Mafie, Eliakunda2026-03-302026-03-302019https://www.suaire.sua.ac.tz/handle/20.500.14820/7469PhD ThesesTaxonomy of the genus Trypanosoma Gruby, 1843 (Kinetoplastea: Trypanosomatida: Trypanosomatidae), is at challenging yet, particularly that for trypanosomes classified in the section Stercoraria. Representative are so-called rodent trypanosomes of the subgenus Herpetosoma, i.e. Trypanosoma lewisi (Kent, 1880) and its relatives, and trypanosomes of the subgenus Schizotrypanum, such as Trypanosoma crnzi Chagas, 1909 and its relatives. For a long time, morphological differentiation of stercorarian trypanosomes depended considerably upon our assumption of their rigid host-specificity, but molecular approaches introduced widely in the taxonomical study in the last two decades have demonstrated that this taxonomy is subjective enough. In the present study, I have approached taxonomically trypanosomes in small mammals such as rodents, soricids and bats, clarifying localization of taxonomic problems related to them. In Chapter I, I outlined briefly records of atypical human trypanosomiasis caused by T. lewisi and T. evansi as an opportunistic infection, and updated the current status of molecular approaches to T. lewisi or T. lewisi-WYs trypanosomes in rodents based mainly on the ribosomal RNA gene (rDNA) and glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) gene. A limited number of deposited nucleotide sequences of nominal rodent trypanosome species, eight out of ca. 50 species, at the databases made reliable diagnosis and specific taxonomy of T. lewisi-WYs trypanosomes difficult. In addition, some nominal species such as T. lewisi, T. musculi and T. blanchardi have an almost identical rDNA sequences with few nucleotide substitutions, while T. grosi showes substantial intraspecific genetic variations even more than interspecific genetic variations of the aforementioned Herpetosoma trypanosomes. In Chapter II, I collected blood samples of 89 murid rodents of 15 species and 11 soricids of four species in Indonesia, Philippines, Vietnam, Taiwan, and mainland China with help of colleagues, and characterized trypanosomes based on morphology and nucleotide sequences of the rDNA and gGAPDH gene. T. lewisi and T. lewisi-V\k& trypanosomes were found in the blood smears of 10 murids, which included Bandicota indica (two rats), Rattus argentiventer (one rat), and Rattus tiomanicus (two rats) in Indonesia; Rattus rattus (one rat) in the Philippines; and Niviventer confucianus (four rats) in mainland China. Furthermore, large- or medium-sized non-T. /ewzsz-like trypanosomes were detected in two soricids, Crocidura dracula in Vietnam and Anourosorexyamashinai in Taiwan, respectively. At last, 1 erected three new species, i.e. T. niviventerae n. sp., T. sapaensis n. sp., and T. anourosoricis n. sp. for isolates from N. confucianus in mainland China, C. dracula in Vietnam and .4. yamashinai in Taiwan, respectively. In chapter III, I characterized trypanosomes in the blood samples of bats (Miniopterus fu/iginosus') from Japan, and reported for the first time the distribution of T. dionisii Bettencourt et Franpa, 1905 of the T. cruzi clade in Asia. Our genetic characterization of the Asian isolate had biogeographical significance in discussion of the speciation and dispersion of bat-infecting trypanosomes and zoonotic T. cruzi endemic in the Latin America. We are still a long way from understanding the real biodiversity of trypanosomes in the Stercoraria section. I believe, however, our effort to collect and characterise more isolates not only by morphology but also genetically of trypanosomes in small mammals such as rodents, soricids and bats may unveil their real ‘species’ in science.enTrypanosomeMammalsSmall-ParasitesBats-ParasitesRodents-ParasitesShrews-ParasitesThesis