Evaluation of an RBD-nucleocapsid fusion protein as a booster candidate for COVID-19 vaccine.

Despite successful vaccines and updates, constant mutations of SARS-CoV-2 makes necessary the search for new vaccines. We generated a chimeric protein that comprises the receptor-binding domain from spike and the nucleocapsid antigens (SpiN) from SARS-CoV-2. Once SpiN elicits a protective immune response in rodents, here we show that convalescent and previously vaccinated individuals respond to SpiN. CD4+ and CD8+ T cells from these individuals produced greater amounts of IFN-γ when stimulated with SpiN, compared to SARS-CoV-2 antigens. Also, B cells from these individuals were able to secrete antibodies that recognize SpiN. When administered as a boost dose in mice previously immunized with CoronaVac, ChAdOx1-S or BNT162b2, SpiN was able to induce a greater or equivalent immune response to homologous prime/boost. Our data reveal the ability of SpiN to induce cellular and humoral responses in vaccinated human donors, rendering it a promising candidate.

Immunosuppression-induced Zika virus reactivation causes brain inflammation and behavioral deficits in mice.

Zika virus (ZIKV) is a neurotropic flavivirus that can persist in several tissues. The late consequences of ZIKV persistence and whether new rounds of active replication can occur, remain unaddressed. Here, we investigated whether neonatally ZIKV-infected mice are susceptible to viral reactivation in adulthood. We found that when ZIKV-infected mice are treated with immunosuppressant drugs, they present increased susceptibility to chemically induced seizures. Levels of subgenomic flavivirus RNAs (sfRNAs) were increased, relative to the amounts of genomic RNAs, in the brains of mice following immunosuppression and were associated with changes in cytokine expression. We investigated the impact of immunosuppression on the testicles and found that ZIKV genomic RNA levels are increased in mice following immunosuppression, which also caused significant testicular damage. These findings suggest that ZIKV can establish new rounds of active replication long after acute stages of disease, so exposed patients should be monitored to ensure complete viral eradication.

Herpesviruses in migrating procellariforms, northeastern Brazil.

Seabirds are one of the most threatened avian groups. Viruses, including herpesvirus, represent considerable threats to marine avifauna. Herein, our goal was to survey herpesvirus in Procellariiformes that stranded in Brazil between June and July 2021. We analyzed 12 Cory's shearwaters (Calonectris borealis), two Great Shearwaters (Ardenna gravis, syn. Puffinus gravis) and one Yellow-nosed Albatross (Thalassarche chlororynchos) found in an unusual mortality event in Bahía state, northeastern Brazil. After necropsy, selected tissue samples were tested for herpesvirus using a broad-range nested PCR. Overall, 20% (3/15) of the birds were herpesvirus-positive, i.e., two Cory's Shearwaters and one Great Shearwater. One alphaherpesvirus sequence type was identified in each shearwater species, classified into the genus Mardivirus. This study describes two likely novel herpesviruses in shearwaters, contributing to the currently very scarce data regarding infectious agents in Procellariiformes. Further studies are necessary to evaluate the presence and characteristics of herpesvirus in Procellariiformes, and the presence (or not) of related disease in order to understand the epidemiology of this infectious agent and eventually contribute to the conservation of this endangered seabird group.

Co-Infection of SARS-CoV-2 and Klebsiella pneumoniae: A Systematic Review and Meta-Analysis.

The study aimed to assess the prevalence of COVID-19 and Klebsiella spp. coinfection across continents. Conducted following PRISMA guidelines, a systematic review utilized PubMed, Embase, SCOPUS, ScienceDirect, and Web of Science databases, searching for literature in English published from December 2019 to December 2022, using specific Health Sciences descriptors. A total of 408 records were identified, but only 50 were eligible, and of these, only 33 were included. Thirty-three references were analyzed to evaluate the correlation between COVID-19 and Klebsiella spp. infections. The tabulated data represented a sample group of 8741 coinfected patients. The findings revealed notable disparities in co-infection rates across continents. In Asia, 23% of individuals were infected with Klebsiella pneumoniae, while in Europe, the proportion of co-infected patients stood at 15%. Strikingly, on the African continent, 43% were found to be infected with Klebsiella pneumoniae, highlighting significant regional variations. Overall, the proportion of Klebsiella pneumoniae co-infections among COVID-positive individuals were determined to be 19%. Particularly concerning was the observation that 1 in 6 ICU coinfections was attributed to Klebsiella pneumoniae, indicating its substantial impact on patient outcomes and healthcare burden. The study underscores the alarming prevalence of co-infection between COVID-19 and Klebsiella pneumoniae, potentially exacerbating the clinical severity of patients and posing challenges to treatment strategies. These findings emphasize the importance of vigilant surveillance and targeted interventions to mitigate the adverse effects of bacterial coinfections in the context of the COVID-19 pandemic.

