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Experimental Biology and Medicine... 2024Bunyamwera virus (BUNV) () has been found in Sub-Saharan Africa and demonstrated recently as cocirculating with Rift Valley Fever Virus (RVFV). Little is known regarding...
Bunyamwera virus (BUNV) () has been found in Sub-Saharan Africa and demonstrated recently as cocirculating with Rift Valley Fever Virus (RVFV). Little is known regarding the breadth of transmission modalities of Bunyamwera. Given its co-occurence with RVFV, we hypothesized the transmission system of BUNV shared similarities to the RVFV system including transmission by mosquitoes and environmentally mediated transmission through fomites and environmental contamination. We exposed mosquitoes to BUNV and evaluated their ability to transmit both vertically and horizontally. Further, we investigated the potential for a novel transmission modality via environmental contamination. We found that the LSU colony of was not competent for the virus for either horizontal or vertical transmission; but, 20% of larva exposed to virus via contaminated aquatic habitat were positive. However, transstadial clearance of the virus was absolute. Finally, under simulated temperature conditions that matched peak transmission in Rwanda, we found that BUNV was stable in both whole blood and serum for up to 28 days at higher total volume in tubes at moderate quantities (10 genome copies/mL). In addition, infectiousness of these samples was demonstrated in 80% of the replicates. At lower volume samples (in plates), infectiousness was retained out to 6-8 days with a maximum infectious titer of 10 PFU/mL. Thus, the potential for contamination of the environment and/or transmission via contaminated fomites exists. Our findings have implications for biosafety and infection control, especially in the context of food animal production.
Topics: Animals; Bunyamwera virus; Aedes; Rift Valley fever virus
PubMed: 38510492
DOI: 10.3389/ebm.2024.10114 -
Science Progress 2024The common gastrointestinal commensal is a mucin-degrading bacterium that is greatly reduced in individuals consuming a high-fat diet. Increasing evidence from a...
The common gastrointestinal commensal is a mucin-degrading bacterium that is greatly reduced in individuals consuming a high-fat diet. Increasing evidence from a variety of clinical and pre-clinical studies suggests that oral supplementation with can improve metabolic health and moderate systemic inflammation. We and others have demonstrated a role for administration in protection against infectious disease and the outcome from sepsis. Very recent studies have indicated the molecular mechanisms by which may interact with the host to influence systemic immune-regulation and control of microbial pathogenesis. Here we consider recent studies which demonstrate the efficacy of this potential next-generation probiotic in animal models of Typhimurium, and as well as influenza virus and phlebovirus. The potential mechanisms by which may influence local and systemic immune responses are discussed.
Topics: Animals; Humans; Verrucomicrobia; Akkermansia; Probiotics; Communicable Diseases
PubMed: 38490164
DOI: 10.1177/00368504241231159 -
Microbiology Spectrum Apr 2024Sandfly-borne phleboviruses (SBPs), which cause sandfly fever, aseptic meningitis, encephalitis, and meningoencephalitis, are emerging pathogens of major public health...
UNLABELLED
Sandfly-borne phleboviruses (SBPs), which cause sandfly fever, aseptic meningitis, encephalitis, and meningoencephalitis, are emerging pathogens of major public health concern. Virus nucleic acid testing is essential for SBP diagnosis, especially in the early stages of infection, and for the discovery of novel SBPs. The efficacy of utilizing generic primers that target conserved nucleotide sequences for the detection of both known and novel SBPs has not been extensively evaluated. We aimed to compare and evaluate the performance of five generic primer sets, widely used to detect S- and L-segments of arthropod-borne phleboviruses and designed as singleplex ( = 3) and nested ( = 2) formats, including both well-known and recently characterized 15 Old World virus strains. Furthermore, we performed analysis to assess the detection capabilities of these generic primer sets. The initial evaluation of previously published generic primer sets for SBP detection yielded two singleplex primer sets with the potential to be adapted for use in real-time or high-throughput detection settings. Studies are ongoing to develop and further optimize a preliminary assay and test various hosts and vectors to assess their capacity to detect known and novel viruses.
