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Name 3 species of Vibrio.
- V. cholerae
- V. parahaemolyticus
- V. vulnificus
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Grow on simple media at wide temperature and pH ranges, but susceptible to stomach acid.
Vibrio
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Which form of Vibrio can grow without salt?
V. cholerae
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Vibrio:
1) Shape?
2) Flagella?
Curved rods with a single polar flagellum
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Which part of Vibrio;s LPS is used to divide it into serogroups?
O-polysaccharide
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Which forms of Vibrio cholerae produce cholera toxin?
O1 & O139
Note: Serogroup 1 can be further subdivided into serotypes.
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Name the two biotypes of V. cholerae O1.
Which one caused the first 6 pandemics?
Which one caused the 7th?
- Classical (first 6)
- El tor (7th)
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What does Vibrio's capsule do?
Helps disseminate the infection
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What forms of Vibrio produce a capsule?
V. vulnificus and non-O1 V. cholerae (NOT produced by V. cholerae O1- bacteria don't spread beyond intestine)
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What is unique about V. cholerae and V. vulnificus?
They have two circular chromosomes. Each chromosome is essential.
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Vc Pathogenesis: Biological effect of cholera toxin.
Hypersecretionof electrolytes and water.
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Vc Pathogenesis: Biological effect of toxin co-regulated pilus.
Adherence to intestinal mucosal cells; binding site fo r CTXp
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Vc Pathogenesis: Biological effect of accessory cholera enterotoxin.
Increases intestinal fluid secretion
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Vc Pathogenesis: Biological effect of Zonnula occludens toxin.
Increases intestinal permeatibility
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Vc Pathogenesis: Biological effect of neuraminidase.
Modifies cell surface by cleaving sialic acid to increase GM1 binding sites for cholera toxin.
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What encodes genes for the 2 subunits of cholera toxin (ctxA and ctxB) in V. cholerae?
Bacteriophage CTXφ
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CTXφ binds _____ and moves into the bacterium where it becomes integrated into the bacterial genome.
toxin co-regulated pilus
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Name 2 toxins Bacteriophage CTXφ encodes other than the cholera toxin.
- Accessory cholera enterotoxin gene (ace)
- Zonnula occludens toxin gene (zot)
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What coordinates the Bacteriophage CTXφ virulence genes?
ToxR regulator
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Cholera toxin is an _____ toxin. This is similar to the ___ toxin of ____
- A-B
- Heat-labile (LT) of E. coli
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What do the five B subunits of V. cholerae bind to?
Ganglioside GM1 on intestinal epithelial cells
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What does the A subunit of V. cholerae toxin do?
Becomes internalized (only A subunit, NOT B) and activates adenylyl cyclase -> ATP is catalyzed to cAMP and hypersecretion of electrolytes
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Thermostable direct hemolysin is a virulence factor of
V. parahaemolyticus
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Antiphagocytic polysaccharide capsule, siderophores and cytolysis are a virulence factor of
V. vulnificus
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V. parahaemolyticus induces chloride ion secretion in epithelial cells by increasing ______
intracellular calcium
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Which strand of Vibrio is useful in classifying virulent strains? What type of hemolysis does this show on blood agar?
Vibrio parahaemolyticus, Beta-hemolysis
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Virulent strains of V. parahaemolyticus are called?
Kanagawa positive
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Where are Vibrio species commonly found.
Water (especially salinious water with chitinous shellfish)
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How is cholera spread?
Contaminated water and food (oysters), usually in places with poor sanitation
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Most common cause of GI disease in Japan and SE Asia.
V. parahaemolyticus
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Most common Vibrio species causing GI disease in US?
V. parahaemolyticus
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Vibrio species that produces severe, often fateal, wound infections.
V. vulnificus
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V. cholerae
1) Source of infection:
2) Disease:
- 1) Water, food
- 2) Gastroenterititis
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V. parahaemolyticus
1) Source of infection:
2) Disease
- 1) Shellfish, seawater
- 2) Gastroenteritis, wound infection, bacteremia
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V. vulnificus
1) Source of Infection:
2) Disease:
- 1) Shellfish, seawater
- 2) Bacteremia, wound infection, cellulitis
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Two main serotypes of V. cholerae
O1 and O139
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What bacteria produces "rice water stool"? What is rice water stool?
V. cholerae
Colorless, odorless, and speckled with mucus
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V. cholerae mortality:
Untreated:
Treated:
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How many days after ingestion do symptoms of cholera appear?
2-3 days (get watery diarrhea and vomiting)
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How long after ingestion, does it take for V. parahaemolyticus symptoms to occur? What are these symptoms?
- 5-72 hours
- Explosive, watery diarrhea
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How do you treat V. parahaemolyticus?
Self-limited diarrhea, No treatment
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What bacteria is responsible for 1) wound infections after exposure to contaminated seawater and 2) septicemia after consumption of contaminated oysters.
V. vulnificus
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Vibrio diagnosis must be collected early in the disease and if not, the specimen should be mixed in _____ and refrigerated.
Cary-Blair transport medium
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Can Vibrio grow on blood or MacConkey agar?
Both
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Name a selected agar for Vibrio.
