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1.
Artigo em Inglês | MEDLINE | ID: mdl-38717050

RESUMO

Background: While the influence of landscape and microclimatic conditions on tick populations is well-documented, there remains a gap in more specific data regarding their relationship to rewilding efforts with large herbivore activity. Objective: This pilot study, spanning from 2019 to 2021, explores the effects of naturalistic grazing by large semi-wild ungulates on tick abundance in the Milovice Reserve, Czechia. Methods: Tick collection was observed using flagging techniques at two distinct sites of rewilding area: one grazed, actively utilized by animals involved in the rewilding project, and one ungrazed, left fallow in neighboring areas utilized only by wild animals. Transects, each measuring 150 m in length and 5 m in width (750 m2), were established at these two sampling locations from March to September between 2019 and 2021. To minimize potential bias resulting from tick movement, a 300 m buffer zone separated the two sites. Data analysis employed a generalized estimating equations (GEE) model with negative binomial regression. The study assessed potential variations in tick abundance between selected transects, considering factors such as plant cover seasonality, temperature, and humidity. Results: During the collection periods, we gathered 586 live ticks, with 20% found in grazed areas and 80% in ungrazed areas. Notably, tick abundance was significantly higher in ungrazed areas. Peaks in tick abundance occurred in both grazed and ungrazed areas during spring, particularly in April. However, tick numbers declined more rapidly in grazed areas. Microclimatic variables like temperature and humidity did not significantly impact tick abundance compared to landscape management and seasonal factors. Conclusion: Rewilding efforts, particularly natural grazing by large ungulates, influence tick abundance and distribution. This study provides empirical data on tick ecology in rewilded areas, highlighting the importance of landscape management and environmental factors in tick management and conservation. Trophic rewilding plays a crucial role in shaping ecosystems and tick population dynamics in transformed landscapes.

2.
Biol Lett ; 17(6): 20210166, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34129800

RESUMO

Severe Perkinsea infection is an emerging disease of amphibians, specifically tadpoles. Disease presentation correlates with liver infections of a subclade of Perkinsea (Alveolata) protists, named Pathogenic Perkinsea Clade (PPC). Tadpole mortality events associated with PPC infections have been reported across North America, from Alaska to Florida. Here, we investigate the geographic and host range of PPC associations in seemingly healthy tadpoles sampled from Panama, a biogeographic provenance critically affected by amphibian decline. To complement this work, we also investigate a mortality event among Hyla arborea tadpoles in captive-bred UK specimens. PPC SSU rDNA was detected in 10 of 81 Panama tadpoles tested, and H. arborea tadpoles from the UK. Phylogenies of the Perkinsea SSU rDNA sequences demonstrate they are highly similar to PPC sequences sampled from mortality events in the USA, and phylogenetic analysis of tadpole mitochondrial SSU rDNA demonstrates, for the first time, PPC associations in diverse hylids. These data provide further understanding of the biogeography and host range of this putative pathogenic group, factors likely to be important for conservation planning.


Assuntos
Larva , Alaska , Animais , Florida , América do Norte , Filogenia
3.
Ecol Evol ; 11(10): 5468-5483, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34026021

RESUMO

The border region between Austria, the Czech Republic, and Germany harbors the most south-western occurrence of moose in continental Europe. The population originated in Poland, where moose survived, immigrated from former Soviet Union or were reintroduced after the Second World War expanded west- and southwards. In recent years, the distribution of the nonetheless small Central European population seems to have declined, necessitating an evaluation of its current status. In this study, existing datasets of moose observations from 1958 to 2019 collected in the three countries were combined to create a database totaling 771 records (observations and deaths). The database was then used to analyze the following: (a) changes in moose distribution, (b) the most important mortality factors, and (c) the availability of suitable habitat as determined using a maximum entropy approach. The results showed a progressive increase in the number of moose observations after 1958, with peaks in the 1990s and around 2010, followed by a relatively steep drop after 2013. Mortality within the moose population was mostly due to human interactions, including 13 deadly wildlife-vehicle collisions, particularly on minor roads, and four animals that were either legally culled or poached. Our habitat model suggested that higher altitudes (ca. 700-1,000 m a.s.l.), especially those offering wetlands, broad-leaved forests and natural grasslands, are the preferred habitats of moose whereas steep slopes and areas of human activity are avoided. The habitat model also revealed the availability of large core areas of suitable habitat beyond the current distribution, suggesting that habitat was not the limiting factor explaining the moose distribution in the study area. Our findings call for immediate transboundary conservation measures to sustain the moose population, such as those aimed at preventing wildlife-vehicle collisions and illegal killings. Infrastructure planning and development activities must take into account the habitat requirements of moose.

