Microbiology of the Gastrointestinal Tract Flashcards Preview

ESA 3 - Gastrointestinal System > Microbiology of the Gastrointestinal Tract > Flashcards

Flashcards in Microbiology of the Gastrointestinal Tract Deck (156)
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1

Approximately how many bacteria are there in the GI tract? 

1014

2

Where are the majority of the bacteria in the GI tract found? 

In the colon

3

What is the name given to the bacteria in the GI tract? 

Normal flora 

4

What are the beneficial roles of normal flora? 

  • Synthesise and excrete vitamins 
  • Prevent colonisation by pathogens 
  • Kill non-indigenous bacteria 
  • Stimulate the development of GALT
  • Stimulate production of natural antibodies 

5

What vitamins are synthesised and excreted by the normal GI flora? 

  • Vitamin K 
  • Vitamin B12
  • Thiamine

6

How does the normal GI flora prevent colonisation by pathogens? 

  • Space
  • Bacteriosides 

7

What aspect of the normal GI flora kills non-indigenous bacteria? 

Bacteriosides 

8

What are the possible ways of categorising bacteria? 

  • Cocci or Bacilli
  • Gram positive or negative 
  • Aerobic or anaerobic 
    • Obligate or faculative
  • Do they form protective endospores or not? 
  • Can they stick to surfaces using pili and/or slime

9

Give two examples of bacteria that can form protective endospores? 

  • Bacillus Anthrax 
  • Clostridium Tetani 

10

What is true of obligate aerobes? 

They must have oxygen

11

Give two examples of obligate aerobes? 

  • Pseudomonas
  • Mycobacterium TB

12

What is true of obligate anaerobes? 

They die in the presence of oxygen 

13

Give two examples of obligate anaerobes

  • Bacteroides fragilis
  • Clostridial organisms 

14

Why may clostrial organisms be able to survive in oxygen? 

They form protective spores 

15

What is true of facultative anaerobes?

They prefer oxygen, but can live without it 

16

Give two examples of facultative anaerobes?

  • Gram -ve enteric bacteria, such as E. coli 
  • Gram +ve skin-dwellers such as Staphylococcus

17

Where are the anaerobic zones in the GI tract?

  • Parts of mouth 
  • Small bowel 
  • Colon

18

What parts of the mouth are anaerobic? 

  • Tounge
  • Deep in taste buds
  • Biofilm between teeth 
  • Gingival crevice areas

19

What can bacillus cause? 

Anthrax

20

What are the characteristics of bacillus?

  • Bacilli
  • Gram +ve
  • Aerobic

21

What are the characteristics of bacteroides fragilis?

  • Bacilli
  • Gram -ve
  • Anaerobic

22

What are the characteristics of bordetella pertussis?

  • Bacilli
  • Gram -ve
  • Aerobic
  • Non enteric

23

What are the characteristics of brucella?

  • Bacilli
  • Gram -ve
  • Aerobic
  • Non enteric

24

What are the characteristics of campylobacter?

  • Bacilli
  • Gram -ve
  • Aerobic
  • Enteric

25

What are the characteristics of clostridia

  • Bacilli
  • Gram +ve
  • Aerobic

26

Give 3 subspecies of clostridia

  • Tetani
  • Perfringens
  • Difficile

27

What does corynebacterium cause? 

Diphtheria 

28

What are the characteristics of corynebacterium?

  • Bacilli
  • Gram +ve
  • Aerobic

29

What are the characteristics of E. coli?

  • Bacilli
  • Gram -ve
  • Aerobic
  • Enteric

30

What are the characteristics of enterococci? 

  • Cocci
  • Gram +ve
  • Aerobic