Genes & Cells

Traditional medicine helps give the slip to bacteria, plus insulin insensitivity and dental plaque in this week's news

Traditional medicine makes nonstick bacteria
A common ingredient in Chinese anti-inflammatory medications can keep certain bacteria from glomming onto silicon rubber and many plastic surfaces. The chemical, called PGG, puts a stop to the formation of gooey bacterial colonies called biofilms, a team of researchers in Taiwan reports in the March Antimicrobial Agents and Chemotherapy.  In fact, low concentrations of this traditional medication can block 93 percent of biofilm construction. Like Silly Putty, these porridgy colonies fasten to an array of surfaces in hospitals, spreading infections among patients. PGG, which is taken from geraniums, could make a good antimicrobial coating for catheters and other medical devices. —Daniel Strain

MicroRNA breeds insulin insensitivity
A genetic molecule called microRNA-143 is responsible for insulin insensitivity in mice, and probably in humans with type 2 diabetes, researchers from Germany and Finland report in a paper published online March 27 in Nature Cell Biology. Insulin relays a signal to eat more glucose through a series of messenger proteins. The team discovered that higher than normal levels of miR-143 trips up a messenger — a protein called AKT — at an important leg of the relay, so that insulin’s message never reaches its destination. Lowering levels of the microRNA might fix the problem. —Tina Hesman Saey

Bacteria fight dental plaque
Friendly bacteria living on the tongue and cheeks can help fight buildup of dental plaque. The friendly bacteria, called Streptococcus salivarius, can stop bacteria associated with tooth decay from coating teeth in an organized community known as a biofilm. The species’ plaque-fighting capabilities come from a sugar-cleaving enzyme called FruA, researchers in Japan report in the March Applied and Environmental Microbiology. When people eat starchy or sugary foods containing fructose, such as fruit or soda, the bacteria make lots of FruA. FruA then chops up the sugars into more easily digested ones, but in the process robs plaque-forming bacteria of substances needed for forming biofilms. —Tina Hesman Saey

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