Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.515
Filtrar
1.
PLoS Negl Trop Dis ; 14(8): e0008627, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866158

RESUMO

The application of reverse genetics in the human filarial parasites has lagged due to the difficult biology of these organisms. Recently, we developed a co-culture system that permitted the infective larval stage of Brugia malayi to be transfected and efficiently develop to fecund adults. This was exploited to develop a piggyBac transposon-based toolkit that can be used to produce parasites with transgene sequences stably integrated into the parasite genome. However, the piggyBac system has generally been supplanted by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) based technology, which allows precise editing of a genome. Here we report adapting the piggyBac mediated transfection system of B. malayi for CRISPR mediated knock-in insertion into the parasite genome. Suitable CRISPR insertion sites were identified in intergenic regions of the B. malayi genome. A dual reporter piggybac vector was modified, replacing the piggyBac inverted terminal repeat regions with sequences flanking the insertion site. B. malayi molting L3 were transfected with a synthetic guide RNA, the modified plasmid and the CAS9 nuclease. The transfected parasites were implanted into gerbils and allowed to develop into adults. Progeny microfilariae were recovered and screened for expression of a secreted luciferase reporter encoded in the plasmid. Approximately 3% of the microfilariae were found to secrete luciferase; all contained the transgenic sequences inserted at the expected location in the parasite genome. Using an adaptor mediated PCR assay, transgenic microfilariae were examined for the presence of off target insertions; no off-target insertions were found. These data demonstrate that CRISPR can be used to modify the genome of B. malayi, opening the way to precisely edit the genome of this important human filarial parasite.


Assuntos
Brugia Malayi/genética , Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Transfecção/métodos , Animais , Animais Geneticamente Modificados , Sequência de Bases , DNA de Helmintos/genética , Feminino , Edição de Genes , Genoma , Larva/genética , Luciferases , Microfilárias/genética
2.
Korean J Parasitol ; 58(4): 373-386, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32871631

RESUMO

Fish-borne heterophyid trematodes are known to have a zoonotic potential, since at least 30 species are able to infect humans worldwide, with a global infection of around 7 million people. In this paper, a 'state-of-the-art' review of the South American heterophyid species is provided, including classical and molecular taxonomy, parasite ecology, host-parasite interaction studies and a list of species and their hosts. There is still a lack of information on human infections in South America with undetected or unreported infections probably due to the information shortage and little attention by physicians to these small intestinal flukes. Molecular tools for specific diagnoses of South American heterophyid species are still to be defined. Additional new sequences of Pygidiopsis macrostomum, Ascocotyle pindoramensis and Ascocotyle longa from Brazil are also provided.


Assuntos
Heterophyidae , Animais , Cianobactérias , DNA de Helmintos/genética , Peixes/parasitologia , Heterophyidae/classificação , Heterophyidae/genética , Heterophyidae/patogenicidade , Interações Hospedeiro-Parasita , Humanos , Análise de Sequência de DNA , América do Sul , Infecções por Trematódeos/parasitologia
3.
Korean J Parasitol ; 58(4): 451-456, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32871639

RESUMO

This is a report of 2 cases of human hydatidosis caused by Echinococcus ortleppi in Vietnam. The patients were a 12-year-old male (case 1) having a cyst of 10.0×9.0 cm size in the lung and a 50-year-old female with a 3.0×3.3 cm-sized cyst in the heart. Eosinophilia was 33.7% in the male and 45.8% in the female patient. C-reactive protein was increased to 16.5 mg/L in the male and 18.2 mg/L in the female. Both patients were positive for ELISA at OD=2.5 and 3.1, respectively. Echinococcus protoscolices were collected from the cysts by amniocentesis and surgery. The protoscolices were identified as E. ortleppi by morphology and analysis of mitochondrial NADH dehydrogenase 1 (nad1) gene sequence. Both patients were cured by surgical resection of the hydatid cyst combined with albendazole medication. The E. ortleppi infection in lung is the second report, and the other in the heart is the first in Vietnam.


