NITROFURAN DERIVATIVES AS RADIOMIMETIC AGENTS: CROSS-RESISTANCE STUDIES WITH ESCHERICHIA COLI

Mutants of Escherichia coli B selected on the basis of resistance to nitrofurazone, NFT, or ultraviolet light proved to be resistant to all three of these agents. Further tests showed that these mutants are also resistant to three other nitrofuran derivatives, nitrofurantoin, nihydrazone, and furazolidone, but not to nifuroxime. The mutants are also resistant to the chemically dissimilar radiomimetic agent, proflavin. Strain B and all the mutants derived from it are equally sensitive to streptomycin, a non-radiomimetic antibiotic. E. coli strain B/r (resistant to radiation and radiomimetic chemicals) shows the same resistance pattern as the new mutant strains. The results are discussed in terms of what is known concerning the basis for the resistance of strain B/r to ultraviolet light. It is concluded that radiomimetic nitrofurans probably exert their effect on E. coli through damage to DNA.