title: Life without a Host Cell: What is Cryptosporidium?
abstract: Cryptosporidium is a parasite responsible for widespread disease in livestock and humans. Recent phylogenetic reclassification of Cryptosporidium from a coccidian to a gregarine dictates an urgent need to reconsider the biology and behavior of this parasite. Overwhelming data now confirm that, like its close relatives, Cryptosporidium is a facultatively epicellular apicomplexan that is able to multiply in a host cell-free environment. We complement the latest phylogenetic and taxonomic proposals with advances in our understanding of Cryptosporidium's biology, with particular focus on in vitro studies that have characterized the development of Cryptosporidium stages in the absence of host cells. Opportunities to revisit in vivo infections are discussed and questions about the Cryptosporidium host cell-free life cycle that remain unanswered highlighted.
authors.affiliation: Centre for Microscopy, Characterisation, and Analysis, The University of Western Australia, Crawley WA 6009, Australia. Electronic address: peta.clode@uwa.edu.au.
authors.forename: Peta L
authors.initials: PL
authors.lastname: Clode
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch WA 6150, Australia.
authors.forename: Wan H
authors.initials: WH
authors.lastname: Koh
authors.affiliation: School of Veterinary and Life Sciences, Murdoch University, South Street, Murdoch WA 6150, Australia.
authors.forename: R C Andrew
authors.initials: RCA
authors.lastname: Thompson
mesh_terms: D003457:Cryptosporidiosis / Q000469:parasitology / Q000503:physiopathology; D003458:Cryptosporidium / Q000145:classification / Q000502:physiology*; D004777:Environment; D006790:Host-Parasite Interactions; D008018:Life Cycle Stages