Detection and antimicrobial resistance profiles of Salmonella enterica recovered from house fly intestinal tracts and environments of selected broiler farms in Texas.

The entry of drug-resistant Salmonella enterica into the food supply is a challenge to public health and food safety. One emerging concern is the role of synanthropic insects for moving microbial pathogens throughout poultry production systems, where insects commonly thrive. We investigated the presence and phenotypic antimicrobial susceptibility of S. enterica from insect and environmental samples from broiler farms. Insects were collected throughout the broiler house and adjacent compost barn. Environmental samples (poultry feed, drinking water, fresh litter, and feces) were collected simultaneously (n = 80). Insect gastrointestinal tracts were dissected and pooled (n = 57). Recovered Salmonella isolates were serotyped and subjected to antimicrobial susceptibility testing against 14 medically important antimicrobials. Overall, six isolates were recovered from 137 total samples (4.4%): 3.5% (2/57) from adult house flies (Musca domestica), 15% (3/20) from poultry feed, and 4.8% (1/21) from litter. Salmonella Montevideo (16.7%; 1/6), Typhimurium (33.3%; 2/6), and Kentucky (50%, 3/6) were identified. All but one Salmonella isolate (83.3%; 5/6) demonstrated resistance to at least one antimicrobial. Further research should investigate movement patterns between broiler operations and food processing facilities to establish efficient biosecurity measures to prevent any instances of foodborne pathogen transmission into human food systems.