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1.
J Gambl Stud ; 2024 May 09.
Article in English | MEDLINE | ID: mdl-38724824

ABSTRACT

Computer technology has long been touted as a means of increasing the effectiveness of voluntary self-exclusion schemes - especially in terms of relieving gaming venue staff of the task of manually identifying and verifying the status of new customers. This paper reports on the government-led implementation of facial recognition technology as part of an automated self-exclusion program in the city of Adelaide in South Australia-one of the first jurisdiction-wide enforcements of this controversial technology in small venue gambling. Drawing on stakeholder interviews, site visits and documentary analysis over a two year period, the paper contrasts initial claims that facial recognition offered a straightforward and benign improvement to the efficiency of the city's long-running self-excluded gambler program, with subsequent concerns that the new technology was associated with heightened inconsistencies, inefficiencies and uncertainties. As such, the paper contends that regardless of the enthusiasms of government, tech industry and gaming lobby, facial recognition does not offer a ready 'technical fix' to problem gambling. The South Australian case illustrates how this technology does not appear to better address the core issues underpinning problem gambling, and/or substantially improve conditions for problem gamblers to refrain from gambling. As such, it is concluded that the gambling sector needs to pay close attention to the practical outcomes arising from initial cases such as this, and resist industry pressures for the wider replication of this technology in other jurisdictions.

2.
Acta Trop ; 256: 107248, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38734359

ABSTRACT

Bats and ticks are important sources of zoonotic pathogens. Therefore, understanding the diversity, distribution, and ecology of both groups is crucial for public health preparedness. Soft ticks (Argasidae) are a major group of ectoparasites commonly associated with bats. The multi-host life cycle of many argasids make them important vectors of pathogens. Over nine years (2011-2020), surveillance was undertaken to identify the ticks associated with common bats in Singapore. During this period, the bat tick Ornithodoros batuensis was detected within populations of two cave roosting bat species: Eonycteris spelaea and Penthetor lucasi. We examined the relationship between bat species, roosting behaviour, and probability of O. batuensis infestation. We also estimated the relationship between bat life history variables (body condition index, sex, and age) on the probability of infestation and tick count. This represents the first detection of O. batuensis and the genus Ornithodoros within Singapore. We also provide evidence of the continued persistence of Argas pusillus in Singapore with the second local record.


Subject(s)
Chiroptera , Ornithodoros , Tick Infestations , Animals , Chiroptera/parasitology , Singapore/epidemiology , Female , Male , Tick Infestations/veterinary , Tick Infestations/epidemiology , Tick Infestations/parasitology , Argasidae , Argas
3.
Phys Chem Chem Phys ; 26(16): 12453-12466, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38625536

ABSTRACT

The impact of ionic liquids (ILs) on polar reactions is well recognised, however the impact of ILs on non-polar reactions is less well understood or explored. Pericyclic Cope rearrangements are highly concerted, exhibit minimal charge localisation and pass through an uncharged but well-defined transition state, and thus provide a good mechanism for exploring the impact of IL polarizability on chemical reactivity. Recently, a 10× rate enhancement has been observed for the Cope rearrangement of 3-phenyl-1,5-hexadiene in the IL 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4C1im][NTf2] compared to benzene. In this work we undertake a DFT based computational study (B3LYP-D3BJ/6-311+G(d,p) and M06-2X-D3/6-311+G(d,p)) of the Cope rearrangement of 3-phenyl-1,5-hexadiene and 3-propyl-hexa-1,5-diene in molecular solvents (acetonitrile, benzene and ethanol) and the IL [C4C1im][NTf2] using the SMD solvation model. The impact of benzene and [C4C1im][NTf2] on the Cope rearrangement of 3-phenyl-1,5-hexadiene is studied in more detail and we provide insight into the reason for the rate enhancement in an IL. The volume of activation is evaluated and the potential impact of 'solvent pressure' is discussed. We identify two potential mechanisms for volume effects to contribute to the rate enhancement. Solvent association energies are evaluated at the DLNPO-CCSD(T) level. Specific solvent interactions are explored through atomic partial charge, molecular orbital and bond critical point analysis, as well as via non-colvalent interaction (NCI) plots, electrostatic potential (ESP) differences and density difference Δρ(r) plots. We find that the cation and anion together form an extensive van der Waals pocket in-which the transition state (TS) sits. Electron density within the TS is anisotropically polarised via a 'push-pull' effect due to the dual cation-anion nature of the IL, stabilising the TS relative to benzene. We also provide experimental evidence that these effects are generalisable to other ILs. Overall, our aim is to provide a deeper moleuclar level understanding of the impact of ILs on non-polar reactions.

