Genetic variability of Blastocystis hominis isolates in China

Parasitol Res. 2006 Oct;99(5):597-601. doi: 10.1007/s00436-006-0186-z. Epub 2006 May 11.


To determine if genetic diversity of Blastocystis hominis exists in China, 35 B. hominis isolates obtained from 19 asymptomatic infected individuals and 16 patients with gastrointestinal symptoms were genotyped by PCR using seven pairs of known sequenced-tagged site (STS) primers. Out of the 35 isolates, 29 were identified as one of the known genotypes, while five isolates showed two distinct genotypes, and one isolate was an unknown genotype as this was negative with all the STS primers. In this study, none of the isolates was classified as subtypes 4-7. Compared with the spectrum of human B. hominis subtypes obtained from five geographically different countries (Japan, Pakistan, Bangladesh, Germany, and Thailand), these results showed that subtype 1 was more a popular genotype (18/35) in China. In addition, two groups of the isolates from 19 asymptomatic infected individuals and those from 16 patients with intestinal symptoms were compared with the PCR-based subtype classification. The results suggest a possible relationship between subtype 1 and a pathogenic potential of this parasite.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blastocystis Infections / parasitology*
  • Blastocystis hominis / genetics*
  • Blastocystis hominis / isolation & purification
  • Blastocystis hominis / pathogenicity
  • China
  • DNA, Ribosomal / genetics
  • Feces / parasitology
  • Genetic Variation*
  • Genotype
  • Phenotype
  • Polymerase Chain Reaction
  • Sequence Tagged Sites


  • DNA, Ribosomal