Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI > Other GI Bacteria > Flashcards

Other GI Bacteria Flashcards

1
Q

Name the other bacteria (aside from E coli, Shigella, Salmonella, and Yersina) that we discussed:

A 
Vibrio spp
Campylobacter jejuni
H pylori
S. aureus
B cereus
Listeria monocytogenes
Clostridium spp.:
   - C perfringens
   - C. botulinum
   - C. difficile
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What metabolic characteristic differentiates Vibrio spp. from Enterobactericae?

A

Vibrio are oxidase positive, unlike enterobactericae

Campylobacter jejuni is also oxidase-positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which genus is found in salt water?

A

Vibrio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the morphology and motility of Vibrio spp.

A

Comma-shaped; darting motility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Sodium deoxycholate is added to bacteria. When touched with an inoculation loop, a mucoid string stretches from the plate. What is this called, and what is the bacteria?

A

String test: sodium deoxycholate dissolves DNA of Vibrio, causing mucoid string

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Buzzword: agent O/129

A

Bacteriostatic to Vibrio spp.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In what environments are Vibrio found?

A

Water: fresh, salt, brackish

More common in warmer months due to association with water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Buzzword: Shellfish

A

Vibrio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Buzzword: Ice cream

A

Vibrio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the causative agent of cholera?

A

Vibrio cholerae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a likely agent of septicemia following ingestion of seafood?

A

Vibrio vulnificus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Aside from ingestion, what is another mode of transmission of Vibrio vulnificus?

A

Inoculation of open wounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does cholera toxin cause symptoms?

A

It stimulates a hyperactivation of adenylate cyclase (the A subunit of the AB toxin catalyzes ADP ribosylation of the Gs protein, locking it in active state).

This causes an accumulation of cAMP

This causes hypersecretion of electrolytes/water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Buzzword: rice water stool

A

Cholera

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is one method of increasing chances of recovery/isolation of Vibrio cholerae from a stool sample?

A

Enrichment in alkaline media

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the treatment for Vibrio infection?

A

Fluid/electrolyte replacement (oral and/or IV)

Antimicrobial such as azithromycin

17
Q

Buzzword: “Seagull” appearance on microscopy

A

Campylobacter jejuni

18
Q

What is a unique metabolic characteristic shared by Campylobacter jejuni and H. pylori?

A

Both are microaerophilic: unable to grow in atmospheric concentrations of oxygen, but also unable to grow in anaerobic environments.

19
Q

What is the most common bacterial cause of diarrhea worldwide?

A

Campylobacter jejuni

20
Q

What are some of the virulence factors of Campylobacter jejuni?

A

Flagellum: aids motility, adherence, and invasion
Some strains produce heat-labile cholera-like enterotoxin
CDT: Cytolethal-distending toxin, an A-B toxin

21
Q

What does cytolethal-distending toxin do, and what organism is it associated with?

A

Associated with Campylobacter jejuni

Causes cell-cycle arrest, and the destruction of enterocytes, immune cells, and fibroblasts

22
Q

What is the reservoir for Campylobacter jejuni?

A

Warm-blooded animals (cattle, poultry, dogs, etc)

23
Q

How is Campylobacter transmitted?

A

Fecal-oral transmission - low infectious dose
Direct contact with warm-blooded animals, humans, ingestion of under-cooked poultry or meat, unpasteurized milk, or contaminated water

24
Q

Buzzword: Guillain-Barre Syndrome

A

Campylobacter jejuni

25
Q

Which organism causes disease most similar to a mild form of cholera?

A

Campylobacter jejuni: watery, dysenteric diarrhea with blood and pus, as well as abdominal pain and fever

26
Q

Which organism is associated with formation of abscesses in the intestinal crypts?

A

Campylobacter jejuni

27
Q

What medium is used to culture Campylobacter jejuni?

A

Skirrow medium, in microaerophilic conditions

28
Q

What is the treatment for disease caused by Campylobacter jejuni?

A

Typically, the disease is self-limited and does not require treatment.
For severe/prolonged (>1 week) disease, consider azithromycin.

29
Q

Metabolically, what is a major difference between H pylori and C. jejuni?

A

H pylori is urease-positive. Campylobacter is not.

Both are microaerophilic.

30
Q

What are some diseases associated with H pylori?

A

Gastritis, peptic ulcers, gastric carcinomas, and MALT lymphomas

31
Q

What is the reservoir for H pylori?

A

Humans only; present in ~50% of the population worldwide

32
Q

How is H pylori diagnosed?

A

Breath-urease test** (best, non-invasive)
Biopsy, isolation on Campylobacter media
Serology
Stool antigen detection

33
Q

How is H pylori treated?

A

2 options:

Bismuth Quadruple: bismuth, metornidazole, teracycline, and a PPI
Clarithromycin Triple: Clarithomycin, a PPI, and EITHER amoxicillin or metronidazole

34
Q

How are S aureus GI infections acquired? What causes symptoms?

A

Ingestion of contaminated food: food might be contaminated by someone with nasal colonization or an infected skin lesion.

Symptoms are caused by enterotoxins produced by S aureus; they are NOT caused just by bacterial replication.

35
Q

What kind of foods are more often contaminated by S aureus?

A

Rich foods: those made with creams, mayonnaise, dairy, meats, etc.
Toxin is heat stable!! Cooking does not deactivate.

36
Q

How soon after ingestion food contaminated by S aureus do symptoms occur?

A

2-8 hours

37
Q

How do S aureus symptoms differ if the toxin is ingested vs inhaled?

A

Ingestion S/S: diarrhea, vomiting, abdominal pain. (no fever, blood, or pus)

Inhalation S/S: fever, nauseau, vomiting, and difficulty breathing

38
Q

What virulence factors are associated with H pylori?

A

Urease: allows bacterial to break urea down into ammonia and CO2. The ammonia neutralizes stomach acid and create a more neutral microenvironment.

VacA: Vaculating cytoxin. Forms vacuoles in the mucosa.

CagA: alters the host’s actin cytoskeleton and stimulates cytokine production. Introduced to the host cell via a Type IV secretion system.

GI (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions