tetano
Editor, Senior Moderator
doi: 10.1128/mBio.01098-14 6 May 2014 mBio vol. 5 no. 3 e01098-14
Detection of Evolutionarily Distinct Avian Influenza A Viruses in Antarctica
Aeron C. Hurta,b,
Dhanasekaran Vijaykrishnac,
Jeffrey Butlera,
Chantal Baasa,b,
Sebastian Maurer-Strohd,e,f,
M. Carolina Silva-de-la-Fuenteg,
Gonzalo Medina-Vogelh,
Bjorn Olseni,
Anne Kelsoa,
Ian G. Barra,b,
Daniel Gonz?lez-Acu?ag
aWHO Collaborating Centre for Reference and Research on Influenza, North Melbourne, Victoria, Australia
bMonash University, School of Applied Sciences, Churchill, Victoria, Australia
cLaboratory of Virus Evolution, Duke-NUS Graduate Medical School, Singapore
dBioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Singapore
eNational Public Health Laboratory, Communicable Diseases Division, Ministry of Health, Singapore
fSchool of Biological Sciences (SBS), Nanyang Technological University (NTU), Singapore
gUniversidad de Concepci?n, Facultad de Ciencias Veterinarias, Chill?n, Chile
hFacultad de Ecolog?a y Recursos Naturales, Universidad Andr?s, Bello, Santiago, Chile
iMedical Sciences, Uppsala University, Uppsala, Sweden
Address correspondence to Aeron C. Hurt, aeron.hurt{at}influenzacentre.org.
Invited Editor Daniel Perez, VA-MD Regional College of Veterinary Medicine Editor Xiang-Jin Meng, Virginia Polytechnic Institute and State University
ABSTRACT
Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Ad?lie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lineage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment.
IMPORTANCE Avian influenza viruses (AIVs) are typically maintained and spread by migratory birds, resulting in the existence of distinctly different viruses around the world. However, AIVs have not previously been detected in Antarctica. In this study, we characterized H11N2 viruses sampled from Ad?lie penguins from two geographically different sites in Antarctica and show that the segmented AIV genome diverged between 49 and 80 years ago from other AIVs, with several genes showing similarity and shared ancestry with H3N8 equine influenza viruses. This study provides the first insight into the ecology of AIVs in Antarctica and highlights the potential risk of an introduction of highly pathogenic AIVs into the continent.
http://mbio.asm.org/content/5/3/e01098-14
Detection of Evolutionarily Distinct Avian Influenza A Viruses in Antarctica
Aeron C. Hurta,b,
Dhanasekaran Vijaykrishnac,
Jeffrey Butlera,
Chantal Baasa,b,
Sebastian Maurer-Strohd,e,f,
M. Carolina Silva-de-la-Fuenteg,
Gonzalo Medina-Vogelh,
Bjorn Olseni,
Anne Kelsoa,
Ian G. Barra,b,
Daniel Gonz?lez-Acu?ag
aWHO Collaborating Centre for Reference and Research on Influenza, North Melbourne, Victoria, Australia
bMonash University, School of Applied Sciences, Churchill, Victoria, Australia
cLaboratory of Virus Evolution, Duke-NUS Graduate Medical School, Singapore
dBioinformatics Institute (BII), Agency for Science, Technology and Research (A*STAR), Singapore
eNational Public Health Laboratory, Communicable Diseases Division, Ministry of Health, Singapore
fSchool of Biological Sciences (SBS), Nanyang Technological University (NTU), Singapore
gUniversidad de Concepci?n, Facultad de Ciencias Veterinarias, Chill?n, Chile
hFacultad de Ecolog?a y Recursos Naturales, Universidad Andr?s, Bello, Santiago, Chile
iMedical Sciences, Uppsala University, Uppsala, Sweden
Address correspondence to Aeron C. Hurt, aeron.hurt{at}influenzacentre.org.
Invited Editor Daniel Perez, VA-MD Regional College of Veterinary Medicine Editor Xiang-Jin Meng, Virginia Polytechnic Institute and State University
ABSTRACT
Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Ad?lie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lineage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment.
IMPORTANCE Avian influenza viruses (AIVs) are typically maintained and spread by migratory birds, resulting in the existence of distinctly different viruses around the world. However, AIVs have not previously been detected in Antarctica. In this study, we characterized H11N2 viruses sampled from Ad?lie penguins from two geographically different sites in Antarctica and show that the segmented AIV genome diverged between 49 and 80 years ago from other AIVs, with several genes showing similarity and shared ancestry with H3N8 equine influenza viruses. This study provides the first insight into the ecology of AIVs in Antarctica and highlights the potential risk of an introduction of highly pathogenic AIVs into the continent.
http://mbio.asm.org/content/5/3/e01098-14