A nitrofuran antibiotic; active against laboratory strains of S. aureus, E. faecalis, and E. coli (MICs = 8 μg/ml for all) as well as clinical isolates of several urinary tract pathogens including Enterococcus, coagulase-negative staphylococci, Klebsiella, and P. mirabilis (MICs = 2-64 μg/ml); induces mutagenicity in mammalian and bacterial cell-based assays and carcinogenesis, reproductive effects, and toxicity in rats and mice (LD50s = 590 and 640 mg/kg, respectively)