Week 9 - Microbiology of GI tract Flashcards Preview

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Flashcards in Week 9 - Microbiology of GI tract Deck (47):
1

Wha is the gram status of psuedomonas aeruginosa?

-Gram negative bacilli

2

Give two examples of obligate aerobes

-Mycobacterium tuberculosis
-Pseudomonas aeruginosa

3

Give two obligate anaerobes

-Bacteriodes fragilis
-Clostridium spp.

4

Name the anaerobic areas of the GI tract

-Parts of the mouth
-Small bowel
-Colon

5

Why are colonic bacteria essential for life?

-Prevent colonisation by pathogenic bacteria
-Synthesise and excrete essential vitamins eg B12
-Stimulate production of natural antibodies

6

What are consequences of a diminished microbiota

-Increased susceptibility to infection
-Vitamin deficiencies
-Poorly developed immune system

7

Name two bacteria which can form endospores

-Clostridium tetani
-Bacillus anthracis

8

Name 3 aerobic gram positive cocci species

-Staphylococcus
-Streptococcus
-Enerococcus

9

Name 2 aerobic gram negative cocci

-Neisseria meningitidis
-Neisseria gonorrhoeae

10

Name some gram positive bacilli species

-Clostridia
-Lactobacillus

11

Name 3 gram negative enteric bacilli

-E.coli
-Bacteriodes fragilis
-Pseudomonas
-Klebsiella spp
-Salmonella spp.

12

What is the gram status of Haemophilus influenzae

-Gram negative bacilli

13

Name some bacteria which colonise the mouth

-Strep
-Staph
-lactobacilli

14

When can mouth bacteria begin to be problematic?

-When the host is malnourished, dehydrated or immunocomprimised

15

Who is at risk of oral thrush?

-Neonates
-Immunocomprimised
-Antibiotics
-Diabetics
-Steroid use

16

What is angular chylosis?

-Inflammation of corners of mouth caused by thrush

17

How is oral thrush treated?

-Nystatin suspension

18

What bacteria often causes dental caries/gingivitis?

-Step mutans (viridans)

19

What is ludwig's angina?

-Cellulitis of the neck, usually caused by strep mutans
-Rapid progression can lead to asphyxiation via closure of the larynx

20

What three sites are swabbed for MRSA upon entering hospital?

-Nose, throat and perineum

21

What are the main bacteria which colonise the nose?

-Strep and staph

22

Name 3 bacteria which normally colonise the throat

-Viridans strep
-Staphylococci
-Niesseria Meningitidis

23

When can viridans streptococci become problematic?

-During dental procedures and anesthesia bacteria may enter blood stream
-Usually cleared but can stick to prosthesis and orthopaedic implants and cause infection

24

Which group of organisms is mainly responsible for tonsillitis? Name the common organism

-Viruses
-Adenovirus

25

What is the main bacterial cause of tonsillitis?

-Strep pyogenes

26

What is a quincy?

-Abscess of the tonsil

27

What GI pathology is commonly associated with H.pylori?

-Duodenal/gastric ulcers

28

Name 3 common colonic bacteria

-Bacteroides fragilis
-Eschericia Coli
-Enterococcus Faecalis

29

Why are prophylactic antibiotics used in gut surgery?

-Operations on the gut often have abnormal flora and there is a high risk of wound infection

30

Name an antibiotic regime used in surgical prophylaxis

-Co-amoxiclav

31

What is pseudomembranous colitis?

-Inflammation of the colon caused by c.difficile infection

32

What is the cause of a perianal abscess?

-Blockage of anal gland by faecal matter caused stasis of bacteria leading to multiplication and abscess formation

33

What colonic bacteria are found perianal skin?

-E.coli
-Enterococcus

34

Where are lactobacilli the common commensal?

-Vagina

35

What makes lactobacilli advantageous to the vagina?

-Converts glycogen to lactic acid to creat an acidic environment which prevents other bacteria and candida albicans from growing

36

What is the most common cause of UTIs?

-E.coli from GI tract
(then enterococcus faecalis and klebsiella)

37

What is specific about an infection with pseudomonas aeruginosa?

-Produces green pus in moist environments

38

What bacteria is responsible for wet/gas gangrene? Explain the process

-C.perfringes
-Anaerobic digestion of glucose leads to ethanol and CO2 producing bubbles in the skin

39

Give two characteristic features of tetanus

-Risus sardonicus (lock jaw)
-Opisthotonus

40

What is the most common cause of nausea and diarrhoea?

-Norovirus

41

What is the most common cause of gastroenteritis?

-Contaminated food or drink

42

What are the most common organisms which cause gastroenteritis?

-Salmonella
-Campylobacter
-Listeria

43

What bacteria produce toxins in food which can cause nausea and vomitting?

-Staphylococci
-Clostridium

44

What is the result of infection with vibrio cholera?

-Effects the ileum to cause water and salt to be actively secreted into the lumen leading to diarrhoea
-Characteristically looks like 'rice-water'
-Rapid severe dehydration follows
(cholera)

45

Name 2 protozoans which can cause gastroenteritis

-Giardia
-Cryptosporidium

46

Name 4 causes of travellers Diarrhoea

-E.coli
-Samlonella
-Campylobacter spp.
-Rotavirus

47

What is the gram status of Staphylococcus?

-Gram positive cocci