Genetic Characterization of Staphylococcus aureus Isolates Associated with Toxic Shock Syndrome Toxin Production: An Epidemiological and Bioinformatics Approach

Abstract

Staphylococcus aureus is an opportunistic pathogen, a member of the ESKAPE group, associated with nosocomial infections and foodborne illnesses due to its production of various toxins. This study conducted a comprehensive genomic characterization of S. aureus isolates producing toxic shock syndrome toxin (TSST-1) using a comparative genomics and bioinformatics approach. A total of 166, including 3 bovine mastitis isolates and 163 public genomes, were analyzed. Twenty-eight distinct sequence types (STs) were identified, with ST30 and ST5 being the most prevalent, corresponding to the clonal complexes CC30 and CC5, respectively. Phylogenetic reconstruction revealed two major clades aligned with these complexes, each exhibiting unique virulence factor profiles. Notably, TSST-1 was detected in bovine mastitis genomes, alongside a broad repertoire of virulence markers, such as enterotoxins and secretion system components, posing a potential risk to public health. Additionally, genes related to environmental information processing systems, including ABC transporters and phosphotransferase systems, were prevalent. These results underscore the need for strengthened genomic surveillance and the implementation of both preventive and corrective measures in dairy herds to mitigate zoonotic transmission and ensure food safety.