atepeq/tico19 huggingface dataset:
Although SARS-CoV and SARS-CoV-2 are very similar due to high nucleotide sequence homology of 82%, they cluster into different branches in the phylogenetic tree.
Nakuba i-SARS-CoV kanye ne-SARS-CoV-2 kucishe kufane kakhulu ngenxa yokwakheka okufanayo kokulandelana kwe-nucleotide okuphakeme okungu-82%, kunamaqembu ahlukene emagatsheni esihlahla se-phylogenetic.
SARS-CoV-2 is apparently less pathogenic but more transmissible compared to SARS-CoV and MERS-CoV.
I-SARS-CoV-2 ibonakala i-pathogenic kancane kodwa ithelelana kakhulu uma iqhathaniswa ne-SARS-CoV kanye ne-MERS-CoV.
Asymptomatic subjects infected with SARS-CoV-2 have been reported and might contribute to its rapid spreading around the world.
Kubikwe ukuthi kunabantu abangenazo izimpawu abaphethwe i-SARS-CoV-2 futhi bangase babe nomthelela wokubhebhetheka kwayo ngokushesha emhlabeni wonke.
Comparing and contrasting SARS-CoV-2 with the other six HCoVs reveal similarities and differences of great interest.
Ukuqhathanisa nokuhlukanisa i-SARS-CoV-2 namanye ama-HCoV ayisithupha kuveza ukufana nokuhluka okuthakazelisa kakhulu.
First, the incubation period and the duration of the course of HCoV disease are very similar.
Okokuqala, inkathi yokufukanyelwa kanye nobude besikhathi sokuqhubeka kwesifo se-HCoV kufana kakhulu.
In this regard, SARS-CoV-2 follows the general trend of the other six HCoVs.
Ngokuqondene nalokhu, i-SARS-CoV-2 ilandela ithrendi evamile yamanye ama-HCoV ayisithupha.
Second, the severity of symptoms of COVID-19 lies between SARS-CoV and the four community-acquired HCoVs (i.e. HCoV-229E, HCoV-OC43, HCoV-HKU1 and HCoV-NL63).
Okwesibili, ubucayi bezimpawu ze-COVID-19 buphakathi kwe-SARS-CoV kanye nama-HCoV amane atholwa emphakathini (okungukuthi i-HCoV-229E, i-HCoV-OC43, i-HCoV-HKU1 kanye ne-HCoV-NL63).
On one hand, SARS-CoV-2 infection exhibits features that are more commonly seen during infection with community-acquired HCoVs, including the presentation of non-specific, mild or even no symptoms.
Ngakolunye uhlangothi, isifo se-SARS-CoV-2 sibonisa izici ezivame ukubonwa phakathi nokutheleleka ngama-HCoV atholwa emphakathini, okubandakanya ukungabikhona kwezimpawu ezicacile, izimpawu ezincane noma ukungabikhona kwezimpawu.
On the other hand, a small subset of severe cases of COVID-19 can also be seen as in the case of SARS-CoV infection, although the ratio is a bit lower.
Ngakolunye uhlangothi, isethi engaphansi encane yezimo ezibucayi ze-COVID-19 ingabonwa futhi njengasesimweni sesifo se-SARS-CoV, nakuba isilinganiso siphansi kancane.
Third, the transmission of SARS-CoV-2 also shows interesting patterns characteristic of both community-acquired HCoVs and SARS-CoV.
Okwesithathu, ukuthelelana kwe-SARS-CoV-2 kuphinde kubonise amaphethini athakazelisayo anesici sawo womabili ama-HCoV atholakala emphakathini kanye ne-SARS-CoV.
On one hand, the transmissibility of SARS-CoV-2 is at least as high as that of community-acquired HCoVs.
Ngakolunye uhlangothi, ukudluliswa kwe-SARS-CoV-2 kuphakeme njengokwama-HCoV atholwe emphakathini.
On the other hand, it remains to be verified whether the transmissibility of SARS-CoV-2 decreases after passages in humans as in the cases of SARS-CoV and MERS-CoV.
Ngakolunye uhlangothi, kusazoqinisekiswa ukuthi ukudluliselwa kwe-SARS-CoV-2 kuyancipha yini kubantu njengasesimweni se-SARS-CoV ne-MERS-CoV.
Finally, same as the other HCoVs, SARS-CoV-2 can be detected in fecal samples.
Okokugcina, ngokufana namanye ama-HCoV, i-SARS-CoV-2 ingatholwa kumasampula endle.
Whether fecal-oral transmission of SARS-CoV-2 plays an important role as in the case of SARS-CoV at least under some circumstance remains to be clarified by future studies.
Ukuthi ukudluliswa ngendle-ngomlomo kwe-SARS-CoV-2 kudlala indima ebalulekile yini uma kuziwa ku-SARS-CoV ngaphansi kwezimo ezithile kusazocaciswa izingcwaningo zesikhathi esizayo.
It is also of particularly great interest to see whether SARS-CoV-2 might exhibit seasonality as in the cases of community-acquired HCoVs.
Kuphinde kuthakazelise kakhulu ukubona ukuthi ingabe i-SARS-CoV-2 izobonisa ukuvela ngezinkathi ezithile zonyaka njengoba kunjalo ngama-HCoV atholakala emphakathini.
Nevertheless, the features of SARS-CoV-2 including its transmissibility, pathogenicity and sustainable spreading after passages in humans will be influential on the ultimate fate of the ongoing outbreak of COVID-19.
Noma kunjalo, izici ze-SARS-CoV-2 okubandakanya ukutheleleka kwayo, i-pathogenicity nokubhebhetheka okulondolozekayo ngemva kokudlulela kubantu kuzoba nethonya esiphethweni sokugcina sokubheduka okuqhubekayo kwe-COVID-19.
All four community-acquired HCoVs causing mild symptoms have been well adapted to humans.
Wonke ama-HCoV atholwa emphakathini abangela izimpawu ezincane azivumelanise kahle nabantu.
From another perspective, it might also be true that humans have been well adapted to these four HCoVs.
Ngokomunye umbono, kungase futhi kube yiqiniso ukuthi abantu bazivumelanise kahle nalawa ma-HCoV amane.
In other words, both could be the survivors of ancient HCoV pandemics.
Ngamanye amazwi, kokubili kungenzeka ukuthi kwasinda kubhubhane lwe-HCoV yasendulo.
HCoVs that cause severe diseases in humans and humans who developed severe HCoV diseases have been eliminated.
Ama-HCoV abangela izifo ezibucayi kubantu futhi abantu abaphathwa izifo ze-HCoV ebucayi abasekho.
For this to happen, HCoVs have to replicate in humans to sufficient extent to allow the accumulation of adaptive mutations that counteract host restriction factors.
Ukuze kwenzeke lokhu, ama-HCoV kufanele aphindeke kubantu ngokwezinga elanele ukuze kuvunyelwe ukukhula koshintsho oluvumelana nezimo okuphikisana nezici zokukhawulwa kombungazi.
In this sense, the longer the SARS-CoV-2 outbreak persists and the more people that it infects, the greater chance that it will fully adapt to humans.
Ngale ndlela, uma ukubheduka kwe-SARS-CoV-2 kuphikelela futhi ithelela abantu abaningi, kuzoba nethuba elikhulu lokuthi izozivumelanisa kakhulu nabantu.
