Pangolin or intermediate host! South China Agricultural University: 99% similar to the new coronavirus (source: original)
Xiao Lihua said that most of the early cases of the new coronavirus came from the South China seafood market in Wuhan, while the CDC found the new coronavirus in the environmental samples of the South China seafood market. But there are some other animals in the market besides seafood.
Therefore, the team carried out traceability work around the possible animal sources of coronavirus. Through analysis and sequencing, the team conducted a macrogenomic analysis on more than more than 1000 samples of various wild animals, and identified potential animals. Subsequently, the team carried out molecular biological tests on the samples of these animals, and revealed that the positive rate of u03b2 - coronavirus in pangolin was 70%; at the same time, the team carried out morphological identification of the virus, and analyzed the genome sequence of the virus, proving that pangolin is a potential intermediate host of the new type of coronavirus. We found that there is a u03b2 - coronavirus sequence in pangolin, and then we analyzed its sequence, and found that it is highly similar to the human outbreak virus. We also observed the typical coronavirus morphology, and the naturally infected pangolin also had pathological changes in tissue
Electron micrographs of a new coronavirus isolated from pangolin.
What is the significance of the research results? Xiao Lihua said that the teams findings showed for the first time that pangolin is a potential intermediate host of the new coronavirus; the research results are conducive to blocking the animal source of the virus, avoiding the long-term spread of the pathogen, and may also promote the source control of the new coronavirus.
What is intermediate host? How to lock the pangolin? Are there any other intermediate hosts? The reporter of Nandu interviewed the relevant team members, such as Shen Yongyi, Feng yaoyu, Professor of Guangdong Provincial Laboratory of modern agricultural science and technology of Lingnan and South China Agricultural University.
Shen Yongyi: we are very clear that the source of SARS is bats, but bats can only directly infect people. The research results of this new type of coronavirus prove that the source is bats. This outbreak in Wuhan was in winter, and the possibility of bats infecting people is very small. So there should be a host between them, through the intermediate host to connect bats and people, and build a bridge between them.
Nandu: in the process of traceability, how to determine the pangolin? How did pangolin enter the South China seafood market?
Feng yaoyu: from the perspective of scientific research, we found that the intermediate host does not mean that it comes from the seafood market in South China. We are based on macro genomics analysis in a database on the Internet. Then we found pangolin from the macro genome, which is likely to be highly similar to the virus we found now. Later, when we looked back at the previous samples, we found that they were very similar. Based on this, we did not get the samples from the South China seafood market.
Nandu: is pangolin the only host? Or the possibility of other intermediate hosts?
Shen Yongyi: pangolin is a potential intermediate host. Generally speaking, there are multiple intermediate hosts. Take SARS for example. Besides civet, there are other small animals.
Nandu: since pangolin is the intermediate host, how does it spread to people?
Shen Yongyi: what we need now is to do more work in the later stage to reveal how it was passed on to people.