RESUMO
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.
Assuntos
Quirópteros , Mudança Climática , DNA Mitocondrial , Animais , Quirópteros/fisiologia , Quirópteros/genética , África Austral , DNA Mitocondrial/genética , DNA Mitocondrial/análise , Filogenia , Especiação Genética , Filogeografia , Distribuição AnimalRESUMO
We detected 3 lyssaviruses in insectivorous bats sampled in South Africa during 2003-2018. We used phylogenetic analysis to identify Duvenhage lyssavirus and a potentially new lyssavirus, provisionally named Matlo bat lyssavirus, that is related to West Caucasian bat virus. These new detections highlight that much about lyssaviruses remains unknown.
Assuntos
Quirópteros , Lyssavirus , Raiva , Infecções por Rhabdoviridae , Animais , Lyssavirus/genética , Filogenia , Infecções por Rhabdoviridae/epidemiologia , Infecções por Rhabdoviridae/veterinária , África do Sul/epidemiologiaRESUMO
As part of a larger survey for detection of pathogens among wildlife in sub-Saharan Africa conducted during 2007-2012, multiple diverse paramyxovirus sequences were detected in renal tissues of bats. Phylogenetic analysis supports the presence of at least 2 major viral lineages and suggests that paramyxoviruses are strongly associated with several bat genera.
Assuntos
Quirópteros/virologia , Henipavirus/patogenicidade , Infecções por Paramyxoviridae/epidemiologia , Paramyxovirinae/classificação , Prevalência , África Subsaariana/epidemiologia , Animais , Infecções por Paramyxoviridae/virologia , Filogenia , Vigilância da População/métodos , RNA Viral/classificação , RNA Viral/genéticaRESUMO
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.
Assuntos
Arenaviridae , Animais , Arenaviridae/genética , Filogenia , África Austral , Mamíferos , MurinaeRESUMO
The reservoir host of Mokola virus (MOKV), a rabies-related lyssavirus species endemic to Africa, remains unknown. Only sporadic cases of MOKV have been reported since its first discovery in the late 1960s, which subsequently gave rise to various reservoir host hypotheses. One particular hypothesis focusing on non-volant small mammals (e.g. shrews, sengis and rodents) is buttressed by previous MOKV isolations from shrews (Crocidura sp.) and a single rodent (Lophuromys sikapusi). Although these cases were only once-off detections, it provided evidence of the first known lyssavirus species has an association with non-volant small mammals. To investigate further, retrospective surveillance was conducted in 575 small mammals collected from South Africa. Nucleic acid surveillance using a pan-lyssavirus quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay of 329 brain samples did not detect any lyssavirus ribonucleic acid (RNA). Serological surveillance using a micro-neutralisation test of 246 serum samples identified 36 serum samples that were positive for the presence of MOKV neutralising antibodies (VNAs). These serum samples were all collected from Gerbilliscus leucogaster (Bushveld gerbils) rodents from Meletse in Limpopo province (South Africa). Mokola virus infections in Limpopo province have never been reported before, and the high MOKV seropositivity of 87.80% in these gerbils may indicate a potential rodent reservoir.
Assuntos
Lyssavirus , Raiva , Animais , Mamíferos , Raiva/epidemiologia , Raiva/veterinária , Estudos Retrospectivos , África do Sul/epidemiologiaRESUMO
Most vertebrates host a wide variety of haematophagous parasites, which may play an important role in the transmission of vector-borne microorganisms to hosts. Surveillance is usually performed by collecting blood and/or tissue samples from vertebrate hosts. There are multiple methods to obtain samples, which can be stored for decades if properly kept. However, blood sampling is considered an invasive method and may possibly be harmful to the sampled individual. In this study, we investigated the use of ectoparasites as a tool to acquire molecular information about the presence and diversity of infectious microorganism in host populations. We tested the presence of three distinct vector-borne microorganisms in both bat blood and bat flies: Bartonella bacteria, malaria-like Polychromophilus sp. (Apicomplexa), and Trypanosoma sp. (Kinetoplastea). We detected the presence of these microorganisms both in bats and in their bat flies, with the exception of Trypanosoma sp. in South African bat flies. Additionally, we found Bartonella sp. in bat flies from one population in Spain, suggesting its presence in the host population even if not detected in bats. Bartonella and Polychromophilus infection showed the highest prevalence in both bat and bat fly populations. Single, co- and triple infections were also frequently present in both. We highlight the use of haematophagous ectoparasites to study the presence of infectious microorganism in host blood and its use as an alternative, less invasive sampling method.
