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1.
Folia Parasitol (Praha) ; 712024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39078212

RESUMO

The present paper comprises a systematic survey of helminths (trematodes, an acanthocephalan and nematodes) found in nine species of freshwater fishes in Ecuador collected in March 1999 and those (a trematode and acanthocephalans) collected from an amphibian and two species of freshwater fishes in Venezuela in 1992, 1996 and 2001. The following 17 helminth species were recorded: Trematoda: Prosthenhystera ornamentosa sp. n., P. obesa (Diesing, 1850), Crassicutis intermedius (Szidat, 1954), C. cichlasomae Manter, 1936 and Glypthelmins eleutherodactyli sp. n. Acanthocephala: Quadrigyrus torquatus Van Cleave, 1920, Gracilisentis variabilis (Diesing, 1851) and Neoechinorhynchus (Neoechinorhynchus) ecuadoris sp. n. Nematoda: Cosmoxynema vianai Travassos, 1949, Travnema travnema Pereira, 1938, Touzeta ecuadoris Petter, 1987, Sprentascaris hypostomi Petter et Cassone, 1984, Sprentascaris sp., Contracaecum sp. Type 1 larvae, Contracaecum sp. Type 2 larvae, Procamallanus (Procamallanus) peraccuratus Pinto, Noronha et Rolas, 1976 and Procamallanus (Spirocamallanus) sp. juv. Nearly all of these parasites are reported from Ecuador or Venezuela for the first time and many of these findings represent new host records. The new species P. ornamentosa sp. n. was collected from the gall-bladder of an unidentified anostomid (Anostomidae, Characiformes) in Ecuador, G. eleutherodactyli sp. n. from the digestive tract of the frog Eleutherodactylus sp. (Eleutherodactylidae, Anura) in Venezuela and N. (N.) ecuadoris sp. n. from the intestine of Lebiasina sp. (Lebiasinidae, Characiformes) in Ecuador. Most parasites are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed.


Assuntos
Anfíbios , Doenças dos Peixes , Peixes , Água Doce , Helmintíase Animal , Helmintos , Animais , Venezuela/epidemiologia , Equador/epidemiologia , Peixes/parasitologia , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Anfíbios/parasitologia , Helmintos/classificação , Helmintos/isolamento & purificação , Doenças dos Peixes/parasitologia , Doenças dos Peixes/epidemiologia
2.
Parasitol Res ; 123(7): 270, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38995430

RESUMO

The construction of dams and hydroelectric plants affects biodiversity in aquatic environments and can facilitate the invasion of species. Few studies assess the long-term response of parasite fauna under these events. The aim of this study was to investigate possible changes in the endoparasite composition of the invasive catfish Trachelyopterus galeatus (Linnaeus, 1766) in the floodplain of the upper Paraná River over a 27-year study period. A total of 79 fish were collected in period 1 (1993) and 31 in period 2 (2019/2020) at the same sampling points, and the endoparasites were located in the gastrointestinal system using a stereomicroscope. It was found that the development of the fish and the composition of their endoparasitic fauna changed over time. In the second period, the fish presented smaller values for mass (g) and standard length (cm) when compared to period 1. It was found that three species of endoparasites were found per period, but although the richness was the same, the composition differed, and only one digenean (Microrchis oligovitellum Lunaschi, 1987 (Trematoda: Paramphistomidae)) was shared. The Porto Primavera Dam was built upstream of the site between the sampling periods (1999) and caused a number of environmental changes, possibly being the main factor responsible for changes in components of the parasite community. Anthropic modification to an environment can cause loss of diversity and loss of ecological interactions. Through our results, we emphasize the importance of including parasite fauna in studies that assess environmental impacts.


