Term
| What is the source of Helicobacter pylori? |
|
Definition
|
|
Term
| Why does Hp grow in the gastric mucosa? |
|
Definition
| because of production of urease |
|
|
Term
| What facilitates colonization of Hp in the gastric mucosa? |
|
Definition
| Rise in pH due to ammonia |
|
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Term
| What promotes ulcer development in the stomach mucosa with Hp infection? |
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Definition
| Host immune response tries to eliminate Hp, but can't because of Hp's unusual niche, the immune response continues and promotes ulcer development. |
|
|
Term
| What virulence factors does Hp have? |
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Definition
Vacuolating cytotoxin VacA
Pathogenicity-associated island encoding a cytotoxin-associated protein (CagA) |
|
|
Term
| What type of ulcers are caused by Hp 95% of the time? |
|
Definition
|
|
Term
| What percent of Gastric ulcers are due to Hp, what are the remaining due to? |
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Definition
|
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Term
| What are Gastric adenocarcinomas and lymphomas mostly associated with? |
|
Definition
| current or past Hp infections |
|
|
Term
|
Definition
on Campylobacter medium with antibiotic susceptibilities
Microaerophilic G- curved rod |
|
|
Term
| What test can be done to detect CO2 generated from Hp urease? |
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Definition
|
|
Term
| Will anti-acid secretory agents cure Hp-caused ulcers? |
|
Definition
|
|
Term
| What is the treatment regimen for Hp? |
|
Definition
Control acid and 2 antibiotics
Omeprazole, metronidazole + Clarithromycin
(or tetracyclin or amoxicillin) |
|
|
Term
| What are the characteristics of Vibrio cholerae? |
|
Definition
Motile (single flagella)
Gram(-) oxidase(+) curved Rod Found in Aquatic ecosystems |
|
|
Term
| What strain of Cholerae is currently in 98 countries? |
|
Definition
|
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Term
| What type of toxin does cholerae produce? |
|
Definition
| Phage-encoded cholera toxin |
|
|
Term
| What 2 virulence factors does cholerea have? |
|
Definition
Phage-encoded cholera toxin
Toxin-co-regulated pilus |
|
|
Term
| What is required for the colonization of the GI tract by cholera? |
|
Definition
|
|
Term
| What are the sources/reservoirs of Cholera? |
|
Definition
Aquatic ecosystems, Brackish water
During outbreaks- contaminated water
Shell fish, other aquatic organisms
Gulf Coast |
|
|
Term
| What organism cause "rice water stool"? |
|
Definition
|
|
Term
| What are the sypmtoms of Cholera? |
|
Definition
Acute Watery Diarrhea
-mucus flacks in diarrhea (rice water)
Severe dehydration, acidosis |
|
|
Term
| What is responsible for the severe diarrhea of cholera? |
|
Definition
|
|
Term
| What type of toxin is the cholera toxin? |
|
Definition
AB toxin: 5 B subunits, 1 A subunit with activity
(Similar to ETEC) |
|
|
Term
| What causes the hypersecretion of fluids and electrolytes from the Cholera toxin? |
|
Definition
| ADP-ribosylated GTP-binding protein activates adenyl cyclase leading to an increased cAMP level |
|
|
Term
| What is the treatment of Cholera? |
|
Definition
IV Fluid/electrolyte replacement
Oral rehydration therapy
Antibiotics |
|
|
Term
| What organism is the most comon foodborne disease in Japan and epidemics of it have occured on cruises? |
|
Definition
|
|
Term
| What organism can cause potentially lethal septicemia and is associated with consuming raw oysters? |
|
Definition
|
|
Term
| What 2 organisms are the most common causes of bacterial foodborne illness in the US? |
|
Definition
| Salmonella and Campylobacter |
|
|
Term
| What are the characteristics of Campylobacter? |
|
Definition
Motile
Gram(-)
Oxidase(+)
spiral rods (pair look like sea gulls)
Microaerophilic (grows best at 42C - body temp of Birds) |
|
|
Term
| What is the most common source of Campylobacter jejuni? |
|
Definition
poultry, raw milk
(other: GI tract of wild and domesticated animals, pets, human-human transmission) |
|
|
Term
| What do ~40% of Guillain Barre syndrome patients have evidence of before onset of symptoms? |
|
Definition
|
|
Term
| What are the symptoms of Campylobacter infections? |
|
Definition
Watery to grossly bloody invasive diarrhea
Abdominal cramps, fever, vomiting |
|
|
Term
| What Campylobacter is more likely to cause severe septicemia and disseminated infections? |
|
Definition
|
|
Term
| How do Anaerobes get energy? |
|
Definition
| from fermentation of carbohydrates or breakdown of amino acids to amines |
|
|
Term
| What causes anaerobes to stink? |
|
Definition
Fermentation end products
-Long chain alcohols, and fatty acids
-breakdown of amino acids |
|
|
Term
