Department of Biology, Faculty of Science, Mahasarakham University, Kantharawichai District, Maha Sarakham 44150, Thailand.
Department of Entomology and Plant Pathology, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002 Thailand.
Acta Trop. 2019 Dec;200:105196. doi: 10.1016/j.actatropica.2019.105196. Epub 2019 Sep 20.
Trypanosomes are parasitic flagellate protozoans that are important disease causing agents in humans and animals including economically significant livestock. Many blood-sucking insects are known to be vectors of trypanosomes but there is no data for the haematophagous black fly species in Asia. In this study, a molecular approach based on the small subunit ribosomal RNA (SSU rRNA) gene was used to detect trypanosomes in black flies from Thailand. A total of 470 wild-caught adult black flies representing nine morphological species were examined. Ten (2%) specimens of two ornithophilic black fly species, Simulium asakoae complex (n = 4) and S. chumpornense (n = 6), were positive for trypanosomes. The SSU rRNA sequences revealed that all trypanosome DNA found in black flies from Thailand is closely related to Trypanosoma avium with >99% sequence similarity. This is also supported by a phylogenetic analysis in which all trypanosomes from Thai black flies were resolved in the clade of T. avium. This is the first report for trypanosomes in Asian black flies and it is suspected that these insects are potential vectors of avian Trypanosoma.
锥虫是寄生的鞭毛原生动物，是人类和动物（包括具有重要经济意义的牲畜）重要的致病因子。许多吸血昆虫已知是锥虫的媒介，但亚洲吸血性黑蝇物种没有相关数据。在这项研究中，基于小亚基核糖体 RNA（SSU rRNA）基因的分子方法用于检测来自泰国的黑蝇中的锥虫。共检查了代表 9 个形态种的 470 只野生捕获的成年黑蝇。两种嗜鸟黑蝇（Simulium asakoae 复合体（n=4）和 S. chumpornense（n=6））的 10 个（2%）标本对锥虫呈阳性。SSU rRNA 序列表明，在来自泰国的黑蝇中发现的所有锥虫 DNA 与禽锥虫（Trypanosoma avium）密切相关，具有>99%的序列相似性。这也得到了系统发育分析的支持，其中来自泰国黑蝇的所有锥虫都在禽锥虫（T. avium）的分支中得到解决。这是亚洲黑蝇中锥虫的首次报道，怀疑这些昆虫是禽锥虫的潜在媒介。
