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1.
Clin Lab ; 70(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38469772

RESUMO

BACKGROUND: Two rapid antigen tests (RATs) for COVID-19 targeting the nucleocapsid protein of SARS-CoV-2 were compared with real-time RT-PCR as the reference method. METHODS: Ninety-six nasopharyngeal swab samples, comprising 56 positive and 40 negative samples confirmed through rRT-PCR were collected and retested to determine the reliability of the two nasopharyngeal RATs. RESULTS: The overall sensitivity and specificity of both RATs were 64.3% (95% confidence interval 50.4 - 76.6%) and 100% (95% confidence interval 91.2 - 100%), respectively. Cohen's kappa coefficient of agreement of both RATs to rRT-PCR was 0.600 (95% confidence interval 0.457 - 0.743) (p < 0.001), showing almost perfect agreement when the Ct values were less than 25 in rRT-PCR. A significant difference in Ct values between true positives and false negatives was observed (Mann-Whitney-Wilcoxon test; p < 0.001). CONCLUSIONS: Compared to rRT-PCR, RATs have fewer false negatives. In suspected COVID-19 cases, negative RAT results should be retested using either RAT or rRT-PCR.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Reprodutibilidade dos Testes , Teste para COVID-19 , Antígenos Virais , Sensibilidade e Especificidade , Nasofaringe
2.
Int J Mol Sci ; 25(5)2024 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-38474194

RESUMO

Since viruses are one of the main causes of infectious illnesses, prophylaxis is essential for efficient disease control. Vaccines play a pivotal role in mitigating the transmission of various viral infections and fortifying our defenses against them. The initial step in modern vaccine design and development involves the identification of potential vaccine targets through computational techniques. Here, using datasets of 1588 known viral immunogens and 468 viral non-immunogens, we apply machine learning algorithms to develop models for the prediction of protective immunogens of viral origin. The datasets are split into training and test sets in a 4:1 ratio. The protein structures are encoded by E-descriptors and transformed into uniform vectors by the auto- and cross-covariance methods. The most relevant descriptors are selected by the gain/ratio technique. The models generated by Random Forest, Multilayer Perceptron, and XGBoost algorithms demonstrate superior predictive performance on the test sets, surpassing predictions made by VaxiJen 2.0-an established gold standard in viral immunogenicity prediction. The key attributes determining immunogenicity in viral proteins are specific fingerprints in hydrophobicity and steric properties.


Assuntos
Algoritmos , Vacinas , Antígenos de Bactérias , Aprendizado de Máquina , Redes Neurais de Computação , Antígenos Virais
3.
Sci Rep ; 14(1): 6096, 2024 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-38480769

RESUMO

Serosurveys to monitor immunity toward COVID-19 in the population are primarily performed using an ELISA to screen samples for SARS-CoV-2 antibodies, followed by confirmation by a virus neutralization test, which is considered the Gold Standard. However, virus neutralization test may not be feasible for some laboratories because of the requirement for specific facilities and trained personnel. In an attempt to address this limitation, we evaluated three cell-free methods as potential alternatives for assessing SARS-CoV-2 seroprevalence in human population from plasma. We report the establishment of two inhibition ELISAs designed to detect anti-Spike RBD IgG antibodies and a microsphere quantitative suspension array technology assay, based on the Luminex xMAP platform, to measure the presence of antibodies against various SARS-CoV-2 antigens, including anti-RBD. These methods were also compared to a commercial chemiluminescent immunoassay designed for anti-RBD antibodies detection and to the combined ELISA + virus neutralization test strategy. These cell-free assays performed equally to estimate the percentage of positive and negative samples and could be used to determine the prevalence of SARS-CoV-2 antibodies in human population, at least in cohort with high-expected prevalence, without the use of seroneutralization assay.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , COVID-19/epidemiologia , SARS-CoV-2 , Estudos Soroepidemiológicos , Anticorpos Antivirais , Antígenos Virais , Anticorpos Neutralizantes
4.
BMC Infect Dis ; 24(1): 289, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448805

