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1.
BMC Evol Biol ; 20(1): 156, 2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228518

RESUMO

BACKGROUND: Ecdysozoa are the moulting protostomes, including arthropods, tardigrades, and nematodes. Both the molecular and fossil records indicate that Ecdysozoa is an ancient group originating in the terminal Proterozoic, and exceptional fossil biotas show their dominance and diversity at the beginning of the Phanerozoic. However, the nature of the ecdysozoan common ancestor has been difficult to ascertain due to the extreme morphological diversity of extant Ecdysozoa, and the lack of early diverging taxa in ancient fossil biotas. RESULTS: Here we re-describe Acosmia maotiania from the early Cambrian Chengjiang Biota of Yunnan Province, China and assign it to stem group Ecdysozoa. Acosmia features a two-part body, with an anterior proboscis bearing a terminal mouth and muscular pharynx, and a posterior annulated trunk with a through gut. Morphological phylogenetic analyses of the protostomes using parsimony, maximum likelihood and Bayesian inference, with coding informed by published experimental decay studies, each placed Acosmia as sister taxon to Cycloneuralia + Panarthropoda-i.e. stem group Ecdysozoa. Ancestral state probabilities were calculated for key ecdysozoan nodes, in order to test characters inferred from fossils to be ancestral for Ecdysozoa. Results support an ancestor of crown group ecdysozoans sharing an annulated vermiform body with a terminal mouth like Acosmia, but also possessing the pharyngeal armature and circumoral structures characteristic of Cambrian cycloneuralians and lobopodians. CONCLUSIONS: Acosmia is the first taxon placed in the ecdysozoan stem group and provides a constraint to test hypotheses on the early evolution of Ecdysozoa. Our study suggests acquisition of pharyngeal armature, and therefore a change in feeding strategy (e.g. predation), may have characterised the origin and radiation of crown group ecdysozoans from Acosmia-like ancestors.


Assuntos
Fósseis , Invertebrados , Filogenia , Animais , Artrópodes/anatomia & histologia , Artrópodes/classificação , Teorema de Bayes , China , Invertebrados/anatomia & histologia , Invertebrados/classificação , Nematoides/anatomia & histologia , Nematoides/classificação , Tardígrados/anatomia & histologia , Tardígrados/classificação
2.
PLoS One ; 15(10): e0240336, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33027282

RESUMO

Nematodes are representative soil metazoans with diverged species that play crucial roles in nutrient recycling in the pedosphere. Qualitative and quantitative information on nematode communities is useful for assessing soil quality, and DNA barcode-mediated taxonomic analysis is a powerful tool to investigate taxonomic compositions and changes in nematode communities. Here, we investigated four regions (regions 1-4) of the 18S small subunit ribosomal RNA (SSU) gene as PCR targets of deep amplicon sequencing for the taxonomic profiling of individual soil nematodes. We determined the sequence variants (SVs) of 4 SSU regions for 96 nematodes (total 384 amplicons) isolated from copse soils and assigned their taxonomy using the QIIME2 software with dada2 or deblur algorithm and the SILVA database. Dada2 detected approximately 2-fold more nematode-derived SVs than deblur, and a larger number of SVs were obtained in regions 1 and 4 than those in other regions. These results and sufficient reference sequence coverage in region 4 indicated that DNA barcoding using a primer set for region 4 followed by dada2-based analysis would be most suitable for soil nematode taxonomic analysis. Eighteen SSU-derived operational taxonomic units (rOTUs) were obtained from 68 isolates, and their orders were determined based on the phylogenetic trees built by four regional sequences of rOTUs and 116 nematode reference species as well as the BLASTN search. The majority of the isolates were derived from three major orders Dorylaimida (6 rOTUs, 51.5% in 68 isolates), Rhabditida (4 rOTUs, 29.4%), and Triplonchida (7 rOTUs, 17.6%). The predicted feeding types of the isolates were fungivores (38.2% in total nematodes), plant feeders (32.4%), and 14.7% for both bacterivores and omnivores/predators. Additionally, we attempted to improve the branch structure of phylogenetic trees by using long nucleotide sequences artificially prepared by connecting regional sequences, but the effect was limited.


