FUSOBACTERIUM Flashcards
Biovar A and B induces what ds.?
Bovine liver abscesses
B. fragilis comprises how many species?
10 species
Biovar C is also known as ?
F. pseudonecrophorum now F. varium: infrequent opportunist in humans
Give the diseases induced by F. necrophorum in cattle.
- Metritis, cellulitis, mastitis and calf diphtheria
- Found in necrotic areas of the mouth, pharynx, and trachea; necrotic laryngitis in feeder cattle
- Primary cause of liver abscesses and foot rot
What are the 4 biotypes or biovars of F. necrophorum?
- A
- B
- AB
- C
Give the diseases induced by F. necrophorum in sheep.
- Frequent 2ndary invader in lip and leg ulcerations (primary cause is ulcerative dermatosis virus)
- Together with Archanobacterium pyogenes (now Truepella pyogenes), causes foot abscesses or ovine interdigital dermatitis, abortion
Give the diseases induced by F. necrophorum in fowl.
- Involved in avian diphtheria, primary cause is fowl pox virus
B. fragilis produces endotoxin causing ?
Accumulation of fluid in ligated intestinal loops of lambs and calves
Give the name of the enterotoxin produced by B. fragilis and give its induced diseases.
- Fragilysin - an extracellular zinc metalloprotease
- Cause of diarrheal diseases in calves, lambs, foals, piglets and humans
What are the virulence factors of B. nodosus?
- Endotoxin and a potent leukotoxin
- Extracellular products such as hemolysin, hemagglutinin, adhesin, platelet aggregation factor, protease, DNAse
F. necrophorum is usually a secondary invader in what diseases?
- Necrotic stomatitis
- Pharyngitis
- Enteritis
*** Most commonly in swine
Between the 4 biovars, which is rarely isolated from animals?
AB - pathogenicity intermediate between A and B
Biovar B is designated as?
F. necrophorum subsp. funduliforme
Give the pathogenesis of F. necrophorum.
- Invades and multiplies in anaerobic environment provided by damaged tissues
- Frequently a secondary bacterial invader
- Infections characterized by necrotic process that are frequently mixed such as liver abscesses in cattle with Archanobacterium pyogenes
F. necrophorum is commensal of ?
- Alimentary tract
- Mucous membranes
Vaccination is not successful for F. necrophorum. True or False?
True
What is the general term for F. necrophorum infection?
Necrobacillosis
Describe the colonies of F. necrophorum.
- Colonies are small, smooth, convex and whitish yellow in color with narrow zone of alpha or beta hemolysis
Biovar A is designated as?
F. necrophorum subsp. necrophorum
Give the diseases induced by F. necrophorum in swine.
- Principal cause of “bull nose” from injury caused by ringing boars
This antimicrobial agent is most effective as food additive in treating F. necrophorum infection.
Tylosin
Biovar B is more virulent than A. True or False?
False
Biovar B can be isolated from ?
Ruminal contents and lesions
What is the primary media for F. necrophorum?
- Hemin with menadione, blood agar, selective media to suppress facultative anaerobes and bile esculin agar
Give the diseases induced by F. necrophorum in horse.
- Thrush, involving frog of hoof
- Pneumonia and septicemia
Describe the morphology of F. necrophorum.
- Gram negative rods, initially pleomorphic: short rods, long filaments and moniliform bodies seen
