Whole Genome Sequencing Revealed High Proportions Of ST152 MRSA Among Clinical Staphylococcus Aureus Isolates From Ten Hospitals In Ghana.

Abstract

Previous studies in Ghana indicated low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and predominance of ST152 methicillin-susceptible S. aureus (MSSA) among clinical isolates. ST152 MRSA clones are associated with severe infections and epidemics. Using whole genome sequencing (WGS), 159 S. aureus isolated from clinical sources (wound, blood, urine, ear, abscess, umbilical cord, eye, vaginal samples, and others) from 10 hospitals across Ghana were investigated. mecA (gene for methicillin resistance) was detected in 38% of the isolates. Panton–Valentine leucocidin toxin (PVL) gene occurred in 65% isolates, with 84% of the MRSA’s harboring the PVL gene. ST152 was the major clone, with 74% harboring the mecA gene. Other MRSA clones detected were ST5, ST5204, ST852, and ST1. MSSA clones included ST3249, ST152, ST5, ST1, and ST8. Twenty-three genes encoding resistance to 12 antimicrobial classes were observed with blaZ (97%) being the most prevalent. Other predominant resistance genes included tetK (46%), cat (42%), and dfrG (36%) encoding resistance for tetracyclines, phenicols, and diaminopyrimidine, respectively. Virulence genes for enterotoxins, biofilms, toxic-shock-syndrome toxins, hemolysins, and leukotoxins were also detected. Phylogenetic analysis revealed a shift in the dominant clone from MSSA ST152 to MRSA ST152 over the past decade. The study provides valuable insights into the genomic content of S. aureus from clinical sources in Ghana. The finding of ST152 MRSA in high numbers suggests a shifting epidemiological landscape of these pathogens and continuous surveillance using robust tools like WGS is needed to monitor the rise and spread of these epidemic clones in the country.