Comparative in vitro activity of five nitrofurans.

Five nitrofurans- nitrofurantoin, nifuratel, nitrofurazone, furazolidone and and SQ 18,506--have been tested against 201 microbial strains. Escherichia coli, Streptococcus faecalis, micrococci and Staphylococcus epidermidis were sensitive to all five compounds; furazolidone and SQ 18,506 were the most active against these species. Klebsiella aerogenes was less sensitive, and Proteus spp., Providencia stuartii and Pseudomonas aeruginosa strains were resistant. Nifuratel was inhibitory for some Candida albicans strains, and SQ 18,506 was highly active against this species. Nifuratel was judged overall to have superior in vitro antimicrobial properties to nitrofurantoin.