Salmonella Carriage in Peripheral Lymph Nodes and Feces of Cattle at Slaughter Is Affected by Cattle Type, Region, and Season

Salmonella is a significant food safety concern in commercial beef production, and some contamination thought to occur by inclusion of -infected peripheral lymph nodes (LN) ground through fecal contamination. Surveillance processing plants assists packers risk management understanding seasonal trends risks associated with different cattle types. Approximately 25 samples 20 LN were collected from animals representing each five types (cull cattle, cull dairy cows, conventional feedlot all-natural raised without pharmaceuticals, grass-finished cattle) climate regions (mixed-temperatures dry, mixed-temperatures humid, hot cold) during three seasons (summer, fall, winter) better characterize inputs into facility. In total, 1,840 1,550 collected. Fecal cultured for , select isolates serogrouped screened antimicrobial resistance. Conventional had the highest concentrations (1.17 log10 CFU/g LN) this data set, while cows (1.96 feces). greatest prevalence both (32 18%, respectively) feces (37 49%, respectively), lowest (3%) (7%). As expected, concentration was all winter compared warmer seasons. When examined region, greater observed region 4 (hot-dry), than other regions. Only 21 50 susceptibility identified as multidrug resistant (MDR); responsible 48% MDR isolates, 38%, feedlot, grass-fed, 4.8%. These results indicate that production schemes, season, may influence which are most likely introduce abattoir, allowing awareness slaughter process.