Effects of nitrofurantoin on viability, DNA synthesis and morphology of Vibrio cholerae cells.

Nitrofurantoin caused a dose dependent inhibition of growth and decrease in viability of V. cholerae cells, the 10% (D10) and 37% (D37) survival doses being 50 and 19 micrograms/ml respectively. The drug at a concentration of 60 micrograms/ml caused 86% inhibition of DNA synthesis. Both light and electron microscopic observations revealed that treatment with nitrofurantoin (60 micrograms/ml for 1 hr at 37 degrees C) led to a significant filamentation of the V. cholerae cells, ultrastructure of the cell cytoplasm, plasma membrane and cell wall however remaining unaltered from those of untreated cells. The results are discussed in relation to DNA lesions produced by and the carcinogenic potential of the drug.