Diverse Staphylococcus aureus lineages in a tertiary hospital in North Central Nigeria: emergence of CC1-ST772-MRSA, CC8-ST789-MRSA, and ST152-MRSA

Introduction Staphylococcus aureus is a human pathogen associated with both hospital- and community-acquired infections. Data on its molecular epidemiology in North Central Nigeria are currently unavailable. This study investigated the antibiotic resistance, virulence genes, and the population structure of S. aureus in a tertiary hospital in North Central Nigeria. Methods S. aureus strains from various clinical specimens collected between July 2017 and July 2021 were characterized based on antibiotic susceptibility testing and PCR detection of nuc , mecA , PVL ( lukS -PV/ lukF -PV), and immune evasion ( scn , sak , chp ) genes. Genotyping of the strains was performed by spa typing and whole-genome sequencing (WGS) of representative strains. Results Of the 169 S. aureus strains, 52% ( n = 88) were recovered from wound infections. The resistance rates were highest for penicillin ( n = 162; 96%), followed by trimethoprim-sulfamethoxazole ( n = 128; 76%), tetracycline ( n = 66; 39%), gentamicin ( n = 54; 32%), ciprofloxacin ( n = 53; 31%), erythromycin ( n = 31; 18%), and clindamycin ( n = 3; 2%). Overall, 90 (53%) were mecA -positive (MRSA), and 81 strains (48%) were multidrug-resistant (MDR). Genotyping revealed a diverse S. aureus population, comprising 37 spa types and 19 sequence types (STs) in nine clonal complexes (CC1, CC5, CC8, CC15, CC22, CC30, CC45, CC88, CC121) and two singletons (ST152 and ST7572). The predominant MRSA lineages comprised CC1-ST772-MRSA-V-t657, CC8-ST789-MRSA-V-t091, and ST152-MRSA-Vc-t4690, while the common methicillin-susceptible S. aureus (MSSA) lineages were ST152-MSSA-t355, CC15-ST15-MSSA-t084, and CC5-ST5-MSSA-t311. The dfrG gene was detected across lineages, and 65% of all strains (MSSA: 68%; MRSA: 62%) were PVL-positive. Phylogenetic analysis revealed strain diversity, suggesting the dissemination of different lineages across various wards within the hospital. Conclusion The S. aureus population at a tertiary hospital in North-Central Nigeria is highly diverse. The detection of PVL-positive ST152-MRSA-Vc and MDR CC1-ST722-MRSA-V is of significant public health concern. Genomic surveillance of S. aureus , combined with clinical data, is essential for effective infection prevention and control strategies.