Whole Genome Sequencing and Comparative Genomics Analysis of a Pakistani Methicillin Resistant Staphylococcus Aureus

Abstract

Methicillin-resistant Staphylococcus aureus is a major cause of health-care associated infections. There is a growing concern of community-acquired MRSA strains worldwide that are responsible for skin and soft tissue infection. One such emerging clone of CA-MRSA is ST772, which is MRSA SCCmec type-V and is globally disseminated strain. During past decades, rates of MRSA infections have increased rapidly among the general population of Pakistan. To track and characterize MRSA strains in Pakistan, we collected an isolate LrCW from Combined Military Hospital (CMH) Lahore, Pakistan in March 2018. The isolate was found resistant against 13 different antibiotics including, Ampicillin, Methicillin, Oxacillin, Gentamycin, Meropenem, Erythromycin, Linezolid, Cefixime, Cefepime, Colistin Sulphate, Trimethoprim, Ciprofloxacin. Whole genome sequencing was employed for the isolate due to the high resistant profile using Illumina NGS technology. It produced a total of 241,931 bp reads and genome assembly produced 30 contigs with the total genome size of 274,0823 bp with 32.68% GC contents. Genome analysis revealed that MRSA strain LrCW belongs to ST772 and carrying SCCmec type-V. The genome was also found to have mobile genetic elements including plasmid, prophage and pathogenicity islands. These mobile genetic elements were found to have a number of genes associated with resistance and virulence that contributed to the emergence of MDR, and highly virulent strain of CA-MRSA in Pakistan