Assuntos
Peixes-Gato , Doenças dos Peixes , Espécies Introduzidas , Rios , Animais , Peixes-Gato/parasitologia , Doenças dos Peixes/parasitologia , Brasil , Rios/parasitologia , Biodiversidade , Parasitos/isolamento & purificação , Parasitos/classificação , Parasitos/fisiologia
3.
Vet Parasitol Reg Stud Reports ; 53: 101066, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39025540

RESUMO

Cuniculus paca, commonly known as the paca, is a rodent of the Cuniculidae family that is widely distributed throughout the Americas, including all Brazilian territories, and is abundant in the Amazon region. It is one of the most hunted species and faces significant predation in the extreme western Amazon region of Brazil because it constitutes a staple in the diet of local communities, for subsistence and commercial purposes. Understanding the helminthic fauna of these animals is of paramount importance, given that some nematodes have zoonotic potential and may pose risks to consumer health. This study aimed to contribute to the records of the nemtodes of this highly consumed species in the Amazon region, highlighting the occurrence of gastrointestinal parasites in free-living pacas intended for human subsistence consumption. The study was conducted in the Paranã da Floresta community, located in the municipality of Guajará, Amazonas from 2022 to 2023. The community members hunted this rodent for consumption and voluntarily provided the viscera for analysis. Nematodes were extracted from each organ. The organs were opened, and the contents were processed using a sieve (0.15 mm) and subsequently evaluated separately. In total, 10,157 nematodes were found in the 14 pacas. Based on morphological analyses, the nematodes were identified as Heligmostrongylus sedecimradiatus (n = 10,068), Trichuris sp. (n = 85), and Physaloptera sp. (n = 4). This study provides insights into the nematodes diversity of free-living pacas in the extreme Western Amazon region, emphasizing the importance of sanitary surveillance and public awareness of the risks associated with bushmeat consumption.


Assuntos
Nematoides , Infecções por Nematoides , Animais , Brasil/epidemiologia , Nematoides/isolamento & purificação , Nematoides/classificação , Infecções por Nematoides/veterinária , Infecções por Nematoides/parasitologia , Infecções por Nematoides/epidemiologia , Cuniculidae/parasitologia , Masculino , Feminino , Doenças dos Roedores/parasitologia , Doenças dos Roedores/epidemiologia , Humanos
4.
Parasitol Res ; 123(6): 244, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38878081

RESUMO

We describe the composition of endoparasites associated with leaf litter anurans from an Atlantic Forest area, in southeastern Brazil. We tested if body size, sex, and reproductive modes of anuran hosts influence endoparasite abundance and richness. We sampled 583 individuals from 11 anuran species and recorded 1,600 helminths from 14 taxa. The helminths that infected the greatest number of anuran host species were the nematodes Cosmocerca parva (8 spp.), Physaloptera sp. (8 spp.), and Cosmocerca brasiliense (7 spp.), and the most abundant helminth species were Physaloptera sp. (14.6%), Cosmocerca brasiliense (13.7%) and Cosmocerca parva (12.6%). Both helminth abundance and richness were positively affected by anuran body size and dependence on water for reproduction. Larger hosts can contain a higher abundance of parasites because they may provide more physical space than smaller ones, or it can simply be a function of age. Besides, parasite species richness can be highly correlated with the amount of time a host spends in association with aquatic habitats, a conservative aspect of both parasite and host natural history. Within host species, there was a positive and significant influence of body size on helminth abundance. Haddadus binotatus females had greater helminth abundance than males, probably due to sex-related differences in behavior and/or in physiology. Our data suggest that reproductive modes could also influence helminth infection parameters in other anuran communities and should be considered in detail in future analyses.


