Viruses on bathroom staples: A new frontier in medicine

Scientists from Northwestern University discovered more than 600 types of viruses that infect bacteria. They thoroughly examined toothbrushes and showerheads in the bathrooms. Some of these viruses were previously unknown. This discovery is not alarming; it presents an opportunity for potential advancements in human medicine.

The journal Frontiers in Microbiomes reports that over 600 types of viruses that infect bacteria (bacteriophages), many previously unknown, were found on toothbrushes and showerheads.

Researchers have long known that toothbrushes and showerheads can harbour many bacteria from users' mouths and municipal water systems. However, little was known about the presence of "bathroom" viruses.

Previous studies suggesting that flushing a toilet produces aerosols that carry bacteria inspired further research. These findings prompted Erica Hartmann from Northwestern University in Illinois to conduct new research. The research team collected samples from 92 showerheads and 36 toothbrushes in the bathrooms of people living in the USA.

Using DNA sequencing methods, researchers discovered that over 600 types of bacteriophages — viruses that infect bacteria — live on these surfaces. Interestingly, the vast majority of them were discovered on toothbrushes. It was fascinating to find that almost every toothbrush tested was a habitat for different viruses.

Bacteriophages are viruses that infect bacteria but are harmless to humans. These viruses exhibit two mechanisms of action. They can take control of bacteria, leading to the creation of copies of themselves and subsequently killing the host, or they integrate into the bacteria's genome, altering their behaviour. Scientists believe that studying bacteriophages may open up new methods to combat antibiotic-resistant bacteria.

The more you attack them with disinfectants, the more they are likely to develop resistance or become more difficult to treat. We should all just embrace them — said Erica Hartmann.

The researchers were particularly interested in mycobacteriophages, viruses that infect mycobacteria, such as those responsible for tuberculosis, leprosy, or chronic lung infections. Scientists hope that in the future, mycobacteriophages can be used to treat these dangerous infections and to clean water supply systems of hazardous pathogens.

The discovered bacteriophages likely occur in homes, not only in bathrooms but also on other damp surfaces such as sinks or fridge interiors. However, researchers reassure that most of them are harmless.

There is no need to use aggressive disinfectants like bleach. To maintain showerheads, they can be submerged in vinegar to remove limescale or simply cleaned with soap and water. However, it is important to change toothbrushes regularly.

The research by scientists from Northwestern University in Illinois sheds new light on the invisible world of microorganisms present in our homes. However, although microbes are commonly present, they rarely cause diseases. Excessive use of disinfectants may encourage the development of resistance in bacteria and various pathogens, making them harder to combat with antibiotics, which poses an increasing challenge to medicine.