Gram-Negative Cocci Flashcards
the 3 Gram-neg cocci?
Neisseria meningitidis; Neisseria gonorrhoeae; Moraxella catarrhalis
N meningitidis, vir factors?
GNC; capsulated; LOS – endotoxin; antigenic variation (fimbriae and opa)
diff btwn N meningitidis and gonorrhoeae?
N meningitidis encapsulated (A/ B/ C/ Y/ W135)
conj vacc for N mening
not for B only, so A/C/Y/W135 – quadrivalent vacc
how does grp B N mening vacc work?
not via capsular Ag; subcapsular peptides
N mening; epid?
nasopharyngeal carr ~10%; transm = resp drops; outbreaks = institutions/close contact/mening belt in Africa; meningococcal disease most common in young children
meningococcal disease most common in adults?
F
what can commonly cause bac mening in young children?
N mening; Hib; Spn
meningococcal rash; desc
initially macular but progresses; hemorrhagic rash (petechiae, purpura, ecchymoses)
Tumbler test; desc
+ve if rash does not blanch upon pressure; significant of meningcoccal inf
why does nonblanching rash occurs in meningococcal inf?
its not due to dilated blood vessels (which blanch upon pressure); its due to rupturing and bleeding of the small blood vessels
rashes can be hard to see on a dark-skinned patient. where can rashes better be seen on such pts?
at the conjunctiva, eg conjunctival petechiae
meningococcal disease; desc?
fulminant meningococcemia; meningitis (or can be both)
desc Waterhouse-Friderischen
hemorrhagic adrenalitis (due to hemorrhage into the adrenal glands) that usually occurs secondary to severe meningococcal infection
Dx of meningococcal?
Always blood culture; location as indicated (eg, CSF, throat, other sites). but molecular Dx increasingly impt
