Actinobacillus Flashcards
Characteristics
-gram negative rods or coccibacilli
-facultative anaerobes
-biocontainment level 2
-some hard to grow
A. lignieresii pathogenesis
Presence of sulfur granules and pyogranulomatous inflammation
Actinobacillus suis morphology
-pleomorphic
-morse code morphology
Host and habitat
1.Host associated microbes
-A pleuropneumoniae infections are contagious
2.Upper respiratory tract and mouths of animals and people
3.GI tract
**not in environment
Factor V or NAD
-produced by staphylococcus aureus
-Needed for A. pleuropneumoniae
**nutritionally dependent
Therefore A. pleuropneumoniae only growing nearby S. aureus
Virulence factors of A. pleuropneumoniae
1.Type 4 fimbriae- adhesion
- Capsule- anti-phagocytic
- Apx toxin- pore forming cytotoxins affecting porcine neutrophils
- RTX toxin- toxic to equine granulocytes
- Proteases- breakdown of host cell proteins
A. pleuropneumoniae (APP) in pigs
-economically damaging disease
-spread through droplets (require close contact). Chronic and subclinical carriers maintain it in herd.
-inflammation leads to coughing and further spread
-variable incubation period; outbreaks in 2-4mth old pigs due to waning maternal immunity
-causes pleuropneumonia
*varies in presentation with age, health, environment
Peracute APP disease
-high fever, diarrhea, vomiting
-fibrinous/necrotizing pneumonia and fibrinous pleuritis
-respiratory distress followed by circulatory collapse
-animals become cyanotic
**mouth breathing shortly before death (4 hrs to 36 hrs)
Acute APP disease
-more widespread in barn
-inappetent, wont drink, respiratory signs (mouth breathing coughing), respiratory and circulatory failure
-various outcome in herd (recovery and death)
Chronic APP disease
-follows resolution of acute signs or without prior acute disease
-lethargy, exercise intolerance (fibrinous pneumonia
**decreased production rates even with antimicrobials
APP management/prevention
-Chronic/subclinical- a persistent problem on affected farms
-Use all in all out to prevent herd transmission
-buying replacement stock from specific pathogen free herds
-maintain healthy herd to avoid predisposed influenza pigs
-vaccines
Differential diagnosis for APP
-A. suis
**but it will also affect other systems (sepsis, meningitis, abortion)
A. suis in pigs
-opportunistic pathogen that affects high health farms
*difficult to differentiate from A. equuli phenotypically
-causes septicemia and arthritis in piglets; pleuropneumoniae, meningitis, abortion in adults
A. lignieresii in cattle
-normal pathogen of oral and rumen microbiota
-disease sporadic occurring from animals eating abrasive feed. Management= avoid abrasive food
-causes wooden tongue (glossal actinobacillosis)
Wooden tongue
-animals salivate excessively
-difficulty eating
-painful
-nodules on tongue can develop into purulent material and can be ulcerated
-infections at other sites (lymph nodes, cranial nerves)