RESUMO

OBJECTIVE: The aim of this study is to determine the prevalence rates of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections among hemodialysis (HD) patients as well as to identify associated risk factors. METHODOLOGY: A multicenter cross-sectional study involved patients who had been on HD for at least three months. The study was conducted at five HD centers in Damascus, Syria from August 2019 to September 2021. HBsAg, HCV-Ab and HIV (antibody/antigen) seropositivity were identified using the third generation ELISA technique. Patients' information was extracted from their records and by face-to-face interview. Multiple logistic regression models were applied to identify risk factors associated with HBV or HCV seropositivity. The significance level was set at 5%. RESULTS: A total of 637 patients were included in the study with a mean age (SD) of 50.5 (15.6) years and 56.7% of them were men. The dialytic age ranged from one to thirty years with a mean (SD) of 6.10 (5.6) years. The prevalence of positive hepatitis B surface antigen, anti-HCV, co-infection of HBV and HCV, and anti-HIV (antibody/antigen) were 3.2%, 22.1%, 0.7%, and 0%, respectively. After controlling for co-variables, hepatitis B vaccine was the only predictor of seropositivity of HBV (OR: 0.15, 95% CI: 0.057-0.393, P < 0.001), as it significantly protected against contracting HBV. On the other hand, the dialytic age (OR: 1.42, 95% CI: 1.12-1.94, P = 0.032) and the dialysis center were significant factors affecting the prevalence of HCV. CONCLUSIONS: The prevalence of HCV and HBV infections among HD patients in Damascus, Syria has decreased remarkably compared with the results from 2001. Nevertheless, it is still considered relatively high. Thus, there is an urgent need to strengthen the prevention and control measures for viral infection transmission in HD centers in Damascus.


Assuntos
HIV-1 , Hepatite C , Masculino , Humanos , Lactente , Pré-Escolar , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Feminino , Hepacivirus , Vírus da Hepatite B , Estudos Transversais , Estudos Soroepidemiológicos , Síria/epidemiologia , Hepatite C/epidemiologia , Fatores de Risco , Antígenos Virais , Anticorpos Anti-HIV
5.
Anal Chem ; 96(11): 4495-4504, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38445954

RESUMO

The molecular detection of multiple respiratory viruses provides evidence for the rational use of drugs and effective health management. Herein, we developed and tested the clinical performance of an electrohydrodynamic-driven nanobox-on-mirror platform (E-NoM) for the parallel, accurate, and sensitive detection of four respiratory viral antigens. The E-NoM platform uses gold-silver alloy nanoboxes as the core material with the deposition of a silver layer as a shell on the core surfaces to amplify and enable a reproducible Raman signal readout that facilitates accurate detection. Additionally, the E-NoM platform employs gold microelectrode arrays as the mirror with electrohydrodynamics to manipulate the fluid flow and enhance molecular interactions for an improved biosensing response. The presence of viral antigens binds the nanobox-based core-shell nanostructure on the gold microelectrode and creates the nanocavity with extremely strong "hot spots" to benefit sensitive analysis. Significantly, in a large clinical cohort with 227 patients, the designed E-NoM platform demonstrates the capability of screening respiratory infection with achieved clinical specificity, sensitivity, and accuracy of 100.0, 96.48, and 96.91%, respectively. It is anticipated that the E-NoM platform can find a position in clinical usage for respiratory disease diagnosis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Vírus , Humanos , Nanopartículas Metálicas/química , Prata/química , Ouro/química , Antígenos Virais , Análise Espectral Raman
6.
J Appl Microbiol ; 135(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38471668

