Retention and Release of Cryptosporidium parvum Oocysts by Experimental Biofilms Composed of a Natural Stream Microbial Community

Cryptosporidium parvum oocysts accumulate on biofilm surfaces. The percentage of oocysts attached to biofilms remained nearly constant while oocysts were supplied to the system but decreased to a new steady-state level once oocysts were removed from the feed. More oocysts attached to summer biofilm cultures than winter biofilm cultures.