Question | Answer |
Strep catalase | - |
Strep metabolism | aerotolerant; ferments sugars -> lactic acid |
What needs to be used to enrich agar to support growth? | blood |
How many serologicag groups of strep? | 20 |
what is preliminary grouping based on? | hemolysis of 5% sheep blood |
what is beta hemolysis | complete |
what is alpha hemolysis | incompte |
what is gamma hemolysis | no hemolysis |
What are teh characteristics of group A strep? | capsule of hyaluronic acid; fibrils; peptidoglycan layer; T and R protiens |
what soluble virulence factors are seen with group A strep | streptokinase, streptodornase, hyaluronidase, erythrogenic toxin, NADase, streptolysins |
how is step A acquired | another infected individual or a carea; |
how is grp A able to spread? | resists phagocytosis and spreads thru tissues |
how does grp A strep damage teh body? | ellicites a strong inflammatory response and cuases release of chemotoxins for WBC |
how does group A activate complement? | alternate pathway |
What does lysis of WBC cause? | release of lysosomal enzymes and then damage to surrounding tissue |
what is streptolysin O | oxygen labile, antigenic |
what is streptolysin S? | oxygen stabile, nonantigenic |
How is pharyngitis diagnosed? | thorat cultures then direct antigen test |
what are grop A fibrils made up of? | M-proteina dn lipoteichoic acid |
How are S. pyogenes invasive infections diagnosed? | gram stain and culture; blood culture if bacteremia is suspected |
What antibodies are used to diagnose S. pyogenes? | antistreptolysin O; streptozyme test |
What is pharyngitis | sore throat |
what is scarlet fever? | erythogenic toxin produced by grp A causing rash and strawberry tongue |
What strep is grp B strep/ | S. agalactiae |
what does s. agalactiae cause | septicemia, meningitis and pneumonia in neonates |
what is group D strepe | enterococcus and S. faecalis |
what does diseases does group D strep cause? | UTI, sound infection; sepsis |
What diseases does alpha strep (viridans strep) cause | subacute endocarditis |
what cuases dental caries | s. mutans |
what group is s. mutans? | alpha |
what dieseases does s. pneumonia cause? | pneumonia, otitis media, sinusitis |
treatment for strep? | PCN |
why is strep treated for prevention? | PCN G or oral PCN for 10 days to prevent rheumatic fever |
what are general characteristics of pseudomonas aeruginosisa? | gram - fermenter; motile with polar flagella; oxidase positive; obliage aerobes; opportunistic pathogen; green |
what color is P aeruginosa? | green |
P. aeruginosa oxidase; | + |
what does P. aeurginosa grow at? | 42 degrees C |
what are teh virulence factors of P aeruginosa | pili, polysaccharide capsule, endotoxin, exotoxin A; inhibits protein syntehiss; tissue necrosis; many extra ceullualr enzymes |
How does P. aeruginosa inhibit protein synthesis? | causes ADP-ribosylation of elongation factor 2 |
what are the common infections of P. aeruginosa? | ecthyma gangrenosum; infect immunocompromised with compromised physical barriers (burns; super infections after antibiotics; respirator pneumonia) folliculitis from hot tubs |
How do you prevent P. aeruginosa | clean rooms adn steralize hospigtal equipment; replace palstic tubing; minimize unnecessary broad-spectrum antibiotics |
how do you treat P. aeruginosa? | aminoglycoside + pipercillin or ticarcillin by IV |
What are characteristics of acinetobacter? | oxdiase negative; nonfermentative, nonmitile, pleomorphic organisms |
what does Acinetobacter anitratus cause? | noscomial infections similar to pseudomonas |
what does Acinetobacter baumanii cause? | opptorunistic infections; mutliple drug resistant; seen in American soldiers wounded in iraq |