Whole Genome Molecular Characterization of Methicillin Resistant Staphylococcus aureus Isolated From Clinical Settings in Lebanon

Abstract

The high prevalence of multi-drug resistant Staphylococcus aureus, particularly the Methicillin-Resistant S. aureus (MRSA), has become a worldwide health concern. In this study, we used whole-genome sequencing, multi-locus Sequence Typing (MLST), S. aureus protein A (spa), and Staphylococcal Chromosomal Cassette (SCCmec) typing of MRSA and pan-genome analysis to study the molecular characteristics, resistance patterns, and relatedness of the isolates. In silico typing was used to determine the antimicrobial resistance and virulence determinants, rep families, and prophages. All the studied isolates carried the blaZ gene, and most were multi-drug resistant. Two MRSA isolates recovered from hospitalized patients were additionally resistant to vancomycin. Seven distinct MLST allelic profiles were identified, and the most common STs and spa types, respectively, were ST789 and ST1and t091 and t127. SCCmec typing of MRSA revealed the prevalence of type V(5C2). MRSA ST789-t091-V was the predominant type, but we also detected SCCmec cassette harboring ccrA1B1 and mecC2, classified as SCCmec type IX(1C2).