Cornell microbiologists have shown that a single amino acid variation in an enzyme that is part of the DNA copying process of equid herpesvirus type 1 (EHV-1) creates a different type of EHV-1, which causes the neurological disorders in horses. Both types of EHV-1 can also cause abortions.
The researchers' paper is published in the Nov. 9 issue of PLoS Pathogens, published by the Public Library of Science.
The horse herpes virus, a close relative of the chickenpox virus in humans, lives in horses' nostrils and is commonly spread by droplets in the air. And horses remain infected for life. Recently, veterinarians noticed a rise in outbreaks of the neurological form of EHV-1, which can devastate entire herds. Close to one-third of horses that develop the neurological disease end up dying or being euthanized.
"There are apparently two distinct pathotypes of EHV-1 out there, and one is more likely than the other to cause the neurological disease. This study provides the ultimate proof," said Klaus Osterrieder, the paper's senior author who is professor of virology in the Department of Microbiology and Immunology in Cornell's College of Veterinary Medicine. Laura Goodman, who was a graduate student in the Osterrieder laboratory and is now a postdoctoral associate at Cornell's Baker Institute for Animal Health, is the paper's lead author.
After cloning the genome of the virus obtained from a mare that had both lost a fetus and developed neurological symptoms, the researchers then altered one amino acid in the viral enzyme known as DNA polymerase and rendered the virus unable to cause neurological disease. The amino acid change reduced levels of the virus in the horse's bloodstream, and lower levels of the virus reached the central nervous system. The mutation also made the virus more susceptible to antiviral drugs. The researchers believe the reduced replication and levels of virus in the blood may be why one form of the virus does not cause neurological disorders.
"The two pathotypes replicate to similar levels in the horse's nose and spread to other horses with similar efficiency, so interventions should be equally rigorous for all infections," said Osterrieder.
The fact that EHV-1 is a virus and, thus, does not respond to antibiotics underscores the need for prevention, which includes limiting contact and using separate feeders for infected horses. Also, handlers should be careful not to transfer the virus with their clothes, shoes, hands and gear. While vaccines are available that create an immune response against the EHV-1 respiratory disease, no vaccine is currently known to efficiently protect horses against the neurological disease. Only a few vaccines were shown to protect against abortion.
The researchers postulate that herpes viruses evolve toward strains that produce less disease, so they think that the more virulent neurological strain is older than the milder type of EHV-1.
Krishna Ramanujan | EurekAlert!
More genes are active in high-performance maize
19.01.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn
How plants see light
19.01.2018 | Albert-Ludwigs-Universität Freiburg im Breisgau
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy