Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Jaboticabal, SP, Brazil.
Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Jaboticabal, SP, Brazil.
Vet Parasitol Reg Stud Reports. 2020 Jul;21:100437. doi: 10.1016/j.vprsr.2020.100437. Epub 2020 Jul 18.
The Anaplasmataceae family is composed of obligatory intracellular Gram-negative bacteria transmitted by arthropod vectors. In Brazil, with the exception of Anaplasma marginale, little is known about the occurrence of other Anaplasma and Ehrlichia species infecting cattle. The present study aimed at investigating the occurrence of Anaplasma spp. and Ehrlichia spp. in beef cattle (Bos indicus) sampled in the Brazilian Pantanal, an area prone to periodic flooding and endemic for bovine trypanosomiasis. Blood samples from 400 cattle were collected and screened by PCR assays based on rrs and dsb genes from Anaplasma spp. and Ehrlichia spp., respectively. Positive samples for Anaplasma spp. were subjected to qPCR assays based on the msp-2 gene and nPCR based on the groEL gene. As a result, 4.75% (19/400) and 48.12% (167/347) were positive for Anaplasma platys and Ehrlichia minasensis, respectively. Besides, positivity of 56.75% (227/400) for A. marginale and seropositivity of 90.75% (363/400) for Trypanosoma vivax were found. A high rate of co-infection was observed (67.25%), from which the co-infection by A. marginale and E. minasensis was more frequently found in calves than cows. Interestingly, none of the animals presenting co-infection showed anemia or other clinical signs. The present study showed, for the first time, the occurrence of A. platys and E. minasensis in beef cattle in the southern Pantanal, as well as a high rate of co-infection by A. marginale, E. minasensis and T. vivax in the sampled animals.
立克次体科由节肢动物传播的专性细胞内革兰氏阴性细菌组成。在巴西，除了边缘无浆体（Anaplasma marginale）外，人们对感染牛的其他无浆体和埃立克体物种的发生知之甚少。本研究旨在调查在巴西潘塔纳尔（Pantanal）地区采集的肉牛（Bos indicus）中是否存在无浆体属和埃立克体属。潘塔纳尔地区易受周期性洪水和牛锥虫病影响。从 400 头牛采集血液样本，并通过分别基于无浆体属和埃立克体属的 rrs 和 dsb 基因的 PCR 检测进行筛选。对无浆体属阳性样本进行基于 msp-2 基因的 qPCR 检测和基于 groEL 基因的 nPCR 检测。结果，4.75%（19/400）和 48.12%（167/347）的样本对平体无浆体（Anaplasma platys）和埃立克体属 Minasensis 呈阳性。此外，A. marginale 的阳性率为 56.75%（227/400），锥虫（Trypanosoma vivax）的血清阳性率为 90.75%（363/400）。观察到高比例的混合感染（67.25%），其中牛犊比母牛更容易出现 A. marginale 和 E. minasensis 的混合感染。有趣的是，没有任何表现出混合感染的动物出现贫血或其他临床症状。本研究首次在南部潘塔纳尔的肉牛中发现了平体无浆体和埃立克体属 Minasensis 的存在，以及在采样动物中 A. marginale、E. minasensis 和 T. vivax 的高混合感染率。
