Microbiologists have discovered that showerheads and toothbrushes are filled with a remarkably varied array of viruses, many of which are previously unknown.
Forget about tropical rainforests and coral reefs; the new location of astonishing biodiversity is your bathroom.
In a recent study led by Northwestern University, researchers found that both showerheads and toothbrushes host a strikingly diverse collection of viruses, most of which have never been documented.
While this may sound alarming, the reassuring aspect is that these viruses do not pose a threat to humans. Instead, they target bacteria.
The microorganisms identified in the study are known as bacteriophages, or “phages,” which are viruses that infect and reproduce within bacteria. Although there is still much to learn about them, phages are gaining attention for their potential in treating infections caused by bacteria that are resistant to antibiotics. The unknown viruses lurking in our bathrooms could serve as a valuable resource for exploring such applications.
This study will be published on Wednesday (Oct. 9) in the journal Frontiers in Microbiomes.
“The sheer number of viruses we discovered is astonishing,” remarked Erica M. Hartmann of Northwestern, who spearheaded the study. “We came across many viruses that are largely unfamiliar and numerous others that are entirely new to science. It’s incredible to realize how much unexplored biodiversity exists all around us, and we don’t have to travel far to find it; it’s right in our homes.”
Hartmann, an indoor microbiologist, serves as an associate professor of civil and environmental engineering at Northwestern’s McCormick School of Engineering and is affiliated with the Center for Synthetic Biology.
The revival of ‘Operation Pottymouth’
This new research stems from earlier studies in which Hartmann and her colleagues at the University of Colorado at Boulder analyzed the bacteria on toothbrushes and showerheads. Participants were invited to send in used toothbrushes and samples from their showerheads.
Due to concerns about aerosol particles produced by flushing toilets, Hartmann humorously dubbed the toothbrush study “Operation Pottymouth.”
“This project originated from a sense of curiosity,” Hartmann said. “We wanted to learn about the microbes inhabiting our living spaces. Indoor environments tend to be inhospitable for microbes on surfaces like tables and walls, which makes them more likely to thrive where moisture is present — namely, in our showerheads and on our toothbrushes.”
Diversity and possibilities
After investigating the bacteria, Hartmann employed DNA sequencing to analyze the viruses in the same samples and was taken aback by the results. The findings revealed more than 600 distinct viruses, with each sample being unique.
“We hardly saw any similarities in virus types between showerheads and toothbrushes,” Hartmann noted. “Moreover, there was very little overlap among any of the samples. Each showerhead and toothbrush resembles its own miniature ecosystem, highlighting the overwhelming diversity of viruses that exist.”
Despite the lack of patterns in the sample data, Hartmann and her team observed a higher presence of mycobacteriophages compared to other types of phages. Mycobacteriophages infect mycobacteria, which can cause serious diseases like leprosy, tuberculosis, and chronic lung infections. Hartmann envisions a future where researchers could utilize mycobacteriophages to combat these illnesses.
“We could consider employing these mycobacteriophages to eliminate pathogens from plumbing systems,” she proposed. “Our goal is to understand the various roles these viruses might play and explore how we can harness them.”
Most microbes ‘will not harm us’
In the meantime, Hartmann advises against worrying about the unseen microorganisms in our bathrooms. Rather than reaching for bleach, she recommends soaking showerheads in vinegar to remove calcium deposits or cleaning them with soap and water. Additionally, she suggests replacing toothbrush heads regularly and is not an advocate for antimicrobial toothbrushes, which could contribute to the development of antibiotic-resistant bacteria.
“Microbes are ubiquitous, and the vast majority will not cause illness,” she explained. “The more we use harsh disinfectants, the more likely these microbes are to evolve resistance or become harder to treat. It’s better to co-exist with them.”
The study, “Phage communities in household-related biofilms correlate with bacterial hosts but do not associate with other environmental factors,” received support from Northwestern University.
