Actinobacillus

Question 1

Actinobacillus - General description

Answer 1

Member of Family Pasturellaceae - Gram negative coccobacillis - “Morse Code” appearance - facultative anaerobe - Oxidase positive - Most urease positive - CAMP positive with Staph aureus - Cannot live in environment, need carriers for transmission

Question 2

Actinobacillus - Commensals

Answer 2

Upper respiratory & oral cavity - Opportunistic pathogens

Question 3

Actinobacillus - target cells

Answer 3

Nasal cavity & tonsillar crypts (of carrier animals) ; Terminal bronchioles & alveoli (of pre-diseased animals) - Causes Lower Respiratory Tract diesease

Question 4

Actinobacillus- Pathogenesis

Answer 4

Contamination–> Inflammatory response (LPS, Urease) –> Bacteria survives, colonize, replicates–> septicemia (capsule, OMP, RTX toxin) –> Full disease

Question 5

Actinobacillus - Clinical signs

Answer 5

Suppurative lung lesions - Granuloma formation in ruminant tongue & lymph nodes (Wooden Tongue*****)

Question 6

When I say Wooden Tongue, you say…

Answer 6

Actinobacillus! in ruminants (A. lignieresii)

Question 7

A. ligniersii - in ruminants

Answer 7

Wooden/Timber tongue!!! - Normal flora of nasopharynx - Introduced by trauma (plant) - May interfere with food intake –> weight loss–> dehydration

Question 8

Common confusion with A. ligniersii

Answer 8

Often confused with Lumpy Jaw (actinoMYCOSIS) - Actinomycosis in BONE / Actinobacillus in soft tissue

Question 9

Actinobacillus in rams

Answer 9

A. seminis - Epididymitis in young rams - Purulent discharges

Question 10

Actinobacillus in swine - causative species and disease patterns

Answer 10

A. pleuropneumoniae - A. suis - A. equuli - Pneumonia and septicemia of young pigs in cold months (crowding/poor ventilation)

Question 11

Actinobacillus in swine - Acute presentation

Answer 11

High mortality - Septicemia- skin lesions as in swine erysipelas

Question 12

Actinobacillus in horses

Answer 12

Pneumonia, mixed infections with Strept. equi - Septicemia - Sleepy Foal Disease - A. equuli, Navel Ill - good hygiene practices important

Question 13

What causes Sleepy Foal disease in equines?

Answer 13

A. equuli

Question 14

Wooden tongue pathology

Answer 14

A. ligniersii - Cell-mediated Hypersensitivity - ABs in colostrum for piglets & foals - Ab’s against RTX - Vaccine protects against homologous serotypes only - Eliminate carrier sows

Question 15

Actinobacillus Fastidious-ness

Answer 15

Growth on blood agar requires V factor (NAD-dependent**)

Question 16

Actinobacillus on MacConkey agar

Answer 16

Most grow, A. pleuropneumoniae doesn’t

Question 17

Actinobacillus Tx -

Answer 17

Antimicrobials - Iodides orally or IV for wooden tongue