A new study finds ‘untapped biodiversity’ in the bathroom, in relation to viruses. This follows an exercise where scientists from Northwestern University collected various samples from showerheads and used toothbrushes.
This revealed more than 600 viruses, and every sample was different. It was also of interest that most of the viruses were little known or completely unknown. The viruses were not of a risk to humans and the vast majority are viruses that infect bacteria – the bacteriophages.
Although ‘phages have been studies for decades, researchers continue to know little about them overall. Given that ‘phages have recently come back in scientific popularity in terms of their potential use in treating antibiotic-resistant bacterial infections, the variety of new species provides research material for exploring antibacterial strategies further.
“The number of viruses that we found is absolutely wild,” Northwestern’s Erica M. Hartmann, explains “We found many viruses that we know very little about and many others that we have never seen before. It’s amazing how much untapped biodiversity is all around us. And you don’t even have to go far to find it; it’s right under our noses.”
“This project started as a curiosity,” Hartmann adds. “We wanted to know what microbes are living in our homes. If you think about indoor environments, surfaces like tables and walls are really difficult for microbes to live on. Microbes prefer environments with water. And where is there water? Inside our showerheads and on our toothbrushes.”
For part of the research, Hartmann’s team launched the Toothbrush Microbiome Project, which asked people to mail in their used toothbrushes along with corresponding metadata. Hartmann’s team then extracted DNA from the bristles to examine the microbial communities found there.
Hartmann used DNA sequencing to examine the viruses living on those same samples. DNA sequencing refers to the general laboratory technique for determining the exact sequence of nucleotides, or bases, in a DNA molecule.
In terms of the sequencing outcomes, Hartmann summarises: “We saw basically no overlap in virus types between showerheads and toothbrushes. We also saw very little overlap between any two samples at all. Each showerhead and each toothbrush is like its own little island. It just underscores the incredible diversity of viruses out there.”
Hartmann and her team did notice more mycobacteriophage than other types of phage. Mycobacteriophage infect mycobacteria, a pathogenic species that causes diseases like leprosy, tuberculosis and chronic lung infections.
All mycobacteriophages found thus far have had double-stranded DNA genomes and have been classified by their structure and appearance into siphoviridae or myoviridae
The research has been published in the journal Frontiers in Microbiomes. It is titled “Phage communities in household-related biofilms correlate with bacterial hosts but do not associate with other environmental factors.”
