Navigation Links
Evidence of host adaptation of avian-origin influenza A virus
Date:5/14/2013

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.


'/>"/>

Contact: YAN Bei
yanbei@scichina.org
86-106-400-8316
Science China Press
Source:Eurekalert

Related biology news :

1. Research reveals first evidence of hunting by prehistoric Ohioans
2. Strong scientific evidence that eating berries benefits the brain
3. UNH research adds to mounting evidence against popular pavement sealcoat
4. NIST/UMass study finds evidence nanoparticles may increase plant DNA damage
5. Evidence shows that anti-depressants likely do more harm than good, researchers find
6. Evidence of familial vulnerability for epilepsy and psychosis
7. New evidence that many genes of small effect influence economic decisions and political attitudes
8. DNA evidence shows that marine reserves help to sustain fisheries
9. New evidence in fructose debate: Could it be healthy for us?
10. Study provides first evidence of coevolution between invasive, native species
11. First direct evidence that elemental fluorine occurs in nature
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/20/2016)... 2016   Valencell , the leading innovator ... STMicroelectronics (NYSE: STM), a global semiconductor leader serving ... today the launch of a new, highly accurate ... includes ST,s compact SensorTile turnkey multi-sensor ... sensor system. Together, SensorTile and Benchmark deliver the ...
(Date:12/16/2016)... 16, 2016 The global wearable medical device market, in ... 2021 from USD 5.31 billion in 2016, at a CAGR of ... ... technological advancements in medical devices, launch of a growing number of ... connectivity among healthcare providers, and increasing focus on physical fitness. ...
(Date:12/15/2016)... 2016 Advancements in biometrics will ... and wellbeing (HWW), and security of vehicles ... passenger vehicles begin to feature fingerprint recognition, ... beat monitoring, brain wave monitoring, stress detection, ... pulse detection. These will be driven by ...
Breaking Biology News(10 mins):
(Date:1/19/2017)... HOUSTON , Jan. 19, 2017 ... formation of its Medical/Clinical Advisory Board.  This new ... who enhance the range and depth of expertise ... its novel prenatal diagnostic tests.  These experts are ... guidance for the company,s product development and commercialization ...
(Date:1/19/2017)... Research and Markets ... has announced the addition of the "Implantable Biomaterials ... report to their offering. Report Highlights: ... detailed analysis on current and future market trends to identify the investment ... as the base numbers Key market trends across the ...
(Date:1/19/2017)... ... January 19, 2017 , ... November Research ... leading biopharmaceutical and medical device manufacturers and regulators, is proud to announce the ... 11-compliant email client designed to provide product vigilance departments with the flexibility and ...
(Date:1/19/2017)... 19, 2017  ArmaGen, Inc., today announced that ... as chief executive officer, as well as a ... to ArmaGen more than 17 years of executive ... of biotherapeutics and pharmaceuticals. "Mathias ... experience and skillset necessary to lead ArmaGen to ...
Breaking Biology Technology: