Toothbrushes and shower heads are full of viruses.

Rainforests and coral reefs aside, the bathroom is home to the latest hotspot offering awe-inspiring biodiversity.

In a new Northwestern-led study, microbiologists have discovered that showerheads and toothbrushes are teeming with an incredibly diverse collection of viruses, most of which have never been seen before. .

This may sound creepy, but the good news is that these viruses don't target humans. They target bacteria.

The microorganisms collected in the study are bacteriophages, or “phages,” a type of virus that infects and replicates inside bacteria. Researchers know little about phages, but recently phages attracted attention This is because it may be used to treat antibiotic-resistant bacterial infections. And previously unknown viruses lurking in our bathrooms could be a treasure trove of material for exploring their applications.

“The number of viruses we found is completely wild,” Northwestern University said. Erica M. Hartman The study was published in the journal Frontiers in Microbiomes. “We've discovered many viruses that we know little about and that we've never seen before. It's amazing how much untapped biodiversity there is around us. We don't even have to go far to find it; it's right under our noses.”

Hartman, an indoor microbiologist, is an associate professor of civil and environmental engineering at Northwestern University. McCormick School of Engineering with members of Synthetic Biology Center.

The return of “Operation Potimas”

The new study is an outgrowth of previous work in which Hartman and colleagues at the University of Colorado Boulder characterized the bacteria. living with a toothbrush and shower head. In previous studies, researchers asked people to submit swabs containing samples taken from used toothbrushes and showerheads.

Inspired by concerns that flushing toilets could generate clouds of aerosol particles, Hartman affectionately called this toothbrush research “Operation Pottymouth.”

“This project started out of curiosity,” Hartman said. “We wanted to know what kind of microorganisms live inside our homes. When we think about the indoor environment, surfaces such as tables and walls are extremely inhospitable places for microorganisms. Microorganisms live in environments with water. And where is the water? In the shower head and on the toothbrush.

What they discovered: 'The incredible diversity of viruses'

After characterizing the bacteria, Hartman used DNA sequencing to examine viruses living in the same samples. She was immediately shocked. In total, the samples contained more than 600 different viruses, and no two samples were the same.

“Basically, we didn't see any overlap in virus types between showerheads and toothbrushes,” Hartman said. “We also saw very little overlap between the two samples. Each showerhead and each toothbrush are like their own little islands. It emphasizes diversity.”

those who fight potential pathogens

Although they found few patterns across all the samples, Hartman and her team noticed more mycobacteriophages than any other type of phage. Mycobacteriophages infect mycobacteria, pathogenic species that cause diseases such as leprosy, tuberculosis, and chronic lung infections. Hartman envisions that one day researchers will be able to use mycobacteriophages to treat these and other infections.

“You can imagine taking these mycobacteriophages and using them as a way to remove pathogens from plumbing systems,” she said. “We want to look at all the capabilities these viruses might have and think about how we can exploit them.”

Avoid overreacting: Most microorganisms “don't make us sick”

But in the meantime, Hartman warns people not to worry about the invisible wildlife living in their bathrooms. Instead of using bleach, you can also soak your shower head in vinegar to remove calcium buildup or wash it with plain soap and water. And you should replace your toothbrush head regularly, Hartman says. Hartman also doesn't like antibacterial toothbrushes because they can lead to antibiotic-resistant bugs.

“Microorganisms are everywhere, but most of them don't make us sick,” she said. “The more we attack them with disinfectants, the more likely they are to become resistant or difficult to treat. We should all just accept them.”