Assuntos
Anuros , Tamanho Corporal , Helmintos , Reprodução , Animais , Anuros/parasitologia , Brasil , Feminino , Masculino , Helmintos/classificação , Helmintos/fisiologia , Helmintos/isolamento & purificação , Biodiversidade , Interações Hospedeiro-Parasita
5.
J Helminthol ; 98: e30, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38584420

RESUMO

Six species of freshwater turtles dominate the Chaco-Pampa Plain in southern South America and their parasites have been relatively understudied, with most records concentrated in Brazil. Particularly in Argentina, there are only scattered records of parasites for most of the turtles that inhabit the region, leaving a large knowledge gap. The purpose of the present contribution is to increase the knowledge of the internal parasites of six species of freshwater turtles from Argentina, after 15 years of fieldwork, by providing new hosts and additional geographic records for many host-parasite relationships. Some molecular sequences of the studied parasites were provided as a tool for better species identification. We processed 433 stomach and fecal samples from live individuals and visceral and soft tissue samples from 54 dissected turtles collected from a wide range and different ecoregions. We found 6230 helminths belonging to 18 taxa (one cestode, 11 digeneans and six nematodes). Fourteen new parasite-host associations are reported here, and for the first time parasites are recorded for Phrynops williamsi. This work contributes significantly to the knowledge of the parasitofauna in freshwater turtles in Argentina, providing a detailed list of parasites present in each turtle species and reporting molecular characters for future studies.


Assuntos
Helmintos , Parasitos , Tartarugas , Animais , Tartarugas/parasitologia , Helmintos/genética , Água Doce , Brasil
6.
J Parasitol ; 110(2): 114-126, 2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38503317

RESUMO

An inventory of parasites infecting the jaguar (Panthera onca) across its distribution range is relevant for the conservation of this threatened big cat. In this study, we report the occurrence of helminths in a jaguar from Mexico using morphological techniques (cleared and stained mounts and scanning electron microscopy) and partial sequences of the 28S ribosomal RNA (28S rRNA) gene and the cytochrome c oxidase 1 mitochondrial (COI) gene. We also provide an updated list of helminth species reported in jaguars in the Americas. Three helminth taxa are identified in the jaguar examined from Mexico: Toxocara cati, Physaloptera sp., and Taenia sp. The new 28S rRNA sequences of To. cati, Physaloptera sp., and Taenia sp. and the COI sequence of Taenia sp. corroborate the identity of the helminths isolated from this host. One hundred and twenty-nine records of helminths parasitizing jaguars from 49 studies up to May 2023 were identified in the Americas. In most of these studies (73.6%), helminths were identified using coproparasitological techniques. Sixteen helminths (7 nematodes, 5 cestodes, 3 acanthocephalans, and 1 trematode) were identified at the species level in free-ranging and captive jaguars. The study demonstrates the value of an integrative taxonomy approach to increase the accuracy of parasite identification in wildlife, especially when helminth specimens are scarce or poorly fixed.


Assuntos
Helmintos , Nematoides , Panthera , Animais , Panthera/genética , México/epidemiologia , RNA Ribossômico 28S/genética , Helmintos/genética
7.
Rev. bras. parasitol. vet ; 33(2): e000124, 2024. tab
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1565404

RESUMO

Abstract Astyanax lacustris is a small characid fish widely distributed in Brazil, with fast-growing and omnivorous feeding habits. Although the species presents economic and ecological importance, little is known about its parasitological fauna in stream environments. This study aimed to characterize the parasitic fauna of A. lacustris in two streams in the state of Paraná, Brazil. Fifty-two specimens of A. lacustris were collected, 22 from the Carolina stream (Lower Iguaçu River) and 30 from the Carreira stream (Upper Paraná River), in July and September 2018. In both streams, there was a low richness of parasites, and the structure of the parasitic community was predominantly composed of monogeneans. These findings may be associated with the gregarious behavior of the host species. Moreover, the low occurrence of endohelminths, may be associated with the fact that in streams, the energy flow is low, and depends directly on the input of allochthonous matter, which favors the formation of shelters for the establishment of macroinvertebrates, which represent important sources of food for the ichthyofauna, and may act as intermediate and paratenic hosts of parasites. These environments require further studies to support conservation measures aimed at maintaining the balance of ecological relationships in these preserved ecosystems.