IMPORTANCE
Virus nucleic acid testing is the primary diagnostic method, particularly in the early stages of illness. Virus-specific or syndromic tests are widely used for this purpose. The use of generic primers has had a considerable impact on the discovery, identification, and detection of Old World sandfly-borne phleboviruses (OWSBP). The study is significant because it is the first to carry out a comparative evaluation of all published OWSBP generic primer sets.
Topics: Animals; Phlebovirus; Psychodidae; Nucleic Acid Amplification Techniques; Nucleic Acids; Phylogeny
PubMed: 38456695
DOI: 10.1128/spectrum.03428-23 -
PLoS Neglected Tropical Diseases Mar 2024Rift Valley fever (RVF) is a mosquito-borne viral zoonosis caused by the Rift Valley fever virus (RVFV) that can infect domestic and wild animals. Although the RVFV...
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis caused by the Rift Valley fever virus (RVFV) that can infect domestic and wild animals. Although the RVFV transmission cycle has been well documented across Africa in savanna ecosystems, little is known about its transmission in tropical rainforest settings, particularly in Central Africa. We therefore conducted a survey in northeastern Gabon to assess RVFV circulation among wild and domestic animals. Among 163 wildlife samples tested using RVFV-specific RT-qPCR, four ruminants belonging to subfamily Cephalophinae were detected positive. The phylogenetic analysis revealed that the four RVFV sequences clustered together with a virus isolated in Namibia within the well-structured Egyptian clade. A cross-sectional survey conducted on sheep, goats and dogs living in villages within the same area determined the IgG RVFV-specific antibody prevalence using cELISA. Out of the 306 small ruminants tested (214 goats, 92 sheep), an overall antibody prevalence of 15.4% (95% CI [11.5-19.9]) was observed with a higher rate in goats than in sheep (20.1% versus 3.3%). RVFV-specific antibodies were detected in a single dog out of the 26 tested. Neither age, sex of domestic animals nor season was found to be significant risk factors of RVFV occurrence. Our findings highlight sylvatic circulation of RVFV for the first time in Gabon. These results stress the need to develop adequate surveillance plan measures to better control the public health threat of RVFV.
Topics: Animals; Sheep; Dogs; Rift Valley fever virus; Animals, Domestic; Animals, Wild; Gabon; Cross-Sectional Studies; Ecosystem; Phylogeny; Rift Valley Fever; Ruminants; Goats; Antibodies, Viral; Forests; Seroepidemiologic Studies
PubMed: 38427694
DOI: 10.1371/journal.pntd.0011756 -
Acta Tropica May 2024Tick-borne viruses (TBV) have gained public health relevance in recent years due to the recognition of human-associated fatal cases and the increase in tick-borne...
Tick-borne viruses (TBV) have gained public health relevance in recent years due to the recognition of human-associated fatal cases and the increase in tick-borne disease and transmission. However, many tick species have not been studied for their potential to transmit pathogenic viruses, especially those found in Latin America. To gain better understanding of the tick virome, we conducted targeted amplification using broadly-reactive consensus-degenerate pan-viral targeting viruses from the genera Flavivirus, Bandavirus, Uukuvirus, and Orthonairovirus genus. Additionally, we conducted unbiased metagenomic analyses to investigate the presence of viral RNA sequences in Amblyomma cajennense, A. patinoi and Rhipicephalus microplus ticks collected from a horse slaughter plant in Medellín, Colombia. While no viral products were detected by PCR, results of the metagenomic analyses revealed the presence of viral genomes belonging to the genera Phlebovirus, Bandavirus, and Uukuvirus, including Lihan Tick Virus (LTV), which was previously reported in Rhipicephalus microplus from Colombia. Overall, the results emphasized the enormous utility of the next-generation sequencing in identifying virus genetic diversity presents in ticks and other species of vectors and reservoirs.
Topics: Animals; Humans; Horses; Rhipicephalus; Amblyomma; Colombia; Virome; RNA Viruses
PubMed: 38402921
DOI: 10.1016/j.actatropica.2024.107158 -
Pathogens (Basel, Switzerland) Feb 2024Rift Valley fever phlebovirus (RVFV) is a highly pathogenic mosquito-borne virus with bioweapon potential due to its ability to be spread by aerosol transmission....