RESUMO

AIMS: Enteroviruses are significant human pathogens associated with a range of mild to severe diseases. This study aims to understand the diversity and genetic characterization of enteroviruses circulated in southwest China's border cities by using environmental surveillance. METHODS AND RESULTS: A total of 96 sewage samples were collected in three border cities and a port located in Yunnan Province, China from July 2020 to June 2022. After cell culture and VP1 sequencing, a total of 590 enterovirus isolates were identified, belonging to 21 types. All PV strains were Sabin-like with ≤6 nucleotide mutations in the VP1 coding region. Echovirus 6, echovirus 21 (a rare serotype in previous studies), and coxsackievirus B5 were the predominant serotypes, which accounted for 21.19%, 18.31%, and 13.39% of the total isolates, respectively. The prevalence of the common serotypes varied across different border cities and periods. Phylogenetic analysis revealed the presence of multiple evolutionary lineages for E21, E6, and E30, some of which formed distinct branches. CONCLUSIONS: High diversity of enteroviruses and distinct lineages of predominant serotypes circulated in southwest China's border cities.


Assuntos
Infecções por Enterovirus , Enterovirus , Humanos , Cidades , Filogenia , China/epidemiologia , Infecções por Enterovirus/epidemiologia , Enterovirus Humano B/genética , Antígenos Virais/genética , Monitoramento Ambiental/métodos
7.
Ann Clin Lab Sci ; 54(1): 126-130, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38514052

RESUMO

OBJECTIVE: We assessed the performance of the Humasis COVID-19 AgHS Test (Humasis, Korea), a novel antigen rapid diagnostic test (Ag-RDT) based on lateral flow immunoassay. METHODS: 85 SARS-CoV-2-positive and 155 SARS-CoV-2-negative nasopharyngeal swab specimens confirmed by rRT-PCR were tested using the Humasis and PBCheck Ag-RDTs. The analytical specificity of the Humasis Ag-RDT was evaluated using 27 strains of human respiratory pathogens. RESULTS: The overall sensitivity and specificity were 72.9% and 99.4% for the Humasis Ag-RDT and 64.7% and 100% for the PBCheck Ag-RDT, respectively. The sensitivity for specimens with Ct≤25 was 100% for both Ag-RDTs. The Humasis Ag-RDT showed no cross-reactivity with other respiratory pathogens. CONCLUSION: Our data suggests that the Humasis Ag-RDT can be a useful diagnostic tool for the detection of SARS-CoV-2 infection.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , Testes de Diagnóstico Rápido , SARS-CoV-2 , Comunicação , Sensibilidade e Especificidade , Antígenos Virais , Teste para COVID-19
8.
Front Immunol ; 15: 1272493, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38433846

RESUMO

Introduction: A limited subset of HIV-1 infected adult individuals typically after at least 2-3 years of chronic infection, develop broadly neutralizing antibodies (bnAbs), suggesting that highly conserved neutralizing epitopes on the HIV-1 envelope glycoprotein are difficult for B cell receptors to effectively target, during natural infection. Recent studies have shown the evolution of bnAbs in HIV-1 infected infants. Methods: We used bulk BCR sequencing (BCR-seq) to profile the B cell receptors from longitudinal samples (3 time points) collected from a rare pair of antiretroviralnaïve, HIV-1 infected pediatric monozygotic twins (AIIMS_329 and AIIMS_330) who displayed elite plasma neutralizing activity against HIV-1. Results: BCR-seq of both twins revealed convergent antibody characteristics including V-gene use, CDRH3 lengths and somatic hypermutation (SHM). Further, antibody clonotypes with genetic features similar to highly potent bnAbs isolated from adults showed ongoing development in donor AIIMS_330 but not in AIIMS_329, corroborating our earlier findings based on plasma bnAbs responses. An increase in SHM was observed in sequences of the IgA isotype from AIIMS_330. Discussion: This study suggests that children living with chronic HIV-1 can develop clonotypes of HIV-1 bnAbs against multiple envelope epitopes similar to those isolated from adults, highlighting that such B cells could be steered to elicit bnAbs responses through vaccines aimed to induce bnAbs against HIV-1 in a broad range of people including children.