Resumo Astyanax lacustris é um caracídeo de pequeno porte, amplamente distribuído no Brasil, com hábito alimentar onívoro e rápido crescimento. Embora a espécie tenha importância econômica, pouco se sabe sobre sua fauna parasitológica em ambientes de riacho. Este estudo objetivou caracterizar a fauna parasitária de A. lacustris em dois riachos do estado do Paraná. Foram coletados 52 exemplares de A. lacustris, sendo 22 no riacho Carolina (baixo rio Iguaçu) e 30 no riacho Carreira (alto rio Paraná), nos meses de julho e setembro de 2018. Em ambos os riachos, houve baixa riqueza de parasitos e a estrutura da comunidade parasitária foi caracterizada pela predominância de monogenéticos. Esses achados podem estar associados ao comportamento gregário da espécie hospedeira. Ademais, a baixa ocorrência de endohelmintos pode estar associada ao fato de que, nos riachos, o fluxo de energia é baixo e depende diretamente do aporte de matéria alóctone, que favorece a formação de abrigos para o estabelecimento de macroinvertebrados, os quais representam uma das principais fontes de alimento da ictiofauna, e podem atuar como hospedeiros intermediários e paratênicos de parasitos. Esses ambientes necessitam de mais estudos para subsidiar medidas de conservação que visem manter o equilíbrio das relações ecológicas nesses ecossistemas preservados.

8.
PeerJ ; 11: e16216, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37842061

RESUMO

Background: Identifying species, particularly small metazoans, remains a daunting challenge and the phylum Nematoda is no exception. Typically, nematode species are differentiated based on morphometry and the presence or absence of certain characters. However, recent advances in artificial intelligence, particularly machine learning (ML) algorithms, offer promising solutions for automating species identification, mostly in taxonomically complex groups. By training ML models with extensive datasets of accurately identified specimens, the models can learn to recognize patterns in nematodes' morphological and morphometric features. This enables them to make precise identifications of newly encountered individuals. Implementing ML algorithms can improve the speed and accuracy of species identification and allow researchers to efficiently process vast amounts of data. Furthermore, it empowers non-taxonomists to make reliable identifications. The objective of this study is to evaluate the performance of ML algorithms in identifying species of free-living marine nematodes, focusing on two well-known genera: Acantholaimus Allgén, 1933 and Sabatieria Rouville, 1903. Methods: A total of 40 species of Acantholaimus and 60 species of Sabatieria were considered. The measurements and identifications were obtained from the original publications of species for both genera, this compilation included information regarding the presence or absence of specific characters, as well as morphometric data. To assess the performance of the species identification four ML algorithms were employed: Random Forest (RF), Stochastic Gradient Boosting (SGBoost), Support Vector Machine (SVM) with both linear and radial kernels, and K-nearest neighbor (KNN) algorithms. Results: For both genera, the random forest (RF) algorithm demonstrated the highest accuracy in correctly classifying specimens into their respective species, achieving an accuracy rate of 93% for Acantholaimus and 100% for Sabatieria, only a single individual from Acantholaimus of the test data was misclassified. Conclusion: These results highlight the overall effectiveness of ML algorithms in species identification. Moreover, it demonstrates that the identification of marine nematodes can be automated, optimizing biodiversity and ecological studies, as well as turning species identification more accessible, efficient, and scalable. Ultimately it will contribute to our understanding and conservation of biodiversity.


Assuntos
Inteligência Artificial , Nematoides , Humanos , Animais , Algoritmos , Aprendizado de Máquina , Cromadoria
9.
J Helminthol ; 97: e58, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37476963

RESUMO

Marmosa constantiae is a species of marsupial restricted to the central portion of South America. In Brazil, it occurs in the northwestern region including five states of the Amazon, Cerrado, and Pantanal biomes. However, there is no study of the helminth fauna or helminth community structure for this marsupial. The aims of this study were to describe the species composition and to analyse the structure of the helminthic community of M. constantiae in an area of the Amazon Arc in Sinop, north of the state of Mato Grosso, Brazil. Parasites were searched in 53 specimens of this marsupial, among which 44 were infected with at least one helminth species. Parasitic helminths were counted and identified. Nine species were collected: seven nematodes, one cestode, and one acanthocephalan. The most abundant species were Gracilioxyuris agilisis, Travassostrongylus scheibelorum, Pterygodermatites sinopiensis, and Subulura eliseae. These species were the only dominant ones in the component community. No significant differences were observed in the abundance and prevalence of helminths between male and female hosts. Host body size significantly influenced helminth abundance in males. The pattern of community structure considering the infracommunities in this locality indicated more species replacement than species loss along the environmental gradient. This is the first study to report the helminth fauna and the helminth community structure of M. constantiae.