4.
BMC Ecol Evol ; 21(1): 73, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33931041

RESUMO

BACKGROUND: Refaunation/rewilding by large ungulates represents a cost-efficient approach to managing natural biotopes and may be particularly useful for areas whose biodiversity depends on disturbance dynamics and is imperilled by successional changes. To study impacts of refaunation on invertebrates, we focused on butterflies inhabiting the former military training range Milovice, Czech Republic, refaunated since 2015 by a combination of Exmoor pony ("wild" horse), Tauros cattle ("aurochs"), and European wisent. METHODS: We analysed butterfly presence-absence patterns immediately after the military use termination (early 1990s), prior to the refaunation (2009), and after it (2016-19); and current abundance data gained by monitoring butterflies at refaunated and neglected plots. We used correspondence analysis for the presence-absence comparison and canonical correspondence analysis for the current monitoring, and related results of both ordination methods to the life history and climatic traits, and conservation-related attributes, of recorded butterflies. RESULTS: Following the termination of military use, several poorly mobile species inclining towards oceanic climates were lost. Newly gained are mobile species preferring warmer continental conditions. The refaunated plots hosted higher butterfly species richness and abundances. Larger-bodied butterflies developing on coarse grasses and shrubs inclined towards neglected plots, whereas refaunated plots supported smaller species developing on small forbs. CONCLUSION: The changes in species composition following the cessation of military use were attributable to successional change, coupled with changes in species pool operating at larger scales. By blocking succession, large ungulates support butterflies depending on competitively poor plants. Restoring large ungulates populations represents a great hope for conserving specialised insects, provided that settings of the projects, and locally adapted ungulate densities, do not deplete resources for species with often contrasting requirements.


Assuntos
Borboletas , Militares , Animais , Biodiversidade , Bovinos , República Tcheca , Cavalos , Humanos , Plantas
6.
Eur J Protistol ; 73: 125668, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31927140

RESUMO

The Javan ferret-badger Melogale orientalis (Carnivora: Mustelidae: Helictidinae) is a small carnivore endemic to Indonesia. In the family Mustelidae, 10 Eimeria, 12 Cystoisopora, one Isospora, and one Hammondia species are known, but no eimeriid coccidia has been yet described in the subfamily Helictinidae (ferret badgers). Coproscopic examination of Javan ferret-badgers imported into the Czech Republic revealed the presence of coccidian oocysts. Sporulated oocysts differ from other Eimeria known in the family Mustelidae by their small size (12.4-16.1 × 10.4-13.4 µm) and ovoidal shape. Morphological data and phylogenetic analyses of 18S rRNA and COI genes indicated a new species of Eimeria found in faecal samples of Javan ferret badgers. The species is described as E. melogale n. sp.


Assuntos
Eimeria/classificação , Mustelidae/parasitologia , Filogenia , Animais , República Tcheca , Eimeria/citologia , Eimeria/genética , Fezes/parasitologia , Oocistos/citologia , RNA Ribossômico 18S/genética , Especificidade da Espécie
7.
Sci Rep ; 9(1): 19907, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31857665

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

8.
Sci Rep ; 9(1): 15748, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673053

RESUMO

Cryptic genetic diversity and erroneous morphological species determination represent frequent problems in biodiversity research. Here, examination of 138 specimens of Synodontis (Mochokidae, Siluriformes) from the Nile River and Lake Turkana revealed the presence of both S. schall-like and S. frontosus-like morphotypes, with a phenotypic gradient between them. We concluded phylogenetic and population genetic analyses based on two mitochondrial and one nuclear marker including 131 coxI (565 bp), 96 cytb (973 bp) and 19 RAG2 (896 bp) sequences from the Nile-Turkana population, plus additional GenBank data of Synodontis spp. Whilst nuclear data were inconclusive, mitochondrial sequences suggested that both morphotypes and intermediate forms are conspecific. The results imply probable synonymy of S. frontosus with S. schall. Conversely, a strong biogeographical signal was revealed among widely distributed and supposedly conspecific S. schall-like catfish of the Nilo-Sudanian ichthyological province. Synodontis schall sensu stricto (=Eastern clade), as defined by type locality in the Nile, is apparently restricted to the eastern part of the Nilo-Sudanian ichthyological province (e.g. Nile, Turkana, Chad). Synodontis schall Western clade (Senegambia, Niger, Chad) most probably represents a cryptic taxon, unrecognized thus far due to the absence of distinctive morphological differences.


