title: Effects of high temperature and disinfectants on the viability of Sarcocystis neurona sporocysts.
abstract: The effect of moist heat and several disinfectants on Sarcocystis neurona sporocysts was investigated. Sporocysts (4 million) were suspended in water and heated to 50, 55, 60, 65, and 70 C for various times and were then bioassayed in interferon gamma gene knockout (KO) mice. Sporocysts heated to 50 C for 60 min and 55 C for 5 min were infective to KO mice, whereas sporocysts heated to 55 C for 15 min and 60 C or more for 1 min were rendered noninfective to mice. Treatment with bleach (10, 20, and 100%), 2% chlorhexidine, 1% betadine, 5% o-benzyl-p-chlorophenol, 12.56% phenol, 6% benzyl ammonium chloride, and 10% formalin was not effective in killing sporocysts. Treatment with undiluted ammonium hydroxide (29.5% ammonia) for 1 hr killed sporocysts, but treatment with a 10-fold dilution (2.95% ammonia) for 6 hr did not kill sporocysts. These data indicate that heat treatment is the most effective means of killing S. neurona sporocysts in the horse feed or in the environment.
authors.affiliation: Parasite Biology, Epidemiology and Systematics Laboratory, Building 1001, Animal and Natural Resources Institute, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705-2350, USA. jdubey@anri.barc.usda.gov
authors.forename: J P
authors.initials: JP
authors.lastname: Dubey
authors.forename: W J
authors.initials: WJ
authors.lastname: Saville
authors.forename: C
authors.initials: C
authors.lastname: Sreekumar
authors.forename: S K
authors.initials: SK
authors.lastname: Shen
authors.forename: O S
authors.initials: OS
authors.lastname: Lindsay
authors.forename: H F
authors.initials: HF
authors.lastname: Pena
authors.forename: M C
authors.initials: MC
authors.lastname: Vianna
authors.forename: S M
authors.initials: SM
authors.lastname: Gennari
authors.forename: S M
authors.initials: SM
authors.lastname: Reed
mesh_terms: D000821:Animal Feed / Q000469:parasitology; D000818:Animals; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D005506:Food Contamination / Q000517:prevention & control; D006734:Horse Diseases / Q000517:prevention & control; D006736:Horses; D006358:Hot Temperature; D051379:Mice; D018345:Mice, Knockout; D009893:Opossums; D011821:Raccoons; D012522:Sarcocystis / Q000187:drug effects / Q000502:physiology*; D012523:Sarcocystosis / Q000517:prevention & control / Q000662:veterinary
chemical_list: D004202:Disinfectants