VOA常速英语:Researchers Develop Method for Treating Chronic Infections

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Researchers are developing a way to treat chronic infections by destroying a tightly bound film that surrounds bacteria and makes them much harder to fight with antibiotics or the body's natural immune system.

Many infections, such as those that are responsible for chronic ear and sinus infections or diabetic foot ulcers, are difficult to treat because the bacteria have gathered together and formed a tightly-bound, protective layer called a biofilm.

"For example when you cross a river or a stream and you slip on a slimy rock, that is actually a biofilm," said Gord Froehlich.

The president of Kane Biotech in Canada, Gord Froehlich says bacteria covered by such a layer of biofilm are untouchable by antibiotics and the body's immune system.

Scientists say bacteria are easier to fight when they are floating around individually and have not formed such protective layers.

Biofilm expert David Davies and his colleagues at the State University of New York at Binghamton have discovered a chemical signal that tells bacteria it is time to break up into a free-floating, so-called planktonic state.

"It is sort of like if you were to go to a theater and shout "fire," all of the bacteria in a biofilm get up and leave from a specific location," said David Davies. "And so if we can incorporate this into a drug that we administer along with an antibiotic, we have been able to show in laboratory studies, that we can increase significantly the number of bacteria that are killed by the antibiotic."

Davies' research with biofilms is published this month in the Journal of Bacteriology.

Gord Froehlich of Kane Biotech says his company is poised to apply for U.S. regulatory approval of a biofilm cream that can be applied to chronic wounds such as a diabetic foot ulcer to help it heal.   

"This biofilm [that] forms over the wound prevents the antibiotic from doing its job," said Froehlich. "So, we developed [a] technology that actually attacks the biofilm, it attacks the house that bacteria live in, and exposing that bacteria to the antibiotic treatment."

The company is also working on another product that is like a giant bandage that contains a dispersal agent.

Researchers say a dispersal agent is not by itself lethal to microbes.  Products containing the agent simply make bacteria easier to kill with anti-biotics or by the body's immune system.