Question

Why is S. aureus such a virulent organism? What conditions can it cause? What about the organism can lead to so many different kinds of infection/disease?

Answer 1

Staphylococcus are gram positive bacteria which appear a cluster of grapes under the gram staining which are cocci shaped hence named staphylococcus. The organism are present on the skin, nasal passages as normal flora of body but under favorable conditions these organism can cause disease ranging from minor infection like skin infection to life threatening disease like pneumonia, osteomyelitis and endocarditis. They cause skin infection like pimples, impetigo, furuncles, cellulitis and abscesses. Some organism also produces toxins called as exotoxins leading toxic shock syndrome. Some organism produces endotoxin which can cause food poisoning.

1. Gastrointestinal: Staphylococcus aureus causes acute episodes of food poisoning via preformed enterotoxins. Food items likely to be infected by staphylococcal food poisoning include meat and meat products; poultry and egg products; salads such as egg, tuna, chicken, potato, and macaroni; bakery products such as cream-filled pastries, cream pies, and chocolate éclairs; sandwich fillings; and milk and dairy products.
2. Skin and hair infections: Staphylococcus aureus commonly colonizes many skin surfaces on the nasopharynx, and perineum; but can cause infection of these surfaces particularly if the cutaneous barrier has been disrupted or damaged.
3. Systemic infections: Staphylococcus aureus commonly causes infective endocarditis in IV drug abusers; osteomyelitis, sinus infections in the general population; and epiglottitis in young children.
4. Nosocomial infections: Methicillin resistant Staphylococcal aureus (MRSA) is a strain of the bacteria that is commonly implicated in nosocomial infections. Risk factors for MRSA colonization or infection in the hospital settings include prior antibiotic exposure, admission to an intensive care unit, surgical incisions, and exposure to infected patients.

Staphylococcus aureus is a type of Staphylococcus aureus that is resistant to the antibiotic methicillin and other drugs in this class. Staphylococcus aureus. Staphylococci can be found normally in the nose and on the skin. Staphylococcal aureus disease is 1-6 hours. Diagnosis Staphylococcal aureus gastrointestinal illness can be diagnosed by isolating the preformed toxins from the contaminated food item.