gram neg cocci
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- gram stain of neisseria and moraxella:
-
gram negative diplococci
frequently intracellular within PMNs - growth requirements of neisseria and moraxella:
- fastidious and aerobic; require increased CO2
- oxidase test on both genera:
- positive; staph and strep are negative; a good confirmation that you didn't or did overdecolroize
- neisseria gonorrhoeae growth characteristics
-
BAD on BA
GOOD on CA
maybe takes 3 days to grow; incubate 72 hrs before calling neg; hates cold - special agar for gonorr growth:
- Thayer Martin Agar
- thayer martin agar contains:
-
CA base
VCN inhibitor
-Vancomycin - to inhibit GPC
-Colistin - to inhibit GNB
-Nystatin - to inhibit yeast - special about MTM (modified thayer martin)
- contains trimethoprim to inhibit Proteus from swarming over everything (along with VCN)
- colonial morphology of gonorrhoeae:
- small, translucent, tan, raised, slightly mucoid
- two other agars (other than thayer martin)
-
New york city
martin lewis - whats a jembec plate?
- special plate for transporting genital specimens; inoculate to plate immediately so growth will start right away (72 hrs). With water droplet CO2 is released to enhance growth
- when males have intracelluar gndc:
- can presumptively say they have gonorrhea
- what if women have intracellular gndc in their genital specimen?
- could be acinetobacter or moraxella; need further testing
- 3 confirmatory I.D. methods for gonorrheae:
-
1. Carb tests (CTA) cystine trypticase agar
-surface growth (aerobic)
-only ferments Glucose
2. Does NOT grow on nutrient agar
3. 2 Alternate tests:
-Rapid carb tests
-immunological I.D. - disease caused by neisseria gonorrheae
- gonorrhea
- 4 virulence factors of n. gonorrheae
-
1. pili
2. IgA protease (inhibit secretory IgA)
3. endotoxin
4. Capsule - symptoms of gonorhea
-
female
-cervicitis/vaginitis
-asymptom or itch/discharge
male
-urethritis, dysuria
-purulent discharge (thick and yellow)
BOTH: proctitis - how do you treat gonorrhea?
-
-resists penicillin, so
-injection of ceftriaxone
or
-oral doses of ciprofloxacin
-or, azithromycin in flouroquinolone-resistant gay men. - 3 complications caused by gonorrhea
-
-PID pelvic inflam disease (fallop tube)
-gonococcal arthritis (bact in joints)
-septicemia - two additional diseases other than gonorrhea in genitals:
-
-Gonococcal pharyngitis
-Neonatal opthalmia - growth characteristics of neisseria meningitidis
-
-not as fastidious as gonorrhea; still best on CA in incr. co2 tho.
PATTERN DIFFER:
-this grows in CLUSTERS, where
-gonorrh. grew in PAIRS - tests for identification of neisseria meningitidis
-
-how it utilizes carbs (see chart)
-nutrient agar
-dnase - alternate tests for meningitidis i.d.
-
immunological
direct tests - how meningitidis is transferred
-
-droplet
-direct - symptoms of meningitis
-
headache, stiff neck, fever, chills, vomit, (all mening. have this)
IN MENINGOCOCCAL: PETECHIAL LESIONS - what species causes meningitis with petechial lesions? what are they?
-
neisseria meningitidis
grows lesions - specimen for detection of meningitis
- spinal fluid
- how to treat meningitis
- chloramphenical
-
how many species of saprophytic neisseria?
normal floral site -
7
mouth - special i.d. trick for neisseria saprophytics:
- they grow on nutrient agar!
- which saprophytic is usually responsible IF they cause a disease?
- n. lactamica
- which is the only lactose-utilizing neisseria?
- n. lactamica
- which is the only gnc to produce dnase?
- moraxella catarrhalis
- 4 diseases caused by moraxella catarrhalis:
-
-otitis media in infants
-sinusitis in elderly/immunocomp
-pneumonia
-meningitis - how to treat moraxella cataharllis, why?
- with erythromycin; 85% produce b-lactamase
- What agars does N. gonorrhoeae grow on:
-
-CA
-Thayer Martin Agar
-Modified Thayer Martin
-Jembec
-Martin Lewis