If it adapts well, its transmission in humans would be difficult to stop by quarantine or other infection control measures.
Uma izivumelanisa kahle kakhulu, ukuthelela kwayo abantu kungabanzima ukukuvimba ngokuzivalela noma ezinye izindlela zokulawula ukutheleleka.
For many years, the four community-acquired CoVs circulate in human populations, triggering common cold in immunocompetent subjects.
Sekuyiminyaka eminingi, ama-CoV amane atholwa emphakathini ejikeleza emphakathini wabantu, okubangela umkhuhlane ovamile kubantu abanokusabela okufanele kwamasosha omzimba.
These viruses do not need an animal reservoir.
Lawa magciwane awadingi umthombo oyisilwane.
In contrast, highly pathogenic SARS-CoV and MERS-CoV have not adapted to humans well and their transmission within humans cannot be sustained.
Ngokuphambene nalokho, i-SARS-CoV kanye ne-MERS-CoV e-pathogenic kakhulu awakazivumelanisi kahle nabantu futhi ukuthelelana kwawo ngaphakathi kwabantu akukwazi ukulondolozwa.
They need to maintain and propagate in their zoonotic reservoirs and seek the chance to spillover to susceptible human targets, possibly via one or more intermediate and amplifying hosts.
Adinga ukuzigcina asesimweni futhi akhule kumthombo wawo we-zoonotic futhi afuna ithuba lokudlulela kuzisulu ezingachayeka, cishe ngombungazi omaphakathi oyedwa noma ngaphezulu futhi kukhuliswe ababungazi.
SARS-CoV-2 has features that are similar to both SARS-CoV/MERS-CoV and the four community-acquired HCoVs.
I-SARS-CoV-2 inezici ezifana nakho kokubili i-SARS-CoV/MERS-CoV kanye nama-HCoV amane atholwa emphakathini.
It is highly transmissible like community-acquired HCoVs, at least for the time being.
Itheleleka kakhulu njengama-HCoV atholwa emphakathini, okungenani kusidalwa sokuqala.
However, it is more pathogenic than community-acquired HCoVs and less pathogenic than SARS-CoV or MERS-CoV.
Nokho, i-pathogenic kakhulu kunama-HCoV atholwa emphakathini futhi ine-pathogenic encane ku-SARS-CoV noma i-MERS-CoV.
It remains to be seen whether it will adapt fully to humans and circulate within humans without a reservoir or intermediate animal host.
Kusazobonwa ukuthi izozivumelanisa ngokugcwele yini nabantu futhi ijikeleze ngaphandle komthombo noma umbungazi wesilwane omaphakathi.
Before discussing the animal origins of HCoVs, it will serve us well to discuss the definitions and characteristics of evolutionary, natural, reservoir, intermediate and amplifying hosts of HCoVs.
Ngaphambi kokuthi kuxoxwe ngemisuka eyizilwane yama-HCoV, kuzosiza ukuthi sixoxe ngezincazelo nezici zababungazi boshintsho, abangokwemvelo, abawumthombo, abamaphakathi nabokukhulisa ama-HCoV.
An animal serves as the evolutionary host of an HCoV if it harbours a closely related ancestor sharing high homology at the level of nucleotide sequence.
Isilwane siba umbungazi woshintsho we-HCoV uma sifukamele ukhokho ohlobene ngokuseduze okwabelwana naye nge-homology ephakeme ezingeni lokulandelana kwe-nucleotide.
The ancestral virus is usually well adapted and non-pathogenic in this host.
Igciwane eliwukhokho livame ukuzivumelanisa kahle futhi alikubangeli ukugula kulo mbungazi.
Likewise, a reservoir host harbours HCoV continuously and for long term.
Ngokufanayo, umbungazi owumthombo ufukamela i-HCoV ngokuqhubekayo futhi isikhathi eside.
In both cases, the hosts are naturally infected and are the natural hosts of HCoV or its parental virus.
Kuzo zombili izimo, ababungazi batheleleka ngokwemvelo futhi bangababungazi abangokwemvelo be-HCoV noma igciwane layo elingumzali.
In contrast, if the HCoV is newly introduced to an intermediate host right before or around its introduction to humans, it is not well adapted to the new host and is often pathogenic.
Ngokuphambene nalokho, uma i-HCoV yethulwa kabusha kumbungazi omaphakathi ngaphambili noma ngasekwethulweni kubantu, ayizivumelanisile kahle nombungazi omusha futhi ngokuvamile ibangela ukugula.
This intermediate host can serve as the zoonotic source of human infection and play the role of an amplifying host by allowing the virus to replicate transiently and then transmitting it to humans to amplify the scale of human infection.
Lo mbungazi omaphakathi angase abe umthombo oyi-zoonotic yokutheleleka kwabantu futhi adlale indima yokukhulisa umbungazi okuvumela igciwane ukuthi liphindeke isikhashana futhi lidluliselwe kubantu ukuze kukhuliswe izinga lokutheleleka kwabantu.
An HCoV can undergo a dead-end infection if it cannot sustain its transmission within the intermediate host.
I-HCoV ingabhekana nokutheleleka kokugcina uma ingakwazi ukulondoloza ukutheleleka kwayo ngaphakathi kombungazi omaphakathi.
On the contrary, HCoVs can also adapt to the intermediate host and even establish long-term endemicity.
Ngokuphambene nalokho, ama-HCoV ayakwazi ukuzivumelanisa nombungazi omaphakathi futhi aze asungule ne-endemicity yesikhathi eside.
In this case, the intermediate host becomes a natural reservoir host.
Kulesi simo, umbungazi omaphakathi uba umbungazi owumthombo ongokwemvelo.
Epidemiological data revealed retrospectively that the index case of SARS had a contact history with game animals.
Idatha ye-epidemiological yabonisa ukuthi lapho kubhekwa emuva ukuthi isiguli esiyinkomba ye-SARS sasinomlando wokuxhumana nezilwane ezizingelwayo.
Subsequent seroprevalence investigations indicated that animal traders had a higher prevalence of anti-SARS-CoV IgG compared with that of the general population.
Izingcwaningo ze-seroprevalence ezalandela zabonisa ukuthi abahwebi bezilwane babe ne-IgG emelene SARS-CoV ephakeme uma beqhathaniswa nesibalo sabantu abavamile.
Masked palm civets (Paguma larvata) and a racoon dog in live animal markets were first identified to carry SARS-CoV-like viruses that are almost identical to SARS-CoV.
Ama-masked palm civet (i-paguma larvata) kanye nenja ye-racoon ezimakethe zezilwane eziphilayo kwatholwa ukuthi athwala amagciwane afana nawe-SARS-CoV acishe afane ne-SARS-CoV.
This was indirectly supported by the fact that no further SARS was reported after killing all civets in the markets.
Lokhu kwasekelwa ngokungaqondile iqiniso lokuthi ayikho i-SARS eyengeziwe eyabikwa ngemva kokubulawa kwawo wonke ama-civet ezimakethe.
However, it has been reported that masked palm civets from the wild or farms without exposure to the live animal markets were largely negative for SARS-CoV, suggesting that masked palm civets might only serve as the intermediate amplifying host but not the natural reservoir of SARS-CoV.
