Distinct avian influenza viruses found in Antarctic penguins

May 06, 2014
Aeron Hurt with a penguin. Credit: Aeron Hurt, WHO Collaborating Centre for Reference and Research on Influenza in Melbourne, Australia.

An international team of researchers has, for the first time, identified an avian influenza virus in a group of Adélie penguins from Antarctica. The virus, found to be unlike any other circulating avian flu, is described in a study published this week in mBio, the online open-access journal of the American Society for Microbiology.

While other research groups have taken blood samples from penguins before and detected influenza antibodies, no one had detected actual live influenza virus in penguins or other birds in Antarctica previously, says study author and Associate Professor Aeron Hurt, PhD, a senior research scientist at the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne, Australia.

For the study, Hurt and colleagues collected swabs from the windpipes and posterior openings of 301 Adélie penguins, and blood from 270 of those penguins, from two locations on the Antarctic Peninsula: Admiralty Bay and Rada Covadonga. The samples were collected during January and February 2013.

Using a laboratory technique called real-time reverse transcription-PCR, the researchers found (AIV) genetic material in eight (2.7%) samples, six from adult penguins and two from chicks. Seven of the samples were from Rada Covadonga. The researchers were able to culture four of these viruses, demonstrating that live infectious virus was present. On further analysis of the samples, the researchers found all viruses were H11N2 influenza viruses that were highly similar to each other.

But when the researchers compared the full genome sequences of four of the collected viruses to all available animal and human sequences in public databases, "we found that this virus was unlike anything else detected in the world," says Hurt. "When we drew phylogenetic trees to show the evolutionary relationships of the virus, all of the genes were highly distinct from contemporary AIVs circulating in other continents in either the Northern or Southern Hemisphere."

Four of the gene segments were most closely related to North American avian lineage viruses from the 1960s to 1980s. Two genes showed a distant relationship to a large number of South American AIVs from Chile, Argentina and Brazil. Using a molecular clock to incorporate the evolutionary rate of each AIV gene segment, the researchers estimated that the virus has been evolving for the past 49 to 80 years without anyone knowing about it. Whether this evolution has occurred exclusively in Antarctica is currently unknown, Hurt says.

Additional experiments found that 16% of penguins (43 of 270) had influenza A antibodies in their blood, and that the newly identified virus is likely to be exclusive to birds, as it did not readily infect a group of ferrets used as a test to see if the virus could infect mammals.

While the virus did not cause illness in the , the study shows that " viruses can get down to Antarctica and be maintained in penguin populations," Hurt says. "It raises a lot of unanswered questions," including how often AIVs are being introduced into Antarctica, whether it is possible for highly pathogenic AIVs to be transferred there, what animals or ecosystems are maintaining the , and whether the are being cryopreserved during the winters.

Explore further: New avian influenza sampling method saves money

add to favorites email to friend print save as pdf

Related Stories

Influenza virus in wild birds in Norway

Sep 12, 2013

Ducks and gulls are the natural hosts of influenza A virus. Ragnhild Tønnessen's PhD research project has characterised influenza A viruses in gulls and ducks in Norway.

Pigs in southern China infected with avian flu

Dec 19, 2012

Researchers report for the first time the seroprevalence of three strains of avian influenza viruses in pigs in southern China, but not the H5N1 avian influenza virus. Their research, published online ahead of print in the ...

Sea otters can get the flu, too

Apr 08, 2014

Northern sea otters living off the coast of Washington state were infected with the same H1N1 flu virus that caused the world-wide pandemic in 2009, according to a new U.S. Geological Survey and Centers for ...

Recommended for you

Research sheds light on what causes cells to divide

Dec 24, 2014

When a rapidly-growing cell divides into two smaller cells, what triggers the split? Is it the size the growing cell eventually reaches? Or is the real trigger the time period over which the cell keeps growing ...

Locking mechanism found for 'scissors' that cut DNA

Dec 24, 2014

Researchers at Johns Hopkins have discovered what keeps an enzyme from becoming overzealous in its clipping of DNA. Since controlled clipping is required for the production of specialized immune system proteins, ...

Scrapie could breach the species barrier

Dec 24, 2014

INRA scientists have shown for the first time that the pathogens responsible for scrapie in small ruminants (prions) have the potential to convert the human prion protein from a healthy state to a pathological ...

Extracting bioactive compounds from marine microalgae

Dec 24, 2014

Microalgae can produce high value health compounds like omega-3s , traditionally sourced from fish. With declining fish stocks, an alternative source is imperative. Published in the Pertanika Journal of Tr ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.