Thiosulfate citrate bile salts sucrose (TCBS)
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How do you treat V. cholerae?
Prompt tx with fluid and electrolyte replacement before the fluid loss leads to shock. (Antibiotic therapy can help reduce bacteria and thus toxin production, but it is secondary to fluid replacement.)
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Which antibiotics would you use as secondary tx in cholera patients:
1) Adults:
2) Pregnant Women:
3) Children:
- 1) Adults: Doxycycline or tetracycline
- 2) Pregnant Women: Furazolidone
- 3) Children: Sulfa-trimethoprim
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Which strain of cholera is often resistant to furazolidone and sulfa-trimethoprim?
O139
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How do you treat V. parahaemolyticus GI disease?
Fluids and electrolytes; antibiotics in severe cases
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How do you treat V. vulnificus wound infections and septicemia?
Minocycline + fluoroquinolone or cefotaxime
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Campylobactor
1) Gram-P or Gram-N
2) Shape
3) Flagellum
4) Aerobic/Anaerobic
5) Able to oxidize or ferment carbohydrates?
6) Oxidase-P or Oxidase-N
- 1) Gram-N
- 2) Comma or S-shaped
- 3) Single polar flagellum
- 4) Microaerophile
- 5) Unable to oxidize or ferment carbs
- 6) Oxidase-P
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What are the two most frequent bacterial causes of gastroenteritis in the USA?
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What is the most common cause of C. jejuni infection?
Poultry via fecal-oral route
Does NOT spread via water or person-to-person
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Name 3 species of Campylobacter
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Which species of Campylobacter has a propensity to spread to the bloodstream?
C. fetus
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What capsule proteins makes Campylobacter resistant to complement- and antibody- mediated lysis?
S protein
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What two types of lysis are Campylobacter resistant to?
Complement- & Antibody- mediated lysis
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Which type of Campylobacter can cause Guillian-Barre?
C. jejuni
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C. jejuni can present with what type of diarrhea?
Bloody diarrhea
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What bacteria can cause spontaneous abortion in pregnant women?
Campylobacter
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What type of bacteria does Campylobacter produce?
Greenish-watery foul-smelling diarrhea (maybe followed by bloody diarrhea)
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What bacteria produces a greenish watery foul-smelling diarrhea?
Campylobacter
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How do you treat Campylobacter?
Self-limiting
Severe cases can be given Erythromycin or azithromycin , tetracylines or fluoroquinolones.
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Campylobacter definitive diagnosis can only be made by detecting the bacteria in ______.
Stool Cultures
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Autoimmune disorder of the peripheral nervous system that is characterized by symmetrical weakness.
Guillian Barre
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Antibodies directed against ________ LPS can damage neural tissue and cause _______
Campylobacter jejuni, Guillian Barre
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What serotype of Campylobacter is Guillian-Barre associated with?
O:19
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Does Campylobacter grow on MacConkey?
No, it only growths on Campylobacter selective agar microaerophilically at 42 C.
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What antibiotics are Campylobacter resistant to?
Penicillins, cephalosporins, sulfonamides
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Name 3 diseases for H. Pylori
- Gastritis
- Peptic Ulcers
- Risk factor for gastric carcinoma
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Gastritis:
Gastroenteritis:
- Gastritis: Inflammation of stomach mucosa
- Gastroenteritis: Inflammation of stomach and intestines
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H. pylori:
1) Gram-P or Gram-N
2) Shape
3) Motile
4) Location
5) Oxidase-P/N
6) Urease-P/N
- 1) Gram-N
- 2) Rod
- 3) Highly motile
- 4) Found in gastric mucous layer/ epithelial lining of the stomach
- 5) Oxidase-P
- 6) Urease P
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H. pylori:
_______ deficient mutants do NOT colonize the stomach and do NOT cause pathology.
Urease
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H. pylori:
Urease can bind to _______ bearing cells and cause apoptosis.
MHC class II
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Dyspepsia (upset stomach), bloating, indigestion, nausea, upper abdominal pain, weight loss and heartburn are indications of?
Helicobacter
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How do you treat Helicobacter?
- Antibiotics for 1-2 wks:
- Tetracycline, metronidazole, and omeprazole
- Bismuth Salts (Pepto-Bismol)
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How is Helicobacter trasmitted?
50% of patients w/ H. pylori are + for the bug in their ___
- Person-to-person transmission
- dental plaque (gross)
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Name 3 ways to diagnose H. pylori.
- Gastric biopsy
- Non-invasive Urease Test (C14-based urea breath test)
- Anti-H. pylori antibodies in serum
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Aeromonas hydrophila
1) Found in?
2) Oxidase-P/N
3) Aerobic/Anaerobic
- 1) Aquatic environments --> hydrophila, duh
- 2) Oxidase-P
- 3) Facultative anaerobe
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Aeromonas hydrophila Treatment:
1) Acute diarrhea
2) Chronic diarrheal disease or systemic infection
3) Resistant to?
- 1) Self-limiting
- 2) Ciprofloxacin; aminoglycosides and sulfa-trimethoprim are also active
- 3) B-lactam antibiotics and erythromycin
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