Gram-Negative cocci Flashcards
General Neisseria atmospheric requirements
aerobic & capnophilic
Most Neisseria are oxidase-_______ and catalase-_______
positive, positive
General Neisseria morphology
diplococci attached side-to-side
N. elongatata & N. bacilliformis are exceptions because
they are catalase-negative and rod-shaped
N. weaver is an exception because
it is catalase-positive but rod-shaped
Neisseria are usual flora in these locations
upper respiratory and urogenital tracts
this Neisseria species is never normal flora
N. gonorrhoeae
the 2 primary Neisseria pathogens
N. gonorrhoeae and N. meningitidis
N. gonorrhoeae - major virulence factor
pili w/ antigenic variation
N. gonorrhoeae - other virulence factors
capsule; outer membrane proteins w/ antigenic variation; outer membrane porin proteins, lipooligosaccharide endotoxin, IgA protease
N. gonorrhoeae outer membrane proteins work by
causing production of useless antibodies
N. gonorrhoeae - modes of transmission
sexually or via birth canal
__% of men show symptoms of gonorrhoeae; __ - __% of women are _________
95; 20, 80, asymptomatic
Gonorrhoea complication in women
pelvic inflammatory disease (PID)
disseminated gonococcal bacteremia can lead to
gonococcal arthritis (#1 causative agent in teens and young adults)
occurs from infection during vaginal delivery
ophthalmia neonatorum
gonorrhoeal infections your newfangled sexual practices will give you
pharyngitis and anorectal infections
grow Neisseria on this agar in this atmosphere
modified Thayer-Martin agar in 3 - 5% CO2
component of MTM that inhibits gram-positive bacteria
vancomycin
component of MTM that inhibits gram-negative bacteria
colistin
component of MTM that inhibits yeast
nystatin
component of MTM that inhibits swarming Proteus sp.
trimethoprim
can you use a gram stain to presumptively identify N. gonorrhoeae?
yes, but only in penile specimens
positive oxidase reaction color change
pink to black
what is cystine trypticase agar?
agar with 1% of a single carbohydrate and a phenol red indicator
N. gonorrhoeae ferments ________
only glucose (sometimes weakly)
N. meningitidis ferments __________
glucose and maltose
N. lactamica ferments ________
glucose, maltose, lactose
N. sicca ferments ________
glucose, maltose, sucrose
advantage of nucleic acid assays
can use directly from specimen
define superoxol test & N. gonorrhoeae result
30% H2O2, N. gonorrhoeae shows immediate bubbling
strain of N. meningitidis that most commonly causes disease in infants
type B
some symptoms of meningitis
frontal headache, stiff neck, nausea and vomiting, sometimes fever
important clinical infection caused by M. catarrhalis
otitis media
tests to ID M. catarrhalis
asacrolytic; DNase positive; reduces nitrate
