Antibiotic resistance profile and genomic characterization of Staphylococcus aureus isolates from filarial lymphedema patients in Ghana

Abstract

Lymphatic filariasis (LF) is a neglected tropical disease that can be exacerbated by secondary bacterial infections that exhibit AMR. Antimicrobial resistance (AMR) is a pressing global health challenge, particularly in resource-limited settings. A bacterial epidemiological study of LF patients identified Staphylococcus aureus as a prevalent Gram-positive pathogen associated with the disease. The emergence of AMR in S. aureus strains poses a significant threat to patient outcomes and public health. By analysing genetic determinants of resistance, we can inform the development of targeted interventions to mitigate the impact of AMR in LF and related conditions. This study comprehensively characterizes the genetic determinants of AMR in six S. aureus isolates obtained from chronic wounds of LF patients in Southern Ghana. Combining antibiotic susceptibility testing (AST) with whole-genome sequencing (WGS), the AST reveals 100 % (6/6) of isolates were resistant to one or more antibiotic(s), and 33.3% (2/6) were multi-drug resistant (MDR). Resistance phenotypes were largely explained by antibiotic resistance genes in WGS data. All isolates were methicillin-resistant, with 33.3% showing multidrug resistance; ST1 was the predominant sequence type (50%). Furthermore, the identified plasmids include rep5a (18.2 %), rep7a (22.7 %), rep7c (13.6 %), rep16 (18.2 %), rep20 (13.6 %), rep21 (4.5 %), rep 22 (4.5 %), and repUS43 (4.5 %). Additionally, genes encoding for fibrin production (fnbA/B, sdrC/E, and vWbp), cell adhesion proteins (can, cap8A/B/F/M, clfA/B, ebp, and icaA/B), type VII secretion system proteins (coa, esaA, essA, esxA, and isdA/G), and toxin-producing enterotoxins (coa, hlgA/B/C, scn, sea/c/d/h, and sel/k/l) were found in the isolates. In conclusion, this emphasizes the urgent need for vigilant surveillance, optimized therapeutic protocols, and strengthened public health interventions such as infection prevention measures to effectively mitigate the impact on public health.