title: Statistical comparison of excystation methods in Cryptosporidium parvum oocysts.
abstract: Excystation of sporozoites of Cryptosporidium parvum from oocysts is essential for successful in vitro assays. It has also been traditionally used as a measure for oocyst viability and infectivity. Laboratories use various excystation protocols so there is a need to clarify which method is the best. In this study, six different protocols for in vitro excystation of C. parvum oocysts were compared to find the most efficient excystation method (expressed as percentage excystation). Tested protocols differed in chemical pre-incubation steps, excystation media or time of incubation. There were significant differences in percentage of excysted oocysts among groups excysted by different methods. There were also significant differences in percentage of excysted oocysts between methods using pre-incubation with sodium hypochlorite and those without. The other variables examined; the presence of trypsin, kind of excystation medium and the incubation time, did not show statistical differences in percentage excystation among groups. Pre-incubation steps which included sodium hypochlorite, enhancing the permeability of the oocysts were found to increase the excystation ratio and methods using this step were the most effective.
authors.affiliation: Department of Botany and Zoology, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic. Electronic address: ra.pe@seznam.cz.
authors.forename: Radka
authors.initials: R
authors.lastname: Pecková
authors.affiliation: Department of Botany and Zoology, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic. Electronic address: peterdstuart@hotmail.com.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Stuart
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences of the Czech Republic, v.v.i., Branišovská 31, 37005, České Budějovice, Czech Republic. Electronic address: casio@paru.cas.cz.
authors.forename: Bohumil
authors.initials: B
authors.lastname: Sak
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences of the Czech Republic, v.v.i., Branišovská 31, 37005, České Budějovice, Czech Republic. Electronic address: dana@paru.cas.cz.
authors.forename: Dana
authors.initials: D
authors.lastname: Květoňová
authors.affiliation: Institute of Parasitology, Biology Centre of the Czech Academy of Sciences of the Czech Republic, v.v.i., Branišovská 31, 37005, České Budějovice, Czech Republic. Electronic address: kvac@paru.cas.cz.
authors.forename: Martin
authors.initials: M
authors.lastname: Kváč
authors.affiliation: Department of Botany and Zoology, Masaryk University, Kotlářská 2, 611 37, Brno, Czech Republic. Electronic address: ivona_foi@hotmail.com.
authors.forename: Ivona
authors.initials: I
authors.lastname: Foitová
mesh_terms: D000818:Animals; D016785:Cryptosporidium parvum / Q000187:drug effects / Q000502:physiology*; D003470:Culture Media / Q000494:pharmacology; D033661:Oocysts / Q000187:drug effects; D010274:Parasitology / Q000379:methods*; D010539:Permeability / Q000187:drug effects; D012973:Sodium Hypochlorite / Q000494:pharmacology; D014357:Trypsin / Q000494:pharmacology
chemical_list: D003470:Culture Media; D012973:Sodium Hypochlorite; D014357:Trypsin
keywords: Cryptosporidium parvum; Excystation methods; In vitro cultivation; Sodium hypochlorite; Trypsin