Assuntos
Equinococose/diagnóstico , Equinococose/parasitologia , Albendazol/uso terapêutico , Animais , Biomarcadores , Proteína C-Reativa , Criança , DNA de Helmintos/genética , DNA Mitocondrial/genética , Equinococose/cirurgia , Echinococcus/genética , Echinococcus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Feminino , Cardiopatias , Humanos , Pneumopatias Parasitárias , Masculino , Pessoa de Meia-Idade , NADH Desidrogenase/genética , Análise de Sequência de DNA , Vietnã
4.
Syst Parasitol ; 97(5): 409-439, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32813221

RESUMO

The Proterodiplostomidae Dubois, 1936 is a relatively small family of diplostomoidean digeneans parasitising the intestines of reptilian hosts associated with freshwater environments in tropical and subtropical regions. The greatest diversity of proterodiplostomids is found in crocodilians, although some parasitise snakes and turtles. According to the most recent revision, the Proterodiplostomidae included 17 genera within 5 subfamilies. Despite the complex taxonomic structure of the family, availability of testable morphology-based phylogenetic hypotheses and ancient hosts, molecular phylogenetic analyses of the group were practically lacking. Herein, we use novel DNA sequence data of the nuclear lsrRNA gene and mitochondrial cox1 gene from a broad range of proterodiplostomid taxa obtained from crocodilian, fish, and snake hosts on four continents to test the monophyly of the family and evaluate the present morphology-based classification system of the Proterodiplostomidae in comparison with the molecular phylogeny. This first detailed phylogeny for the Proterodiplostomidae challenges the current systematic framework. Combination of molecular phylogenetic data with examination of freshly collected quality specimens and re-evaluation of morphological criteria resulted in a number of systematic and nomenclatural changes along with a new phylogeny-based classification of the Proterodiplostomidae. As the result of our molecular and morphological analyses: (i) the current subfamily structure of the Proterodiplostomidae is abolished; (ii) three new genera, Paraproterodiplostomum n. g., Neocrocodilicola n. g. and Proteroduboisia n. g., are described and Pseudoneodiplostomoides Yamaguti, 1954 is restored and elevated from subgenus to genus level; (iii) two new species, Paraproterodiplostomum currani n. g., n. sp. and Archaeodiplostomum overstreeti n. sp., are described from the American alligator in Mississippi, USA. Comparison of the structure of terminal ducts of the reproductive system in all proterodiplostomid genera did not support the use of these structures for differentiation among subfamilies (or major clades) within the family, although they proved to be useful for distinguishing among genera and species. Our study includes the first report of proterodiplostomids from Australia and the first evidence of a snake acting as a paratenic host for a proterodiplostomid. A key to proterodiplostomid genera is provided. Questions of proterodiplostomid-host associations parasitic in crocodilians are discussed in connection with their historical biogeography. Our molecular phylogeny of the Proterodiplostomidae closely matches the current molecular phylogeny of crocodilians. Directions for future studies of the Proterodiplostomidae are outlined.


Assuntos
Filogenia , Répteis/parasitologia , Trematódeos/classificação , Animais , DNA de Helmintos/genética , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/genética
5.
Syst Parasitol ; 97(5): 517-528, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32776273

RESUMO

Centrorhynchus Lühe, 1911 is a large genus of acanthocephalans mainly parasitic in various strigiform and falconiform birds. Some species of Centrorhynchus have not been adequately described. Here, the detailed morphology of C. clitorideus (Meyer, 1931) was studied using light and, for the first time, scanning electron microscopy, based on newly collected specimens from the little owl Athene noctua (Scopoli) (Strigiformes: Strigidae) in Pakistan. Partial sequences of the 18S and 28S nuclear ribosomal RNA genes and the mitochondrial cytochrome c oxidase subunit 1 (cox1) of C. clitorideus were generated for the first time. No nucleotide variation was detected for the partial 18S and 28S regions, but 3.30% of intraspecific nucleotide divergence was found for the cox1 gene. Phylogenetic analyses based on 28S and 18S sequence data showed that C. clitorideus formed a sister relationship with Centrorhynchus sp. MGV-2005 or Centrorhynchus sp. MGV-2005 + C. microcephalus (Bravo-Hollis, 1947), respectively.


