This study aimed to evaluate and document the excystation process of Cryptosporidium muris oocysts in various incubation media, and to monitor the behaviour of excysting and freshly excysted sporozoites. A test of oocyst viability, using fluorescent double staining with fluorescein diacetate and propidium iodide, was performed prior to each experimental assay. Light microscope observations confirmed that relatively often only three sporozoites were released; the fourth one either left the oocyst later together with a residual body or remained trapped within the oocyst wall. These results suggest that successful oocyst excystation is not limited by the viability of all four sporozoites. Darkening of oocysts to opaque and their specific movement (the so-called "oocyst dancing") preceded the final excystation and liberation of sporozoites, while the dormant oocysts appeared refractive. The process of excystation in C. muris is not gradual as generally described in cryptosporidia but very rapid in an eruptive manner. Experiments were performed using oocysts stored at 4 °C for various time periods, as well as oocysts freshly shed from host rodents (Mastomys coucha) of different ages. The most suitable medium supporting high excystation rate (76 %) and prolonged motility of sporozoites was RPMI 1640, enriched with 5 % bovine serum albumin (BSA). Our results emphasize that to reliably evaluate the success of in vitro excystation of cryptosporidia, not only the number of released sporozoites in a set time period should be taken into consideration but also their subsequent activity (motility), as it is expected to be essential for the invasion of host cells.

Department of Botany and Zoology Faculty of Science Masaryk University Kotlářská 2 611 37 Brno Czech Republic

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J Eukaryot Microbiol. 2007 Nov-Dec;54(6):495-510 PubMed

Parasitology. 2004 Mar;128(Pt 3):269-82 PubMed

Parasitol Res. 2011 Dec;109(6):1719-23 PubMed

J Parasitol. 1996 Dec;82(6):889-92 PubMed

FEMS Microbiol Lett. 2000 Feb 15;183(2):331-6 PubMed

J Parasitol. 2001 Jun;87(3):575-81 PubMed

Int J Parasitol. 2008 Jul;38(8-9):913-22 PubMed

Int J Parasitol. 2011 Mar;41(3-4):287-92 PubMed

J Parasitol. 2001 Oct;87(5):997-1000 PubMed

J Clin Microbiol. 2011 Jan;49(1):34-41 PubMed

J Parasitol. 1987 Apr;73(2):314-9 PubMed

J Parasitol. 2010 Feb;96(1):211-2 PubMed

Clin Microbiol Rev. 2002 Jul;15(3):390-400 PubMed

Parasitology. 1989 Dec;99 Pt 3:329-31 PubMed

Appl Environ Microbiol. 1992 Nov;58(11):3494-500 PubMed

Parasitology. 2007 Oct;134(Pt 11):1583-8 PubMed

Trends Parasitol. 2005 Mar;21(3):133-42 PubMed

FEMS Microbiol Lett. 2007 Mar;268(2):202-8 PubMed

Emerg Infect Dis. 2002 Feb;8(2):204-6 PubMed

J Appl Microbiol. 2008 Apr;104(4):980-6 PubMed

Parasitol Res. 2003 Jan;89(1):1-5 PubMed

Trends Parasitol. 2006 Oct;22(10):463-8 PubMed

Vet Parasitol. 2011 Jan 10;175(1-2):160-4 PubMed

J Protozool. 1986 Feb;33(1):98-108 PubMed

J Protozool. 1985 Nov;32(4):708-11 PubMed

Curr Trends Biotechnol Pharm. 2008 Mar;2(2):66-84 PubMed

J Histochem Cytochem. 1985 Jan;33(1):77-9 PubMed

Parasitol Res. 1999 Nov;85(11):899-904 PubMed

Vet Parasitol. 2007 Mar 31;144(3-4):349-52 PubMed

Am J Trop Med Hyg. 1987 May;36(3):505-8 PubMed

Parasitology. 1993 Jan;106 ( Pt 1):13-9 PubMed

J Exp Zool. 1982 Jul 20;222(1):81-8 PubMed

J Protozool. 1984 Nov;31(4):567-9 PubMed

J Parasitol. 1998 Dec;84(6):1165-9 PubMed

J Infect Dis. 1999 Oct;180(4):1275-81 PubMed

Appl Environ Microbiol. 1998 Mar;64(3):1070-4 PubMed

J Parasitol. 2012 Oct;98(5):946-50 PubMed

Emerg Infect Dis. 2003 Sep;9(9):1174-6 PubMed

Vet Parasitol. 2008 May 31;153(3-4):363-7 PubMed