Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Zoos exonerated in baby elephant deaths; Data support new branch of herpesvirus family

09.10.2014

Elephants are among the most intelligent non-humans, arguably on par with chimps, but both African and Asian elephants—separate species—are endangered.

In 1995, 16-month old Kumari, the first Asian elephant born at the National Zoo in Washington, DC, died of a then-mysterious illness. In 1999, Gary Hayward of Johns Hopkins University and collaborators published their results identifying a novel herpesvirus, EEHV1 as the cause of Kumari's sudden death.


Kumari, an Asian elephant at the National Zoo, died suddenly at 16 months of EEHV.

Credit: Jessie Cohen, Smithsonian's National Zoo

They now show that severe cases like this one are caused by viruses that normally infect the species, rather than by viruses that have jumped from African elephants, which was their original hypothesis. Hayward's latest research appears ahead of print in two concurrently published papers in the Journal of Virology.

At the time of Kumari's death, anti-zoo activists seized on the situation to call for abandoning all efforts to breed Asian elephants in zoos, as they claimed that zoos were spreading the deadly herpesvirus, says Hayward. Contrary to that, in the current research, "We showed that whereas some identical herpesvirus strains infected both healthy and diseased animals concurrently at particular facilities, the majority were different strains, and there has not been a single proven case of the same strain occurring at any two different facilities," says Hayward.

"Therefore, the viruses have not spread between zoos, and the sources of the viruses were most likely wild-born elephant herdmates. In fact, we also found the same disease in several Asian range countries, including in orphans and wild calves, and showed that the EEHV1 strains in India displayed the same genetic diversity as those in Western zoos."

The papers also provide substantial data to support the hypothesis that the EEHV collectively represent a new, fourth major branch of the herpesvirus family, the proposed deltaherpesvirus subfamily (Deltaherpesvirinae), says Philip Pellett of Wayne State University, Detroit, who wrote an invited Commentary which accompanied Hayward's papers. "Given that the three other branches were recognized over 30 years ago, establishment of a new subfamily would a big deal."

Pellett adds that "Further scientific significance arises from the discovery of 12 new herpesviruses and identification of some new wrinkles in our understanding of herpesvirus diversity and evolution."

In these studies, the investigators performed extensive DNA fingerprinting of the genetic signatures of all the known EEHV cases, as well as samples of EEHV virus that were obtained from wild Asian and African elephants, says Hayward. In the process, they identified seven different species of EEHVs and multiple different chimeric subtypes and strains of each.

"Because these viruses cannot be grown in cell culture, we had to develop sensitive and specific PCR techniques to be able to identify and compare the sequences of multiple segments of many different types of EEHV genomes directly from pathological blood and tissue DNA samples," says Hayward.

"Later, by also examining benign lung nodules from culled wild African elephants, we determined that EEHV2, EEHV3, EEHV6, and EEHV7 are natural endogenous viruses of African elephants, whereas EEHV1A, EEHV1B, EEHV4, and EEHV5 are apparently natural and nearly ubiquitous infections of Asian elephants that are occasionally shed in trunk washes and saliva of most healthy asymptomatic adult animals."

Hayward notes that only one example of a lethal cross-species infection with EEHV3 into an Asian elephant calf has been observed, and that the viruses causing disease normally do so only in their natural hosts.

Close monitoring of Asian elephant calves in zoos has so far enabled life-saving treatment for at least nine infected Asian calves, says Hayward, suggesting that such monitoring may ultimately enable determining why some animals become susceptible to severe disease after their primary EEHV1 infections, while most do not. "About 20% of all Asian elephant calves are susceptible to hemorrhagic disease, whereas symptomatic disease is extremely rare in African elephant calves under the same zoo conditions," says Hayward.

In another paper in the same issue of Journal of Virology, Hayward et al. demonstrate that the many highly diverged species and subtypes of EEHVs are ancient viruses that evolved separately from all other known subfamilies of mammalian herpesviruses within the ancestor of modern elephants, beginning about 100 million years ago.

Philip Pellett, of Wayne State University School of Medicine, Detroit, praises both of Hayward's studies in this issue of the Journal of Virology: "The information gained in the new EEHV papers will be important for developing diagnostic tools for these viruses, and for developing therapeutic approaches to diseases caused by EEHV."

Elephant populations have been plummeting. African elephants declined roughly from 10 million to half a million during the 20th century, due largely to habitat destruction, and intense poaching has since further decimated their numbers. Asian elephants, once in the millions, now number less than 50,000. They are threatened mostly by habitat fragmentation. Poaching is not an issue since they lack tusks.

###

The full papers will appear in the December issue of the Journal of Virology.

Journal of Virology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.

Garth Hogan | Eurek Alert!

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>