(507d) Antibiotic Probiotics Reduce Salmonella Enterica in Pre-Harvest Poultry

Chicken has become the most popular type of meat in the world. In the US, per capita consumption has doubled to nearly 90 lbs/year since 1980. The value of chicken broilers produced during 2014 was $32.7 billion, up 6 percent from 2013.

Chicken is also the leading cause of salmonella food poisoning. Despite the vast arsenal of technologies employed to control salmonella in poultry products, these products are the most significant sources of Salmonella enterica that sickens people. In the US, Salmonella enterica is the leading cause of foodborne disease outbreaks, with approximately 1 million infections annually, and calculated health care and lost productivity costs exceeding $3 billion every year. These disconcerting numbers may increase after the FDA-directed phasing out of the use of medically important antimicrobials in food animals for production purposes.

Herein, we report on a new antibiotic technology that can reduce Salmonella enterica in poultry. We have engineered the probiotic strain E. coli Nissle 1917 to produce and secrete the antimicrobial peptide microcin J25. Employing synthetic biology techniques we engineered a DNA promoter for strong, constitutive expression of the peptide. In vitro tests demonstrate the efficacy of the system against Salmonella enterica. The reported animal experiments provide strong proof-of-concept results. Salmonella enterica clear the ceca of poultry faster than in negative control experiments. Approximately 97% lower salmonella carriage is measured in the treated group, by end of the experiment, 14 days post-challenge, compared to the untreated group.

Probiotic bacteria are generally regarded as safe to consume, are bile-resistant and can plausibly be modified to produce many out of the thousands of antimicrobial peptides now known. The reported systems may provide a foundation for platforms to launch antimicrobials against any one of many gastrointestinal tract pathogens, including ones that are multi-drug resistant.