Gut ecology

Question 1

What are the facultative and anaerobes in normal microflora?

Answer 1

Facultatives = streptococci, lactobacilli, staphylococci, corynebacteria
Anaerobes = bacteroides

Question 2

What are the 3 conditions which can arise due to dental plaque ?

Answer 2

caries
gingivitis
periodontitis

Question 3

What is the first acquired of the flora after birth ?

Answer 3

Sterile when born
Hours after = streptococcus species
Acquisition of flora depends on exposure at the time of birth, caesarean or vaginal

Question 4

What bacteria colonises on teeth?

Answer 4

Streptococcus mutans and streptococcus sanguis on teeth and in gingiva and adhere

Question 5

Describe the acquisition of oral flora after the emergence of he babies firth teeth

Answer 5

• Organiams which favour hard surfaces intro e.g strep.sanguis and strep.mutans, actinomyces
• colonisation of crevicular tissues
• prosthetic appliances (dentures) may harbour yeast biofilm

Question 6

What species are found in the gingivitis?

Answer 6

spirochetes and fusiform bacilli

Question 7

What are the species found in the periodontitis?

Answer 7

Treponema denticola,
Porphyromonas gingivitis
Aggregatibacter actinmycetemcomitans

Question 8

What are the types of cell-cell communication between the microflora?

Answer 8

• intraspecies
• interspecies
• mediated by DPD / AI-2

Question 9

What causes stomach ulcers and stomach cancer?

Answer 9

Helicobacter pylori penetrates mucin lining produces urease to neutralise acid pH

Question 10

What is vacillating cytotoxin A (VAC A)?

Answer 10

toxin produced by Helicobacter pylori
Kills cells in the lining of the stomach
Bacteria get more nutrients as it decreases the competition from the stomach lining cells

Question 11

What is the shift which take place at weaning ?

Answer 11

from predominantly facultative anaerobic species (E.coli) to obligate anaerobic species