HSS 1101 Lecture Notes - Hospital-Acquired Infection, Coagulase, Endocarditis
Document Summary
Characterized by grape-like clusters: staphylococcus aureus: Toxins: cytotoxins, haemolysins, enterotoxin (food poisoning), exfoliative toxin (scalded skin syndrome in infants), toxic shock syndrome toxin 1. Problems caused: food poisoning, toxic shock, scalded skin syndrome, nosocomial infections, localized purulent infections (boils, styes, pustules), pneumonia, osteomyelitis, endocarditis. Hygeine, education etc important to prevent nosocomial infection: staphylococcus epidermis. Opportunistic pathogen found as part of normal skin/mucous flora since coagulase negative. Can cause post-operative infection after brain or open heart surgery, endocarditis after prosthetic valve insertion, shunt infection: staphylococcus saprophyticus. Found on skin and in environment; coagulase negative; can cause urinary infection. 3 methods of classification: haemolytic properties: a) b) c) Alpha: greenish brown zone of partial rbc destruction. Non haemolytic: no zone: carbohydrate c antigen: classifies strains as group a-o. Group a contains most common human pathogens, which are mostly beta haemolytic. Not all-inclusive: m-protein: divides the beta haemolytic group into over 70 serotypes, most of which are from group a.
