Indications for Nitrofurantoin Nitrofurantoin is active against common uropathogens, such as Escherichia coli Staphylococcus saprophyticus Enterococcus faecalis Other species of enterococci, including vancomycin - resistant strains, and Klebsiella and Enterobacter species are often less susceptible, but nitrofurantoin may still be effective in treating uncomplicated cystitis caused by these pathogens.