Implications of Foodborne Bacteria on Human Health: Isolation and Antibiotic Resistance of Salmonella enterica and Campylobater spp. on Retail Chicken Sold in California

Overuse of antibiotics contributes to antimicrobial resistance (AMR), which continues to be a growing threat to human health. In the United States, industrial food animal production (IFAP) is a formidable driver for antibiotic use. Prior work has focused on the link between antimicrobial use in poultry and human AMR infections. Common foodborne pathogens such as Salmonella enterica (S. enterica) along with Campylobacter coli (C. coli) and Campylobacter jejuni (C. jejuni) are commonly associated with human gastroenteritis. However, it has been shown that these pathogens are capable of causing disease outside of the gastrointestinal tract, specifically urinary tract infections (UTIs). Due to their ubiquitous nature on raw and undercooked poultry, these pathogens serve as an overlooked source of UTIs for individuals with exposure to retail poultry. AMR has become a major public health concern and predicted to cause more than 10 million AMR related deaths. In 2015, California passed senate bill 27 (SB-27), the first bill of its kind to restrict the use of antimicrobial drugs in the poultry industry. Implemented on January 1, 2018, the legislation places poultry farmers’ ability to administer “medically important antimicrobial drugs” to their livestock under the discretionary supervision of licensed veterinarians. The legislation is intended to reduce antibiotic usage in the poultry industry for non-therapeutic purposes such as preventative measures, promoting weight gain, or improving feed efficiency. This study, therefore, examined the relationship between the implementation of SB-27 and rates of AMR in Salmonella and Campylobacter species present on retail chicken produced and sold in California. Samples were collected weekly from September 2017 through April 2018. Collection sizes ranged from 30-70 samples. S. enterica, C. coli, and C. jejuni were selected and isolated from the meat. Confirmed isolates were then subjected to AMR testing. S. enterica was found on 15.2% of samples and Campylobacter spp. on 28.0% of samples. Resistance was found in 14 of 15 antibiotics tested on Salmonella positive samples. Resistance was found on 7 of 7 antibiotics tested on Campylobacter positive samples. In future analyses, the AMR profiles of the retail poultry isolates will be compared to those of clinical isolates from UTI patients diagnosed in proximity to the outlets from which poultry samples were collected. This comparison probes the validity of the foodborne urinary tract infection (FUTI) paradigm for Salmonella and Campylobacter, which posits the significance of foodborne reservoirs of pathogenic bacteria leading to the acquisition of urinary tract infection