ARS | Publication request: ACSSuT Multi-Drug Resistance Among Salmonella Isolates of Animal Origin

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 13, 2008
Publication Date: August 24, 2008
Citation: Cray, P.J., Frye, J.G., Haro, J.H. 2008. Acssut multi-drug resistance among salmonella isolates of animal origin. International Conference on Emerging Antimicrobial Agents in Veterinary Medicine. August 24-28,2008. Prague, Czech Republic. 44.

Technical Abstract: BACKGROUND: Multi-drug resistant (MDR) Salmonella Typhimurium DT104 (DT104) emerged in the mid-1990’s in humans and animals with infection resulting in increased morbidity and mortality. DT104 was characterized by resistance to Ampicillin, Chloramphenicol, Streptomycin, Sulfa, and Tetracycline (ACSSuT) which was chromosomally integrated. Since then, the MDR ACSSuT backbone has also emerged on a plasmid and can be found in other serotypes. METHODS: Salmonella isolates from the animal arm of the National Antimicrobial Resistance Monitoring System (NARMS) were analyzed for the presence of MDR to ACSSuT. RESULTS: From 1997 through 2007, the ACSSuT phenotype was observed least often among isolates originating from chickens (is less than or equal to 4.3%), followed by turkeys (is less than or equal to 4.8%), swine (is less than or equal to10.9%) and cattle (is less than or equal to 20.4%). For Typhimurium isolates, over all years, ACSSuT occurred more often among isolates serotyped as Typhimurium var. 5- (30.9%) versus those serotyped as Typhimurium (18.5%). More Newport isolates (range 9.1% to 66.7%; 55.5% average) exhibited the ACSSuT phenotype than all other serotypes. However, the ACSSuT phenotype was also observed among the following serotypes: Agona, Bardo, Reading, Heidelberg, Dublin, and Uganda. Serotypes Agona and Dublin exhibited the highest percent ACSSuT phenotype in 2007 (45.2%; 19/42 isolates and 50%; 20/40 isolates, respectively). CONCLUSIONS: The MDR phenotype ACSSuT appears among Salmonella serotypes from all animal sources and is appearing with greater frequency among non-Typhimurium serotypes. These data demonstrate the need to determine both how and why this phenotype spreads among Salmonella serotypes.