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ARS Home » Southeast Area » Athens, Georgia » U.S. National Poultry Research Center » Bacterial Epidemiology & Antimicrobial Resistance Research » Research » Publications at this Location » Publication #334693

Research Project: Monitoring and Molecular Characterization of Antimicrobial Resistance in Foodborne Bacteria

Location: Bacterial Epidemiology & Antimicrobial Resistance Research

Title: Whole Genome Sequencing and Plasmid Genomics of Antimicrobial Resistance – Salmonella’s mobile genetic elements and the antimicrobial resistance genes they carry

item MCMILLAN, ELIZABETH - University Of Georgia
item GUPTA, SUSHIM - Oakland Research Institute
item JOVE, THOMAS - Hospital And University Center Of Limoges
item Jackson, Charlene
item MCCLELLAND, MICHAEL - University Of California
item Frye, Jonathan

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/30/2016
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: With the emergence of antibiotic resistance (AR), multidrug resistance (MDR), and carbapenem resistant Enterobacteriaceae (CRE), the specter of widespread untreatable bacterial infections threatens human and animal health. The ability of these emerging resistances to transfer between bacteria on mobile genetic elements (MGEs) could cause the rapid establishment of MDR bacteria in animals leading to a foodborne risk to humans. To sample the diversity of AR genes and MGEs in Salmonella, we selected animal isolates collected from 1997-2011 by the National Antimicrobial Resistance Monitoring System (NARMS). The ~70,000 Salmonella in the collection were isolated from beef and dairy cattle, chicken, swine, turkey, their meat products, the processing environment, and from farms. To obtain the greatest variety of AR genes and MGEs, 193 isolates were chosen based on their resistance phenotypes, serovars, and PFGE patterns, resulting in 75 serovars with diverse PFGE patterns. Whole genome sequencing (WGS) and bioinformatics analysis was used to identify AR genes and MGEs. Most isolates had AR genes detected as well as MGEs such as plasmids, integrons, or both. The AR genes were often located on the MGEs and many were arranged into MDR cassettes of several contiguous AR genes. Some of the MGEs and AR genes have been previously found in Salmonella; however, they are arranged differently and have not previously been found in animal isolates, in the serovars analyzed, or in isolates from human infections. Together this demonstrates that different factors may be affecting the development and spread of MGEs encoding AR in Salmonella found in animals as compared to humans. The next step will be to identify the animal environments that lead to the development and spread of AR so that these can be targeted with interventions to reduce this risk to human and animal health.