MIDTERM 01 - Gram-Positive Cocci Flashcards
Gram-positive spherical cells arranged in grapelike irregular clusters
Staphylococci
Staphylococci produces __________, which converts H2O2 to H2O and O2
Catalase
2 Staphylococcus aureus enzymes (CC)
Coagulase, Clumping factor
Clots oxalated or citrated plasma (Staphylococcus aureus enzymes)
Coagulase
Adheres organism to fibrinogen and fibrin (Staphylococcus aureus enzymes)
Clumping factor
Lyse many cells and creates pores that cause release of inflammatory mediators (Staphylococcus aureus toxins)
Hemolysins
Is a superantigen; produces the generalized desquamation of staphylococcal scaled skin syndrome (Staphylococcus aureus toxins)
Exfoliative toxins
Is a superantigen that binds to MHC-II molecules which promotes the manifestations of toxic shock syndrome (Staphylococcus aureus toxins)
Toxic shock syndrome toxin-1 (TSST-1)
Is heat stable, resistant to gut enzymes, and causes food poisoning (Staphylococcus aureus toxins)
Enterotoxins
Characterized by a localized abscess (Staphylococcus aureus clinical findings)
Furuncle/Carbuncle
Characterized by a local infection of superficial layers of skin, especially in children (Staphylococcus aureus clinical findings)
Impetigo/Pyoderma
Characterized by a supparation (abscess) that occurs in other parts causing endocarditis, osteomyelitis, meningitis, and pneumonia (Staphylococcus aureus clinical findings)
Bacteremia
Supparation in blood vessels of the metaphysis of a long bone
Osteomyelitis
Its incubation period is 1-8 hours; characterized by symptoms that include N/V, diarrhea, and fever (Staphylococcus aureus clinical findings)
Food poisoning
Characterized by an abrupt onset of high fever, vomiting, diarrhea, myalgia, scarlatiniform rash, and hypotension with cardiac and renal failure in most severe cases (Staphylococcus aureus clinical findings)
Toxic shock syndrome
Characterized by redness and tenderness of the central face, neck, trunk, and intertriginous zones (Staphylococcus aureus clinical findings)
Scalded skin syndrome
Enzyme that hydrolyzes β-lactam antibiotics; give β-lactamase resistant penicillins
β-lactamase
Gene that gives resistance to β-lactamase resistant penicillins due to low affinity PBPs; give vancomycin
mecA gene
Bacteria that causes 75% of coagulase-negative staphylococcal infections (Streptococcus species)
Streptococcus epidermidis
Bacteria that is part of the normal flora of the skin, respiratory tract, and GIT; relatively common cause of UTIs in young women (Streptococcus species)
Streptococcus saprophyticus
Gram-positive spherical cells arranged in pairs or chains
Streptococci
Grouping based on Lancefield antigens (carbohydrates) present in the cell wall
Lancefield grouping
N-acetylglucosamine (Lancefield group)
Group A
Rhamnose-glucosamine (Lancefield group)
Group B
Rhamnose-N-acetylgalactosamine (Lancefield group)
Group C