Question
Organism shown in the Photograph can cause all of the following EXCEPT
A. Peptic ulcer
B. Maltoma
C. Gastric carcinoma
D. Carcinoid tumor
Show Answer
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Correct Answer » D Explanation |
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Ans:D. Carcinoid tumor
Organism shown: Helicobacter pylori
HELICOBACTER PYLORI
- Gram negative, spiral rod.
- Motility. H. pylori has four to six flagella at the same spot.
- Grows under microaerophilic conditions with 5-20% CO2
- Produce oxidase, catalase, phosphatase, H2S and abundant urease
- The sole source of H pylori is human gastric mucus; transmission is likely to be oral-oral or fecal-oral
- Bacteria are present deep in the mucus near epithelial surface and do not invade the mucosa
- Gastric antrum is the commonest site of localization; infection is strictly confined to gastric mucosa and in areas of gastric metaplasia and heterotopias in the duodenum
- Virulence associated with cag(cytotoxin associated gene) and vac(vacoulating cytotoxin gene).
- The prevalence of H. pylori is approx. 30% in U.S. and other developed countries as against > 80% in most developing countries
- Worldwide, >80% of duodenal ulcers and >60% of gastric ulcers are related to H. pylori colonization
Infection may lead to following GIT pathologies:
- Acute gastritis
- Chronic gastritis
- Peptic ulcers (10-20% life time risk )
- Duodenal ulcers
- Colorectal polyps and colorectal cancer.
- Adenocarcinoma of distal (noncardia) stomach
- MALT lymphomas
- Gastric B cell lymphoma
- Autoimmune gastritis.
