Department of Biology, Faculty of Science, Mahasarakham University, Kantharawichai District, Maha Sarakham 44150, Thailand.
Trop Biomed. 2023 Jun 1;40(2):188-193. doi: 10.47665/tb.40.2.010.
Culicoides Latreille biting midges are important blood feeding insects. Many species are pests and vectors of the disease causing agents including viruses, protozoa and filarial nematodes which can be transmitted to humans and other animals. However, knowledge of the role of Culicoides as vectors of filarial nematodes is limited, particular in Thailand, where at least 100 species of the genus Culicoides have been reported. In this study, a molecular approach using the 12S rRNA gene sequence was used to detecting the filarial nematode in four common biting midge species, C. actoni Smith, C. oxystoma Kieffer, C. peregrinus Kieffer and C. mahasarakhamense Pramual, Jomkumsing, Piraonapicha & Jumpato in animal shelters from northeastern Thailand. A total of 1,721 specimens were used for molecular screening. An unidentified Onchocercidae sp. was detected in a specimen of C. mahasarakhamense collected from Maha Sarakham province. This filarial species shows 93% sequence similarity with an unidentified Onchocercidae sp. isolated from Culex mosquitoes. Phylogenetic analyses revealed that Onchocercidae sp. from C. mahasarakhamense formed a clade with strong bootstrap support (100%) with filarial species detected in birds. Thus, it is very likely that the Onchocercidae sp. found in this study employes birds as vertebrate hosts which agrees with feeding behavior of C. mahasarakhamense which is known to feed on chicken. Further study is requiring to examine whether this biting midge species is a competent vector of this Onchocercidae sp.
致纹皮蝇蛆的媒介。许多物种都是害虫和疾病病原体的载体，包括病毒、原生动物和丝虫，这些病原体可以传播给人类和其他动物。然而，关于致纹皮蝇蛆作为丝虫媒介的作用知之甚少，特别是在泰国，那里已经报道了至少 100 种致纹皮蝇蛆。在这项研究中，使用 12S rRNA 基因序列的分子方法检测了来自泰国东北部动物收容所的四种常见吸血蠓，即 Actoni 蠓、Oxystoma 蠓、Peregrinus 蠓和 Mahasarakhamense 蠓。共使用了 1721 个标本进行分子筛选。从马哈萨拉卡姆省采集的 Mahasarakhamense 标本中检测到一种未鉴定的 Onchocercidae sp。这种丝虫与从库蚊中分离到的一种未鉴定的 Onchocercidae sp. 具有 93%的序列相似性。系统发育分析表明，来自 Mahasarakhamense 的 Onchocercidae sp. 与在鸟类中检测到的丝状物种形成了一个具有强烈自举支持（100%）的分支。因此，很可能本研究中发现的 Onchocercidae sp. 利用鸟类作为脊椎动物宿主，这与已知以鸡为食的 Mahasarakhamense 的摄食行为相吻合。需要进一步研究来检查这种吸血蠓是否是这种 Onchocercidae sp. 的有效媒介。
