BACTEROIDES

Question 1

Gram negative anaerobic non-sporeforming bacilli:

B. melaninogenic has been renamed as?

Answer 1

Prevotella mellaninogenica (affects animals)

Question 2

B. nodosus can’t ferment CHO. True or False?

Answer 2

True

Question 3

Gram negative anaerobic non-sporeforming bacilli:

B. levii has been renamed as? Give the associated infections.

Answer 3

Porphyromonas levii - associated with summer mastitis in cattle

Question 4

What are the antigens present in B. nodosus?

Answer 4

• K (specific)
• O (group): heat-stable

Question 5

Describe the morphology of B. nodosus.

Answer 5

• Large, piliated, rod-shaped; rods are straight but may be slightly curved
• Non-motile, non-spore forming

Question 6

B. nodosus is grown best at what temp and media?

Answer 6

• ** 37 C; neutral or alkaline media containing trypticase and arginine (0.05)**
• Growth is also enhanced by adding 10% horse serum

Question 7

Describe the colonies of B. nodosus.

Answer 7

• Smooth, convex, and semi-opaque or translucent
• Virulent isolated from animals with foot-rot produce papillate or beaded colonies that etch the medium
• Less virulent isolated produce mucoid colonies

Question 8

B. nodosus is an obligate parasite of the hooves of ?

Answer 8

• Sheep
• Goats
• Cattle

Question 9

Gram negative anaerobic non-sporeforming bacilli:

B. corrodens has been renamed as ?

Answer 9

Eikenella corrodens (affects humans and animals)

Question 10

Gram negative anaerobic non-sporeforming bacilli:

B. nodosus has been renamed as? Give the associated infections.

Answer 10

Dichelobacter nodosus - contagious foot rot in sheep

Question 11

What specie of Bacteroides has enterotoxin-like activity and has been isolated from outbreaks of acute diarrheal disease in lambs?

Answer 11

B. fragilis

Question 12

What are the common clinical signs induced by Bacteroides ?

Answer 12

Abscesses, necrotic, and suppurative processes

Question 13

In old cultures, B. nodosus forms ?

Answer 13

Tyrosine crystals

Question 14

B. nodosus is sensitive to what microbial agents?

Answer 14

Penicillin
Tetracycline
Chloramphenicol
Clindamycin
Cefamandole

Question 15

What are the immunity methods against B. nodosus?

Answer 15

• IgG1 abs - acts on fimbrial (K) antigen
• Vaccination

Question 16

B. nodosus has numerous pili. True or False?

Answer 16

False

Question 17

B. nodosus is an essential transmitting agent of what disease in sheep?

Answer 17

Foot rot

Question 18

Gram negative anaerobic non-sporeforming bacilli:

B. heparinolyticus has been renamed as? Give the associated infections.

Answer 18

Prevotella heparinolyticus - oral infections in horses and cats

Question 19

The K antigen is associated with ?

Answer 19

Fimbriae (pili)

Question 20

What are the diagnostic methods for B. nodosus?

Answer 20

• Smears prepared from the edge of lesions beneath the epidermal matrix and stained with Gram’s stain
• Eugon agar, 0.2% yeast extract, 10% horse blood, and 1 μg of lincomycin per milliliter

Question 21

When B. nodosus is stained with methylene blue, they often show?

Answer 21

One or more several metachromatic granules

Question 22

O antigen LPS is biologically, chemically, and ultrastructurally similar to ______ and consists of a polysaccharide joined with lipid A through acid-labile 2-keto-3-deoxyoctonic acid link

Answer 22

Enterobacteriaceae

Question 23

What are the other names of B. nodosus?

Answer 23

• Actinomyces nodosus
• Fusiformis nodosus
• Ristella nodosa

Question 24

Describe B. nodosus acc. to its O2 requirement.

Answer 24

Obligate anaerobe

Question 25

What is the only specie of Bacteroides that holds veterinary importance particularly affecting domestic animals?

Answer 25

B. nodosus

Question 26

Bacteroides spp. are classified into three non-sporeforming groups. What are these?

Answer 26

1. Gram negative bacilli (90%) 2. Gram positive cocci 3. Gram positive bacilli