Project description:ACE2 on epithelial cells is the SARS-CoV-2 entry receptor. Single-cell RNA-sequencing data derived from two COVID-19 cohorts revealed that MAP4K3/GLK-positive epithelial cells were increased in patients. SARS-CoV-2-induced GLK overexpression in epithelial cells correlated with COVID-19 severity and vesicle secretion. GLK overexpression induced the epithelial cell-derived exosomes containing ACE2; the GLK-induced exosomes transported ACE2 proteins to recipient cells, facilitating pseudovirus infection. Consistently, ACE2 proteins were increased in the serum exosomes from another COVID-19 cohort. Remarkably, SARS-CoV-2 spike protein stimulated GLK, and GLK stabilized ACE2 in epithelial cells. Mechanistically, GLK phosphorylated ACE2 at two serine residues (Ser776, Ser783), leading to dissociation of ACE2 from its E3 ligase UBR4. Reduction of UBR4-induced Lys48-linked ubiquitination at three lysine residues (Lys26, Lys112, Lys114) of ACE2 prevented its degradation. Furthermore, SARS-CoV-2 pseudovirus or live virus infection in humanized ACE2 mice induced GLK and ACE2 protein levels, as well as ACE2-containing exosomes. Collectively, ACE2 stabilization by SARS-CoV-2-induced MAP4K3/GLK may contribute to the pathogenesis of COVID-19.
Project description:Bat sarbecovirus BANAL-236 is highly related to SARS-CoV-2 and infects human cells, albeit lacking the furin cleavage site in its spike protein. BANAL-236 replicates efficiently and pauci-symptomatically in humanized mice and in macaques, where its tropism is enteric, strongly differing from that of SARS-CoV-2. BANAL-236 infection leads to protection against superinfection by a virulent strain. We find no evidence of antibodies recognizing bat sarbecoviruses in populations in close contact with bats in which the virus was identified, indicating that such spillover infections, if they occur, are rare. Six passages in humanized mice or in human intestinal cells, mimicking putative early spillover events, select adaptive mutations without appearance of a furin cleavage site and no change in virulence. Therefore, acquisition of a furin site in the spike protein is likely a pre-spillover event that did not occur upon replication of a SARS-CoV-2-like bat virus in humans or other animals. Other hypotheses regarding the origin of the SARS-CoV-2 should therefore be evaluated, including the presence of sarbecoviruses carrying a spike with a furin cleavage site in bats.
Project description:Wastewater-based epidemiology is a corroborated environmental surveillance tool in the global fight against SARS-CoV-2. The analysis of wastewater for detection of SARS-CoV-2 RNA may assist policymakers to survey a specific infectious community. Herein, we report on a long-term quantification study in Bahrain to investigate the incidence of the SARS-CoV-2 RNA in wastewater during the COVID-19 pandemic. The ∼260,000 population of Muharraq Island in Bahrain is served by a discrete sewerage catchment, and all wastewater flows to a single large Sewage Treatment Plant (STP) with a capacity of 100,000 m3/day. The catchment is predominately domestic, but also serves several hospitals and Bahrain's international airport. Flow-weighted 24-h composite wastewater samples for the period February 2020 to October 2021 were analyzed for the presence of SARS-CoV-2 N1, N2 and E genes. A Spearman rank correlation demonstrated a moderate correlation between the concentration of SARS-CoV-2 N1, N2 and E genes in the wastewater samples and the number of COVID-19 cases reported on the same day of the sampling. SARS-CoV-2 viral genes were detected in wastewater samples shortly after the first cases of COVID-19 were reported by the health authorities in Bahrain by reverse transcription-polymerase chain reaction (RT-qPCR). The viral genes were detected in 55 of 65 samples (84.62%) during the whole study period and the concentration range was found to be between 0 and 11,508 RNA copies/mL across the viral genes tested (in average N1: 518.4, N2: 366.8 and E: 649.3 copies/mL). Furthermore, wastewater samples from two COVID-19-dedicated quarantine facilities were analysed and detected higher SARS-CoV-2 gene concentrations (range 27-19,105 copies/mL; in average N1: 5044, N2: 4833 and E: 8663 copies/mL). Our results highlight the potential use of RT-qPCR for SARS-CoV-2 detection and quantification in wastewater and present the moderate correlation between concentration of SARS-CoV-2 genes with reported COVID-19 cases for a specified population. Indeed, this study identifies this technique as a mechanism for long term monitoring of SARS-CoV-2 infection levels and hence provides public health and policymakers with a useful environmental surveillance tool during and after the current pandemic.
