Skip to main content

Broad geographical #circulation of a novel #vesiculovirus in #bats in the #Mediterranean region

Abstract

Bats are the natural reservoirs for a variety of emerging and re-emerging viruses. Among them, rabies virus (genus Lyssavirus, family Rhabdoviridae) is one of the first and most emblematic described in these animals. Since its first description, several new bat lyssaviruses have been regularly identified. In addition to lyssaviruses, other bat rhabdoviruses have also been discovered, including members of the genera Vesiculovirus, Ledantevirus and, more recently, Alphanemrhavirus and Tupavirus. However, the family Rhabdoviridae is one of the most abundant and diverse viral families, with 434 officially recognized species, divided into 5 subfamilies and 56 different genera. The number of rhabdoviruses associated with bats is therefore probably higher than that currently available. In this study, we first developed and validated a combined nested RT-qPCR technique (pan-rhabdo RT-nqPCR) dedicated to the broad detection of animal rhabdoviruses. After validation, this technique was used for a large retrospective screening of archival bat samples (n = 1962), including blood (n = 816), brain (n = 723) and oral swab (n = 423). These samples were collected from various bat species over a 12-year period (2007–2019) in 9 different countries in Europe and Africa. A total of 23 samples (1.2%) from bat species Miniopterus schreibersii, Rhinolophus euryale and Rhinolophus ferrumequinum tested positive for rhabdovirus infection, including 17 (2.1%) blood and 6 (1.4%) oral swab samples, all collected from bats originating from the Mediterranean region. Complete virus genome sequences were obtained by next-generation sequencing for most of the positive samples. Molecular and phylogenetic analysis of these sequences demonstrated that these virus isolates, named Mediterranean bat virus (MBV), were closely related and represented a new species, Mediterranean vesiculovirus, within the Vesiculovirus genus. MBV was more specifically related to other bat vesiculoviruses previously described from China and North America, together clustering into a distinct group of bat viruses within this genus. Interestingly, our results suggest that MBV is widespread, at least in the western part of the Mediterranean region, where it circulates in the blood of several bat species. These results expand the host range and viral diversity of bat vesiculoviruses, and pave the way for further studies to determine the transmission route and dissemination dynamics of these viruses in bat colonies, as well as to assess their potential threat to public health.


Author summary

Bats are the natural hosts for a wide variety of viruses, particularly those belonging to the family Rhabdoviridae, which include the lyssaviruses, the etiological agents of rabies. This viral family is one of the most abundant and diverse, with 434 officially recognized species. However, the current diversity of these viruses in bats remains poorly understood. To address this, we developed a new method for detecting rhabdoviruses in bat samples collected over a period of 12 years in several European and African countries. From nearly 2,000 samples, we discovered a new rhabdovirus, which was named Mediterranean bat virus (MBV). MBV has been detected in the blood and oral swabs of specific bat species (Rhinolophus sp. and Miniopterus schreibersii) living on both sides of the Mediterranean region. Based on phylogenetic analysis, we determined that MBV represented a unique group within the genus Vesiculovirus, but still related to other bat vesiculoviruses discovered in China and North America. These results expand the host range and viral diversity of bat rhabdoviruses, and pave the way for further studies to determine the transmission route and dissemination dynamics of these viruses in bat colonies, as well as to assess their potential threat to public health.

Source: PLoS Neglected Tropical Diseases, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0013172

____

Comments

Popular posts from this blog

#Neuroinvasive #Oropouche virus in a patient with #HIV from extra-Amazonian #Brazil

{Excerpt} A novel reassortant Oropouche virus (OROV) lineage (with medium [M], large [L], and small [S] RNA segments : M1L2S2) has driven Brazil's largest and most geographically widespread OROV epidemic , expanding beyond the endemic Amazon basin to establish local transmission across multiple Brazilian states and other previously unaffected Latin American countries . The rapid spread of this lineage underscores its evolutionary potential and reinforces its significance as a public health threat .1 Similar to chikungunya and Zika viruses, expanding arboviruses can exhibit unexpected clinical and epidemiological shifts , including vertical transmissions , neuroinvasive effects, and potentially fatal outcomes.2–4 Although OROV typically causes self-limited febrile illness, accumulating clinical and experimental evidence suggests neurotropic potential .5 This Correspondence describes the first confirmed case of neuroinvasive OROV infection caused by the emergent M1L2S2 lineage in ext...

No evidence of immune #exhaustion after repeated #SARS-CoV-2 #vaccination in vulnerable and healthy populations

Abstract Frequent SARS-CoV-2 vaccination in vulnerable populations has raised concerns that this may contribute to T cell exhaustion , which could negatively affect the quality of immune protection. Herein, we examined the impact of repeated SARS-CoV-2 vaccination on T cell phenotypic and functional exhaustion in frail older adults in long-term care (n = 23), individuals on immunosuppressive drugs (n = 10), and healthy adults (n = 43), in Canada . Spike-specific CD4+ and CD8+ T cell levels did not decline in any cohort following repeated SARS-CoV-2 vaccination, nor did the expression of exhaustion markers on spike-specific or total T cells increase. T cell production of multiple cytokines (i.e. polyfunctionality) in response to the spike protein of SARS-CoV-2 did not decline in any cohort following repeated vaccination. None of the cohorts displayed elevated levels of terminally differentiated T cells following multiple SARS-CoV-2 vaccinations. Thus, repeated SARS-CoV-2 vaccination was...

Chimeric #hemagglutinin and #M2 #mRNA #vaccine for broad #influenza subtype protection

Abstract Since multiple and unpredicted influenza viruses cause seasonal epidemics and even high-risk pandemics , developing a universal influenza vaccine is essential to provide broad protection against various influenza subtypes. Combined with the mRNA lipid nanoparticle-encapsulated (mRNA-LNP) vaccine platform and chimeric immunogen strategy , we developed a novel cocktail mRNA vaccine encoding chimeric HAs (cH5/1-BV, cH7/3) and intact M2 (termed Fluaxe), which confers broad protection against major circulating IAVs and IBVs , as well as highly pathogenic avian influenza . Two-dose intramuscular immunization of Fluaxe in mice elicited cross-reactive neutralizing antibodies , T cell responses, and long-lived immunity, resulting in robust protection against multiple lethal influenza virus infections and severe acute lung injuries . In particular, intramuscular administration stimulated systemic immunity together with a prominent lung tropism of memory cells . Moreover, Fluaxe immuniza...