably promoting the development and spread of antibiotic resistance genes in food-borne pathogens such as Enterobacteriaceae producing extended spectrum beta-lactamases (ESBL). Pigs are major reservoirs of resistant Enterobacteriaceae that can reach humans through consumption of contaminated meat or vegetables grown in manure-fertilized soil. The major goal of the study was to characterize cefotaxime-resistant bacteria isolated from feed, faeces, manures and carcasses of quebecker pigs reared with penicillin-using or antibiotic-free husbandries. Samples were collected from sows during lactation and their piglets at five time points spanning the production cycle. The isolates were characterized by antibiotic susceptibility testing, whole genome sequencing and conjugation assays.