Project description:The challenges imposed by the ongoing outbreak of severe acute respiratory syndrome coronavirus-2 affects every aspect of our modern world, ranging from our health to our socio-economic needs. Our existence highly depends on the vaccine's availability, which demands in-depth research of the available strains and their mutations. In this work, we have analyzed all the available SARS-COV2 genomes isolated from the Kingdom of Bahrain in terms of their variance and origin analysis. We have predicted various known and unique mutations in the SARS-COV2 isolated from Bahrain. The complexity of the phylogenetic tree and dot plot representation of the strains mentioned above with other isolates of Asia indicates the versatility and multiple origins of Bahrain's SARS-COV2 isolates. We have also identified two high impact spike mutations from these strains which increase the virulence of SARS-COV2. Our research could have a high impact on vaccine development and distinguishes the source of SARS-COV2 in the Kingdom of Bahrain.
Project description:As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has surged across the globe, great effort has been expended to understand mechanisms of transmission and spread. From a hospital perspective, this topic is critical to limit and prevent SARS-CoV-2 iatrogenic transmission within the healthcare environment. Currently, the virus is believed to be transmitted primarily through respiratory droplets, but a growing body of evidence suggests that spread is also possible through aerosolized particles and fomites. Amidst a growing volume of patients with coronavirus disease 2019 (COVID-19), the purpose of this study was to evaluate the potential for SARS-CoV-2 transmission through fomites. Samples collected from the exposed skin of clinicians (n = 42) and high-touch surfaces (n = 40) were collected before and after encounters with COVID-19 patients. Samples were analyzed using two assays: the CDC 2019-nCoV Real-Time Reverse Transcription polymerase chain reaction (RT-qPCR) assay, and a SYBR Green assay that targeted a 121 bp region within the S-gene of SARS-CoV-2. None of the samples tested positive with the CDC assay, while two high-touch surface areas tested positive for SARS-CoV-2 using the Spike assay. However, viral culture did not reveal viable SARS-CoV-2 from the positive samples. Overall, the results from this study suggest that SARS-CoV-2 RNA were not widely present either on exposed skin flora or high-touch surface areas in the hospital locations tested. The inability to recover viable virus from samples that tested positive by the molecular assays, however, does not rule out the possibility of SARS-CoV-2 transmission through fomites.
Project description:ObjectivesSchool closure during the coronavirus disease 2019 (COVID-19) pandemic resulted in a negative impact on children. Serial testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proposed as a measure for safety school reopening. We aimed to study the usefulness of SARS-CoV-2 surveillance by saliva testing and performing wastewater surveillance for SARS-CoV-2 in a day school in a resource-limited setting.MethodsWe conducted a cluster randomized study to investigate the potential use of saliva antigen testing compared to saliva pooling for nucleic acid detection in a primary school in Thailand from December 2021 to March 2022. Wastewater surveillance in the school was also performed.ResultsA total of 484 participants attended the study. SARS-CoV-2 was detected in two participants from the tests provided by the study (one in the pool nucleic acid test arm, and another in the quantitative antigen test arm). Additional ten participants reported positive results on an additional rapid antigen test (RAT) performed by nasal swab when they had symptoms or household contact. There was no difference among arms in viral detection by intention-to-treat and per protocol analysis (p = 0.304 and 0.894, respectively). We also investigated the feasibility of wastewater surveillance to detect the virus in this setting. However, wastewater surveillance could not detect the virus.ConclusionsIn a low COVID-19 prevalence, serial saliva testing and wastewater surveillance for SARS-CoV-2 rarely detected the virus in a day school setting. Performing RAT on nasal swabs when students, teachers or staff have symptoms or household contact might be more reasonable.
