Causative agent of peptic ulcer?

SGPGI Nursing Officer-2022

Applied Microbiology & Infection control

Easy

Appeared in: SGPGI Nursing Officer-2022

Explanation

Helicobacter pylori is a gram-negative bacterium strongly associated with peptic ulcer disease, infecting about 90% of patients with duodenal ulcers and 70% with gastric ulcers.
The bacterium's survival in the stomach is enabled by its production of the enzyme urease, which generates ammonia to neutralize gastric acid, creating a protective environment.
H. pylori burrows into the mucosal lining, provoking a local inflammatory response and releasing toxins (like CagA and VacA) that damage epithelial cells, leading to gastritis and ulcer formation.
Eradication of H. pylori with antibiotics is a cornerstone of treatment, leading to ulcer healing and significantly reducing the risk of recurrence.

Option B: Escherichia coli (E. coli) is a bacterium commonly found in the intestines. While certain strains can cause significant illness, it is primarily associated with urinary tract infections, traveler's diarrhea, and food poisoning, not peptic ulcers.
Option C: The term 'Staphylococcal' refers to infections caused by Staphylococcus bacteria. These organisms are major causes of skin infections (e.g., boils), wound infections, pneumonia, and food poisoning through toxin production. They do not cause peptic ulcers.
Option D: Staphylococci is the plural form for Staphylococcus. Like the 'Staphylococcal' option, this refers to a genus of bacteria not implicated in the formation of peptic ulcers. Their primary sites of infection are the skin, respiratory tract, and sites of toxin-mediated illness.

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 play a crucial role in educating patients with H. pylori-induced ulcers about the importance of completing the full course of antibiotics and proton pump inhibitors (PPIs) to ensure complete eradication and prevent recurrence.
Patient assessment should include screening for risk factors like chronic NSAID use, as this is the second most common cause of peptic ulcers and requires a different management approach (i.e., discontinuing the NSAID).
Nurses must teach patients to recognize signs of ulcer complications, such as black, tarry stools (melena) or vomiting blood/coffee-ground material (hematemesis), and to seek immediate medical attention if they occur.

How to Approach the Question

First, identify the core of the question, which is asking for the 'causative agent' of a specific condition, 'peptic ulcer'. This is a factual recall question.
Scan the options, which are all types of bacteria. This confirms you need to link a specific pathogen to the disease.
Recall or deduce the most common cause of peptic ulcers. H. pylori is famously associated with this condition in medical and nursing studies.
Analyze the provided image if available. The image shows a bacterium causing an ulcer, confirming the infectious nature of the condition and providing visual cues that match the known mechanism of H. pylori.
Eliminate the other options based on your knowledge of microbiology. E. coli is linked to GI/urinary infections, and Staphylococcus to skin/systemic infections, making them unlikely causes of stomach ulcers.

Concept Tested & Keywords

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