Chapare virus infection and current perspectives on dentistry.

OBJECTIVES: This narrative review addresses relevant points about Chapare virus (CHAV) entry in oral cells, CHAV transmission, and preventive strategies in dental clinical settings. It is critical in dentistry due to the frequent presence of gingival hemorrhage occurred in CHAV-infected patients. MATERIALS AND METHODS: Studies related to CHAV were searched in MEDLINE/PubMed, Scopus, EMBASE, and Web-of-Science databases without language restriction or year of publication. RESULTS: Recently, the PAHO/WHO and CDC indicate a presence of human-to-human transmission of CHAV associated with direct contact with saliva, blood, or urine, and also through droplets or aerosols created in healthcare procedures. CHAV was detected in human oropharyngeal saliva and gingival bleeding was confirmed in all cases of CHAV hemorrhagic fever, including evidence of nosocomial CHAV transmission in healthcare workers. We revisited the human transferrin receptor 1 (TfR1) expression in oral, nasal, and salivary glands tissues, as well as, we firstly identified the critical residues in the pre-glycoprotein (GP) complex of CHAV that interacts with human TfR1 using cutting-edge in silico bioinformatics platforms associated with molecular dynamic analysis. CONCLUSIONS: In this multidisciplinary view, we also point out critical elements to provide perspectives on the preventive strategies for dentists and frontline healthcare workers against CHAV, and in the implementation of salivary diagnostic platforms for virus detection, which can be critical to an urgent plan to prevent human-to-human transmission based on current evidence. CLINICAL RELEVANCE: The preventive strategies in dental clinical settings are pivotal due to the aerosol-generating procedures in dentistry with infected patients or suspected cases of CHAV infection.

Valganciclovir in Infants with Hearing Loss and Clinically Inapparent Congenital Cytomegalovirus Infection: A Nonrandomized Controlled Trial.

OBJECTIVE: To assess the efficacy of valganciclovir in infants with hearing loss and clinically inapparent congenital cytomegalovirus infection (cCMV), as there is no consensus on treatment of this group. STUDY DESIGN: A nationwide, nonrandomized controlled trial, comparing 6 weeks of oral valganciclovir to no treatment in infants with cCMV, recruited after newborn hearing screening resulted in referral to an audiologist. The choice whether to treat was left to parents of subjects. Eligible subjects were full term infants aged <13 weeks with sensorineural hearing loss and diagnosed with cCMV through dried blood spot testing. The primary outcome, measured by linear and ordinal logistic regression, was change in best-ear hearing from baseline to follow-up at 18-22 months of age. RESULTS: Thirty-seven participants were included in the final analysis, of whom 25 were in the treatment group and 12 in the control group. The majority of subjects in both groups had neuroimaging abnormalities, which were mostly mild. Hearing deterioration was more likely in the control group compared with the treatment group (common OR 0.10, 95% CI 0.02-0.45, P = .003). Mean best-ear hearing deteriorated by 13.7 dB in the control group, compared with improvement of 3.3 dB in the treatment group (difference 17 dB, 95% CI 2.6 - 31.4, P = .02). CONCLUSIONS: We investigated treatment in children with hearing loss and clinically inapparent cCMV. Although our study was nonrandomized, it is the first prospective and controlled trial in this population. Valganciclovir-treated children with hearing loss and inapparent cCMV had less hearing deterioration at 18 through 22 months of age than control subjects. EUDRACT REGISTRY NUMBER: 2013-003068-30.

Novel herpesvirus in the critically endangered Galapagos pink land iguana.

