Chaorattanakawee Suwanna, Korkusol Achareeya, Tippayachai Bousaraporn, Promsathaporn Sommai, Poole-Smith Betty K, Takhampunya Ratree
Department of Entomology, US Army Medical Directorate of the Armed Forces Research Institute of Medical Sciences (USAMD-AFRIMS), Bangkok 10400, Thailand.
Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, Ratchawithi Road, Bangkok 10400, Thailand.
Pathogens. 2021 Feb 16;10(2):215. doi: 10.3390/pathogens10020215.
Next generation sequencing (NGS) technology has been used for a wide range of epidemiological and surveillance studies. Here, we used amplicon-based NGS to species identify and their arthropod hosts from entomological surveillance.
During 2015-2016, we screened 1825 samples of rodents and ectoparasites collected from rodents and domestic mammals (dog, cat, and cattle) across Thailand for . The citrate synthase gene was amplified to identify to species, while the Cytochrome Oxidase subunit I (I) and subunit II (II) genes were used as target genes for ectoparasite identification. All target gene amplicons were pooled for library preparation and sequenced with Illumina MiSeq platform.
The highest percentage of DNA was observed in fleas collected from domestic animals (56%) predominantly dogs. Only a few samples of ticks from domestic animals, rodent fleas, and rodent tissue were positive for DNA. NGS based characterization of by host identified as the most common bacteria in positive fleas collected from dogs (83.2%) while " Rickettsia senegalensis" was detected in only 16.8% of positive dog fleas. Sequence analysis of I and II revealed that almost all fleas collected from dogs were . Other species were detected by NGS including from two ticks, and in two rodent tissue samples.
This study demonstrates the utility of NGS for high-throughput sequencing in the species characterization/identification of bacteria and ectoparasite for entomological surveillance of rickettsiae. A high percentage of are positive for . In addition, our findings indicate there is a risk of tick-borne Spotted Fever Group rickettsiosis, and flea-borne murine typhus transmission in Tak and Phangnga provinces of Thailand.
下一代测序（NGS）技术已被广泛应用于各种流行病学和监测研究。在此，我们使用基于扩增子的NGS技术对昆虫监测中的物种及其节肢动物宿主进行鉴定。
在2015 - 2016年期间，我们对从泰国各地的啮齿动物以及家养哺乳动物（狗、猫和牛）采集的1825份啮齿动物和体外寄生虫样本进行了筛查。扩增柠檬酸合酶基因以鉴定物种，而细胞色素氧化酶亚基I（COI）和亚基II（COII）基因用作体外寄生虫鉴定的靶基因。将所有靶基因扩增子混合用于文库制备，并使用Illumina MiSeq平台进行测序。
在家养动物（主要是狗）身上采集的跳蚤中观察到立克次体DNA的百分比最高（56%）。仅在家养动物的蜱、啮齿动物跳蚤和啮齿动物组织的少数样本中检测到立克次体DNA呈阳性。基于NGS的宿主对立克次体的特征分析表明，从狗身上采集的阳性跳蚤中，立氏立克次体是最常见的细菌（83.2%），而在仅16.8%的立克次体阳性狗跳蚤中检测到“塞内加尔立克次体”。对COI和COII的序列分析表明，从狗身上采集的几乎所有跳蚤都是立氏立克次体。通过NGS检测到的其他立克次体物种包括来自两只革蜱的西伯利亚立克次体，以及在两个啮齿动物组织样本中的小蛛立克次体。
本研究证明了NGS在立克次体昆虫监测中细菌和体外寄生虫物种特征/鉴定的高通量测序中的实用性。高比例的立克次体呈阳性。此外，我们的研究结果表明，泰国Tak和攀牙省存在蜱传斑点热群立克次体病以及蚤传鼠型斑疹伤寒传播的风险。
