Epidemiology, Pathogenicity, Animal Infections, Antibiotic Resistance, Public Health Significance, and Economic Impact of Staphylococcus Aureus: A Comprehensive Review

Staphylococcus aureus (S. aureus) is a gram-positive bacterium that has a greater impact on animal and human health by causing various diseases. S. aureus is present as normal flora of the skin and mucous membranes of both humans and animals but can cause disease when it gets the chance to invade either due to trauma or because of impaired immune responses of the host. Different virulence factors are involved in the mechanisms of pathogenesis of S. aureus which include surface proteins, enzymes, toxins, and others. These virulence factors play an important role in invasion, colonization, and survival of S. aureus in the host to cause staphylococcal diseases. Infections of S. aureus pose a major public health threat owing to its ability to cause mild to severe/life-threatening human diseases. Methicillin-resistant S. aureus (MRSA) has become a pathogen of increasing importance in hospitals (nosocomial infection) and the community. It can be mainly transmitted to humans by the consumption of food of animal origin. Foods associated with outbreaks of staphylococcal food poisoning include meat and meat products, poultry, and egg products, milk and dairy products, salads, cream-filled bakery products, and sandwich fillings. Additionally, it has great economic importance as it causes different diseases in animals. MRSA shows resistance to different antibiotics including penicillin, methicillin, vancomycin, and others owing to the presence of different antibiotic resistance genes and other resistance mechanisms.