Year: 2012
Type: dissertation
Abstract: The severe acute respiratory disease syndrome or SARS epidemic emerged in Hong \nKong, China, in 2002 with a mortality rate of 15%. The etiological agent for SARS was \nidentified to be a previously unrecognized coronavirus (SARS-CoV) which was found to be \nzoonotic in origin. A possible reservoir for the SARS-CoV was proposed to be the Chinese \nhorseshoe bat species (Rhinolophus spp.) due to the detection of SARS-related bat \ncoronaviruses (BtCoV) within these bat species. Since the SARS-CoV epidemic, new \ninterest regarding the origin and pathogenicity of coronaviruses has been generated. As \nsuch, surveillance studies of BtCoV in numerous bat species have been performed in Asia, \nEurope, North and South America as well as 3 African countries. Recent BtCoV \ninvestigations in Kenya, Ghana and Nigeria identified BtCoV from both the Alpha- and \nBetacoronavirus genera and provided the first evidence for the presence of coronaviruses in \nAfrican bats. Previously, the presence of antibodies against SARS-related CoV has been \nreported in two bat species native to South Africa. This study investigated the possible \npresence of BtCoV in a panel of bat specimens collected from sites in South Africa and \nRwanda, and how they are related to previously detected BtCoVs from other parts of the \nworld. \nHere we report the development of two PCR assays, the PanBtCoV/9 primer nested \nRT-PCR and PanBat/AB/6 primer hemi-nested RT-PCR assay, which were used in \ncoronavirus detection from alimentary specimens collected from 15 bat genera. The \ncombined assays amplified coronavirus RNA from 5 samples of the 201 analysed samples \ncollected in South Africa (n=113) and Rwanda (n=88). \nThree alphacoronaviruses were detected in 3 different South African bat species, \nMiniopterus spp. (Miniopterus-Bat coronavirus/Irene/South Africa/2009), Neoromicia \ncapensis (Neoromicia-Bat coronavirus/167/South Africa/2007), and Mops midas (Mops-Bat \ncoronavirus/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- \nBtCoV/445/Rwanda/08). Phylogenetic analysis of these sequences was performed and \nshowed that the South African Miniopterus alphacoronavirus and the Rwandan \nbetacoronavirus cluster together with previously detected African BtCoV from the same host \ngenera. The South African alphacoronavirus from Mops midas was closely related to an \nalphacoronavirus identified within another member of the Molossidae family, Chaerephon \nspp. from Kenya. Being the first BtCoV identified from the Neoromicia genus, no African \nBtCoV sequences were available for comparison and as such the virus clustered together \nwith European BtCoV from the Nyctalus spp., another member of the Vespertilioninae \nsubfamily. \nThis study has detected the first BtCoV viral RNA from the native bat species of South \nAfrica and Rwanda, providing confirmation to the presence of bat coronaviruses circulating \nin these countries. From these preliminary results further investigations into the prevalence \nand infection cycles of bat coronaviruses in specific bat populations can be performed in the \nfuture. \nThe possibility of either these alpha- or betacoronaviruses spilling over and eventually \nadapting to and infecting other species, though unlikely, cannot be excluded since such rare \nevents are hypothetically responsible for the establishment coronaviruses in humans, \nlivestock, poultry and pets. Caution may still be merited when interacting with bats in roosts \nand caves.
Author: Marike Geldenhuys
Language: English
Subfield: Animal Science and Zoology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2792734399