|Thomas, L - USDA, FSIS, NVSL|
Submitted to: United States Animal Health Association Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 4, 1995
Publication Date: N/A
Technical Abstract: Two culture media were compared for the isolation of Salmonella spp. from bovine and swine feces. Two preenrichment media were also compared for the reisolation of Salmonella spp. from swine feeds which had been stored at 4 deg C. One g of feces was placed into Tetrathionate broth (Tet) and GN Hajna broth (GN). Following incubation, 100 ul was transferred into Rappaport-Vassiliadis R-10 medium (Tet-R and GN-R). Cultures were struck to brilliant green agar with sulfadiazine (BGS), or for the swine feces to BGS, xylose-lysine-Tergitol 4 (XLT4) and brilliant green agar with novobiocin (BGN). Feed samples were pre-enriched in buffered peptone water (BPW) or Universal Preenrichment Broth (UPEB) prior to culture as described for the feces. Presumptive positive colonies were confirmed by biochemical analysis, serogrouped, the sent to the National Veterinary Services Laboratories for serotyping. From 273 positive bovine fecal samples, 77.3% %were recovered following culture in Tet-R while only 49.8% and 36.6% were recovered in Tet alone or GN-R, respectively. Salmonella spp. were most often recovered from swine fecal samples cultured in Tet-R (93%). Culture in GN-R was least sensitive. For both studies identification of positive herds was best achieved by culture in Tet-R. Additionally, culture in Tet- R identified all positive samples within a herd. No differences between plating media (BGS, BGN, and XLT4) were observed. Only 5 samples were positive from the stored feed preenriched in BPW. Only 3 samples were positive in UPEB and 2/5 matched recovery in BPW. These data demonstrate that Salmonella spp. has a higher probability of being recovered following use of both Tet and Rappaport R-10 media than any other medium. Additional studies need to be conducted using BPW and UPEB.