TITLE: Conservation des hôtes grâce à leurs parasites : surveillance moléculaire des microorganismes à transmission vectorielle chez les chauves-souris à l'aide de mouches ectoparasites. ABSTRACT: La plupart des vertébrés hébergent une grande variété de parasites hématophages, qui peuvent jouer un rôle important dans la transmission de microorganismes à transmission vectorielle à leurs hôtes. La surveillance est généralement effectuée en prélevant des échantillons de sang et/ou de tissus sur des hôtes vertébrés. Il existe plusieurs méthodes pour obtenir des échantillons, qui peuvent être conservés pendant des décennies dans des bonnes conditions. Cependant, le prélèvement sanguin est considéré comme une méthode invasive et peut éventuellement être nocif pour l'individu prélevé. Dans cette étude, nous avons étudié l'utilisation d'ectoparasites comme outil pour acquérir des informations moléculaires sur la présence et la diversité des microorganismes infectieux dans les populations hôtes. Nous avons testé la présence de trois microorganismes distincts, transmis par des vecteurs, dans le sang et les mouches des chauves-souris : les bactéries Bartonella, Polychromophilus sp. (Apicomplexa) et Trypanosoma sp. (Kinetoplastea). Nous avons détecté la présence de ces microorganismes à la fois chez les chauves-souris et chez leurs mouches des chauves-souris, à l'exception de Trypanosoma sp. chez les chauves-souris sud-africaines. De plus, nous avons trouvé Bartonella sp. chez les mouches des chauves-souris d'une population en Espagne, ce qui suggère sa présence dans la population hôte même si elle n'est pas détectée chez les chauves-souris elles-mêmes. Les infections à Bartonella et Polychromophilus ont montré la prévalence la plus élevée dans les populations de chauves-souris et de mouches des chauves-souris. Des infections simples, doubles et triples étaient également fréquemment présentes dans les deux cas. Nous mettons en évidence l'utilisation d'ectoparasites hématophages pour étudier la présence de microorganismes infectieux dans le sang de l'hôte et son utilisation comme méthode alternative et moins invasive d'échantillonnage.
Assuntos
Bartonella , Quirópteros , Conservação dos Recursos Naturais , Dípteros , Parasitos , Vigilância da População , Animais , Apicomplexa/isolamento & purificação , Bartonella/genética , Bartonella/isolamento & purificação , Infecções por Bartonella/epidemiologia , Infecções por Bartonella/microbiologia , Quirópteros/microbiologia , Quirópteros/parasitologia , Conservação dos Recursos Naturais/métodos , Dípteros/microbiologia , Dípteros/parasitologia , Parasitos/isolamento & purificação , Filogenia , Vigilância da População/métodos , Prevalência , Infecções Protozoárias em Animais/epidemiologia , Infecções Protozoárias em Animais/parasitologia , Espanha/epidemiologia , Trypanosoma/isolamento & purificaçãoRESUMO
Seasonal reproduction is a period of extreme physiological and behavioural changes, yet we know little about how it may affect host microbial communities (i.e. microbiota) and pathogen transmission. Here, we investigated shifts of the bacterial microbiota in saliva, urine and faeces during the seasonal reproduction of bats in South Africa, and test for an interaction in shedding patterns of both bacterial (Leptospira) and viral (adeno- and herpesviruses) agents. Based on a comparative approach in two cave-dwelling bat species and high-throughput sequencing of the 16S rRNA gene, we demonstrated a clear signature in microbiota changes over the reproduction season, consistent across the multiple body habitats investigated, and associated with the sex, age and reproductive condition of bats. We observed in parallel highly dynamic shedding patterns for both bacteria and viruses, but did not find a significant association between viral shedding and bacterial microbiota composition. Indeed, only Leptospira shedding was associated with alterations in both the diversity and composition of the urinary microbiota. These results illustrate how seasonal reproduction in bats substantially affects microbiota composition and infection dynamics, and have broad implications for the understanding of disease ecology in important reservoir hosts, such as bats.
