5. Neisseria + Moraxella Flashcards
Neisseria GS
GNDC
Kidney bean shaped
often intracellular
Oxidase positives
Neisseria and Moraxella
Neisseria always considered a pathogen
NGON
Neisseria
All Neisseria are capnophiles, but —- requires CO2
NGON
Neisseria endotoxin
LOS
LOS is lacking the…
O antigen
Neisseria compete with the host for —-
iron
prevent development of NGON vaxx
constant alterations to pili antigens
Swab used for NGON collection
plate within —- hours of collection
rayon/dacron
6
NGON incubation requirements
35°C
3-5% CO2
humidity
up to 3 days
medium that selects for Neisseria
Thayer Martin
System used to grow and transport NGON, no longer used much anymore
JEMBEC
—– gives a mixed culture appearance
NGON
CTA ingredients, besides the sugar
cystine, peptones, phenol red pH indicator and 0.25% agar
GS is good for diagnosing NGON in…..
symptomatic males
why is GS no good for diagnosing females with NGON?
which other NGON infections is GS not good for?
Females have other GU flora organisms that mimic NGON on gram stain
pharyngeal and rectal
non-culture method of IDing NGON, never used for children
Nucleic acid amplification test (NAAT)
nucleic acid probe signal amplification is used on NGON in which samples?
urogential and conjunctival specimen swabs
Nucleic Acid Probe Signal Amplification turnaround time
downside
2 hours
must verify results, false positives occur
NAAT can be used on which types of samples?
endocervix, vagina, urethra, and urine
Pros and Cons of NAAT
Very sensitive, faster than culture, more specific, does not require viable organisms, less stringent collection and transport requirements
Expensive, some false positive results in certain settings, lack of antibiotic resistance data
NGON incubation
2-7 days
male vs female NGON presentation
male: Usually acute and symptomatic; if left untreated, 90% spontaneously resolve
female: About 50% are asymptomatic; Potential for complications if left untreated
pustular petechiae
NGON
What is a problem of NGON blood cultures and how do we solve it?
sodium polyanethol sulfonate anticoagulant is inhibitory, but if we draw at least 8 mL, it is diluted enough to recover organism.
prophylactic for ophthalmia neonatorum
1% silver nitrate drops or 0.5% erythromycin ointment
begins when NGON ascends into the fallopian tubes
pelvic inflammatory disease
If NGON is able to grow on BAP, it will look like…
tiny pinpoint
NGON ID methods (6)
CHO utilization
Enzymatic procedures
DNA probe culture confirmation
NAAT
MALDI-TOF
16sRNA gene sequencing
super NGON is resistant to…
ceftriaxone and azithromycin
NMEN grows on…
most non-selective media with blood
NMEN must be handled in a ——- safety hood
class II
there are —- NMEN capsule serotypes and —- is the worst one
13
B
Why is serotype B the worst in NMEN?
Homologous to brain tissue, not immunogenic.
Why is NMEN so pathogenic?
LOS
release of blebs
10-1000x more endotoxin is released than other GNs
most common NMEN serotypes
A, B, C, Y, W135
direct detection method of NMEN
Bacterial latex agglutination (BLAT)/Direct antigen test (DAT)
Sx of NMEN meningitis
Confusion, rash, headache, fever, nuchal (neck) rigidity, vomiting, confusion, photophobia
mortality rate for meningitis w/o sepsis
3-10%
meningococcemia mortality rate and onset
Onset 6-8 hours
Death within 12-48 hours
50% mortality even with treatment
complicaition of meningitis that involves the body using up all the clotting factors and then uncontrollable bleeding
disseminated intravascular coagulation (DIC)
Waterhouse-Friderichsen syndrome
Complication of NMEN DIC
Bilateral hemorrhage of the adrenal glands
2 populations at risk for NMEN
3 months to 1 year
Older teenagers and young adults
organism that can create antibodies to NMEN
E. coli serotype K1
Africa has a regional belt of —– infection from Dec to March
NMEN
NMEN serotypes that the vaccine covers
A, C, Y and W135
saprophytic
nonpathogenic
some nonpathogenic Neisseria species produce a —— pigment
xanthochromic
(yellow)
—— and —— will grow on TM (not NGON or NMEN)
——- will only grow on initial isolation
N. lactamica and M. catarrhalis
N. cinerea
——– can be mis-IDed as NGON with rapid enzyme tests
why?
N. cinerea
Carbonic acid created from the production of carbon dioxide can result in a weak acid reaction
butyrate esterase allows MCAT to hydrolyze….
indoxyl-butyrate
3 most common causes of otitis media
M. catarrhalis
S. pneumoniae
H. influenzae
COPD is a risk factor for ——- infection & pneumonia
MCAT
Intracellular GNDC in a lower resp sample could be ——-, while extracellulars could be ——-
MCAT
Neisseria normal flora
Why do antibiotics make NMEN patients worse at first?
Cell lysis releases LOS endotoxin
4 antibiotics in TM agar and what they inhibit
Vancomycin—GPC (and 10% of NGON)
Anisomycin—yeasts
Trimethoprim—Proteus swarming
Colistin—GNRs and normal flora Neisseria
oxidase reagents
Tetra-methyl-para-phenylenediamine dihydrochloride
Dimethyl-para-phenylenediamine dihydrochloride
wait —– for Mcat disc to change color
2 mins
NGON clinical significance (7)
gonorrhoea
septic arthritis
ophthalmia neonatorum
pelvic inflammatory disease
proctitis
pharyngitis
tonsilitis
NMEN clinical significance (2)
meningitis
meningococcemia
nonpathogenic Neisseria are rare causes of…
endocarditis
N. cinerea clinical significance
proctitis
MCAT clinical significance
otitis media
bronchitis
pneumonia
acute maxillary sinusitis
NGON glucose-maltose-sucrose-lactose
POS neg neg neg
NMEN glucose-maltose-sucrose-lactose
POS POS neg neg
NLAC glucose-maltose-sucrose-lactose
POS POS neg POS
NMUC glucose-maltose-sucrose-lactose
POS POS POS neg
NSIC glucose-maltose-sucrose-lactose
POS POS POS neg
NCIN glucose-maltose-sucrose-lactose
neg neg neg neg
MCAT glucose-maltose-sucrose-lactose
neg neg neg neg
only positive DNAse
MCAT
GNDC with B-lactamase
NGON
MCAT
screen the others
clue that otitis media might be caused by MCAT
no susceptibility to B-lactams
