What is the action of Alcohol on Gram-positive and Gram-negative bacteria; Residual activity?

What is the action of Alcohol on Gram-positive and Gram-negative bacteria; Residual activity?

• A. Excellent; Excellent; Little
• B. Good; Excellent; Little
• C. Excellent; Good; Little
• D. Good; Good; Little

Answer: (A)

Alcohols act by rapidly denaturing proteins and disrupting lipid membranes, causing quick bacterial death. This mechanism doesn’t rely on differences between Gram-positive and Gram-negative cell walls, so both types are killed effectively and promptly. After application, alcohols evaporate quickly, leaving little to no persistent antimicrobial effect on the skin, which is why residual activity is described as little. In practice, alcohol is an excellent immediate antiseptic for both groups, but it provides minimal lasting activity unless paired with another agent that has persistent action (like chlorhexidine).

Alcohols act by rapidly denaturing proteins and disrupting lipid membranes, causing quick bacterial death. This mechanism doesn’t rely on differences between Gram-positive and Gram-negative cell walls, so both types are killed effectively and promptly. After application, alcohols evaporate quickly, leaving little to no persistent antimicrobial effect on the skin, which is why residual activity is described as little. In practice, alcohol is an excellent immediate antiseptic for both groups, but it provides minimal lasting activity unless paired with another agent that has persistent action (like chlorhexidine).