Obaid Muhammad Kashif, Ren Qiaoyun, Zan Xiaoqing, Luo Jin, Zeb Jehan, Rashid Muhammad, Liu Guangyuan, Yang Laikang, Yun Xiujun, Ma Lijun, Ma Peng, Ma Changchun, Yang Xiaomei, Yin Hong, Guan Guiquan
State Key Laboratory for Animal Disease Control and Prevention, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, China.
Hebei Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology, Hebei Collaborative Innovation Center for Eco-Environment, Ministry of Education Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China.
FASEB J. 2025 Aug 15;39(15):e70907. doi: 10.1096/fj.202501223RRR.
Haemaphysalis longicornis is associated with the transmission of 30 various types of pathogens, having medical and veterinary importance. Hence, this study was designed to investigate the prevailing pathogen in Zhangjiachuan county, Gansu province, China. For the said purpose, we performed a molecular investigation of Rickettsia and Piroplasms pathogens in morpho-molecularly confirmed H. longicornis tick species, collected from cattle in the study area. Furthermore, the efficacy of deltamethrin was evaluated using larval packet tests (LPTs) against this tick species, followed by molecular and in silico analysis of voltage-gated sodium channels (VGSCs) gene. Moreover, their amplified VGSCs genes (Domain II and a part of its linker region with Domain III) were comparatively aligned with insecticide-susceptible Rhipicephalus (Rh) microplus (AF134216.2, OQ349192.1, KM073932.1), Rh. sanguineus (KU886031.1) and resistant Rh. microplus (MH986341.1, KM073928.1, KM073930.1, KM073931.1, KM073933.1), Rh. annulatus (MN535171.1), and Rh. appendiculatus (MH053429.1). Our findings revealed 149/469 (31.77%) and 92/469 (19.62%) prevalence rates of single infection for Candidatus Rickettsia jingxinensis (via 17-KDa and ompB genes) and Theileria orientalis (via 18S rRNA gene), respectively. Additionally, LPTs results expressed diverse mortality rates of 8.17%, 17.63%, 22.26%, 43.18%, 73.46%, and 87.51% via the application of 0.00006, 0.0006, 0.006, 0.06, 0.6, and 6 mg/mL deltamethrin concentrations, respectively, indicating the presence of reduced susceptible larvae in the targeted region. Comparative alignment of VGSCs gene (domain-II) showed 29 single nucleotide polymorphisms (SNPs) including 5 nonsynonymous (NS) SNPs. All five NS-SNPs were in the linker regions, playing a crucial role in protein channels (VGSCs) formation. Whereas comparison of the obtained partial domain-III of VGSCs gene with Rh. microplus and Rh. sanguineus tick species showed 100% conservativeness as no SNP was identified in its domain-III. In silico analysis regarding the 3D structure of VGSCs protein revealed suitability for attachment of deltamethrin and recorded binding affinity was -524.58 kcal/mol. This study presented the first ever molecular report of VGSC gene of H. longicornis tick species which will be helpful in their management as well as to mitigate their negative impacts.
长角血蜱与30种不同类型病原体的传播有关，具有医学和兽医学重要性。因此，本研究旨在调查中国甘肃省张家川县流行的病原体。为此，我们对从研究区域的牛身上采集的形态分子学确认的长角血蜱蜱种中的立克次氏体和梨形虫病原体进行了分子调查。此外，使用幼虫包囊试验（LPTs）评估了溴氰菊酯对该蜱种的效力，随后对电压门控钠通道（VGSCs）基因进行了分子和计算机模拟分析。此外，将它们扩增的VGSCs基因（结构域II及其与结构域III的连接区域的一部分）与对杀虫剂敏感的微小扇头蜱（Rh）（AF134216.2、OQ349192.1、KM073932.1）、血红扇头蜱（Rh. sanguineus）（KU886031.1）以及抗性微小扇头蜱（MH986341.1、KM073928.1、KM073930.1、KM073931.1、KM073933.1）、环形扇头蜱（Rh. annulatus）（MN535171.1）和附加扇头蜱（Rh. appendiculatus）（MH053429.1）进行了比较比对。我们的研究结果显示，新金氏立克次氏体（通过17-kDa和ompB基因）和东方泰勒虫（通过18S rRNA基因）的单感染患病率分别为149/469（31.77%）和92/469（19.62%）。此外，LPTs结果显示，通过分别应用0.00006、0.0006、0.006、0.06、0.6和6 mg/mL的溴氰菊酯浓度，死亡率分别为8.17%、17.63%、22.26%、43.18%、73.46%和87.51%，表明目标区域存在对溴氰菊酯敏感性降低的幼虫。VGSCs基因（结构域II）的比较比对显示有29个单核苷酸多态性（SNP），包括5个非同义（NS）SNP。所有5个NS-SNP都在连接区域，在蛋白质通道（VGSCs）形成中起关键作用。而将获得的VGSCs基因部分结构域III与微小扇头蜱和血红扇头蜱蜱种进行比较，发现其结构域III中未鉴定出SNP，具有100%的保守性。关于VGSCs蛋白三维结构的计算机模拟分析显示溴氰菊酯适合附着，记录的结合亲和力为-524.58 kcal/mol。本研究首次报道了长角血蜱蜱种VGSC基因的分子报告，这将有助于对其进行管理并减轻其负面影响。
