session 9- GI infections

Question 1

3 main non bacteria/virus in gut toxins

Answer 1

nematodes, cestodes, trematodes

Question 2

what are the gi defences

Answer 2

saliva, gastric acid, bile, colonic mucus, anaerobic environment

Question 3

benefits microbiome

Answer 3

competition for nutrients, produces antimicrobial substances, produce vitamin K

Question 4

what do bacteria in colon produce

Answer 4

short chain fatty acids such as acetate, butyrate and propinoate

Question 5

role acetate

Answer 5

cholesterol metabolism

Question 6

role butyrate

Answer 6

energy source for colonocytes

Question 7

role propinoate

Answer 7

regulate satiety

Question 8

what is FMT

Answer 8

transport of faecal better to patients to replenish gut microbiota

Question 9

how to carry out FMT

Answer 9

NG tube, upper GI endoscope, colonoscopy, transplant to caecum

Question 10

gram negative bacteria causing infections

Answer 10

salmonella, campylobacter, shigella, Enterotoxic e coli.

Question 11

gram positive bacteria causing infections

Answer 11

Clostridium difficile

Question 12

symptoms salmonella

Answer 12

nausea, vomiting and diarrhoea, fever, abdo cramping.

Question 13

how spread salmonella

Answer 13

ingesting contaminated food and bacteria.

Question 14

how does salmonella cause symptoms in body

Answer 14

enters enterocytes, then to submucosa. enters macrophage. transferred to RES. multiple causing lymphoid hyperplasia, re-enter gut from liver

Question 15

shape campylobacter

Answer 15

s shaped.

Question 16

how campylobacter spread

Answer 16

faecal-oral

Question 17

symptoms campylobacter

Answer 17

longer incubation period, fever, abdo cramping, diarrhoea.

Question 18

spread shigella

Answer 18

infected stool, person to person, flies

Question 19

how does shigella cause disease

Answer 19

small dose invades coloncytes and neighbouring cells. kills colonocytes and forms abscesses in mucosa.

Question 20

symptoms shigella

Answer 20

bloody diarrhoea with mucus and abdo cramping

Question 21

E coli spread

Answer 21

faecal oral or water

Question 22

enterotoxic e coli acryonym

Answer 22

ETEC

Question 23

symptoms ETEC

Answer 23

watery diarrhoea.

Question 24

how does ETEC cause symptoms

Answer 24

adheres to enterocytes to cause hypersecretion of chloride ions, and water to leave cells into gut lumen.

Question 25

which bacteria can cause haemolytic uraemia syndrome

Answer 25

shigella, campylobacter

Question 26

duration of infection compare

Answer 26

shortest- ETEC, salmonella, shigella, campylobacter -longest

Question 27

structure C difficile

Answer 27

gram positive anaerobic spore forming bacillus

Question 28

what are toxins A and B

Answer 28

A- enterotoxin that causes excessive secretion | B- cytotoxin that kills colonocytes

Question 29

what causes c Diff proliferation

Answer 29

antibiotics

Question 30

severe consequences of C diff infection

Answer 30

pseudomembranous colitis, toxic megacolon

Question 31

what is pseudomembranous colitis

Answer 31

elevated yellow plaques join to form a pseudomembrane.

Question 32

treatment c diff

Answer 32

remove antibiotic, fluid resuscitation, metronidazole or vancomycin, probiotics

Question 33

viral causes gastroentertiis

Answer 33

rotovirus, norovirus

Question 34

parasitic causes gastroenteritis

Answer 34

cryptosporidium, giarida.

Question 35

symptoms rotavirus norovirus

Answer 35

vomiting with fever, diarrhoea

Question 36

structure rotovirus

Answer 36

double stranded RNA

Question 37

how does rotavirus cause diarrhoea

Answer 37

chloride secretion, SGLT1 disruption, reduced brush border enzyme function

Question 38

how is cryptosporidium spread

Answer 38

faecal oral or water

Question 39

how does cryptosporidium cause disease

Answer 39

ingested oocyst reproduces in distal SI epithelial eels. excreted in faeces.

Question 40

symptoms cryptosporidium

Answer 40

watery diarrhoea

Question 41

symptoms giardia

Answer 41

persistent diarrhoea, abdo cramping

Question 42

life cycle giardia

Answer 42

cyst ingested, damages proximal SI causing symptoms. villous atrophy. parasite excreted to repeat cycle

Question 43

symptoms entamoeba histolytica

Answer 43

diarrhoea, liver abscess

Question 44

cause travellers diarrhoea

Answer 44

ETEC

Question 45

how does rotavirus cause diarrhoea

Answer 45

chloride secretion creates gradient for Na+ and water into lumen, SGLT1 disruption increases osmotic load in gut, brush border dysfunction causes general malabsorption