List general characteristics of bacteria in the genus Staphylococcus (gram, shape, arrangement, catalase status)
Gram +, cocci, clusters, catalase +
Staphylococcus is catalase ____ and oxidase ____
What are some of the dz's caused by staphylococcus?
#1 cause of infective endocarditis, nosocomial bloodstream infections, and orthopedic ones
Septic shock mortality rate is high
What is the most virulent species of the Staphylococcus genus?
What do MSSA and MRSA stand for?
Methicillin-susceptible Staph. aureus
Methicillin-resistant Staph. aureus
Most MRSA infections in hospitals are typically acquired where?
What causes foodborne intoxication with staphylococcus?
Ingestion of heat-stable enterotoxin (transmitted by food handlers)
Describe the onset of food intoxication seen with staphylococcus
Rapid onset (within 1-6 h)
What are some of the clinical syndromes seen with Staph aureus?
What are the major virulence factors of S. aureus?
Adherence factors (Protein A, fibronectin-binding proteins, collagen-binding proteins)
Other secreted enzymes
What is the main type of infections is most common with S. aureus?
Skin/soft tissue infection (95%)
-cellulitis, impetigo, abcess/furuncle
What this be?
What is this? Which toxin is responsible?
Scalded Skin Syndrome (SSS) - Ritter's syndrome
Exfoliative toxins ETA and ETB
What age group is most at risk for SSS?
Children under 5
This skin desquamation is a result of which toxin? What is the name of this syndrome?
Toxic Shock Syndrome (TSS) - shock w/n 48 hrs
What is the mechanism of TSST-1 toxin?
Binds T cell receptor and MHCII of APC => constituitively active
Leads to massive release of cytokines -> hypotension, shock, and death
Infection of bone or bone marrow
What cardiac abnormality is associated with S. aureus?
What are some of the Respiratory tract infections associated with S. aureus?
Pneumonia, empyema, cystic fibrosis
What are the two topical rx options for S. aureus?
Bacitracin (MSSA > MRSA)
Mupirocin (MSSA and MRSA)
What are the different rx options for MSSA and MRSA?
What morphilogical change is associated with VISA? VRSA?
VISA (Vancomycin-intermediate S. aureus) - thickened cell wall
VRSA (Vancomycin-resistant S. aureus) - acquired resistance plasmid from Enterococci
What is the coagulase status of S. epidermidis?
What are some of the opportunistic infections of S. epidermidis?
Primary implant, catheter and prosthetic joints, bacteremia (biofilm)
What type of infections is S. saprophyticus famous for?
UTIs in sexually active young women
What is produced by S. epidermidis that inhibits growth of other gram positiives?