Rift Valley fever phlebovirus (RVFV) is a highly pathogenic mosquito-borne virus with bioweapon potential due to its ability to be spread by aerosol transmission. Neurological symptoms are among the worst outcomes of infection, and understanding of pathogenesis mechanisms within the brain is limited. RVFV is classified as an overlap select agent by the CDC and USDA; therefore, experiments involving fully virulent strains of virus are tightly regulated. Here, we present two methods for inactivation of live virus within samples derived from mouse microglia cells using commercially available kits for the preparation of cells for flow cytometry and RNA extraction. Using the flow cytometry protocol, we demonstrate key differences in the response of primary murine microglia to infection with fully virulent versus attenuated RVFV.
PubMed: 38392897
DOI: 10.3390/pathogens13020159 -
BMC Infectious Diseases Feb 2024This study aimed to investigate the clinical characteristics of severe fever with thrombocytopenia syndrome complicated by viral myocarditis (SFTS-VM) and analyze...
OBJECTIVE
This study aimed to investigate the clinical characteristics of severe fever with thrombocytopenia syndrome complicated by viral myocarditis (SFTS-VM) and analyze relevant influencing factors.
METHODS
Retrospective analysis was conducted on clinical data from 79 SFTS-VM patients, categorized into common (SFTS-CVM, n = 40) and severe groups (SFTS-SVM, n = 39). Clinical manifestations, laboratory results, cardiac ultrasonography, and electrocardiogram features were analyzed. Univariate and multivariate analyses identified significant indicators, which were further assessed using ROC curves to predict SFTS-SVM.
RESULTS
SFTS-SVM group exhibited higher rates of hypotension, shock, abdominal pain, cough with sputum, and consciousness disorders compared to SFTS-CVM group. Laboratory findings showed elevated platelet count, ALT, AST, amylase, lipase, LDH, D-dimer, procalcitonin, TNI, and NT-proBNP in SFTS-SVM. Abnormal electrocardiograms, especially atrial fibrillation, were more prevalent in SFTS-SVM (P < 0.05). Multivariate analysis identified elevated LDH upon admission (OR = 1.004, 95% CI: 1-1.008, P = 0.050), elevated NT-proBNP (OR = 1.005, 95% CI: 1.001-1.008, P = 0.007), and consciousness disorders (OR = 112.852, 95% CI: 3.676 ~ 3464.292, P = 0.007) as independent risk factors for SFTS-SVM. LDH and NT-proBNP had AUCs of 0.728 and 0.744, respectively, in predicting SFTS-SVM. Critical values of LDH (> 978.5U/L) and NT-proBNP (> 857.5pg/ml)) indicated increased likelihood of SFTS progression into SVM.
CONCLUSION
Elevated LDH, NT-proBNP, and consciousness disorders independently correlate with SFTS-SVM. LDH and NT-proBNP can aid in early identification of SFTS-SVM development when above specified thresholds.
Topics: Humans; Severe Fever with Thrombocytopenia Syndrome; Retrospective Studies; Thrombocytopenia; Myocarditis; Consciousness Disorders; Fever; Virus Diseases; Phlebovirus
PubMed: 38389047
DOI: 10.1186/s12879-024-09096-4 -
Microbiome Feb 2024Haemaphysalis longicornis is drawing attentions for its geographic invasion, extending population, and emerging disease threat. However, there are still substantial gaps...
BACKGROUND
Haemaphysalis longicornis is drawing attentions for its geographic invasion, extending population, and emerging disease threat. However, there are still substantial gaps in our knowledge of viral composition in relation to genetic diversity of H. longicornis and ecological factors, which are important for us to understand interactions between virus and vector, as well as between vector and ecological elements.
