title: Infectivity of preserved Cryptosporidium parvum oocysts for immunosuppressed adult mice.
abstract: The present study was undertaken to determine the infectivity of Cryptosporidium parvum oocysts for immunosuppressed adult C57BL/6N mice after the oocysts had been stored from 1-48 months at 4 degrees C in 2.5% potassium dichromate. All mice inoculated with oocysts 1-18 months old developed patent infections, while mice inoculated with older oocysts remained uninfected. The prepatent period was extended from 2 to 6 or 7 days as the storage time for oocysts increased. The finding that C. parvum oocysts remain infective for mice for at least 18 months offers important economic and time-saving advantages for investigators who frequently require large numbers of oocysts that must be painstakingly purified from calf manure.
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan 84322-5600, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yang
authors.forename: M C
authors.initials: MC
authors.lastname: Healey
authors.forename: C
authors.initials: C
authors.lastname: Du
mesh_terms: D000818:Animals; D003457:Cryptosporidiosis / Q000469:parasitology* / Q000473:pathology; D016785:Cryptosporidium parvum / Q000254:growth & development* / Q000472:pathogenicity*; D003907:Dexamethasone / Q000494:pharmacology; D005243:Feces / Q000469:parasitology; D005260:Female; D007082:Ileum / Q000469:parasitology; D016867:Immunocompromised Host; D051379:Mice; D008810:Mice, Inbred C57BL; D011309:Preservation, Biological
chemical_list: D003907:Dexamethasone