Virus surveillance in wildlife is important to understanding ecosystem health, taxonomy, and evolution. Nevertheless, viruses in reptiles, and specifically in squamates, continue to be understudied. Herein, we conducted a health assessment on the critically endangered Galapagos pink land iguana (Conolophus marthae) and the vulnerable Galapagos land iguana (Conolophus subcristatus). We collected oral and/or cloacal swabs from 47 clinically healthy iguanas and tested for adenovirus (cloacal swabs, n = 47) and herpesvirus (oral swabs, n = 45) using broad-spectrum PCRs. Two out of 38 (5.3 %) Galapagos pink land iguanas tested positive for herpesvirus, while no herpesvirus was detected in all Galapagos land iguanas (n = 7). Both herpesviral sequences were identical between them and divergent (61.9 % amino acid identity) when compared to the closest herpesvirus sequences available in GenBank/EMBL/DDBJ. The genetic distance between this and other herpesviruses is consistent with its classification as a novel virus species. All iguanas were negative for adenovirus. This is the first description of a herpesvirus in iguanas of the Galapagos islands, and the first report of a potential pathogen for the iconic Galapagos pink land iguana. Further research is needed to understand the implications of this virus in the conservation and management of one of the most endangered iguana species in the world.

Airway epithelial cells and macrophages trigger IL-6-CD95/CD95L axis and mediate initial immunopathology of COVID-19.

Airway epithelial cells (AEC) infected with SARS-CoV-2 may drive the dysfunction of macrophages during COVID-19. We hypothesized that the direct interaction of AEC with macrophages mediated by CD95/CD95L or indirect interaction mediated by IL-6 signaling are key steps for the COVID-19 severe acute inflammation. The interaction of macrophages with apoptotic and infected AEC increased CD95 and CD163 expression, and induced macrophage death. Macrophages exposed to tracheal aspirate with high IL-6 levels from intubated patients with COVID-19 or to recombinant human IL-6 exhibited decreased HLA-DR expression, increased CD95 and CD163 expression and IL-1ß production. IL-6 effects on macrophages were prevented by both CD95/CD95L antagonist and by IL-6 receptor antagonist and IL-6 or CD95 deficient mice showed significant reduction of acute pulmonary inflammation post-infection. Our findings show a non-canonical CD95L-CD95 pathway that simultaneously drives both macrophage activation and dysfunction and point to CD95/CD95L axis as therapeutic target.

An ivermectin - atorvastatin combination impairs nuclear transport inhibiting dengue infection in vitro and in vivo.

Dengue virus (DENV) uses cellular nuclear transport machinery to import some proteins into the nucleus. Recently, the non-structural protein 3 (NS3) of DENV was localized in the nucleus of infected cells; however, its nuclear import mechanism is still unknown. In this study, we demonstrate that Ivermectin (IVM) inhibits the nuclear localization of NS3 through the inhibition of the Importin α/ß1 pathway. We also report that Atorvastatin (ATV) can modulate the nuclear transport of NS3 protease and NS5 polymerase of DENV-2. On the other hand, we found that IVM and ATV treatments reduce the alteration of nuclear pore complex (NPC) proteins, and an IVM+ATV combination reduced DENV infection both in vitro and in vivo. Hence, we conclude that ATV transport inhibition is an additional antiviral effect of this drug, suggesting a potential anti-DENV therapy in combination with IVM.

Oral Infection, Oral Pathology and Salivary Diagnostics of Mpox Disease: Relevance in Dentistry and OMICs Perspectives.

In this narrative review, we aim to point out the close relationship between mpox virus (MPXV) infection and the role of saliva as a diagnostic tool for mpox, considering the current molecular approach and in the perspective of OMICs application. The MPXV uses the host cell's rough endoplasmic reticulum, ribosomes, and cytoplasmic proteins to replicate its genome and synthesize virions for cellular exit. The presence of oral mucosa lesions associated with mpox infection is one of the first signs of infection; however, current diagnostic tools find it difficult to detect the virus before the rashes begin. MPXV transmission occurs through direct contact with an infected lesion and infected body fluids, including saliva, presenting a potential use of this fluid for diagnostic purposes. Currently available diagnostic tests for MPXV detection are performed either by real-time quantitative PCR (RT-qPCR) or ELISA, which presents several limitations since they are invasive tests. Despite current clinical trials with restricted sample size, MPXV DNA was detected in saliva with a sensitivity of 85%-100%. In this context, the application of transcriptomics, metabolomics, lipidomics, or proteomics analyses coupled with saliva can identify novel disease biomarkers. Thus, it is important to note that the identification and quantification of salivary DNA, RNA, lipid, protein, and metabolite can provide novel non-invasive biomarkers through the use of OMICs platforms aiding in the early detection and diagnosis of MPXV infection. Untargeted mass spectrometry (MS)-based proteomics reveals that some proteins also expressed in saliva were detected with greater expression differences in blood plasma when comparing mpox patients and healthy subjects, suggesting a promising alternative to be applied in screening or diagnostic platforms for mpox salivary diagnostics coupled to OMICs.

