AIIMS Delhi NO - 2017
Applied Microbiology & Infection control
Easy

Most common causative organism of Peptic ulcer?

Appeared in: AIIMS Delhi NO - 2017

Explanation

  • Helicobacter pylori is a gram-negative bacterium recognized as the primary cause of peptic ulcer disease.
  • It colonizes the gastric mucosa, weakening the protective mucous layer through inflammation and enzyme production (e.g., urease).
  • This damage allows stomach acid to erode the underlying tissue, leading to the formation of ulcers in the stomach or duodenum.
  • Medical literature confirms that H. pylori is responsible for about 90% of duodenal ulcers and 70% of gastric ulcers.

Why Other Options Were Wrong

  • Option B: Escherichia coli is a bacterium commonly found in the intestines. While certain strains can cause severe diarrhea and gastroenteritis, it is primarily known for causing urinary tract infections and is not a causative agent for peptic ulcers.
  • Option C: Streptococcus is a genus of bacteria responsible for a wide range of infections, most notably streptococcal pharyngitis (strep throat), pneumonia, and skin infections like cellulitis. It does not cause peptic ulcers.
  • Option D: Botulism is a rare but serious paralytic illness caused by a neurotoxin produced by the bacterium Clostridium botulinum. It is typically associated with improper food canning and has no connection to the formation of peptic ulcers.

Related Visual

Visual explanation — Related Visual
Clinical Relevance
  • Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Peptic Ulcer Disease as background academic context rather than a clinical decision trigger.
  • Nurses are crucial in educating patients diagnosed with H. pylori-induced ulcers about the importance of adhering to the prescribed 'triple therapy' (two antibiotics and a proton pump inhibitor) to ensure complete eradication of the bacteria.
  • Accurate assessment for peptic ulcer disease includes asking about risk factors like chronic NSAID use, smoking, and symptoms such as epigastric pain that may be relieved by food.
  • Confirming the success of eradication therapy, often through a urea breath test or stool antigen test, is a key nursing consideration to prevent ulcer recurrence and complications like bleeding or perforation.
How to Approach the Question
  • First, identify the keywords in the question: 'most common', 'causative organism', and 'peptic ulcer'. This is a factual recall question asking for the primary pathogen.
  • Recall the major causes of peptic ulcer disease. The two most significant are a specific bacterial infection and the use of certain medications.
  • Evaluate each option based on your medical knowledge.
  • Helicobacter pylori is widely known as the bacterium strongly linked to peptic ulcers.
  • E. coli, Streptococcus, and Botulism are pathogens, but they are associated with different conditions (UTIs/diarrhea, throat/skin infections, and paralysis, respectively).
  • Conclude that H. pylori is the only option that is a common cause of peptic ulcers.
Concept Tested & Keywords
  • Concept Tested: Etiology of Peptic Ulcer Disease
  • Stem keywords: Most common, causative organism, Peptic ulcer
  • Lead-in keywords: Most common

Question ID

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Reference Book

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 88-90

E6 Medicine Davidson Principles Practice 24e p. 818-820

E6 Medicine Harrison 22e Part 1 p. 1339-1341

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