Assuntos
Soropositividade para HIV , HIV-1 , Adulto , Lactente , Humanos , Criança , Anticorpos Amplamente Neutralizantes , Receptores de Antígenos de Linfócitos B/genética , Anticorpos , Antígenos Virais , Epitopos , Gêmeos Monozigóticos
9.
J Med Virol ; 96(3): e29503, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38445750

RESUMO

Enterovirus C116 (EV-C116) is a new member of the enterovirus C group which is closely associated with several infectious diseases. Although sporadic studies have detected EV-C116 in clinical samples worldwide, there is currently limited information available. In this study, two EV-C-positive fecal specimens were detected in apparently healthy children, which harbored low abundance, through meta-transcriptome sequencing. Based on the prototypes of several EV-Cs, two lineages were observed. Lineage 1 included many types that could not cause EV-like cytopathic effect in cell culture. Three genogroups of EV-C116 were divided in the maximum likelihood tree, and the two strains in this study (XZ2 and XZ113) formed two different lineages, suggesting that EV-C116 still diffuses worldwide. Obvious inter-type recombination events were observed in the XZ2 strain, with CVA22 identified as a minor donor. However, another strain (XZ113) underwent different recombination situations, highlighting the importance of recombination in the formation of EV-Cs biodiversity. The EV-C116 strains could propagate in rhabdomyosarcoma cell cultures at low titer; however, EV-like cytopathic effects were not observed. HEp-2, L20B, VERO, and 293T cell lines did not provide an appropriate environment for EV-C116 growth. These results challenge the traditional recognition of the uncultured nature of EV-C116 strains and explain the difficulty of clinical detection.


Assuntos
Infecções por Enterovirus , Enterovirus , Criança , Humanos , Enterovirus/genética , Infecções por Enterovirus/epidemiologia , China/epidemiologia , Antígenos Virais , Células HEK293
10.
J Nanobiotechnology ; 22(1): 86, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38429829

RESUMO

The human monkeypox virus (Mpox) is classified as a member of the Poxviridae family and belongs to the Orthopoxvirus genus. Mpox possesses double-stranded DNA, and there are two known genetic clades: those originating in West Africa and the Congo Basin, commonly known as Central African clades. Mpox may be treated with either the vaccinia vaccination or the therapeutics. Modifying the smallpox vaccine for treating and preventing Mpox has shown to be beneficial because of the strong link between smallpox and Mpox viruses and their categorization in the same family. Cross-protection against Mpox is effective with two Food and Drug Administration (FDA)-approved smallpox vaccines (ACAM2000 and JYNNEOSTM). However, ACAM2000 has the potential for significant adverse effects, such as cardiac issues, whereas JYNNEOS has a lower risk profile. Moreover, Mpox has managed to resurface, although with modified characteristics, due to the discontinuation and cessation of the smallpox vaccine for 40 years. The safety and efficacy of the two leading mRNA vaccines against SARS-CoV-2 and its many variants have been shown in clinical trials and subsequent data analysis. This first mRNA treatment model involves injecting patients with messenger RNA to produce target proteins and elicit an immunological response. High potency, the possibility of safe administration, low-cost manufacture, and quick development is just a few of the benefits of RNA-based vaccines that pave the way for a viable alternative to conventional vaccines. When protecting against Mpox infection, mRNA vaccines are pretty efficient and may one day replace the present whole-virus vaccines. Therefore, the purpose of this article is to provide a synopsis of the ongoing research, development, and testing of an mRNA vaccine against Mpox.


