IIA. Systemic Bacteriology | 6. Actinomyces, Bifidobacterium, Eubacterium.

Question 1

I. Eubacterium
1. Give a summary of Eubacterium

Answer 1

1. G +, anaerobe
2. present in oral cavity, plaque
3. Periodontal disease
4. Amoxicillin

Question 2

I. Eubacterium
2. Describe morphology of Eubacterium?

Answer 2

• pleomorphic, Gram-variable rods or filaments
• Gram-positive bacilli

Question 3

I. Eubacterium
3. Site of infections of Eubacterium

Answer 3

main intraoral sites and infections: plaque biofilms and calculus; implicated in caries and periodontal disease

Question 4

I. Eubacterium
4. Give an example of Eubacterium

Answer 4

• E. yurii is involved in ‘corn-cob‘ formation in dental plaque
• Eubacterium Lentum has been linked to endocarditis

Question 5

II. Actinomyces
1. What are the features of Actinomyces?

Answer 5

• non-acid-fast, Gram-positive bacterium
• is anaerobic

Question 6

II. Actinomyces
2. Where are Actinomyces found?

Answer 6

found as a commensal organism in dental plaque and female genital tract

Question 7

II. Actinomyces
3. How do Actinomyces infect?

Answer 7

1. causes granulation tissues
2. form sinus tracts to the surface
   -> exudate from these sinus tracts contains hard microcolonies called sulphur granules

Question 8

II. Actinomyces
4A. What are the diseases caused by Actinomyces?

Answer 8

Question 9

II. Actinomyces
4B. What is the feature of cervicofacial actinomycosis?

Answer 9

cervicofacial actinomycosis (lumpy jaw)
=> after dental work is performed

Question 10

II. Actinomyces
4B. What is the feature of thoracic actinomycosis?

Answer 10

lung and ribs

Question 11

II. Actinomyces
4C. What is the feature of abdominal actinomycosis?

Answer 11

starts in the ileocecal region and frequently produces sinus tract to the skin surface

Question 12

II. Actinomyces
4D. What is the feature of mycetoma?

Answer 12

mycetoma
-> infection of the limb

Question 13

II. Actinomyces
4D. What is the feature of abdominal actinomycosis?

Answer 13

mycetoma
-> infection of the limb

Question 14

II. Actinomyces
5. What is the treatment for Actinomyces

Answer 14

• surgical drainage of necrotic tissues
• penicillin

Question 15

II. Actinomyces
6. Explain Actinomyces based on this picture

Answer 15

Question 16

III. Bifidobacterium
1. What are the features of Bifidobacterium?

Answer 16

8 species : B. dentium

Question 17

III. Bifidobacterium
2. What is the morphology of Bifidobacterium?

Answer 17

Morphology: G+ rods, filamentous form

Question 18

III. Bifidobacterium
3. How should we culture Bifidobacterium?

Answer 18

Culture: blood agar, anaerobic

Question 19

III. Bifidobacterium
4. Where can we find Bifidobacterium?

Answer 19

Normal flora in oral cavity, intestinal tract of babies

Question 20

III. Bifidobacterium
5. What are the diseases and probiotics for Bifidobacterium

Answer 20

• Probiotics – help perform normal function i.e. digestion and ward off pathogenic microbes
• Disease: caries? Periodontitis? pathogen in immunosuppressed state