Assuntos
Código de Barras de DNA Taxonômico/métodos , Nematoides/classificação , RNA Ribossômico 18S/genética , Solo/parasitologia , Animais , DNA de Protozoário/genética , DNA Ribossômico/genética , Nematoides/genética , Filogenia , Análise de Sequência de DNA , Software
3.
Nat Commun ; 11(1): 3870, 2020 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-32747621

RESUMO

Soils harbor a substantial fraction of the world's biodiversity, contributing to many crucial ecosystem functions. It is thus essential to identify general macroecological patterns related to the distribution and functioning of soil organisms to support their conservation and consideration by governance. These macroecological analyses need to represent the diversity of environmental conditions that can be found worldwide. Here we identify and characterize existing environmental gaps in soil taxa and ecosystem functioning data across soil macroecological studies and 17,186 sampling sites across the globe. These data gaps include important spatial, environmental, taxonomic, and functional gaps, and an almost complete absence of temporally explicit data. We also identify the limitations of soil macroecological studies to explore general patterns in soil biodiversity-ecosystem functioning relationships, with only 0.3% of all sampling sites having both information about biodiversity and function, although with different taxonomic groups and functions at each site. Based on this information, we provide clear priorities to support and expand soil macroecological research.


Assuntos
Biodiversidade , Ecossistema , Microbiologia do Solo , Solo/parasitologia , Animais , Bactérias/classificação , Bactérias/metabolismo , Biomassa , Clima , Fungos/classificação , Fungos/metabolismo , Geografia , Concentração de Íons de Hidrogênio , Nematoides/classificação , Nematoides/metabolismo , Oligoquetos/classificação , Oligoquetos/metabolismo , Solo/química , Temperatura
4.
J Parasitol ; 106(4): 439-443, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615595

RESUMO

Age-related dynamics of protozoan and helminth infections in the red-legged partridge, Alectoris rufa, were studied in an intensive breeding aviary in the Czech Republic before releasing birds for hunting purposes. Pooled fecal samples (n = 900) were examined over 3 rearing seasons (2012-2014). A total of 4 protozoan species, Cryptosporidium baileyi, Cryptosporidium meleagridis, Eimeria kofoidi, and Eimeria legionensis, and 4 helminths, Capillaria phasianina, Eucoleus perforans, Heterakis gallinarum, and Syngamus trachea, was found. The most common parasite was S. trachea (prevalence 20-26%) in dead birds (n = 99), which represents a high risk for breeders. Co-occurrence of protozoans and helminths indicated similarities in infection dynamics throughout the 3 breeding seasons. Mixed infections of Cryptosporidium baileyi and C. meleagridis with other parasitic species are reported for the first time. Our findings provide new insights into breeding of A. rufa and may help to improve the efficacy of disease control strategies and prevention, especially with the potential for spreading of parasitic infections to wildlife through released birds into open areas.


Assuntos
Doenças das Aves/parasitologia , Galliformes/parasitologia , Helmintíase Animal/epidemiologia , Infecções Protozoárias em Animais/epidemiologia , Fatores Etários , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/transmissão , Capillaria/classificação , Capillaria/isolamento & purificação , Cryptosporidium/classificação , Cryptosporidium/isolamento & purificação , República Tcheca/epidemiologia , Eimeria/classificação , Eimeria/isolamento & purificação , Fezes/parasitologia , Helmintíase Animal/parasitologia , Helmintíase Animal/transmissão , Helmintos/classificação , Helmintos/isolamento & purificação , Nematoides/classificação , Nematoides/isolamento & purificação , Prevalência , Infecções Protozoárias em Animais/parasitologia , Infecções Protozoárias em Animais/transmissão , Fatores de Risco , Espirurídios/classificação , Espirurídios/isolamento & purificação , Strongyloidea/classificação , Strongyloidea/isolamento & purificação
5.
Rev Bras Parasitol Vet ; 29(2): e001420, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32520087

