Whole-genome sequence analysis of multidrug-resistant Staphylococcus epidermidis ST35 strain isolated from human ear infection of an Iraqi patient

Abstract

Objectives: Staphylococcus epidermidis is the most common coagulase-negative Staphylococcus colonising the human skin and mucous membranes and is a major cause of nosocomial infections. Antimicrobial resistance (AMR) in S. epidermidis has increased significantly in the last few decades, threatening human health globally. Methods: This study explored the AMR status in an S. epidermidis isolate (AK-612) from an ear infection of an Iraqi student who had undergone treatment for the same. Whole-genome sequence analysis was also performed. Results: Strain AK-612 is a methicillin-resistant S. epidermidis (MRSE) isolate possessing an SCCmec type V element. Strain AK-612 belongs to sequence type 35 (ST35), clonal complex 2 (CC2), which to the best of our knowledge has not been reported previously in Iraq, having been previously reported only in Portugal and Germany. In Portugal, S. epidermidis ST35 was reported to colonise the nasal area of a bird of prey (Buteo buteo) that undergoes a migratory period extending its range from Europe to Asia. The plasmid of S. epidermidis AK-612 showed greatest identity with plasmid 1 of S. epidermidis strain PM221, which was isolated in Finland from an intramammary bovine infection. This ST35 strain may have crossed continental boundaries and expanded its occurrence in animals and humans. Conclusion: This is a matter of serious concern as the dissemination of multidrug-resistant S. epidermidis in human infections is a major hindrance for the treatment of these infections. Transmission of this isolate across continental boundaries will make infection control a difficult task.

Keywords

• Antimicrobial resistance
• Bacteria
• Whole-genome sequencing
• Staphylococcus epidermidis