Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the common cold, while more lethal varieties can cause SARS, MERS and COVID-19, which is causing the ongoing pandemic. In cows and pigs they cause diarrhea, while in mice they cause hepatitis and encephalomyelitis.
Severe acute respiratory syndrome–related coronavirus is a species of virus consisting of many known strains phylogenetically related to severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) that have been shown to possess the capability to infect humans, bats, and certain other mammals. These enveloped, positive-sense single-stranded RNA viruses enter host cells by binding to the angiotensin-converting enzyme 2 (ACE2) receptor. The SARSr-CoV species is a member of the genus Betacoronavirus and of the subgenus Sarbecovirus.
Severe acute respiratory syndrome coronavirus 1 is a strain of coronavirus that causes severe acute respiratory syndrome (SARS), the respiratory illness responsible for the 2002–2004 SARS outbreak. It is an enveloped, positive-sense, single-stranded RNA virus that infects the epithelial cells within the lungs. The virus enters the host cell by binding to angiotensin-converting enzyme 2. It infects humans, bats, and palm civets.
Betacoronavirus is one of four genera of coronaviruses. Member viruses are enveloped, positive-strand RNA viruses that infect mammals. The natural reservoir for betacoronaviruses are bats and rodents. Rodents are the reservoir for the subgenus Embecovirus, while bats are the reservoir for the other subgenera.
Rousettus bat coronavirus HKU9 (HKU9-1) is an enveloped, positive-sense, single-stranded RNA mammalian Group 2 Betacoronavirus discovered in Rousettus bats in China in 2011. This strain of coronavirus is closely related to the EMC/2012 strain found in London which is related to the Middle East respiratory syndrome-related coronavirus (MERS-CoV). The MERS-CoV species is responsible for the 2012 Middle East respiratory syndrome coronavirus outbreak in Saudi Arabia, Jordan, United Arab Emirates, the United Kingdom, France, and Italy.
Bat SARS-like coronavirus WIV1, also sometimes called SARS-like coronavirus WIV1, is a strain of severe acute respiratory syndrome–related coronavirus (SARSr-CoV) isolated from Chinese rufous horseshoe bats in 2013. Like all coronaviruses, virions consist of single-stranded positive-sense RNA enclosed within an envelope.
Shi Zhengli is a Chinese virologist who researches SARS-like coronaviruses of bat origin. Shi directs the Center for Emerging Infectious Diseases at the Wuhan Institute of Virology (WIV). In 2017, Shi and her colleague Cui Jie discovered that the SARS coronavirus likely originated in a population of cave-dwelling horseshoe bats in Xiyang Yi Ethnic Township, Yunnan. She came to prominence in the popular press as "Batwoman" during the COVID-19 pandemic for her work with bat coronaviruses. Shi was included in Time's 100 Most Influential People of 2020.
Coronavirus diseases are caused by viruses in the coronavirus subfamily, a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, the group of viruses cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the common cold, while more lethal varieties can cause SARS, MERS and COVID-19. As of 2021, 45 species are registered as coronaviruses, whilst 11 diseases have been identified, as listed below.
SHC014-CoV is a SARS-like coronavirus (SL-COV) which infects horseshoe bats. It was discovered in Kunming in Yunnan Province, China. It was discovered along with SL-CoV Rs3367, which was the first bat SARS-like coronavirus shown to directly infect a human cell line. The line of Rs3367 that infected human cells was named Bat SARS-like coronavirus WIV1.
The history of coronaviruses is an account of the discovery of the diseases caused by coronaviruses and the diseases they cause. It starts with the first report of a new type of upper-respiratory tract disease among chickens in North Dakota, U.S., in 1931. The causative agent was identified as a virus in 1933. By 1936, the disease and the virus were recognised as unique from other viral disease. They became known as infectious bronchitis virus (IBV), but later officially renamed as Avian coronavirus.