RESUMO

Buteogallus schistaceus (Sundevall) is an endemic bird of prey from the Amazon region, with a declining population according to international conservation agencies. The objective of this study was to report the occurrence of a parasitic nematodes in an individual treated at the Ambulatório de Animais Silvestres of Universidade Federal Rural da Amazônia, Belém campus. The animal was captured on campus and showed no resistance to capture. Fluid therapy and deworming were made, later the bird regurgited ten nematodes identified as belonging to the genus Procyrnea Chabaud (1958). Reviewing the scientific literature, it was found that so far there are no records on the helminth fauna of this bird species, which is therefore the first report of a nematode in B. schistaceus.


Assuntos
Doenças das Aves/parasitologia , Aves/parasitologia , Nematoides/anatomia & histologia , Nematoides/classificação , Animais , Feminino , Masculino , Nematoides/isolamento & purificação
6.
Syst Parasitol ; 97(4): 389-401, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32533535

RESUMO

Within the cetacean lungworm family Pseudaliidae Raillet & Henry, 1909, the distinction between the two genera of the subfamily Halocercinae Delamure, 1952, i.e. Halocercus Baylis & Daubney, 1925 and Skrjabinalius Delyamure, 1942, is principally based on the structure and shape of the male copulatory bursa. In species of Halocercus, the bursa is unlobed, whereas in the two species included in Skrjabinalius, S. cryptocephalus Delyamure, 1942 and Skrjabinalius guevarai Gallego & Selva, 1979, the bursa is described as clearly lobed. During a parasitological analysis of cetaceans from the Spanish Mediterranean, we collected a number of specimens of S. guevarai with variable levels of bursal lobulation, including individuals with unlobed bursae. Examination of voucher specimens of the type-species of Halocercus, H. delphini Baylis & Daubney, 1925, collected from cetaceans in the North-East Atlantic revealed the same variations in bursal shape, and the same arrangement of bursal rays and papillae. A morphometric comparison did not reveal substantial differences between both species. Moreover, Maximum Likelihood and Bayesian Inference analyses of the second internal transcribed spacer (ITS2) sequences of 11 specimens of S. guevarai and one of H. delphini grouped both species together, regardless of bursal shape, in a highly supported clade within the Pseudaliidae. Accordingly, we consider S. guevarai as a junior synonym of H. delphini. The great variability found in bursal lobulation in the type-species of Halocercus invalidates the use of this trait as a genus-level diagnostic character and, therefore, Skrjabinalius should also be considered synonymous with Halocercus.


Assuntos
Nematoides/classificação , Filogenia , Animais , Cetáceos/parasitologia , DNA Espaçador Ribossômico/genética , Masculino , Nematoides/anatomia & histologia , Nematoides/genética , Especificidade da Espécie
7.
Syst Parasitol ; 97(4): 369-378, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32562125

RESUMO

Rhabdias delangei n. sp. (Nematoda: Rhabdiasidae) is described from the lungs of the clicking stream frog Strongylopus grayii (Smith) in the Western Cape Province of South Africa. The new species is characterised by the nerve-ring being located just posterior to the mid-length of the oesophagus, a pre-equatorial vulva, as well as a thin-walled and apparently underdeveloped rectum. Pairwise analyses based on ITS-28S and partial cox1 gene fragments showed significant differences between R. delangei n. sp. and its congeners from the Afrotropical Realm. Rhabdias delangei n. sp. is the 12th species of Rhabdias Stiles & Hassall, 1905 recorded in Afrotropical amphibians and the second species of the genus found in pyxicephalid hosts. Our phylogenetic analysis based on the ITS-28S region showed that the new species is closely related to the European species R. rubrovenosa (Schneider, 1866). Furthermore, both species are similar with respect to the underdeveloped rectum and pre-equatorial position of vulva.