Understanding COVID-19 progression with longitudinal peripheral blood mononuclear cell proteomics: Changes in the cellular proteome over time.

The clinical presentation of COVID-19 is highly variable, and understanding the underlying biological processes is crucial. This study utilized a proteomic analysis to investigate dysregulated processes in the peripheral blood mononuclear cells of patients with COVID-19 compared to healthy volunteers. Samples were collected at different stages of the disease, including hospital admission, after 7 days of hospitalization, and 30 days after discharge. Metabolic pathway alterations and increased abundance of neutrophil-related proteins were observed in patients. Patients progressing to critical illness had significantly low-abundance proteins in the pentose phosphate and glycolysis pathways compared with those presenting clinical recovery. Important biological processes, such as fatty acid concentration and glucose metabolism disorder, remained altered even after 30 days of hospital discharge. Temporal proteomic changes revealed distinct pathways in critically ill and non-critically ill patients. Our study emphasizes the significance of longitudinal cellular proteomic studies in identifying disease progression-related pathways and persistent protein changes post-hospitalization.

Oligosymptomatic long-term carriers of SARS-CoV-2 display impaired innate resistance but increased high-affinity anti-spike antibodies.

The vast spectrum of clinical features of COVID-19 keeps challenging scientists and clinicians. Low resistance to infection might result in long-term viral persistence, but the underlying mechanisms remain unclear. Here, we studied the immune response of immunocompetent COVID-19 patients with prolonged SARS-CoV-2 infection by immunophenotyping, cytokine and serological analysis. Despite viral loads and symptoms comparable to regular mildly symptomatic patients, long-term carriers displayed weaker systemic IFN-I responses and fewer circulating pDCs and NK cells at disease onset. Type 1 cytokines remained low, while type-3 cytokines were in turn enhanced. Of interest, we observed no defects in antigen-specific cytotoxic T cell responses, and circulating antibodies displayed higher affinity against different variants of SARS-CoV-2 Spike protein in these patients. The identification of distinct immune responses in long-term carriers adds up to our understanding of essential host protective mechanisms to ensure tissue damage control despite prolonged viral infection.

Intracellular peptides in SARS-CoV-2-infected patients.

Intracellular peptides (InPeps) generated by the orchestrated action of the proteasome and intracellular peptidases have biological and pharmacological significance. Here, human plasma relative concentration of specific InPeps was compared between 175 patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and 45 SARS-CoV-2 non-infected patients; 2,466 unique peptides were identified, of which 67% were InPeps. The results revealed differences of a specific group of peptides in human plasma comparing non-infected individuals to patients infected by SARS-CoV-2, following the results of the semi-quantitative analyses by isotope-labeled electrospray mass spectrometry. The protein-protein interactions networks enriched pathways, drawn by genes encoding the proteins from which the peptides originated, revealed the presence of the coronavirus disease/COVID-19 network solely in the group of patients fatally infected by SARS-CoV-2. Thus, modulation of the relative plasma levels of specific InPeps could be employed as a predictive tool for disease outcome.

Critical disease related to SARS-CoV-2 infection in children from the Amazon region: an observational study.

This is a multicentre prospective cohort including critically ill children and adolescents, with confirmed critical disease related to SARS-CoV-2, admitted to three tertiary paediatric intensive care units in the Brazilian Amazon, between April 2020 and July 2022. 208 patients were included (median age was 3.5 years). The majority had malnutrition (62%) and comorbidities (60.6%). Mechanical ventilation support, cardiogenic shock and acute respiratory distress syndrome occurred in 47%, 30% and 34.1% of patients, respectively. There were 37 (18%) deaths. A poor outcome of severe COVID-19 and multisystem inflammatory syndrome in children was observed in children and adolescents from the Brazilian Amazon.

Characterizing the vector competence of Aphis gossypii, Myzus persicae and Aphis craccivora (Hemiptera: Aphididae) to transmit cotton leafroll dwarf virus to cotton in the United States.

