title: Establishment of the complete life cycle of Spirometra (Cestoda: Diphyllobothriidae) in the laboratory using a newly isolated triploid clone.
abstract: Methods to maintain the life cycle of pathogenic organisms become powerful tools for studying molecular and cellular bases of infectious diseases. Spirometra erinaceieuropaei is a parasitic tapeworm that causes sparganosis in humans. Because S. erinaceieuropaei has a complex life cycle with different stages and host species requirements, there have been no reports to establish the complete life cycle in the laboratory. In this study, using Cyclops as the first intermediate host, mouse as the experimental second intermediate host, and dog as the final host, we succeeded in maintaining S. erinaceieuropaei in the laboratory. By repeating the established life cycle five times, we obtained a clonal population of S. erinaceieuropaei from a single adult worm. A karyotype study showed that the chromosome of this clone is triploid (3n=27), indicating that a genetically uniform strain is established by apomictic reproduction. The strain was named Kawasaki triploid (Kt). A partial sequence of mitochondrial cytochrome c oxidase subunit 1 gene of the strain Kt showed more than 98% similarity with those of S. erinaceieuropaei isolates from Australia, China, and South Korea, and the resultant phylogeny indicated that the strain Kt is a member of a distinctive clade from East Asia and Oceania. Our system will be particularly useful for studies of S. erinaceieuropaei infection and human sparganosis.
authors.affiliation: Department of Microbiology, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192, Japan. Electronic address: okino@med.kawasaki-m.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Okino
authors.affiliation: Department of Microbiology, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ushirogawa
authors.affiliation: Department of Microbiology, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Matoba
authors.affiliation: Department of Molecular Biology, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192, Japan.
authors.forename: Shin-Ichiro
authors.initials: SI
authors.lastname: Nishimatsu
authors.affiliation: Department of Microbiology, Kawasaki Medical School, 577 Matsushima, Kurashiki 701-0192, Japan. Electronic address: mineki@med.kawasaki-m.ac.jp.
authors.forename: Mineki
authors.initials: M
authors.lastname: Saito
mesh_terms: D000818:Animals; D001315:Australia; D002590:Cestode Infections / Q000469:parasitology; D002681:China; D004272:DNA, Mitochondrial; D004285:Dogs; D005202:Asia, Eastern; D050259:Genes, Mitochondrial; D014644:Genetic Variation; D006790:Host-Parasite Interactions; D006801:Humans; D059785:Karyotype; D008018:Life Cycle Stages; D051379:Mice; D010802:Phylogeny; D056910:Republic of Korea; D013031:Sparganosis / Q000469:parasitology; D013146:Spirometra / Q000235:genetics* / Q000254:growth & development*; D057885:Triploidy
chemical_list: D004272:DNA, Mitochondrial
keywords: Complete life cycle; New model organism; Sparganosis; Spirometra erinaceieuropaei; Triploid