Nokho, kuye kwabikwa ukuthi ama-masked palm civet asendle noma emapulazini angakaze achayeke ezimakethe zezilwane eziphilayo ayenegethivu uma kuziwa ku-SARS-CoV, okusikisela ukuthi ama-masked palm civet angase abe umbungazi wokukhulisa omaphakathi kodwa hhayi umthombo ongokwemvelo we-SARS-CoV.
Notably, since 80% of the different animals in the markets in Guangzhou have anti-SARS-CoV antibodies, the possibilities that multiple species of small mammals might also serve as intermediate amplifying hosts of SARS-CoV cannot be excluded.
Kuyaphawuleka, ukuthi u-80% wezilwane ezihlukahlukene ezimakethe zase-Guangzhou zinezivikeli-mzimba ezimelene ne-SARS-CoV, asikwazi ukushalazela ithuba lokuthi izilwane eziningi ezincelisayo zingababungazi abakhulisayo abamaphakathi be-SARS-CoV.
All of these appear to be dead-end hosts of SARS-CoV.
Zonke lezi zibonakala zingababungazi bokugcina be-SARS-CoV.
Subsequent search for the natural animal host of SARS-CoV unveiled a closely related bat CoV, termed SARS-related Rhinolophus bat CoV HKU3 (SARSr-Rh-BatCoV HKU3), which exists in Chinese horseshoe bats.
Ucwaningo olwalandela lombungazi oyisilwane esingokwemvelo se-SARS-CoV lwaveza i-CoV ehlobene ngokuseduze nelulwane, ebizwa ngokuthi i-SARS-related Rhinolophus bat CoV HKU3 (SARSr-Rh-BatCoV HKU3), etholakala kumalulwane abizwa ngesicathulo sehhashi ase-Chine.
These bats are positive for anti-SARS-CoV antibodies and genome sequence of SARSr-Rh-BatCoV HKU3.
Lawa malulwane aphozithivu uma kuziwa kuzivikeli-mzimba ezimelene ne-SARS-CoV kanye nokulandelana kwezakhi zofuzo ze-SARSr-Rh-BatCoV HKU3.
This and other bat CoVs share 88-92% nucleotide sequence homology with SARS-CoV.
Le kanye namanye ama-CoV elulwane abelana ngo-88-92% we-homology yokulandelana kwe-nucleotide ne-SARS-CoV.
These studies have laid the foundation for the new concept that bats host emerging human pathogens.
Lezi zingcwaningo ziholele ekusungulweni kombono omusha wokuthi amalulwane abungaza ama-pathogen amasha abantu.
Several SARS-like CoVs (SL-CoVs) have also been identified from bats, but none except for one designated WIV1 can be isolated as live virus.
Ama-CoV afana ne-SARS (ama-SL-CoV) aphawulwe kumalulwane, kodwa awekho ngaphandle kwaleyo ebizwa ngokuthi i-WIV1 akwazi ukuhlukaniswa njengegciwane eliphilayo.
Human angiotensin converting enzyme 2 (ACE2) is known to be the receptor of SARS-CoV.
I-angiotensin converting enzyme 2 (I-ACE2) yabantu yaziwa njengesisabeli se-SARS-CoV.
WIV1 derived from fecal sample of bats was demonstrated to use bat, civet and human ACE2 as receptor for cell entry.
I-WIV1 ethathwe kusampula lendle yamalulwane kwaboniswa ukuthi isebenzisa ilulwane, i-civet kanye ne-ACE2 yabantu njengesisabeli sokungena kuseli.
Intriguingly, sera of convalescent SARS patients were capable of neutralizing WIV1.
Ngokuthakazelisayo, i-sera yeziguli ezilulame ku-SARS yayikwazi ukubulala i-WIV1.
Thus far, WIV1 represents the most closely related ancestor of SARS-CoV in bats, sharing 95% nucleotide sequence homology.
Kuze kube manje, i-WIV1 imelele ukhokho ohlobene ngokuseduze we-SARS-CoV kumalulwane, yabelana ngo-95% we-homology yokulandelana kwe-nucleotide.
Albeit the high homology between these two viruses, it is generally believed that WIV1 is not the immediate parental virus of SARS-CoV and bats are not the immediate reservoir host of SARS-CoV.
Nakuba kune-homology ephakeme phakathi kwalawa magciwane amabili, kukholelwa ngokuvamile ukuthi i-WIV1 ayilona igciwane elingumzali oseduze we-SARS-CoV futhi amalulwane awayena umbungazi oseduze we-SARS-CoV.
Phylogenetic analysis clusters MERS-CoV to the same group as bat CoV-HKU4 and bat CoV-HKU5.
Ukuhlaziywa kwe-phylogenetic kuhlanganisa i-MERS-CoV neqembu elifanayo nelulwane le-CoV-HKU4 kanye nelulwane le-CoV-HKU5.
Bat CoV-HKU4 and MERS-CoV utilize the same host receptor, dipeptidyl peptidase 4 (DPP4), for virus entry.
I-CoV-HKU4 yelulwane kanye ne-MERS-CoV kusebenzisa isisabeli sombungazi esifanayo, i-dipeptidyl peptidase 4 (DPP4), ekungeneni kwegciwane.
RNA-dependent RNA polymerase sequences of MERS-CoV are phylogenetically closer to counterparts in bat beta-CoVs identified from Europe and Africa.
Ukulandelana kwe-polymerase ye-RNA ethembele ku-RNA ye-MERS-CoV isondelene ngoku-phylogenetically kozakwabo bama-beta-CoV elulwane atholwe e-Europe nase-Africa.
Up to now, no live MERS-CoV can be found in wild bats.
Kuze kube manje, ayikho i-MERS-CoV ephilayo etholakala kumalulwane asendle.
MERS-CoV and its closest relative bat CoV-HKU25 share only 87% nucleotide sequence homology.
I-MERS-CoV kanye nesihlobo sayo esiseduze i-CoV-HKU25 yelulwane kwabelana kuphela ngo-87% we-homology yokulandelana kwe-nucleotide.
Thus, bats might not be the immediate reservoir host of MERS-CoV.
Ngenxa yalokho, amalulwane angase angabi umbungazi owumthombo oseduze we-MERS-CoV.
On the other hand, studies in Middle East have shown that dromedary camels are seropositive for MERS-CoV-specific neutralizing antibodies, same as camels of Middle East origin in multiple African countries.
Ngakolunye uhlangothi, izingcwaningo e-Middle East ziye zabonisa ukuthi amakamela e-dromedary a-seropositive kuzivikeli-mzimba ezibulala i-MERS-CoV ngokuqondile, ngokufana namakamela adabuka e-Middle East emazweni amaningi ase-Afrika.
Live MERS-CoV identical to the virus found in humans was isolated from the nasal swabs of dromedary camels, further indicating that camels serve as the bona fide reservoir host of MERS-CoV.
I-MERS-CoV ephilayo efana negciwane elitholwe kubantu yahlukaniswa kuswabhu yasekhaleni yamakamela e-dromedary, okwabonisa ngokuqhubekayo ukuthi amakamela angumbungazi ongumthombo wangempela we-MERS-CoV.
It is also noteworthy that generally mild symptoms but massive virus shedding were observed in camels experimentally infected with MERS-CoV.
Kuyaphawuleka futhi ukuthi ngokuvamile kwabonwa izimpawu ezincane kodwa ukukhishwa okukhulu kwegciwane kumakamela athelelekile nge-MERS-CoV ngokocwaningo.
