Sindbis and Middelburg Old World Alphaviruses Associated with Neurologic Disease in Horses, South Africa.
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ABSTRACT:
SUBMITTER: van Niekerk S
PROVIDER: S-EPMC4672445 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The Orthobunyavirus genus, family Peribunyaviridae, contains several important emerging and re-emerging arboviruses of veterinary and medical importance. These viruses may cause mild febrile illness, to severe encephalitis, fetal deformity, abortion, hemorrhagic fever and death in humans and/or animals. Shuni virus (SHUV) is a zoonotic arbovirus thought to be transmitted by hematophagous arthropods. It was previously reported in a child in Nigeria in 1966 and horses in Southern Africa in the 1970s and again in 2009, and in humans with neurological signs in 2017. Here we investigated the epidemiology and phylogenetic relationship of SHUV strains detected in horses presenting with febrile and neurological signs in South Africa. In total, 24/1820 (1.3%) horses submitted to the zoonotic arbovirus surveillance program tested positive by real-time reverse transcription (RTPCR) between 2009 and 2019. Cases were detected in all provinces with most occurring in Gauteng (9/24, 37.5%). Neurological signs occurred in 21/24 (87.5%) with a fatality rate of 45.8%. Partial sequencing of the nucleocapsid gene clustered the identified strains with SHUV strains previously identified in South Africa (SA). Full genome sequencing of a neurological case detected in 2016 showed 97.8% similarity to the SHUV SA strain (SAE18/09) and 97.5% with the Nigerian strain and 97.1% to the 2014 Israeli strain. Our findings suggest that SHUV is circulating annually in SA and despite it being relatively rare, it causes severe neurological disease and death in horses.
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Project description:Background and aimsSalvia is the largest genus in Lamiaceae and it has recently been found to be non-monophyletic. Molecular data on Old World Salvia are largely lacking. In this study, we present data concerning Salvia in Africa. The focus is on the colonization of the continent, character evolution and the switch of pollination systems in the genus.MethodsMaximum likelihood and Bayesian inference were used for phylogenetic reconstruction. Analyses were based on two nuclear markers [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and one plastid marker (rpl32-trnL). Sequence data were generated for 41 of the 62 African taxa (66 %). Mesquite was used to reconstruct ancestral character states for distribution, life form, calyx shape, stamen type and pollination syndrome.Key resultsSalvia in Africa is non-monophyletic. Each of the five major regions in Africa, except Madagascar, was colonized at least twice, and floristic links between North African, south-west Asian and European species are strongly supported. The large radiation in Sub-Saharan Africa (23 species) can be traced back to dispersal from North Africa via East Africa to the Cape Region. Adaptation to bird pollination in southern Africa and Madagascar reflects parallel evolution.ConclusionsThe phenotypic diversity in African Salvia is associated with repeated introductions to the continent. Many important evolutionary processes, such as colonization, adaptation, parallelism and character transformation, are reflected in this comparatively small group. The data presented in this study can help to understand the evolution of Salvia sensu lato and other large genera.
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