Salmonella spp. and Extended-Spectrum Cephalosporin-Resistant Escherichia coli Frequently Contaminate Broiler Chicken Transport Cages of an Organic Production Company

Antimicrobial resistant bacteria in retail meat pose a health hazard to the public, as does contamination of these products with Salmonella. Our aim was to determine the prevalence of Salmonella as well as Escherichia coli expressing AmpC and extended-spectrum beta-lactamase (ESBL) resistance phenotypes contaminating broiler transport cages and fresh, retail ground chicken meat. Sterile gauze sponges were used to collect duplicate cage floor samples from transport trailers that deliver market-ready birds to a single organic poultry-processing facility. With the exception of the first visit (n=25), 50 duplicate cage floor samples were collected using moistened sterile gauze sponges on each of nine weekly visits during May, June, and July 2013. Additionally, fresh, retail ground chicken meat was sampled at each weekly visit from an on-site retail store located at the same processing facility. A total of 425 cage swabs and 72 ground chicken aliquots from 24 retail packages were collected and screened for the presence of Salmonella as well as E. coli expressing resistance to extended-spectrum cephalosporins using selective culture. We recovered Salmonella from 26.1% of cage swab samples and 2.8% of retail meat samples. E. coli expressing AmpC and ESBL resistance phenotypes were recovered from 84.9% and 22.6% of cage swabs and 77.8% and 11.1% of fresh, retail ground meat samples, respectively. Our results suggest that transport cages could potentially act as a source of broiler exposure to both Salmonella and enteric bacteria resistant to important antimicrobial drugs as they are transported for entry into the food supply as fresh, retail meat products.