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Avoid Using Products With the Antimicrobial Triclosan

Many health professionals have warned for years that the antibacterial triclosan should be avoided. Triclosan is found in a large variety of personal and consumer products labeled "antibacterial" or "antimicrobial". Now a recent study gives another reason to avoid triclosan - it makes UTI (urinary tract infection) bacteria MORE resistant to antibiotics.

Scientists have been warning about triclosan (and related triclocarbon) for a while, and have asked that their use be restricted due to risks to human health, to wildlifeand its accumulation in water, land, wildlife, and humans. Not only do they persist in the environment, they are also a source of toxic and carcinogenic compounds including dioxins, chloroform, and chlorinated anilines. They are endocrine disruptors that bioaccumulate (build-up) in humans and wildlife. They are toxic to aquatic and other organisms, yet they are found in the majority of people and freshwater streams. In other words, the chemicals are all around us and in us!

More than 2000 personal and consumer products, as well as building materials, contain triclosan and triclocarban. For example, they are found in soaps, toothpastes, detergents, clothing, toys, carpets, plastics, kitchen items, and paints. According to the FDA, which is responsible for regulation of foods, drugs, cosmetics, medical devices, and similar products, there is no evidence that antibacterial soaps are more effective than nonantibacterial soap and water.

What should one do? Read labels and avoid products containing triclosan and other antimicrobials, and products labeled anti-odor, antibacterial, anti-germ, or containing Microban. No, you don't need antibacterial or anti-odor socks or cutting boards! See earlier posts on this topic (herehere, and here).

From Science Daily: Chemical 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 2017, the U.S. Food and Drug Administration cited both safety concerns and lack of efficacy when it recommended against adding triclosan to consumer soaps, but these guidelines have not discouraged companies from adding it to other products. What's more, Levin said, "Triclosan is very stable. It lingers in the body and in the environment for a long time."

Some antibiotics kill bacterial cells, while others keep them from growing. Levin and her colleagues were particularly interested in bactericidal antibiotics -- those that can kill bacterial cells and are typically prescribed by doctors to treat bacterial infections. They wanted to know whether triclosan could protect bacteria from death in the presence of killing antibiotics.

Corey Westfall, postdoctoral scholar in the Levin lab, treated bacterial cells with bactericidal antibiotics and tracked their ability to survive over time. In one group, the bacteria were exposed to triclosan prior to being given the bactericidal antibiotic. In the other group, they were not. "Triclosan increased the number of surviving bacterial cells substantially," Levin said. "Normally, one in a million cells survive antibiotics, and a functioning immune system can control them. But triclosan was shifting the number of cells. Instead of only one in a million bacteria surviving, one in 10 organisms survived after 20 hours. Now, the immune system is overwhelmed."

Triclosan exposure allowed the bacteria to escape death by antibiotics. And the protective property was not limited to any single family of antibiotics. In fact, multiple antibiotics that are considered unique in how they kill cells were less effective at killing bacteria exposed to triclosan.

UTIs occur when bacteria, primarily Escherichia coli (E. coli), enter and infect the urinary tract. Antibiotics such as Cipro are commonly used to kill the bacteria and treat the infection.

UTIs are common; so is exposure to triclosan. A shocking percentage -- about 75 percent -- of adults in the United States have detectable levels of triclosan in their urine. About 10 percent of adults have levels high enough to prevent E. coli from growing. Could triclosan's presence in the body interfere with treating UTIs?

Ana Flores-Mireles, an assistant professor at the University of Notre Dame, worked on this study as a postdoctoral scholar in the lab of Scott Hultgren, the Helen L. Stoever Professor of Molecular Microbiology at the School of Medicine. With the help of Jeffrey Henderson, associate professor of medicine and molecular biology, she figured out that mice which drink triclosan-spiked water have urine triclosan levels similar to those reported in humans. "This result meant we could actually test the impact that human urine levels of triclosan have during antibiotic treatment of UTIs in mice," Levin said.

All of the mice with the infection received Cipro to treat the UTI. Only some of the mice drank triclosan-spiked water. After antibiotic treatment, mice with triclosan exposure had a large number of bacteria in their urine and stuck to the bladder; mice without exposure had significantly lower bacterial counts.

"We found 100 times more bacteria in the urine of triclosan-treated mice -- that is a lot." This striking result has an equally striking message -- antibiotics are less effective at treating UTIs when triclosan is around, at least in mice. Triclosan is interfering with antibiotic treatment, but how? Levin and her colleagues found that triclosan works with a cell growth inhibitor, a small molecule nicknamed ppGpp, to render cells less sensitive to antibiotics.

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