Unit 2- Actinobacillus Flashcards
Actinobacillus
Gram negative coccobacillus, filamentous, fermentative without gas, some grow on macconkey, sticky colonies, beta hemolysis, obligate mucosal parasites
Actinobacillus pleuropneumoniae
Pig specific, biovar 1 requires V factor from chocolate agar, hemolytic
V Factor
NAD
Swine Pleropneumonia
A pleropneumoniae, fibrinous pleuritis and pneumonia, hemorrhagic necrotic lesions, minor lesions, chronic infection carries disease to nonimmune herds
Swine Pleuropneumoniae Clincal Signs
Trembling, anorexia, fever, dyspnea, hemorrhage, chonic carrier
A pleuropneumoniae Virulence
Capsule, LPS, RTX toxins, adhesins
RTX Toxins
Cause hemorrhagic and necrotic lesions by lysing red and white blood cells
A pleuropneumoniae Compomising Factors
Some serotypes highly virulent, stress and overcrowding
A pleuropneumoniae Immunity
Neutralizing antibodies to RTX, other antibodies enhance opsonization and clearance
A pleuropneumoniae Vaccines
Live attenuated to induce neutralizing antibodies
Actinobacillus equuli subsp equuli
Tonsils, intestine, and respiratory tract of horse and pig, can rarely infect other species, grows on macconkey, nonhemolytic, RTX toxin
Sleepy Foal Disease
A equuli subsp equuli causes acute bacteremia, can lead to aneurism if coinfected with strongylus vulgaris
Actinobacillus equuli subsp haemolyticus
Infects horse respiratory, less common, hemolytic, RTX toxin
A equuli subsp haemolyticus Disease
Adult abortion, metritis, mastitis, meningitis, respiratory disease, wound infection, adn endocarditis, sometimes sleepy foal disease
A equuli Virulence
LPS, adherence factors, weak RTX tocin
A equuli Compromising Factors
Mares carrying prior to delivery, stress, parasitism
A equuli Immunity
Sanitation to birthing environment, maternal colostrum, prebreeding culture screening
Actiobacullus lignieresii
Cattle and sheep but zoonotic, oral commensal, requires serum or blood and CO2 for isolation
Wooden Tongue
A lignieresii causes tumor like lesions of tongue and oral cavity that ulcerate following trauma, may cause granules
A lignieresii Virulence
LPS, weak RTX toxin, dissemination, resistance to host defenses
A lignieresii Compromising Factors
Normal flora, self innoculation of buccal epithelium following trauma
A lignieresii Immunity
Cellular Th1 immunity, granulomatous reaction common
A lignieresii Treatment
Sodium/potassium iodide on local lesions
Actinobacillus suis
Swine mucosal surfaces, sticky on MacConkey, hemolytic
A suis Disease
Bacteremia in piglets, endocarditis, pericarditis, edema, petechiae, fever, respiratory distress, localized lesions in adults
A suis Virulence
RTX toxin, capsule, LPS, adhesions
A suis Transmission
Carried in respiratory tract and tonsils, transmission at young age
A suis Treatment
Confirm AMR with susceptibility test
Diagnosis
Pure culture
A pleuropneumoniae Diagnosis
Requires V factor for growth, chocolate or blood and staph streak agar required
A lignieresii Diagnosis
Requires blood and CO2, granules present
A equuli Diagnosis
MacConkey
