Triclosan added to consumer products impairs response to antibiotic treatment

Grocery store aisles are stocked with products that promise to kill bacteria. People snap up those items to protect themselves from the germs that make them sick. However, new research from Washington University in St. Louis finds that a chemical that is supposed to kill bacteria is actually making them stronger and more capable of surviving antibiotic treatment. The study, available online Feb. 19 in the journal Antimicrobial Agents & Chemotherapy, suggests that triclosan exposure may inadvertently drive bacteria into a state in which they are able to tolerate normally lethal concentrations of antibiotics—including those antibiotics that are commonly used to treat urinary tract infections (UTIs). Triclosan is the active ingredient responsible for the "antibacterial" property marketed on many consumer products. It is added to toothpaste, mouthwash, cosmetics and even to clothing, baby toys and credit cards with the intention of reducing or preventing bacterial growth. "In order to effectively kill bacterial cells, triclosan is added to products at high concentrations," said Petra Levin, professor of biology in Arts & Sciences.