Id 1Y3: Gastroenteritis

Front 1

Mechanisms used by pathogens?

Name 4

Back 1

Secretory Toxins (cholera) - inhibit absorption / promote secretion

Cytotoxins (Shiga/C.Diff) - destroy cells

Invasion (bacteria/virus breach epithelial cells)

Neurotoxins (staph enterotoxin, B. cereus) vomiting predominates

Front 2

Generalization of insult to commonly observed manifestation

Virus, toxins:

Small bowel dysfunction:

Bacterial colitis, colon:

Back 2

Toxins, virus (esp. norovirus)
- Vomiting, little if any diarrhea:

Small bowel dysfunction
- Nonbloody diarrhea

Bacterial colitis, colon
- Bloody diarrhea:

Front 3

Toxins:

Cause of traveler's diarrhea?

Back 3

Enterotoxigenic E. Coli (ETEC)

Front 4

Cholera toxin: ADP ribosylase

How does cholera toxin mediate enhance Cl/HCO3- secretion?

Back 4

•The A subunit of cholera toxin ADP-ribosylates, and thereby irreversibly activates, the G (stimulatory) component of adneylate cyclase. --> Enzyme is locked in “on” position, remaining bound to GTP. --> Elevated levels of cAMP result.

Cl-secretion is enhanced, as is bicarbonate secretion. Sodium accompanies as does water.

Front 5

What should be given in addition to salt/water that has been shown to have better outcomes in sepsis patients?

Back 5

glucose; enhances Na absorption via SGLT1 (sodium driven glucose co-transporter) in the enterocyte

Front 6

Mainstay of treatment for sepsis is?

Back 6

Replenish fluid/electrolyte loss

Front 7

Shiga toxin

produced most commonly by?

A subunit binds to what? and has what effect?

Back 7

E. Coli O157:H7

A subunit binds large eukaryotic ribosomal subunit and halts protein synthesis

Front 8

Shiga toxin

Systemic effects?

Back 8

Toxin gets into system and injures small blood vessels, which in turn respond to injury by forming thrombi;

Front 9

What is the most common cause of bacterial diarrhea in NA?

Through what is it transmitted?

Related to what other disease processes?

Back 9

Campylobacter jejuni and campylobacter coli.

Poultry, Milk, Animals

Guillan Barre Syndrome

Front 10

What organism causes traveler's diarrhea?

What type of diarrhea is this?

Back 10

Enterotoxigenic E. Coli (ETEC)


secretory

Front 11

Severe infantile diarrhea is caused by which organism?

How does it work?

Back 11

Enteropathogenic E. Coli (EPEC)

Binds to cells and injures them

Front 12

Which type of E. Coli transmits through meat and produces Shiga toxin 1 and 2

Best identified/diagnosed using what agar?

Back 12

Enterohemorrhagic E. Coli (EHEC)
aka Shiga toxin producing E.coli

Sorbitol MacConkey agar (because they don't ferment sorbitol)

Front 13

Salmonella

Primarily affects what age populations?

Antibiotics might have what effect on infection?

Back 13

Infants, elderly, immune compromised

Prolong carriage

Front 14

Salmonella Typhi

Invades which cells?

Replicates in?

Course of infection?

Back 14

Invades M cells

Replicates in Peyer's patches,

Chronic febrile illness

Front 15

Salmonella Typhi

Main symptoms?

Main reservoir?

Antibiotics/Vaccine?

Back 15

Constipation >> diarrhea

Humans = only reservoir

Antibiotics = ABSOLUTELY indicated
Vaccine = preventable (live attenuated or killed polysaccharide)

Front 16

Yersinia

Course/Intensity?

Main vehicle?

Back 16

Seasonal; occurs around holidays; not often a fulminant infection

Pork = main vehicle

Front 17

C. Difficile

Found/transmitted how/where?

Spread in what setting?

Treatment?

Back 17

Found in intestines (NF); can also be acquired

Nosocomial spread

Vancomycin, metronidazole; Probiotics might prevent

Front 18

C. Difficile

Pathological complications? (name 2)

Back 18

Pseudomembranes

Erupting Volcanoes

Front 19

What is the leading cause of viral diarrhea world wide?

Back 19

Rotaviruses

Front 20

Diarrheagenic Parasites

Given the following, name the organism:
- rare in NA
- Chronic disease/carriage
- Amebic dysentery
- Treat with metronidazole

Back 20

E. histolytica

Front 21

Diarrheagenic Parasites

Given the following, name the organism:
- most common parasite in NA, but diminishing in frequency
- Nonbloody chronic diarrhea
- Diagnose by microscopy or antigen test
- Treat with metronidazole

Back 21

Giardia lamblia

Front 22

Diarrheagenic Parasites

Given the following, name the organism:
- very severe disease
- nonbloody chronic diarrhea
- diagnose by microscopy or antigen test
- treat with nitazoxanide

Back 22

Cryptosporidium parvum

Front 23

Treatments

Antibiotics:

Mixed efficacy:

Contraindicated:

Back 23

Antibiotics: Shigella, Vibrios, ETEC

Mixed efficacy: Campylobacter, Yersinia

Contraindicated: EHEC, most Salmonella (ex. Typhi, or invasive illnesses)

Front 24

Treatments

Parasites?

Viruses?

Back 24

Parasites: metronidazole (giardia), nitazoxanide, furazolidone

Viruses: none (replenish fluids/salt)

Bismuth subsalicylate

Probiotics, green bananas (for acute diarhhea)

Front 25

Treatments

Antimotility agents - Harmful in?

Opiods harmful/helpful?

Back 25

Antimotility agents (loperamide): Harmful in colitis, some bacterial diarrhea. Pure antisecretory effect is elusive

Opiods: contraindicated

Front 26

Chronic Diarrhea: Complications?

Back 26

- Stunting
- Malabsorption of meds
- Malabsorption of nutrients
- Under-appreciated