Assuntos
Acantocéfalos/classificação , Estrigiformes/parasitologia , Acantocéfalos/genética , Acantocéfalos/ultraestrutura , Animais , DNA de Helmintos/genética , Microscopia Eletrônica de Varredura , Paquistão , Filogenia , Especificidade da Espécie
6.
Syst Parasitol ; 97(5): 455-476, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32794085

RESUMO

Three new species of the family Bucephalidae Poche, 1907 (Trematoda: Digenea) are described from the yellowtail pike, Sphyraena obtusata Cuvier (Sphyraenidae), from Moreton Bay, Queensland, Australia. The three species are morphologically consistent with the present broad concept of the genus Bucephalus Baer, 1827, but significant phylogenetic and ecological differences relative to the type-species of Bucephalus require the proposal of a new genus. Aenigmatrema n. g. is proposed for A. undecimtentaculatum n. sp. (type-species), A. inopinatum n. sp. and A. grandiovum n. sp. In addition, based on morphological, ecological and biogeographical similarities, we recombine two existing species of Bucephalus as Aenigmatrema kaku (Yamaguti, 1970) n. comb. and Aenigmatrema sphyraenae (Yamaguti, 1952) n. comb. Although the three species described in this study are extremely morphologically similar, they can be differentiated from each other, and from A. kaku and A. sphyraenae, morphometrically on the basis of egg size, tentacle number and a combination of the caecum and vitelline field lengths. Complete ITS2 rDNA, partial 28S rDNA and partial cox1 mtDNA sequence data were generated for the three new species, which formed a well-supported clade in all 28S phylogenetic analyses. An expanded phylogenetic tree for the subfamily Bucephalinae Poche, 1907 is presented, demonstrating unresolved issues with the morphology-based taxonomy of the subfamily. The three largest genera, Bucephalus, Rhipidocotyle Diesing, 1858 and Prosorhynchoides Dollfus, 1929 remain extensively polyphyletic, indicating the need for significant further systematic revision.


Assuntos
Esocidae/parasitologia , Filogenia , Trematódeos/classificação , Animais , DNA de Helmintos/genética , Queensland , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/genética
7.
Syst Parasitol ; 97(5): 501-516, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32794086

RESUMO

Two species of microcotylid monogeneans, Microcotyle caudata Goto, 1894 and Microcotyle sebastisci Yamaguti, 1958, have been reported from fishes of the Sebastes inermis species complex and Sebastiscus marmoratus (Cuvier) (Scorpaeniformes: Sebastidae). So far, these parasite species have been distinguished by the size of the eggs and the number of testes, but based on morphological evidence including re-examination of the type-specimens and topotypes and molecular analysis, we consider M. sebastisci to be a junior synonym of M. caudata. As a result, M. caudata exhibits a wide host range, seven species from three genera and two families. A new species, Microcotyle kasago n. sp., is described based on material from S. marmoratus and differentiated from other congeners by means of morphological and molecular analysis.


Assuntos
Brânquias/parasitologia , Perciformes/parasitologia , Trematódeos/classificação , Animais , DNA de Helmintos/genética , Japão , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/genética
8.
Syst Parasitol ; 97(5): 491-500, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32737666