Assuntos
Anuros/parasitologia , Nematoides/classificação , Animais , DNA de Helmintos/genética , Pulmão/parasitologia , Nematoides/anatomia & histologia , Nematoides/genética , Filogenia , África do Sul , Especificidade da Espécie
8.
Syst Parasitol ; 97(4): 403-408, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32562126

RESUMO

Leidynemella shahi n. sp. is described based on material from Panesthia angustipennis cognata Bey-Bienko and Salganea raggei Roth in the Yunnan Province, China. The new species is very similar to L. fusiformis Cobb in Chitwood & Chitwood, 1934, but differs from the latter in the position of the nerve-ring and vulva, and in the length of the eggs. In addition, molecular analysis of partial 28S rDNA sequences also supported the distinct status of the new species.


Assuntos
Baratas/parasitologia , Nematoides/classificação , Animais , China , Nematoides/anatomia & histologia , Nematoides/genética , RNA Ribossômico 28S/genética , Especificidade da Espécie
9.
Parasite ; 27: 37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32425154

RESUMO

Recent examinations of cucullanid nematodes (Cucullanidae) from marine fishes off New Caledonia, collected in the years 2004-2009, revealed the presence of the following five new species of Cucullanus Müller, 1777, all parasitic in Perciformes: Cucullanus variolae n. sp. from Variola louti (type host) and V. albimarginata (both Serranidae); Cucullanus acutospiculatus n. sp. from Caesio cuning (Caesionidae); Cucullanus diagrammae n. sp. from Diagramma pictum (Haemulidae); Cucullanus parapercidis n. sp. from Parapercis xanthozona (type host) and P. hexophtalma (both Pinguipedidae); and Cucullanus petterae n. sp. from Epinephelus merra (type host) and E. fasciatus (both Serranidae). An additional congeneric species, Cucullanus bioccai Orecchia et Paggi, 1987 was recorded from Mugil cephalus (Mugilidae, Mugiliformes) (first record in the Pacific Ocean) and Cucullanus sp. (only female) was found in Arothron manilensis (Tetraodontidae, Tetraodontiformes). Furthermore, two known cucullanid species, Dichelyne (Cucullanellus) branchiostegi (Yamaguti, 1941) in Branchiostegus wardi (Malacanthidae, Perciformes) (new host and geographical records) and Dichelyne (Cucullanellus) bodiani Moravec et Justine, 2019 in Bodianus busellatus (new host) and B. perditio (both Labridae, Perciformes), were found; Dichelyne (Cucullanellus) sp. (only females) coinfecting the latter host may represent an unknown species. Most species are described based on light and electron microscopical studies. The specimens described by Xu et al., 2017 as Cucullanus bourdini Petter et Le Bel, 1992 from Caesio xanthonota (Caesionidae) in the Taiwan Strait are considered to represent a new species, for which the name Cucullanus sinensis n. sp. is proposed.


Assuntos
Nematoides/anatomia & histologia , Nematoides/classificação , Perciformes/parasitologia , Animais , Feminino , Masculino , Microscopia , Microscopia Eletrônica , Nematoides/isolamento & purificação , Nematoides/ultraestrutura , Nova Caledônia , Oceano Pacífico
10.
Nat Commun ; 11(1): 1964, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32327641

RESUMO

Sex determination mechanisms often differ even between related species yet the evolution of sex chromosomes remains poorly understood in all but a few model organisms. Some nematodes such as Caenorhabditis elegans have an XO sex determination system while others, such as the filarial parasite Brugia malayi, have an XY mechanism. We present a complete B. malayi genome assembly and define Nigon elements shared with C. elegans, which we then map to the genomes of other filarial species and more distantly related nematodes. We find a remarkable plasticity in sex chromosome evolution with several distinct cases of neo-X and neo-Y formation, X-added regions, and conversion of autosomes to sex chromosomes from which we propose a model of chromosome evolution across different nematode clades. The phylum Nematoda offers a new and innovative system for gaining a deeper understanding of sex chromosome evolution.


