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
Tx meningococcal
benzylpeni – R still v uncommon but dont clear nasophar carr; cetriaxone – clears nasophar carr
rmb surgical debridement
high risk pts for mening?
asplenic or pts w/ hematologic diseases; certain travellers (eg, Hajj pilgrims, mening belt); local outbreaks (must perform prophyl for close contacts)
meningo vacc
polysacc (not so good infant – rmb infants most vuln)
conj vacc (ie polysacc + prot) = quadrivalent (A/C/Y/W135) or monovalent (country specific)
subcapsular protein-based = grp B vacc (eg, 4CMenB)
ABx as chemoprophyl for meningo?
rifamipicin, ciprofloxacin, ceftriaxone + vacc
mening inf rarer complics?
pneumonia; pericard; endocard; conjuctiv; arthri
gonorrhea in males SS?
urethritis – discharge, dysuria, local SS (eg epididymitis)
Dx of male gonorrhea?
Gram stain!!! GNC, intracell, diplococci
recurr gonorrhea can lead to____?
urethral strictures
gonorrhea female inf can cause?
endocerv inf (SS = vag disch/ dysuria/ intermenstr bleeds); salpingitis (PID); Fitz-Hugh-Curtis (perihepatitis)
pyosalpinx can be observed in____?
acute salpingitis
why Gram stain less helpful for Dx in female gonorrhea?
backgroud has many other bacteria!!
which medium recover N gonorrhoeae?
modified Thayer-Martin medium (5% choc sheep blood w/ ABx)
gonorrhea can lead to? (for all ppl)
throat inf (usually asymp); proctitis; conjuncitivitis (think of ophthalmia neonatorum!!); dissem gonococcal inf; gonococcal arthri
female gonococcal-inf pts usually ________?
asymp at first – carriage & reservoir
Dx for gonorrhea in general?
NAT using urine samples, throat and rectal swabs, male = urethral, female = endocervical/ LVS
Gram strain for clean sites (eg, male urethra, joint fluid)
culture – in co2 enrinched medium (rmb charcoal transport medium!!)
Tx gonorrhea??
ceftriaxone IM 500mg
which to avoid for Tx of gonorrhea?
unless proven to be sus, penicillin & ciprofloxacin; increasing res to azithromycin as well (taken off first line agents in 2020)
what can M catarrhalis cause??
opportunistic chest infs (gen in ppl w/ comorbs)
Tx of M catarrhalis inf?
Coamoxiclav usually effective