RESUMO

Prior to the present study, species of the trematode family Monorchiidae Odhner, 1911 had been reported from four of the ten families of tetraodontiform fishes: the Balistidae, Monacanthidae, Ostraciidae and Tetraodontidae. Here we report the first monorchiid from the family Triacanthidae, Pseudohurleytrema yolandae n. sp. infecting Tripodichthys angustifrons (Hollard), from Moreton Bay, Queensland, Australia. The species conforms well to the morphological concept of the subfamily Hurleytrematinae Yamaguti, 1958, and the genus Pseudohurleytrema Yamaguti, 1954, in the possession of filamented eggs, a bipartite terminal organ, and a unipartite seminal vesicle. Relative to the other three recognised species of Pseudohurleytrema, the present species is distinctive in the size of the testis and eggs, position of the ovary, and the form of the vitellarium and excretory vesicle. We consider Pseudohurleytrema magnum Kaikabad & Bilqees in Bilqees, 1991 as a species inquirenda. Sequence data for the 28S ribosomal RNA gene and cox1 mitochondrial gene were generated for P. yolandae, providing the first molecular data for the genus. Phylogenetic analysis showed that P. yolandae does not form a clade with the other three hurleytrematine genera for which there are molecular data (Helicometroides Yamaguti, 1934, Hurleytrematoides Yamaguti, 1953 and Provitellus Dove & Cribb, 1998), forming a poorly-supported clade with Proctotrema addisoni Searle, Cutmore & Cribb, 2014 within the clade of the subfamily Monorchiinae Odhner, 1911. The four hurleytrematine genera resolved as four distinct clades, indicating that the current subfamilial classification requires comprehensive revision.


Assuntos
Tetraodontiformes/parasitologia , Trematódeos/classificação , Animais , Baías , DNA de Helmintos/genética , Filogenia , Queensland , RNA Ribossômico 28S/genética , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/genética
9.
Rev Bras Parasitol Vet ; 29(3): e009620, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32667498

RESUMO

Specimens of Oncicola venezuelensis (Marteau, 1977) were recovered from fragments of intestinal tissue of a female Puma concolar (Linn, 1771) found dead in Petrópolis, Rio de Janeiro in 2017. A total of 140 helminths were recovered. Five males and 5 females of the helminths were analyzed morphologically as well as 50 parasite eggs recovered in intestinal contents. Morphologically, these helminths were compatible with the genus Oncicola, because of the size and shape of the proboscis, the size and disposition of the lemnisci and the morphometry of the eggs, in which the external membrane of the shell was delicate and clear. From histopathology, the helminths were deeply embeded in the mucosa reaching up to the muscle layer. One specimen was also identified molecularly with universal primers that amplified the eukaryote region ITS1-5.8S-ITS2. The helminth showed 99% identity with the gene sequence of O. venezuelensis deposited in GenBank. It is important to emphasize, this parasite has been very little reported in the literature, which reinforces the importance of this report.


Assuntos
Acantocéfalos , Puma , Acantocéfalos/classificação , Acantocéfalos/genética , Animais , Brasil , DNA de Helmintos/genética , Feminino , Masculino , Puma/parasitologia
10.
Mem Inst Oswaldo Cruz ; 115: e200115, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32638831

RESUMO

In January and February 2019, a malacological survey was conducted in the area surrounding the residence of a 12-year-old child that had contracted cerebral angiostrongyliasis in the municipality of Macapá, capital of the Amapá State, northern Brazil. The serological examination was positive for Angiostrongylus cantonensis infection, the principal etiological agent of this parasitosis. A sample of 54 molluscs was artificially and individually digested for parasitological analysis, containing 38 specimens of Achatina fulica, nine specimens of Bulimulus tenuissimus and seven specimens of Sarasinula linguaeformis. A. fulica was the most abundant mollusc, and the only species infected with A. cantonensis, as well as presenting co-infections with other nematodes. This is the first report of cerebral angiostrongyliasis in the Amazon Region, and the first record of A. fulica infected with A. cantonensis in Amapá. These findings highlight the potential risks of human angiostrongyliasis, and the need to implement public health measures to control the spread of the disease.


Assuntos
Angiostrongylus cantonensis/isolamento & purificação , Caramujos/parasitologia , Infecções por Strongylida/diagnóstico , Infecções por Strongylida/veterinária , Animais , Anticorpos Anti-Helmínticos , Brasil , Criança , Cidades , DNA de Helmintos/química , DNA de Helmintos/genética , Humanos , Infecções por Strongylida/parasitologia
11.
Rev Bras Parasitol Vet ; 29(3): e005120, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32638835

