Whole Genome Sequencing and Antimicrobial Resistance of Staphylococcus aureus from Surgical Site Infections in Ghana

Abstract

<i>Staphylococcus aureus</i> (<i>S. aureus)</i> is a common cause of surgical site infections (SSIs) globally. Data on the occurrence of methicillin-susceptible <i>S. aureus</i> (MSSA) as well as methicillin-resistant <i>S. aureus</i> (MRSA) among patients with surgical site infections (SSIs) in sub-Saharan African are scarce. We characterized <i>S. aureus</i> from SSIs in Ghana using molecular methods and antimicrobial susceptibility testing (AST). Wound swabs or aspirate samples were collected from subjects with SSIs. <i>S. aureus</i> was identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS); AST was performed by Kirby-Bauer disk diffusion, and results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guideline. Detection of <i>spa, mecA</i>, and <i>pvl</i> genes was performed by polymerase chain reaction (PCR). Whole-genome sequencing (WGS) was done using the Illumina MiSeq platform. Samples were collected from 112 subjects, with 13 <i>S. aureus</i> isolates recovered. Of these, 92% were sensitive to co-trimoxazole, 77% to clindamycin, and 54% to erythromycin. Multi-drug resistance was detected in 5 (38%) isolates. The four <i>mecA</i> gene-positive MRSA isolates detected belonged to ST152 (<i>n</i> = 3) and ST5 (<i>n</i> = 1). In total, 62% of the isolates were positive for the Panton-Valentine leukocidin (<i>pvl</i>) toxin gene. This study reports, for the first time, a <i>pvl</i>-positive ST152-t355 MRSA clone from SSIs in Ghana. The occurrence of multi-drug-resistant <i>S. aureus</i> epidemic clones suggests that continuous surveillance is required to monitor the spread and resistance trends of <i>S. aureus</i> in hospital settings in the country.