Neisseria and Moraxella Flashcards
Habitat of Neisseriaceae
- Live on moist mucous membranes of man and other animals (oropharynx, genitourinary tract)
- In ecological niches, most do not produce disease
General growth requirements of the “pathogenic” species
Pathogenic species are fastidious
- Warmth (37C)
- Humidity
- CO2 (5-10%)
- Enriched media
General growth requirements of the “non-pathogenic” species
- Will grow on most primary media
- Usually do not require CO2 and/or 37C
Prupose of a “Candle Jar”
It replaces a CO2 incubator
- A capnophilic environment where CO2 is increased and O2 is decreased (NOT ANAEROBIC)
Atmospheric conditions of a “Candle Jar”
3% CO2 environment for culture plates
What are teh 3 types of culture media used to identify Neisseria and Moraxella?
- Non-enriched media
- Enriched media
- Selective, enriched media
What are the 3 selective, enriched media that contain antibioitics to inhibit normal flora in Neisseria and Moraxella?
- Modified Thayer Martin (MTM) → Chocolate
- Martin Lewis (ML) → Chocolate
- New York City medium (NYC) → Horse blood
Group II Neisseria species
“Commensals” often grow on selective media
- N. lactamica
- M. catarrhalis (v)
- N. cinerea (v)
Group III Neisseria species
“Commensals” = No growth on selective
- N. mucosa
- N. sicca
- N. subflava
- N. flavescens
- M. catarrhalis
Group I Neisseria species
“Pathogenic” = growth on selective media
- N. meningitidis
- N. gonorrhoeae
____ and ____ require iron and compete w/ host by binding transferrin
Pathogenic Neisseria:
N. meningitidis and N. gonorrhoaea
Why can’t you get gonorrhoaea from the lab?
N. gonorrhoeae have pili in virulent strains which are lost upon subculture
2 types of oxidase tests
- Filterpaper method
- Plate method
Laboratory identification tests of Neisseria and Moraxella (10)
***impossible to memorize!!!
Probes
- Oxidase Test
- Catalase Test
- Superoxol Test (30% H2O2)
- Biochemicals
- MALDI-TOF
- FA, co-aggultination
- Nucleic Acid Amplification Tests (NAAT)
- Enzymatic procedures
- Growth requirements
ONPG tests
- What does it detect?
- How long is the test?
- Color for pos and neg
- Detects late lactose fermentation
- 4 hour test
- Pos = yellow; neg = clear
N. gonorrhoeae
- Disease caused?
gent of gonorrhea (eye infections, septicemia, pharyngitis, arthritis)
- anogenital vs. non-genital infections
N. gonorrhoaea
- How diagnosis is made?
First day you get “suspicious or presumptive tests then you have to run confirmatory tests
First day “suspicious” or “presumptive” ways of identifying N. gonorrhoeae (5)
- Colonial morphology
- Oxidase
- Microscopic morphology
- ONPG
- Catalase
- Small, creamy, moist, transluncent-brownish colonies
- Oxidase positive
- GN diplococci
- ONPG negative
- Superoxol (30% H2O2) → strongly positive
“Presumptive” positive plus confirmation of N. gonorrhoeae by one of the following… (5)
- MALDI-TOF
- Probe from colony
- Fluorescent Ab
- Rapid/CTA sugars (glucose positive only)
- Enzymatic or coagglutination
____ confirming tests using different principles are required for isolates from patients less than 18 years old. Isolates must be ____
Two; frozen
N. gonorrhoeae
- Proper specimen collection
- Dacron or rayon swabs are used (cotton or calcium alginate swabs are inhibitory)
N. gonorrhoeae
- Lab methods for identification
- GNID slide test performed on male genital cultures
- GN diplococci must be seen w/in cytoplasm of segs - Target amplification nucleic acid test
N. gonorrhoeae
- Proper transport
- Amies transport medium
- Jembec plate and transgrow bottles
May be normal respiratory flora (humans only)
Neisseria meningitidis
N. meningitidis
- Diseases caused
- Meningitis
- Septicemia
- DIC
- Waterhouse-Friderichsen Syndrome
N. meningitidis
- Patient populations at risk
- Young adults are the most common age group (army barracks, college dorms, camps. etc.)
- Infants (not newborns) are also at risk
True or false: GNCs have to be intracellular
False: GNCs don’t have to be intracellular
Disease where there is a hemorrhage into adrenal glands, shock, then rapid death (12-24 hours)
Waterhouse-Friderichsen Syndrome
N. meningitidis
- Safety in lab
Work with under a safety cabinet b/c it’s a biosafety Level 2!
N. meningitidis
- CSF on what type of culture?
- Oronasopharyngeal on what type of culture?
CSF: cultured on noselective media (CHOC)
ORO: cultured on selective and nonselective media
First day “suspicious” or “presumptive” ways of identifying N. meningitidis (5)
- Colonial morphology
- Oxidase
- Microscopic morphology
- ONPG
- Catalase
- Small, creamy, moist, translucent-brownish colonies
- Oxidase positive
- GN diplococci
- ONPG negative
- Catalase positive
“Presumptive” positive plus confirmation of N. meningitidis by one of the following…(4)
- MALDI-TOF
- Probe from colony
- Fluorescent Ab
- Rapid/CTA sugars (glucose, maltose positive)
There is a vaccine for N. meningitidis recommended for military recruits, college students, micro lab workers, individuals w/ immune deficiencies, or travelers to endemic areas. NOT yet effective against ____
Serogroup B
Prophylactic treatment for at-risk individuals and for treatment of N. meningitidis index cases
Prophylaxis (Rifampin)
Usually non-pathogenic, mostly recovered from nasopharyngeal areas as usual flora, occasionally isolated from blood, CSF (pathogenic)
N. lactamica
N. lactamica
- Rapid/CTA sugars
- ONPG
- Glucose, maltose, lactose positive
- ONPG positive
In N. lactamica, late lactose fermenters can be misidentified as ____ unless ____ is run
N. meningitidis; ONPG
Moraxella catarrhalis
- Colonial characteristics
Gray-white colonies, difficult to emulsify, “hockey-puck” colonies
Part of normal human oropharyngeal flora, and common in children (ear, sinus infections)
Moraxella catarrhalis
What can be misidentified as N. gonorrhoeae? How do you tell them apart?
- N. cinerae can be misidentified as N. gonorrhoeae
- Colistin susceptibility testing (N. cinerae = S, N. gonorrhoeae = R)
N. sicca and N. subflava
- Colonial characeristics
Yellow to greenish, often dry or wrinkled colonies