4.
Sci Rep ; 14(1): 1017, 2024 01 10.
Article in English | MEDLINE | ID: mdl-38200032

ABSTRACT

Plant-based product replacements are gaining popularity. However, the long-term health implications remain poorly understood, and available methods, though accurate, are expensive and burdensome, impeding the study of sufficiently large cohorts. To identify dietary transitions over time, we examine anonymised loyalty-card shopping records from Co-op Food, UK. We focus on 10,626 frequent customers who directly replaced milk with alternative milk. We then use product nutritional information to estimate weekly nutrient intake before and after the transition. 83% who converted to alternative milk saw a fall in iodine (44%), calcium (30%) and vitamin B12 (39%) consumption, with 57% reducing iodine purchase by more than 50%. The decline is even higher for those switching dairy and meat products. Our findings suggest that dietary transitions - such as replacing milk with alternative milk - could lead to nutritional deficiencies, notably iodine, which, if not addressed, may represent a significant public health concern, particularly in countries which do not mandate salt iodisation.


Subject(s)
Iodine , Magnoliopsida , Malnutrition , Meat Products , Diet/adverse effects , Eating
5.
One Health Outlook ; 5(1): 19, 2023 Dec 18.
Article in English | MEDLINE | ID: mdl-38111066

ABSTRACT

BACKGROUND: Jeilongvirus was proposed as a new genus within the Paramyxoviridae in 2018. The advancement in metagenomic approaches has encouraged multiple reports of Jeilongvirus detection following the initial species discovery, enriching species diversity and host range within the genus. However, Jeilongvirus remains understudied in Singapore, where interfaces between humans and small mammals are plentiful. METHODS: Here, we utilized metagenomic sequencing for the exploration of viral diversity in small mammal tissues. Upon discovery of Jeilongvirus, molecular screening and full genome sequencing was conducted, with the data used to conduct statistical modelling and phylogenetic analysis. RESULTS: We report the presence of Jeilongvirus in four species of Singapore wild small mammals, detected in their spleen and kidney. We show that full genomes of three Singapore Jeilongvirus encode for eight ORFs including the small hydrophobic and transmembrane proteins. All generated genomes cluster phylogenetically within the small mammal subclade, but share low genetic similarity with representative Jeilongvirus species. Statistical modelling showed no spatial or temporal patterns and differences among species, life history traits and habitat types. CONCLUSIONS: This study serves as a basis for understanding dynamics between Jeilongvirus and small mammal hosts in Singapore by displaying the virus generalist nature. In addition, the initial detection can help to invoke improved routine surveillance and detection of circulating pathogens in synanthropic hosts.

6.
Cell Genom ; 3(12): 100443, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38116115

ABSTRACT

Genomic sequencing has emerged as a powerful tool to enhance early pathogen detection and characterization with implications for public health and clinical decision making. Although widely available in developed countries, the application of pathogen genomics among low-resource, high-disease burden settings remains at an early stage. In these contexts, tailored approaches for integrating pathogen genomics within infectious disease control programs will be essential to optimize cost efficiency and public health impact. We propose a framework for embedding pathogen genomics within national surveillance plans across a spectrum of surveillance and laboratory capacities. We adopt a public health approach to genomics and examine its application to high-priority diseases relevant in resource-limited settings. For each grouping, we assess the value proposition for genomics to inform public health and clinical decision-making, alongside its contribution toward research and development of novel diagnostics, therapeutics, and vaccines.

