Abstract：
Questing ticks carry various tick-borne pathogens (TBPs) that are responsible for causing tick-borne diseases (TBDs) in humans and animals around the globe, especially in the tropics and sub-tropics. Information on the distribution of ticks and TBPs in a specific geography is crucial for the formulation of mitigation measures against TBDs. Therefore, this study aimed to survey the TBPs in the questing tick population in Bangladesh. A total of 2748 questing hard ticks were collected from the pastures in Sylhet, Bandarban, Sirajganj, Dhaka, and Mymensingh districts through the flagging method. After morphological identification, the ticks were grouped into 142 pools based on their species, sexes, life stages, and collection sites. The genomic DNA extracted from tick specimens was screened for 14 pathogens, namely Babesia bigemina (AMA-1), Babesia bovis (RAP-1), Babesia naoakii (AMA-1), Babesia ovis (18S rRNA), Theileria luwenshuni (18S rRNA), Theileria annulata (Tams-1), Theileria orientalis (MPSP), Anaplasma marginale (groEL), Anaplasma phagocytophilum (16S rRNA), Anaplasma bovis (16S rRNA), Anaplasma platys (16S rRNA), Ehrlichia spp. (16S rRNA), Rickettsia spp. (gltA), and Borrelia (Bo.) spp. (flagellin B) using genus and species-specific polymerase chain reaction (PCR) assays. The prevalence of the detected pathogens was calculated using the maximum likelihood method (MLE) with 95 % confidence interval (CI). Among 2748 ixodid ticks, 2332 (84.86 %) and 416 (15.14 %) were identified as Haemaphysalis bispinosa and Rhipicephalus microplus, respectively. Haemaphysalis bispinosa was found to carry all the seven detected pathogens, while larvae of R. microplus were found to carry only Bo. theileri. Among the TBPs, the highest detection rate was observed in A. bovis (20/142 pools, 0.81 %, CI: 0.51-1.20), followed by T. orientalis (19/142 pools, 0.72 %, CI: 0.44-1.09), T. luwenshuni (9/142 pools, 0.34 %, CI: 0.16-0.62), B. ovis (4/142 pools, 0.15 %, CI: 0.05 - 0.34) and Bo. theileri (4/142 pools, 0.15 %, CI: 0.05-0.34), Ehrlichia ewingii (3/142 pools, 0.11 %, CI: 0.03-0.29), and Babesia bigemina (1/142, 0.04 %, CI: 0.00 - 0.16). This study reports the existence of T. luwenshuni, E. ewingii, and Bo. theileri in Bangladesh for the first time. The novel findings of this study are the foremost documentation of transovarian transmission of B. bigemina and E. ewingii in H. bispinosa and also provide primary molecular evidence on the presence of E. ewingii and Bo. theileri in H. bispinosa. Therefore, this study may shed light on the circulating TBPs in ticks in the natural environment and thereby advocate awareness among physicians and veterinarians to control and prevent TBDs in Bangladesh.
摘要：
探查壁虱携带各种壁虱传播的病原体（TBP），这些病原体负责在全球人类和动物中引起壁虱传播的疾病（TBD），特别是在热带和亚热带地区。有关特定地理区域中蜱和TBP分布的信息对于制定针对TBD的缓解措施至关重要。因此,这项研究旨在调查孟加拉国tick虫种群的TBP。从Sylhet的牧场中收集了总共2748个搜寻硬蜱，班达班,Sirajganj,达卡,和迈门辛格地区通过标记方法。经过形态学鉴定,根据它们的种类将蜱分成142个池，性别,生命阶段,和收集网站。从蜱标本中提取的基因组DNA筛选出14种病原体，即Babesiabigemina（AMA-1），Babesiabovis(RAP-1),naoakiiBabesia(AMA-1),卵巴贝虫（18SrRNA），Theilerialuwenshuni(18SrRNA)，环流泰勒(Tams-1)，东方TheileriaOrientalis（MPSP），边缘无性体(groEL),吞噬细胞无性体（16SrRNA），牛无性体（16SrRNA），无性分裂样（16SrRNA），埃里希菌属。（16SrRNA），立克次体属。(gltA),和疏螺旋体(Bo.)spp。（鞭毛蛋白B）使用属和物种特异性聚合酶链反应（PCR）测定。使用最大似然法（MLE）以95％置信区间（CI）计算检测到的病原体的患病率。在2748个伊克多蜱中，2332（84.86％）和416（15.14％）被鉴定为双皮松血丝和微血丝，分别。我们发现双皮科血友病携带所有检测到的七种病原体，而R.microplus的幼虫被发现只携带Bo。Theileri.在TBP中，在A.bovis中观察到最高的检出率（20/142池，0.81%,CI：0.51-1.20），其次是T.Orientalis(19/142池，0.72%,CI:0.44-1.09),T.luwenshuni(9/142池，0.34%，CI：0.16-0.62），B.Ovis(4/142池，0.15%,CI：0.05-0.34）和Bo。Theileri(4/142池，0.15%,CI：0.05-0.34），埃里希亚·埃文吉(3/142游泳池，0.11%，CI：0.03-0.29），和babesiabigemina(1/142，0.04%，CI：0.00-0.16）。这项研究报告了T.luwenshuni的存在，E.艾文吉,还有Bo.泰莱里第一次在孟加拉国。这项研究的新发现是H.bispinosa中B.bigemina和E.ewingii的经卵巢传播的最重要文献，也为E.ewingii和Bo的存在提供了主要的分子证据。theileri在H.bispinosa。因此,这项研究可能揭示了自然环境中壁虱中循环的TBP，从而倡导了孟加拉国医生和兽医控制和预防TBD的意识。
