Effect of oral niridazole treatment on some bacterial infections in mice.

Treatment of specific-pathogen-free CD-1 mice with oral doses of 10 or 100 mg of niridazole per kg of body weight given 24 h before challenge and then every other day for up to 15 days altered the growth curves for Listeria monocytogenes, Mycobacterium bovis (BCG Montreal), M. tuberculosis H37Rv, and Salmonella enteritidis seen in the livers and spleens of the treated animals. Niridazole in an oral dosage of 10 mg/kg reduced (but did not eliminate) tuberculin hypersensitivity in the mycobacteria-infected mice. Both delayed hypersensitivity and antimycobacterial resistance quickly returned to normal levels once the drug treatment was stopped. Niridazole treatment reduced the growth of S. enteritidis in both intravenously and intragastrically challenged mice; this seemed to be due to the antibacterial action of the drug on the salmonellae both in vitro and in vivo.