A Systematic Review and Meta-Analysis of the Bacterial Prevalences and Resistance Profiles in Selected Food-Producing Animals and Animal-Derived Products in Nigeria (2000–2025)

Abstract

Bacterial pathogens such as Escherichia coli and Salmonella spp. are widely reported in food-producing animals in Nigeria and contribute to animal disease, food contamination, and public health risk. However, evidence on their prevalence and antimicrobial resistance (AMR) patterns remains fragmented. This study systematically reviewed and meta-analyzed studies published between January 2000 and March 2025 on bacterial prevalence and resistance profiles in food-producing animals and related products in Nigeria. Data on pathogen type, host species, sample source, and antimicrobial susceptibility were extracted. Pooled prevalence estimates were calculated using random-effects meta-analysis (REML), and heterogeneity was assessed using Cochran’s Q and I² statistics. Thirty-two studies met the inclusion criteria. E. coli and Salmonella spp. were the most frequently reported pathogens and exhibited substantial multidrug resistance (resistance to ≥3 antimicrobial classes), particularly to tetracyclines, fluoroquinolones, sulphonamides, and β -lactams. The pooled prevalence of bacterial detection was 25% (95% CI: 14%–41%), with high heterogeneity ( I² = 96.9%). Higher prevalence was observed in poultry systems, and meta-regression indicated that sample size significantly influenced prevalence estimates. These findings highlight a substantial burden of resistant bacteria in food-animal systems and underscore the need for strengthened antimicrobial stewardship, improved surveillance, and coordinated One Health interventions in Nigeria.