RESUMO

Siganids are the most important marine fish distributed along the African coast. Therefore, the current study aimed to investigate parasite fauna infects one of the most important mariculture fish species in the Red Sea, the Rabbit fish Siganus rivulatus. One acanthocephalan species has been isolated from the posterior region of fish intestine, belonging to the Neoechinorhynchidae family, and named as Neoechinorhynchus macrospinosus Amin & Nahhas, 1994 based on its morphological and morphometric features. In order to determine the accurate taxonomic position of this acanthocephalan species, molecular phylogenetic analysis was carried out based on the partial sequences of 18S rDNA gene region. The obtained data revealed that this species was associated with a close identity ˃71% for other species belonging to the Neoechinorhynchidae family. In addition, the recovered species deeply embedded in the Neoechinorhynchus genus, closely related to the previously described Neoechinorhynchus sp., N. mexicoensis, and N. golvani with identity percent of 95.14, 93.59, 93.59%, respectively. Therefore, the present study provide a better understanding about the taxonomic status of N. macrospinosus based on 18S rDNA that can be useful for achieving a proper assessment of biodiversity.


Assuntos
Acantocéfalos , Doenças dos Peixes , Helmintíase Animal , Filogenia , Acantocéfalos/anatomia & histologia , Acantocéfalos/classificação , Acantocéfalos/genética , Animais , DNA de Helmintos/genética , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , RNA Ribossômico 18S/genética
12.
Syst Parasitol ; 97(5): 477-490, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32691325

RESUMO

Previous phylogenetic analyses of the Acanthocephala have demonstrated that the families Rhadinorhynchidae Lühe, 1912 and Transvenidae Pichelin & Cribb, 2001 are sister clades. However, a recent study found that the Rhadinorhynchidae is paraphyletic, due to the basal position of Rhadinorhynchus biformis Smales, 2014 relative to the Rhadinorhynchidae + Transvenidae. We reassess these relationships with new single-gene and concatenated phylogenetic analyses utilising cox1 mtDNA, 18S rDNA and 28S rDNA, including recently available sequences. Although topologies differed among single-gene analyses, the overall results support R. biformis as representative of a lineage distinct from those of the Rhadinorhynchidae and Transvenidae. Examination of additional specimens of R. biformis allowed us to identify morphological characters that further support this hypothesis. These results lead us to propose transfer of R. biformis to a new genus (Spinulacorpus n. g.) and family (Spinulacorpidae n. fam.) to resolve the paraphyly of the Rhadinorhynchidae.


Assuntos
Acantocéfalos/classificação , Filogenia , Acantocéfalos/anatomia & histologia , Acantocéfalos/genética , Animais , DNA de Helmintos/genética , Especificidade da Espécie
13.
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
14.
PLoS Negl Trop Dis ; 14(6): e0008392, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32542036

RESUMO

The canine hookworms Ancylostoma braziliense, Ancylostoma ceylanicum, Ancylostoma caninum and Uncinaria stenocephala are not only capable of producing morbidity and mortality in dogs but are also neglected tropical zoonoses. Each hookworm species differs considerably in its geographical distribution, life cycle, biology, pathogenic impacts on both canine and human hosts, zoonotic potential, and response to treatment with anthelminthics. Here we describe the development and validation of two Taq-Man based multiplex PCR assays capable of detecting and differentiating all four canine hookworm species in faeces of naturally infected dogs. The analytical sensitivity of both assays was assessed using 10-fold serial dilutions of synthetic gene block fragments containing individual sequence targets of each hookworm species. The sensitivity of the assays and ability to detect mixed species infections were compared to a conventional PCR-Restriction Fragment Length Polymorphism based-approach when applied to laboratory and field samples from endemic areas. The qPCRs detected at least one species of hookworms in 82.4% of PCR-RFLP-negative but microscopy-positive samples. The qPCRs detected an additional 68% mixed infections with different species of canine hookworms, and additional single species infection with A. caninum (47%), U. stenocephala (33%) and A. ceylanicum (0.02%) that were missed by PCR-RFLP. These multiplex qPCR assays will assist field based epidemiological surveillance studies towards an accurate and sensitive monitoring of canine hookworm infections in dogs, to inform their species-specific zoonotic risks to populations living in endemic areas, globally.


