27 research outputs found
Lagos bat virus, an under-reported rabies-related lyssavirus
Lagos bat virus (LBV), one of the 17 accepted viral species of the Lyssavirus genus, was
the first rabies-related virus described in 1956. This virus is endemic to the African continent and
is rarely encountered. There are currently four lineages, although the observed genetic diversity
exceeds existing lyssavirus species demarcation criteria. Several exposures to rabid bats infected
with LBV have been reported; however, no known human cases have been reported to date. This
review provides the history of LBV and summarizes previous knowledge as well as new detections.
Genetic diversity, pathogenesis and prevention are re-evaluated and discussed.This research is supported in part by the South African Research Chair Initiative (held by
Wanda Markotter) of the Department of Science and Innovation and administered by the National
Research Foundation of South Africa (UID: 98339). The National Research Foundation funded the
equipment based at the DNA Sanger sequencing facility in the Faculty of Natural and Agricultural
Sciences, University of Pretoria (UID: 78566).https://www.mdpi.com/journal/virusesdm2022Medical Virolog
Overview of bat and wildlife coronavirus surveillance in Africa : a framework for global investigations
The ongoing coronavirus disease 2019 (COVID-19) pandemic has had devastating health
and socio-economic impacts. Human activities, especially at the wildlife interphase, are at the core
of forces driving the emergence of new viral agents. Global surveillance activities have identified
bats as the natural hosts of diverse coronaviruses, with other domestic and wildlife animal species
possibly acting as intermediate or spillover hosts. The African continent is confronted by several
factors that challenge prevention and response to novel disease emergences, such as high species
diversity, inadequate health systems, and drastic social and ecosystem changes. We reviewed
published animal coronavirus surveillance studies conducted in Africa, specifically summarizing
surveillance approaches, species numbers tested, and findings. Far more surveillance has been
initiated among bat populations than other wildlife and domestic animals, with nearly 26,000 bat
individuals tested. Though coronaviruses have been identified from approximately 7% of the total
bats tested, surveillance among other animals identified coronaviruses in less than 1%. In addition to
a large undescribed diversity, sequences related to four of the seven human coronaviruses have been
reported from African bats. The review highlights research gaps and the disparity in surveillance
efforts between different animal groups (particularly potential spillover hosts) and concludes with
proposed strategies for improved future biosurveillance.The National Research Foundation (NRF) of South Africa: the DSI-NRF South African Research Chair fellowship funding; the Department of the Defense, Defense Threat Reduction Agency and the University of Pretoria’s postdoctoral funding program.http://www.mdpi.com/journal/virusespm2021Medical Virolog
Seasonal shedding patterns of diverse henipavirus-related paramyxoviruses in Egyptian rousette bats
Bat-borne viruses in the Henipavirus genus have been associated with zoonotic diseases of high morbidity and mortality in Asia and Australia. In Africa, the Egyptian rousette bat species (Rousettus aegyptiacus) is an important viral host in which Henipavirus-related viral sequences have previously been identified. We expanded these fndings by assessing the viral dynamics in a southern African bat population. A longitudinal study of henipavirus diversity and excretion dynamics identified 18 putative viral species circulating in a local population, three with difering seasonal dynamics, and the winter and spring periods posing a higher risk of virus spill over and transmission. The annual peaks in virus excretion are most likely driven by subadults and may be linked to the waning of maternal immunity and recolonization of the roost in early spring. These results provide insightful information into the bat-host relationship that can be extrapolated to other populations across Africa and be communicated to at-risk communities as a part of evidence-based public health education and prevention measures against pathogen spill over threats.The National Research Foundation (NRF) of South Africa; the Poliomyelitis Research Foundation; the Department of the Defense, Defense Treat Reduction Agency, the South African Medical Research Council and the University of Pretoria’s postdoctoral funding program.http://www.nature.com/srep/index.htmlMedical Virolog
Viral maintenance and excretion dynamics of coronaviruses within an Egyptian rousette fruit bat maternal colony : considerations for spillover
DATA AVAILABILITY : All data generated during this study are included in this published article (and its Supplementary Information
files). All model code as well as diagnostic reports are available in the GitHub project code repository (https://github.com/ecohealthalliance/sabrenet-rousettus-dynamics/, with a version on Zenodo https://zenodo. org/record/7709716).Novel coronavirus species of public health and veterinary importance have emerged in the first
two decades of the twenty-first century, with bats identified as natural hosts for progenitors of
many coronaviruses. Targeted wildlife surveillance is needed to identify the factors involved in viral
perpetuation within natural host populations, and drivers of interspecies transmission. We monitored
a natural colony of Egyptian rousette bats at monthly intervals across two years to identify circulating
coronaviruses, and to investigate shedding dynamics and viral maintenance within the colony.