Assuntos
Vacina Antivariólica , Varíola , Estados Unidos , Humanos , Vacinas de mRNA , Vacinas contra COVID-19 , Antígenos Virais
11.
Microb Cell Fact ; 23(1): 41, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321489

RESUMO

BACKGROUND: Developing effective vaccines against SARS-CoV-2 that consider manufacturing limitations, equitable access, and acceptance is necessary for developing platforms to produce antigens that can be efficiently presented for generating neutralizing antibodies and as a model for new vaccines. RESULTS: This work presents the development of an applicable technology through the oral administration of the SARS-CoV-2 RBD antigen fused with a peptide to improve its antigenic presentation. We focused on the development and production of the recombinant receptor binding domain (RBD) produced in E. coli modified with the addition of amino acids extension designed to improve antigen presentation. The production was carried out in shake flask and bioreactor cultures, obtaining around 200 mg/L of the antigen. The peptide-fused RBD and peptide-free RBD proteins were characterized and compared using SDS-PAGE gel, high-performance chromatography, and circular dichroism. The peptide-fused RBD was formulated in an oil-in-water emulsion for oral mice immunization. The peptide-fused RBD, compared to RBD, induced robust IgG production in mice, capable of recognizing the recombinant RBD in Enzyme-linked immunosorbent assays. In addition, the peptide-fused RBD generated neutralizing antibodies in the sera of the dosed mice. The formulation showed no reactive episodes and no changes in temperature or vomiting. CONCLUSIONS: Our study demonstrated the effectiveness of the designed peptide added to the RBD to improve antigen immunostimulation by oral administration.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Humanos , Camundongos , Adjuvantes Imunológicos , Vacinas contra COVID-19 , Escherichia coli , Administração Oral , Antígenos Virais , Anticorpos Neutralizantes , Peptídeos , Anticorpos Antivirais
12.
Antiviral Res ; 223: 105824, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38309307

RESUMO

Coxsackievirus B3 (CVB3), one serotype of enteroviruses, can induce fatal myocarditis and hepatitis in neonates, but both treatment and vaccine are unavailable. Few reports tested antivirals to reduce CVB3. Several antivirals were developed against other enterovirus serotypes, but these antivirals failed in clinical trials due to side effects and drug resistance. Repurposing of clinical drugs targeting cellular factors, which enhance viral replication, may be another option. Parasite and cancer studies showed that the cellular protein kinase B (Akt) decreases interferon (IFN), apoptosis, and interleukin (IL)-6-induced STAT3 responses, which suppress CVB3 replication. Furthermore, miltefosine, the Akt inhibitor used in the clinic for parasite infections, enhances IL-6, IFN, and apoptosis responses in treated patients, suggesting that miltefosine could be the potential antiviral for CVB3. This study was therefore designated to test the antiviral effects of miltefosine against CVB3 in vitro and especially, in mice, as few studies test miltefosine in vitro, but not in vivo. In vitro results showed that miltefosine inhibited viral replication with enhanced activation of the cellular transcription factor, STAT3, which is reported to reduce CVB3 both in vitro and in mice. Notably, STAT3 knockdown abolished the anti-CVB3 activity of miltefosine in vitro. Mouse studies demonstrated that miltefosine pretreatment reduced CVB3 lethality of mice with decreased virus loads, organ damage, and apoptosis, but enhanced STAT3 activation. Miltefosine could be prophylaxis for CVB3 by targeting Akt to enhance STAT3 activation in the mechanism, which is independent of IFN responses and hardly reported in pathogen infections.


Assuntos
Infecções por Enterovirus , Fosforilcolina/análogos & derivados , Fator de Transcrição STAT3 , Humanos , Animais , Camundongos , Proteínas Proto-Oncogênicas c-akt , Apoptose , Antígenos Virais , Infecções por Enterovirus/tratamento farmacológico , Interleucina-6 , Antivirais/farmacologia
13.
J Comp Pathol ; 209: 31-35, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38350270

RESUMO

Borna disease (BD) associated with a peracute bacterial septicaemia with Escherichia coli was diagnosed in an adult female, naturally infected, free-ranging Eurasian beaver of the subspecies Castor fiber albicus, clinically characterized by weight loss, depression, weakness and gurgled peristaltic sounds. The beaver was euthanized humanely. Necropsy and light microscopy revealed a non-purulent meningoencephalitis with typical mononuclear perivascular cuffs and parenchymal infiltrates. The diagnosis of BD was confirmed by detection of viral antigen and RNA by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). The PCR product was sequenced and cluster analysis revealed a close relationship between endemic clusters in Saxony-Anhalt. This is the first report of naturally occurring BD in a free-ranging Eurasian beaver.


