GIT

Question 1

both vomiting and diarrhea with a short incubation is characteristic of

Answer 1

staphylococcal aureus poisoning WHICH PRODUCE PREFORMD TOXIN

Question 2

Cl.perfrengens WHICH PRODUCE PREFORMD TOXIN has both diarhea and vomiting but a

Answer 2

longer incubation period

Question 3

which food caused vomting by bacillus cereus

Answer 3

rice WHICH PRODUCE PREFORMD TOXIN

Question 4

diarrheas caused by staphlycoccus only in

Answer 4

cooked meat bacillus poisoning

Question 5

Infection of small bowel non-inflammatory or minimal inflammation CAUSED BY which mecahnism

Answer 5

enterotoxin or adherence / superficial invasion

Question 6

clinical sign of infection in small bowel and what we found in culture

Answer 6

Watery diarrhea
no fecal leukocytosis

Question 7

Food poisoning (bacteria) name organisms and there morphology and in which food

Answer 7

1-Staphylococcus aureus G+ve cocci (two packets disease) diarrhea and vomiting also short incubation salad ,tuna fish
2-Bacillus cereus G+ve rod
Diarrhea form cooked meat
Vomiting (Emetic) form Rice
3-Clostridium perfringens G+ve rod diarrhea and little vomiting also longer incubation
4-Clostridium botulinum G+ve rod Botulism disease Flaccid Paralysis Canned food

Question 8

Viral Gastroenteritis suggestive Features

Answer 8

• Mean incubation period of 24-48 hrs
• Mean duration of 12-60 hours
• Morethan 50% of affected persons have vomiting
  no bacteria on culture

Question 9

Common viruses for viral gastroenteritis

Answer 9

Rotavirus
Human caliciviruses (Noroviruses,Sapovirus)
Astrovirus
Enteric adenovirus

Question 10

Pathogenesis for viral gastroenteritis

Answer 10

cause diarrhea by destroying or altering function of enterocyte at the villi but no in crypts

Villus cells are sodium-absorbing cells. See decreased sodium and water absorption
and reduced production of disaccharidases leading to carbohydrate malabsorption.

• Some also have proteins that stimulate fluid secretion

Question 11

Similarities between norovirus and rotavirus

Answer 11

non inflammatory watery diarrhea + no wbc or blood

both seen in cooler months

Question 12

differences between norovirus and rotavirus

Answer 12

Rota noro

Young adults
fever low grade fever
live oral vaccine no vaccine
rapid antigen assays cant work on it

Question 12

differences between norovirus and rotavirus

Answer 12

Rota noro

Young adults
fever low grade fever
live oral vaccine no vaccine
rapid antigen assays cant work on it

Question 13

Name an organism that can cause bacterial infection of small bowel

Answer 13

cholera
ecoli

Question 14

morphology of cholera

Answer 14

gram negatiave rod

Question 15

is cholera enterotoxin or exotoxin

Answer 15

enterotoxin

Question 16

clinical presention , pathogenisis and mangament of cholera

Answer 16

rice water stool

A = Active —> go to cytosol and act on Gs supunit —-> increase cAMP——–> increase protein kinase which will ead to water and elcetrocyte loss
/
B binding

management if adequte water replacement

Question 17

Ecoli morphology

Answer 17

G-ve bacillus (rod_

Question 18

How dose ecoli handel ph and how dose it transmit

Answer 18

very sensitve to ph
transmmitted by contaminnated water

Question 19

What are the types of E.coli that cause watery travelers diarrhea

Answer 19

Enterotoxigenic E.coli (ETEC)
Enteropathogenic E.coli
enteroaggregative E.coli

Question 19

How dose ecoli cause watery diarrhea in small intestine

Answer 19

By
1-labile toxin —-> stimulate cAMP adenylate cyclase by ADP-ribosylatin;
2-stable toxin stimulates guanylate cyclase

Question 20

Major pathogenic factor of bloody diarrhea by ecoli(hemolytic uemic syndrome ) and which organ and lap finding

Answer 20

Shiga toxin that inhibit protein synthesis in enterocyte by removing adenine from 28S ribosomal RNA

Large intestine

RBC IN STOOL

Question 21

Organism that cause bloody diarrhea + gramnegtive rod in large bowel

Answer 21

E.coli
Shigella dysenteriae
Salmonella
campylobacter jejuni

Question 22

Bloody diarrhea caused by ecoli have a toxin mediated toxin what is it and what the clinical picture of it in large intestine

Answer 22

enterohemorrhagic E.coli (shiga toxin)

dysentery lile picture with pain griping fever .

Blood and mucous + WBCs in stool

Enteroinvaseive E.coli

no blood

Question 23

WHat organ dose Shigella affect and the morphology

Answer 23

Large inestine

G-ve rod non-lactoe fermenting color less

Question 24

pathogenisis of shigella and resistance to what

Answer 24

affect human only , shiga toxin

gastric acidity

Question 25

Lab Diagnosis of shigella

Answer 25

methylene blue of stool to know if neutrophil are there or not

Question 26

transmatiion of shigella

Answer 26

fecal-oral

Question 27

clinical presention of shigella

Answer 27

Watery then bloody severy abdomin pain

treatment with fluid and antibiotic

Question 28

Descripe the morphology of salmonella(non typhoidal) nad cultural characteristics

Answer 28

G-neg
non lactose fermenting

Question 29

Pathogenisis of salmonella

Answer 29

Animal source (سلحفاه )
enterocoltits —-> relase pro inflamnmatory cytokines by infected cell casueing systemic signs (fever)

Question 30

Clinical presenention of salmonella

Answer 30

abdomin pain + diarrrhea with or without blood
fever

Question 31

Clinical presenention of salmonella

Answer 31

abdomin pain + diarrrhea with or without blood
fever

Question 32

WHat organ dose campylobacter jejuni affect and the morphology

Answer 32

curved g-ve rod

Question 33

Pathogenisis of campylobacter jejuni

Answer 33

Animal source (puppies)
enterocoltits —-> relase pro inflamnmatory cytokines especially under 5 years old

Guillain -barre syndrome : immune disease => antbody against c.jejuni cross react with antigens of neurones

Question 34

lap of cl.campylobater

Answer 34

stool specimen cultured on blood agar microaerophilic