The effects of chlorate- and streptomycin-resistance mutations on nitrofurantoin resistance in Escherichia coli K-12.
Chlorate-resistant mutants with none of the usual pleiotropic effects such as defective nitrate reductase activity were isolated from Escherichia coli K-12. These chlorate-resistant mutants (designated chlHW) did not yield strains with a high level of nitrofurantoin resistance following selection with nitrofurantoin. The chlorate-resistance mutation reduced the nitrofurantoin resistance of high-level mutants to an intermediate level. Further mutation to resistance to streptomycin and other aminoglycoside antibiotics suppressed the effect of chlHW on the level of nitrofurantoin resistance. Other chlorate-resistance genes examined did not have the same effect on nitrofurantoin resistance as chlHW. The gene was cotransducible (Pl) with intermediate-level nitrofurantoin resistance and proC. It is suggested that the chlHW mutation may enhance the accumulation of nitrofurantoin inside the cell since it is known that a multiple aminoglycoside-resistance mutation with pleiotropic effects on the cell membrane can also confer high-level resistance to nitrofurantoin.
D002704:Chlorates / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D009154:Mutation; D009582:Nitrofurantoin / Q000494:pharmacology*; D013307:Streptomycin / Q000494:pharmacology*
D002704:Chlorates; D009582:Nitrofurantoin; D013307:Streptomycin