MMSC 428 Final Exam (100% Errorless Answers)

Staphylococcus aureus correct answers -gram positive cocci in cluster -the most clinically significant staph, important cause of hospital acquired infections -produces protein A, extracellular enzymes and exotoxins -facultative anaerobe -medium sized B-hemolytic colonies -halotonic -mannitol fermentation + -catalase + -*coagulase +* -serological test for TSST-1 and DNA probes are good for detection -usually resistant to penicillin and methicillin staphylococcus aureus clinical manifestations correct answers -furuncle: large, raised suppurative dome shaped abscess (boil) due to infection of Staph aureus in oil gland or hair follicle -carbuncle: furuncle lesion progresses deeper and causes more invasive infection in lower skin, causing systematic symptoms and fever -impetigo: bullous (5 mm) pustules filled with fluid surrounded by erythema typically seen on the face of children -cellulitis: infection of connective tissue that leads to inflammation -staphylococcal scalded skin syndrome (SSS): exfoliative dermatitis caused by infection with staph aureus that releases exfoliatin toxin, leading to red, peeling skin that resembles 2nd degree burn (infants and neonates mainly) -toxic shock syndrome (TSS): staph aureus infection releases TSST-1 super antigen and enterotoxin B to cause systemic symptoms (fever, kidney and liver damage, vomiting, diarrhea, muscle ache and rash) that can progress to hypotension and shock (menstrual and nonmenstrual forms) -intoxication food poisoning: enterotoxins A, D and B contaminate food and leads to severe projectile vomitting and diarrhea -nosicomial infections: wound infection, osteomyelitis, biofilm on body implant -head and neck infections in children antibiotic resistant staphylococcus aureus correct answers -MRSA (methicillin resistant) -VISA (vancomycin intermediate) staphylcoccus lugdunensis correct answers -gram positive staphylococci -very virulent and clinically significant, causes similar infections to Staph aureus, just seen less often -*ODC +* -coagulase - -PYR + -mannitol - -nonhemolytic -oxacillin resistant -causes skin abscesses, meningitis, septicemia, septic shock and UTI