Three distinct lineages were detected, with different seasonal temporal excretion dynamics. For
two lineages, the highest periods of coronavirus shedding were at the start of the year, when large
numbers of bats were found in the colony. Highest peaks for a third lineage were observed towards
the middle of the year. Among individual bat-level factors (age, sex, reproductive status, and forearm
mass index), only reproductive status showed significant effects on excretion probability, with
reproductive adults having lower rates of detection, though factors were highly interdependent.
Analysis of recaptured bats suggests that viral clearance may occur within one month. These
findings may be implemented in the development of risk reduction strategies for potential zoonotic
coronavirus transmission.The National Research Foundation (NRF) of South Africa, the Poliomyelitis Research Foundation, the Department of the Defense, Defense Threat Reduction Agency and the University of Pretoria’s postdoctoral funding program.https://www.nature.com/srepam2024Medical VirologyNon
Southern Africa's great escarpment as an amphitheater of climate-driven diversification and a buffer against future climate change in bats
DATA AVAILABILITY STATEMENT :
Raw cyt-b sequence data (FASTA files; Datasets S1–S3) and craniometric and specimen data (Excel files; Datasets S4–S7) are openly available on Dryad at https://doi.org/10.5061/dryad.3bk3j9ksc.Hosting 1460 plant and 126 vertebrate endemic species, the Great Escarpment (hereafter, Escarpment) forms a semi-circular “amphitheater” of mountains girdling southern Africa from arid west to temperate east. Since arid and temperate biota are usually studied separately, earlier studies overlooked the biogeographical importance of the Escarpment as a whole. Bats disperse more widely than other mammalian taxa, with related species and intraspecific lineages occupying both arid and temperate highlands of the Escarpment, providing an excellent model to address this knowledge gap. We investigated patterns of speciation and micro-endemism from modeled past, present, and future distributions in six clades of southern African bats from three families (Rhinolophidae, Cistugidae, and Vespertilionidae) having different crown ages (Pleistocene to Miocene) and biome affiliations (temperate to arid). We estimated mtDNA relaxed clock dates of key divergence events across the six clades in relation both to biogeographical features and patterns of phenotypic variation in crania, bacula and echolocation calls. In horseshoe bats (Rhinolophidae), both the western and eastern “arms” of the Escarpment have facilitated dispersals from the Afrotropics into southern Africa. Pleistocene and pre-Pleistocene “species pumps” and temperate refugia explained observed patterns of speciation, intraspecific divergence and, in two cases, mtDNA introgression. The Maloti-Drakensberg is a center of micro-endemism for bats, housing three newly described or undescribed species. Vicariance across biogeographic barriers gave rise to 29 micro-endemic species and intraspecific lineages whose distributions were congruent with those identified in other phytogeographic and zoogeographic studies. Although Köppen–Geiger climate models predict a widespread replacement of current temperate ecosystems in southern Africa by tropical or arid ecosystems by 2070–2100, future climate Maxent models for 13 bat species (all but one of those analyzed above) showed minimal range changes in temperate species from the eastern Escarpment by 2070, possibly due to the buffering effect of mountains to climate change.National Research Foundation and
Department of Science and Innovation
of South Africa; Afromontane Research Unit,
University of the Free State; National
Research Foundation.http://www.wileyonlinelibrary.com/journal/gcbhj2024Medical VirologySDG-15:Life on lan
Advances in understanding bat infection dynamics across biological scales
Over the past two decades, research on bat-associated microbes such as viruses, bacteria and fungi has dramatically increased. Here, we synthesize themes from a conference symposium focused on advances in the research of bats and their microbes, including physiological, immunological, ecological and epidemiological research that has improved our understanding of bat infection dynamics at multiple biological scales. We first present metrics for measuring individual bat responses to infection and challenges associated with using these metrics. We next discuss infection dynamics within bat populations of the same species, before introducing complexities that arise in multi-species communities of bats, humans and/or livestock. Finally, we outline critical gaps and opportunities for future interdisciplinary work on topics involving bats and their microbes
Detection and characterization of coronaviruses from African bat species
The severe acute respiratory disease syndrome or SARS epidemic emerged in Hong
Kong, China, in 2002 with a mortality rate of 15%. The etiological agent for SARS was
identified to be a previously unrecognized coronavirus (SARS-CoV) which was found to be
zoonotic in origin. A possible reservoir for the SARS-CoV was proposed to be the Chinese
horseshoe bat species (Rhinolophus spp.) due to the detection of SARS-related bat
coronaviruses (BtCoV) within these bat species. Since the SARS-CoV epidemic, new
interest regarding the origin and pathogenicity of coronaviruses has been generated. As
such, surveillance studies of BtCoV in numerous bat species have been performed in Asia,
Europe, North and South America as well as 3 African countries. Recent BtCoV
investigations in Kenya, Ghana and Nigeria identified BtCoV from both the Alpha- and
Betacoronavirus genera and provided the first evidence for the presence of coronaviruses in
African bats. Previously, the presence of antibodies against SARS-related CoV has been
reported in two bat species native to South Africa. This study investigated the possible
presence of BtCoV in a panel of bat specimens collected from sites in South Africa and
Rwanda, and how they are related to previously detected BtCoVs from other parts of the
world.