RESUMO
Species within the Neoromicia bat genus are abundant and widely distributed in Africa. It is common for these insectivorous bats to roost in anthropogenic structures in urban regions. Additionally, Neoromicia capensis have previously been identified as potential hosts for Middle East respiratory syndrome (MERS)-related coronaviruses. This study aimed to ascertain the gastrointestinal virome of these bats, as viruses excreted in fecal material or which may be replicating in rectal or intestinal tissues have the greatest opportunities of coming into contact with other hosts. Samples were collected in five regions of South Africa over eight years. Initial virome composition was determined by viral metagenomic sequencing by pooling samples and enriching for viral particles. Libraries were sequenced on the Illumina MiSeq and NextSeq500 platforms, producing a combined 37 million reads. Bioinformatics analysis of the high throughput sequencing data detected the full genome of a novel species of the Circoviridae family, and also identified sequence data from the Adenoviridae, Coronaviridae, Herpesviridae, Parvoviridae, Papillomaviridae, Phenuiviridae, and Picornaviridae families. Metagenomic sequencing data was insufficient to determine the viral diversity of certain families due to the fragmented coverage of genomes and lack of suitable sequencing depth, as some viruses were detected from the analysis of reads-data only. Follow up conventional PCR assays targeting conserved gene regions for the Adenoviridae, Coronaviridae, and Herpesviridae families were used to confirm metagenomic data and generate additional sequences to determine genetic diversity. The complete coding genome of a MERS-related coronavirus was recovered with additional amplicon sequencing on the MiSeq platform. The new genome shared 97.2% overall nucleotide identity to a previous Neoromicia-associated MERS-related virus, also from South Africa. Conventional PCR analysis detected diverse adenovirus and herpesvirus sequences that were widespread throughout Neoromicia populations in South Africa. Furthermore, similar adenovirus sequences were detected within these populations throughout several years. With the exception of the coronaviruses, the study represents the first report of sequence data from several viral families within a Southern African insectivorous bat genus; highlighting the need for continued investigations in this regard.
Assuntos
Quirópteros/virologia , Infecções por Coronavirus/virologia , Genoma Viral/genética , Mamíferos/virologia , Zoonoses/virologia , Adenoviridae/genética , Adenoviridae/patogenicidade , Animais , Quirópteros/fisiologia , Biologia Computacional , Coronavirus/genética , Coronavirus/patogenicidade , Infecções por Coronavirus/veterinária , Trato Gastrointestinal/fisiologia , Trato Gastrointestinal/virologia , Variação Genética , Herpesviridae/genética , Herpesviridae/patogenicidade , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Metagenômica/métodos , Filogenia , Filogeografia , Análise de Sequência de DNA , África do SulRESUMO
Animal-associated microbiotas form complex communities, which play crucial functions for their host, including susceptibility to infections. Despite increasing attention to bats as reservoirs of zoonotic pathogens, their microbiota is poorly documented, especially for samples potentially implicated in pathogen transmission such as urine and saliva. Here, using low-biomass individual samples, we examined the composition and structure of bacterial communities excreted by insectivorous bats, focusing on three body habitats (saliva, urine and faeces). We show that niche specialisation occurs as bacterial community composition was distinct across body habitats with the majority of phylotypes being body habitat specific. Our results suggest that urine harbours more diverse bacterial communities than saliva and faeces and reveal potentially zoonotic bacteria such as Leptospira, Rickettsia, Bartonella and Coxiella in all body habitats. Our study emphasised that, in addition to the traditional use of gut-associated samples such as faeces, both urine and saliva are also of interest because of their diverse microbiota and the potential transmission of pathogenic bacteria. Our results represent a critical baseline for future studies investigating the interactions between microbiota and infection dynamics in bats.
