Ch. 34 - The Family Pasteurellaceae

Question 0

Haemophilus virulence

Answer 0

Anti-phagocytic polysaccharide capsule (PRP ribose phosphate ribitol latex agglutination)

IgA proteases (colonization)

Question 1

Haemophilus

Answer 1

Small, pleomorphic G-cb

Colonize mucus membranes
Fastidious (X and V factors)

Lipid A endotoxin

Specific outer membrane proteins (diff. strains)

6 serotypes a-f (polysaccharide capsule)

8 biotypes I-VIII (biochemical testing)

3 spp.: H. influenzae, H. aegyptius, H. ducreyi

Question 2

Haemophilus influenzae B disease

Answer 2

Meningitis (Hib)

Epiglottitis (ped)

Cellulitis (ped)

Arthritis (ped)

Otitis, sinus, lower resp (non-encapsulated H. flu I and II)

Conjunctivitis (H. aegyptius)

Chancroid (H. ducreyi)

Question 3

Aggregatibacter

Answer 3

Small G-b
Facultative

Colonize human mouth, spread to blood (endocarditis)

A. actinomycetemcomitans
A. aprophilus

Treat with cephalosporin

Question 4

Actinobacillus

Answer 4

Colonize oropharynx

Rare cause of periodontitis, bacteremia, endocarditis, bite and wound

A. equuli
A. hominis
A. lignieresi
A. urease

Question 5

Pasteurella

Answer 5

Small G-b

Facultative

Fermentative

Oropharynx in healthy animals
Animal bites and scratches

Localized cellulitis & lymphadenitis, resp (in resp. comp.), systemic (immunoconpromised)

Human pathogens:

P. Multocida (SBA, CHOC, poor MAC & G- sel. Indole +)

P. canis