National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan; Zanzibar Livestock Research Institute, Ministry of Agriculture, Natural Resources, Livestock and Fisheries, P. o. Box. 159, Zanzibar, Tanzania.
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Acta Trop. 2020 Nov;211:105598. doi: 10.1016/j.actatropica.2020.105598. Epub 2020 Jun 24.
Tick-borne diseases (TBDs) are serious constraints to livestock production in Tanzania and other tropical and subtropical countries and impact the livelihoods of resource-poor farming communities in the region. In Tanzania, detailed studies on tick-borne pathogens (TBPs) in cattle using sensitive molecular detection methods are scarce. The objective of this study was to investigate the occurrence and species composition of bovine TBPs in cattle kept in Zanzibar Island. A total of 236 blood samples were randomly collected in cattle population in June and July 2019. We used polymerase chain reaction (PCR) and gene sequencing to detect and identify pathogens. PCR screening of all 236 samples revealed that 64.5% of animals were infected by TBPs, including Theileria parva (34.3%), T. mutans (38.1%), T. taurotragi (30.9%), Anaplasma marginale (10.2%), Babesia bigemina (5.1%), T. velifera (3.4%) and B. bovis (2.1%). Overall a total of 86 animals (36.4%) were co-infected with up to five pathogens including T. parva, T. mutans, T. taurotragi, A. marginale and B. bigemina. The pathogens mostly involved in the co-infection were T. parva, T. taurotragi and T. mutans. Sequence analysis indicated that T. parva p104 and B. bigemina RAP1a genes are diverse among the sampled animals in Zanzibar Island, with 99.64%-100% and 99.51%-100% nucleotide sequence identity value respectively. In contrast, the A. marginale MSP-5, T. mutans 18S rRNA V4 region and B. bovis SBP-2 genes are conserved, with 100%, 99.05%-100% and 99.66%-100% nucleotide sequence identity values respectively. The phylogenetic analyses revealed that T. parva p104 and B. bigemina RAP1a gene sequences showed significant differences of genotypes, as they appear in different clades. Meanwhile, A. marginale MSP-5, T. mutans 18S rRNA V4 region and B. bovis SBP-2 gene sequences appear in the same clade with other sequences extracted from the NCBI GenBank. The epidemiological findings revealed in this study will provide important information on tick-borne diseases in Tanzania and will be used as scientific basis for planning future control strategies.
在坦桑尼亚和其他热带和亚热带国家，蜱传疾病（TBDs）严重制约着畜牧业生产，并影响着该地区资源贫乏的农民社区的生计。在坦桑尼亚，使用敏感的分子检测方法对牛的蜱传病原体（TBPs）进行详细研究很少见。本研究的目的是调查在桑给巴尔岛饲养的牛中牛蜱传病原体的发生和种组成。2019 年 6 月和 7 月，我们在牛群中随机采集了 236 份血样。我们使用聚合酶链反应（PCR）和基因测序来检测和鉴定病原体。对所有 236 个样本进行的 PCR 筛查显示，64.5%的动物受到 TBPs 的感染，包括卵形泰勒虫（34.3%）、分歧泰勒虫（38.1%）、环形泰勒虫（30.9%）、边缘无浆体（10.2%）、双芽巴贝斯虫（5.1%）、泰勒虫（3.4%）和牛巴贝斯虫（2.1%）。总的来说，共有 86 只动物（36.4%）同时感染了多达五种病原体，包括卵形泰勒虫、分歧泰勒虫、环形泰勒虫、边缘无浆体和双芽巴贝斯虫。最常参与共感染的病原体是卵形泰勒虫、环形泰勒虫和分歧泰勒虫。序列分析表明，桑给巴尔岛采样动物的卵形泰勒虫 p104 和双芽巴贝斯虫 RAP1a 基因存在多样性，核苷酸序列同一性值分别为 99.64%-100%和 99.51%-100%。相比之下，边缘无浆体 MSP-5、分歧泰勒虫 18S rRNA V4 区和牛巴贝斯虫 SBP-2 基因保守，核苷酸序列同一性值分别为 100%、99.05%-100%和 99.66%-100%。系统发育分析表明，卵形泰勒虫 p104 和双芽巴贝斯虫 RAP1a 基因序列在基因型上存在显著差异，因为它们出现在不同的分支中。同时，边缘无浆体 MSP-5、分歧泰勒虫 18S rRNA V4 区和牛巴贝斯虫 SBP-2 基因序列与从 NCBI GenBank 提取的其他序列出现在同一分支中。本研究揭示的流行病学发现将为坦桑尼亚的蜱传疾病提供重要信息，并将作为规划未来控制策略的科学依据。