Assuntos
Helmintíase Animal , Helmintos , Marsupiais , Feminino , Masculino , Camundongos , Animais , Brasil/epidemiologia , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Gambás/parasitologia
10.
Helminthologia ; 60(1): 112-116, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37305669

RESUMO

Gnathostomiasis in humans is acquired by consumption of any infected second intermediate host or paratenic host. This includes amphibians, snakes and poultry as well as fish. In this work we report for the first time in Mexico the presence of an AdvL3 of Gnathostoma turgidum in the musculature of a wild fish (Gobiomorus dormitor, which also acts as intermediate host for the larvae of G. binucleatum and G. lamothei), from the Papaloapan River, Veracruz; previously, larvae of G. turgidum had only been recorded in amphibians in Mexico and in wild swamp eels from Tampa, Florida, USA. The larva found is extremely small (approximately 1,500 by 140 microns in length and width, respectively), and was obtained by artificial digestion with pepsin after examining the musculature against the light between two glass plates, a method by which it went unnoticed. Our finding of an AdvL3 in this fish, together with a previous molecular phylogenetic analysis revealing that the five species involved in human infections do not nest in the same clade, suggest that all species in the genus are potentially zoonotic. In this context, we strongly recommend the identification of larvae extracted from human patients at specific level, in order to know the role played by the 3 species distributed in Mexico in human cases of gnathostomiasis.

11.
J Parasitol ; 109(3): 181-186, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37225665

RESUMO

The monotypic genus PneumoatractisBursey, Reavill, and Greiner, 2009 was erected to allocate nematodes collected from the lungs of the freshwater turtle Podocnemis unifilis Troschel. During a helminthological survey of parasites from freshwater turtles of Tocantins and Xingu rivers, Pará State, eastern Amazon, Brazil, we found nematodes parasitizing the stomach and large intestine of Po. unifilis and Podocnemis expansa Schweigger. We assigned them to a new species of Pneumoatractis, which is described herein. Pneumoatractis gibbonsae n. sp. resembles Pneumoatractis podocnemis by the morphology of the oral opening, the position of the excretory pore, and the lanceolate shape of the spicules, but differs from it in males by having 10 pairs of caudal papillae plus 1 unpaired anterior to cloacal lip, different length of the right spicule, and short gubernaculum; it differs in females by the distances of vulva and anus from the posterior end respectively. We found the new species in a different infection site from that of the type species. Thus, this is the second species of Pneumoatractis described in Po. unifilis and the first in Po. expansa.


Assuntos
Ascaridídios , Tartarugas , Feminino , Masculino , Animais , Brasil/epidemiologia , Água Doce , Rios
12.
Parasitol Res ; 122(6): 1261-1269, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37014474

