If the bacterium infects and overwhelms a patient, it can cause serious illness. In the United States alone, C. difficile costs more than $4 billion per year to treat.
Approximately 15,000 of the quarter-million people who are stricken annually die.
Antibiotics, which are used to disarm the bacterial infection, can also kill off beneficial microbes in the gut that normally keep C. difficile in check.
A drug called ebselen doesn’t actually kill C. difficile, but it prevents the release of toxins that cause tissue inflammation as well as life-threatening dehydration and diarrhea, said Matthew Bogyo, a pathology and microbiology professor at Stanford University in California.
“Basically, it shuts down the disease,” he said.
In experiments with mice, reported in the journal Science Translational Medicine, animals received C. difficile toxins treated with ebselen or plain, untreated toxins.
All of the rodents injected with the treated solution lived, while those in the untreated group died within two days.
The good news, Bogyo said, is that the compound appears to be safe in humans.
“It turned out to be an interesting lead compound, because it’s already in humans and it’s safe,” he said. “And even though it’s not a drug approved by the FDA yet, the fact that we know it can be put into humans without causing toxic side effects means it has a high chance of being a useful agent.”
Clinical trials of ebselen approved by the FDA are under way in the treatment of stroke and bipolar disorder.