Assuntos
Biodiversidade , Peixes-Gato/genética , Animais , Teorema de Bayes , Peixes-Gato/classificação , Citocromos b/classificação , Citocromos b/genética , Complexo IV da Cadeia de Transporte de Elétrons/classificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genética Populacional , Haplótipos , Filogenia
9.
Proc Natl Acad Sci U S A ; 116(41): 20382-20387, 2019 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-31548391

RESUMO

Biodiversity loss is one major outcome of human-mediated ecosystem disturbance. One way that humans have triggered wildlife declines is by transporting disease-causing agents to remote areas of the world. Amphibians have been hit particularly hard by disease due in part to a globally distributed pathogenic chytrid fungus (Batrachochytrium dendrobatidis [Bd]). Prior research has revealed important insights into the biology and distribution of Bd; however, there are still many outstanding questions in this system. Although we know that there are multiple divergent lineages of Bd that differ in pathogenicity, we know little about how these lineages are distributed around the world and where lineages may be coming into contact. Here, we implement a custom genotyping method for a global set of Bd samples. This method is optimized to amplify and sequence degraded DNA from noninvasive skin swab samples. We describe a divergent lineage of Bd, which we call BdASIA3, that appears to be widespread in Southeast Asia. This lineage co-occurs with the global panzootic lineage (BdGPL) in multiple localities. Additionally, we shed light on the global distribution of BdGPL and highlight the expanded range of another lineage, BdCAPE. Finally, we argue that more monitoring needs to take place where Bd lineages are coming into contact and where we know little about Bd lineage diversity. Monitoring need not use expensive or difficult field techniques but can use archived swab samples to further explore the history-and predict the future impacts-of this devastating pathogen.


Assuntos
Anfíbios/microbiologia , Quitridiomicetos , Micoses/veterinária , Animais , Quitridiomicetos/genética , Saúde Global , Micoses/epidemiologia , Micoses/microbiologia
10.
Eur J Protistol ; 66: 77-85, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30179769

RESUMO

Philippine tarsier (Tarsius syrichta) is a small nocturnal primate from the Philippines. Little is known about tarsier parasites, including coccidia (Apicomplexa: Eimeriidae), a highly prevalent parasitic protist group in all vertebrate classes. Only 7 valid species of the genus Eimeria, seven species of Isospora and 5 species of Cyclospora have been described in Primates. This study extends the number of coccidia known in primates by two new species obtained from faeces of Philippine tarsiers from Bohol Island. The newly described Eimeria syrichta n. sp. and Eimeria boholensis n. sp. differ morphologically from each other as well as from other coccidia reported from primates. Partial DNA sequences of three genes were obtained from oocysts of E. syrichta n. sp. and E. boholensis n. sp., and formed clusters according to their host specificity; however, there are no other sequentional data of coccidia from primates, except for the genus Cyclospora, which clusters inside the chicken eimerians, and Cystoisospora belli, which is phylogenetically related to Sarcocystidae. More molecular data on coccidia infecting primates are needed for further discussion.


Assuntos
Eimeria/classificação , Filogenia , Tarsiidae/parasitologia , Animais , DNA de Protozoário/genética , Eimeria/fisiologia , Especificidade de Hospedeiro , Filipinas , Especificidade da Espécie
11.
Artigo em Inglês | MEDLINE | ID: mdl-29063858