Assuntos
Doença de Borna , Meningoencefalite , Sepse , Feminino , Animais , Antígenos Virais , Autopsia/veterinária , Meningoencefalite/veterinária , Sepse/veterinária
14.
PLoS Pathog ; 20(2): e1012023, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38381773

RESUMO

Protein-level immunodominance patterns against Kaposi sarcoma-associated herpesvirus (KSHV), the aetiologic agent of Kaposi sarcoma (KS), have been revealed from serological probing of whole protein arrays, however, the epitopes that underlie these patterns have not been defined. We recently demonstrated the utility of phage display in high-resolution linear epitope mapping of the KSHV latency-associated nuclear antigen (LANA/ORF73). Here, a VirScan phage immunoprecipitation and sequencing approach, employing a library of 1,988 KSHV proteome-derived peptides, was used to quantify the breadth and magnitude of responses of 59 sub-Saharan African KS patients and 22 KSHV-infected asymptomatic individuals (ASY), and ultimately to support an application of machine-learning-based predictive modeling using the peptide-level responses. Comparing anti-KSHV antibody repertoire revealed that magnitude, not breadth, increased in KS. The most targeted epitopes in both KS and ASY were in the immunodominant proteins, notably, K8.129-56 and ORF65140-168, in addition to LANA. Finally, using unbiased machine-learning-based predictive models, reactivity to a subset of 25 discriminative peptides was demonstrated to successfully classify KS patients from asymptomatic individuals. Our study provides the highest resolution mapping of antigenicity across the entire KSHV proteome to date, which is vital to discern mechanisms of viral pathogenesis, to define prognostic biomarkers, and to design effective vaccine and therapeutic strategies. Future studies will investigate the diagnostic, prognostic, and therapeutic potential of the 25 discriminative peptides.


Assuntos
Síndrome de Imunodeficiência Adquirida , Infecções por Herpesviridae , Herpesvirus Humano 8 , Sarcoma de Kaposi , Humanos , Herpesvirus Humano 8/metabolismo , Proteoma/metabolismo , Antígenos Virais , Proteínas Nucleares/metabolismo , Infecções por Herpesviridae/complicações , Peptídeos/metabolismo , Epitopos/metabolismo
15.
Vaccine ; 42(7): 1630-1647, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38336561

RESUMO

Emergence of SARS-CoV-2 Omicron variant has presented a significant challenge to global health, demanding rapid development of mRNA-based vaccines. The mRNA-guided vaccine platforms offer various advantages over traditional vaccine platforms. The mRNA by nature is a short-lived molecule that guides the cells to manufacture antigenic proteins. In the present work, we have created an omicron spike antigenic protein sequence characterized by base composition analysis, modeling, and docking with the ACE-2 receptor. Further, we predicted the B-cell and T-cell epitopes followed by antigenicity, toxicity, and allergenicity. Finally, the protein was reverse translated, codon-optimized, and encoding mRNA sequence was checked for its stability by predicting the secondary structures. A comprehensive examination of in-silico data revealed 628.2 as a potent antigenic candidate that was finally used in Gemcovac®-OM, a heterologous booster mRNA vaccine for COVID-19.


