Genomic Patterns of Methicillin-Resistant Staphylococcus Aureus Isolates obtained from Patients seeking Treatment in Nakuru County Referral and Teaching Hospital, Kenya

Abstract

Background: Staphylococcus aureus is a bacterial pathogen and the global cause of both community and hospital acquired infections, posing a serious threat of antimicrobial resistance. Methicillin-Resistant Staphylococcus aureus is a global health concern that is associated with significant morbidity and mortality. This study was done to find out the molecular characterization of staphylococcus aureus. MRSA lineages and strains was identified using various typing methods, such as), multilocus sequence typing (MLST), SCCmec typing, Centre of Genomic Epidemiology (CGE), PUBMLTS and spa typing. Objective: To determine the genotypic patterns of MRSA isolates obtained from patients seeking treatment in Nakuru County Referral and Teaching Hospital. Study design: A descriptive cross-section study with a laboratory experimental component. Setting: It was carried out in Nakuru County Referral and Teaching Hospital which is based in Nakuru County. This Hospital serves residents of Nakuru County and its neighboring Counties. Subject: A total of 25 staphylococcus aureus isolates underwent Whole genome sequencing for molecular characterization. Results: A significant proportion of MRSA isolates showed high resistance to multiple antibiotics, including penicillin G, erythromycin, clindamycin, ciprofloxacin, and gentamycin. Molecular analysis revealed a diverse range of clonal complexes and strain types, with CC8 and ST152 being predominant. A variety of resistance genes were detected, with mecA being the most common methicillin resistance gene. High prevalence of virulence genes, including aur, hlgA, hlgB, and icaC, was also observed. Multiple plasmid replicons were identified, indicating their role in spreading resistance and virulence factors among MRSA strains. Conclusion: This study provided comprehensive insights into the resistance patterns, and molecular characteristics of staphylococcus aureus isolates at Nakuru County Referral and Teaching Hospital. The high antibiotic resistance observed underscores the urgent need for effective antimicrobial stewardship. The molecular diversity and high prevalence of resistance and virulence genes highlight the complex nature of MRSA infections, necessitating continuous surveillance, stringent infection control measures, and the development of new antimicrobial agents to manage the rising threat of MRSA and improve patient outcomes.