Studies suggest SARS-CoV-2 likely only infects placental mammals

In a recent study posted on Bio Rxiv* On the preprint server, researchers will perform ontological and taxonomic analyzes of human coronavirus (HCoV) hosts.

study: Taxonomic and ontological analysis of validated natural and laboratory human coronavirus hosts. Image Credit: Stock_Good / Shutterstock.com

Zoonosis and coronavirus

zoonotic disease coronavirus It has had a great impact on mankind. For example, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), which causes acute respiratory distress in humans.

Human coronaviruses can be transmitted between humans and animals. Moreover, these viruses replicate in humans by overcoming the species barrier through migration between natural and potential intermediate hosts.

Human coronaviruses have a variety of laboratory and natural animal hosts, including bats, camels, civet cats, mice, deer, and monkeys. Nevertheless, the exact range of human coronavirus hosts and their infectious relationships remain unclear.

About research

In the present study, researchers investigated common pathogens including SARS-CoV, SARS-CoV-2, Middle East Respiratory Syndrome (MERS)-CoV, and HCoV-229E, HCoV-HKU1, HCoV-OC43, and HCoV-NL63. Four other viruses that cause the common cold.

Multiple resources were consulted to identify animal hosts for confirmed human coronaviruses. By mining and annotating PubMed peer-reviewed articles, natural hosts and animal models, including clinical or data, have been identified as hosts for several human coronaviruses. At least one validation was performed through techniques such as virus isolation, genome sequencing, real-time reverse transcription-polymerase chain reaction (RT-PCR), and antibody neutralization.

Although transgenic mouse models have proven to be a more effective paradigm for studying human coronaviruses, wild-type mice are equally susceptible to SARS-CoV-2 (B.1.351) and MERS-CoV. It is easy to get infected. Therefore, mice were also considered hosts.

To determine the taxonomic classification of human coronaviruses and their host species, the team obtained the hierarchy of different coronaviruses in addition to confirming their laboratory and natural animal hosts from the NCBI taxonomy ontology.

In a hierarchical taxonomy tree, researchers also calculated and extracted the closest ancestors of various species. In addition to many ancestral levels, relationships between different levels of taxonomic terms and specific annotations (such as scientific species names and colloquial names) were also extracted.

A phylogenetic evaluation was performed to determine the evolutionary relationships between different human coronavirus hosts. In particular, angiotensin-converting enzyme-2 (ACE-2) protein sequences from several human coronavirus host species were identified and aligned using the NCBI protein database.

Investigation result

Coronaviruses are positive-stranded ribonucleic acid (RNA) viruses, you didn’t do it order, coronavirus family family, and coronavirus family Subfamily. Four genera comprise the coronavirus subfamily, including alpha, beta, gamma, and delta coronaviruses.

SARS-CoV and SARS-CoV-2 are sarbecovirus subgenus within beta coronavirus Genus.Conversely, MERS-CoV is merbecovirus Within beta coronavirus Genus.

4 coronaviruses that cause colds Orthocoronaviridae Subfamily. HCoV-229E is Duvinacovirus It is a subgenus, and HCoV-NL63 is part of a subgenus. cetracovirus Both are alphacoronaviruses. In addition, HCoV-OC43 and HCoV-HKU1 are subgenus betacoronaviruses. embecovirus.

Taxonomic hierarchy of human coronaviruses based on the NCBITaxon ontology. Dark blue circles show coronaviruses that can infect humans. Under the subgenus Sarbecovirus and the genus Betacoronavirus, SARS-associated coronaviruses are species that include specific strains of SARS-CoV-1 and SARS-CoV-2. Since there are many specific strains of MERS-CoV and SARS-CoV species, only representative strains are shown here. Bat coronavirus RaTG13 (a bat coronavirus strain with high homology to SARS-CoV-2), coronavirus HKU15 (a coronavirus species that infects pigs), and avian coronavirus (a coronavirus species that infects birds) are also non-human viruses. Coronavirus is included here as an example.

In general, alpha and beta coronaviruses infect mammals, including humans, whereas gamma and delta coronaviruses primarily infect birds. In addition, bat-borne betacoronaviruses are closely associated with and responsible for many human respiratory diseases.

There is compelling evidence that cats, tigers, dogs, gorillas, lions, white-tailed deer and pangolins are natural hosts for SARS-CoV-2.

A total of 19 animal models have been utilized in various laboratory studies conducted against human coronaviruses. Human coronaviruses have been isolated from anatomical sites such as saliva, lungs, and blood in these laboratory animals, and some infected animals also develop symptoms.

Primates are phylogenetically closest to humans and thus serve as an effective animal model for human coronaviruses. These Simiiformes laboratory animals, which are under primates, include marmosets, macaques, and African green monkeys.

Conclusion

The results of this study provide the most thorough compilation and classification of wild and hosts of human coronaviruses. This study concentrated on the taxonomic analysis and determination of their common taxonomic classification, and all known human coronavirus hosts are thereal mammals such as marsupials (metateria) and placenta (eutheria). concluded.

*Important Notices

Bio Rxiv We publish a non-peer-reviewed, preliminary scientific report and should not be taken as conclusive, to guide clinical practice/health-related actions, or to be treated as established information.