Notably, infected camels shed viruses not only through respiratory route but also through fecal-oral route, which is also the main route for virus shedding from bats.
Kuyaphawuleka, ukuthi amakamela athelelekile awagcinanga ukukhipha amagciwane ngomgudu wokuphefumula kuphela kodwa futhi nangomgudu wendle-womlomo, okuphinde kube umzila oyinhloko wokukhishwa kwegciwane elivela kumalulwane.
However, questions still remain since many confirmed cases of MERS have no contact history with camels prior to symptom onset, plausibly ascribed to human-to-human transmission or unknown transmission routes involving unrecognized animal species that harbour MERS-CoV.
Nokho, imibuzo isasele njengoba ukugula okuningi kwe-MERS kungenawo umlando wokuxhumana namakamela ngaphambi kokuqala kwezimpawu, kungenzeka ukuthi ukuthelelana okusuka kumuntu kuye komunye noma imizila yokuthelelana engaziwa ehilela izilwane ezingaziwa ezifukamela i-MERS-CoV.
SARS-CoV-2 shares 96.2% nucleotide homology with a bat CoV RaTG13 isolated from Rhinolophus affinis bats.
I-SARS-CoV-2 yabelana nge-homology ye-nucleotide engu-96.2% ne-CoV RaTG13 yelulwane ehlukaniswe kumalulwane e-Rhinolophus affinis.
As in the cases of SARS-CoV and MERS-CoV, the sequence divergence between SARS-CoV-2 and RaTG13 is too great to assign parental relationship.
Njengoba kunjalo nge-SARS-CoV kanye ne-MERS-CoV, ukuhlukahluka kokulandelana phakathi kwe-SARS-CoV-2 kanye ne-RaTG13 kukhulu kakhulu ukuthi kungabelwa ubudlelwano bomzali.
That is to say, bats might not be the immediate reservoir host(s) of SARS-CoV-2 unless almost identical bat CoVs are found in future.
Lokho kusho ukuthi, amalulwane kungenzeka ukuthi awayena umbungazi owumthombo oseduze we-SARS-CoV-2 ngaphandle kwalapho kutholwa ama-CoV elulwane acishe afane esikhathini esizayo.
Presumably, the intermediate animal hosts of SARS-CoV-2 should be among the wildlife species sold and killed at the Huanan Seafood Wholesale Market, with which many of the initial cases of COVID-19 were associated, indicative of a probable animal-to-human transmission event.
Kucatshangelwa ukuthi, ababungazi besilwane esimaphakathi se-SARS-CoV-2 kufanele babe phakathi kwezilwane zasendle ezidayiswa futhi zibulawe e-Huanan Seafood Wholesale Market, iningi lazo lalihlobene nokugula kokuqala kwe-COVID-19, okubonisa ukuthi kungenzeka ukuthi kwaba nesenzakalo sokuthelelana okusuka kuzilwane kuye kubantu.
Several recent studies based on metagenomic sequencing have suggested that a group of endangered small mammals known as pangolins (Manis javanica) could also harbour ancestral beta-CoVs related to SARS-CoV-2.
Izingcwaningo zakamuva ezimbalwa ezisekelwe ekulandelaneni kwe-metagenomic ziye zasikisela ukuthi iqembu lezilwane ezincane ezincelisayo ezaziwa ngokuthi ama-pangolin (i-Manis javanica) kungenzeka ukuthi zifukamele ama-beta-CoV amadala ahlobene ne-SARS-CoV-2.
These novel pangolin CoV genomes share 85-92% nucleotide sequence homology with SARS-CoV-2.
Lawa ma-genome amasha e-pangolin CoV abelana ngo-85-92% we-homology yokulandelana kwe-nucleotide ne-SARS-CoV-2.
However, they are equally closely related to RaTG13 with about 90% identity at the level of nucleotide sequence.
Nokho, ahlobene ngokuseduze ngokulinganayo ne-RaTG13 ngomazisi ocishe ube ngu-90% ezingeni lokulandelana kwe-nucleotide.
They cluster into two sub-lineages of SARS-CoV-2-like viruses in the phylogenetic tree, one of which share a more similar receptor binding domain (RBD) with SARS-CoV-2, with 97.4% amino acid sequence identity.
Ahlangana abe yizinhlu ezingaphansi ezimbili zamagciwane acishe afane ne-SARS-CoV-2 esihlahleni esi-phylogenetic, esinye sazo sabelana ngesizinda sokunamathisela sesisabeli esifana kakhulu (i-RBD) ne-SARS-CoV-2, nokufana kokulandelana kwe-amino acid okungu-97.4%.
In stark contrast, the RBDs of SARS-CoV-2 and RaTG13 are more divergent, albeit a higher degree of sequence homology genome-wide.
Ngokungafani okukhulu, ama-RBD e-SARS-CoV-2 ne-RaTG13 ahlukene kakhulu, nakuba kunezinga eliphakeme le-genome ebanzi yokulandelana kwe-homology.
An earlier study on diseased pangolins also reported the detection of viral contigs from lung samples, which turn out to be similarly related to SARS-CoV-2.
Ucwaningo lwangaphambilini lwama-pangolin agulayo lwabika ukutholwa kwama-contig egciwane kumasampula amaphaphu, okubonakala ehlobene ngokufanayo ne-SARS-CoV-2.
This study adopted different assembly methods and manual curation to generate a partial genome sequence comprising about 86.3% of the full-length viral genome.
Lolu cwaningo lwasebenzisa izindlela zokwakhiwa ezihlukahlukene kanye nokuhlelwa okwenziwa ngesandla ukuze kwakhiwe ukulandelana kwe-genome eyingxenye eyakhiwa cishe u-86.3% wobude obuphelele be-genome yegciwane.
We cannot exclude the possibility that pangolin is one of the intermediate animal hosts of SARS-CoV-2.
Asikwazi ukubekela eceleni ithuba lokuthi i-pangolin ingesinye sezilwane ezingababungazi abaseduze be-SARS-CoV-2.
However, currently there is no evidence in support of a direct pangolin origin of SARS-CoV-2 due to the sequence divergence between SARS-CoV-2 and pangolin SARS-CoV-2-related beta-CoVs.
Nokho, okwamanje abukho ubufakazi obusekela ukuthi i-pangolin ingumsuka oqondile we-SARS-CoV-2 ngenxa yokuhlukahluka kokulandelana phakathi kwe-SARS-CoV-2 kanye ne-SARS-CoV-2 ye-pangolin ehlobene nama-beta-CoV.
In addition, the distance between SARS-CoV-2 and RaTG13 is even shorter than that between SARS-CoV-2 and pangolin SARS-CoV-2-related beta-CoVs.
Ngaphezu kwalokho, ibanga eliphakathi kwe-SARS-CoV-2 kanye ne-RaTG13 lifushane nakakhulu phakathi kwe-SARS-CoV-2 kanye ne-SARS-CoV-2 ye-pangolini ehlobene nama-beta-CoV.
The evolutionary pathway of SARS-CoV-2 in bats, pangolins and other mammals remains to be established.
Umgudu wokuziphendukela we-SARS-CoV-2 kumalulwane, ama-pangolin nezinye izilwane ezincelisayo usazotholwa.
Whereas the highest sequence homology has been found in the RBDs between SARS-CoV-2 and pangolin, SARS-CoV-2-related beta-CoVs, SARS-CoV-2 and RaTG13 share the highest genome-wide sequence homology.
Nakuba i-homology yokulandelana okuphakeme itholiwe kuma-RBD phakathi kwe-SARS-CoV-2 ne-pangolin, i-SARS-CoV-2 ehlobene nama-beta-CoV, i-SARS-CoV-2 ne-RaTG13 kwabelana nge-homology ephakeme yokulandelana kwe-genome ebanzi.
It is highly speculative that the high degree of similarity between the RBDs of pangolin SARS-CoV-2-related beta-CoVs and SARS-CoV-2 is driven by selectivity-mediated convergent evolution.
Kunezinsolo eziphakeme zokuthi izinga eliphakeme lokufana phakathi kwama-RBD e-SARS-CoV-2 ye-pangolini ehlobene nama-beta-CoV kanye ne-SARS-CoV-2 kuqhutshwa ukuziphendukela kokuhlangana okuxhumana ngokukhethwa.
A counter-proposal is in favour of a recombination between a pangolin SARS-CoV-2-related beta-CoV and RaTG13 in the third wild animal species.
Esinye isiphakamiso sincoma ukuhlanganiswa kabusha okuphakathi kwe-SARS-CoV-2 ye-pangolini ehlobene ne-beta-CoV kanye ne-RaTG13 kusilwane sesithathu sasendle.
As a driving force in evolution, recombination is widespread among beta-CoVs.
Njengamandla aqhuba ukuziphendukela, ukuhlanganiswa kabusha kusakazekile phakathi kwama-beta-CoV.
The jury is still out on the immediate zoonotic origin of SARS-CoV-2.
Isiphetho asikafinyelelwa ngokuqondene nomsuka we-zoonotic eseduze ye-SARS-CoV-2.
Besides the highly pathogenic HCoVs, the zoonotic origin of HCoV-229E, HCoV-OC43, HCoV-NL63 and HCoV-HKU1 have also been studied.
Ngaphandle kwama-HCoV a-pathogenic kakhulu, umsuka we-zoonotic ye-HCoV-229E, i-HCoV-OC43, i-HCoV-NL63 kanye ne-HCoV-HKU1 nawo ucwaningiwe.
Phylogenetic evidence indicated that both HCoV-NL63 and HCoV-229E might have originated from bat CoVs, while the parental viruses of HCoV-OC43 and HCoV-HKU1 have been found in rodents.
Ubufakazi be-phylogenetic bubonise ukuthi kokubili i-HCoV-NL63 kanye ne-HCoV-229E kungenzeka ukuthi kwaqala kuma-CoV elulwane, kuyilapho amagciwane angumzali e-HCoV-OC43 kanye ne-HCoV-HKU1 etholwe kumagundane.
It has been reported that a bat CoV termed ARCoV.2 (Appalachian Ridge CoV) detected in North American tricolored bat displayed close relationship with HCoV-NL63.
Kubikwe ukuthi i-CoV yelulwane ebizwa ngokuthi i-ARCoV.2 (i-Appalachian Ridge CoV) etholwe elulwaneni elinemibala emithathu laseNyakatho Melika yabonisa ubudlelwano obuseduze ne-HCoV-NL63.
On the other hand, HCoV-229E was genetically related to another bat CoV, termed Hipposideros/GhanaKwam/19/2008, which was detected in Ghana, while camelids have also been suspected as its intermediate host.
Ngakolunye uhlangothi, i-HCoV-229E yayihlobene ngokwezakhi zofuzo nenye i-CoV yelulwane, ebizwa ngokuthi i-Hipposideros/GhanaKwam/19/2008, eyatholwa e-Ghana, kuyilapho ama-camelid aye asolwa ngokuba umbungazi wayo oseduze.
For clarity, the current knowledge on animal origins of known HCoVs is summarized in Figure ​1 and Table 2.
Ukuze sicacise, ulwazi lwamanje oluphathelene nemisuka eyizilwane yama-HCoV aziwayo lufinyezwe Kumfanekiso ​1 kanye Nethebula 2.
Phylogenetic analysis has provided evidence for interspecies transmission events of HCoVs in the history.
Ukuhlaziywa kwe-phylogenetic kunikeze ubufakazi bezigameko zokuthelelana kwezidalwa zama-HCoV emlandweni.
When HCoV-OC43 crossed species to infect humans from domestic livestock around 1890, a pandemic of respiratory infection was recorded.
Ngenkathi i-HCoV-OC43 isuka kwesinye isilwane ukuze idluliselwe kubantu yasuka ezilwaneni ezifuywayo cishe ngo-1890, kwaqoshwa ubhubhane lwesifo sokuphefumula .
The interspecies transmission history of HCoV-229E is less clear.
Umlando wokuthelelana kwezidalwa ezihlukahlukene we-HCoV-229E awucacile kakhulu.
Bat alpha-CoVs closely related to HCoV-229E have been found.
Kutholwe ama-alpha-CoV elulwane ahlobenene-HCoV-229E.
Between them there is an alpaca alpha-CoV.
Phakathi kwawo kukhona i-alpha-CoV ye-alpaca.
Several lines of evidence support the transmission of virus from bats to humans directly.
Ubufakazi obumbalwa busekela ukudluliswa kwegciwane lisuka emalulwaneni liye kubantu ngokuqondile.
First, humans but not alpacas might have contact with bats in a shared ecological niche.
Okokuqala, abantu hhayi ama-alpaca kungenzeka ukuthi baxhumane namalulwane endaweni ezungezile efanayo.
Instead, humans have close contact with alpacas.
Kunalokho, abantu abasondelana ngokuseduze nama-alpaca.
Second, HCoV-229E-related bat alpha-CoVs are diverse and non-pathogenic in bats, whereas alpaca alpha-CoV caused an outbreak of respiratory disease in infected animals.
Okwesibili, ama-alpha-CoV elulwane ahlobene ne-HCoV-229E ahlukahlukene futhi awakubangeli ukugula kumalulwane, kuyilapho i-alpha-CoV ye-alpaca yabangela ukubheduka kwesifo sokuphefumula kuzilwane ezithelelekile.
Finally, alpaca alpha-CoV has not been found in feral animals.
Okugcina, i-alpha-CoV ye-alpaca ayikatholwa kuzilwane zasendle.
Thus, the possibility cannot be excluded that alpacas obtain the HCoV-229E-related alpha-CoV from humans.
Ngenxa yalokho, ngeke silishalazele ithuba lokuthi ama-alpaca athola i-alpha-CoV ehlobene ne-HCoV-229E kubantu.
In fact, bats are the direct source of human pathogenic viruses including rabies virus, Ebola virus, Nipah virus and Hendra virus.
Eqinisweni, amalulwane awumthombo oqondile wamagciwane abangela ukugula kwabantu okuhlanganisa igciwane lamarabi, igciwane le-Ebola, igciwane le-Nipah kanye negciwane le-Hendra.
It is therefore not too surprising that bats might transmit HCoV-229E to humans directly.
Ngakho akumangalisi ukuthi amalulwane kungenzeka adlulisele i-HCoV-229E kubantu ngokuqondile.
Alternatively, whereas bat alpha-CoVs serve as the gene pool of HCoV-229E, alpacas and dromedary camels might serve as intermediate hosts that transmit viruses to humans, exactly as in the case of MERS-CoV.
