title: The response of Cryptosporidium parvum to UV light.
abstract: Ultraviolet (UV) light is being considered as a disinfectant by the water industry because it appears to be very effective for controlling potential waterborne pathogens, including Cryptosporidium parvum. However, many organisms have mechanisms such as nucleotide excision repair and photolyase enzymes for repairing UV-induced DNA damage and regaining preirradiation levels of infectivity or population density. Genes encoding UV repair proteins exist in C. parvum, so the parasite should be able to regain infectivity following exposure to UV. Nevertheless, there is an increasing body of evidence that the organism is unable to reactivate following UV irradiation. This paper describes the effective inactivation of C. parvum by UV light, identifies nucleotide excision repair genes in the C. parvum and Cryptosporidium hominis genomes and discusses the inability of UV-exposed oocysts to regain infectivity.
authors.affiliation: Metropolitan Water District of Southern California, Water Quality Laboratory, 700 Moreno Avenue, La Verne, CA 91750, USA. prochelle@mwdh2o.com <prochelle@mwdh2o.com>
authors.forename: Paul A
authors.initials: PA
authors.lastname: Rochelle
authors.forename: Steve J
authors.initials: SJ
authors.lastname: Upton
authors.forename: Beth A
authors.initials: BA
authors.lastname: Montelone
authors.forename: Keith
authors.initials: K
authors.lastname: Woods
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003457:Cryptosporidiosis / Q000517:prevention & control*; D016785:Cryptosporidium parvum / Q000502:physiology / Q000528:radiation effects*; D004249:DNA Damage / Q000502:physiology; D004260:DNA Repair / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D011740:Pyrimidine Dimers; D016415:Sequence Alignment; D014466:Ultraviolet Rays; D014867:Water / Q000469:parasitology; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D011740:Pyrimidine Dimers; D014867:Water