磺胺噻唑钠盐是一种短效磺胺药。在发现毒性较小的替代品之前，它是一种常见的口服和局部抗生素。它不再在人类中使用。磺胺噻唑被添加到实验动物的饮食中，以抑制肠道细菌形成叶酸。这确保了动物唯一可利用的叶酸来源是从它们的饮食中获取的。磺胺噻唑是一种磺酰胺类抗生素，通过抑制二氢蝶呤合酶来阻止二氢叶酸的合成。磺胺噻唑是细菌对氨基苯甲酸（PABA）的竞争性抑制剂，而细菌对叶酸合成是必需的。它对革兰氏阳性菌，革兰氏阴性菌和衣原体具有活性。抗性模式是通过改变二氢蝶呤合酶或叶酸合成的替代途径。 Sulfathiazole sodium salt is a short-acting sulfa drug. It was a common oral and topical antibiotic until less toxic alternatives were discovered. It is no longer used in humans. Sulfathiazole is added to the diet of laboratory animals to inhibit folate formation by gut bacteria. This ensures that the animal′s only source of available folate is from their diet. Sulfathiazole is a sulfonamide antibiotic that blocks the synthesis of dihydrofolic acid by inhibiting the enzyme dihydropteroate synthase. Sulfathiazole is a competitive inhibitor of bacterial para-aminobenzoic acid (PABA), which is required for bacterial synthesis of folic acid. It is active against Gram positive bacteria, Gram negative bacteria and Chlamydia. Mode of resistance is via the alteration of dihydropteroate synthase or alternative pathway for folic acid synthesis.