Your toothbrush is full of hundreds of viruses

Hundreds of viruses that infect bacteria have been found on toothbrushes and showerheads. However, this is not a cause for concern as the virus is not harmful to humans and studying how it works may reveal new ways to kill drug-resistant bacteria.

We already know that our toothbrushes and shower heads are full of bacteria from our mouths and water supplies. However, little is known about the viruses that are also present on these surfaces.

To get a better picture, Erica Hartman and colleagues at Northwestern University in Illinois wiped down 92 showerheads and 36 toothbrushes from the bathrooms of people living in the United States.

By analyzing the DNA sequences of swab samples, researchers discovered more than 600 viruses known to infect bacteria called bacteriophages. Most viruses that are harmless to humans originate from toothbrushes, and many have never been reported before. “This is a crazy story, and it just highlights how much novelty there is out there,” Hartman said.

Although the researchers did not test whether viruses affected the thousands of bacteria they also discovered, Hartman said bacteriophages tend to do one of two things. They can hijack the bacteria’s molecular machinery to make copies of themselves and kill the bacteria as they exit. Alternatively, they can be integrated into the bacterial genome and change the bacteria’s behavior.

The bacteriophages identified by Hartman and colleagues are likely present on moist surfaces around the house, such as inside sinks and refrigerators. “We expect them everywhere,” she says.

“This is an interesting resource that allows us to better understand the breadth and detail of phage activity in the home,” says Jack Gilbert, a professor at the University of California, San Diego.

Dirk Bockmuhl of Germany’s Rheinwaal University of Applied Sciences said the discovery of so many new bacteriophages could lead to further They say it could point the way to a cure.