Since the outbreak of the new crown epidemic, it has not only posed a global threat to public health, but has also placed a heavy burden on the medical system and the global economy
Recently, the China CDC director, Zhong Keyuan pathogenic microorganisms and Key Laboratory of Immunology main Rengao Fu Academy of Sciences , who issued a reminder, in the development of epidemic prevention and control strategies, still need to pay attention to a number of factors
Zhong ASTRI ASTRI academicians They believe that the arms race between the evolution of SARS-CoV-2 and human response strategies will continue for some time
The origin of SARS-CoV-2 remains a mystery
The origin of SARS-CoV-2 remains a mystery The article writes that for the pathogen of any epidemic, tracing the origin of the "primary culprit" is essential to understand its evolution and prevent future epidemics
Previous studies have shown that compared with SARS-CoV-2, the genome of the bat-derived coronavirus RaTG13 is the most similar to SARS-CoV-2 at the whole genome level (96.
The results of multiple studies have shown that SARS-CoV-2 is more likely to come from bats
Two previous studies have shown that in Malay pangolins (SARS-CoV-2 related coronaviruses are found in the body, the RBD region is highly similar
In fact, so far, the way SARS-CoV-2 related coronaviruses are transmitted from bats to humans and whether bats are the original hosts have not yet been solved
It is worth mentioning that on September 30, Gao Fu led an article published in the top medical journal "The Lancet", citing continuous research on the origin of important infectious diseases in the past few decades.
Gao Fu et al.
Gao Fu pointed out that patients with similar symptoms before the pandemic should be reassessed, and samples stored in a wide range of areas should be retested
Virus spillover effect
Virus spillover effect Gao Fu and others wrote in the latest article that in addition to humans, several other mammals have been found to be naturally infected with SARS-CoV-2 through contact with COVID-19 patients, such as cats, dogs, lions, and animals in zoos.
Tiger In addition, in addition to natural infection cases, infection experiments also show that a variety of animals may be susceptible hosts of SARS-CoV-2, such as rabbits, pigs, foxes, and civet cats
Most of the above-mentioned natural infections occur in domestic animals, but far fewer cases have been found in wild animals
Gao Fu et al.
The 41 and 42 amino acids on ACE2 were identified as key sites for SARS-CoV-2 RBD binding
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There are 4 combinations (Y41-Q42, H41-Q42, Y41-E42 and H41-E42) at these two sites.
Among them, the Y41-Q42 combination has the highest binding affinity for SARS-CoV-2 RBD
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In addition, K31 and K353 have been reported to be mutation hotspots that can significantly change the free energy of binding.
Mutations from K353 to A353 may disrupt the binding ability of ACE2 with SARS-CoV-2-RBD
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Host expansion is not over yet
Host expansion is not over yet The article reminds in the last part that the host expansion of the coronavirus has been confirmed
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A previous result showed that if some of the mutations that are adapting to mink are spread back to humans, and even trigger further community transmission, they will pose a huge threat to public health
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Since minks are bred in farms, large-scale slaughter of minks can effectively prevent the spread and accumulation of mutations of the mink source SARS-CoV-2 in the mink population
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However, similar measures cannot be taken for wild animals
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The article points out that when cross-species transmission occurs and spreads in new host populations, adaptive mutations are required.
Therefore, more efforts are needed to investigate the genetic changes of these new varieties of wild white-tailed deer and the corresponding transmission and infectivity to humans.
Influence
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The article particularly pointed out that because SARS-CoV-2 is spreading to wild animals, many other wild animals will also be infected with SARS-CoV-2 through direct or indirect contact with wild white-tailed deer
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Some experimental studies have shown that some animals may be susceptible to SARS-CoV-2, such as Egyptian fruit bats, common marmosets, macaques, bank voles and North American deer rats
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However, these are only the tip of the iceberg, as most land wildlife has not been tested for susceptibility to SARS-CoV-2
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In addition, it is worth noting that there is almost no research on the susceptibility of marine wild animals (especially marine mammals) to SARS-CoV-2
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Due to frequent human marine activities (such as marine aquaculture, marine fishing), the frequency of human contact with marine organisms is relatively high
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If certain marine organisms are highly sensitive to SARS-CoV-2, there is a risk of human transmission to marine organisms
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What's more serious is that SARS-CoV-2 may spread in the marine ecosystem, leading to the production of some new SARS-CoV-2 mutations, posing an unknown threat to humans
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"Therefore, it is necessary to carry out large-scale SARS-CoV-2 screening for terrestrial and marine wildlife, especially susceptible wildlife, to monitor their infections and mutations and formulate further prevention and control strategies
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" Gao Fu et al.
It is believed that this also provides more clues for studying the origin and cross-species spread of SARS-CoV-2
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Focus on the new crown pneumonia epidemic
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