A nurse should screen clients of childbearing age for pregnancy as the administration of which of the following vaccines is contraindicated during pregnancy?

Choice A rationale:

Bacteriostatic. Sulfonamides are a class of antibiotics that work primarily as bacteriostatic agents. They inhibit the growth and reproduction of bacteria by blocking the synthesis of folic acid, which is essential for bacterial DNA and RNA synthesis. By slowing down bacterial growth, sulfonamides give the body's immune system a chance to eliminate the bacteria. Bacteriostatic antibiotics do not directly kill bacteria but rather impede their ability to multiply. This action is a key characteristic of sulfonamides.

Choice B rationale:

Bactericidal. Sulfonamides are not primarily bactericidal. Bactericidal antibiotics directly kill bacteria by disrupting their cell walls, protein synthesis, or other essential processes. Sulfonamides do not have this direct killing effect. They work by inhibiting folic acid synthesis and, as a result, slowing down bacterial growth. While this can eventually lead to bacterial death, the primary action of sulfonamides is bacteriostatic.

Choice C rationale:

Promotor of folic acid activity. This choice is not accurate. Sulfonamides do not promote folic acid activity; rather, they inhibit it. Sulfonamides are structural analogs of para-aminobenzoic acid (PABA), a precursor necessary for folic acid synthesis in bacteria. By competing with PABA, sulfonamides disrupt folic acid production in bacteria, ultimately leading to growth inhibition. Therefore, they are not promoters of folic acid activity.

Choice D rationale:

Bacterial cell metabolizer. Sulfonamides do not metabolize bacterial cells. Instead, they interfere with bacterial metabolism by blocking the synthesis of folic acid. This disruption affects the DNA and RNA synthesis of bacteria, which rely on folic acid derivatives. The primary action of sulfonamides is to inhibit this metabolic pathway, not to metabolize bacterial cells.