The dominance of SCCmec type v genes among clinical isolates of methicillin-resistant Staphylococcus aureus from selected hospitals in Akwa Ibom State

Abstract

The occurrence of methicillin-resistant S. aureus (MRSA) and staphylococcal cassette chromosome mec (SCCmec) types has been reported in different geographical regions worldwide. The SCCmec gene is community-acquired and has been implicated in different types of infections and antimicrobial resistance, constituting potential public health threat. The occurrence of multidrug-resistant MRSA strains and SCCmec genes in clinical isolates of patients in secondary and tertiary health facilities in Akwa Ibom State were investigated in this study. This descriptive cross-sectional study was conducted among 300 in- and outpatients of all ages suspected with urinary tract infections, wound and ear infections at the University of Uyo Teaching Hospital, Uyo and General Hospital, Ikot Abasi. Bacterial isolation, identification, and antibiotic susceptibility testing were conducted using standard methods. Molecular detection of mecA and SCCmec subtype genes as well as sequencing and phylogenetic analysis were done according to standard protocols. Out of 30 MRSA strains detected, 26 (86.7%) exhibited multi-drug resistance and 23 (76.7%) possessed mecA gene and 28 (93.3%) harboured SCCmec type V genes. All the mecA-possessed strains also possessed the SCCmec type V gene, indicating they are predominantly community-acquired (CA-MRSA) strains. Eleven (73.3%) and 3 (20%) of the 15 selected MRSA strains phylogenetically analyzed showed evolutionary relatedness to S. aureus and S. haemolyticus, respectively. Co-acquisition of SSCmec V and mecA genes was detected in 5 (33.3%) of the MRSA strains. This study revealed the dominance of SSCmec V genes in methicillin-resistant Staphylococcus aureus isolates in the two health facilities and the need to institute effective antimicrobial stewardship to mitigate MRSA spread in Akwa Ibom State.