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Gábor Á. Czirják - One of the best experts on this subject based on the ideXlab platform.
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species specific differences in toxoplasma gondii neospora caninum and besnoitia besnoiti seroprevalence in namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites (Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs (Acinonyx jubatus, n = 250) and leopards (Panthera pardus, n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). All but one carnivore species (bat-eared fox Otocyon megalotis, n = 4) were seropositive to T. gondii, with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions (Panthera leo). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest (Connochaetes taurinus). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas (Hyaena brunnea) and 2.6% (1/39) of black-backed jackals (Canis mesomelas). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
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Species-specific differences in Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti seroprevalence in Namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Background Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. Methods We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites ( Toxoplasma gondii , Neospora caninum and Besnoitia besnoiti ) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs ( Acinonyx jubatus , n = 250) and leopards ( Panthera pardus , n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). Results All but one carnivore species (bat-eared fox Otocyon megalotis , n = 4) were seropositive to T. gondii , with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions ( Panthera leo ). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest ( Connochaetes taurinus ). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas ( Hyaena brunnea ) and 2.6% (1/39) of black-backed jackals ( Canis mesomelas ). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Conclusions Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
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Feliform carnivores have a distinguished constitutive innate immune response.
Biology open, 2016Co-Authors: Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Jörg Melzheimer, Heribert Hofer, Gábor Á. CzirjákAbstract:Determining the immunological phenotype of endangered and threatened populations is important to identify those vulnerable to novel pathogens. Among mammals, members of the order Carnivora are particularly threatened by diseases. We therefore examined the constitutive innate immune system, the first line of protection against invading microbes, of six free-ranging carnivore species; the black-backed jackal (Canis mesomelas), the brown hyena (Hyena brunnea), the caracal (Caracal caracal), the cheetah (Acinonyx jubatus), the leopard (Panthera pardus) and the lion (Panthera leo) using a bacterial killing assay. The differences in immune responses amongst the six species were independent of their foraging behaviour, body mass or social organisation but reflected their phylogenetic relatedness. The bacterial killing capacity of black-backed jackals, a member of the suborder Caniformia, followed the pattern established for a wide variety of vertebrates. In contrast, the five representatives of the suborder Feliformia demonstrated a killing capacity at least an order of magnitude higher than any species reported previously, with a particularly high capacity in caracals and cheetahs. Our results suggest that the immunocompetence of threatened felids such as the cheetah has been underestimated and its assessment ought to consider both innate and adaptive components of the immune system.
Géraldine Veron - One of the best experts on this subject based on the ideXlab platform.
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Evolutionary history of Carnivora (Mammalia, Laurasiatheria) inferred from mitochondrial genomes.
PloS one, 2021Co-Authors: Alexandre Hassanin, Géraldine Veron, Anne Ropiquet, Bettine Jansen Van Vuuren, Alexis Lécu, Steven M. Goodman, Jibran Haider, Trung Thanh NguyenAbstract:The order Carnivora, which currently includes 296 species classified into 16 families, is distributed across all continents. The phylogeny and the timing of diversification of members of the order are still a matter of debate. Here, complete mitochondrial genomes were analysed to reconstruct the phylogenetic relationships and to estimate divergence times among species of Carnivora. We assembled 51 new mitogenomes from 13 families, and aligned them with available mitogenomes by selecting only those showing more than 1% of nucleotide divergence and excluding those suspected to be of low-quality or from misidentified taxa. Our final alignment included 220 taxa representing 2,442 mitogenomes. Our analyses led to a robust resolution of suprafamilial and intrafamilial relationships. We identified 21 fossil calibration points to estimate a molecular timescale for carnivorans. According to our divergence time estimates, crown carnivorans appeared during or just after the Early Eocene Climatic Optimum; all major groups of Caniformia (Cynoidea/Arctoidea; Ursidae; Musteloidea/Pinnipedia) diverged from each other during the Eocene, while all major groups of Feliformia (Nandiniidae; Feloidea; Viverroidea) diversified more recently during the Oligocene, with a basal divergence of Nandinia at the Eocene/Oligocene transition; intrafamilial divergences occurred during the Miocene, except for the Procyonidae, as Potos separated from other genera during the Oligocene.
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Phenotypic integration in feliform carnivores: Covariation patterns and disparity in hypercarnivores versus generalists.
