Exploring a Possible Association Between Salmonella Contamination in Liver Abscesses, Lymph Nodes, and Carcasses of...

Salmonella is common in cattle without clinical signs, persisting in feces, peripheral lymph nodes, and occasionally liver abscesses. While the association with this pathogen has been studied extensively, knowledge gaps remain regarding its relationship with beef × dairy crossbred cattle. Given the high prevalence of liver abscesses in beef × dairy crosses and their potential link to gastrointestinal disruption and subsequent pathogen translocation, this study investigated Salmonella contamination in lymph nodes, liver abscesses, and carcasses of beef × dairy cross cattle. Lymph nodes (LNs; subiliac, superficial inguinal, mesenteric, and prescapular) and liver samples were collected from case (n = 124; liver abscess) and control (n = 124; no liver abscess) beef × dairy cross cattle carcasses. Samples were analyzed for Salmonella using the BAX®-System Real-Time Salmonella Assay, and isolates recovered from the original enrichment were serotyped. Prevalence ranged from 4.4% for livers to 8.5% for mesenteric LNs. Salmonella prevalence did not vary by sample type (P = 0.5574), carcass category (case vs. control; P = 0.4326), or sample type × carcass category (P = 0.4745). When analyzed on a carcass level (one or more LNs positive in a single carcass), prevalence did not vary (P = 0.3575), with 19.4% and 24.2% (not model-adjusted) in control and case carcasses, respectively. Salmonella Montevideo was the most frequently recovered serotype (19.1%), followed by Muenchen (10.0%) and Typhimurium (9.1%). Salmonella was detected across all sample types with no differences detected in prevalence by sample type or carcass category, and the presence of liver abscesses was not associated with an increased risk of Salmonella contamination of LNs. Although these data suggest that no relationship exists between Salmonella and liver abscesses in beef × dairy crossbred cattle, the findings are based on a limited sample size and should be validated in larger, more comprehensive studies.