| What organism is an abscess and tissue necrosis a Hallmark lesion for? |
|
Definition
|
|
Term
| What should you think of when you see Foul smelling breath, sputum, abscess? |
|
Definition
|
|
Term
| What contributes to Anaerobes sensitivity to oxygen? |
|
Definition
|
|
Term
| What is the most common anaerobic infection? |
|
Definition
|
|
Term
| Where do B. fragilis and P. melaninogenica both produce and both associated with? |
|
Definition
Both produce antiphagocytic capsules
Both associated with abscesses |
|
|
Term
| How are abcesses caused by B. fragilis and P. melaninogenica treated? |
|
Definition
Surgical drainage of abscess
Agressive antibiotic treatment
-Erythromycin
-Clindamycin
-metronidazole
-3rd generation cephalosporins |
|
|
Term
| What is the only anaerobic endospore-forming bacteria? |
|
Definition
|
|
Term
| What is responsible for Clostridia's pathogenesis? |
|
Definition
| Exotoxins and secreted hydrolytic enzymes |
|
|
Term
| What type of wound infections are caused by Clostridium perfringens that Diabetics are susceptible to? |
|
Definition
| Gas gangrene and anaerobic cellulitis |
|
|
Term
| How are wound infections from C. perfringens treated? |
|
Definition
Surgical Debridement - maggots to clear necrotic tissue
Massive doses of Penicillin |
|
|
Term
| What organism infection results from wound caused by rusty nail or other contaminated foreign object? |
|
Definition
|
|
Term
| What is the virulence factor of Clostridium tetani? what does it cause? |
|
Definition
Tetanospasmin - Exotoxin and neurotoxin
Causes Spastic contraction of muscles
-Rigid paralysis
-Trismus (lockjaw)
-Risus sardonicus
-Spasmodic contraction of back muscles
-Respiratory failure |
|
|
Term
| How does the exotoxin Tetanospamin function? |
|
Definition
Functions as a Zn metalloprotease that cuts a V-snare
-Vesicles cannot fuse
-Prevents release of inhibitory neurotransmitter, blocking postsynaptic inhibition of spinal motor reflexes |
|
|
Term
| What type of vaccine is there for Tetanus? |
|
Definition
| Toxoid vaccine - Formalin-inactivated tetanospasmin |
|
|
Term
| What organism is associated home-canned alkaline veggies? |
|
Definition
|
|
Term
| What foods should not be consumed by infants because of the risk of Clostridium botulinum? |
|
Definition
|
|
Term
| What are the toxins produced by C. botulinum? |
|
Definition
|
|
Term
| What is Classic foodborne botulism? |
|
Definition
Results of eating toxin-contaminated food
Spores germinate and vegetative cells make botulism toxin under anaerobic conditions. |
|
|
Term
|
Definition
Heat-labile
7 antigenic types
Metalloproteases that clip v- and/or t-SNARES
Prevents fusion of vesicles at NMJ
Inhibits release of Ach at NMJ |
|
|
Term
| What is the Botulism toxin encoded by? |
|
Definition
| lysogenic phage, plasmids, chromosome |
|
|
Term
| What does intoxication from botulism toxin result in? |
|
Definition
|
|
Term
| What are the symptoms of Botulism? |
|
Definition
Classic Triad:
1. Acute, symmetric, descending flaccid paralysis with prominent bulbar palsies. Begins with cranial nerves.
2. Absence of fever
3. Clear sensorium |
|
|
Term
| What is the treatment for botulism? |
|
Definition
Mechanical ventilation
Horse anti-botulism immunoglobulin (A, B, E serotypes) |
|
|
Term
| T/F Infant Botulism is an intoxication. |
|
Definition
FALSE
Infant Botulism is an infection
Results from consumption of spores, outgrowth of vegetative cells and production of toxin in the gut |
|
|
Term
| How is Clostridium difficile spread prevented? |
|
Definition
Use of soap and water rather than alcohol wipes for hand cleaning
(spores are resistant to alcohol) |
|
|
Term
| What type of infection is C. difficile? |
|
Definition
supra-infection
Causes Drug-induced diarrhea |
|
|
Term
| What are the 4 most common drugs that C. difficile is responsible for drug-associated diarrhea? |
|
Definition
imipenem
ceftaxidine
clindamycin
moxifloxacin |
|
|
Term
| What are the symptoms of C. difficile infection? |
|
Definition
Watery diarrhea - caused by enterotoxin
Fever
Drug-induced diarrhea can be bloody |
|
|
Term
| What is a serious sequela of C. difficile diarrhea? |
|
Definition
|
|
Term
| What toxins cause the symptoms of pseudomembranous colitis? |
|
Definition
|
|
Term
| What do Toxins A and B of C. difficile do? |
|
Definition
Function as monoglycosylate Rho-family GTPases
Intracellular signaling disrupted
Stress fibers rearranged
Results in leakage of fluids and severe inflammation |
|
|
Term
| How is C. difficile diagnosed? |
|
Definition
Detection of cytotoxic activity of Tox B from stools
RADT detection of Tox A and B in stools |
|
|
Term
| How is C. Difficile Treated? |
|
Definition
Discontinue antibiotics that induce diarrhea
Metronidazole 10+ days
Fecal material enema (gross) |
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