IIA. Systemic Bacteriology | 5. Neisseria. Veillonella. Moraxella. Acinetobacter Flashcards
I. Neisseria - General features of Neisseria
1. What are the features of Neisseria?
- Obligate human pathogens
- Cell wall: LOS (lipo-oligosaccharide) instead of LPS (inflammation!)
- Oxidase positivity (see practical class)
I. Neisseria - General features of Neisseria
2. Describe Microscopic morphology of Neisseria?
Bean-shaped Gram-negative diplococci
(N. meningitidis: capsulated)
I. Neisseria - General features of Neisseria
3. Describe cultivation of Neisseria?
- Very susceptible (fastidious) bacteria
- Cultivation only on chocolate agar, in 5% CO2
I. Neisseria
4. What are the 2 examples of Neisseria
- Neisseria gonorrhoeae (gonococcus)
- Neisseria meningitidis (meningococcus)
I. Neisseria - Neisseria gonorrhoeae (gonococcus)
5A. What is the transmission of Neisseria gonorrhoeae (gonococcus)?
- sexual (STD)
- perinatal (through birth canal) → conjunctiva of newborn
I. Neisseria - Neisseria gonorrhoeae (gonococcus)
5B. What is the clinical picture of Neisseria gonorrhoeae (gonococcus)?
- men: acute urethritis: dysuria, burning pain, purulent exudate („Bonjour-drop”)
- women: cervicitis, urethritis, but often asymptomatic; vaginitis in teenagers
- blenorrhoea (ophtalmia) neonatorum → blindness!
I. Neisseria - Neisseria gonorrhoeae (gonococcus)
5C. What is the Microscopic morphology of Neisseria gonorrhoeae (gonococcus)?
– specimen: purulent exudate
– direct Gram staining (1) or methylene blue staining (2)
– Gram-negative diplococci, seen intracellularly
I. Neisseria - Neisseria gonorrhoeae (gonococcus)
5D. Describe the cultivation of Neisseria gonorrhoeae (gonococcus)?
I. Neisseria - Neisseria gonorrhoeae (gonococcus)
5E. What is the treatment for Neisseria gonorrhoeae (gonococcus)?
- earlier: penicillin, today rather 3. gen. cephalosporins (ceftriaxon)
- if chlamydia also suspected: additional macrolide (azythromycin)
I. Neisseria - Neisseria gonorrhoeae (gonococcus)
5F. What is the Prevention for Neisseria gonorrhoeae (gonococcus)?
- for newborns: earlier Credé eye drops (silver acetate); today rather antibiotic containing eye drops (tetracycline or macrolide)
- for adults: condom
I. Neisseria - Neisseria meningitidis (meningococcus)
6A. What is the transmission of Neisseria meningitidis (meningococcus)
- respiratory droplets
- nasopharyngeal colonisation precedes disease [asymptomatic carriage!]
- from the nasopharynx to CNS: always through blood (bacteremia!)
I. Neisseria - Neisseria meningitidis (meningococcus)
6B. What is the clinical picture of Neisseria meningitidis (meningococcus)
I. Neisseria - Neisseria meningitidis (meningococcus)
6B. What are the early symptoms meningococcal meningitis?
- fever, stiff neck, strong headache, back pain, joint pain, vomiting, petechia or rush*, photophobia
- in case of neonates: high voice crying, refusal of food, difficulty in waking up
I. Neisseria - Neisseria meningitidis (meningococcus)
6C. What are the late symptoms meningococcal meningitis?
neurological signs, convulsion, decreased consciousness, extended skin lesions; coma, death
I. Neisseria - Neisseria meningitidis (meningococcus)
6D. What is the Outcome of N. meningitidis meningitis?
- Average lethality: 8-15%
- Survivors experience 10-20% long-term or irreversible disability:
- impaired hearing/ hearing loss
- neurological sequelae (focal neurological deficits, cognitive impairment, epilepsy)
- amputation of extremities (if necrotised)
I. Neisseria - Neisseria meningitidis (meningococcus)
6E. What are the risk groups of N. meningitidis meningitis?
- newborns (after finishing breast feeding)
- people at overcrowded places (e.g. military service, summer festivals)
I. Neisseria - Neisseria meningitidis (meningococcus)
6F1. How do we identify Neisseria meningitidis (meningococcus) in Laboratory?