การศึกษาความหลากหลายของยีน Cytochrome c oxidase subunit I (COI) ของริ้นฝอยทราย ในเขตพื้นที่ภาคใต้ตอนล่างของประเทศไทย

บทคัดย่อ

This research is study on sand fly, which an important vector of Leishmaniasis. The studies were included diversities of species; infection rate and types of parasites in sand fly on the field caught from ecotourism cave, Southern Thailand. The sand fly collecting was explored in 10 ecotourism caves are 1) Khamin cave, Surat Thani 2) Sangpet cave, Krabi 3) Khao Phlu cave, Chumphon 4) Khao Rup Chang cave, Songkhla 5) Rab-roe cave, Chumphon 6) Rakang Thong cave, Satun 7) Phra Khayang cave, Ranong 8) Le Khao Kop cave, Trang 9) Phung Chang cave, Phang-nga and 10) Su Mano cave, Patthalung. Light trap catch sand fly were use during June 2016 to April 2017. The results show 4,513 sand flies were collected with 2 genus and 21 species including 6 Phlebotomus (28.57%) and 15 Sergentomyia (71.43%). There have only 1 species of sand fly was unidentified. The highest population of sand fly is S. anodontis (28.21%), then P. major major (22.73%), P. kiangsuensis (17.42%), P. asperulus (8.66%), S. gammae (5.30%), S. hodgsoni (4.37%), S. silvatica (2.24%), S. barraudi (2.17%), P. stantoni (1.96%) and S. hamidi (1.57%) respectively. The recorded of important vector of Leishmaniasis, which P. argentipes and P. major major were found in every cave of this study. The 383 pools of Polymerase Chain Reaction (PCR) specific with Leishmania spp. 18s SSUrRNA (379 pb) were provided, and the positive result is 65 pools (16.97%). Species of sand fly that found PCR positive for Leishmania spp. are 14 species including P. major major, P. asperulus, P. kiangsuensis, P. stantoni, P. argentipes, S. anodontis, S. gammae, S. indica, S. hodgsoni, S. barraudi, S. sylvatica, S. punjabensis, S. hivernus and S. tambori. The 9 pools included P. kiangsuensis (1 pool) and P. asperulus (8 pools) were investigated for nucleotide sequencing, and presented in phylogenic tree. Nucleotide results comparison between Trypanosoma and Leishmania from The National Center for Biotechnology Information (NCBI) show that it’s more similar with Trypanosoma than Leishmania (L. donovani, L. infantum, L. martiniquensis and L. siamensis). Nucleotide sequence results illustrated the close relationship with Trypanosoma lewisi, which reported from previous study. This Trypanosomiasis is a parasitic disease of cattle group, and it can transfecting from animal to human (zoonosis). In Thailand Rattus norvegicus was positive reported for Trypanosomiasis in Chiangmai province. In this study, the Trypanosoma positive were found in 3 caves are Le Khao Kop cave, Trang, Rakang Thong cave, Satun, and Su Mano cave, Patthalung. The sand fly blood meal investigation by using PCR technique from 80 samples were found positive result with 18 samples from 6 species of sand fly including P. major major, P. asperulus, P. kiangsuensis, S. anodontis, S. silvatica, and S. hamidi. After analyzed nucleotide sequence of sand fly blood meal and compared with NCBI data base, we found that all blood meal are human blood (Homo sapiens). The cave that found human blood meal are Rakang Thong cave, Satun (P. asperulus, P. kiangsuensis, S. anodontis, S. hamidi), Phra Khayang cave, Ranong (S. anodontis), Le Khao Kop cave, Trang (P. major major, P. asperulus), and Su Mano cave, Patthalung (P. asperulus, P. kiangsuensis, S. anodontis, S. silvatica) respectively. We found 2 species of sand fly (P. kiangsuensis and P. asperulus) were detected Trypanosoma lewisi and human blood together at Rakang Thong cave, Satun. These result is an important role to be a big step for understand the interaction between sand fly, Trypanosoma lewisi and human. The deeper research is required for further study.

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