Shower Curtains May Harbor Harmful Microbes

Filmy residue, or “soap scum”, on household shower curtains may be a breeding ground for potentially harmful bacteria say researchers from San Diego State University, California, University of Colorado at Boulder, and Washington University in St. Louis, Missouri.  Their findings appear in the July 2004 issue of the journal Applied and Environmental Microbiology.


“One household environment that potentially accumulates microbial biofilms is that provided by vinyl shower curtains.  Over time, vinyl shower curtains accumulate films, commonly referred to as “soap scum,” which microscopy reveals are constituted of lush microbial biofilms,” say the researchers.


In the study DNA samples were taken from four vinyl shower curtains in different homes.  A broad range of RNA gene sequences were revealed with Sphingomonas spp. and Methylobacterium spp. appearing as the most prominent, both of which are considered to be opportunistic pathogens commonly associated with water reservoirs.


“These results show that shower curtains are a potential source of opportunistic pathogens associated with biofilms,” say the researchers.  “Frequent cleaning or disposal of shower curtains is indicated, particularly in households with immune-compromised individuals.”


(S.T. Kelley, U. Theisen, L.T. Angenent, A. St. Amand, N.R. Pace.  2004.  Molecular analysis of shower curtain biofilm microbes.  Applied and Environmental Microbiology, 70. 7: 4187-4192.)