Which gene type commonly mediates resistance to beta-lactam antibiotics such as penicillin?

Which gene type commonly mediates resistance to beta-lactam antibiotics such as penicillin?

• A. Efflux pumps
• B. Carbohydrate modification
• C. Beta-lactamase genes
• D. Capsule formation genes

Answer: (C)

Bacteria commonly resist beta-lactam antibiotics through enzymatic inactivation. Beta-lactams, like penicillin, disrupt cell wall synthesis by blocking penicillin-binding proteins. Bacteria counter this by producing beta-lactamase enzymes that break open the beta-lactam ring, instantly neutralizing the drug. The genes encoding these enzymes—beta-lactamase genes—are often carried on transferable elements, which helps resistance spread among bacteria. Other mechanisms, such as efflux pumps, can contribute to resistance in some contexts by pumping drugs out of the cell, but they are not the primary way penicillins are inactivated. Modifications to surface carbohydrates or capsule formation relate more to virulence or immune evasion than to directly disabling beta-lactam antibiotics.

Bacteria commonly resist beta-lactam antibiotics through enzymatic inactivation. Beta-lactams, like penicillin, disrupt cell wall synthesis by blocking penicillin-binding proteins. Bacteria counter this by producing beta-lactamase enzymes that break open the beta-lactam ring, instantly neutralizing the drug. The genes encoding these enzymes—beta-lactamase genes—are often carried on transferable elements, which helps resistance spread among bacteria.

Other mechanisms, such as efflux pumps, can contribute to resistance in some contexts by pumping drugs out of the cell, but they are not the primary way penicillins are inactivated. Modifications to surface carbohydrates or capsule formation relate more to virulence or immune evasion than to directly disabling beta-lactam antibiotics.