Actinobacillus

• Actinobacillus is a small Gram-negative coccobacillus that may form filaments.
• Actinobacillus fermentative without gas.
• Some species of Actinobacillus grow on MacConkey agar.
• Colonies of Actinobacillus may be sticky.
• Some species of Actinobacillus are beta-hemolytic.
• Actinobacillus is an obligate parasite of mucosal surfaces.
• Some species of Actinobacillus are host-specific.
• Alignieresii, Apleuropneumoniae, Auis Equuli Subsp Equuli Subsp Haemolyticus are major species and hosts of Actinobacillus.
• A. actinomycetemcomitans causes periodontal disease and endocarditis.
• A. capsulatus causes arthritis and bacteremia.
• “A. seminis” causes epididymitis and orchitis.
• A 1,200-sow farrow-to-finish swine herd had a persistent problem with respiratory disease in growing and finishing pigs.
• Clinical signs of respiratory disease in pigs vary from sudden death to chronic pneumonia with weight loss and slow growth.
• The overall mortality rate for growing and finishing pigs on the farm varies from 0.37% to 0.84% per month from July 1990 to February 1991, and mortality due to respiratory disease varies from 0.17% to 0.52% per month for the same period.
• Pigs with clinical signs of respiratory disease had variable responses to intramuscular procaine penicillin G.
• Equuli and Suis are bacteria that can also be isolated on MacConkey agar.
• A lignieresii requires blood and CO2 for growth and may have granules present.
• Most strains of Apleuropneumoniae require V factor for growth and can be isolated on chocolate agar or blood and staph streak.
• Alignieresii is a bacteria that causes wooden tongue, characterized by granulomatous lesions and granules.
• Clinical diseases associated with A lignieresii include wooden tongue, characterized by granulomatous lesions and granules.
• Clinical diseases associated with Apleuropneumoniae include pleuropneumonia, characterized by hemorrhagic lesions.
• Transmission of these bacteria occurs when pigs are very young, and stress and previous infection predispose older animals to infection.
• Clinical diseases associated with A equuli include foal septicemia, characterized by aneurysms and systemic infections.
• Pleuropneumoniae is a bacteria that causes pleuropneumonia, characterized by hemorrhagic lesions.
• Ceftiofur, gentamycin, and trimethoprim/sulfadiazine are effective in treating these bacteria if diagnosis is made early enough.
• A equuli and A suis can also be isolated on MacConkey agar.
• Antibodies to RTX toxins provide immunity against these bacteria.
• Passive protection of piglets from colostrum provides immunity against these bacteria.
• Vaccines for these bacteria are not common, but live, attenuated vaccines should work best and are not available.
• Clinical diseases associated with A suis include swine neonatal septicemia, characterized by petechiae and edema, and pneumonia in adults.
• These bacteria need to be isolated in pure culture or predominance because they can be normal flora.
• The herd had a recurrent problem with swine influenza in nursing and recently weaned pigs, but no associated deaths or significant effect on rate of gain was noted.
• Gross lesions of diseased pigs vary from multifocal mottled tan to dark red raised areas in both cranial and caudal lung lobes to extensive necrosis of caudal lobes with many fibrinous and fibrous adhesions to the thoracic wall.
• Haemolytic uraemic syndrome is primarily associated with stress in adult horses, causing sleepy foal disease.
• Actinobacillus equuli is primarily associated with animals and animal diseases, especially septicemia in foals.
• Actinobacillus equuli has been isolated from human wounds following horse bites.
• Abortion, stillborn fetus, metritis, mastitis, meningitis, respiratory disease, wound infections, bacteremia, arthritis, endocarditis, and inflamed wounds are other diseases caused by Actinobacillus equuli.
• Immunity to Actinobacillus equuli can be provided by vaccination of mares, but this is not commercially available.
• Prebreeding culture screening may be more effective at prevention of Actinobacillus equuli infections.
• Attempts at passive immunity with antiserum have not worked against Actinobacillus equuli.