RESULTS
We conducted the meta-transcriptomic sequencing of 136 pools of H. longicornis and identified 508 RNA viruses of 48 viral species, 22 of which have never been reported. Phylogenetic analysis of mitochondrion sequences divided the ticks into two genetic clades, each of which was geographically clustered and significantly associated with ecological factors, including altitude, precipitation, and normalized difference vegetation index. The two clades showed significant difference in virome diversity and shared about one fifth number of viral species that might have evolved to "generalists." Notably, Bandavirus dabieense, the pathogen of severe fever with thrombocytopenia syndrome was only detected in ticks of clade 1, and half number of clade 2-specific viruses were aquatic-animal-associated.
CONCLUSIONS
These findings highlight that the virome diversity is shaped by internal genetic evolution and external ecological landscape of H. longicornis and provide the new foundation for promoting the studies on virus-vector-ecology interaction and eventually for evaluating the risk of H. longicornis for transmitting the viruses to humans and animals. Video Abstract.
Topics: Animals; Humans; Ixodidae; Haemaphysalis longicornis; Virome; Phylogeny; Phlebovirus; Ticks
PubMed: 38378577
DOI: 10.1186/s40168-024-01753-9 -
Veterinaria Italiana Jul 2023Phleboviruses are common human pathogens diffused on the Mediterranean area whose infection can cause the typical prodromal symptom of a mild three‑days fever. In...
Phleboviruses are common human pathogens diffused on the Mediterranean area whose infection can cause the typical prodromal symptom of a mild three‑days fever. In particular, Toscana Virus (TOSV) has a great concern since its capacity to provoke central nervous system disorders like meningoencephalitis. Furthermore, as the phlebotomine arthropod vectors represent the main carrier for pathogens of the genus Leishmania as well, the purpose of the study was to investigate the presence of TOSV in Lampedusa, Italy previously reported for leishmaniosis infection cases. The survey was carried out through an initial sampling phase of sand flies, by means of CDC light traps, and a second step of molecular analyses. The genomic S‑segment of TOSV was targeted. The positive samples were sequenced and compared with those available in GenBank™ using Basic Local Alignments Tool (BLAST) analyses. The study revealed for the first time the presence of TOSV in Lampedusa, Italy. The entomological studies directed on vectors are currently widely used in sand fly surveillance, and new data on TOSV are of public health concern.
Topics: Animals; Humans; Phlebovirus; Psychodidae; Phlebotomus; Italy; Meningoencephalitis
PubMed: 38376831
DOI: 10.12834/VetIt.2711.17825.2 -
EMBO Molecular Medicine Mar 2024Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening disease caused by a novel bunyavirus (SFTSV), mainly transmitted by ticks. With no effective...
Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening disease caused by a novel bunyavirus (SFTSV), mainly transmitted by ticks. With no effective therapies or vaccines available, understanding the disease's mechanisms is crucial. Recent studies found increased expression of programmed cell death-1 (PD-1) on dysfunctional T cells in SFTS patients. However, the role of the PD-1/programmed cell death-ligand 1 (PD-L1) pathway in SFTS progression remains unclear. We investigated PD-1 blockade as a potential therapeutic strategy against SFTSV replication. Our study analyzed clinical samples and performed in vitro experiments, revealing elevated PD-1/PD-L1 expression in various immune cells following SFTSV infection. An anti-PD-1 nanobody, NbP45, effectively inhibited SFTSV infection in peripheral blood mononuclear cells (PBMCs), potentially achieved through the mitigation of apoptosis and the augmentation of T lymphocyte proliferation. Intriguingly, subcutaneous administration of NbP45 showed superior efficacy compared to a licensed anti-PD-1 antibody in an SFTSV-infected humanized mouse model. These findings highlight the involvement of the PD-1/PD-L1 pathway during acute SFTSV infection and suggest its potential as a host target for immunotherapy interventions against SFTSV infection.
Topics: Animals; Humans; Mice; Bunyaviridae Infections; Phlebovirus; B7-H1 Antigen; Severe Fever with Thrombocytopenia Syndrome; Leukocytes, Mononuclear; Programmed Cell Death 1 Receptor
PubMed: 38366162
DOI: 10.1038/s44321-024-00026-0