Molecular detection of Alpha toxin in local Staphylococcus aureus isolates

Abstract

Bacterial toxins are the most important virulence factors that could hurt humans causing serious health problems. Staphylococcus aureus have a wide range of extracellular toxins; one of them is alpha toxin; haemolysin that degrade red blood cells. Thirty S. aureus isolates were isolated from clinical and animal-origin foods sample. Staphylococcus aureus isolates were chosen for the phenotypic and genotypic detection of alpha toxin. Bacterial deoxy ribonucleic acid was extracted and specific primers were designated for this study. Polymerase chain reaction was depended to detect the prevalence of haemolysin coding gene in local isolates in Iraq. On the other hand, silver nanoparticles were biosynthesized using food origin bacterial isolate of Salmonella. The biosynthesis was done in optimized conditions, purified, and tested for their antimicrobial activity. Phenotypic detection methods revealed the ability of 70% to produce alpha toxin. Whereas the genetic tool was very precise in detecting the genetic content (93.33%) of alpha toxin gene in clinical and animal-origin foods. The biosynthesized nanoparticles were with an average diameter of 44.89 nm. They have an antimicrobial activity against haemolysin producing S. aureus isolates. Monitoring and understanding the hemolysin production by S. aureus strains in food samples can aid in implementing effective food safety measures to prevent contamination and ensure the safety of food products.