Mutagenicity of nitrofuran drugs in bacterial systems.

The mutagenic activity of 5 nitrofuran drugs (furadantin, furoxon, furacin, benzazon VII and lampit) was tested on strains Salmonella typhimurium TA 100, TA 1535, TA 1438 and Escherichia coli WP2 uvrA+ and WP2 wrA. All nitrofurans tested has a marked mutagenic effect on strain TA 100 and, partially, on strain TA 1535 except for furoxon which was strongly toxic for this strain. No significant mutagenic effects of the drugs were observed with strain TA 1538. With the exception of lympit, all drugs exerted a mutagenic action on E coli WP2 vwA but no on WP2 uvA+ which has an intact excision repair system. The only drug exerting a mutagenic effect on the latter strain was furoxon. All five nitrofurans exhibited a positive repair test. The results support the notion that the nitrofuran mutagens under study induce single base substitutions.