Salts of compounds according to formula (I), wherein X is selected from the group consisting of H2SO4, HSO3R, HSO3Ar, H3PO4, HCl, HBr, CF3CO2H and CCl3CO2H, are provided. The preferred salt is the p-toluene sulfonate. These compounds and their pharmaceutical compositions are useful as Fab1 inhibitors for treating bacterial infections.