RESUMO

Twenty species (sixteen adult and four larval) of parasitic nematodes belonging to the Ascaridoidea, Camallanoidea, Cosmocercoidea, Dioctophymatoidea, Habronematoidea, Oxyuroidea, Seuratoidea, and Thelazioidea were collected from freshwater fishes of the Congo River basin in the Democratic Republic of the Congo and the Central African Republic in 2008 and 2012, respectively. Based on light and scanning electron microscopical examination, many species are redescribed in detail. This material also contained four previously unknown species, Labeonema longispiculatum sp. n. from Synodontis acanthomias Boulenger, Gendria longispiculata sp. n. from Schilbe grenfelli (Boulenger), G. sanghaensis sp. n. from Schilbe marmoratus Boulenger, and Cucullanus congolensis sp. n. from Auchenoglanis occidentalis (Valenciennes). The new species L. longispiculatum is mainly characterised by conspicuously long (210-228 µm) spicules, approximately twice as long as those in other congeners, the length (45-48 µm) of the gubernaculum and the host family (Mochokidae), whereas G. longispiculata by very long (1.2 mm) spicules, the shape of the oesophagus and cephalic vesicle, distribution of postanal papillae and the host family (Schilbeidae). Main characteristic features of G. sanghaensis are the presence of a hexagonal oral aperture surrounded by lip-like structures, the posterior portion of the oesophagus moderately expanded, spicules and the gubernaculum 414-438 µm and 54-57 µm long, respectively, deirids located at the level of the posterior end of the oesophagus and the absence of cervical alae. Cucullanus congolensis differs from congeneric species parasitising African freshwater and brackish-water fishes mainly in the absence of a ventral precloacal sucker and lateral preanal papillae, the presence of a large median precloacal papilla-like formation, spicules 480-489 µm long and the location of the excretory pore in the region of the oesophago-intestinal junction. Chabaudus Inglis et Ogden, 1965 is considered a junior synonym of Gendria Baylis, 1930 and, consequently, species listed in the former genus are transferred to the latter as G. alaini (Alfonso-Roque, 1981) comb. n., G. chabaudi (Inglis et Ogden, 1965) comb. n., G. dehradunensis (Rizvi, Bursey et Maity, 2016) comb. n., G. thysi (Puylaert, 1970) comb. n. and G. williamsi (Puylaert, 1970) comb. n. The findings represent many new host and geographical records.


Assuntos
Doenças dos Peixes/parasitologia , Nematoides/classificação , Infecções por Nematoides/veterinária , Animais , República Centro-Africana , República Democrática do Congo , Feminino , Peixes , Água Doce/parasitologia , Intestinos/parasitologia , Masculino , Microscopia Eletrônica de Varredura/veterinária , Nematoides/ultraestrutura , Infecções por Nematoides/parasitologia , Rios
12.
PLoS One ; 12(4): e0175286, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28394904

RESUMO

Biogeographical and ecological barriers strongly affect the course of micro-evolutionary processes in free living organisms. Here we assess the impact of a recently emerged barrier on populations of limnic fauna. Genetic diversity and population structure in a host-parasite system (Wenyonia virilis tapeworm, Synodontis schall catfish) are analyzed in the recently divided Turkana and Nile basins. The two basins, were repeatedly connected during the Holocene wet/dry climatic oscillations, following late Pleistocene dessication of the Turkana basin. Mitochondrial DNA sequences for cytochrome oxidase I gene (cox I) and a whole genome scanning method-amplified fragment length polymorphism (AFLP) were employed. A total of 347 cox I sequences (representing 209 haplotypes) and 716 AFLP fragments, as well as 120 cox I sequences (20 haplotypes) and 532 AFLP fragments were obtained from parasites and hosts, respectively. Although results indicate that host and parasite populations share some formative traits (bottlenecks, Nilotic origin), their population histories/patterns differ markedly. Mitochondrial analysis revealed that parasite populations evolve significantly faster and show remarkably higher genetic variability. Analyses of both markers confirmed that the parasites undergo lineage fission, forming new clusters specific for either freshwater or saline parts of Lake Turkana. In congruence with the geological history, these clusters apparently indicate multiple colonisations of Lake Turkana from the Nile. In contrast, the host population pattern indicates fusion of different colonisation waves. Although fish host populations remain connected, saline habitats in Lake Turkana (absent in the Nile), apparently pose a barrier to the gene flow in the parasite, possibly due to its multihost lifecycle, which involves freshwater annelids. Despite partially corroborating mitochondrial results, AFLP data was not sufficiently informative for analyzing populations with recently mixed biogeographic histories.