RESUMO

The genus Spirocerca includes nematodes that parasitize the stomach and the oesophagus of carnivores, chiefly canids. Herein, we provide new data about the morphological, histopathological, and molecular characterization of Spirocerca sp. in Andean foxes (Lycalopex culpaeus) in Chile. Intact immature worms, identified as Spirocerca sp., were recovered in the lumen of the stomach from two foxes. Histologically, worms morphologically consistent with spirurid nematodes were present within the wall of the stomach and surrounded by nodular areas of inflammation with central necrotic debris. Molecular analysis of the cox1 gene yielded 19 sequences and 5 nucleotide sequence types with 99.95 to 99.98% similarity, being shared between both foxes. Nucleotide similarity ranged from 93.1 (with genotype 2 of S. lupi and S. vulpis) to 95.8% (with genotype 1 of S. lupi), a higher similarity than noted from sequences of S. lupi from an Andean fox from Peru (91.0 to 93.3%). However, the Poisson Tree Processes for species delineation did not support the existence of a new species Spirocerca. Phylogenetic and nucleotide analyses suggest that these specimens belong to a new variant or genotype of S. lupi or to a cryptic species. Whether the presence of the worms in the stomach has to do with genotypic differences in parasites or host or some combination is uncertain. Spirocerca lupi has never been found in Chilean dogs and must be investigated.


Assuntos
Doenças do Cão , Infecções por Spirurida , Thelazioidea , Cães , Animais , Raposas/parasitologia , Chile/epidemiologia , Filogenia , Infecções por Spirurida/epidemiologia , Infecções por Spirurida/veterinária , Infecções por Spirurida/parasitologia , Estômago/parasitologia , Thelazioidea/genética , Nucleotídeos , Doenças do Cão/parasitologia
13.
Vet Parasitol Reg Stud Reports ; 39: 100842, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36878627

RESUMO

Populations of the coati, Nasua nasua, like the populations of other wild animals, are regulated by several biotic or abiotic factors. For example, parasites act as a biotic factor affecting the dynamics and density of coati populations. The parasitic nematodes of coatis include Dirofilaria species, such as Dirofilaria immitis, Dirofilaria repens, and Dirofilaria incrassata. Considering that there are few records on parasitism by D. incrassata, including information on the life cycle or location in the host body, this study aimed to investigate the infection of N. nasua by D. incrassata in midwestern Brazil. Thus, two coatis (males and adults) from the Cerrado of Goiás, which died (cause unknown) at the Wild Animal Screening Center/IBAMA in the municipality of Goiânia, Goiás, Midwestern of Brazil, were dissected and all helminths found were collected, identified following specific keys and quantified. A total of 85 specimens of D. incrassata were collected, with a mean parasitic intensity of 42.5 and a parasitic amplitude ranging from 40 to 45, measuring 41-93 mm in length and 0.23-0.45 mm in width. All helminths were adults and were distributed in the superficial and deep fascia (at different levels) from the neck to the hind limb. Most helminths were tangled, with some encased in a connective tissue film. Most reported human heartworm cases refer to subcutaneous or ocular heartworm infection, mainly caused by D. repens, although other species of heartworm may be associated. D. incrassata was not reported as zoonotic agent, diferently of other Dirofilaria species associated with wild animals and with zoonotic potential in the Americas. This study reiterates N. nasua as the definitive host for D. incrassata and the subcutaneous tissue as the site of choice for this helminth in the adult form. In addition, it reports new body regions where the parasite occurs. This study is the first to document the occurrence of D. incrassata infestation in the State of Goiás, Brazil.


Assuntos
Dirofilaria immitis , Dirofilaria repens , Animais , Humanos , Masculino , Animais Selvagens , Brasil/epidemiologia , Membro Posterior
14.
Pathogens ; 12(2)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36839447

RESUMO

Wild boars (Sus scrofa) are a significant invasive species in Brazil. We evaluated the helminth diversity of 96 wild boars in São Paulo state. Helminth infection descriptors were calculated, the species were identified and their 18S, 28S rDNA and internal transcribed spacer (ITS) regions were amplified for phylogenetic analyses. Ascarops strongylina, Strongyloides ransomi, Globocephalus urosubulatus, Oesophagostomum dentatum, Trichuris suis, Metastrongylus salmi, Metastrongylus pudendotecus, Ascaris suum and Stephanurus dentatus and Macracanthorhynchus hirudinaceus were identified. Globocephalus urosubulatus had the highest prevalence and mean abundance, and most animals had mixed infections with three parasite species. There was no association between parasite intensity and prevalence and host sex and body condition index (p > 0.05). Novel DNA sequences were obtained from G. urosubulatus, A. strongylina, and S. dentatus. This is the first study on the helmint diversity of non-captive wild boars in Brazil, and the first report of the occurrence of M. hirudinaceus, G. urosubulatus and S. dentatus in Brazilian wild boars. Non-captive wild boars of São Paulo State did not act as capture hosts for native helminth species but maintained their typical parasites, common to domestic pigs. They may act as parasite dispersers for low-tech subsistence pig farming and for native Tayassuidae.