Ngakolunye uhlangothi, lapho ama-alpha-CoV elulwane esebenza njengeqoqo lezakhi zofuzo ze-HCoV-229E, ama-alpaca kanye namakamela e-dromedary kungenzeka ukuthi angumbungazi omaphakathi odlulisela igciwane kubantu, njengoba kunjalo nge-MERS-CoV.
MERS-CoV serves as an excellent example of interspecies transmission from bats to dromedary camels and from dromedary camels to humans.
I-MERS-CoV iyisibonelo esihle sokuthelelana kwezidalwa ezingafani kusukela kumalulwane kuye kumakamela e-dromedary kuye kubantu.
The evolutionary origin of MERS-CoV from bats is known at its initial identification and has also been strengthened by subsequent findings.
Umsuka wokuziphendukela kwe-MERS-CoV evela kumalulwane uyaziwa ekuhlonzweni kwayo kokuqala futhi uqiniswe ngokutholiwe okulandelayo.
It is obvious that bats provide a rich pool of virus species for interspecies exchange of genetic fragments and interspecies transmission.
Kusobala ukuthi amalulwane anikeza izinhlobonhlobo zamagciwane ithuba lokuthi kube nokushintshana kwezingxenye zezakhi zofuzo phakathi kwezilwane ezihlukene kanye nokuthelelana kwezilwane ezihlukene.
Longevity, densely packed colonies, close social interaction and strong ability to fly are all favourable conditions for bats to be an ideal 'virus spreader'.
Impilo ende, amakoloni aminyene, ukusondelana komphakathi okuseduze kanye nekhono elinamandla lokundiza konke kuyizimo ezikahle zokuthi amalulwane abe 'umbhebhethekisi wegciwane' okahle.
On the other hand, MERS-CoV has been introduced to dromedary camels for decades.
Ngakolunye uhlangothi, sekungamakhulu eminyaka i-MERS-CoV yethulwe kumakamela e-dromedary.
It is well adapted to these camels that have turned from an intermediate host to a stable and natural reservoir host.
Ivumelaniseke kahle kulawa makamela aphenduke ekubeni umbungazi omaphakathi aba umbungazi ozinzile nongumthombo ongokwemvelo.
MERS-CoV causes very mild disease and maintains a relatively low mutation rate in these animals.
I-MERS-CoV ibangela ukugula okuncane futhi inezinga lokushintsha eliphansi kulezi zilwane.
Its sporadic transmission to humans is an accident and humans remain a dead-end host of MERS-CoV as its transmission cannot be sustained.
Ukutheleleka kwayo kubantu kuyiphutha futhi abantu bahlala bengumbungazi wokugcina we-MERS-CoV njengoba ukudluliswa kwayo kungakwazi ukulondolozwa.
In contrast to the role of camels in the transmission of MERS-CoV, the role of pangolins, if there is any, in the transmission of SARS-CoV-2 is different.
Ngokungafani nendima yamakamela ekudlulisweni kwe-MERS-CoV, indima yama-pangolin, uma ikhona, ekudlulisweni kwe-SARS-CoV-2 ihlukile.
Particularly, pangolin beta-CoVs are highly pathogenic in pangolins.
Ngokukhethekile, ama-beta-CoV e-pangolin abangela ukugula kakhulu kuma-pangolin.
They might be a dead-end host for SARS-CoV-2-related beta-CoVs, similar to civets in the case of SARS-CoV.
Angase abe umbungazi wokugcina wama-beta-CoV ahlobene ne-SARS-CoV-2, ngokufana nama-civet esimweni se-SARS-CoV.
Several possibilities for interspecies transmission of SARS-CoV-2 from animals to humans have to be ruled in or ruled out in future studies.
Amathuba ambalwa okuthelelana kwezidalwa ezingafani nge-SARS-CoV-2 kusukela ezilwaneni kuye kubantu kufanele zicatshangelwe noma zingacatshangelwa kuzingcwaningo zesikhathi esizayo.
First, bats could be the reservoir host of a SARS-CoV-2-related virus almost identical to SARS-CoV-2.
Okokuqala, amalulwane kungenzeka abe umbungazi ongumthombo wegciwane elihlobene ne-SARS-CoV-2 elicishe lifane ne-SARS-CoV-2.
Humans might share the ecological niche with bats through butchering or coal mining.
Abantu bangase badlale indima efanayo namalulwane ngokuhlinza izilwane noma ukumbiwa kwamalahle.
Second, pangolins could be one of intermediate amplifying host to which a SARS-CoV-2-related virus had been newly introduced.
Okwesibili, ama-pangolin angase abe umbungazi okhulisayo omaphakathi lapho igciwane elihlobene ne-SARS-CoV-2 lisanda kwethulwa khona.
Humans contract the virus through butchering and consumption of game meat.
Abantu batheleleka ngegciwane ngokuhlinza nokudla inyama ezingelwayo.
It is possible that many mammals including domestic animals are susceptible to SARS-CoV-2.
Kungenzeka ukuthi izilwane eziningi ezincelayo okuhlanganisa nezilwane ezifuywayo zingachayeka ku-SARS-CoV-2.
A survey of domestic and wild animals for antibodies is warranted.
Kudingeka inhlolovo yezivikeli-mzimba zezilwane ezifuywayo nezasendle.
Third, as mentioned above, recombination and adaptation of SARS-CoV-2 might have occurred in a third species that has contact with both bats and pangolins.
Okwesithathu, njengoba kushiwo ngenhla, ukuhlanganiswa kabusha nokuvunyelaniswa nesimo kwe-SARS-CoV-2 kungenzeka kwenzeke esilwaneni sesithathu esixhumene nakho kokubili amalulwane nama-pangolin.
The search for the animal origins of SARS-CoV-2 is still on.
Ukucingwa kwesilwane esiwumsuka we-SARS-CoV-2 kusaqhubeka.
Apart from different types of the animal hosts, three major factors on the viral side are also important in facilitating CoVs to cross species barriers.
Ngaphandle kwezinhlobo ezihlukahlukene zababungazi abayizilwane, kunezici ezintathu ezinkulu ohlangothini lwegciwane ezibalulekile ekwenzeni ama-CoV eqe umngcele wezidalwa.
First of all, their relatively high mutation rates in RNA replication.
Okokuqala, inani lawo eliphakeme loshintsho ekuphindweni kwe-RNA.
In comparison to other single-stranded RNA viruses, the estimated mutation rates of CoVs could be regarded as “moderate” to “high” with an average substitution rate being ~10-4 substitution per year per site 2, depending on the phase of CoV adaptation to novel hosts.
Uma kuqhathaniswa namanye amagciwane e-RNA anomucu owodwa, isilinganiso samanani oshintsho lwama-CoV singase sibhekwe “njengesincane” kuye “kwesiphakeme” ngokwesilinganiso soshintsho esingu ~10-4 unyaka ngamunye ngesikhungo ngasinye sesi-2, kuye ngesigaba sokuvumelanisa kwe-CoV kubabungazi abasha.
CoVs have a proof-reading exoribonuclease, deletion of which results in exceedingly high mutability and attenuation or even inviability.
Ama-CoV ane-exoribonuclease yokufuna amaphutha, ukususwa kwayo kuphumela ekushintsheni okuphakeme kakhulu nasekwehleni kwamandla noma ukungakwazi ukukhula ngendlela efanele.
