The influenza pandemic that began in Mexico in April 2009 rapidly spread throughout the world and arrived in Japan one month later. Now, a research team led by Toshihisa Ishikawa at the RIKEN Omics Science Center in Yokohama has revealed what a portion of the pandemic influenza virus looked like when it emerged in Japan, and how it has changed over time1. The findings will help to guide influenza vaccine development and will aid in preparations for future influenza pandemic outbreaks.
The researchers collected swab samples from the respiratory system of 253 individual flu sufferers in Osaka, Tokyo and Chiba, and sequenced the influenza genes encoding the proteins hemagglutinin (HA) and neuraminidase (NA). Although these genes represent only 10% of the influenza viral genome, they demonstrate more variability than other influenza genes, Ishikawa explains, so are likely to mediate any emerging changes in flu severity or antiviral drug resistance.
The sequencing showed that the pandemic influenza samples from the individuals in Japan fell into two groups: those that were collected at the time of the initial outbreak in May 2009, and those that were collected a few months later, during the most rapid spread of the virus throughout the country from October 2009 to January 2010.
Importantly, when the researchers compared the sequences between these two groups of viruses, they found that they fell into two totally separate clusters. This indicated that there were many differences between the two groups of pandemic influenza viruses, including the emergence of a mutation in an important site—the so-called ‘Ca antigen site’ of HA—that is known to be subject to pressure by the immune system. This mutation, as well as some others that the researchers identified, may account for the more rapid spread of the pandemic influenza virus later in the year.
Ishikawa and colleagues also found other mutations in the Ca antigen site of HA that conferred a more severe disease course, as well as mutations in NA that led to resistance to currently available antiviral drugs.
The rapid emergence of these mutations suggests that “the 2009 pandemic influenza viruses have a genome with an extremely high evolutionary rate,” says Ishikawa. Moreover, “the mutated viruses seemed to rapidly circulate around Japan via modern traffic networks,” he explains. These characteristics of the virus and its spread are important factors to consider when designing future vaccines or when deciding how best to slow any future influenza pandemic outbreaks.
The corresponding author for this highlight is based at the LSA System Development Unit, RIKEN Omics Science CenterReference:
Make way for the mini flying machines
21.03.2018 | American Chemical Society
New 4-D printer could reshape the world we live in
21.03.2018 | American Chemical Society
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
21.03.2018 | Life Sciences
21.03.2018 | Trade Fair News
20.03.2018 | Physics and Astronomy