Assuntos
Peixes-Gato/genética , Peixes-Gato/parasitologia , Cestoides/genética , Evolução Molecular , Ambientes Extremos , Interações Hospedeiro-Parasita/genética , Animais , Infecções por Cestoides/genética , Infecções por Cestoides/parasitologia , Infecções por Cestoides/veterinária , DNA Mitocondrial , Ecossistema , Complexo IV da Cadeia de Transporte de Elétrons/genética , Doenças dos Peixes/genética , Doenças dos Peixes/parasitologia , Haplótipos , Proteínas de Helminto/genética , Quênia , Lagos , Modelos Teóricos , Filogenia , Polimorfismo Genético , Águas Salinas
13.
Parasitology ; 144(8): 1016-1025, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28274296

RESUMO

Syngamid strongylids of the genus Mammomonogamus undoubtedly belong among the least known nematodes with apparent zoonotic potential and the real diversity of the genus remains hard to evaluate without extensive molecular data. Eggs of Mammomonogamus sp. are frequently found in feces of African forest elephants (Loxodonta cyclotis) and western lowland gorillas (Gorilla gorilla gorilla) in Dzanga-Sangha Protected Areas. Using sedimentation-based coproscopic techniques, we found the eggs of Mammomonogamus in 19·7% elephant and 54·1% gorilla fecal samples with 8-55 and 1-24 eggs per gram of fecal sediment for elephants and gorillas, respectively. We used a combination of light microscopy, scanning electron microscopy and analysis of cytochrome c oxidase subunit I (cox1) and a partial sequence of 18S rDNA isolated from single eggs to test the hypothesis of possible Mammomonogamus conspecificity in gorillas and elephants. Whereas 18S rDNA sequences were identical in both gorillas and elephants, we distinguished seven different haplotypes within the cox1. Two haplotypes were found in both gorillas and elephants suggesting sharing of Mammomonogamus. Assignment of the parasite to M. loxodontis is proposed. Provided sequences represent the first genomic data on Mammomonogamus spp.


Assuntos
Doenças dos Símios Antropoides/epidemiologia , Elefantes , Gorilla gorilla , Infecções por Strongylida/veterinária , Strongyloidea/fisiologia , Animais , Doenças dos Símios Antropoides/parasitologia , República Centro-Africana/epidemiologia , DNA de Helmintos/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Proteínas de Helminto/genética , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Masculino , Filogenia , Prevalência , RNA Ribossômico 18S/genética , Análise de Sequência de DNA/veterinária , Infecções por Strongylida/epidemiologia , Infecções por Strongylida/parasitologia , Strongyloidea/classificação , Strongyloidea/genética
14.
Syst Parasitol ; 93(9): 927-933, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27743240

RESUMO

The genus Megistacantha Golvan, 1960 was originally described as monotypic with Megistacantha horridum (Lühe, 1912) from a mormyrid fish in Africa as its type- and only species. This species was described from one female specimen, but no description of the male was provided. In this study, the male of M. horridum is described for the first time. In addition, a new species, Megistacantha sanghaensis n. sp., is described from the Cornish jack Mormyrops anguilloides L., a mormyrid fish from the River Sangha, Dzanga-Sangha Protected Areas, Central African Republic. The diagnosis of Megistacantha Golvan, 1960 is amended and a key to its two species is provided.


Assuntos
Acantocéfalos/classificação , Peixe Elétrico/parasitologia , Acantocéfalos/anatomia & histologia , Animais , República Centro-Africana , Feminino , Masculino , Rios , Especificidade da Espécie
15.
Environ Microbiol Rep ; 8(5): 675-679, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27119160

RESUMO

Amphibians are in decline as a result of habitat destruction, climate change and infectious diseases. Tadpoles are thought susceptible to infections because they are dependent on only an innate immune system (e.g. macrophages). This is because the frog adaptive immune system does not function until later stages of their life cycle. In 1920, Nöller described a putative infectious agent of tadpoles named Nematopsis temporariae, which he putatively assigned to gregarine protists (Apicomplexa). Here, we identify a gregarine infection of tadpoles using both microscopy and ribosomal DNA sequencing of three different frog species (Rana temporaria, R. dalmatina, and Hyla arborea). We show that this protist lineage belongs to the subclass Gregarinasina Dufour 1828 and is regularly present in macrophages located in liver sinusoids of tadpoles, confirming the only known case of a gregarine infection of a vertebrate.

