title: Inactivation of Ichthyophonus spores using sodium hypochlorite and polyvinyl pyrrolidone iodine.
abstract: Chlorine and iodine solutions were effective at inactivating Ichthyophonus spores in vitro. Inactivation in sea water increased directly with halogen concentration and exposure duration, with significant differences (P < 0.05) from controls occurring at all chlorine concentrations and exposure durations tested (1.5-13.3 ppm for 1-60 min) and at most iodine concentrations and exposure durations tested (1.2 ppm for 60 min and 5.9-10.7 ppm for 1-60 min). However, 10-fold reductions in spore viability occurred only after exposure to halogen solutions at higher concentrations and/or longer durations (13 ppm total chlorine for 1-60 min, 5.9 ppm total iodine for 60 min, and 10.7 ppm total iodine for 1-60 min). Inactivation efficacy was greater when halogen solutions were prepared in fresh water, presumably because of combined effects of halogen-induced inactivation and general spore instability in fresh water. The results have practical implications for disinfection and biocontainment in research laboratories and other facilities that handle live Ichthyophonus cultures and/or infected fish.
authors.affiliation: Marrowstone Marine Field Station, Western Fisheries Research Center, United States Geological Survey, Nordland, WA 98358, USA. phershberger@usgs.gov
authors.forename: P K
authors.initials: PK
authors.lastname: Hershberger
authors.forename: C A
authors.initials: CA
authors.lastname: Pacheco
authors.forename: J L
authors.initials: JL
authors.lastname: Gregg
mesh_terms: D000818:Animals; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection; D004305:Dose-Response Relationship, Drug; D050298:Mesomycetozoea / Q000187:drug effects*; D011206:Povidone-Iodine / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000494:pharmacology*; D013170:Spores / Q000187:drug effects*; D014867:Water / Q000469:parasitology
chemical_list: D004202:Disinfectants; D014867:Water; D011206:Povidone-Iodine; D012973:Sodium Hypochlorite