Assuntos
Evolução Molecular , Nematoides/genética , Infecções por Nematoides/parasitologia , Cromossomos Sexuais/genética , Animais , Brugia Malayi/genética , Caenorhabditis elegans/genética , Mapeamento Cromossômico , Feminino , Regulação da Expressão Gênica , Genoma Helmíntico/genética , Humanos , Masculino , Nematoides/classificação , Sequências Repetitivas de Ácido Nucleico/genética , Processos de Determinação Sexual/genética
11.
Parasitol Int ; 77: 102105, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32179135

RESUMO

Anthelmintic resistance (AR) against gastrointestinal nematodes (GINs) of sheep and goats is a global concern. To address the problem, this study assessed the status of AR in different government and private sheep and goat farms in Bangladesh. We conducted fecal egg count reduction test (FECRT) and Egg hatch assay (EHA) experiments. For the detection of resistant larvae, pooled fecal samples from treated and non-treated groups were subjected to coproculture. Furthermore, 195 adult Haemonchus parasites were genotyped to ascertain benzimidazole (BZ) resistance allele from seven topographic zones of Bangladesh using allele specific PCR (AS-PCR). In FECRT, the percentage reduction along with 95% confidence intervals indicated that GINs were resistant to albendazole (ABZ), levamisole (LEV) and ivermectin (IVM). Coproculture revealed that Haemonchus spp., Oesophagostomum spp. and Trichostrongylus spp. were resistant to anthelmintics. ABZ resistance was also confirmed by in vitro EHA in all the farms except the private goat farm in Mymensingh. The genotype frequencies were 6% for homozygous resistant (rr), 59% for heterozygous (rS) and 35% for homozygous susceptible (SS) among different topographic zones. The allelic frequency of the mutation conferring resistance (r) ranged from 25% to 47% signifying resistance to BZ in nematodes of sheep/goats. The genotype frequencies (rr, rS and SS) and allelic frequencies (r and S) varied significantly (p˂0.05) in different zones in Bangladesh. Overall, the data suggest an alarming condition created by multiple AR in Bangladesh.


Assuntos
Anti-Helmínticos/uso terapêutico , Resistência a Medicamentos/genética , Trato Gastrointestinal/parasitologia , Nematoides/efeitos dos fármacos , Ruminantes/parasitologia , Alelos , Animais , Bangladesh , Fazendas , Fezes/parasitologia , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/parasitologia , Cabras/parasitologia , Haemonchus/efeitos dos fármacos , Haemonchus/genética , Nematoides/classificação , Oesophagostomum/efeitos dos fármacos , Oesophagostomum/genética , Contagem de Ovos de Parasitas , Ovinos/parasitologia , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Trichostrongylus/efeitos dos fármacos , Trichostrongylus/genética
12.
Ann Parasitol ; 66(1): 27­37, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32198993

RESUMO

Hoplias aff. malabaricus is abundant in the Mogi-Guaçu River. The aim of this study was to perform an inventory of the species of metazoan that parasite this species of fish taken from oxbow lakes of the Mogi-Guaçu River. The Mann-Whitney test was used to statistically analyze the possible influence of the sex of the host on the group with the highest parasite richness and the greatest abundance of parasites. Simpson's diversity index was used to determine parasite diversity among the zoological groups of parasites of H. aff. malabaricus with the highest index. A total of 78 specimens of H. aff. malabaricus were examined. Among the zoological groups of metazoans found, the phylum Nematoda had the greatest number of species. Among these, the larval stage of Contracaecum sp. was most abundant. The sex of the host had a significant effect, with parasites more abundant in female fish (Z(U)=0.043; p<0.05). The digenean Parspina argentinensis, the nematodes Procamallanus (S.) iheringi, Rhabdochona acuminata and Hysterothylacium sp. and copepods Vaigamus sp. and Lernaea cyprinacea have not previously been recorded as parasites of H. aff. malabaricus.