Evolution; international journal of organic evolution, 2020Co-Authors: Margot Michaud, Géraldine Veron, Anne-claire FabreAbstract:The skeleton is a complex arrangement of anatomical structures that covary to various degrees depending on both intrinsic and extrinsic factors. Among the Feliformia, many species are characterized by predator lifestyles providing a unique opportunity to investigate the impact of highly specialized hypercarnivorous diet on phenotypic integration and shape diversity. To do so, we compared the shape of the skull, mandible, humerus, and femur of species in relation to their feeding strategies (hypercarnivorous vs. generalist species) and prey preference (predators of small vs. large prey) using three-dimensional geometric morphometric techniques. Our results highlight different degrees of morphological integration in the Feliformia depending on the functional implication of the anatomical structure, with an overall higher covariation of structures in hypercarnivorous species. The skull and the forelimb are not integrated in generalist species, whereas they are integrated in hypercarnivores. These results can potentially be explained by the different feeding strategies of these species. Contrary to our expectations, hypercarnivores display a higher disparity for the skull than generalist species. This is probably due to the fact that a specialization toward high-meat diet could be achieved through various phenotypes. Finally, humeri and femora display shape variations depending on relative prey size preference. Large species feeding on large prey tend to have robust long bones due to higher biomechanical constraints.
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Evolutionary history of Carnivora (Mammalia, Laurasiatheria) inferred from mitochondrial genomes
2020Co-Authors: Alexandre Hassanin, Géraldine Veron, Anne Ropiquet, Bettine Jansen Van Vuuren, Alexis Lécu, Steven M. Goodman, Jibran Haider, Trung Thanh NguyenAbstract:Abstract The order Carnivora, which currently includes 296 species classified into 16 families, is distributed across all continents. The phylogeny and the timing of diversifications are still a matter of debate. Here, complete mitochondrial genomes were analysed to reconstruct the phylogenetic relationships and to estimate divergence times among species of Carnivora. We assembled 51 new mitogenomes from 13 families, and aligned them with available mitogenomes by selecting only those showing more than 1% of nucleotide divergence and excluding those suspected to be of low-quality or from misidentified taxa. Our final alignment included 220 taxa representing 2,442 mitogenomes. Our analyses led to a robust resolution of suprafamilial and intrafamilial relationships. We identified 22 fossil calibration points to estimate a molecular timescale for carnivorans. According to our divergence time estimates, crown carnivorans appeared during or just after the Early Eocene Climatic Optimum; all major groups of Caniformia (Cynoidea/Arctoidea; Ursidae; Musteloidea/Pinnipedia) diverged from each other during the Eocene, while all major groups of Feliformia (Nandiniidae; Feloidea; Viverroidea) diversified more recently during the Oligocene, with a basal divergence of Nandinia at the Eocene/Oligocene transition; intrafamilial divergences occurred during the Miocene, except for the Procyonidae, as Potos separated from other genera during the Oligocene.
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Mosaics of convergences and noise in morphological phylogenies: what's in a viverrid-like carnivoran?
Systematic biology, 2005Co-Authors: Philippe Gaubert, W. Chris Wozencraft, Pedro Cordeiro-estrela, Géraldine VeronAbstract:Adaptive convergence in morphological characters has not been thoroughly investigated, and the processes by which phylogenetic relationships may be misled by morphological convergence remains unclear. We undertook a case study on the morphological evolution of viverrid-like Feliformians (Nandinia, Cryptoprocta, Fossa, Eupleres, Prionodon) and built the largest morphological matrix concerning the suborder Feliformia to date. A total of 349 characters grouped into four anatomical partitions were used for all species of Viverridae and viverrid-like taxa plus representatives of the Felidae, Hyaenidae, Herpestidae, and one Malagasy mongoose. Recent molecular phylogenetic analyses suggest that viverrid-like morphotypes appeared independently at least three times during Feliformian evolution. We thus used a synthetic molecular tree to assess morphological evolutionary patterns characterizing the viverrid-like taxa. We examined phylogenetic signal, convergence and noise in morphological characters using (a) tree-length distribution (g1), (b) partitioned Bremer support, (c) RI values and their distribution, (d) respective contributions of diagnostic synapomorphies at the nodes for each partition, (e) patterns of shared convergences among viverrid-like taxa and other Feliformian lineages, (f) tree-length differences among alternative hypotheses, and (g) the successive removal of convergent character states from the original matrix. In addition, the lability of complex morphological structures was assessed by mapping them onto the synthetic molecular tree. The unconstrained morphological analysis yielded phylogenetic groupings that closely reflected traditional classification. The use of a synthetic molecular tree (constraint) combined with our thorough morphological investigations revealed the mosaics of convergences likely to have contributed to part of the historical uncertainty over viverrid classification. It also showed that complex morphological structures could be subjected to reversible evolutionary trends. The morphological matrix proved useful in characterizing several Feliformian clades with diagnostic synapomorphies. These results support the removal from the traditionally held Viverridae of several viverrid-like taxa into three distinct families: Nandiniidae (Nandinia), Prionodontidae (Prionodon), and the newly defined Eupleridae (including Cryptoprocta, Fossa, Eupleres plus all "mongoose-like" Malagasy taxa). No clearly "phylogenetically misleading" data subsets could be identified, and the great majority of morphological convergences appeared to be nonadaptive. The multiple approaches used in this study revealed that the most disruptive element with regards to morphological phylogenetic reconstruction was noise, which blured the expression of phylogenetic signal. This study demonstrates the crucial need to consider independent (molecular) phylogenies in order to produce reliable evolutionary hypotheses and should promote a new approach to the definition of morphological characters in mammals. [Constrained analysis; convergence; evolutionary scenario; Feliformia; morphology; noise; phylogenetic signal; phylogeny; Viverridae.].
