ACTINOBACILLUS Flashcards
Pathogenesis is not included. Please refer on the reference materials.
Give the diagnostic methods for A. seminis.
- Difficult to identify due to its lack of biochemical activity
- Differentiation from B. ovis is based on morphology and modified Ziehl-Neelsen staining technique (mZ-N)
- Does not stain red in mZ-N staining technique
- Immunofluorescence technique used for diagnosis of epididymitis
Identify the Actinobacillus sp. with the given data:
- Best grown on media enriched with blood or serum and incubated in an atmosphere of 20% CO2
- On 5% horse-blood tryptose agar: colonies are pinpoint to drop-like @ 24hrs; becomes enlarged and umbonate with transparent periphery and grayish center
- Non-hemolytic
- Does not grow on MAC
- Does not ferment CHO
- Does not produce catalase
- Does not reduce nitrates
- Produces **slight amounts of H2S **
- Negative results in: Oxidase, MRVP, indole, phosphatase, gelatinase, and Citrate utilization
A. seminis
Actinobacillus ferments CHO. True or False?
True
Actinobacillus produces indole. True or False?
False, only B-galactosidae
Give the diagnostic methods for A. lignieresii.
- Gram-stained smears of sulfur granules reveal club-bearing rosettes containing masses of
- Gram-negative rods and cocci
Actinobacillus can reduce nitrates to nitrites. True or False?
True
Give the morphology of Actinobacillus spp.
- Gram-negative
- Non-motile
- Non-spore forming **rods or coccobacili
- Pleomorphic
Give the diagnostic methods for A. pleuropneumoniae.
- Isolation on BAP
- Requirement for V factor
- presence of B-hemolysin
Classify Actinobacillus based on their O2 requirement.
Facultatively anaerobic
Identify the Actinobacillus sp. with the given data:
- Rod-shaped cells encased in small cheese-like granules in the pus of lesions
- Similar to “sulfur granules” of actinomycosis, but generally smaller
- Morphology depends on medium used:
—- Fluid cultures: Diplococci and slender rods
—- Solid media: Long curved forms in colonies - Serophilic, little growth in most media unless serum or blood is present
- Rather strongly aerobic
- Primary cultures best grow when incubated in an atmosphere with 10% CO2
- In Serum agar: delicate nail-like growths along the length of stab made; surface colonies are bluish white
- Smooth, glistening, and convex
- Does not liquefy the medium
- Ferments: glucose, lactose, sucrose, maltose, raffinose, and mannitol
- Irregularly ferments xylose
- Produces indole in small amounts
A. lignieresii
Actinobacillus is urease positive. True or False?
True
Identify the Actinobacillus sp. with the given data:
- Grows rapidly on BAP and other enriched media
- Colonies are mucid and iridescent; 1-2 mm in diameter
- Produces a zone of Beta-hemolysis on sheep/calf-blood; enhanced by beta-toxin of S. aureus
- Hemolysin is extracellular
A. pleuropneumoniae
This species causes actinobacillosis in cattle and sheep.
A. lignieresii
Give the diagnostic methods for A. equuli.
- Blood, kidney lesions, synovial fluids, and cervical swabs from mares cultured on BAP
This species causes foal septicemia.
A. equuli
This species causes pneumonia in calves and seminal vesiculitis in bulls.
A. actinoides
Give the immunities from A. lignieresii infection.
- Many normal cattle have specific agglutinins in their serum
- There maybe significant rise in the titer serum from affected cows
- Cell-mediated immunity is important due to granulomatous nature of lesions
- Formalinized bacterin reduces number of animals that relapse and prevents the occurrence of new cases.
This species causes arthritis in rabbits.
A. capsulatus
This species causes salpingitis and peritonitis in chickens.
A. salpingitidis
This species causes septicemia and other infectious processes in pigs.
A. suis
Give the immunities from A. suis infection.
- No commercial vaccine available
Identify the Actinobacillus sp. with the given data:
- Colonies are moderately sticky and may adhere to agar surface
- In serum broth: produces viscous growth
- On horse-blood agar: narrow zones of alpha hemolysis
- On sheep-blood agar: wide zones of beta hemolysis
- May produce H2s
- Does not produce indole or urease
- Produces acid when grown with glucose, lactose, arabinose, mannitol, or salicin
- Hydrolyzes esculin
A. suis
Give the diagnostic methods for A. suis.
- Specimens from tissues obtained at necropsy must be cultured on BAP and MAC; incubate at 37 °C for 1-3 days
- Sticky, hemolytic colonies
- Pink, lactose-fermenting colonies on MAC
Give the immunities from A. seminis infection.
- Little is known about immune response
- Complement-fixing abs is present in serum
- Complement fixation detects about 75% of infected flocks