Assuntos
Bactérias/isolamento & purificação , Quirópteros/microbiologia , Fezes/microbiologia , Microbiota , Saliva/microbiologia , Urina/microbiologia , África , Animais , Bactérias/classificação , Bartonella/isolamento & purificação , Coxiella/isolamento & purificação , Leptospira/isolamento & purificação , Rickettsia/isolamento & purificação , Zoonoses/microbiologia , Zoonoses/transmissãoRESUMO
The taxonomy of sub-Saharan small insectivore bats of the family Vespertilionidae is unresolved and currently five named species of the genus Neoromicia are recognized from southern Africa, with N. melckorum considered a synonym of N. capensis. Since several years, the name "N. cf. melckorum" has been used in the literature to designate an apparently undescribed and moderately large bodied vespertilionid bat known from different localities in southern and southeastern Africa. Using new data from molecular genetics, bacular morphology, and cranio-dental characters, we conclude that N. melckorum sensu stricto is indeed nested within N. capensis and obtain the needed evidence to formally describe "N. cf. melckorum", named herein as N. stanleyi sp. nov. On the basis of molecular and bacular evidence, N. stanleyi is found in Botswana, Zimbabwe, and Zambia, and using a combination of other characters is presumed to occur in northern South Africa and Malawi. Bayesian and maximum likelihood analyses based on 12S rRNA sequences indicate that it belongs to a clade containing four species of Neoromicia (N. capensis, N. malagasyensis, N. matroka, and N. robertsi) and Laephotis. Neoromicia stanleyi shows at least 3.2% nucleotide divergence from its closest relatives. It is larger in cranial characters than other members of the capensis group occurring in the southern portion of Africa, and a number of bacular characters distinguish N. stanleyi from N. capensis.
Assuntos
Quirópteros , África do Norte , África Austral , Animais , Teorema de Bayes , Malaui , Filogenia , África do Sul , Zâmbia , ZimbábueRESUMO
In addition to several emerging viruses, bats have been reported to host multiple bacteria but their zoonotic threats remain poorly understood, especially in Africa where the diversity of bats is important. Here, we investigated the presence and diversity of Bartonella and Rickettsia spp. in bats and their ectoparasites (Diptera and Siphonaptera) collected across South Africa and Swaziland. We collected 384 blood samples and 14 ectoparasites across 29 different bat species and found positive samples in four insectivorous and two frugivorous bat species, as well as their Nycteribiidae flies. Phylogenetic analyses revealed diverse Bartonella genotypes and one main group of Rickettsia, distinct from those previously reported in bats and their ectoparasites, and for some closely related to human pathogens. Our results suggest a differential pattern of host specificity depending on bat species. Bartonella spp. identified in bat flies and blood were identical supporting that bat flies may serve as vectors. Our results represent the first report of bat-borne Bartonella and Rickettsia spp. in these countries and highlight the potential role of bats as reservoirs of human bacterial pathogens.
Assuntos
Bartonella/fisiologia , Quirópteros/genética , Quirópteros/microbiologia , Comportamento Alimentar , Variação Genética , Parasitos/microbiologia , Rickettsia/fisiologia , Animais , DNA Bacteriano/análise , Essuatíni , Filogenia , África do SulRESUMO
Phenotypes of distantly related species may converge through adaptation to similar habitats and/or because they share biological constraints that limit the phenotypic variants produced. A common theme in bats is the sympatric occurrence of cryptic species that are convergent in morphology but divergent in echolocation frequency, suggesting that echolocation may facilitate niche partitioning, reducing competition. If so, allopatric populations freed from competition, could converge in both morphology and echolocation provided they occupy similar niches or share biological constraints. We investigated the evolutionary history of a widely distributed African horseshoe bat, Rhinolophus darlingi, in the context of phenotypic convergence. We used phylogenetic inference to identify and date lineage divergence together with phenotypic comparisons and ecological niche modelling to identify morphological and geographical correlates of those lineages. Our results indicate that R. darlingi is paraphyletic, the eastern and western parts of its distribution forming two distinct non-sister lineages that diverged ~9.7 Mya. We retain R. darlingi for the eastern lineage and argue that the western lineage, currently the sub-species R. d. damarensis, should be elevated to full species status. R. damarensis comprises two lineages that diverged ~5 Mya. Our findings concur with patterns of divergence of other co-distributed taxa which are associated with increased regional aridification between 7-5 Mya suggesting possible vicariant evolution. The morphology and echolocation calls of R. darlingi and R. damarensis are convergent despite occupying different biomes. This suggests that adaptation to similar habitats is not responsible for the convergence. Furthermore, R. darlingi forms part of a clade comprising species that are bigger and echolocate at lower frequencies than R. darlingi, suggesting that biological constraints are unlikely to have influenced the convergence. Instead, the striking similarity in morphology and sensory biology are probably the result of neutral evolutionary processes, resulting in the independent evolution of similar phenotypes.