ARS | Publication request: Antimicrobial resistance in Salmonella isolates recovered from swine: A NARMS report

Submitted to: Safepork
Publication Type: Proceedings
Publication Acceptance Date: March 9, 2007
Publication Date: May 9, 2007
Citation: Cray, P.J., Dargatz, D.A., Anandaraman, N., Wineland, N.E., Frye, J.G., Bailey, J.S. 2007. Antimicrobial resistance in Salmonella isolates recovered from swine: A NARMS report. Safepork. 7:510-513.

Technical Abstract: In 1996 the Food and Drug Administration Center for Veterinary Medicine established the National Antimicrobial Resistance Monitoring System – Enteric Bacteria (NARMS) as a post-approval monitoring program. From 1997 through 2005 10,565 Salmonella isolates originated from swine slaughter/processing (n=3,848), diagnostic (n=4,579) and on-farm (n=2138) sources as part of the animal arm of NARMS. Relative to 2005, the top five Salmonella serotypes from slaughter/processing (in decreasing frequency) were S. Derby, S. Typhimurium var. 5-, S. Infantis, S. Anatum, and S. Johannesburg while diagnostic serotypes were S. Typhimurium var. 5-, S. Choleraesuis var. kunzendorf, S. Derby, S. Typhimurium, and S. Heidelberg. Increased antimicrobial resistance was most often observed for diagnostic versus slaughter/processing isolates although there were exceptions for some drug and serotype combinations. For all years, > 55% of the slaughter/processing isolates were either pan-susceptible or resistant to only one antimicrobial, which was most often tetracycline. Since 1997, approximately 41% of the isolates exhibited multi-drug resistance, defined as resistance to is greater than or equal to antimicrobials. Of the 723 S. Typhimurium DT104 isolates from swine only 24% (n=176) originated from slaughter/processing. These data reaffirm that overall patterns of resistance are highly dependent on the Salmonella serotype distribution and is variable when measured at different points along the farm to fork continuum.