Sulfonamides Quiz

Sulfonamides

• Inhibit bacterial folate synthesis, which is essential for DNA production.
• Sulfonamide-susceptible organisms, unlike mammals, cannot use exogenous folate and must synthesize it from PABA.

Spectrum of Activity

• Inhibit Gram-positive bacteria, such as Staphylococcus.
• Inhibit Gram-negative bacteria, including Escherichia coli, Klebsiella pneumoniae, Salmonella, Shigella, and Enterobacter.
• Inhibit Nocardia, Chlamydia trachomatis, and some protozoa.
• Have poor activity against anaerobes.
• Pseudomonas aeruginosa is intrinsically resistant to sulfonamide antibiotics.

Mechanism of Action

• Act as PABA analogues.
• Inhibit dihydropteroate synthase, which is necessary for folate production within bacteria.
• Mammalian cells, which depend on exogenous sources of folate, are not affected.

Resistance to Sulfonamides

• May occur due to mutations that:
  • Cause overproduction of PABA.
  • Cause production of a folic acid synthesizing enzyme with low affinity for sulfonamides.
  • Impair permeability to the sulfonamide.

Classification of Sulfonamides

• Classified into three categories:
  • Oral absorbable.
  • Oral non-absorbable.
  • Topical.

Test your knowledge of sulfonamides and related compounds with this quiz. Explore the mechanism of action, spectrum of activity, and properties of these bacteriostatic agents that inhibit bacterial folate synthesis.