A hospital central supply needs to sterilize a batch of heat-sensitive plastic catheters and electrical equipment. They decide to use ethylene oxide gas. What is the primary mechanism by which ethylene oxide kills microorganisms?

• A Denaturation of proteins by hydrolysis
• B Disruption of cell membrane integrity
• C Oxidation of cellular enzymes
• D Alkylation of DNA and proteins ✓

Explanation

Ethylene oxide is an alkylating agent that replaces hydrogen atoms with alkyl groups in DNA and protein molecules, preventing normal cellular metabolism and replication. Denaturation by hydrolysis is the mechanism of moist heat. Oxidation is the mechanism of dry heat. Membrane disruption is typical of detergents and alcohols.

Reference: Ananthanarayan and Panicker's Textbook of Microbiology, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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