16.
Parasit Vectors ; 9: 13, 2016 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-26754529

RESUMO

BACKGROUND: Myxozoans are metazoan parasites whose traditional spore morphology-based taxonomy conflicts DNA based phylogenies. Freshwater species of the genus Hoferellus are parasites of the excretory system, with several members infecting food and ornamental fish species, as well as amphibians. This study aims to increase our understanding of their molecular diversity and development, aspects about which little is known, and to generate a molecular diagnostic tool to discriminate between different pathogenic and non-pathogenic Hoferellus spp. METHODS: SSU and ITS rDNA phylogeny, along with morphological descriptions using light and electron microscopy were used to identify and characterize Hoferellus species collected from the urinary system of fishes and frogs. A PCR-based diagnostic assay was designed to differentiate between cryptic Hoferellus spp in cyprinid fishes commonly cultured in Central Europe. RESULTS: Our phylogenetic results separate the species of Hoferellus into two phylogenetic sublineages which are indistinguishable on the basis of generic morphological traits: 1) The Hoferellus sensu stricto sublineage, which is composed of the type species Hoferellus cyprini, Hoferellus carassii and a cryptic species, Hoferellus sp. detected only molecularly in common carp. 2) The Hoferellus sensu lato sublineage into which the new species we described in this study, Hoferellus gnathonemi sp. n. from the kidney of the elephantnose fish and Hoferellus anurae from reed frogs, are placed together with Hoferellus gilsoni previously sequenced from European eel. Apart from phylogenetic analyses, we also provide novel ultrastructural data on the phagocytotic nature of some Hoferellus plasmodia and on the elusive intracellular stages ascribed to the presporogonic development of this genus. CONCLUSIONS: We provide molecular evidence of the polyphyly of the genus Hoferellus and provide novel morphological details of its members. Based on the presented data, we revise and propose emendation of the genus Hoferellus.


Assuntos
Anuros/parasitologia , Doenças dos Peixes/parasitologia , Myxozoa/classificação , Doenças Parasitárias em Animais/parasitologia , Animais , Sequência de Bases , Cyprinidae , DNA Ribossômico/química , DNA Ribossômico/genética , Rim/patologia , Masculino , Dados de Sequência Molecular , Myxozoa/genética , Myxozoa/isolamento & purificação , Myxozoa/ultraestrutura , Filogenia , Análise de Sequência de DNA/veterinária
17.
Proc Natl Acad Sci U S A ; 112(34): E4743-51, 2015 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-26261337

RESUMO

The decline of amphibian populations, particularly frogs, is often cited as an example in support of the claim that Earth is undergoing its sixth mass extinction event. Amphibians seem to be particularly sensitive to emerging diseases (e.g., fungal and viral pathogens), yet the diversity and geographic distribution of infectious agents are only starting to be investigated. Recent work has linked a previously undescribed protist with mass-mortality events in the United States, in which infected frog tadpoles have an abnormally enlarged yellowish liver filled with protist cells of a presumed parasite. Phylogenetic analyses revealed that this infectious agent was affiliated with the Perkinsea: a parasitic group within the alveolates exemplified by Perkinsus sp., a "marine" protist responsible for mass-mortality events in commercial shellfish populations. Using small subunit (SSU) ribosomal DNA (rDNA) sequencing, we developed a targeted PCR protocol for preferentially sampling a clade of the Perkinsea. We tested this protocol on freshwater environmental DNA, revealing a wide diversity of Perkinsea lineages in these environments. Then, we used the same protocol to test for Perkinsea-like lineages in livers of 182 tadpoles from multiple families of frogs. We identified a distinct Perkinsea clade, encompassing a low level of SSU rDNA variation different from the lineage previously associated with tadpole mass-mortality events. Members of this clade were present in 38 tadpoles sampled from 14 distinct genera/phylogroups, from five countries across three continents. These data provide, to our knowledge, the first evidence that Perkinsea-like protists infect tadpoles across a wide taxonomic range of frogs in tropical and temperate environments, including oceanic islands.


