gas infection

Question 1

gas infection viruses pathogen

Answer 1

1. rotavirues

2. norovirues

Question 2

virual pathogenesis

Answer 2

1. viral penetration and replication in gut mucosa

2. exposed immature epithelial cells do not have the absorptive capacity of mature cells

Question 3

most common viral gastro in infants and children

Answer 3

rotavirues

Question 4

low-income contries

Answer 4

rotavirus

Question 5

high-income countries

Answer 5

norovirus

Question 6

most common gas in adult

Answer 6

Norovirus

Question 7

winter vomiting disease

Answer 7

Norovirus

Question 8

norovirus treatment

Answer 8

oral rehydration

Question 9

rotavirus treatment

Answer 9

oral vaccine

Question 10

route of acquistion and transmission

Answer 10

faeces,from humans or animals containign pathogenic microbes or their toxins.
contaminated food , fluid, fingers ingest by human .

route of transmission:

1. person-to-person:feacal-oral route
2. water-borne
3. food-borne

Question 11

bacterial GIT disease mechanisms

Answer 11

1. ingestion of the pre-formed toxin
2. ingestion of viable organisms
   a. may produce toxini or not
   b. may invade epithelial cells or not

Question 12

describe ingestion of the pre-formed toxin

Answer 12

1.food containing toxin is ingested
2.organism may be dead( but toxin heat stable)
3.rapid onset
4.major causes:
staphylococcus aureus SEB &SEA……..
bacillus cereus emetic toxin/3 enterotoxins(heat-stable)/associated with rice dishes
clostridium botulinum botulinum toxin

Question 13

describe mechanisms of ingestion of viable organisms

Answer 13

1. infective dose/incubation period/ symptoms/duration of symptoms/site of infection
2. produce disease by:mucosal invasion& produce toxin

Question 14

mucosal invasion organisms

Answer 14

salmonella
shigella
campylobacter
yersinia enterocolitica
E.coli(some)

Question 15

salmonella transmission

Answer 15

improper cooking or storage

poultry and egg high risk

Question 16

campylobacter

Answer 16

campylobacteraceae: G- thermophilic(42) and microaerophilic

Question 17

developed countries diarrhea most common bacterial

Answer 17

campylobacter

Question 18

bacterial diarrhoea procedure salmonella

Answer 18

1. ingest pathogen.
2. absorbed to epithelial cells in small intestine.
3. bacteria penetrate cells and migrate to lamina propria layer of ileocaecal region.
4. multiply in lymphoid follicles
5. polymorphonuclear leukocytes confine infection to gastrointesinal tract.
6. inflammatory response meidates release of prostagiandins.
7. stimulates cAMP and active fluid secretion
8. diarrhoea

Question 19

vibrio cholera toxin

Answer 19

cholera toxin(heat labile enterotoxin)

• –active adenylate cyclase producing elevated elevated levels of cAMP
• –Results in increased fluid secretion and decrease in fluid absorption.

Question 20

shigella toxin

Answer 20

shinga toxin

—–act by cleaving rRNA, stop protein synthesis, kills colonic cell

Question 21

clostridium perfringers toxin

Answer 21

Type A strains produce alpha toxin

Type c strains produce beta toxin

Question 22

clostridium difficile toxin

Answer 22

exotoxin A &B and binary toxin
toxinA —fluid loss
toxinB—cell death

Question 23

enteric fevers(typhoid and paratyphoid)

Answer 23

salmonella typhi and S. paratyphi ABC

spread around the body in macrophage

Question 24

listeriosis

Answer 24

listeria monocytogenes
food-borne pathogen
present as meningtis
soft cheese

Question 25

systemic infection initiated in the GIT

Answer 25

1. enteric fever(typhoid and paratyphoid)—-salmonella typhi
2. listeriosis
3. viral hepatitis :A&E