Assuntos
COVID-19 , Vacinas de mRNA , Humanos , Vacinas contra COVID-19 , SARS-CoV-2/genética , COVID-19/prevenção & controle , Antígenos Virais , Epitopos de Linfócito T/genética , RNA Mensageiro , Epitopos de Linfócito B/genética , Simulação de Acoplamento Molecular
16.
Arch Virol ; 169(3): 44, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38341400

RESUMO

Foot-and-mouth disease is a highly contagious disease that affects cloven-hoofed animals. It has an important socio-economic impact on the livestock industry because it produces a drastic decrease of productivity. The disease has been successfully eradicated from some regions, including North America and Western Europe, but it is still endemic in developing countries. Agriculture plays an important role in the national economy of Vietnam, to which animal production contributes a great proportion. The concurrent circulation of foot-and-mouth disease virus (FMDV) serotypes O, A, and Asia 1 has been detected in recent years, but serotype O remains the most prevalent and is responsible for the highest numbers of outbreaks. Appropriate vaccine strain selection is an important element in the control of FMD and is necessary for the application of vaccination programs in FMD-affected regions. Here, we present updated information about the genetic and antigenic characteristics of circulating strains, collected from endemic outbreaks involving types O and A, between 2010 and 2019. Neutralizing assays showed a good in vitro match between type O strains and the monovalent O1 Campos vaccine strain. High r1 values were obtained (above 0.7) when testing a swine serum pool collected 21 days after vaccination, but the O/VTN/2/2019 strain was an exception. An EPP estimation resulted in a median neutralizing titre of about 1.65 log10, indicating that good protection could be achieved. For type A Asia SEA 97 lineage strains, acceptable individual neutralizing titres were obtained with estimated EPP values over 80% for different combinations of vaccine strains. Taking into account that the r1 value is one tool of a battery of tests that should be considered for estimating the cross-protection of a field strain against a vaccine strain, an in vivo challenge experiment was also performed, yielding a PD50 value of 8.0. The results indicate that South American strains could be potentially used for controlling outbreaks involving these lineages. This study demonstrates the importance of considering strain characteristics when choosing vaccine strains and controls.


Assuntos
Vírus da Febre Aftosa , Febre Aftosa , Vacinas Virais , Animais , Suínos , Vietnã/epidemiologia , Vacinas Virais/genética , Febre Aftosa/epidemiologia , Febre Aftosa/prevenção & controle , Antígenos Virais/genética , Sorogrupo
17.
Nat Commun ; 15(1): 1553, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378768

RESUMO

Ever-evolving SARS-CoV-2 variants of concern (VOCs) have diminished the effectiveness of therapeutic antibodies and vaccines. Developing a coronavirus vaccine that offers a greater breadth of protection against current and future VOCs would eliminate the need to reformulate COVID-19 vaccines. Here, we rationally engineer the sequence-conserved S2 subunit of the SARS-CoV-2 spike protein and characterize the resulting S2-only antigens. Structural studies demonstrate that the introduction of interprotomer disulfide bonds can lock S2 in prefusion trimers, although the apex samples a continuum of conformations between open and closed states. Immunization with prefusion-stabilized S2 constructs elicits broadly neutralizing responses against several sarbecoviruses and protects female BALB/c mice from mouse-adapted SARS-CoV-2 lethal challenge and partially protects female BALB/c mice from mouse-adapted SARS-CoV lethal challenge. These engineering and immunogenicity results should inform the development of next-generation pan-coronavirus therapeutics and vaccines.


Assuntos
COVID-19 , SARS-CoV-2 , Feminino , Animais , Humanos , Camundongos , Vacinas contra COVID-19 , COVID-19/prevenção & controle , Antígenos Virais/genética , Camundongos Endogâmicos BALB C , Glicoproteína da Espícula de Coronavírus/genética , Anticorpos Neutralizantes , Anticorpos Antivirais
18.
Viruses ; 16(2)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38399946

