Staphylococcal Infections (pneumonia)Staph. pyogenes (coagulase-positive staphylococcus – syn. Staph. aureus) is responsible for a wide variety of suppurative conditions such as infected lacerations, styes, boils, carbuncles, abscesses, osteomyelitis, pneumonia, necrotizing enterocolitis and bacteraemia with pyaemic abscesses. Infection is derived from human or sometimes animal sources and the organisms can be grown from the nasopharynx and skin of up to 30% of healthy persons. The staphylococcus is readily spread from these sites and from clothing to contaminate the dust in which it survives in the dry state for weeks or months.
(pneumonia)(pneumonia) In hospital this organism is an important cause of wound infection, pneumonia and neonatal sepsis. Under suitable conditions it multiplies freely in food and milk and so is an important cause of food poisoning. However many infections, particularly boils, carbuncles and abscesses, are due to autogenous infection.
Strains of Staph. pyogenes resistant to antibiotics have increased in number since these drugs were introduced. Such strains are more commonly acquired in hospital and may give rise to small epidemics of infection. Elsewhere the majority of strains are sensitive to antistaphylococcal antibiotics although the production of penicillinase by many precludes treatment with benzylpenicillin. Necrotising enterocolitis is usually the result of the unrestricted growth of drug-resistant staphylococci in the gut following the suppression of other organisms by chemotherapy. The diarrhea, dehyderation and peripheral circulatory failure may be so severe as to resemble cholera.