FUSOBACTERIUM

Question 1

Biovar A and B induces what ds.?

Answer 1

Bovine liver abscesses

Question 2

B. fragilis comprises how many species?

Answer 2

10 species

Question 3

Biovar C is also known as ?

Answer 3

F. pseudonecrophorum now F. varium: infrequent opportunist in humans

Question 4

Give the diseases induced by F. necrophorum in cattle.

Answer 4

• 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

Question 5

What are the 4 biotypes or biovars of F. necrophorum?

Answer 5

1. A
2. B
3. AB
4. C

Question 6

Give the diseases induced by F. necrophorum in sheep.

Answer 6

• 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

Question 7

Give the diseases induced by F. necrophorum in fowl.

Answer 7

• Involved in avian diphtheria, primary cause is fowl pox virus

Question 8

B. fragilis produces endotoxin causing ?

Answer 8

Accumulation of fluid in ligated intestinal loops of lambs and calves

Question 9

Give the name of the enterotoxin produced by B. fragilis and give its induced diseases.

Answer 9

• Fragilysin - an extracellular zinc metalloprotease
• Cause of diarrheal diseases in calves, lambs, foals, piglets and humans

Question 10

What are the virulence factors of B. nodosus?

Answer 10

• Endotoxin and a potent leukotoxin
• Extracellular products such as hemolysin, hemagglutinin, adhesin, platelet aggregation factor, protease, DNAse

Question 11

F. necrophorum is usually a secondary invader in what diseases?

Answer 11

• Necrotic stomatitis
• Pharyngitis
• Enteritis
  *** Most commonly in swine

Question 12

Between the 4 biovars, which is rarely isolated from animals?

Answer 12

AB - pathogenicity intermediate between A and B

Question 13

Biovar B is designated as?

Answer 13

F. necrophorum subsp. funduliforme

Question 14

Give the pathogenesis of F. necrophorum.

Answer 14

• 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

Question 15

F. necrophorum is commensal of ?

Answer 15

• Alimentary tract
• Mucous membranes

Question 16

Vaccination is not successful for F. necrophorum. True or False?

Answer 16

True

Question 17

What is the general term for F. necrophorum infection?

Answer 17

Necrobacillosis

Question 18

Describe the colonies of F. necrophorum.

Answer 18

• Colonies are small, smooth, convex and whitish yellow in color with narrow zone of alpha or beta hemolysis

Question 19

Biovar A is designated as?

Answer 19

F. necrophorum subsp. necrophorum

Question 20

Give the diseases induced by F. necrophorum in swine.

Answer 20

• Principal cause of “bull nose” from injury caused by ringing boars

Question 21

This antimicrobial agent is most effective as food additive in treating F. necrophorum infection.

Answer 21

Tylosin

Question 22

Biovar B is more virulent than A. True or False?

Answer 22

False

Question 23

Biovar B can be isolated from ?

Answer 23

Ruminal contents and lesions

Question 24

What is the primary media for F. necrophorum?

Answer 24

• Hemin with menadione, blood agar, selective media to suppress facultative anaerobes and bile esculin agar

Question 25

Give the diseases induced by F. necrophorum in **horse**.

Answer 25

* Thrush, involving frog of hoof * Pneumonia and septicemia

Question 26

Describe the morphology of F. necrophorum.

Answer 26

* Gram negative rods, initially pleomorphic: short rods, long filaments and moniliform bodies seen