7.
Org Lett ; 25(51): 9243-9248, 2023 12 29.
Article in English | MEDLINE | ID: mdl-38155597

ABSTRACT

In a 2016 screen of natural product extracts, a new family of natural products, the cahuitamycins, was discovered and found to inhibit biofilm formation in the human pathogen Acinetobacter baumannii. The proposed molecular structures contained an unusual piperazic acid residue, which piqued interest related to their structure/function and biosynthesis. Herein we disclose the first total synthesis of the proposed structure of cahuitamycin A in a 12-step longest linear sequence and 18% overall yield. Comparison of spectral and biological data of the authentic natural product and synthetic compound revealed inconsistentancies with the isolated metabolite. We therefore executed the diverted total synthesis of three isomeric compounds, which were also found to be disparate from the isolated natural product. This work sets the stage for future synthetic and biochemical investigations of an important class of natural products.


Subject(s)
Acinetobacter baumannii , Biological Products , Humans , Biological Products/chemistry , Molecular Structure , Isomerism , Stereoisomerism
8.
Nat Commun ; 14(1): 7258, 2023 Nov 21.
Article in English | MEDLINE | ID: mdl-37990023

ABSTRACT

The COVID-19 pandemic led to unparalleled pressure on healthcare services. Improved healthcare planning in relation to diseases affecting the respiratory system has consequently become a key concern. We investigated the value of integrating sales of non-prescription medications commonly bought for managing respiratory symptoms, to improve forecasting of weekly registered deaths from respiratory disease at local levels across England, by using over 2 billion transactions logged by a UK high street retailer from March 2016 to March 2020. We report the results from the novel AI (Artificial Intelligence) explainability variable importance tool Model Class Reliance implemented on the PADRUS model (Prediction of Amount of Deaths by Respiratory disease Using Sales). PADRUS is a machine learning model optimised to predict registered deaths from respiratory disease in 314 local authority areas across England through the integration of shopping sales data and focused on purchases of non-prescription medications. We found strong evidence that models incorporating sales data significantly out-perform other models that solely use variables traditionally associated with respiratory disease (e.g. sociodemographics and weather data). Accuracy gains are highest (increases in R2 (coefficient of determination) between 0.09 to 0.11) in periods of maximum risk to the general public. Results demonstrate the potential to utilise sales data to monitor population health with information at a high level of geographic granularity.


Subject(s)
COVID-19 , Respiration Disorders , Respiratory Tract Diseases , Humans , Pandemics , Artificial Intelligence , COVID-19/epidemiology , Forecasting
9.
Emerg Microbes Infect ; 12(2): 2256416, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37672505

ABSTRACT

The emergence of novel betacoronaviruses has posed significant financial and human health burdens, necessitating the development of appropriate tools to combat future outbreaks. In this study, we have characterized a human cell line, IGROV-1, as a robust tool to detect, propagate, and titrate betacoronaviruses SARS-CoV-2 and HCoV-OC43. IGROV-1 cells can be used for serological assays, antiviral drug testing, and isolating SARS-CoV-2 variants from patient samples. Using time-course transcriptomics, we confirmed that IGROV-1 cells exhibit a robust innate immune response upon SARS-CoV-2 infection, recapitulating the response previously observed in primary human nasal epithelial cells. We performed genome-wide CRISPR knockout genetic screens in IGROV-1 cells and identified Aryl hydrocarbon receptor (AHR) as a critical host dependency factor for both SARS-CoV-2 and HCoV-OC43. Using DiMNF, a small molecule inhibitor of AHR, we observed that the drug selectively inhibits HCoV-OC43 infection but not SARS-CoV-2. Transcriptomic analysis in primary normal human bronchial epithelial cells revealed that DiMNF blocks HCoV-OC43 infection via basal activation of innate immune responses. Our findings highlight the potential of IGROV-1 cells as a valuable diagnostic and research tool to combat betacoronavirus diseases.