15.
J Helminthol ; 97: e9, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36648225

RESUMO

A new species of Ancyracanthus, parasite of the electric eel Electrophorus varii, in the Brazilian Amazon, is described based on morphological and molecular characterization. Ancyracanthus electrophori n. sp. differs from the two congeners namely, Ancyracanthus pinnatifidus and Ancyracanthus schubarti, based on the structure of cephalic appendages, number and arrangement of caudal papillae in males, vulva very close to anus in females, eggs with smoothly mamillated shell, host taxon and geographical origin. Moreover, the new species is the first in the genus to be described with thorny cuticular rings and to be observed with the use of scanning electron microscopy (SEM). The morphology of A. pinnatifidus and A. schubarti is still poorly-known and should be revised in details; however, the separation between them and the new species was clear. Genetic characterization based on 28S rDNA and cytochrome c oxidase subunit I (cox1) mtDNA partial sequences, performed for the first time in Acyracanthus, along with phylogenetic reconstructions using both genetic markers, placed Ancyracanthus electrophori n. sp. in a suggestive basal position within Gnathostomatidae. Phylogenetic reconstructions using cox1 sequences also suggested lack of monophyly in the genera Gnathostoma and Spiroxys and, consequently, in the subfamilies Gnathostominae and Spiroxyinae. However, such results are preliminary. With the first genetic characterization and observations using SEM in Ancyracanthus, resulting in the discovery of a new species and in the expansion of the geographical occurrence of the genus to Amazonian fish, an important step towards a better understanding of these nematodes has been taken.


Assuntos
Gimnotiformes , Nematoides , Parasitos , Espirurídios , Feminino , Masculino , Animais , Electrophorus , Filogenia , Brasil
16.
Parasitol Res ; 122(2): 557-569, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36526926

RESUMO

Cucullanus pinnai has been divided in two subspecies (C. pinnai pinnai and C. pinnai pterodorasi) based on the morphology of oesophastome. While C. pinnai pinnai apparently shows low host specificity and broad geographic occurrence, with certain morphological variations, C. pinnai pterodorasi was reported once, parasitizing Pterodoras granulosus. We used an integrative taxonomic approach to evaluate whether or not populations of C. pinnai pinnai from Trychomycterus spegazzinii (Escoipe River, Argentina) and Pimelodus fur (Miranda River, Brazil), and of C. pinnai pterodorasi from Pterodoras granulosus (Miranda River, Brazil) are conspecific. Parasites were observed using light microscopy and genetically characterized based on partial sequences of the 18S and 28S rDNA, ITS1-5.8S-ITS2, and COI mtDNA. Phylogenies were reconstructed and the Generalized Mixed Yule Coalescent (GMYC), Poisson Tree Process (bPTP), and Automatic Barcode Gap Discovery (ABGD) were used for species delimitation purposes. The present samples formed well-supported monophyletic assemblages, corroborating in part the results of morphological analyses; however, they grouped according to geographic origin. Species delimitation suggested conspecificity of C. pinnai pinnai with C. pinnai pterodorasi from Brazil; consequently, the morphology of oesophastome may be an intraspecific variation. Results also indicated that C. pinnai may represent a species complex as samples from Argentina were suggestive of an independent specific entity. However, definitive affirmations are premature, since there is no autapomorphy for separating C. pinnai from Brazil and Argentina and sampling was limited to three host species from two river basins. The phylogenetic reconstructions also confirmed the artificiality of some genera within Cucullanidae.


