Neisseria spp.

Question 1

Neisseria spp

Morphology

Answer 1

Gr- cocci, pairs (coffe-bean)

Question 2

Neisseria spp

Diagnostic criteria

Answer 2

Oxidase +
catalase -
produce acid from carbs
require CO2 enriched environment (35-37°)

Question 3

Neisseria meningitidis

Virulence factors

Answer 3

1. polysaccharide capsule (K AG) - evasion
2. Pili - adhesion to non-ciliated epithelial cells
3. porins - nutrient & waste product passage through membrane
4. Opa proteins - adhesion to epithelial & phagyocytic cells making opaque colonies
5. LOS - lipooligosaccharide = endotoxin released during rapid growth –> systemic symptoms
6. IgA proteases - evasion & invasion, breaking down mucosal IgAs.
7. Human factor H binding protein - downregulates C’ system.

Question 4

Neisseria meningitidis

Meningitis - characterized & symptoms

Answer 4

1. inflammation of meninges + thrombosis of blood vessels + exudation of PMNL ==> brain covered in thick exudate
2. abrupt onset, headache, meningeal signs (neck stiffness), fever and in young children non-specific symptoms: vomiting and fever

Question 5

Neisseria gonorrhea

virulence factors

Answer 5

1. pili (antigenic variations)
2. porins - additionall funcitons of interfering with neutrophil degranulation, facilitating bacterial invasion and resistance to C’ system
3. Opa proteins
4. LOS
5. IgA protease
6. Beta lactamase - (not all strains)

Question 6

Neisseria gonorrhea

Gonorrhea - incubation, symptoms (men & women)

Answer 6

1. 2-5days
2. Men: urethra, symptomatic; purulent urethral discharge & dysuria. Rare complications: epididymitis, prostatitis & periurethral abscesses
3. Women: cervix; vaginal discharge, dysuria & abdominal pain. Complications: ascending genital infections (ex. salpingitidis, tuboovarian abcsesses & PID, pelvic inflammatory disease).
   Initial infection can be asymptomatic –> increased PID, ectopic pregnancy, infertility, destructive arthritis and disseminated infection risk

Question 7

Neisseria gonorrhea

Gonococcemia - characteristics, symptoms

Answer 7

1. complication of initial N. gongorrhea infection, more common in women as they are mostly asymoptymatic –> further progression.
2. fever, migratory arthralgias, suppurative arthitis in writsts, knees & ankles and pustular rash with erythematous base on extremities.

Question 8

Neisseria meningitidis

Meningococcemia - cause, symptoms, prophylaxis

Answer 8

Can be with/without meningitis
LOS (endotinemia) –> thrombosis of small blood vessels, multiorgan development.
Symptoms: (additional to meningitis if present)
- Petechial skin lesions on trunk & lower extremities –> large hemorrhagic lesions.
- Multiorgan failure (including adrenal gland)
Prophylaxis: specific (conjugated polysaccharide vaccine).

Question 9

Neisseria gonorrhea

Prophylaxis

Answer 9

Nonspecific

Question 10

Neisseria gonorrhea

Other diseases

Answer 10

• perihepatitis
• purulent conjunctivitis
• anorectal gonorrhea
• pharyngitis