ARS | Publication request: SEROTYPES AND ANTIMICROBIAL RESISTANCE IN SALMONELLA ISOLATES FROM SWINE,NARMS-EB 1997-2000

Submitted to: International Symposium on the Epidemiology and Control of Foodborne Pathogens in Pork
Publication Type: Abstract Only
Publication Acceptance Date: June 2, 2001
Publication Date: September 2, 2001
Citation: Wray, C., Cray, P.J., Headrick, M., Gray, J.T., Dillard, L., Dargatz, D.A., Haro, J.H. 2001. Serotypes and antimicrobial resistance in salmonella isolates from swine,narms-eb 1997-2000. International Symposium on the Epidemiology and Control of Foodborne Pathogens in Pork. P. 375-376.

Technical Abstract: The National Antimicrobial Resistance Monitoring System (NARMS) was developed to monitor antimicrobial resistance development in enteric organisms. Resistance between swine isolates collected in 1997-2000 from federally inspected slaughter and processing plants (SI), and diagnostic laboratories were tested against 17 antimicrobial drugs using the Sensititre**TM system. From 1997-2000 (Note: 2000 data are preliminary) the most frequent serotype from SI was S. Derby. In 1997, resistance was observed to Tetracycline (Tet; 56%), Streptomycin (Str; 41%), Sulfamethoxazole (Sul; 73%) and Apramycin (Apr; 4%). From 1998-2000, percent resistance to TetStrSul was >/= 44% in each year; however , in addition to Apr**R, resistance was also observed to Ampicillin (Amp), Chloramphenicol (Chl), Gentamicin (Gen), and Kanamycin (Kan) in 1998, Amikacin (Ami), Amox.Clavulanic Acid (AM/Cl), and Ceftiofur (Cefti) in 1999 and to Cephalothin (Cep) in 2000. No resistance to Apr**R, was observed in 2000. For 1997-2000, the second most common serotype among SI was Typhimurium followed by Heidelberg in 1997 and Johannesburg for 1998- 2000. Conversely, for diagnostic isolates (DI), the top serotype from 1997-2000 was typhimurium followed by Derby in 1997-98 and S. choleraesuis in 1999-2000. The third most common serotypes were S.mbandaka, Heidelberg, Derby and Heidelberg for 1997-2000, respectively. Regardless of serotype, resistance was higher among the DI as compared to SI. Additionally, multiple resistance was more likely to occur among DI verses SI. Higher levels of resistance were found in diagnostic isolates. Further characterization of the isolates may identify common serotypes that persist through to slaughter and processing.