Review of Bats and SARS

TOC Summary: The discovery of SARS-like coronaviruses in horseshoe bats highlights the possibility of future outbreaks caused by different coronaviruses of bat origin

Two Mutations Were Critical for Bat-to-Human Transmission of Middle East Respiratory Syndrome Coronavirus

To understand how Middle East respiratory syndrome coronavirus (MERS-CoV) transmitted from bats to humans, we compared the virus surface spikes of MERS-CoV and a related bat coronavirus, HKU4. Although HKU4 spike cannot mediate viral entry into human cells, two mutations enabled it to do so by allowing it to be activated by human proteases. These mutations are present in MERS-CoV spike, explaining why MERS-CoV infects human cells. These mutations therefore played critical roles in the bat-to-human transmission of MERS-CoV, either directly or through intermediate hosts

Isolation and characterization of a novel alphanodavirus

<p>Abstract</p> <p>Background</p> <p><it>Nodaviridae </it>is a family of non-enveloped isometric viruses with bipartite positive-sense RNA genomes. The <it>Nodaviridae </it>family consists of two genera: alpha- and beta-nodavirus. Alphanodaviruses usually infect insect cells. Some commercially available insect cell lines have been latently infected by Alphanodaviruses.</p> <p>Results</p> <p>A non-enveloped small virus of approximately 30 nm in diameter was discovered co-existing with a recombinant <it>Helicoverpa armigera </it>single nucleopolyhedrovirus (<it>Hear</it>NPV) in Hz-AM1 cells. Genome sequencing and phylogenetic assays indicate that this novel virus belongs to the genus of alphanodavirus in the family <it>Nodaviridae </it>and was designated HzNV. HzNV possesses a RNA genome that contains two segments. RNA1 is 3038 nt long and encodes a 110 kDa viral protein termed protein A. The 1404 nt long RNA2 encodes a 44 kDa protein, which exhibits a high homology with coat protein precursors of other alphanodaviruses. HzNV virions were located in the cytoplasm, in association with cytoplasmic membrane structures. The host susceptibility test demonstrated that HzNV was able to infect various cell lines ranging from insect cells to mammalian cells. However, only Hz-AM1 appeared to be fully permissive for HzNV, as the mature viral coat protein essential for HzNV particle formation was limited to Hz-AM1 cells.</p> <p>Conclusion</p> <p>A novel alphanodavirus, which is 30 nm in diameter and with a limited host range, was discovered in Hz-AM1 cells.</p

Differential stepwise evolution of SARS coronavirus functional proteins in different host species

<p>Abstract</p> <p>Background</p> <p>SARS coronavirus (SARS-CoV) was identified as the etiological agent of SARS, and extensive investigations indicated that it originated from an animal source (probably bats) and was recently introduced into the human population via wildlife animals from wet markets in southern China. Previous studies revealed that the spike (S) protein of SARS had experienced adaptive evolution, but whether other functional proteins of SARS have undergone adaptive evolution is not known.</p> <p>Results</p> <p>We employed several methods to investigate selective pressure among different SARS-CoV groups representing different epidemic periods and hosts. Our results suggest that most functional proteins of SARS-CoV have experienced a stepwise adaptive evolutionary pathway. Similar to previous studies, the spike protein underwent strong positive selection in the early and middle phases, and became stabilized in the late phase. In addition, the replicase experienced positive selection only in human patients, whereas assembly proteins experienced positive selection mainly in the middle and late phases. No positive selection was found in any proteins of bat SARS-like-CoV. Furthermore, specific amino acid sites that may be the targets of positive selection in each group are identified.</p> <p>Conclusion</p> <p>This extensive evolutionary analysis revealed the stepwise evolution of different functional proteins of SARS-CoVs at different epidemic stages and different hosts. These results support the hypothesis that SARS-CoV originated from bats and that the spill over into civets and humans were more recent events.</p

Type III IFN Receptor Expression and Functional Characterisation in the Pteropid Bat, Pteropus alecto

