Bacteria affecting the GI tract - GI system

Question 1

The GI tract

Answer 1

• mouth
• oesophagus
• stomach
• small intestine
• large intestine

Question 2

gastroenteritis

Answer 2

• syndrome characterised by GI symptoms including nauseas, vomiting, diarrhoea and abdominal pain

Question 3

diarrhoea symptoms /associations

Answer 3

• abnormal faecal discharged characterised by frequent and/or fluid stool
• associated with increased fluid and electrolyte loss
• often disease of small intestine

Question 4

dysentery and common symptoms /associations

Answer 4

• abnormal inflammation of GI tract
• often blood and pus in faeces and pain, fever, abdomical cramps
• often disease of large intestine

Question 5

enterocolitis

Answer 5

• inflammation of musoca of small and large intestine

Question 6

bacteria that can cause/lead food poisoning

Answer 6

staph aureus
clostridium botulin
bacillus cerus

Question 7

staph aureus and food poisoning

Answer 7

growth in food after human contamination
produce heat stable enterotoxins (resistant to stomach acid and digest enzymes)
sever vomiting
toxin gives reaction not bacteria itself

Question 8

botulism

Answer 8

clostridium botulism
heat stable toxin
leads to flaccid paralysis and death

Question 9

bacillis cerenus

Answer 9

found in food
can grow in chains
leads to an acute reaction
gram + spore former
bacillus 
forms an enterotoxin 

can lead to vomiting or diarrhoea

Question 10

gastric ulcers and bacteria which is associated with

Answer 10

form in the mucosa of stomach
can rupture and cause bleeding/inflamamtion
helicobacter pylori

Question 11

how can helicobacter pylori survive in the stomach

Answer 11

• produces urease
• protective clod during transit to gastric mucin layer (pH 7)
• ammonia basis of breath test

Question 12

stomach barrier

Answer 12

gastric pH 1-2

Question 13

treatment of gastric ulcers

Answer 13

proton pump inhibitor plus metronidazole/amoxicillin and clarithromycin

Question 14

intestine infections can lead to and treatment

Answer 14

diarrhoeal treatment

fluid and electrolyte replacement essential

Question 15

E coli

Answer 15

gram - motile rod

causes diarrhoea

Question 16

genetic diversity of E coli due to

Answer 16

• plasmid, lysogenic phage and transposon encoded pathogenicity islands

Question 17

detection of E coli

Answer 17

lactose fermentation
go pink when on agar plate (macconky, hektoen enteric agar)
PCR/antigen tests for serotypes

Question 18

e coli pathogenic straisn

Answer 18

EPEC
ETEC
EHEC

Question 19

EPEC

Answer 19

bunding forming pili in attatchemtn - forms attatchemtn to cells via pedestal
injects proxies into host to manipulate cytoksletn, disruption of cili = diarrhoea

Question 20

ETEC

Answer 20

attach via adhesive pili

produced heat stable and laial enterotoxins

Question 21

EHEC

Answer 21

produces vero toxin STx
damages direct cells
can cause haemorrhage colitis/diaorhea

Question 22

shigella

Answer 22

shiga toxin producing
bacillary dysentry, bloody stoools
spread foetal orally

Question 23

samonella

Answer 23

salmonella typhimurium
invades Macrophage? cells and surrounding epitheloum
diarrhoea and enterocolitis

Question 24

lab detection E coli/samonella

Answer 24

Macconky
pink
E coli - lactose ferments

Samonella- non lactose fermenter
(green with black centered)

Question 25

Tymphoid fever caused by and complicatins

Answer 25

S typhi
infection initiating in intestine 
transported systemically via macrophages
complicaitons
-	GI lesions and haemorrhage
-	toxaemia – endocarditis
-	meningitis

Question 26

no 1 cause of food poisning

Answer 26

camplyobacter spp
gram - micro aerophilis

symptoms
ulceration in jejunm
diarrhoea

Question 27

cholera and what does it do

Answer 27

gram - comma shaped bacterium
large numbers required

change in sodium potassium pumps
usually a balance
increased secretion of chloride ions
stops sodium influx into cells, large loss of water

Question 28

virus causes of GI infections

Answer 28

rota virus
winter vomiting virus/noro virus

• mainly oral foetal

Question 29

rota virus

Answer 29

wheel like particle
diarrhoea caused by tissue damage in small intestine
low infectious dose

Question 30

winter vomitig virus

Answer 30

norovirus

chills headache fever vomiting