About 100 drugs already approved by the U.S. Food and Drug Administration (FDA) for other purposes can also prevent the growth of certain bacterial pathogens inside human cells, including those that cause Legionnaires' disease, brucellosis, and Mediterranean spotted fever. The findings, published in mBio, the online open-access journal of the American Society for Microbiology, demonstrate a new way of identifying non-antibiotic drugs that could one day help curb bacterial infections.
A handful of drugs on the list inhibit the growth of at least three of the four bacterial organisms tested. Those drugs include familiar compounds like loperamide, an antidiarrheal medication sold under the brand name Imodium and clemastine, an allergy medicine sold as Tavist, as well as drugs used to treat high blood pressure and angina.
Howard Shuman, professor of microbiology at the University of Chicago and a senior author on the study cautions that this study only looked at infection in the laboratory dish and therefore whether the drugs would effectively treat infections in humans is not known. The work, he says, is a good first step showing this method can identify FDA-approved drugs that might potentially act alongside traditional antibiotics.
"Antibiotic therapy is becoming more difficult to achieve, so looking for alternatives is always a good thing to do," Shuman says.
Shuman and his colleagues thought that certain types of bacteriathose that infect human cells and then replicate inside those cellsmight be vulnerable to other drug approaches.
"Intracellular bacteria resemble viruses in that they need host cell functions to complete their life cycle," says Shuman. So the researchers screened drugs to look for compounds that interfered with those cellular processes. They chose a panel of 640 FDA-approved drugs that have known safety and side effect profiles.
The researchers measured each drug's ability to d
|Contact: Jim Sliwa|
American Society for Microbiology