| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2004: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Research Abstract |
Ever since the first description of Blastocystis hominis found in human intestinal tract in 1912, this parasite has been widely isolated from a variety animals including non-human primates, mammals, birds, reptiles, amphibians and insects. Blastocystis isolates from mammals and birds are known to be classified into 7 kinds of different clades inferred from the small subunit rRNA genes. Since most of the clades shared between humans and animals, most human Blastocystis isolates have been assumed to be zoonotic. Most attempts undertaken to date to assess the zoonotic potential of human Blastocystis isolates in host animals have not been completely successful. This study demonstrated that rats are susceptible animals to both RN94-9 and NIH:1295-1 isolates recovered from a laboratory rat and a guinea pig, respectively. Moreover, chicks were susceptible to all of 6 Blastocystis isolates from chickens, quails and geese. Therefore, rats and chicks are useful animal model for Blastocystis infection. In addition, transmission of this parasite caused by ingestion of fecal cysts was also demonstrated in this study. Infectivity associated with several unique human Blastocystis genotypes was also investigated by infecting chicks and rats with two isolates of each genotype experimentally. Our results confirmed that several genotypes of human isolates could infect chicks and/or rats, indicating that chicks and rats are suitable experimental animals models for studying the zoonotic potential of human Blastocystis isolates.
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