II-A. Systemic bacteriology | 16. Haemophilus, Legionella, Bordetella Flashcards
I. Haemophilus genus
1. What is the morphology of Haemophilus genus?
Gram-negative coccobacilli
I. Haemophilus genus
2. What are the important species of Haemophilus genus?
- H. influenzae (H. influenzae (type B))
- H. parainfluenzae
- H. ducreyi
- H. haemolyticus (see later, at HACEK-group)
I. Haemophilus genus - Haemophilus influenzae
3. What are the features of Haemophilus influenzae?
fastidious bacterium
- requires factor X and V for growth (hem and NAD)
I. Haemophilus genus - Haemophilus influenzae
4. What are the virulence factors of Haemophilus influenzae? (CAI)
- capsule (A-F serotypes)
- B-capsule serotype is the most important
- usually causes invasive infections - adhesive pili
- IgA-protease (neutralizes mucosal immunity)
I. Haemophilus genus - Haemophilus influenzae
5. What are the diseases caused by Haemophilus influenzae?
- otitis media, sinusitis
- bronchitis, laryngitis, pneumonia
- blood stream infection, meningitis
I. Haemophilus genus - Haemophilus influenzae
6. How do we diagnose Haemophilus influenzae?
- based on clinical signs and symptoms
- sampling: based on the clinical disease
- laboratory: culturing
I. Haemophilus genus - Haemophilus influenzae
7. How do we cultivate Haemophilus influenzae for diagnosis?
laboratory: culturing
* on factor X and factor V supplemented chocolate agar
* satellitism on blood agar
I. Haemophilus genus - Haemophilus influenzae
8. What is empirical therapy for Haemophilus influenzae?
- beta-lactamase production might occur
- amoxicillin-clavulanic acid, or cephalosporins ( for e.g. ceftriaxon)
I. Haemophilus genus - Haemophilus influenzae
9. What is prevention for Haemophilus influenzae?
MANDATORY B-serotype polysaccharide capsule vaccine (Hib) for the
prevention of invasive diseases
I. Haemophilus genus
10. What are the features of H. parainfluenzae?
- only requires factor V for growth (NAD)
- less virulent than H. influenzae, otherwise disease are similar
- might cause endocarditis, prostatitis / orchitis as well!
I. Haemophilus genus
11. What are the features of Haemophilus ducreyi?
- only requires factor X for growth (hem)
- sexually transmitted infection (STI)
+) soft, painful ulceration (chancroid)
II. Legionella genus
1 What is the important species of Legionella genus?
- Legionella pneumophila
II. Legionella genus
2. What are the features of Legionella pneumophila?
- most important species→ famous case: Philadelphia, 1976
- Gram-negative short rods or coccobacilli, form filaments
II. Legionella genus
3. What is the source of infection of Legionella pneumophila?
environment (rivers, ponds, humidifier, shower, AC)
II. Legionella genus
4. What is the transmission route of Legionella pneumophila?
via aerosols
II. Legionella genus
5. What are the virulence factors of Legionella pneumophila?
- haemolysin
- listeria-coagulase
- endotoxin (LPS)
II. Legionella genus
6. What are the diseases caused by Legionella pneumophila?
- mild form: Pontiac-fever
- fever, muscle ache, headache, → AB therapy is not necessary - severe form: legionellosis
- atypical pneumonia, fever, confusion, kidney failure
- high mortality (15-30%)
II. Legionella genus
7. How do we diagnose Legionella pneumophila?
- based on clinical signs and symptoms
- imaging (chest X-ray)
- Sampling
- laboratory