Whole genome sequencing-based prediction of antibiotic-resistance of ocular Staphylococcus aureus across six continents

Abstract

Staphylococcus aureus is a leading cause of ocular infections, resulting in vision loss in severe cases. Understanding the antibiotic resistance profiles of ocular S. aureus can help customize treatments. However, there is a lack of global data on the resistance patterns of ocular isolates and comparative regional analyses. Hence, WGS data from 195 ocular S. aureus isolates across six continents were analysed to identify antibiotic resistance genes (ARGs) and predict antibiotic resistance phenotypes in this study. A total of 40 ARGs were detected, involving resistance mechanisms against aminoglycosides, beta-lactams, macrolide-lacosamide-streptogramin B (MLS_B), glycopeptides, tetracyclines, other antibiotic classes, and efflux pump regulators. Notably, the prevalences of ARGs associated with efflux pump regulators and beta-lactams were particularly high (>80 %). Resistance to 45 antibiotics was predicted across the isolates, with 51 % identified as multidrug-resistant (MDR), while only 8 % were predicted to be fully susceptible to all predicted antibiotics. Regional data varied, with isolates from North America and Asia exhibiting the most extensive resistance patterns, showing predicted resistance to 45 and 41 antibiotics, respectively. In contrast, Oceanian isolates were predicted to be resistant to only 14 antibiotics. Beta-lactams showed the highest predicted resistance prevalence among all antibiotic classes. Notably, North American isolates showed markedly higher resistance to MLS_B antibiotics. A high proportion of cloud genes highlights the need for monitoring regional resistance. This study provides antibiotic resistance profiles among ocular S. aureus using WGS prediction, emphasizing the importance of regional surveillance and antimicrobial stewardship to suggest effective treatment strategies. It is recommended that WGS of more strains be deposited to overcome limited data, and laboratory tests be performed to analyse the consistency between genetic predicted and phenotypic resistance.