Subject(s)
COVID-19 , Coronavirus OC43, Human , Humans , Coronavirus OC43, Human/genetics , SARS-CoV-2 , Receptors, Aryl Hydrocarbon/genetics , Cell Line
10.
Acta Trop ; 246: 106992, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37543183

ABSTRACT

The Asian rodent tick (Ixodes granulatus) occurs throughout much of Asia, it frequently bites humans, and zoonotic pathogens, such as Borrelia burgdorferi (sensu lato) and Rickettsia honei, have been detected within it. Unfortunately, the ecology of I. granulatus remains poorly known, including drivers of its abundance and the interaction ecology with its sylvatic hosts. To elucidate the ecology of this medically important species, the habitat preferences of I. granulatus were assessed in Singapore and Malaysia. Ixodes granulatus showed strong associations with old forest habitats, though across different age classes of old forest there was limited variation in abundance. Ixodes granulatus was absent from other habitats including young forest, scrubland, and parks/gardens. Within its sylvatic rodent hosts, a range of factors were found to be statistically significant predictors of I. granulatus load and/or infestation risk, including sex and body condition index. Male rodents were significantly more likely to be infested and to have higher loads than females, similarly, animals with a lower body condition index were significantly more likely to be infested. Proactive public health efforts targeted at preventing bites by this tick should carefully consider its ecology to minimise ecological overlap between humans and I. granulatus.


Subject(s)
Ixodes , Ixodidae , Humans , Animals , Female , Male , Ixodes/microbiology , Rodentia , Seasons , Ecosystem , Malaysia
11.
Proc Natl Acad Sci U S A ; 120(33): e2301926120, 2023 08 15.
Article in English | MEDLINE | ID: mdl-37552753

ABSTRACT

Swine are a primary source for the emergence of pandemic influenza A viruses. The intensification of swine production, along with global trade, has amplified the transmission and zoonotic risk of swine influenza A virus (swIAV). Effective surveillance is essential to uncover emerging virus strains; however gaps remain in our understanding of the swIAV genomic landscape in Southeast Asia. More than 4,000 nasal swabs were collected from pigs in Cambodia, yielding 72 IAV-positive samples by RT-qPCR and 45 genomic sequences. We unmasked the cocirculation of multiple lineages of genetically diverse swIAV of pandemic concern. Genomic analyses revealed a novel European avian-like H1N2 swIAV reassortant variant with North American triple reassortant internal genes, that emerged approximately seven years before its first detection in pigs in 2021. Using phylogeographic reconstruction, we identified south central China as the dominant source of swine viruses disseminated to other regions in China and Southeast Asia. We also identified nine distinct swIAV lineages in Cambodia, which diverged from their closest ancestors between two and 15 B.P., indicating significant undetected diversity in the region, including reverse zoonoses of human H1N1/2009 pandemic and H3N2 viruses. A similar period of cryptic circulation of swIAVs occurred in the decades before the H1N1/2009 pandemic. The hidden diversity of swIAV observed here further emphasizes the complex underlying evolutionary processes present in this region, reinforcing the importance of genomic surveillance at the human-swine interface for early warning of disease emergence to avoid future pandemics.


Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza A virus , Influenza, Human , Orthomyxoviridae Infections , Swine Diseases , Swine , Animals , Humans , Influenza A Virus, H3N2 Subtype/genetics , Influenza A Virus, H1N1 Subtype/genetics , Reassortant Viruses/genetics , Orthomyxoviridae Infections/epidemiology , Orthomyxoviridae Infections/veterinary , Influenza, Human/epidemiology , Influenza A virus/genetics , Genomics , Phylogeny , Cambodia/epidemiology , Swine Diseases/epidemiology
12.
J Org Chem ; 88(13): 9565-9568, 2023 Jul 07.
Article in English | MEDLINE | ID: mdl-37319431

ABSTRACT

A new visible-light-driven method for the carboxylation of (hetero)aryl/vinyl bromides has been developed using catalytic 4CzIPN, nickel, phenyl triflimide, and sodium formate as a carboxylation agent. Interestingly, we found catalytic phenyl triflimide plays an essential role in promoting the reaction. While many C(sp2) carboxylation reactions require harsh reagents or gaseous carbon dioxide, we demonstrate the mild and facile construction of carboxylic acids from readily available starting materials.


Subject(s)
Bromides , Nickel , Formates , Catalysis
13.
One Health ; 16: 100529, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37363265

ABSTRACT

Orthonairovirus is a genus of viruses in the family Nairoviridae, order Bunyavirales, with a segmented circular RNA genome. They typically infect birds and mammals and are primarily transmitted by ectoparasites such as ticks. Four of nine Orthonairovirus genogroups can infect humans, with Crimean-Congo hemorrhagic fever virus infections displaying case fatality rates up to 40%. Here, we discover and describe a novel Orthonairovirus as Cencurut virus (CENV). CENV was detected in 34 of 37 Asian house shrews (Suncus murinus) sampled in Singapore and in a nymphal Amblyomma helvolum tick collected from an infected shrew. Pairwise comparison of CENV S, M, and L segments had 95.0 to 100% nucleotide and 97.5 to 100% amino acid homology within CENV genomes, suggesting a diverse viral population. Phylogenetic analysis of the individual gene segments showed that CENV is related to Erve, Lamgora, Lamusara, and Thiafora viruses, with only 49.0 to 58.2% nucleotide and 41.7 to 61.1% amino acid homology, which has previously been detected in other shrew species from France, Gabon, and Senegal respectively. The high detection frequency suggests that CENV is endemic among S. murinus populations in Singapore. The discovery of CENV, from a virus family with known zoonotic potential, underlines the importance of surveillance of synanthropic small mammals that are widely distributed across Southeast Asia.

14.
Microbiol Spectr ; 11(3): e0348322, 2023 06 15.
Article in English | MEDLINE | ID: mdl-37199653

ABSTRACT

Bats are the reservoir for numerous human pathogens, including coronaviruses. Despite many coronaviruses having descended from bat ancestors, little is known about virus-host interactions and broader evolutionary history involving bats. Studies have largely focused on the zoonotic potential of coronaviruses with few infection experiments conducted in bat cells. To determine genetic changes derived from replication in bat cells and possibly identify potential novel evolutionary pathways for zoonotic virus emergence, we serially passaged six human 229E isolates in a newly established Rhinolophus lepidus (horseshoe bat) kidney cell line. Here, we observed extensive deletions within the spike and open reading frame 4 (ORF4) genes of five 229E viruses after passaging in bat cells. As a result, spike protein expression and infectivity of human cells was lost in 5 of 6 viruses, but the capability to infect bat cells was maintained. Only viruses that expressed the spike protein could be neutralized by 229E spike-specific antibodies in human cells, whereas there was no neutralizing effect on viruses that did not express the spike protein inoculated on bat cells. However, one isolate acquired an early stop codon, abrogating spike expression but maintaining infection in bat cells. After passaging this isolate in human cells, spike expression was restored due to acquisition of nucleotide insertions among virus subpopulations. Spike-independent infection of human coronavirus 229E may provide an alternative mechanism for viral maintenance in bats that does not rely on the compatibility of viral surface proteins and known cellular entry receptors. IMPORTANCE Many viruses, including coronaviruses, originated from bats. Yet, we know little about how these viruses switch between hosts and enter human populations. Coronaviruses have succeeded in establishing in humans at least five times, including endemic coronaviruses and the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In an approach to identify requirements for host switches, we established a bat cell line and adapted human coronavirus 229E viruses by serial passage. The resulting viruses lost their spike protein but maintained the ability to infect bat cells, but not human cells. Maintenance of 229E viruses in bat cells appears to be independent of a canonical spike receptor match, which in turn might facilitate cross-species transmission in bats.