Bat coronavirus RaTG13 is a SARS-like betacoronavirus that infects the horseshoe bat Rhinolophus affinis. It was discovered in 2013 in bat droppings from a mining cave near the town of Tongguan in Mojiang county in Yunnan, China. In February 2020, it was identified as the closest known relative of SARS-CoV-2, the virus that causes COVID-19, sharing 96.1% nucleotide similarity. However, in 2022, scientists found three closer matches in bats found 530 km south, in Feuang, Laos, designated as BANAL-52, BANAL-103 and BANAL-236.
RmYN02 is a bat-derived strain of Severe acute respiratory syndrome–related coronavirus. It was discovered in bat droppings collected between May and October 2019 from sites in Mengla County, Yunnan Province, China. It is the second-closest known relative of SARS-CoV-2, the virus strain that causes COVID-19, sharing 93.3% nucleotide identity at the scale of the complete virus genome. RmYN02 contains an insertion at the S1/S2 cleavage site in the spike protein, similar to SARS-CoV-2, suggesting that such insertion events can occur naturally.
RacCS203 is a bat-derived strain of severe acute respiratory syndrome–related coronavirus collected in acuminate horseshoe bats from sites in Thailand and sequenced by Lin-Fa Wang. It has 91.5% sequence similarity to SARS-CoV-2 and is most related to the RmYN02 strain. Its spike protein is closely related to RmYN02's spike, both highly divergent from SARS-CoV-2's spike.
Rc-o319 is a bat-derived strain of severe acute respiratory syndrome–related coronavirus collected in Little Japanese horseshoe bats from sites in Iwate, Japan. Its has 81% similarity to SARS-CoV-2 and is the earliest strain branch of the SARS-CoV-2 related coronavirus.
Civet SARS-CoV is a coronavirus associated with Severe acute respiratory syndrome coronavirus (SARS-CoV), which infected humans and caused SARS events from 2002 to 2003. It infected the masked palm civet. The severe acute respiratory syndrome coronavirus (SARS-CoV) is highly similar, with a genome sequence similarity of about 99.8%. Because several patients infected at the early stage of the epidemic had contact with fruit-eating Japanese Raccoon Dog in the market, fruit-eating Tanuki may be a direct source of human SARS coronavirus. At the end of 2003, four more people in Guangzhou, China were infected with the disease. Sequence analysis found that the similarity with the Tanuki virus reached 99.9%, and the SARS coronavirus was also caused by cases of Tanuki transmission.
The membrane (M) protein is an integral membrane protein that is the most abundant of the four major structural proteins found in coronaviruses. The M protein organizes the assembly of coronavirus virions through protein-protein interactions with other M protein molecules as well as with the other three structural proteins, the envelope (E), spike (S), and nucleocapsid (N) proteins.
ORF8 is a gene that encodes a viral accessory protein, Betacoronavirus NS8 protein, in coronaviruses of the subgenus Sarbecovirus. It is one of the least well conserved and most variable parts of the genome. In some viruses, a deletion splits the region into two smaller open reading frames, called ORF8a and ORF8b - a feature present in many SARS-CoV viral isolates from later in the SARS epidemic, as well as in some bat coronaviruses. For this reason the full-length gene and its protein are sometimes called ORF8ab. The full-length gene, exemplified in SARS-CoV-2, encodes a protein with an immunoglobulin domain of unknown function, possibly involving interactions with the host immune system. It is similar in structure to the ORF7a protein, suggesting it may have originated through gene duplication.
16BO133 is a SARS-like coronavirus (SL-COV) which was found in the greater horseshoe bat in South Korea. It was published in 2019 and its genome was completely sequenced. The sequenced Korean SARSr-CoV strain belongs to the severe acute respiratory syndrome coronavirus 1, and its genome sequence similarity is 82.8%.
ZC45 and ZXC21, sometimes known as the Zhoushan virus, are two bat-derived strains of severe acute respiratory syndrome–related coronavirus. They were collected from least horseshoe bats by personnel from military laboratories in the Third Military Medical University and the Research Institute for Medicine of Nanjing Command between July 2015 and February 2017 from sites in Zhoushan, Zhejiang, China, and published in 2018. These two virus strains belong to the clade of SARS-CoV-2, the virus strain that causes COVID-19, sharing 88% nucleotide identity at the scale of the complete virus genome.