Assuntos
Doenças dos Peixes , Parasitos , Doenças Parasitárias em Animais , Animais , Biodiversidade , Brasil/epidemiologia , Caraciformes/parasitologia , Copépodes/classificação , Feminino , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia , Helmintos/classificação , Helmintos/isolamento & purificação , Masculino , Nematoides/classificação , Nematoides/isolamento & purificação , Doenças Parasitárias em Animais/epidemiologia , Doenças Parasitárias em Animais/parasitologia , Prevalência , Rios , Fatores Sexuais
13.
Ann Parasitol ; 66(1): 39­47, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32198994

RESUMO

The present study describes the helminth community collected from juveniles of Dermatonotus muelleri (Anura: Microhylidae) from the Chaco Seco Ecoregion. Helminths were found in 80.0% of specimens examined (n = 16). The helminth community of this microhylid presented very low species richness; a total of 1,339 specimens belonging four helminth species were found; three adult nematodes, Aplectana hylambatis, Cosmocerca podicipinus and Parapharyngodon sp., and an adult cestode, Ophiotaenia sp. Parasites were found in the large and small intestines. Maximum helminth richness was 2 species per infected frog. The nematode A. hylambatis presented the highest prevalence and was the most abundant (d = 0.97) indicating that it is the dominant species in the community (I = 63.0). Host snout-vent length did not influence the intensity of infection or the richness of helminth species at the community component level. Two species showed significant co-variation (A. hylambatis and Parapharyngodon sp.). The high prevalence of infection and number of parasites found for A. hylambatis could be related to the characteristics of their life cycles; the possession of the infective stage (L3) protected inside the egg membrane would have benefits against extreme drought in the area in which the study was conducted. The studies of helminths in the Chaco Seco Ecoregion, an area seriously threatened in terms of its biodiversity, are incipient. This is the second study that has been carried out to determine the structure of the parasite community in amphibians of this ecoregion.


Assuntos
Anuros , Biodiversidade , Helmintíase Animal , Helmintos , Nematoides , Animais , Anuros/parasitologia , Clima Desértico , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Helmintos/classificação , Nematoides/classificação , Prevalência , Estados Unidos
14.
PLoS One ; 15(3): e0230153, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32182269

RESUMO

Soil biodiversity plays a key regulation role in the ecosystem services that underpin regenerative sustainable agriculture. It can be impacted by agricultural management techniques, both positively (through measures such as compost application) and negatively (through, for example, application of synthetic nitrogen). As one of the most numerous members of the soil biota, nematodes are well established as indicators for the soil food web. However, compost application also includes the addition of nematodes present in compost and their subsequent survival in soil is unknown. Nematode communities within the compost applied to soil, and nematode communities in the soil of a multi-year rotational cropping field trial in Melle (Belgium) were studied using morphological and metabarcoding techniques. Compost (C) and nitrogen fertilizer (NF) treated plots were compared. Three replicate plots were investigated for each of the following treatments: C application only; C and NF application; NF only; no C and no NF (control). Plots were sampled six times between 2015-2017, before and after C or NF were added each spring and after crop harvest (except for 2017). NF treatment resulted in a significant decrease of fungal feeding and predatory nematodes, while herbivorous nematodes were positively affected. Remarkably, we did not find compost addition to exert any noticeable effects on the soil nematode community. The morphological and metabarcoding data resulted in different results of the nematode community composition. However, trends and patterns in the two data sets were congruent when observed with NMDS plots and using the nematode maturity index. Metabarcoding of individual compost nematode taxa demonstrated that nematodes originating from compost did not persist in soil.


Assuntos
Compostagem , Fertilizantes , Nematoides , Microbiologia do Solo , Animais , Produção Agrícola/métodos , Ecossistema , Cadeia Alimentar , Metagenômica , Nematoides/anatomia & histologia , Nematoides/classificação , Nematoides/genética , Nematoides/crescimento & desenvolvimento , Compostos de Nitrogênio , Solo/química
15.
Parasit Vectors ; 13(1): 135, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32171333

