Activity of Diphenyleneiodonium toward Multidrug-Resistant Strains.

Background/aims: The increased resistance of to antibiotics has increased the need to develop new treatments for this bacterium. The aim of our study was to identify new drugs with anti- activity.

Methods: We screened a small molecule library-the library of pharmacologically active compounds (LOPAC), which includes 1,280 pharmacologically active compounds-to identify inhibitors of growth. The minimal inhibitory concentrations (MICs) of antibiotics against multidrug-resistant strains were determined using the agar dilution method.

Results: We identified diphenyleneiodonium (DPI) as a novel anti- agent. The MIC values for DPI were ＜0.03 µg/mL against all tested strains. DPI also exhibited strong antibacterial activity against common gram-negative and gram-positive pathogenic bacteria.

Conclusions: DPI may be a candidate anti- drug for future development.