M'ghirbi Youmna, Bèji Marwa, Oporto Beatriz, Khrouf Fatma, Hurtado Ana, Bouattour Ali
Université Tunis El Manar, Institut Pasteur de Tunis, Laboratoire d'Epidémiologie et de Microbiologie Vétérinaire, Service d'Entomologie Médicale, 1002, Tunis-Belvédère, Tunisia.
Department of Animal Health, NEIKER - Instituto Vasco de Investigación y Desarrollo Agrario, Berreaga 1, 48160, Derio, Bizkaia, Spain.
Parasit Vectors. 2016 Oct 20;9(1):556. doi: 10.1186/s13071-016-1840-7.
Tick-borne diseases caused by Anaplasma species put serious constraints on the health and production of domestic cattle in tropical and sub-tropical regions. After recovering from a primary infection, cattle typically become persistent carriers of pathogens and play a critical role in the epidemiology of the disease, acting as reservoirs of the Anaplasma spp.
In this study a duplex PCR assay was used for the simultaneous detection of Anaplasma marginale and Anaplasma phagocytophilum in cattle using two primer pairs targeting msp4 and msp2 genes, respectively. We used this method to analyze DNA preparations derived from 328 blood cattle samples that were collected from 80 farms distributed among Tunisia's four bioclimatic zones.
The prevalence of the A. marginale infection (24.7 %) was significantly higher and more widespread (in all bioclimatic areas) than that of A. phagocytophilum (0.6 %), which was found in a mixed infection with A. marginale.
The duplex PCR assay used proved to be a rapid, specific and inexpensive mean for the simultaneous detection of Anaplasma marginale and Anaplasma phagocytophilum in cattle blood. It allowed us to report the identification of A. phagocytophilum for the first time in cattle in Tunisia and confirm the presence of A. marginale in cattle from several geographical areas of the country. Further epidemiological studies undertaken using this assay will help improve the surveillance of the associated diseases in the regions where they are endemic.
由无形体属物种引起的蜱传疾病严重限制了热带和亚热带地区家牛的健康和生产。牛在初次感染康复后，通常会成为病原体的持续携带者，并在疾病流行病学中发挥关键作用，充当无形体属的宿主。
在本研究中，采用双重PCR检测法，分别使用针对msp4和msp2基因的两对引物，同时检测牛体内的边缘无形体和嗜吞噬细胞无形体。我们用这种方法分析了从突尼斯四个生物气候区的80个农场采集的328份牛血样本的DNA提取物。
边缘无形体感染率（24.7%）显著高于嗜吞噬细胞无形体（0.6%），且分布更广泛（在所有生物气候区均有发现），嗜吞噬细胞无形体是在与边缘无形体的混合感染中发现的。
事实证明，所采用的双重PCR检测法是一种快速、特异且廉价的方法，可同时检测牛血液中的边缘无形体和嗜吞噬细胞无形体。它使我们首次在突尼斯的牛身上鉴定出嗜吞噬细胞无形体，并证实了该国几个地理区域的牛体内存在边缘无形体。使用该检测法进行的进一步流行病学研究将有助于改善这些疾病流行地区对相关疾病的监测。
