Prevalence of pvl and tsst 1 Virulence Genes in Staphylococcus aureus Clinical Isolates from Angré University Hospital in Abidjan, Côte d’Ivoire

Abstract

Background: Staphylococcus aureus ( S. aureus ) is a major cause of serious human infections and produces multiple virulence factors. In Côte d’Ivoire, local molecular data remain scarce. This study evaluated the prevalence of pvl and tsst 1 genes in clinical S. aureus isolates from Abidjan. Methods : Two hundred clinical isolates (100 MRSA: methicillin-resistant S. aureus ; 100 MSSA: methicillin-susceptible S. aureus ) were collected at Angré University Hospital (CHU Angré) between January 2022 and February 2024. Isolates were identified using phenotypic methods, the VITEK 2 system, and PCR confirmation targeting the nuc gene. The pvl and tsst 1 genes were detected using conventional PCR. Virulence profiles were compared according to hospital department, MRSA/MSSA profile, and clinical severity classification. Results : The pvl gene was detected in 72.0% of MRSA and 60.5% of MSSA isolates. A double-positive profile ( pvl + / tsst 1 + ) was found in 54.6% of the isolates, particularly in critical care units. No significant difference was observed between MRSA and MSSA for pvl (p = 0.344) or tsst 1 (p = 0.286). However, the presence of the pvl gene was strongly associated with clinical severity, with 90.09% of severe cases having the pvl gene (p = 0.0002). The tsst 1 gene was more frequently found in non-severe cases (54%) than in severe cases (35%), but the difference was not significant (p = 0.374). Conclusion : The high prevalence of pvl and tsst 1 genes, including in MRSA strains, highlights the circulation of highly virulent S. aureus lineages in Abidjan. These findings emphasize the need for enhanced molecular surveillance as part of an integrated strategy to control S. aureus infections.