Assuntos
Ancylostomatoidea/genética , Ancylostomatoidea/isolamento & purificação , Doenças do Cão/diagnóstico , Infecções por Uncinaria/diagnóstico , Reação em Cadeia da Polimerase Multiplex/métodos , Reação em Cadeia da Polimerase Multiplex/veterinária , Ancylostoma/genética , Ancylostoma/isolamento & purificação , Ancylostomatoidea/classificação , Ancilostomíase/diagnóstico , Ancilostomíase/epidemiologia , Ancilostomíase/fisiopatologia , Animais , DNA de Helmintos/análise , DNA de Helmintos/genética , Doenças do Cão/epidemiologia , Doenças do Cão/fisiopatologia , Cães , Fezes/parasitologia , Infecções por Uncinaria/fisiopatologia , Humanos , Polimorfismo de Fragmento de Restrição , Sensibilidade e Especificidade , Zoonoses/diagnóstico , Zoonoses/epidemiologia , Zoonoses/fisiopatologia
15.
PLoS One ; 15(6): e0234116, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32544162

RESUMO

Changes in parasite communities might result in new host-parasite dynamics and may threaten local fish populations. This phenomenon has been suggested for acanthocephalan parasites in the river Rhine and Danube where the species Pomphorhynchus tereticollis is becoming replaced by the Ponto-Caspian P. laevis. Developing knowledge on morphologic, genetic and behavioural differences between such species is important to follow such changes. However, disagreements on the current phylogeny of these two acanthocephalan species are producing conflicts that is affecting their correct identification. This study is offering a clearer morphological and genetic distinction between these two species. As P. tereticollis is found in rhithral tributaries of the Rhine, it was questioned whether the local salmonid populations were hosts for this species and whether P. laevis was expanding into the Rhine watershed as well. In order to test for this, brown trout, Salmo trutta, and grayling, Thymallus thymallus from South-Western Germany watersheds have been samples and screened for the occurrence of acanthocephalan parasites. For the first time, both species were confirmed to be hosts for P. tereticollis in continental Europe. P. tereticollis was found to be common, whereas P. leavis was found only at a single location in the Danube. This pattern suggest either that the expansion of P. laevis through salmonid hosts into rhithral rivers has not yet occurred, or that not yet ascertained biotic or abiotic features of rhithral rivers hinder P. laevis to spread into these areas.


Assuntos
Acantocéfalos/genética , Doenças dos Peixes/parasitologia , Salmonidae/parasitologia , Acantocéfalos/anatomia & histologia , Acantocéfalos/classificação , Animais , DNA de Helmintos/genética , DNA de Helmintos/metabolismo , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/patologia , Alemanha/epidemiologia , Microscopia Eletrônica de Varredura , Filogenia , Prevalência , Truta/parasitologia
16.
Parasitol Res ; 119(6): 1713-1728, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32405803

RESUMO

In this study, we followed an integrative taxonomy approach to describe two new species of Gyrodactylus von Nordmann, 1832, and to identify specimens of G. breviradix Vega, Razzolini, Arbetman, and Viozzi, 2019, all three collected from ten spotted live-bearer Cnesterodon decemmaculatus (Jenyns, 1842), an endemic and widespread poeciliid from the Pampean region, which is the southernmost occurring species of the Poeciliidae in the Americas. Gyrodactylids were first characterized morphologically and mophometrically, and when possible, sequences of the Internal Transcribed Spacers (ITS1-5.8S-ITS2) and the cytochrome oxidase II (COII) were used to delimit species. Gyrodactylus breviradix, Gyrodactylus marplatensis n. sp., and Gyrodactylus pampeanus n. sp. were found on the fins and body surface of C. decemmaculatus in La Tapera Creek, Mar del Plata, Buenos Aires province, Argentina. A phylogenetic analysis combining newly generated sequences of one of the new species, G. marplatensis n. sp., and of G. breviradix, along with those available in GenBank for a further 36 species of Gyrodactylus, revealed that G. marplatensis n. sp. is a sister taxon of Gyrodactylus decemmaculati Vega, Razzolini, Arbetman, and Viozzi, 2019. Genetic distances for the ITS and COII gene were estimated among Gyrodactylus spp. and further supported the validity of the new species. Overall, morphometric and molecular data coincided in delimiting the new taxa, thus demonstrating the value of integrative taxonomy for the erection of new species of Gyrodactylus and species identification.


