In vitro activity of DS-2969b and comparator antimicrobial agents against Clostridioides (Clostridium) difficile, methicillin-resistant Staphylococcus aureus, and other anaerobic bacteria.

The in vitro activity of DS-2969b, a novel GyrB inhibitor, and six comparator agents was studied against 101 recent North American Clostridioides difficile isolates, 46 other intestinal anaerobes and 51 strains of methicillin-resistant Staphylococcus aureus. The MIC ranges (MIC90s) of DS-2969b against C. difficile and S. aureus were 0.03-0.125 (0.125) µg/ml and 0.125-1 (0.5) µg/ml, respectively. DS-2969b showed the greatest activity of the agents tested. There was no difference in MICs of DS-2969b among different ribotypes.