A patient with a traumatic wound infection yields Clostridium perfringens on culture. On blood agar, this organism characteristically exhibits which pattern of hemolysis?

• A Alpha hemolysis
• B Beta hemolysis
• C Gamma hemolysis
• D Double zone of hemolysis ✓

Explanation

Clostridium perfringens produces a double zone of hemolysis on blood agar. The inner zone of complete hemolysis is due to theta toxin, and the outer zone of incomplete hemolysis is due to alpha toxin. Alpha hemolysis is seen in Streptococcus pneumoniae. Beta hemolysis is seen in Streptococcus pyogenes. Gamma hemolysis indicates no hemolysis.

Reference: Ananthanarayan and Panicker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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