Impacts of zootechnical factors on Salmonella contamination in swab samples using real-time PCR at the Yaounde slaughterhouse

Abstract

• Salmonella detected in 14.9% of 705 samples at the Yaounde abattoir using real-time PCR. • Highest contamination occurred in processed carcasses (17.73%). • Zootechnical factors showed no significant effect on contamination • Multivariate analysis confirmed the multifactorial nature of Salmonella contamination • Carcass sample categories significantly influenced Salmonella detection. • Poor slaughterhouse hygiene identified as main contamination pathway. • Real-time PCR is a valuable tool for early Salmonella surveillance. Salmonella contamination of beef carcasses remains a major public health concern, particularly in low- and middle-income countries where abattoir hygiene and traceability systems are often inadequate. This study aimed to generate context-specific data on Salmonella contamination along the cattle slaughter chain at the Yaoundé abattoir using real-time PCR, and to evaluate the influence of zootechnical factors of slaughtered cattle within a One Health framework. A total of 705 swab samples were collected from live cattle (n = 145), carcasses (n = 310), butchers’ hands (n = 145), and meat contact surfaces (n = 105). Salmonella detection was performed using TaqMan probe-based real-time PCR. Overall, 14.9% (95% CI: 12.4%–17.6%) of samples were positive for Salmonella , with prevalence rates of 5.20% (95% CI: 2.4%–10.6%) in live cattle, 17.73% (95% CI: 13.89%–22.38%) in carcasses, 1.9% (95% CI: 0.52% – 6.68%) in contact surfaces, and 5.52% (95% CI: 2.8% – 10.5%) in butchers’ hand swabs. Salmonella occurrence differed significantly among sample categories (p < 0.05). However, multivariate logistic regression revealed that none of the assessed zootechnical factors (sex, age, breed, transport, origin, cleanliness, body condition, and production system) were independently associated with contamination (p > 0.05). These findings suggest that Salmonella contamination in slaughtered cattle is driven by systemic hygiene and biosecurity shortcomings rather than individual animal-related factors. Overall, the moderate prevalence observed reflects gaps in slaughter hygiene and biosecurity. Strengthening sanitation practices, enforcing Hazard Analysis and Critical Control Point (HACCP) measures, and adopting molecular surveillance tools such as real-time PCR are essential to reduce contamination risks and protect public health.