RESUMO

BACKGROUND: Australian marsupials harbour a diverse array of helminth parasites. Despite current attempts to assess the extent of this diversity in macropodid hosts, it has been suggested that unique parasite fauna of Australian wildlife is difficult to document comprehensively due to the common occurrence of cryptic species. This paper assessed genetic variation within Austrostrongylus thylogale Johnston & Mawson, 1940 from the tammar wallaby, Notamacropus eugenii (Gray), and the quokka, Setonix brachyurus (Quoy & Gaimard), from different localities using the molecular characterisation of the internal transcribed spacers (ITS) within the nuclear ribosomal DNA. METHODS: Thirty-seven specimens of A. thylogale collected from N. eugenii (from Parndana, Kangaroo Island, South Australia, and Perup, Western Australia) and S. brachyurus (from Wellington Dam, Western Australia) were characterised using a molecular-phylogenetic approach utilising the first (ITS1) and second (ITS2) internal transcribed spacers. RESULTS: Genetic variation was detected in both ITS1 and ITS2 between specimens of A. thylogale from N. eugenii and S. brachyurus; however, no variation was detected between specimens collected from N. eugenii from Parndana, South Australia, and Perup, Western Australia. Furthermore, the phylogenetic analyses of ITS sequences showed two clades of A. thylogale originating from two hosts, N. eugenii and S. brachyurus, suggesting the presence of cryptic species. CONCLUSIONS: This study provides evidence of genetic variation within A. thylogale based on collections from two different host species. Morphological studies are required to fully confirm the presence of a new species or cryptic species. Further molecular studies using a larger number of specimens are warranted to explore the genetic variation between A. thylogale from different geographical localities.


Assuntos
Variação Genética , Macropodidae/parasitologia , Nematoides/classificação , Nematoides/genética , Animais , Austrália , DNA de Helmintos/genética , DNA Ribossômico/genética , Especificidade de Hospedeiro , Macropodidae/classificação , Filogenia , Alinhamento de Sequência , Trichostrongyloidea
16.
Sci Data ; 7(1): 103, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32218461

RESUMO

As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns.


Assuntos
Distribuição Animal , Nematoides/classificação , Animais , Ecossistema , Solo
17.
Parasit Vectors ; 13(1): 70, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32113470

RESUMO

BACKGROUND: Gastrointestinal nematodes are parasites that commonly infect dogs, and infections can be subclinical or may cause considerable clinical disease. Some species are zoonotic and may also cause clinical disease in humans. Year-round treatment of dogs is recommended to eliminate existing infections, which also indirectly reduces the potential for subsequent human exposure to zoonotic species. Here we present two studies that evaluated the safety and efficacy of a novel chewable oral tablet containing sarolaner, moxidectin and pyrantel against gastrointestinal nematode infections in dogs presented as veterinary patients in Europe and the USA. METHODS: Dogs naturally infected with Toxocara canis, Toxascaris leonina, Ancylostoma caninum and/or Uncinaria stenocephala were enrolled in the European study, and dogs naturally infected with T. canis were enrolled in the USA study. The animals were treated once orally with Simparica Trio™ tablets to provide 1.2-2.4 mg/kg sarolaner, 24-48 µg/kg moxidectin and 5-10 mg/kg pyrantel (as pamoate salt) or with a commercially available product according to the label directions as positive control. Efficacy was based on the post-treatment reduction in geometric mean egg counts (per gram feces) 7 or 10 days after treatment compared to pre-treatment egg counts. RESULTS: Simparica Trio™ was well tolerated in both studies. In the European study, geometric mean egg counts for T. canis, T. leonina, A. caninum and U. stenocephala were reduced by ≥ 98.3% in the Simparica Trio™ group and by ≥ 97.4% in the afoxolaner + milbemycin oxime group. In the USA study, geometric mean egg counts for T. canis were reduced by 99.2% in the Simparica Trio™ group and by 98.6% in the ivermectin + pyrantel group. In the USA study, 48 and 10 dogs in the Simparica Trio™ and the ivermectin + pyrantel group, respectively, were co-infected with A. caninum and the reduction in the post-treatment mean fecal egg counts were 98.6% and 74.7%, respectively. CONCLUSIONS: A single oral administration of Simparica Trio™ chewable tablets was well tolerated and was effective in the treatment of dogs with naturally occurring gastrointestinal nematode infections presented as veterinary patients in Europe and the USA.


