Susceptibility of five strains of oocysts to UV light.

Previous evaluations of the effect of ultraviolet (UV) light on oocysts have been limited to a single strain-the Iowa strain. This study investigated the response of five strains of to UV. A collimated beam apparatus was used to apply controlled doses of monochromatic (254 nm) UV to oocysts of the Iowa, Moredun, Texas A&M, Maine, and Glasgow strains.

Comparison of in vitro cell culture and a mouse assay for measuring infectivity of Cryptosporidium parvum.

In vitro cell cultures were compared to neonatal mice for measuring the infectivity of five genotype 2 isolates of Cryptosporidium parvum. Oocyst doses were enumerated by flow cytometry and delivered to animals and cell monolayers by using standardized procedures. Each dose of oocysts was inoculated into up to nine replicates of 9 to 12 mice or 6 to 10 cell culture wells.