Helicobacter Flashcards
What are the characteristics of Helicobacter?
Spiral-shaped or curved, flagellated, gram negative.
Where are Helicobacter spp. found?
Associated with GI tract of humans and animals.
What diseases does H. pylori cause?
Persistent gastritis, Peptic ulcer disease, Gastric adenocarcinoma. Gastric mucosal-associated lymphoma
T/F. In animals, Helicobacter related disease spectrum of various species is only asymptomatic.
False. Asymptomatic to gastritis to cancer.
Which of the following is NOT correctly matched with the virulence factors with its description with Helicobacter? (Choose 2)
A. Flagella - provide motility for penetrations of mucus and adherence to gastric epithelia.
B. Urease - Hydrolyzes urea to alkaloids (alkaloids neutralize gastric acids).
C. Adhesins - sialic acid-binding adhesin; blood group antigen-binding adhesin.
D. LPS - endotoxin, O-repeats prevent complement attachment.
E. Cytotoxin associated gene pathogenicity island - codes for T4SS.
F. Vacuolating Cytotoxin - disrupts epithelial cell barrier; pro-inflammatry.
G. Cytolethal Distending Toxin - similar to that from Mycobacterium.
B. Urease - Hydrolyzes urea to alkaloids (alkaloids neutralize gastric acids).
G. Cytolethal Distending Toxin - similar to that from Mycobacterium.
CORRECT:
Urease - hydrolyzes urea to ammonium (ammonium neutralizes gastric acids)
Cytolethal Distending Toxin (CDT) - similar to that from C. Jejuni (KNOW THIS!)
What are the growth characteristics of Helicobacter?
Microaerophilic, optimal growth at 37C, flat, non-segmented, non-hemolytic colonies, slow growing, fastidious (selective media)!
Similar to Campyolobacter and difficult to culture!
Which of the following is FALSE concerning reservoirs of Helicobacter?
A. Gastric mucus layer of many animals.
B. >50% of humans carry H. pylori (vary with diet/regions).
C. 80-100% of horses are infected with at least one Helicobacter species.
D. 60% of slaughtered pigs infected with H. suis.
C. 80-100% of DOGS are infected with at least one Helicobacter species.
How is Helicobacter transmitted?
Oral-oral or Oral-fecal (Bateriologists aren’t sure.. wtf!)
T/F. Helicobacter has a zoonotic potential because some evidence show that humans and their pets are infected with similar strains.
True.
Dr. Murphy thinks it’s oral-oral between humans and their pets.. and he says he’ll leave this up to your imagination
What is the pathogenesis of Helicobacter?
Not understood.
Organism alters gastric physiology (urease), adjusts gastric environment for persistence/colonization.
T/F. Helicobacter causes acute inflammation.
False. CHRONIC!
What are some pathological changes that are caused by Helicobacter?
Primary importance: STOMACH PROBLEMS
Gastric pathological changes: hyperlpasia, reduction of mucus, degeneration of glands, necrosis, inflammation.
Hepatic: inflammatory and necrotizing lesions.
What are the laboratory diagnosis used for Helicobacter?
Stained smears of gastric mucosa (difficult), urease test, culture (difficult), molecular methods (PCR, Western Blot, FISH: fluorescence in situ hybridization).
What are treatments and control for Helicobacter?
Controversial (infections are subclinical).
Resistance to antimicrobials (quick).
Combination therapies (Amoxi + metronidazole, Amoxi + Clarithromycin, Bismuth subsalicylate, omeprazole or famotidine)
BASICALLY PEPTO!
T/F. Helicobacter was originally classified as Campylobacter.
True
