Bacteria from yogurt may prevent HIV

The scientists have come up with a novel delivery system for anti-AIDS drugs: milk-curdling bacteria used to make yogurt and cheese. They say the results offer hope for a microbicide that can prevent the spread of HIV, which now affects approximately 40 million people.

“We’ve found that you can engineer these bugs to secrete drugs – in this case, a viricide that disables HIV,” said Bharat Ramratnam, assistant professor of medicine at Brown Medical School and attending physician at Rhode Island Hospital. “The hope is to use the bacteria as the basis for a microbicide which can prevent sexual transmission of HIV.”

Using blasts of electric current, the team made tiny holes in lactic acid bacteria (LAB) membranes and inserted circular bits of DNA that carry the recipe for producing an HIV blocking protein called cynovirin. The team succeeded in producing a genetically modified LAB capable of producing cynovirin.

They now hope to use these bioengineered bacteria as the active ingredient in a microbicide (a foam, cream or suppository that can be applied to the vagina or anus before sex to prevent HIV transmission). Scientists around the world are trying to develop these topical drugs as weapons in the battle against HIV/AIDS.

The researchers expect to be able to test a new treatment in humans in three years time. A microbicide using modified LAB will be tested in monkeys beginning this summer.

“Before we can move into human trials, we need to meet a few challenges in animal trials,” Ramratnam said. “We need to be sure that LAB make enough cynovirin and make sure that the cynovirin is effective. If that happens, we may have a terrific treatment on our hands.”