Abstract

Staphylococcus aureus (S. aureus) continues to constitute a global health threat, exacerbated by the rapid emergence of multidrug resistance, enhanced by various genetic mechanisms. This review aims to highlight the genetic diversity, mechanisms, and prevalence of major antibiotic resistance genes in S. aureus detected across studies in Nigeria based on molecular findings. The major antibiotic resistance genes detected were mecA, blaZ, erm, tet, cat, lnuA, femA, aacA-aphD, vanA, and vanB. The mecA gene was the most frequently identified and is responsible for methicillin resistance. Also, mecC, a homolog of mecA was detected in some studies. Co-existence of mecA and blaZ, which encodes β-lactamase, was also identified. Resistance to macrolides and tetracycline antibiotics was mediated by erm and tet genes, while cat and aacA-aphD were associated with resistance to chloramphenicol and aminoglycosides, respectively. The detection of vancomycin-resistant genes (vanA and vanB) points to the disturbing emergence of vancomycin-resistant S. aureus isolates in Nigeria. The widespread presence of antibiotic resistance genes poses significant health risks to humans, especially in hospitals and community environments, and could further contaminate ecological systems through wastewater and agricultural runoff. In conclusion, the presence and distribution of multiple antibiotic resistance genes in S. aureus isolates in Nigeria underscore the urgent need to strengthen antibiotic surveillance and implement integrated public health interventions to control antibiotic resistance transmission across clinical, veterinary, and environmental domains.

Key words: antibiotic resistance, antibiotic resistance genes, blaZ, Nigeria, mecA, S. aureus