Jirapattharasate Charoonluk, Adjou Moumouni Paul Franck, Cao Shinuo, Iguchi Aiko, Liu Mingming, Wang Guanbo, Zhou Mo, Vudriko Patrick, Changbunjong Tanasak, Sungpradit Sivapong, Ratanakorn Parntep, Moonarmart Walasinee, Sedwisai Poonyapat, Weluwanarak Thekhawet, Wongsawang Witsanu, Suzuki Hiroshi, Xuan Xuenan
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.
Department of Pre-clinic and Applied Animal Science, Faculty of Veterinary Science, Mahidol University, Salaya, Nakhon Pathom 73170, Thailand.
Parasitol Int. 2016 Feb;65(1):62-69. doi: 10.1016/j.parint.2015.10.005. Epub 2015 Oct 22.
Beef cattle production represents the largest cattle population in Thailand. Their productivity is constrained by tick-borne diseases such as babesiosis and theileriosis. In this study, we determined the prevalence of Babesia bigemina, Babesia bovis and Theileria orientalis using polymerase chain reaction (PCR). The genetic markers that were used for detection of the above parasites were sequenced to determine identities and similarity for Babesia spp. and genetic diversity of T. orientalis. Furthermore the risk factors for the occurrence of the above protozoan parasites in beef cattle from northern and northeastern parts of Thailand were assessed. A total of 329 blood samples were collected from beef cattle in 6 provinces. The study revealed that T. orientalis was the most prevalent (30.1%) parasite in beef cattle followed by B. bigemina (13.1%) and B. bovis (5.5%). Overall, 78.7% of the cattle screened were infected with at least one of the above parasites. Co-infection with Babesia spp. and T. orientalis was 30.1%. B. bigemina and T. orientalis were the most prevalent (15.1%) co-infection although triple infection with the three parasites was observed in 3.0% of the samples. Sequencing analysis revealed that B. bigemina RAP1 gene and B. bovis SBP2 gene were conserved among the parasites from different cattle samples. Phylogenetic analysis showed that the T. orientalis MPSP gene from parasites isolated from cattle in north and northeast Thailand was classified into types 5 and 7 as reported previously. Lack of tick control program was the universal risk factor of the occurrence of Babesia spp. and T. orientalis infection in beef cattle in northern and northeastern Thailand. We therefore recommend training of farmers on appropriate tick control strategies and further research on potential vectors for T. orientalis and elucidate the effect of co-infection with Babesia spp. on the pathogenicity of T. orientalis infection on beef in northern and northeastern Thailand.
肉牛养殖是泰国牛群数量最多的养殖类型。它们的生产力受到诸如巴贝斯虫病和泰勒虫病等蜱传疾病的制约。在本研究中，我们使用聚合酶链反应（PCR）来测定双芽巴贝斯虫、牛巴贝斯虫和东方泰勒虫的流行率。对用于检测上述寄生虫的基因标记进行测序，以确定巴贝斯虫属的身份和相似性以及东方泰勒虫的遗传多样性。此外，还评估了泰国北部和东北部肉牛中上述原生动物寄生虫发生的风险因素。从6个省份的肉牛中总共采集了329份血样。研究表明，东方泰勒虫是肉牛中最普遍存在的（30.1%）寄生虫，其次是双芽巴贝斯虫（13.1%）和牛巴贝斯虫（5.5%）。总体而言，接受筛查的牛中有78.7%感染了上述至少一种寄生虫。巴贝斯虫属和东方泰勒虫的共感染率为30.1%。双芽巴贝斯虫和东方泰勒虫是最普遍的（15.1%）共感染类型，不过在3.0%的样本中观察到了三种寄生虫的三重感染。测序分析表明，不同牛样本中的寄生虫的双芽巴贝斯虫RAP1基因和牛巴贝斯虫SBP2基因是保守的。系统发育分析表明，从泰国北部和东北部牛中分离出的寄生虫的东方泰勒虫MPSP基因如先前报道的那样被分类为5型和7型。缺乏蜱虫控制计划是泰国北部和东北部肉牛中巴贝斯虫属和东方泰勒虫感染发生的普遍风险因素。因此，我们建议对农民进行适当蜱虫控制策略的培训，并进一步研究东方泰勒虫的潜在传播媒介，阐明巴贝斯虫属共感染对泰国北部和东北部肉牛东方泰勒虫感染致病性的影响。
