Category:Actinobacillus species

Mainly pathogens of farm animals
Commensals of mucosa of upper respiratory tract and oral cavity
Cannot survive long in the environment, therefore carrier animals are important in their transmission
Cause granulomatous inflammation

Commensal of the equine intestinal and reproductive tract
Pathogenesis and clinical signs:
- Foals infected in utero or or after birth via the umbilicus
- Infection at birth causes severe enteritis and septicaemia within 24 hours, known as sleepy foal disease
- Foals become pyrexic and recumbent
- Death usually occurs within 1-2 days
- In foals that survive neonatal infection the condition progresses to cause joint infections and purulent nephritis, enteritis or pneumonia
- A. equuli in arthritis of horses
- Abortion, septicaemia and peritonitis in horses
Diagnosis:
- Specimens cultured on blood agar and MacConkey agar and incubated aerobically for 1-3 days
- Sticky colonies with variable haemolysis on blood agar
- Lactose-fermenting colonies on MacConkey agar
Treatment and control:
- Antimicrobials ineffective unless early in course of disease
- Blood trasfusion and administration of colostrum
- Good hygiene
- Consider prophylactic antibiotics for new-born foals
- Bacteria susceptible to streptomycin, tetracyclines and ampicillin
In other animals:
- Septicaemia in piglets
- Arthritis and enteritis in pigs
- Enteritis in calves
- RTX group cytotoxin present

May be present in upper respiratory tract of sows
Pathogenicity and clinical signs:
- Infection of piglets via aerosol or possibly skin abrasions
- Fatal septicaemia in piglets 1-8 weeks old
- Mortality up to 50% in some litters
- Fever, respiratory distress, prostration and paddling of forelimbs seen in piglets
- Petechial and ecchymotic haemorrhages in many organs
- Interstitial pneumonia, pleuritis, meningoencephalitis, myocarditis and arthritis
- Causes abscesses in joints and lungs of older pigs
- Carried in the nasopharynx of pigs and nose of horses
- Carriage may confer immunity to the more severe pleuropneumonia
Diagnosis:
- Specimens cultured on blood agar and MacConkey agar for 1-3 days
- Sticky haemolytic colonies
- Pink, lactose-fermenting colonies on MacConkey agar
Treatment and control:
- Bacteria usually susceptible to ampicillin, carbenicillin, potentiated sulphonamides and tetracyclines
- Disinfect contaminated pens
Other animals:
- Septicaemia and pneumonia in foals
- Pneumonia in pigs and horses

Epididymitis in young rams (4-8 months)
Polyarthritis in lambs
Organism found in prepuce
Opportunistic infection causing abscesses in epididymides
May be purulent discharge onto scrotal skin
Specimens cultured on blood agar and incubated aerobically for 1-3 days produce pin-point haemolytic colonies which are catalase-positive; no growth on MacConkey agar

Pages in category "Actinobacillus species"

The following 6 pages are in this category, out of 6 total.