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First molecular evidence for reassessing phylogenetic affinities between genets (Genetta) and the enigmatic genet-like taxa Osbornictis, Poiana and Prionodon (Carnivora, Viverridae)
Zoologica Scripta, 2004Co-Authors: Philippe Gaubert, Michel Tranier, Annesophie Delmas, Marc Colyn, Géraldine VeronAbstract:The subfamily Viverrinae is a composite group of carnivores comprising the large and plantigrade terrestrial civets (Civettictis, Viverricula and Viverra) and the slender and generally more arboreal genets and genet-like taxa (Genetta, Prionodon, Poiana, Osbornictis), both having Asiatic and African representatives. The problematic phylogenetic relationships between genets and genet-like taxa are addressed for the first time from a molecular perspective through complete cytochrome b gene sequences. We used a large taxonomic sample set including some very rare and crucial species such as Osbornictis piscivora, Poiana richardsonii (museum specimen material) and Genetta johnstoni. The results from parsimony, distance and maximum likelihood analyses do not support the monophyly of the Viverrinae and contradict previous morphological hypotheses. The Asiatic linsangs (Prionodon spp.) are excluded from the Viverrinae and represent either a basal Feliformia or Viverridae. The other genet-like taxa constitute a strongly supported monophyletic African group, in which the African linsang (represented by Poiana richardsonii) is a sister group to the genets. The aquatic genet Osbornictis piscivora is included within the latter clade, and the genus Osbornictis should be considered a junior synonym of Genetta. African and Asiatic terrestrial civets are monophyletic, but their phylogenetic affinities with the genet-like clade are inconclusive using our data set. On the basis of our molecular results, morphological convergences and adaptations to peculiar habitats and ways of life within genets and genet-like taxa are discussed.
Anne Seltmann - One of the best experts on this subject based on the ideXlab platform.
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Species-specific differences in Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti seroprevalence in Namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Background Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. Methods We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites ( Toxoplasma gondii , Neospora caninum and Besnoitia besnoiti ) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs ( Acinonyx jubatus , n = 250) and leopards ( Panthera pardus , n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). Results All but one carnivore species (bat-eared fox Otocyon megalotis , n = 4) were seropositive to T. gondii , with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions ( Panthera leo ). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest ( Connochaetes taurinus ). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas ( Hyaena brunnea ) and 2.6% (1/39) of black-backed jackals ( Canis mesomelas ). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Conclusions Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
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species specific differences in toxoplasma gondii neospora caninum and besnoitia besnoiti seroprevalence in namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites (Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs (Acinonyx jubatus, n = 250) and leopards (Panthera pardus, n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). All but one carnivore species (bat-eared fox Otocyon megalotis, n = 4) were seropositive to T. gondii, with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions (Panthera leo). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest (Connochaetes taurinus). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas (Hyaena brunnea) and 2.6% (1/39) of black-backed jackals (Canis mesomelas). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
Gereon Schares - One of the best experts on this subject based on the ideXlab platform.
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Species-specific differences in Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti seroprevalence in Namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Background Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. Methods We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites ( Toxoplasma gondii , Neospora caninum and Besnoitia besnoiti ) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs ( Acinonyx jubatus , n = 250) and leopards ( Panthera pardus , n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). Results All but one carnivore species (bat-eared fox Otocyon megalotis , n = 4) were seropositive to T. gondii , with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions ( Panthera leo ). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest ( Connochaetes taurinus ). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas ( Hyaena brunnea ) and 2.6% (1/39) of black-backed jackals ( Canis mesomelas ). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Conclusions Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
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species specific differences in toxoplasma gondii neospora caninum and besnoitia besnoiti seroprevalence in namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites (Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs (Acinonyx jubatus, n = 250) and leopards (Panthera pardus, n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). All but one carnivore species (bat-eared fox Otocyon megalotis, n = 4) were seropositive to T. gondii, with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions (Panthera leo). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest (Connochaetes taurinus). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas (Hyaena brunnea) and 2.6% (1/39) of black-backed jackals (Canis mesomelas). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
Ortwin Aschenborn - One of the best experts on this subject based on the ideXlab platform.
