Antimicrobial Resistance in Pig Farming: Prevalence, Transmission Dynamics, Genetic Determinants, and Policy Implication in Tanzania

Antimicrobial resistance (AMR) poses a critical global health threat, impacting human, animal, and environmental health. Pigs act as significant reservoirs for multidrug-resistant (MDR) pathogens; however, there is limited data regarding their role in AMR transmission in Tanzania. This study synthesizes existing data on the prevalence, resistance profiles, and genetic determinants of MDR pathogens in pigs, assesses transmission pathways and evaluates Tanzania’s AMR policies in comparison to regional and global strategies. A systematic review of peer-reviewed literature, government reports, and case studies focuses on MDR bacteria, including Escherichia coli, Salmonella spp., Campylobacter spp., Enterococcus spp., and methicillin-resistant Staphylococcus aureus (MRSA). E. coli demonstrated a prevalence of up to 73.1% and 51.6% multidrug resistance, while Salmonella spp. and Campylobacter spp. exhibited notable resistance to tetracyclines, beta-lactams, and quinolones. Key resistance genes, such as blaCTX-M, tetM, ermB, mecA, and vanA, were identified, highlighting the potential for horizontal gene transfer and zoonotic transmission. Major AMR transmission routes include direct contact, foodborne exposure, and environmental contamination. Tanzania’s AMR surveillance in pig farming is limited, with weak enforcement of antibiotic regulations and the absence of a coordinated national monitoring system. Comparative policy analysis reveals significant gaps, calling for stricter antibiotic control, improved AMR monitoring, and public education. A One Health approach is crucial, integrating veterinary, public health, and environmental interventions. Strengthening regional collaboration and aligning Tanzania’s AMR policies with global standards is essential to effectively combat the growing AMR threat.