Identification of Toxic Shock Syndrome Toxin-1 (TSST-1) gene in Staphylococcus aureus isolated from bovine mastitis milk

Abstract

Staphylococcus aureus is a major causative pathogen of clinical and subclinical mastitis of dairy domestic <br />ruminants. This agent produces a variety of extracellular toxins and virulence factors including Toxic Shock <br />Syndrome Toxin-1 (TSST-1) which is the major cause of Toxic Shock Syndrome (TSS). In this study 58 <br />S. aureus isolates obtained from 9 dairy herds in East and West Azerbaijan provinces of Iran. The tested <br />isolates were identified on the basis of the cultural and biochemical properties as well as by amplification of <br />the aroA gene, specific to S. aureus. Isolates were also analyzed for the presence of the TSST-1 encoding <br />gene (tst) using Polymerase Chain Reaction (PCR). tst gene 350 bp was detected in 9 (15.5%) of the total <br />number of 58 isolates. The present study revealed that the PCR amplification of the aroA gene could be <br />used as a powerful tool for identification of S. aureus from the cases of bovine mastitis. Results also showed <br />that the strain of S. aureus which caused mastitis can potentially produce staphylococcal toxic shock <br />syndrome toxin-1. Overall, our results suggest that it is of special importance to follow the presence of <br />TSST-1 producing S. aureus in foodstuffs, especially for protecting the consumers from toxic shock <br />syndrome.