Subject(s)
COVID-19 , Chiroptera , Coronavirus 229E, Human , Animals , Humans , Phylogeny , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , SARS-CoV-2/metabolism
15.
PLoS One ; 18(5): e0285561, 2023.
Article in English | MEDLINE | ID: mdl-37196045

ABSTRACT

Young children are at increased risk of severe illness from influenza and pneumococcal infections. The World Health Organization (WHO) recommends vaccination with influenza and pneumococcal conjugate vaccine (PCV). However, in Singapore, vaccine uptake remains suboptimal relative to other routine childhood immunisations. Limited information exists regarding determinants of influenza and pneumococcal vaccine uptake in children. We estimated vaccine uptake and investigated factors associated with influenza and pneumococcal vaccination status by age group using data from a cohort study on acute respiratory infections in children attending preschools in Singapore. We recruited children aged two to six years at 24 participating preschools from June 2017 to July 2018. We determined the proportion of children immunised with influenza vaccine and PCV, and investigated socio-demographic factors associated with vaccine uptake using logistic regression models. Among 505 children, 77.5% were of Chinese ethnicity, and 53.1% were male. History of influenza vaccination was 27.5% of which 11.7% had been vaccinated within the past 12 months. In multivariable analyses, factors associated with influenza vaccine uptake were 'children living in landed property' (aOR = 2.25, 95% CI [1.07-4.67]) and 'history of hospitalisation due to cough' (aOR = 1.85, 95% CI [1.00-3.36]). Nearly three-quarters of participants (70.7% 95%CI: [66.6-74.5]) reported prior PCV vaccination. PCV uptake was higher for younger children. 'Higher parental education' (OR = 2.83, 95% CI [1.51,5.32]), 'household income' (OR = 1.26, 95% CI [1.08,1.48]) and 'smokers in household' (OR = 0.48, 95% CI [0.31,0.74]) were significantly associated with PCV uptake in univariable analyses. Only 'smokers in household' remained significantly associated with PCV uptake (aOR = 0.55, 95% CI [0.33,0.91]) in the adjusted model. Our results indicate that episodes of severe respiratory illness are a cue to influenza vaccination suggesting that doctors are more likely to recommend influenza vaccines to high-risk children. For PCV, our findings suggest overall greater awareness and education on the benefit of PCV vaccination is required.


Subject(s)
Influenza Vaccines , Influenza, Human , Pneumococcal Infections , Humans , Male , Child, Preschool , Infant , Child , Female , Influenza, Human/prevention & control , Pneumococcal Vaccines , Cohort Studies , Singapore/epidemiology , Pneumococcal Infections/prevention & control , Vaccines, Conjugate , Vaccination
16.
Viruses ; 15(3)2023 02 28.
Article in English | MEDLINE | ID: mdl-36992368

ABSTRACT

The importance of genomic surveillance on emerging diseases continues to be highlighted with the ongoing SARS-CoV-2 pandemic. Here, we present an analysis of a new bat-borne mumps virus (MuV) in a captive colony of lesser dawn bats (Eonycteris spelaea). This report describes an investigation of MuV-specific data originally collected as part of a longitudinal virome study of apparently healthy, captive lesser dawn bats in Southeast Asia (BioProject ID PRJNA561193) which was the first report of a MuV-like virus, named dawn bat paramyxovirus (DbPV), in bats outside of Africa. More in-depth analysis of these original RNA sequences in the current report reveals that the new DbPV genome shares only 86% amino acid identity with the RNA-dependent RNA polymerase of its closest relative, the African bat-borne mumps virus (AbMuV). While there is no obvious immediate cause for concern, it is important to continue investigating and monitoring bat-borne MuVs to determine the risk of human infection.


