Isolation and antimicrobial profiling of Salmonella in apparently healthy slaughtered cattle and abattoir personnel at Debre Birhan municipal abattoir, Ethiopia

Foodborne diseases caused by Salmonella remain a major public health concern, often linked to contaminated animal products. Asymptomatic cattle can transmit the pathogen during slaughter and meat handling, while rising antimicrobial resistance further complicates treatment. However, limited data in Debre Birhan hinder effective control measures. Therefore, a cross-sectional study was conducted at the Debre Birhan municipal abattoir from October 2024 to January 2025 to estimate the prevalence of Salmonella in apparently healthy slaughtered cattle and abattoir personnel, assess associated risk factors, and determine antimicrobial resistance patterns of the isolates.

A total of 452 samples were collected, with equal representation (25% (113/452) each) from cecal contents, knife swabs, carcass swabs, and hand swabs, and examined for Salmonella following standard procedures recommended by the International Organization for Standardization. Additionally, semi-structured questionnaires were administered to abattoir workers to assess personal hygiene practices.

Out of the 452 samples examined, 29 (6.42%; 95% CI: 4.34–9.09) were culture-positive for Salmonella, with the highest proportion from carcass swabs (12/113; 10.62%; 95% CI: 5.61–17.82), followed by cecal contents (9/113; 7.96%; 95% CI: 3.70–14.58), knife swabs (6/113; 5.31%; 95% CI: 1.97–11.20), and hand swabs (2/113; 1.77%; 95% CI: 0.22–6.25). There was a statistically significant association between Salmonella detection in cecal contents and carcass contamination at the individual cattle level. Cattle carrying Salmonella in their cecal contents were observed to have higher odds of contaminated carcasses compared with non-carrier animals (OR = 4.8; 95% CI: 1.01–22.75). However, this relationship should be interpreted as an association between samples collected from the same animal rather than as evidence of an independent risk factor. All isolates were tested for susceptibility to a panel of 13 selected antimicrobials, and most showed resistance to one or more agents. Multidrug resistance (MDR) was observed in the majority of resistant isolates. The highest resistance rates were recorded for ampicillin (100%), followed by ceftazidime (93.1%) and azithromycin (93.1%).

The findings indicate the presence of Salmonella contamination in slaughtered cattle and abattoir environments, with a high level of multidrug resistance among isolates. This highlights the need for improved hygienic practices in abattoirs and prudent use of antimicrobials to reduce public health risks.