The most predominant causative agent of gas gangrene is?

UPPSC-2021

Applied Microbiology & Infection control

Easy

Appeared in: UPPSC-2021

Explanation

Clostridium perfringens is the most common bacterial species responsible for causing gas gangrene, accounting for the majority of cases.
It is a Gram-positive, anaerobic, spore-forming bacillus commonly found in soil, which can contaminate deep or crush wounds.
The bacterium produces potent exotoxins, notably alpha-toxin (lecithinase), which causes rapid and extensive muscle necrosis (myonecrosis) and tissue destruction.
A key feature of the infection is the production of gas within the tissues as a byproduct of fermentation, leading to crepitus, a hallmark clinical sign.

Option B: While various bacteria, including some Gram-negative bacilli, can cause wound infections and even gas formation, they are not the predominant or classic cause of true gas gangrene (clostridial myonecrosis).
Option C: This bacterium causes typhoid fever, a systemic illness transmitted through contaminated food and water that primarily affects the gastrointestinal system. It does not cause soft tissue infections like gangrene.
Option D: HIV (Human Immunodeficiency Virus) is a virus that attacks the immune system, leading to AIDS. It does not directly cause bacterial infections like gas gangrene, although individuals with advanced HIV may be more susceptible to various infections due to their compromised immune status.

Clinical Relevance

Nursing practice connection: Knowing Etiology of Gas Gangrene helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Recognizing the signs of gas gangrene is a critical nursing skill as it is a surgical emergency requiring immediate intervention to prevent sepsis, limb loss, and death.
Key nursing assessments include checking for crepitus (gas under the skin), severe pain out of proportion to the injury, foul-smelling discharge, and signs of systemic toxicity (fever, tachycardia, hypotension).
What if? If a patient with a deep, contaminated wound develops sudden, severe pain and swelling but no crepitus is felt yet, the nurse should still have a high suspicion for gas gangrene and notify the physician immediately, as crepitus may be a later sign and pain is often the first symptom.

How to Approach the Question

First, identify the key terms in the question: 'predominant causative agent' and 'gas gangrene'.
This is a factual recall question that tests your knowledge of microbiology and infectious diseases.
Access your knowledge about the specific pathogens that cause well-known conditions. Gas gangrene is classically linked to a specific genus of bacteria.
Evaluate each option. Salmonella typhi causes typhoid fever. HIV is a virus. Gram-negative bacilli is a broad category, not a specific agent.
Conclude that Clostridium perfringens is the specific, well-known pathogen responsible for most cases of gas gangrene.

Concept Tested & Keywords

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