Characterization of antimicrobial susceptibility and virulence genes of Salmonella serovars collected at a commercial turkey processing plant.
OBJECTIVE
To determine the antimicrobial susceptibility profiles, distribution of class 1 integrons, virulence genes and genes encoding resistance to tetracycline (tetA, tetC, tetD and tetE) and streptomycin (strA, strB and aadA1) in Salmonella recovered from turkeys.


RESULTS
The antimicrobial susceptibility of 80 isolates was determined using National Antimicrobial Resistance Monitoring System. The distribution of resistance genes, class 1 integrons and virulence genes was determined using PCR. Resistances to tetracycline (76 x 3%) and streptomycin (40%) were common. Sixty-two (77 x 5%) isolates displayed resistance against one or more antimicrobials and 33 were multi-drug resistant. tetA was detected in 72 x 5% of the isolates, while tetC, tetD and tetE were not detected. The strA and strB genes were detected in 73 x 8% of the isolates. Two isolates possessed class 1 integrons of 1 kb in size, containing the aadA1 gene conferring resistance to streptomycin and spectinomycin. Fourteen of the virulence genes were detected in over 80% of the isolates.


CONCLUSIONS
This study shows that continuous use of tetracycline and streptomycin in poultry production selects for resistant strains. The Salmonella isolates recovered possess significant ability to cause human illness.


CONCLUSIONS
Information from this study can be employed in guiding future strategies for the use of antimicrobials in poultry production.
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Department of Veterinary and Microbiological Sciences, The Great Plains Institute of Food Safety, North Dakota State University, Fargo, ND 58105, USA.
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D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000382:microbiology*; D006801:Humans; D008462:Meat-Packing Industry; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D012475:Salmonella / Q000187:drug effects / Q000235:genetics* / Q000276:immunology; D012480:Salmonella Infections / Q000382:microbiology*; D012703:Serotyping; D000198:Spectinomycin / Q000494:pharmacology; D013307:Streptomycin / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology; D014422:Turkeys / Q000382:microbiology*; D014774:Virulence / Q000235:genetics
D000890:Anti-Infective Agents; D000198:Spectinomycin; D013752:Tetracycline; D013307:Streptomycin