Neisseria and Moraxella catarrhalis

Question 1

Obj1. List the microscopic, macroscopic, and common biochemical characteristics of the genera Neisseria and Moraxella.

Answer 1

• Gram negative diplococci (“kidney bean or
  kissing morphology”)
• Aerobic
• Oxidase positive
• Catalase positive

Question 2

Obj2. Discuss the natural habitats of the organisms discussed in class.

Answer 2

Moist mucous membranes of humans and other animals (i.e. oropharynx/respiratory tract and urogenital tract)

Question 3

Obj3. Identify the general growth requirement of the “pathogenic” species.

Answer 3

• Warmth (37 deg. C)
• Humidity
• CO2
• Enriched media, preferably

Question 4

Obj4. Recognize the purpose and atmospheric conditions of a “Candle Jar” used for incubation.

Answer 4

The purpose of this “Candle Jar” was to provide an environment in which pathogenic Neisseria would grow due to the increase of CO2, provided by the burning candle

Question 5

Obj.5 Discuss the significance of each of the virulence factors mentioned in class.

Answer 5

• Receptors for human transferrin (BOTH
  requires iron and competes for binding
  sites)
• Capsule (resistant phagocytosis) – N.
  meningitidis
• Pili (attachment, phagocytosis, exchange
  of genetic material) – N. gonorrhoeae
• Lipooligosaccharide (LOS)/endotoxin
• IgA protease

Question 6

Obj.6 Discuss the general principles of media and biochemicals used to identify Neisseria and Moraxella species.

Answer 6

Non-enriched media
- reserved for non-pathogenic spp.
Enriched media - sterile sources
- CHOC
Selective, enriched media – non-sterile sources
- TM/ML

Biochemicals:
*Rapid sugar utilization
- Test for preformed enzymes (glucose,
maltose, sucrose, lactose)
- pH indicator (sugar utilization = acid =
yellow)
*ONPG
- lactose substitute that does not require a
permease enzyme to enter cell
- organisms w/ beta-galactosidase activity
cleave ONPG
- Positive test = yellow color change

Question 7

Obj.7 Analyze biochemical results for Neisseria and Moraxella to determine species identification or recommend further testing.

Answer 7

Review slides/audio for description

Question 8

Obj.8 List the names of the “pathogenic” (Group I) and the “non-pathogenic” (Group II and Group III) species as discussed in class.

Answer 8

Group I
* N. meningitidis
* N. gonorrhoeae

Group II
* N. lactamica
* M. catarrhalis (v)
* N. cinerea (v)

Group III
* N. mucosa
* N. sicca
* N. subflava
* N. flavescens

Question 9

Obj.9 Compare and contrast the growth properties on CHOC and ML agars of the “pathogenic” species and the “non-pathogenic” species of Neisseria and Moraxella.

Answer 9

ALL species will grow on CHOC agars based on its enriched media, specifically used for sterile sites

ML is enriched and selective; therefore, pathogenic spp. are more readily observed

Some non-pathogenic? (Group 2) are having variable breakthrough growth on ML agars, as well – however, most display NO growth

Question 10

Obj.10 Evaluate direct specimen smears for N. gonorrhoeae (GNID or joint fluid) and N. meningitidis (in CSF).

Question 11

Obj.11 Recognize the species of Neisseria that is NEVER considered normal flora

Answer 11

N. gonorrhoeae

Question 12

Obj.13 Recognize the progression of increasing resistance observed with N. gonorrhoeae and how it affects treatment.

Answer 12

Review slides/audio for description

Question 13

Obj.14 Discuss why GNID direct smears are performed on males but should not be relied on for diagnosis of gonorrhea in females.

Answer 13

*In males, little/none normal flora is of the Neisseria spp.
*In females, their normal flora DOES contain Neisseria spp. in the vagina; therefore, you cannot tell the difference