Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Evidence of host adaptation of avian-origin influenza A virus

15.05.2013
A novel avian-origin reassortant influenza A (H7N9) virus emerged in China in February 2013, and is associated with severe lower respiratory tract diseases.

To date, more than 100 human cases of infection, including at least 20 deaths, have been reported in China. Three early cases of infection were described in Hangzhou, Zhejiang Province, China.

The general clinical features of the three patients were similar to the previously reported cases in China. Two of the three patients had a history of direct contact with live poultry markets. Interestingly, poultry cage swabs and feces from the free market visited by Patient 2 one week prior to the onset of symptoms were positive for the novel avian influenza A (H7N9) virus. This indicates a direct connection between human infection with the novel H7N9 virus and an environmental source.

Researchers analyzed the DNA sequences from the Hangzhou viruses and other human H7N9 viral sequences available from the databases, together with those from other H7 influenza viruses. This showed that the virus sequenced from Patient 2 was most closely related to the virus derived from the environmental source associated with Patient 2, while Hangzhou/1 and Hangzhou/3 were more divergent. These data suggest that several H7N9 viruses are circulating in Hangzhou. It is uncertain whether the diversity of H7N9 in Hangzhou is the result of host adaptation, or predates the transmission to humans from an avian source.

The pathogenesis of the novel avian-origin H7N9 virus in humans remains unknown, although a series of substitutions that have been confirmed as pathogenicity factors in animal models were found in viruses from Hangzhou. A glutamine to isoleucine substitution was observed at position 226 of the hemagglutinin amino acid sequence in the newly sequenced virus. Isoleucine has similar characteristics to leucine, which was previously shown to be a pivotal amino acid in the binding of avian- or human-type receptor, and might be essential for pathogenicity in cases of airborne viral transmission. This substitution was observed for the first time at this site in H7N9, which may indicate a novel host adaptation feature of the H7 virus.

Findings from the current study implied a rapid evolution of the novel H7N9 virus. This may assist in determining the source and mode of transmission of these infections, and provide a reference for selecting candidate vaccine strains. The receptor binding properties of Q226I and the significance of the substitutions in H7N9 need further exploration, including both in vitro and in vivo experiments, and extensive field surveillance.

Funder: Hangzhou Key Medicine Discipline Fund for Public Health Laboratory sponsored by the Hangzhou Government, China Ministry of Science and Technology Project 973 (grant nos. 2010CB530303 and 2011CB504703), and an intramural special grant for influenza virus research from the Chinese Academy of Sciences (KSZD-EW-Z-002).

Corresponding authors:

PAN JingCao
jingcaopan@gmail.com
LIU Jun
liuj333@gmail.com
See the article:
Li J, Yu X F, Pu X Y, et al. Environmental connections of novel avian-origin H7N9 influenza virus infection and virus adaptation to the human. Sci China Life Sci, 2013, 56(6), 485-492. doi: 10.1007/s11427-013-4491-3

http://life.scichina.com:8082/sciCe/EN/10.1007/s11427-013-4491-3

Science China Press Co., Ltd. (SCP) is a scientific journal publishing company of the Chinese Academy of Sciences (CAS). For 50 years, SCP takes its mission to present to the world the best achievements by Chinese scientists on various fields of natural sciences researches.

YAN Bei | EurekAlert!
Further information:
http://www.scichina.org

Further reports about: Chinese herbs DNA sequence H7N9 amino acid influenza virus natural science

More articles from Health and Medicine:

nachricht Study suggests possible new target for treating and preventing Alzheimer's
02.12.2016 | Oregon Health & Science University

nachricht The first analysis of Ewing's sarcoma methyloma opens doors to new treatments
01.12.2016 | IDIBELL-Bellvitge Biomedical Research Institute

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>