Assuntos
Ciprinodontiformes/parasitologia , Doenças dos Peixes/parasitologia , Trematódeos/classificação , Animais , Argentina , DNA de Helmintos/genética , DNA Espaçador Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/genética
17.
Parasitol Res ; 119(6): 1803-1817, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32372130

RESUMO

Lungworms of the genera Parafilaroides and Otostrongylus are responsible for parasitic bronchopneumonia, the foremost disease of eastern Atlantic common seals (EACS, Phoca vitulina vitulina) in the Dutch North Sea. Recently, there have been increased reports of lungworm cases and observations of unusually long Parafilaroides sp. adults in this location. The initial aim of this study was to confirm the identity of the Parafilaroides species infecting this population. Parafilaroides are usually small and delicate, making them difficult to extract from host tissue, and there is often difficulty accessing fresh specimens for morphological study. The large size of the Dutch worms and the accessibility of specimens from numerous animals enabled the description and measurement of many intact specimens (N = 64) from multiple host animals (N = 20). Species identity was confirmed by targeted sequencing of ribosomal and mitochondrial DNA amplicons from a subset of worms. Worm morphology was consistent with descriptions for P. gymnurus, but the mature females were 1.9-fold and 3.4-fold longer than those recovered from French EACS (P ≤ 0.001) and Canadian western Atlantic common seals (Phoca vitulina concolor; P ≤ 0.0001). They were also significantly longer than mature female P. gymnurus described from other seal species, with the exception of those from harp seals of Les Escoumins, Quebec. We suggest that intraspecific genetic differences in P. gymnurus and the environment within the host could contribute to the variation reported here. This study is the first to describe P. gymnurus using morphological and molecular methods and should serve as a reference for identification of the species.


Assuntos
Pulmão/parasitologia , Metastrongyloidea/anatomia & histologia , Metastrongyloidea/classificação , Phoca/parasitologia , Infecções por Strongylida/veterinária , Animais , DNA de Helmintos/genética , DNA Mitocondrial/genética , DNA Ribossômico/genética , Feminino , Especificidade de Hospedeiro , Metastrongyloidea/genética , Metastrongyloidea/isolamento & purificação , Países Baixos , Mar do Norte , Focas Verdadeiras/parasitologia , Análise de Sequência de DNA , Infecções por Strongylida/parasitologia
18.
Parasitol Res ; 119(6): 1795-1802, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32335727

RESUMO

Species of Cosmocerca Diesing, 1861 (Ascaridomorpha: Cosmocercoidea), are common nematode parasites of amphibians. In the present study, a new species of Cosmocerca, namely C. simile n. sp., was described using light and scanning electron microscopy, and sequencing different nuclear and mitochondrial genetic markers (i.e. small ribosomal DNA (18S), large ribosomal DNA (28S), internal transcribed spacer (ITS) and cytochrome c oxidase subunit 1 (cox1)). Cosmocerca simile n. sp. differs from its congeners based on body size, morphology and number of plectanes, relative length of spicules and gubernaculum and spicules to total body length and morphology and length of tail. Molecular analysis showed no nucleotide polymorphisms among different individuals of the new species regarding nuclear DNA. Very low intraspecific nucleotide variation (0.52-0.78%) was detected in cox1 mtDNA. In contrast, the level of interspecific nucleotide variation between C. simile n. sp. and its congeners were distinctly higher (2.74-18.1% in the partial ITS region and 10.2-13.5% in the partial cox1 region, respectively) than that of intraspecific variation. Phylogenetic analyses using maximum likelihood (ML) inference based on the partial ITS and cox1 sequence data both supported the new species to be a member of the genus Cosmocerca, and formed a sister relationship to C. japonica. The newly obtained genetic data are important for further studies of DNA-based taxonomy, population genetics and phylogenetics of the Cosmocercoidea.


