Desenvolvimento de Teste Molecular para Detecção da Anemia Infecciosa Equina a partir da Análise Genômica de Amostras Brasileiras de EIAV

Abstract

Equine Infectious Anemia (EIA) is a disease of great importance in Equine Health, both due to losses lost to the mandatory euthanasia of these animals in certain provisions and due to the loss of health of these animals. EIA has a worldwide distribution, is one of eleven equine diseases that require compulsory notification to the World Organization for Animal Health (WOAH) and in Brazil is included among the diseases subject to measures provided for in the Animal Health Defense Regulation - MAPA - (Federal Decree 24.548 /1934). Despite the great economic importance of equine culture, there is no treatment or vaccine described for EIA and a molecular test for its detection has not yet been widely established. Considering the importance of this sector in Brazil, the genomic study of Brazilian EIAV isolates is noteworthy and can serve as a tool for the development of a molecular diagnosis, which would be of fundamental importance for early detection and consequent control of the disease. In this work, we performed massive and parallel sequencing of EIAV isolates using the SureSelect target enrichment system with next-generation sequencing (NGS) Illumina, from cDNA extracted from the blood of infected animals. The dangling sequences represent parts of the independent and accessory EIAV genes. Given the great difficulty in completely sequencing these isolates, it was necessary to use Sanger sequencing to complement the continuous sequences by NGS. One of the isolates obtained from a donkey sample that had its genome better characterized in the NGS was completely sequenced and is deposited in GenBank under the number ON615427. It was also possible to identify a conserved gene region among all isolated isolates from which we designed a qPCR assay that showed high detection power with an area under the ROC curve of 0.83, sensitivity values of 73.8% and specificity of 85.7%, it can be used as a molecular test for the diagnosis of EIA. Therefore, this work contributes to the study of the genetic diversity of Brazilian isolates and to the control of EIA in Brazil.