RESUMO
The animal reservoir of SARS-CoV-2 is unknown despite reports of SARS-CoV-2-related viruses in Asian Rhinolophus bats1-4, including the closest virus from R. affinis, RaTG13 (refs. 5,6), and pangolins7-9. SARS-CoV-2 has a mosaic genome, to which different progenitors contribute. The spike sequence determines the binding affinity and accessibility of its receptor-binding domain to the cellular angiotensin-converting enzyme 2 (ACE2) receptor and is responsible for host range10-12. SARS-CoV-2 progenitor bat viruses genetically close to SARS-CoV-2 and able to enter human cells through a human ACE2 (hACE2) pathway have not yet been identified, although they would be key in understanding the origin of the epidemic. Here we show that such viruses circulate in cave bats living in the limestone karstic terrain in northern Laos, in the Indochinese peninsula. We found that the receptor-binding domains of these viruses differ from that of SARS-CoV-2 by only one or two residues at the interface with ACE2, bind more efficiently to the hACE2 protein than that of the SARS-CoV-2 strain isolated in Wuhan from early human cases, and mediate hACE2-dependent entry and replication in human cells, which is inhibited by antibodies that neutralize SARS-CoV-2. None of these bat viruses contains a furin cleavage site in the spike protein. Our findings therefore indicate that bat-borne SARS-CoV-2-like viruses that are potentially infectious for humans circulate in Rhinolophus spp. in the Indochinese peninsula.
Assuntos
COVID-19 , Quirópteros , Enzima de Conversão de Angiotensina 2 , Animais , Ásia , Cavernas , Quirópteros/virologia , Reservatórios de Doenças , Humanos , Ligação Proteica , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/químicaRESUMO
As part of the characterization of viral communities of Laotian batflies, we report here the sequencing of six nearly complete genome segments of a novel reovirus identified in Laotian batflies that is distantly related to reoviruses recently reported in various Diptera species.
RESUMO
Between May and June 2015, 512 bats, six rodents, and six tree-shrews were examined for ectoparasites in Vientiane and Khammouane Provinces, Laos. Thirty-seven ticks (33 females and four males) identified as Ixodes granulatus Supino were collected from four individuals of the Northern tree-shrew, Tupaia belangeri (Wagner) (Scandentia:Tupaiidae), and one female of Ixodes vespertilionis Koch was collected from one individual of the Intermediate Leaf-nosed Bat, Hipposideros larvatus (Horsfield) (Chiroptera:Hipposideridae). This appears to be the first record of I. vespertilionis from Laos, as well as the first record of this host-parasite relationship in the Southeast Asia region.
Assuntos
Distribuição Animal , Quirópteros , Interações Hospedeiro-Parasita , Ixodes/fisiologia , Infestações por Carrapato/veterinária , Tupaiidae , Animais , Feminino , Laos/epidemiologia , Masculino , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologiaRESUMO
A new species of the flying squirrel genus Biswamoyopterus is described from Lao PDR. It is based on a single specimen collected from a local food market at Ban Thongnami, Pak Kading District, Bolikhamxai Province. The new taxon shows close affinities to Biswamoyopterus biswasi, which is only known from the holotype collected in 1981, 1250 km from the current locality, in Arunachal Pradesh, Northeast India. However, it differs substantially in pelage colour, most particularly on the ventral surfaces of the body, patagia, tail membrane, and tail. The single specimen was found in an area of central Lao PDR, which is characterised by its extensive limestone karst formations and which is home to other rare endemic rodents, including the Khanyou (Laonastes aenigmamus) nd the Lao limestone rat (Saxatilomyspaulinae).