Cotton leafroll dwarf virus (CLRDV) is a yield-limiting, aphid-transmitted virus that was identified in cotton, Gossypium hirsutum L., in the United States of America in 2017. CLRDV is currently classified in the genus Polerovirus, family Solemoviridae. Although 8 species of aphids (Hemiptera: Aphididae) are reported to infest cotton, Aphis gossypii Glover is the only known vector of CLRDV to this crop. Aphis gossypii transmits CLRDV in a persistent and nonpropagative manner, but acquisition and retention times have only been partially characterized in Brazil. The main objectives of this study were to characterize the acquisition access period, the inoculation access period, and retention times for a U.S. strain of CLRDV and A. gossypii population. A sub-objective was to test the vector competence of Myzus persicae Sulzer and Aphis craccivora Koch. In our study, A. gossypii apterous and alate morphs were able to acquire CLRDV in 30 min and 24 h, inoculate CLRDV in 45 and 15 min, and retain CLRDV for 15 and 23 days, respectively. Neither M. persicae nor A. craccivora acquired or transmitted CLRDV to cotton.

19n01, a broadly neutralizing antibody against omicron BA.1, BA.2, BA.4/5, and other SARS-CoV-2 variants of concern.

This study reports the isolation and characterization of a human monoclonal antibody (mAb) called 19n01. This mAb was isolated by using single-cell RNAseq of B cells from donors infected with the ancestral strain. This mAb possesses a potent and broad capacity to bind and neutralize all previously circulating variants of concern (VOCs), including Omicron sublineages BA.1, BA.2, and BA.4/5. The pseudovirus neutralization assay revealed robust neutralization capacity against the G614 strain, BA.1, BA.2, and BA.4/5, with inhibitory concentration (IC50) values ranging from 0.0035 to 0.0164 µg/mL. The microneutralization assay using the G614 strain and VOCs demonstrated IC50 values of 0.013-0.267 µg/mL. Biophysical and structural analysis showed that 19n01 cross-competes with ACE2 binding to the receptor-binding domain (RBD) and the kinetic parameters confirmed the high affinity against the Omicron sublineages (KD of 61 and 30 nM for BA.2 and BA.4/5, respectively). These results suggest that the 19n01 is a remarkably potent and broadly reactive mAb.

33rd Brazilian Society for Virology (SBV) 2022 Annual Meeting.

Each year, the Brazilian Society for Virology promotes a national meeting during the second semester of the year. In October 2022, the 33rd meeting took place at Arraial da Ajuda, Porto Seguro, Bahia, in-person:.this was the first in-person meeting since 2019, as the 2020 and 2021 events occurred online due to the issues imposed by COVID-19. It was a great pleasure for the whole audience to return to an in-person event, which certainly improved the interactions between the attendees in all ways. As usual, the meeting involved massive participation of undergraduate, graduate, and postdoc students, and several noteworthy international researchers were present. During five afternoons and evenings, attendees could discuss and learn about the most recent data presented by distinguished scientists from Brazil and other countries. In addition, young virology researchers from all levels could present their latest results as oral presentations and posters. The meeting covered all virology areas, with conferences and roundtables about human, veterinary, fundamental, environmental, invertebrate, and plant virology. The costs associated with attending the in-person event caused a slight reduction in the number of attendees compared to the two online events. However, even with this issue, the attendance was impressive. The meeting successfully achieved its most important goals: inspiring young and senior scientists and discussing high-quality, up-to-date virology research.

Herpesvirus, Flavivirus, and Coronavirus Surveillance in Magnificent Frigatebirds (Fregata magnificens), Alcatrazes Archipelago, Southeastern Brazil.

We surveyed the presence of herpesvirus, flavivirus, and coronavirus in 20 Magnificent Frigatebirds (Fregata magnificens) from the protected Alcatrazes Island, Alcatrazes archipelago, Brazil. One adult female was positive for herpesvirus (5% occurrence; 95% confidence interval -5.5 to 15.5), whereas none of the samples were PCR-positive for flavivirus or coronavirus. The obtained herpesvirus was highly similar to the one responsible for annual mortality of Magnificent Frigatebird chicks on Grand Connétable Island, French Guiana; however, no episodes of mass mortality have been recorded in the birds from Alcatrazes. Our findings indicate that this virus may be widespread in Magnificent Frigatebirds of the southwestern Atlantic. The observed differences in morbidity and mortality may be the result of basal immunosuppression of the birds from French Guiana related to environmental or nutritional conditions. The Alcatrazes archipelago sustains the largest frigatebird breeding colony of the southern Atlantic; future monitoring studies with larger sampling sizes are needed to further determine the epidemiologic relevance of the detected herpesviruses, as well as other viruses (e.g., flaviviruses, coronaviruses, avian influenza virus), in seabirds of Alcatrazes Island.