RESUMO
In vitro activity of dioxidin against pathogens of nosocomial infections and its cytotoxicity were estimated. The study involved 300 isolates from patients with nosocomial infections. The MICs of dioxidin were determined with the method of serial dilutions in broth. The dioxidin cytotoxicity was investigated with the MTI assay to assign the cell culture viability. In concentrations of 2 to 1024 meg/mi dioxidin was active against 279/300 (93%) strains. The drug inhibited the growth of all the gramnegative isolates. The highest activitywas observed against Enterobacteriaceae vs. nonfermenting gramnegative bacteria: the median, minimum and maximum MICs of dioxidin were 12 (4-32) and 32 (16-64) mcg/ml respectively. The dioxidin activity against gramnegative bacteria and fungi was lower. The MIC of dioxidin for 7/70 (10%) staphylococcal isolates, 9/28 (32%) enterococcal isolates and all the Candida isolates was > 1024 mcg/ml. The IC50 of dioxidin was 2.4+/-0.3 mM (low cytotoxicity). The results showed that the use of dioxidin as an antimicrobial for local application was advisable in the treatment of gramnegative bacterial infections provided adequate tissue concentrations were attained.