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species specific differences in toxoplasma gondii neospora caninum and besnoitia besnoiti seroprevalence in namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites (Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs (Acinonyx jubatus, n = 250) and leopards (Panthera pardus, n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). All but one carnivore species (bat-eared fox Otocyon megalotis, n = 4) were seropositive to T. gondii, with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions (Panthera leo). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest (Connochaetes taurinus). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas (Hyaena brunnea) and 2.6% (1/39) of black-backed jackals (Canis mesomelas). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
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Species-specific differences in Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti seroprevalence in Namibian wildlife
Parasites & Vectors, 2020Co-Authors: Anne Seltmann, Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Gereon Schares, Gábor Á. CzirjákAbstract:Background Knowledge about parasitic infections is crucial information for animal health, particularly of free-ranging species that might come into contact with livestock and humans. Methods We investigated the seroprevalence of three tissue-cyst-forming apicomplexan parasites ( Toxoplasma gondii , Neospora caninum and Besnoitia besnoiti ) in 506 individuals of 12 wildlife species in Namibia using in-house enzyme linked immunosorbent assays (indirect ELISAs applying purified antigens) for screening and immunoblots as confirmatory tests. We included six species of the suborder Feliformia, four species of the suborder Caniformia and two species of the suborder Ruminantia. For the two species for which we had most samples and life-history information, i.e. cheetahs ( Acinonyx jubatus , n = 250) and leopards ( Panthera pardus , n = 58), we investigated T. gondii seroprevalence in relation to age class, sex, sociality (solitary, mother-offspring group, independent sibling group, coalition group) and site (natural habitat vs farmland). Results All but one carnivore species (bat-eared fox Otocyon megalotis , n = 4) were seropositive to T. gondii , with a seroprevalence ranging from 52.4% (131/250) in cheetahs to 93.2% (55/59) in African lions ( Panthera leo ). We also detected antibodies to T. gondii in 10.0% (2/20) of blue wildebeest ( Connochaetes taurinus ). Adult cheetahs and leopards were more likely to be seropositive to T. gondii than subadult conspecifics, whereas seroprevalence did not vary with sex, sociality and site. Furthermore, we measured antibodies to N. caninum in 15.4% (2/13) of brown hyenas ( Hyaena brunnea ) and 2.6% (1/39) of black-backed jackals ( Canis mesomelas ). Antibodies to B. besnoiti were detected in 3.4% (2/59) of African lions and 20.0% (4/20) of blue wildebeest. Conclusions Our results demonstrate that Namibian wildlife species were exposed to apicomplexan parasites at different prevalences, depending on parasite and host species. In addition to serological work, molecular work is also needed to better understand the sylvatic cycle and the clear role of wildlife in the epidemiology of these parasites in southern Africa.
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Feliform carnivores have a distinguished constitutive innate immune response.
Biology open, 2016Co-Authors: Sonja K. Heinrich, Bettina Wachter, Ortwin Aschenborn, Susanne Thalwitzer, Jörg Melzheimer, Heribert Hofer, Gábor Á. CzirjákAbstract:Determining the immunological phenotype of endangered and threatened populations is important to identify those vulnerable to novel pathogens. Among mammals, members of the order Carnivora are particularly threatened by diseases. We therefore examined the constitutive innate immune system, the first line of protection against invading microbes, of six free-ranging carnivore species; the black-backed jackal (Canis mesomelas), the brown hyena (Hyena brunnea), the caracal (Caracal caracal), the cheetah (Acinonyx jubatus), the leopard (Panthera pardus) and the lion (Panthera leo) using a bacterial killing assay. The differences in immune responses amongst the six species were independent of their foraging behaviour, body mass or social organisation but reflected their phylogenetic relatedness. The bacterial killing capacity of black-backed jackals, a member of the suborder Caniformia, followed the pattern established for a wide variety of vertebrates. In contrast, the five representatives of the suborder Feliformia demonstrated a killing capacity at least an order of magnitude higher than any species reported previously, with a particularly high capacity in caracals and cheetahs. Our results suggest that the immunocompetence of threatened felids such as the cheetah has been underestimated and its assessment ought to consider both innate and adaptive components of the immune system.