RESUMO

Enteroviruses (EVs) represent a major cause of viral meningitis, being responsible for nearly 1 billion infections each year worldwide. Several techniques were developed to obtain better diagnostic results of EV infections. Herein, we evaluated the efficiency of EV detection through isolation on both Rhabdomyosarcoma (RD) and Vero cell line cultures, conventional reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR. Thus, 50 cerebrospinal fluid (CSF) samples belonging to patients suspected to have viral meningitis in northern Algeria were collected, anonymously numbered from 1 to 50 and subjected to the above-mentioned techniques for EV detection. Using real-time RT-PCR, 34 CSF samples were revealed to be positive for viral origin of meningitis (68%). Thirteen of them were positive when the conventional RT-PCR was used (26%), and only three samples gave positive results when the cell culture technique was used (6%). Surprisingly, two cell culture-positive CSF samples, namely, 31 and 39, were negative using RT-PCR directly on the original samples. However, they turned to be positive when amplification was carried out on their corresponding cell culture supernatant. The cell-cultured viral isolates were then identified by sequencing their viral genome's VP1 regions. All of them were revealed to belong to the echovirus 27 strain. This investigation demonstrates that RT-PCR techniques are often more sensitive, accurate and much faster, providing reliable results within a clinically acceptable timeframe. However, viral isolation on cell cultures remains crucial to obtain enough viral load for serological tests or even to avoid the rare, but existing, false negative PCR.


Assuntos
Infecções por Enterovirus , Enterovirus , Meningite Viral , Animais , Chlorocebus aethiops , Humanos , RNA Viral/análise , Enterovirus/genética , Meningite Viral/diagnóstico , Células Vero , Antígenos Virais , Reação em Cadeia da Polimerase Via Transcriptase Reversa
19.
Sci Rep ; 14(1): 4556, 2024 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402333

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic has created a public health crisis. This study aimed to evaluate the diagnostic performance of the Panbio and STANDARD Q COVID-19 antigen rapid diagnostic tests (RDTs) against the real-time polymerase chain reaction (RT-PCR) at one of the largest hospitals in southern Ethiopia. Nasopharyngeal samples, which were collected during the pandemic from individuals suspected of COVID-19 and stored at - 70 °C, were analyzed in June and July 2022. The performance of the Panbio COVID-19 antigen tests was evaluated in 200 randomly selected nasopharyngeal samples (100 positives and 100 negatives for severe acute respiratory syndrome 2 by RT-PCR). The STANDARD Q test was evaluated using 100 positive and 50 negative samples. The respective sensitivity, specificity, positive predictive value and negative predictive values were 88%, 99%, 98.9% and 89.2% for the Panbio test and 91%, 98%, 98.9% and 84.5%, for the STANDARD Q test. The kappa values were 0.87 for the Panbio and 0.86 for the STANDARD Q test. Based on the findings presented here, the RDTs could be utilized as an alternative to conventional RT-PCR when it is challenging to diagnose COVID-19 owing to a lack of time, skilled lab personnel, or suitable equipment or electricity.


Assuntos
COVID-19 , Humanos , Reação em Cadeia da Polimerase em Tempo Real , COVID-19/diagnóstico , Etiópia , Eletricidade , Hospitais , Sensibilidade e Especificidade , Antígenos Virais , Teste para COVID-19
20.
Front Cell Infect Microbiol ; 14: 1341891, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38404292

RESUMO

Lassa virus (LASV) causes an acute multisystemic hemorrhagic fever in humans known as Lassa fever, which is endemic in several African countries. This manuscript focuses on the progression of disease in cynomolgus macaques challenged with aerosolized LASV and serially sampled for the development and progression of gross and histopathologic lesions. Gross lesions were first noted in tissues on day 6 and persisted throughout day 12. Viremia and histologic lesions were first noted on day 6 commencing with the pulmonary system and hemolymphatic system and progressing at later time points to include all systems. Immunoreactivity to LASV antigen was first observed in the lungs of one macaque on day 3 and appeared localized to macrophages with an increase at later time points to include immunoreactivity in all organ systems. Additionally, this manuscript will serve as a detailed atlas of histopathologic lesions and disease progression for comparison to other animal models of aerosolized Arenaviral disease.


Assuntos
Febre Lassa , Vírus Lassa , Humanos , Animais , Febre Lassa/patologia , Macaca fascicularis , Antígenos Virais , Viremia
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