Interestingly, the nucleotide analogue Remdesivir is known to suppress CoV replication through inhibition of this exoribonuclease and the RNA-dependent RNA polymerase.
Ngokuthakazelisayo, i-nucleotide analogue Remdesivir iyaziwa ukuthi icindezela ukuphindeka kwe-CoV ngokuvinjwa kwale exoribonuclease kanye ne-RNA polymerase encike ku-RNA.
Remdesivir is one of most promising anti-SARS-CoV-2 agents to be tested in clinical trials.
I-Remdesivir ingenye yama-ejenti athembisa kakhulu alwa ne-SARS-CoV-2 ezohlolwa kuzingcwaningo zokwelashwa.
Nevertheless, mutation rates of CoVs are about a million times higher than those of their hosts.
Noma kunjalo, amanani oshintsho lwama-CoV aphakeme cishe ngesigidi kunalawo ababungazi.
In addition, mutation rate is often high when CoVs are not well adapted to the host.
Ngaphezu kwalokho, inani loshintsho livame ukuba phezulu uma ama-CoV engavumelanisiwe kahle nombungazi.
Compared to SARS-CoV with a high mutation rate, the mutation rate of SARS-CoV-2 is apparently lower, suggestive of a higher level of adaptation to humans.
Uma kuqhathaniswa ne-SARS-CoV enenani loshintsho eliphakeme, inani loshintsho le-SARS-CoV-2 libonakala liphansi, okusikisela izinga eliphezulu lokuvunyelaniswa nabantu.
Presumably, it has already been adapted to another host close to humans.
Kucatshangelwa ukuthi, kungenzeka selivunyelanisiwe kakade nomunye umbungazi osondelene nabantu.
In addition to SARS-CoV-2, this also applies to MERS-CoV, which is well adapted to dromedary camels.
Ngaphezu kwe-SARS-CoV-2, lokhu kuphinde kusebenze ku-MERS-CoV, evumelana kahle namakamela e-dromedary.
Theoretically, it is unlikely that genetic drift would render vaccines and antivirals against SARS-CoV-2 ineffective quickly.
Kucatshangelwa ukuthi cishe akunakwenzeka ukuthi ushintsho lwezakhi zofuzo lungabangela imigomo nemishanguzo yamagciwane emelene ne-SARS-CoV-2 ukuthi ingasebenzi ngokushesha.
Second, the large RNA genome in CoVs exerts extra plasticity in genome modification for mutations and recombination, thereby increasing the probability for interspecies co-evolution, which is advantageous for the emergence of novel CoVs when the conditions become appropriate.
Okwesibili, i-genome enkulu ye-RNA kuma-CoV isebenzisa ukuthamba okwengeziwe ekushintshweni kwe-genome kushintsho nokuhlanganiswa kabusha, ngaleyo ndlela kunyuswe ithuba le-co-evolution yezidalwa ezihlukahlukene, elizuzisayo ekuveleni kwama-CoV amasha lapho izimo zifaneleka.
This is supported by the copious unique open reading frames and protein functions encoded towards the 3′ end of the genome.
Lokhu kusekelwa amafreyimu ahlukile amaningi okufunda avulekile nokusebenza kwephrotheni akhiqizelwa isiphetho esingu-3′ se-genome.
Third, CoVs randomly and frequently switch templates during RNA replication through a unique “copy-choice” mechanism.
Okwesithathu, ama-CoV ahlalal ashintsha amathempulethi ngokungahleliwe phakathi nokuphindwa kwe-RNA ngendlela ehlukile “yokukhetha-kokukopisha”.
In a host that serves as the mixing vessel, strand switching occurs frequently during CoV RNA transcription.
Kumbungazi osebenza njengesitsha sokuxuba, ukushintsha kohlobo kwenzeka njalo phakathi ne-transcription ye-CoV RNA.
Highly homologous full-length and subgenomic RNAs could recombine to generate new CoVs.
Ama-RNA a-homologous kakhulu anobude obugcwele kanye na-subgenomic angase ahlangane kabusha ukuze akhe ama-CoV amasha.
Phylogenetic evidence of natural recombination has been found in both HCoV-HKU1 and HCoV-OC43, as well as animal CoVs such as bat SL-CoV and batCoV-HKU9.
Ubufakazi obuyi-phylogenetic bokuhlanganiswa kabusha okungokwemvelo butholwe kukho kokubili i-HCoV-HKU1, i-HCoV-OC43, kanye nama-CoV esilwane njenge-SL-CoV yelulwane kanye ne-batCoV-HKU9.
Virus-host interaction in relation to transmission
Ukusebenzisana kwegciwane nombungazi ngokuqondene nokutheleleka
Besides three viral factors stated above, viral interaction with host receptor is another key factor influential on interspecies transmission.
Ngaphandle kwezici ezintathu zegciwane ezishiwo ngenhla, ukusebenzisana kwegciwane nesisabeli sombungazi kungesinye isici esiyinhloko esinethonya ekuthelelaneni kwezidalwa ezingafani.
Herein, recombination of SARS-CoV is taken as a typical example, which also showed evidence of positive selection during interspecies transmission events.
Lapha, ukuhlanganiswa kabusha kwe-SARS-CoV kubhekwa njengesibonelo esivamile, esabonisa ubufakazi bokukhethwa okuphozithivu phakathi nezehlakalo zokuthelelana kwezidalwa ezihlukene.
Based on the comparative analysis between isolates of human and civet SARS-CoVs, SARS-CoV is thought to undergo rapid adaptation in different hosts, particularly with mutations at the RBD of the S protein.
Ngokusekelwe ekuhlaziyweni okuqhathanisayo phakathi kwabantu abahlukanisiwe kanye nama-SARS-CoV e-civet, kucatshangelwa ukuthi i-SARS-CoV ibhekana nokuvumelana nesimo okusheshayo kubabungazi abahlukene, ikakhulukazi ngoshintsho ku-RBD yephrotheni ka-S.
Generally, the RBD in the S protein of a CoV interacts with the cellular receptor and is intensely selected by the host antibody response.
Ngokuvamile, i-RBD kuphrotheni ka-S ye-CoV isebenzisana nesisabeli seseli futhi ikhethwa ngokuqinile ukusabela kwesivikeli-mzimba sombungazi.
In SARS-CoV, the RBD is in the 318th to 510th amino acids on the S1 fragment, which binds to the human ACE2 as well as its coreceptors for viral entry.
Ku-SARS-CoV, i-RBD ikuma-amino acid esi-318 kuye kweyesi-510 engxenyeni ye-S1, enamathela ku-ACE2 yomuntu kanye nama-coreceptor ayo ukuze kungene igciwane.
The RBD of SARS-CoV is capable of recognizing the ACE2 receptors of various animals, including bat, civet, mouse and raccoon dog, allowing interspecies transmission of the virus.
I-RBD ye-SARS-CoV iyakwazi ukubona izisabeli ze-ACE2 yezilwane ezihlukene, okuhlanganisa ilulwane, i-civet, igundane nenja ye-raccoon, okuvumela ukuthelelana ngegciwane kwezidalwa ezihlukene.
In fact, only 6 amino acid residues were observed to be different from human and civet viral isolates in the RBD and 4 of them locate in the receptor-binding motif for interaction with the ACE2 receptor.
