Molecular characterization of the ribosomal DNA unit of Sarcocystissingaporensis, Sarcocystis zamani and Sarcocystiszuoi from rodents in Thailand

[摘要] Sarcocystis species are heteroxenous cyst-forming coccidian protozoanparasites with a wide host range, including rodents. In this study,Sarcocystis spp. samples were isolated from Bandicotaindica, Rattus argentiventer, R. tiomanicusand R. norvegicus across five provinces of Thailand. Two major groups ofSarcocystis cysts were determined in this study large and small cysts.By sequence comparisons and phylogenetic analyses based on the partial sequences of 28Sribosomal DNA, the large cysts showed the highest identity value (99%) with the S.zamani in GenBank database. While the small cysts could be divided into 2groups of Sarcocystis S. singaporensis and presupposedS. zuoi. The further analysis on 18S rDNA supported that the 2 isolates(S2 and B6 no.2) were as identified as S. singaporensis shared a highsequence identity with the S. singaporensis in GenBank database and theunidentified Sarcocystis (4 isolates, i.e., B6 no.10, B6 no.12, B10 no.4and B10 no.7) showed 96.3–99.5% identity to S. zuoi as well as highdistinct identity from others Sarcocystis spp. (≤93%). The resultindicated that these four samples should be S. zuoi. In this study, weprovided complete sequence of internal transcribed spacer 1 (ITS1), 5.8S rDNA and internaltranscribed spacer 2 (ITS2) of these three Sarcocystis species and ournew primer set could be useful to study the evolution of Sarcocystis.

[学科分类] 兽医学

[关键词] phylogenetic analysis;rodent intermediate hosts;Sarcocystis spp.