Assuntos
Antinematódeos/administração & dosagem , Doenças do Cão/tratamento farmacológico , Enteropatias Parasitárias/veterinária , Nematoides/efeitos dos fármacos , Infecções por Nematoides/veterinária , Administração Oral , Animais , Azetidinas/administração & dosagem , Cães , Combinação de Medicamentos , Europa (Continente) , Feminino , Enteropatias Parasitárias/tratamento farmacológico , Macrolídeos/administração & dosagem , Masculino , Nematoides/classificação , Infecções por Nematoides/tratamento farmacológico , Contagem de Ovos de Parasitas , Pirantel/administração & dosagem , Compostos de Espiro/administração & dosagem , Resultado do Tratamento , Estados Unidos
18.
Rev Bras Parasitol Vet ; 29(1): e013119, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049139

RESUMO

The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.


Assuntos
Anti-Helmínticos/administração & dosagem , Trato Gastrointestinal/parasitologia , Monoterpenos/administração & dosagem , Nanocápsulas/administração & dosagem , Nematoides/efeitos dos fármacos , Infecções por Nematoides/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Animais , Anti-Helmínticos/toxicidade , Fezes/parasitologia , Feminino , Camundongos , Monoterpenos/toxicidade , Nanocápsulas/toxicidade , Nematoides/classificação , Nematoides/isolamento & purificação , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas , Testes de Sensibilidade Parasitária , Reação em Cadeia da Polimerase em Tempo Real , Roedores , Ovinos , Doenças dos Ovinos/parasitologia , Testes de Toxicidade
19.
Syst Parasitol ; 97(2): 157-163, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32065371

RESUMO

Based on light and scanning electron microscopical studies, a new nematode parasite, Paracapillaria (Paracapillaria) gastrica n. sp. (Capillariidae), is described from the stomach of the marine fish (variegated lizardfish) Synodus variegatus (Lacépède) (Aulopiformes: Synodontidae) from off New Caledonia. This species is mainly characterised by the length of the spicule (267 µm), the proximal spicule end expanded to form a conspicuous folded, lobular rim, the presence of a well-developed caudal bursa supported by two lateral projections (rays) not adhering to the posterior border of body and by the size of eggs (54-60 × 24-27 µm) with non-protruding polar plugs. Paracapillaria gastrica n. sp. is the first known capillariid species parasitic in a host belonging to the fish order Aulopiformes and the first species of this genus reported from fishes in New Caledonian waters and the South Pacific Ocean.


Assuntos
Peixes/parasitologia , Nematoides/classificação , Animais , Nematoides/anatomia & histologia , Nova Caledônia , Oceano Pacífico , Especificidade da Espécie
20.
Parasite ; 27: 6, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32003324

RESUMO

Parasite communities in Caranx sexfasciatus were characterized and analyzed to determine any interannual variations in structure and/or species composition. In total, 422 C. sexfasciatus were collected from Acapulco Bay, Mexico, between May 2016 and March 2019. Thirty-two taxa of metazoan parasites were identified: five Monogenea, thirteen Digenea, one Acanthocephala, one Cestoda, three Nematoda, seven Copepoda, and two Isopoda. Monogeneans were the most frequent and abundant parasite species in all sampling years. Parasite species richness at the component community level varied significantly from 8 (May 2016) to 25 (March 2019) and was similar to previous reports for other species of Carangidae. The component communities and infracommunities in C. sexfasciatus were characterized by low parasite species numbers, low diversity, and dominance of a single species (the monogenean Neomicrocotyle pacifica). Parasite community structure and species composition varied between sampling years and climatic seasons. Seasonal or local fluctuations in some biotic and abiotic environmental factors probably explain these variations.


Assuntos
Doenças dos Peixes/parasitologia , Parasitos/classificação , Perciformes/parasitologia , Acantocéfalos/classificação , Acantocéfalos/isolamento & purificação , Animais , Cestoides/classificação , Cestoides/isolamento & purificação , Clima , Copépodes , Ecossistema , México , Nematoides/classificação , Nematoides/isolamento & purificação , Estações do Ano , Trematódeos/classificação , Trematódeos/isolamento & purificação
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