Project description:In this study, we report the implementation of a comprehensive wastewater surveillance testing program at a university campus in Singapore to identify Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infected individuals and the usage of pharmaceuticals and personal care products (PPCPs) as well as other emerging contaminants (ECs). This unique co-monitoring program simultaneously measured SARS-CoV-2 with chemical markers/contaminants as the COVID-19 situation evolved from pandemic to endemic stages, following a nationwide mass vaccination drive. SARS-CoV-2 RNA concentrations in wastewater from campus dormitories were measured using real-time reverse transcription-polymerase chain reaction (RT-qPCR) and corroborated with the number of symptomatic COVID-19 cases confirmed with the antigen rapid test (ART). Consistent results were observed where the concentrations of SARS-CoV-2 RNA detected in wastewater increased proportionately with the number of COVID-19 infected individuals residing on campus. Similarly, a wide range of ECs, including disinfectants and antibiotics, were detected through sensitive liquid chromatography with tandem mass spectrometry (LC-MS/MS) techniques to establish PPCPs consumption patterns during various stages of the COVID-19 pandemic in Singapore. Statistical correlation of SARS-CoV-2 RNA was observed with few ECs belonging to disinfectants, PCPs and antibiotics. A high concentration of disinfectants and subsequent positive correlation with the number of reported cases on the university campus indicates that disinfectants could serve as a chemical marker during such unprecedented times.
Project description:With the emergence of new SARS-Cov2 variants, critical questions have arisen about: (1) the effectiveness of the available COVID-19 vaccines developed to protect against the original Wuhan (wild type) variant and (2) the magnitude and clinical consequences of post-vaccination infections in the context of the Delta variant of SARS-Cov2. While some "real world" experiences with various vaccines have been reported, to our knowledge, few have examined comparative outcomes of various vaccines in one country as new SARS-CoV-2 variants have emerged. Here we present an analysis of COVID-19 related outcomes from a national database in Bahrain, a country with a total population of 1.51 million, where four vaccines were deployed (total vaccinated = 1,003,960 adults): AstraZeneca (AZ/Covishield), Pfizer/BioNtech, Sinopharm and Sputnik V. We compare the four vaccines, based on the following post-vaccination outcomes: SARS-CoV-2 infections, hospitalisations, ICU admissions and deaths, compared to unvaccinated individuals. We conclude that the four vaccines used in Bahrain were effective in significantly reducing all four COVID-19 related outcomes compared to unvaccinated individuals, prior to, and during the period when the Delta variant predominated in the country. However, compared to the three other vaccines, individuals vaccinated with Sinopharm vaccine had a higher risk of post-vaccination infections, hospitalisations and ICU admissions (e.g., 6.94%, 2.24%, 1.99% and 1.52% of COVID-19 cases of Sinopharm, Sputnik V, Pfizer and Covishield recipients, respectively, required hospitalisation versus 13.66% of COVID-19 cases among unvaccinated individuals); however, given the confounding factors, this needs to be confirmed by further studies. We find no evidence of biased selection for any vaccine, but note waning protection of the Pfizer/BioNtech vaccine during the January to June 2021 period in the age > 60 y cohort; however, this cannot be distinguished from the overall fall in hospitalisations overall. Our findings support the value of vaccination in preventing COVID-19 related outcomes, provide real world estimates on the outcomes and frequencies of post-vaccination infections for the four vaccines, which may inform vaccine selection in the context of the Delta variant across the globe.
Project description:To evaluate the gene expression profiling of peripheral leukocytes in different outcomes of SARS-CoV-2 infections, whole blood samples were collected from individuals with positive SARS-CoV-2 nasopharyngeal swab by RT-PCR (54 patients) and healthy uninfected individuals (12 volunteers). Infected patients were classified into mild, moderate, severe and critical groups according to a modified statement in the Novel Coronavirus Pneumonia Diagnosis and Treatment Guideline. Blood were collected into EDTA tubes and the buffy coat samples were stored in TRIzol reagent at -80 °C until use for RNA extraction. Affymetrix Clariom S array was used to perform the high-throughput gene expression profiling. Microarray analyses were performed using APT Affymetrix software, R packages and Bioconductor libraries. This systemic view of SARS-CoV-2 infections through blood transcriptomics will foster the understanding about molecular mechanisms and immunopathological processes involved in COVID-19 disease and its different outcomes.