18 – Actinobacillus Flashcards
1
Q
Microbiological characteristics
A
- Gram-negative rods or coccobacilli
- Facultative anaerobes
- Biocontainment level 2
- Some are fastidious and difficult to grow
- Presence of sulfur granules and pyogranulomatous inflammation seen with A. lignieresii
2
Q
Actinobachillus suis: pure culture microbial characteristics
A
- Pleomorphic ‘morse code’ morphology: combination of cocci and rods
3
Q
Natural host or habitat
A
- Host associated microbes
o A. pleuropneumoniae infections are contagious
o Others originate from animals endogenous organism - Found in upper respiratory tract and mouths of animals and people
- Found in GIT
- *do NOT survive well in environment
4
Q
NAD dependent (“V-factor”)
A
- Dependence can be detected with supplementation or co-culture with S. aureus which overproduce V-factor
- *only grow close to S. aureus growth
5
Q
Virulence factors of A. pleuropneumoniae
A
- Type 4 fimbriae: adhesion
- Capsule: anti-phagocytic
- Apx toxin
- RTX toxin
- Proteases
6
Q
Apx toxin
A
- Cytotoxin which is within the RTX superfamily of toxins
o Pore forming cytotoxins which affect porcine neutrophils
7
Q
RTX toxin
A
- Found in A. equuli
- Shown to be toxic to equine ganulocytes
8
Q
APP (A. pleuropneumoniae) in pigs
A
- Very important, economically damaging disease
- Spread between pigs through DROPLETS (requires close contact)
o Chronic, subclinical carriers maintain in herd
o Inflammation stimulates coughing=spread - Variable incubation period
- Outbreaks in 2-4month old piglets (wan of maternal immunity)
- Disease prevention varies with age, herd health state, environmental conditions
9
Q
APP peracute disease (pigs)
A
- High fever
- May have diarrhea/vomiting
- Fibrinous/necrotizing pneumonia and fibrinous pleuritis
- Respiratory disease followed by circulatory collapse
- Animals become cyanotic
- Mouth breathing shortly before death
- Death as quick as 4hrs (up to 36hrs)
10
Q
APP acute disease (pigs)
A
- More widespread in barn
- Inappetent, wont drink
- Respiratory signs (cough, mouth breathing)
- Respiratory and circulatory failure
- Can see spectrum of outcomes within herd (recovery -> death)
11
Q
APP chronic disease (pigs)
A
- Following resolution of acute signs or without prior acute disease
- Lethargy, exercise intolerance
o Fibrinous pneumonia - Decreased production even with antimicrobials
12
Q
Management/prevention of APP (pigs)
A
- Chronic/subclinical infections=persistent problems
- Transmits between herds by introduction of carries (AIAO)
- Buying replacement stock from specific pathogen free herds
- Maintaining a healthy herd (those with influenza=predisposed)
- Vaccination
13
Q
APP similar disease syndrome with A.suis, but other body systems also involved
A
- Sepsis
- Meningitis
- Abortion
14
Q
Actionbacillus lignieresii
A
- Normal member of oral and rumen microbiota
- Disease tends to be sporadic: when animals eat abrasive food
15
Q
Actinobacillus lignieresii: wooden tongue (cattle), signs
A
- Glossal actinobacillosis
- Animals salivate excessively (may have difficulty eating)
- Tongue=swollen and hard
- Painful
- May have nodules develop on tongue which typically contain purulent material (nodules may be ulcerated)
- *infections at other sites can occur
