Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Research Project #430777

Research Project: Analysis of Virulence and Antibiotic Resistance Mechanisms of Salmonella and Development of Intervention Strategies

Location: Food Safety and Enteric Pathogens Research

Project Number: 5030-32000-113-000-D
Project Type: In-House Appropriated

Start Date: Dec 10, 2015
End Date: Dec 10, 2020

Our objectives target three factors that influence Salmonella colonization, pathogenesis, and persistence. These factors include virulence mechanisms of Salmonella, the tactical response from the host, and interactions with the microbiota residing within the host. Our systematic approach integrates these research areas into three complementary objectives: Objective 1: Investigate the impact of antibiotic usage on influencing Salmonella virulence mechanisms and enhancing antibiotic resistance. Objective 2: Develop novel non-antibiotic intervention strategies such as beneficial microbes and vaccines to limit Salmonella colonization, persistence and shedding. Objective 3: Evaluate immune networks and identify porcine genes for their relationship with the host microbiota to reduce Salmonella colonization, persistence, and shedding.

The common goal of each research objective is to identify targets for the development of novel antibiotic alternatives to reduce both Salmonella transmission through the food chain and antibiotic usage on the farm. To accomplish these objectives, experiments are planned to examine molecular mechanisms in Salmonella that are influenced by antimicrobial resistance and host colonization, elucidate porcine genetic pathways associated with decreased Salmonella colonization, and investigate interactions between Salmonella and host microbiota that affect Salmonella colonization and persistence. We plan to: 1) identify antibiotics that enhance virulence properties in multidrug-resistant (MDR) Salmonella, as well as those antibiotics that have no effect on virulence; this useful information will aide producers and veterinarians when determining antibiotic therapy for the treatment of infectious diseases; 2) genome sequence and transcriptionally analyze MDR Salmonella isolates that phenotypically respond to antibiotic exposure; 3) measure the effect chlortetracycline treatment has on limiting or exacerbating Salmonella shedding and altering the microbiota in swine; 4) evaluate a cross-protective Salmonella vaccine in turkeys for reduction of Salmonella colonization and transmission; 5) systematically characterize changes in the porcine immune response and gastrointestinal microbiota during Salmonella colonization; 6) assess biotherapeutic treatments as alternatives to antibiotics for treatment of swine colonized with Salmonella.