Which organism is associated with gas gangrene, known for stormy fermentation and double-zone beta-hemolysis on anaerobic culture?

Which organism is associated with gas gangrene, known for stormy fermentation and double-zone beta-hemolysis on anaerobic culture?

• A. Clostridium perfringens
• B. Staphylococcus aureus
• C. Streptococcus pyogenes
• D. Bacillus cereus

Answer: (A)

Gas gangrene is classically caused by an anaerobic, spore-forming bacterium that ferments tissue sugars rapidly, producing gas and causing tissue destruction and crepitus. On anaerobic culture, this organism shows a distinctive two-zone pattern of beta-hemolysis on blood agar: an outer zone of complete hemolysis with an inner zone of partial hemolysis. This combination—gas production in infected tissue and the double-zone beta-hemolysis on anaerobic culture—is characteristic of Clostridium perfringens. The other organisms listed are not typically associated with gas gangrene or with this specific hemolysis pattern; Staphylococcus aureus and Streptococcus pyogenes can be beta-hemolytic but are not anaerobic pathogens causing gas gangrene, and Bacillus cereus does not produce the same anaerobic, gas-producing, double-zone hemolysis profile.

Gas gangrene is classically caused by an anaerobic, spore-forming bacterium that ferments tissue sugars rapidly, producing gas and causing tissue destruction and crepitus. On anaerobic culture, this organism shows a distinctive two-zone pattern of beta-hemolysis on blood agar: an outer zone of complete hemolysis with an inner zone of partial hemolysis. This combination—gas production in infected tissue and the double-zone beta-hemolysis on anaerobic culture—is characteristic of Clostridium perfringens. The other organisms listed are not typically associated with gas gangrene or with this specific hemolysis pattern; Staphylococcus aureus and Streptococcus pyogenes can be beta-hemolytic but are not anaerobic pathogens causing gas gangrene, and Bacillus cereus does not produce the same anaerobic, gas-producing, double-zone hemolysis profile.