Subject(s)
COVID-19 , Chiroptera , Animals , Humans , Mumps virus/genetics , Phylogeny , SARS-CoV-2 , Genomics , Asia, Southeastern/epidemiology , Paramyxoviridae/genetics
17.
Virus Evol ; 9(1): veac121, 2023.
Article in English | MEDLINE | ID: mdl-36654682

ABSTRACT

The first case of coronavirus disease 2019 (COVID-19) in Cambodia was confirmed on 27 January 2020 in a traveller from Wuhan. Cambodia subsequently implemented strict travel restrictions, and although intermittent cases were reported during the first year of the COVID-19 pandemic, no apparent widespread community transmission was detected. Investigating the routes of severe acute respiratory coronavirus 2 (SARS-CoV-2) introduction into the country was critical for evaluating the implementation of public health interventions and assessing the effectiveness of social control measures. Genomic sequencing technologies have enabled rapid detection and monitoring of emerging variants of SARS-CoV-2. Here, we detected 478 confirmed COVID-19 cases in Cambodia between 27 January 2020 and 14 February 2021, 81.3 per cent in imported cases. Among them, fifty-four SARS-CoV-2 genomes were sequenced and analysed along with representative global lineages. Despite the low number of confirmed cases, we found a high diversity of Cambodian viruses that belonged to at least seventeen distinct PANGO lineages. Phylogenetic inference of SARS-CoV-2 revealed that the genetic diversity of Cambodian viruses resulted from multiple independent introductions from diverse regions, predominantly, Eastern Asia, Europe, and Southeast Asia. Most cases were quickly isolated, limiting community spread, although there was an A.23.1 variant cluster in Phnom Penh in November 2020 that resulted in a small-scale local transmission. The overall low incidence of COVID-19 infections suggests that Cambodia's early containment strategies, including travel restrictions, aggressive testing and strict quarantine measures, were effective in preventing large community outbreaks of COVID-19.

18.
Transbound Emerg Dis ; 69(6): 3917-3925, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36382687

ABSTRACT

Bats are important reservoirs for alpha- and beta-coronaviruses. Coronaviruses (CoV) have been detected in pteropodid bats from several Southeast Asian countries, but little is known about coronaviruses in the Indonesian archipelago in proportion to its mammalian biodiversity. In this study, we screened pooled faecal samples from the Indonesian colonies of Pteropus vampyrus with unbiased next-generation sequencing. Bat CoVs related to Rousettus leschenaultii CoV HKU9 and Eidolon helvum CoV were detected. The 121 faecal samples were further screened using a conventional hemi-nested pan-coronavirus PCR assay. Three positive samples were successfully sequenced, and phylogenetic reconstruction revealed the presence of alpha- and beta-coronaviruses. CoVs belonging to the subgenera Nobecovirus, Decacovirus and Pedacovirus were detected in a single P. vampyrus roost. This study expands current knowledge of coronavirus diversity in Indonesian flying foxes, highlighting the need for longitudinal surveillance of colonies as continuing urbanization and deforestation heighten the risk of spillover events.


Subject(s)
Chiroptera , Coronavirus Infections , Coronavirus , Animals , Coronavirus/genetics , Indonesia/epidemiology , Phylogeny , Coronavirus Infections/veterinary
19.
PLoS Pathog ; 18(8): e1010763, 2022 08.
Article in English | MEDLINE | ID: mdl-35939522

