Term
| What are the two (important) gram- cocci genera and species? |
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Definition
-Neisseria meningitidis & gonorrhoeae
-Moraxella catarrhalis |
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Term
| What is specific about Neisseria and how do we differentiate its species? |
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Definition
-Gram- *diplococci with flattened sides (like beans)
-Grown on *chocolate agar with some antibiotics to kill normal flora; ***Thayer-Martin agar*** (specific for pathogenic Neisseria)
-*Oxidase positive (turns phenylenediamine black)
-Both ferment glucose
-N. meningitidis has a **capsule and **ferments maltose, while N. gonnorrhoeae has neither (match the m's)
-Important to tell them apart bc both can be found in the oropharynx (one from being naughty lol) |
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Term
| What do we have to know about N. meningitidis? |
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Definition
-Common cause of **meningitis in young adults** which also presents with *vomiting and *petechial rash (pretty much dead after rash presents)
-Spread by resp. and has abrupt onset
-5-10% of people are asymptomatic carriers; think *crowded places like dorms, etc.
-Ferments **maltose and glucose
-Grows on *chocolate, but not blood agar (no hemolysis)
-**Large capsule; usually *group B strain (50%) which is only *weakly immunogenic (not included in vaccine)
-Has a unique **lipoOLIGOsaccharide endotoxin; causes the *DIC then death
-Also has an IgA protease and pili for oropharynx colonization
-***Repeat infections when late compliment deficient*** (need MAC to fight it apparently) |
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Term
| What kind of drug do we want to use with meningitis? |
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Definition
| -Cephalosporins are the safest to use |
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Term
| What about N. gonorrhoeae; ID factors (3)? Diseases (3)? Virulence (1)? |
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Definition
-Gram- kidney bean shaped **diplococci in neutrophils**
-**Thayer Martin medium
-Oxidase+ and **can't ferment maltose**
-Urethritis in males (*white pus drips), and cervix infections/PID in females (arthritis possible)
-Females are less symptomatic
-**Eye infections in infants-->can cause blindness
-Can also get *pharyngitis lol
-Has *pili that constantly have *antigenic variation
-Treat with ceftriaxone and add in doxycycline for the clap (often co-infected)
-Very resistant and has beta-lactamase |
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Term
| What is the disease and diagnosis for Moraxella? |
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Definition
-Moraxella catarrhalis is normal flora in upper resp.
-Can cause *otitis media and *sinusitis (less common than #1; Strep pneumo, and #2; H. influenza)
-Gram- diplococci |
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