Here we report the development of two PCR assays, the PanBtCoV/9 primer nested
RT-PCR and PanBat/AB/6 primer hemi-nested RT-PCR assay, which were used in
coronavirus detection from alimentary specimens collected from 15 bat genera. The
combined assays amplified coronavirus RNA from 5 samples of the 201 analysed samples
collected in South Africa (n=113) and Rwanda (n=88).
Three alphacoronaviruses were detected in 3 different South African bat species,
Miniopterus spp. (Miniopterus-Bat coronavirus/Irene/South Africa/2009), Neoromicia
capensis (Neoromicia-Bat coronavirus/167/South Africa/2007), and Mops midas (Mops-Bat
coronavirus/1364/South Africa/2011). From Rwanda, a single betacoronavirus, a SARSrCoV was detected within 2 Rhinolophus spp. individuals (Rh-BtCoV/441/Rwanda/08 and Rh-
BtCoV/445/Rwanda/08). Phylogenetic analysis of these sequences was performed and
showed that the South African Miniopterus alphacoronavirus and the Rwandan
betacoronavirus cluster together with previously detected African BtCoV from the same host
genera. The South African alphacoronavirus from Mops midas was closely related to an
alphacoronavirus identified within another member of the Molossidae family, Chaerephon
spp. from Kenya. Being the first BtCoV identified from the Neoromicia genus, no African
BtCoV sequences were available for comparison and as such the virus clustered together
with European BtCoV from the Nyctalus spp., another member of the Vespertilioninae
subfamily.
This study has detected the first BtCoV viral RNA from the native bat species of South
Africa and Rwanda, providing confirmation to the presence of bat coronaviruses circulating
in these countries. From these preliminary results further investigations into the prevalence
and infection cycles of bat coronaviruses in specific bat populations can be performed in the
future.
The possibility of either these alpha- or betacoronaviruses spilling over and eventually
adapting to and infecting other species, though unlikely, cannot be excluded since such rare
events are hypothetically responsible for the establishment coronaviruses in humans,
livestock, poultry and pets. Caution may still be merited when interacting with bats in roosts
and caves.Dissertation (MSc)--University of Pretoria, 2012.National Research foundation (NRF)Poliomyelitis Research Foundation (PRF)Microbiology and Plant PathologyMScUnrestricte
Detection and Characterization of an H9N2 Influenza A Virus in the Egyptian Rousette Bat in Limpopo, South Africa
In recent years, bats have been shown to host various novel bat-specific influenza viruses, including H17N10 and H18N11 in the Americas and the H9N2 subtype from Africa. Rousettus aegyptiacus (Egyptian Rousette bat) is recognized as a host species for diverse viral agents. This study focused on the molecular surveillance of a maternal colony in Limpopo, South Africa, between 2017–2018. A pan-influenza hemi-nested RT-PCR assay targeting the PB1 gene was established, and influenza A virus RNA was identified from one fecal sample out of 860 samples. Genome segments were recovered using segment-specific amplification combined with standard Sanger sequencing and Illumina unbiased sequencing. The identified influenza A virus was closely related to the H9N2 bat-influenza virus, confirming the circulation of this subtype among Egyptian fruit bat populations in Southern Africa. This bat H9N2 subtype contained amino acid residues associated with transmission and virulence in either mammalian or avian hosts, though it will likely require additional adaptations before spillover
Host-Associated Distribution of Two Novel Mammarenaviruses in Rodents from Southern Africa
Mammarenaviruses are hosted by several rodent species, a small number of which have been known to be zoonotic. Host surveillance among small mammals has identified a large diversity of previously undescribed mammarenaviruses. Intensified biosurveillance is warranted to better understand the diversity of these agents. Longitudinal host surveillance involving non-volant small mammals at a site in the Limpopo province, South Africa, was conducted. The study reports on the screening results of 563 samples for the presence of mammarenavirus RNA. PCR-positive samples were subjected to sequencing using Miseq amplicon sequencing. Sequences with close similarity to Mariental and Lunk viruses were identified from two rodent species, Micaelamys namaquensis and Mus minutoides. This represents the first description of these viruses from South Africa. The genomic sequences reported here partially satisfied the requirements put forward by the International Committee on the Taxonomy of Viruses’ criteria for species delineation, suggesting that these may be new strains of existing species. The known distribution of these mammarenaviruses is thus expanded further south in Africa
Coronaviruses in south africanbats
Recent studies in several African countries have provided the first evidence for the presence of coronaviruses in African bats. Here we describe, for the first time, the detection of RNA of 3 unique coronavirus species in the tissues of South African bats