Gram + Cocci Flashcards
Methlicillin Resistant Staph Aureus (MRSA)
Altered penicillin binding protein that are not interrupted by B-lactam
Tx- vancomycin or Ceftaroline
Staphylococcus Epidermidis
SSNA, catalase +, urease +, coagulase -, uses biofilm that aids in infection of foreign material (endocarditis of prosthetic heart valves)
Tx- vancomycin
Streptococcus Pyogenes
Group A Strep(GAS) - capsule of hyaluronic acid, streptokinase+, DNAse, B-hemolytic (streptolysin O), SPE > scarlet fever, TSS, necrotizing fasciitis; pharyngitis, cellulitis, eryseplas, impetigo
Post-pharyngeal infection - M protein > antiphagocytic, antibody cross-reactivity to mitral valves
Post-strep glomerulonephritis - immune complex mediated > dark urine, facial edema
Streptococcus pneumonia
Polysaccharide capsule, IgA protease, a-hemolytic, Greater susceptability in asplenia/Sickle cell, bile soluble, most common cause of community-aqcuired pneumonia, MOPS (meningitis, otitis media, pneumonia, sinusitis); tx- Macrolides, Ceftriaxone, Penicillins; Adult Vaccine- 23valent –> IgM production; Child Vaccine- 7/13valent, conjugated –> IgG production
Staphylococcus Aureus
Catalse +, coagulase +, fibronectin-binding protein (for adhesion), B-hemolytic (SBA), Yellow (mannitol), Protein A (Binds Fc, preventing complement activation), Causes: pneumonia, septic arthritis, abscesses, impetigo, acute bacterial endocarditis, osteomyelitis, scalded skin syndrome, TSS (superantigen TSST-1), rapid onset food poisoning
Tx - vancomycin, nafcillin
Streptococcus viridans
a-hemolytic, no capsule, bile insoluble - found in mouth/carries - adhesion due to dextran - common cause of infectious endocarditis on previously damaged heart valves
Enterococcus faecalis & faecium
can grow in 6.5% NaCl - bile resistant/insoluble - cause of UTIs, endocarditis, biliary tree infections - vancomycin resistant - tx- Linezolid/Tigecyclin
