Antibacterial activities of nitrothiazole against Campylobacter jejuni and Campylobacter coli.

Niridazole (Ambilhar) and three other newly synthesized nitrothiazole derivatives were highly active against 19 microaerophilic campylobacters (minimum concentration required to inhibit 50% of strains [MIC50], 0.0075 to 0.015 mg/liter). There were, however, considerable differences in the susceptibility among strains tested, and one nitrothiazole derivative was rather inactive (MIC50, 2 mg/liter). Nitroimidazole derivatives, such as metronidazole and tinidazole, were less active (MIC50, 2 and 4 mg/liter, respectively). The nitrofuran derivatives, such as nitrofurazone and nitrofurantoin, were also less active (MIC50, 1 mg/liter). Niridazole and another potent nitrothiazole derivative killed the campylobacters rapidly at low concentrations. In contrast, much higher concentrations of metronidazole were required to achieve bactericidal values.