Everyone wonders what bugs might be lurking in public bathrooms. Now researchers are using novel genetic sequencing methods to answer this question, revealing a plethora of bacteria all around, from the doors and the floors to the faucet handles and toilet seats, with potential public health implications, as reported in the online journal PLoS ONE.

Led by Gilberto Flores and Noah Fierer of the University of Colorado, Boulder, the researchers investigated 12 public restrooms, 6 male and 6 female, in Colorado.

Using a high-throughput genetic sequencing technique, they identified various bacteria on all the surfaces they tested.

The floor had the most diverse bacterial community, and human skin was the primary source of bacteria on all surfaces. Interestingly, there were a few differences between the bacteria found in the male versus female bathrooms.

The sequencing approach they used also allowed them to determine the source of the bacteria they identified, including skin, soil, and urine.

This methodology, according to the authors, could potentially help "analyze bathroom bacterial communities to identify proper (or improper) hygiene habitats, and that the exchange of bacteria on building surfaces may represent an important mode of pathogen transmission between individuals."

Flores GE, Bates ST, Knights D, Lauber CL, Stombaugh J, et al. (2011) Microbial Biogeography of Public Restroom Surfaces. PLoS ONE 6(11): e28132.doi:10.1371/journal.pone.0028132