Detection and molecular characterization of equine infectious anemia virus in Mongolian horses

Pathogenetic aspects of retroviral infections

Bovine leukemia and equine infectious anemia are registered in most regions of Ukraine and in many countries worldwide. This is accompanied by economic losses and reduced quality of livestock products, which determines the relevance of the study of retroviral infections, their diagnosis, and pathogenesis. The goal of our research was to find and improve the methodological foundations of the development of the pathological process for a more in-depth study of the etiology, pathogenesis, treatment, and prevention of retroviral infections. The object of the study was blood, lymph nodes, spleen, heart, lungs, liver, and kidneys for bovine leukemia and equine infectious anemia. Hematological, anatomical, histological, histochemical, morphometric, and statistical research methods were used for their study. The research group included 304 cattle aged 4–9 years and 42 horses, of which 25 were infected with the virus, and 17 were in the control group. It has been established that bovine leukemia and infectious anemia of horses is an irreversible pathological process characterized by slow progression, the presence of a latent or persistent form, with damage to cells, organs, and systems of the body, which leads to death. Infectious anemia of horses differs from leukemia of cattle by the hidden course of the pathological process. The pathogenesis of leukemia occurs in six stages, which we have identified and conventionally named.

Identification and genetic characterization of equine infectious anemia virus in Western Balkans

BACKGROUND

Equine infectious anemia (EIA) is a viral disease, caused by the Equine Infectious Anemia virus (EIAV) belonging to the Retroviridae family, genus Lentivirus. Horses (or equids) infected with EIAV are lifelong carriers and they remain contagious for other horses even in the absence of clinical signs. So far, EIAV infection has been reported among horses in North and South America, France, Germany, Italy, Hungary and Romania, with no publication regarding the presence of EIAV in horses in Serbia. To determine the circulation of EIAV among, approximately, the 5000 horses of the Vojvodina region, northern part of Serbia, 316 serum undergone serological testing for EIA. Then, identification and full genome sequencing using next generation sequencing was performed from one EIA positive horse.

RESULTS

the 316 sera were tested with 3 different commercial agar gel immunodiffusion (AGID) tests and two different commercial enzyme-linked immunosorbent assay (ELISA). With the three AGID kits, 311 (98.4%) among the 316 tested sera were negative and only five (1.6%) sera were positive for EIA. Some discrepancies were seen for the two ELISA kits tested since one exhibited the same results as AGID test and the second gave 295 sera with negative results, five with a positive result and 16 with doubtful outcome. Phylogenetic analysis performed using the full genome sequence showed that EIAV characterized from a horse in Serbia is different from those identify so fare around the world and form a distinct and separate group together with another EIAV strain.

CONCLUSIONS

This study demonstrate for the first time that EIAV is circulating at a low level in the horse population from the Northern part of Serbia. Interestingly, phylogenetic data indicates that this EIAV from the western Balkan region of Europe belongs to a new cluster.

Surveillance of the equine infectious anemia virus in Eastern and Central Saudi Arabia during 2014-2016

Background

Equine infectious anemia virus (EIAV) is one of the most important threats to the equine industry globally. This is due to the poor performance of the affected horses, which requires euthanization of the infected animals upon the infection confirmation. Infected animals remain carriers throughout their life. EIAV infection has been reported in many parts of the world, including North America, Europe, Asia, and Africa. However, the EIAV status is never assessed in horses in the Gulf area, especially in the Kingdom of Saudi Arabia (KSA).

Aim

This study aimed to perform molecular and serological surveillance among some horse populations in Eastern and Central Saudi Arabia.

Materials and Methods

Sera and whole blood were collected from 361 horses and 19 donkeys from the eastern and central regions of Saudi Arabia during January 2014-December 2016. Sera were tested by the commercial EIAV enzyme-linked immunosorbent assay kits. Moreover, the collected blood samples were tested by the commercial real-time polymerase chain reaction kits.

Results

Our serological surveillance revealed the absence of any antibodies against EIAV in the tested animals. Similar results were reported for the tested horses' plasma. This study confirms the absence of EIAV in horses and donkeys from Eastern and Central Saudi Arabia during the tenure of the current study. However, careful monitoring of the EIAV is highly recommended to avoid the emergence of such a virus in the horse population in Saudi Arabia.

Conclusion

To the best of our knowledge, this is the first EIAV surveillance conducted not only in Saudi Arabia but also in the Gulf area. This study confirms the absence of EIAV in the tested equine population in the eastern and central regions of Saudi Arabia during 2014-2016.

Comparative population genomics unveils candidate genes for athletic performance in Hanoverians

Equine athletes have a genetic heritage that has been evolved for millions of years, which provides an opportunity to study the genetics of locomotion pattern and performance in mammals. The Hanoverian, a breed originating in Germany, is arguably among the most athletic of horse breeds, as well as possessing a balanced character and beautiful appearance. Here, we compared the whole genomes of Hanoverian with three other horse breeds (Akhal-Teke, Franches-Montagnes, and Standardbred), using the fixation index (Fst) and cross-population composite likelihood ratio (XP-CLR) methods for testing the multi-locus allele frequency differentiation between populations. We identified 299 and 485 positively selected genes using the Fst and XP-CLR methods, respectively. Further functional analyses showed that the ACTA1 gene is potentially involved in athletic performance in the Hanoverian breed, consistent with its role observed in human population. In addition, three other loci on chromosomes 1 and 20 were identified to be potentially involved in equine physical performance. The selected candidate genes identified in this study may be useful in current breeding efforts to develop improved breeds in regard to athletic performance.