Year in review: Microbes exploit their killer
Triclosan promotes antibiotic resistance
Microbes have turned our pharmaceutical weapons into allies. This year, triclosan, an antimicrobial agent, topped the list of chemical traitors, aiding rather than deterring germs.
Leaked from products such as toothpaste and hand soap, low doses of triclosan promote drug resistance in germs that cause difficult-to-treat infections. In the environment, the chemical can disrupt hormone regulation in some animals, such as fish. (Data are lacking on health effects in humans.)
Despite the ongoing battle against antibiotic-resistant microbes (SN: 10/4/14, p. 22), triclosan remains omnipresent in household and personal care products. Humans take up the anti-microbial agent by ingesting it or absorbing it through skin. Washed down the drain, triclosan amasses in sewage and seeps into the environment.
Subscribe to Science News
Get great science journalism, from the most trusted source, delivered to your doorstep.
In wastewater treatment plants, triclosan can sabotage the microbial cleaners responsible for breaking down sewage, killing off some beneficial microbes and spurring drug resistance in others (SN: 7/26/14, p. 9).
Some of the 100 metric tons of triclosan that enters U.S. sewage plants each year lingers after treatment. Treated waste-water and sewage-based fertilizers can then spread the antimicrobial chemical. When such treated water is used on farmland, small amounts of triclosan accumulate in vegetables (SN Online: 9/19/14).
The U.S. Food and Drug Administration is reviewing the use of triclosan in personal care products. But some legislators and manufacturers aren’t waiting. In May, Minnesota banned triclosan from certain products, effective in 2017. And Johnson & Johnson and Procter & Gamble plan to remove the antimicrobial agent from their products.