Laboratório de Vírus, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
Embrapa Pantanal, Corumbá, MS, Brasil.
Transbound Emerg Dis. 2021 Nov;68(6):3424-3432. doi: 10.1111/tbed.13946. Epub 2020 Dec 20.
The aetiological agent of equine infectious anaemia (EIA) is the retrovirus equine infectious anemia virus (EIAV) that infects all members of the Equidae family. The EIA is widely disseminated in the Brazilian territory with a high seroprevalence in the Brazilian Pantanal and is mainly diagnosed using agar gel immunodiffusion (AGID). There are few complete EIAV genome sequences available in GenBank, which had an impact on molecular detection studies. In this study, we conducted molecular detection and sequencing of EIAV proviral DNA from Brazilian horses. We analysed the genomic region from exon 1 of tat to gag (tat-gag). Comparative serological tests, comprising AGID and two enzyme-linked immunosorbent assays (ELISAs), were also conducted. Of the 133 samples, 58 were positive in the tat-gag PCR, and 49 nucleotide sequences of 272 bp were obtained. Using this developed tat-gag PCR EIAV proviral DNA was detected in 7% of the AGID-negative samples and 26% of the AGID-negative samples were positive in at least one of the ELISA tests used. Using phylogenetic analysis, the Brazilian Pantanal EIAV sequences grouped in a different clade of EIAV sequences from other countries. Thus, the EIAV sequences can contribute to the knowledge of the tat-gag genomic region in the circulating viruses in the Brazilian Pantanal, in addition to providing new information about the genetic diversity. In addition, the serological results demonstrate the greater sensitivity of the ELISAs used in this study compared to AGID for EIA diagnosis.
马传染性贫血（EIA）的病原体是感染马科动物所有成员的逆转录病毒马传染性贫血病毒（EIAV）。EIA 在巴西领土上广泛传播，在巴西潘塔纳尔地区的血清阳性率很高，主要通过琼脂凝胶免疫扩散（AGID）进行诊断。GenBank 中可用的完整 EIAV 基因组序列很少，这对分子检测研究产生了影响。在这项研究中，我们对巴西马的 EIAV 前病毒 DNA 进行了分子检测和测序。我们分析了从 tat 到 gag（tat-gag）外显子 1 的基因组区域。还进行了比较血清学测试，包括 AGID 和两种酶联免疫吸附测定（ELISA）。在 133 个样本中，58 个在 tat-gag PCR 中呈阳性，获得了 272bp 的 49 个核苷酸序列。使用这种开发的 tat-gag PCR，在 7%的 AGID 阴性样本中检测到 EIAV 前病毒 DNA，并且在至少一种使用的 ELISA 测试中，26%的 AGID 阴性样本呈阳性。通过系统发育分析，巴西潘塔纳尔 EIAV 序列与来自其他国家的 EIAV 序列聚集成不同的分支。因此，EIAV 序列可以为巴西潘塔纳尔地区循环病毒中 tat-gag 基因组区域的知识做出贡献，此外还提供了有关遗传多样性的新信息。此外，血清学结果表明，与 AGID 相比，本研究中使用的 ELISA 对 EIA 诊断的敏感性更高。