Eqinisweni, izinsalela ezingu-6 kuphela ze-amino acid okwaphawulwa ukuthi zihlukile kokuhlukanisiwe kwegciwane labantu kanye ne-civet ku-RBD okungu-4 kukho kutholakala ku-motif enamathela kusisabeli ukuze isebenzelane nesisabeli se-ACE2.
Civet SARS-CoV has K479N and S487T mutations in its RBD, which might increase the affinity of the interaction of spike protein with human ACE2 receptor.
I-SARS-CoV ye-civet inoshintsho lwe-K479N kanye ne-S487T ku-RBD yayo, okungase kunyuse izinga lokuhlangana lokusebenzelana kwephrotheni ye-spike nesisabeli se-ACE2 yomuntu.
In other words, these two amino acid substitutions might be critical to viral adaption to humans.
Ngamanye amazwi, lolu shintsho lwama-amino acid amabili lungase lubaluleke ekuvumelanisweni kwegciwane kubantu.
It is noteworthy that SARS-CoV-2 shares the same cellular receptor with SARS-CoV.
Kuyaphawuleka ukuthi i-SARS-CoV-2 inesisabeli esifanayo seseli ne-SARS-CoV.
A 30% difference between SARS-CoV-2 and SARS-CoV in the S1 unit of the S protein implicates that the binding affinity of its S protein with human ACE2 might have altered.
Umehluko ka-30% phakathi kwe-SARS-CoV-2 ne-SARS-CoV kuyunithi ye-S1 yephrotheni ka-S usho ukuthi izinga lokuhlangana lephrotheni lika-S ne-ACE2 yabantu kungenzeka ukuthi lishintshile.
Indeed, a cryo-EM study indicates a 10- to 20-fold higher affinity of this binding than that between human ACE2 and SARS-CoV S protein.
Empeleni, ucwaningo lwe-cryo-EM libonisa izinga eliphakeme lokugoqa okungu-10- ukuya ku-20- lalokhu kugoqa kunalokho okuphakathi kwe-ACE2 yabantu nephrotheni ka-S ye-SARS-CoV.
It will also be of interest to determine whether any other coreceptor might be required for SARS-CoV-2 transmission.
Kuzophinde futhi kuthakazelise ukunquma ukuthi ingabe iyadingeka yini enye i-coreceptor ekuthelelekeni kwe-SARS-CoV-2.
Intriguingly, HCoV-NL63 also binds to ACE2 but with a different part of S.
Ngokuthakazelisayo, i-HCoV-NL63 iphinde inamathele ku-ACE2 kodwa ngengxenye ehlukile ka-S.
There exist many other HCoV receptors, such as aminopeptidase N for HCoV-229E, and 9-O-acetylated sialic acid for HCoV-OC43.
Kukhona ezinye izisabeli ze-HCoV, njengama-aminopeptidase N e-HCoV-229E, kanye ne-9-O-acetylated sialic acid ye-HCoV-OC43.
They might also account for successful adaptation of these CoVs in humans after interspecies transmission from their animal hosts.
Angase futhi abhekwe njengesizathu sokuzivumelanisa ngempumelelo kwama-CoV kubantu ngemva kokuthelelana kwezidalwa ezihlukene esuka kubabungazi bawo abayizilwane.
In addition to cellular receptors, the outcome of interspecies transmission of HCoVs is also governed by other host dependency and restriction factors.
Ngaphezu kwezisabeli ezingamaseli, umphumela wokuthelelana kwezidalwa ezihlukene ngama-HCoV uphinde futhi ulawulwe ukuncika kwesinye isidalwa nezici zomkhawulo.
The divergence of these host proteins between humans and natural reservoir hosts of HCoVs such as bats, dromedary camels and rodents might constitute a barrier to interspecies transmission.
Ukwehluka kwalawa maphrotheni ombungazi phakathi kwabantu nababungazi abawumthombo ongokwemvelo wama-HCoV njengamalulwane, amakamela e-dromedary kanye namagundane kungase kubangele umngcele wokuthelelana kwezidalwa ezihlukene.
HCoVs have to usurp host dependency factors and subvert host restriction factors for a successful interspecies transmission.
Ama-HCoV kufanele athathe izici zokuncika kumnikazi futhi aphazamise izici zokuvimvela kombungazi ukuze kube nokuthelelana kwezidalwa okuyimpumelelo.
In this regard, molecular determinants in this important area of virus-host interaction remain to be identified and characterized.
Ngokuqondene nalokhu, izinqumi ezingamangqamuzana kule ndawo ebalulekile yokusebenzelana nombungazi wegciwane zisazobonwa futhi ziphawulwe.
An unbiased genome-wide screening of host dependency and restriction factors for SARS-CoV-2 using the state-of-the-art technology of CRISPR might be fruitful.
Ukuhlungwa okubanzi kwe-genome okungachemile kokuncika kombungazi kanye nezici zokukhawulwa ze-SARS-CoV-2 ngokusebenzisa ubuchwepheshe besimanje be-CRISPR kungase kuzuzise.
Emergence of novel HCoVs: back to ground zero
Ukuqhamuka kwama-HCoV amasha: ukubuyela ekuqaleni
The diversity of bat CoVs provides ample opportunities for the emergence of novel HCoVs.
Ukwehlukahluka kwama-CoV elulwane kunikeza amathuba amaningi okuvela kwama-HCoV amasha.
In this sense, bat CoVs serve as the gene pool of HCoVs.
Ngalo mqondo, ama-CoV elulwane asebenza njengeqoqo lezakhi zofuzo zama-HCoV.
In addition, rapid mutation and genetic recombination also drive HCoV evolution and serve as two important steps in this process.
Ngaphezu kwalokho, ushintsho olusheshayo kanye nokuhlanganiswa kabusha kwezakhi zofuzo kuphinde kuqhube ukuziphendukela kwe-HCoV futhi kusebenza njengezinyathelo ezimbili ezibalulekile kule nqubo.
For example, the acquisition or loss of novel protein-coding genes has the potential to drastically modify viral phenotypes.
Ngokwesibonelo, ukutholwa noma ukulahleka kwezakhi zofuzo ezenza ikhodi yephrotheni entsha kunamandla okuwashintsha kakhulu ama-phenotype egciwane.
Among SARS-CoV accessory proteins, ORF8 has been thought to be important in adaptation to humans, as SARS-CoV-related bat viruses were isolated but found to encode divergent ORF8 proteins.
Phakathi kwamaphrotheni ayinsiza e-SARS-CoV, i-ORF8 kucatshangwa ukuthi ibalulekile ekuzivumelaniseni nabantu, njengoba amagciwane elulwane ahlobene ne-SARS-CoV ahlukaniswa kodwa atholwa ekhiqiza amaphrotheni e-ORF8 ahlukile.
A 29-nucleotide deletion characteristic of SARS-CoVs has been found in strains isolated at the beginning of the human epidemic.
Isici sokususwa kwe-29-nucleotide sama-SARS-CoV sitholwe ezinhlotsheni ezihlukanisiwe ekuqaleni komqedazwe wabantu.
This deletion splits ORF8 into ORF8a and ORF8b and is thought to be an adaptive mutation that promotes the switch of hosts.
Lokhu kususwa kuhlukanisa i-ORF8 ibe i-ORF8a kanye ne-ORF8b futhi kucatshangwa ukuthi iwushintsho oluzivumelanisayo olukhuthaza ukushintshwa kwababungazi.