Assuntos
Ascaridídios/classificação , Bufonidae/parasitologia , Filogenia , Animais , Ascaridídios/anatomia & histologia , Ascaridídios/genética , Ciclo-Oxigenase 1/genética , DNA de Helmintos/genética , DNA Mitocondrial/genética , DNA Ribossômico/genética , Análise de Sequência de DNA , Especificidade da Espécie
19.
PLoS Negl Trop Dis ; 14(4): e0008087, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32330127

RESUMO

There is growing interest in local elimination of soil-transmitted helminth (STH) infection in endemic settings. In such settings, highly sensitive diagnostics are needed to detect STH infection. We compared double-slide Kato-Katz, the most commonly used copromicroscopic detection method, to multi-parallel quantitative polymerase chain reaction (qPCR) in 2,799 stool samples from children aged 2-12 years in a setting in rural Bangladesh with predominantly low STH infection intensity. We estimated the sensitivity and specificity of each diagnostic using Bayesian latent class analysis. Compared to double-slide Kato-Katz, STH prevalence using qPCR was almost 3-fold higher for hookworm species and nearly 2-fold higher for Trichuris trichiura. Ascaris lumbricoides prevalence was lower using qPCR, and 26% of samples classified as A. lumbricoides positive by Kato-Katz were negative by qPCR. Amplicon sequencing of the 18S rDNA from 10 samples confirmed that A. lumbricoides was absent in samples classified as positive by Kato-Katz and negative by qPCR. The sensitivity of Kato-Katz was 49% for A. lumbricoides, 32% for hookworm, and 52% for T. trichiura; the sensitivity of qPCR was 79% for A. lumbricoides, 93% for hookworm, and 90% for T. trichiura. Specificity was ≥ 97% for both tests for all STH except for Kato-Katz for A. lumbricoides (specificity = 68%). There were moderate negative, monotonic correlations between qPCR cycle quantification values and eggs per gram quantified by Kato-Katz. While it is widely assumed that double-slide Kato-Katz has few false positives, our results indicate otherwise and highlight inherent limitations of the Kato-Katz technique. qPCR had higher sensitivity than Kato-Katz in this low intensity infection setting.


Assuntos
Helmintíase/diagnóstico , Enteropatias Parasitárias/diagnóstico , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Ancylostomatoidea/isolamento & purificação , Animais , Ascaris lumbricoides/isolamento & purificação , Bangladesh , Criança , Pré-Escolar , DNA de Helmintos/genética , DNA Ribossômico/genética , Fezes/parasitologia , Feminino , Humanos , Lactente , Masculino , RNA Ribossômico 18S/genética , População Rural , Sensibilidade e Especificidade , Trichuris/isolamento & purificação
20.
Parasitol Res ; 119(6): 1785-1793, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32318808

RESUMO

A new species of microphallid trematode was collected from the intestine of the yellow-crowned night heron Nyctanassa violacea (L.) (Pelecaniformes: Ardeidae) from Veracruz, Mexico. Maritrema kostadinovae n. sp. differs distinctly from other members of Maritrema Nicoll, 1907 from the Americas by its smaller body size (262-435 × 242-363 µm), the extension of caeca (reaching to anterior level of ventral sucker), the size and shape of the cirrus (short, tubular and unarmed) and metraterm (simple and thin-walled), the position of the genital pore (sinistrolateral to ventral sucker) and the arrangement of the vitellaria (horseshoe-shaped with posteriorly directed opening). Maximum likelihood and Bayesian inference analyses, based on partial 28S rDNA sequences, depicted M. kostadinovae n. sp. within the genus Maritrema with strong support. The new species is in a sister position to other available members of Maritrema, except for M. subdolum Jägerskiöld, 1909 that branches as the early divergent species in the Maritrema clade. The new species is the third species of Maritrema described from birds in Mexico. Comparative morphometric data for Maritrema taxa from birds and mammals from the Americas is provided.


Assuntos
Aves/parasitologia , Filogenia , Trematódeos/anatomia & histologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , DNA de Helmintos/genética , DNA Ribossômico/genética , México , Especificidade da Espécie , Trematódeos/genética , Infecções por Trematódeos/parasitologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA