Researchers have developed a new drug to fight one of the deadliest infections: Clostridium difficile. It didn't kill the bacteria and that's a good thing, the researchers report. It's not an antibiotic. Instead, it interferes with the toxic compounds made by the bug. A new drug to fight C. difficile is badly needed. C. difficile infections kill 29,000 Americans a year and make 450,000 sick. Right now, antibiotics can make patients even sicker because they kill not only the C. difficile, but so-called good bacteria that keep things in balance. Once they're killed off, "C. diff," as it's commonly known, can come back and even proliferate — without competition.