Bacillus cereus in African food systems from 2000 to 2025 as an underrecognized foodborne pathogen and emerging public health challenge

Abstract

Foodborne diseases pose a major public health threat in Africa, driven by rapid urbanization, expanding informal food markets, and limited cold-chain infrastructure. Among bacterial pathogens, Bacillus cereus is a persistent but often overlooked hazard due to its spore-forming, toxin-producing capabilities. This mini-review synthesizes peer-reviewed studies published between January 2000 and October 2025 on the occurrence, toxin gene diversity, and antimicrobial resistance of B. cereus in African food systems. A structured literature search was conducted in PubMed, Scopus, Web of Science, Google Scholar, and regional databases. Only ten studies met eligibility criteria, revealing severe data scarcity across 54 African countries over 25 years. Reported contamination rates ranged from 15% to over 70%, depending on food type and detection method. Cereal-based foods, dairy products, and ready-to-eat street foods were most frequently contaminated. Toxin genes (nhe, hbl, cytK) were highly prevalent; the emetic toxin cluster (ces) was less common but present. Antimicrobial resistance to β-lactams was consistently reported. No pan-African surveillance system exists for B. cereus, and outbreaks are likely misclassified as unspecified food poisoning. Bacillus cereus should be considered an indicator of structural weaknesses in African food safety systems. Strengthening laboratory capacity (including PCR and whole-genome sequencing), integrating molecular tools into routine surveillance, and aligning with continental strategies (African Union Food Safety Strategy, One Health) are urgently needed.