Bats are rich reservoir hosts for a variety of viruses, many of which are capable of spillover to other susceptible mammals with lethal consequences. The ability of bats to remain asymptomatic to viral infection may be due to the rapid control of viral replication very early in the immune response through innate antiviral mechanisms. Type I and III interferons (IFNs) represent the first line of defence against viral infection in mammals, with both families of IFNs present in pteropid bats. To obtain further insight into the type III IFN system in bats, we describe the characterization of the type III IFN receptor (IFNλR) in the black flying fox, P. alecto with the characterization of IFNλR1 and IL10R2 genes that make up the type III IFN receptor complex. The bat IFNλR complex has a wide tissue distribution and at the cellular level, both epithelial and immune cells are responsive to IFN-λ treatment. Furthermore, we demonstrate that the bat IFNλR1 chain acts as a functional receptor. To our knowledge, this report represents the first description of an IFN receptor in any species of bat. The responsiveness of bat cells to IFN-λ support a role for the type III IFN system by epithelial and immune cells in bats

Need for continual education about disaster medicine for health professionals in China-a pilot study

<p>Abstract</p> <p>Background</p> <p>Disaster Medicine training is not included in medical education curriculum in China, even though the country has suffered various disasters annually. We intended to assess the need for continual education regarding disaster management for health professionals in China.</p> <p>Methods</p> <p>A survey was conducted among 324 health professionals who participated in the response to the Wenchuan earthquake medical relief and public health assessment in October, 2008.</p> <p>Results</p> <p>The most of participants (67.3%) received informal disaster medicine training, and only a few (12.7%) participated in disaster drills. Most of the participants wanted to get continual education about disaster medicine training (89.8%), but prefer on-line training course for the flexibility of time scheduling and travel through China.</p> <p>Conclusion</p> <p>The need for continual disaster medicine training is high; health professionals should be equipped with knowledge and skills for disaster management.</p

World Society for Virology first international conference: Tackling global virus epidemics.

Funder: Department of Health, Australian GovernmentThis communication summarizes the presentations given at the 1st international conference of the World Society for Virology (WSV) held virtually during 16-18 June 2021, under the theme of tackling global viral epidemics. The purpose of this biennial meeting is to foster international collaborations and address important viral epidemics in different hosts. The first day included two sessions exclusively on SARS-CoV-2 and COVID-19. The other two days included one plenary and three parallel sessions each. Last not least, 16 sessions covered 140 on-demand submitted talks. In total, 270 scientists from 49 countries attended the meeting, including 40 invited keynote speakers

World Society for Virology first international conference: Tackling global virus epidemics

This communication summarizes the presentations given at the 1st international conference of the World Society for Virology (WSV) held virtually during 16–18 June 2021, under the theme of tackling global viral epidemics. The purpose of this biennial meeting is to foster international collaborations and address important viral epidemics in different hosts. The first day included two sessions exclusively on SARS-CoV-2 and COVID-19. The other two days included one plenary and three parallel sessions each. Last not least, 16 sessions covered 140 on-demand submitted talks. In total, 270 scientists from 49 countries attended the meeting, including 40 invited keynote speakers.Peer reviewe

Human-animal interactions and bat coronavirus spillover potential among rural residents in Southern China

Human interaction with animals has been implicated as a primary risk factor for several high impact zoonoses, including many bat-origin viral diseases; however, the animal-to-human spillover events that lead to emerging diseases are rarely observed or clinically examined, and the link between specific interactions and spillover risk is poorly understood. To investigate this phenomenon, we conducted biological-behavioral surveillance among rural residents in the Yunnan, Guangxi, and Guangdong provinces of Southern China, where we have identified a number of SARS-related coronaviruses in bats. Serum samples were tested for four bat-borne coronaviruses using newly developed enzyme-linked immunosorbent assays (ELISA). Survey data were used to characterize associations between human-animal contact and bat coronavirus spillover risk. A total of 1,596 residents were enrolled in the study from 2015 to 2017. Nine participants (0.6%) tested positive for bat coronaviruses. 265 (17%) participants reported severe acute respiratory infection (SARI) and/or influenza-like illness (ILI) symptoms in the past year, which were associated with poultry, carnivore, rodent/shrew, and bat contact, with variability by family income and province of residence. This study provides serological evidence of bat coronavirus spillover in rural communities in Southern China. The low seroprevalence observed in this study suggests that bat coronavirus spillover is a rare event. Nonetheless, this study highlights associations between human-animal interaction and zoonotic spillover risk. These findings can be used to support targeted biological behavioral surveillance in high-risk geographic areas in order to reduce the risk of zoonotic disease emergence