Assuntos
Alveolados/patogenicidade , Anfíbios/classificação , Geografia , Larva/classificação , Alveolados/classificação , Anfíbios/crescimento & desenvolvimento , Animais , Larva/parasitologia , Filogenia , Especificidade da Espécie
18.
Acta Parasitol ; 60(2): 226-33, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26203989

RESUMO

Based on light and scanning electron microscopical studies, one known and one previously undescribed Procamallanus (Spirocamallanus) species (Nematoda: Camallanidae) are described from specimens collected in the intestine of freshwater fishes in the Lower Congo River, Democratic Republic of Congo: P. (S.) daleneae (Boomker 1993) from Synodontis acanthomias Boulenger (Mochokidae, Siluriformes) (new host and geographical records) and P. (S.) parachannae sp. nov. from Parachanna insignis (Sauvage) (Channidae, Perciformes). The new species is most similar to P. (S.) serranochromis Moravec et Van As 2015, a parasite of African cichlids (Serranochromis spp.), differing from it mainly in the absence of any outgrowths on the female tail tip, a distinctly longer (546 µm) right spicule, a different length ratio of both spicules (1:2.6) and in the morphology of fourth-stage larvae. P. (S.) daleneae, a specific parasite of squeakers (Synodontis spp.), is redescribed; in contrast to the original description, the number of postanal papillae was found to be identical (6 pairs) with that of other related species.


Assuntos
Doenças dos Peixes/parasitologia , Peixes/parasitologia , Infecções por Spirurida/veterinária , Espirurídios/classificação , Espirurídios/isolamento & purificação , Animais , República Democrática do Congo , Água Doce , Intestinos/parasitologia , Microscopia , Rios , Espirurídios/anatomia & histologia , Infecções por Spirurida/parasitologia
19.
Zootaxa ; 3893(2): 261-76, 2014 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-25544522

RESUMO

An examination of one specimen of Nile crocodile, Crocodylus niloticus (Laurenti, 1768), from Lake Turkana (Kenya), revealed the presence of two ascaridoid nematodes belonging to the genus Dujardinascaris Baylis, 1947. Dujardinascaris madagascariensis Chabaud & Caballero, 1966 was studied by scanning electron microscopy, redescribed, and differentiated from D. dujardini (Travassos, 1920). Dujardinascaris madagascariencsis is the second of the genus to be sequenced. An internal fragment of the small ribosomal subunit and nuclear ribosomal DNA internal transcribed spacer 2 region were amplified--the slowly evolving 18S gene region was used for phylogenetic analysis. Molecular data confirmed affinity of D. madagascariensis to the family Heterocheilidae and revealed its closest relationship with D. waltoni. A key to the species of Dujardinascaris parasitizing crocodiles is provided.


Assuntos
Jacarés e Crocodilos/parasitologia , Nematoides/classificação , Nematoides/genética , Infecções por Nematoides/veterinária , Distribuição Animal , Estruturas Animais/anatomia & histologia , Estruturas Animais/crescimento & desenvolvimento , Animais , Tamanho Corporal , DNA Espaçador Ribossômico/genética , Feminino , Quênia , Masculino , Nematoides/anatomia & histologia , Nematoides/crescimento & desenvolvimento , Infecções por Nematoides/parasitologia , Tamanho do Órgão , Filogenia
20.
Folia Parasitol (Praha) ; 61(4): 311-21, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25185402

RESUMO

Data on external ultrastructure of myxospores and internal ultrastructure of advanced pseudoplasmodia and myxospores of topotypic samples of Sphaerospora ranae (Morelle, 1929) from Rana dalmatina Bonaparte are provided, together with in situ hybridisation results. In both frogs examined, the infection was restricted to renal tubules and corpuscles. The infection site restriction was confirmed by light and transmission electron microscopy, as well as by in situ hybridisation. In addition, large myxospore masses measuring up to 500 microm were detected in seminal vesicles. Only late-sporogonic stages, i.e. pseudoplasmodia harbouring immature and/or mature myxospores, were observed and analysed. Scanning electron microscopy revealed that spores have smooth surface with exception of posterior valvular bulges, which possess numerous outwards opening internal canals. As revealed by both scanning and transmission electron microscopy, the canals are continuous invaginations of the outer spore surface. Myxospores of S. ranae are characterised by the presence of two uninucleate sporoplasms, bilayered polar capsules, S/H-shaped polar filaments in transversal section and multilayered polar filament eversion pole plugging complex. Ultrastructural observations are discussed in the context of available data for other species of Sphaerospora sensu stricto and apparent synchronisation of myxospore shedding with a brief aquatic breeding phase of vertebrate intermediate host is highlighted.


Assuntos
Rim/parasitologia , Myxozoa/crescimento & desenvolvimento , Myxozoa/ultraestrutura , Doenças Parasitárias em Animais/parasitologia , Ranidae/parasitologia , Animais , Especificidade da Espécie
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