ABSTRACT

Transmembrane Protein 41B (TMEM41B) and Vacuole Membrane Protein 1 (VMP1) are two ER-associated lipid scramblases that play a role in autophagosome formation and cellular lipid metabolism. TMEM41B is also a recently validated host factor required by flaviviruses and coronaviruses. However, the exact underlying mechanism of TMEM41B in promoting viral infections remains an open question. Here, we validated that both TMEM41B and VMP1 are essential host dependency factors for all four serotypes of dengue virus (DENV) and human coronavirus OC43 (HCoV-OC43), but not chikungunya virus (CHIKV). While HCoV-OC43 failed to replicate entirely in both TMEM41B- and VMP1-deficient cells, we detected diminished levels of DENV infections in these cell lines, which were accompanied by upregulation of the innate immune dsRNA sensors, RIG-I and MDA5. Nonetheless, this upregulation did not correspondingly induce the downstream effector TBK1 activation and Interferon-beta expression. Despite low levels of DENV replication, classical DENV replication organelles were undetectable in the infected TMEM41B-deficient cells, suggesting that the upregulation of the dsRNA sensors is likely a consequence of aberrant viral replication rather than a causal factor for reduced DENV infection. Intriguingly, we uncovered that the inhibitory effect of TMEM41B deficiency on DENV replication, but not HCoV-OC43, can be partially reversed using exogenous fatty acid supplements. In contrast, VMP1 deficiency cannot be rescued using the metabolite treatment. In line with the observed phenotypes, we found that both TMEM41B- and VMP1-deficient cells harbor higher levels of compromised mitochondria, especially in VMP1 deficiency which results in severe dysregulations of mitochondrial beta-oxidation. Using a metabolomic profiling approach, we revealed distinctive global dysregulations of the cellular metabolome, particularly lipidome, in TMEM41B- and VMP1-deficient cells. Our findings highlight a central role for TMEM41B and VMP1 in modulating multiple cellular pathways, including lipid mobilization, mitochondrial beta-oxidation, and global metabolic regulations, to facilitate the replication of flaviviruses and coronaviruses.


Subject(s)
Coronavirus Infections , Coronavirus , Dengue , Energy Metabolism , Humans , Lipids , Membrane Proteins/genetics , Virus Replication
20.
Microbiol Spectr ; 10(3): e0044922, 2022 06 29.
Article in English | MEDLINE | ID: mdl-35638834

ABSTRACT

Bats are considered the natural reservoir of numerous emerging viruses such as severe acute respiratory syndrome coronaviruses (SARS-CoVs). There is a need for immortalized bat cell lines to culture and investigate the pathogenicity, replication kinetics, and evolution of emerging coronaviruses. We illustrate the susceptibility and permissiveness of a spontaneously immortalized kidney cell line (Rhileki) from Blyth's horseshoe bat (R. lepidus) to SARS-CoV-2 virus, including clinical isolates, suggesting a possible virus-host relationship. We were able to observe limited SARS-CoV-2 replication in Rhileki cells compared with simian VeroE6 cells. Slower viral replication in Rhileki cells was indicated by higher ct values (RT-PCR) at later time points of the viral culture and smaller foci (foci forming assay) compared with those of VeroE6 cells. With this study we demonstrate that SARS-CoV-2 replication is not restricted to R. sinicus and could include more Rhinolophus species. The establishment of a continuous Rhinolophus lepidus kidney cell line allows further characterization of SARS-CoV-2 replication in Rhinolophus bat cells, as well as isolation attempts of other bat-borne viruses. IMPORTANCE The current COVID-19 pandemic demonstrates the significance of bats as reservoirs for severe viral diseases. However, as bats are difficult to establish as animal models, bat cell lines can be an important proxy for the investigation of bat-virus interactions and the isolation of bat-borne viruses. This study demonstrates the susceptibility and permissiveness of a continuous kidney bat cell line to SARS-CoV-2. This does not implicate the bat species Rhinolophus lepidus, where these cells originate from, as a potential reservoir, but emphasizes the usefulness of this cell line for further characterization of SARS-CoV-2. This can lead to a better understanding of emerging viruses that could cause significant disease in humans and domestic animals.


Subject(s)
COVID-19 , Chiroptera , Animals , Humans , Kidney , Pandemics , Phylogeny , SARS-CoV-2
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