Assuntos
Ascaridoidea , Peixes-Gato , Animais , Filogenia , Código de Barras de DNA Taxonômico , Peixes-Gato/parasitologia , Microscopia Eletrônica de Varredura
17.
Parasitol Int ; 93: 102714, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36462634

RESUMO

About 20 valid species of the genus Rhabdias are known in the Neotropical region. The present study aimed to describe two new species of Rhabdias parasitizing the lungs of Leptodactylus macrosternum and Leptodactylus podicipinus from Brazil. Distinctive characteristics between these species are numerous and based on body size, size of the buccal capsule, shape and size of the oesophagus, and position of the vulva. Molecular data based on ribosomal genes 28S and ITS region and mitochondrial COI of the two species are presented. Molecular analysis and comparison of the partial mitochondrial COI sequence of Rhabdias matogrossensis n. sp. and Rhabdias guaianensis n. sp. revealed a genetic divergence between these new species and the sequences of Rhabdias spp. previously deposited in GenBank. In the phylogenetic analysis, R. matogrossensis n. sp. was grouped with R. breviensis species complex, and R. guaianensis n. sp. was grouped as a sister group of R. cf. stenochepala. This study contributes to improving the diversity of known species of Rhabdias described in Brazilian anurans.


Assuntos
Anuros , Rhabdiasoidea , Animais , Feminino , Filogenia , Brasil/epidemiologia , Pulmão
18.
Parasitology ; 150(2): 172-183, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36444644

RESUMO

Helminth species of Neotropical bats are poorly known. In Mexico, few studies have been conducted on helminths of bats, especially in regions such as the Yucatan Peninsula where Chiroptera is the mammalian order with the greatest number of species. In this study, we characterized morphologically and molecularly the helminth species of bats and explored their infection levels and parasite­host interactions in the Yucatan Peninsula, Mexico. One hundred and sixty-three bats (representing 21 species) were captured between 2017 and 2022 in 15 sites throughout the Yucatan Peninsula. Conventional morphological techniques and molecular tools were used with the 28S gene to identify the collected helminths. Host­parasite network analyses were carried out to explore interactions by focusing on the level of host species. Helminths were found in 44 (26.9%) bats of 12 species. Twenty helminth taxa were recorded (7 trematodes, 3 cestodes and 10 nematodes), including 4 new host records for the Americas. Prevalence and mean intensity of infection values ranged from 7.1 to 100% and from 1 to 56, respectively. Molecular analyses confirmed the identity of some helminths at species and genus levels; however, some sequences did not correspond to any of the species available on GenBank. The parasite­host network suggests that most of the helminths recorded in bats were host-specific. The highest helminth richness was found in insectivorous bats. This study increases our knowledge of helminths parasitizing Neotropical bats, adding new records and nucleotide sequences.


Assuntos
Quirópteros , Helmintíase Animal , Helmintos , Nematoides , Parasitos , Animais , Quirópteros/parasitologia , México/epidemiologia , Helmintos/genética , Interações Hospedeiro-Parasita , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia
19.
Braz. j. biol ; 832023.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469051

RESUMO

Abstract A new species of nematode parasite of the subfamily Pudicinae (Heligmosomoidea: Heligmonellidae) is described from the small intestine of Proechimys simonsi (Rodentia: Echimyidae) from the locality of Nova Cintra in the municpality of Rodrigues Alves, Acre state, Brazil. The genus Pudica includes 15 species parasites of Neotropical rodents of the families Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae, and Myocastoridae. Four species of this nematode were found parasitizing three different species rodents of the genus Proechimys in the Amazon biome. Pudica wandiquei n. sp. can be differentiated from all other Pudica species by the distance between the ends of rays 6 and 8 and the 1-3-1 pattern of the caudal bursa in both lobes.


Resumo Uma nova espécie de nematódeo da subfamília Pudicinae (Heligmosomoidea: Heligmonellidae) é descrito parasitando o intestino delgado de Proechimys simonsi (Rodentia: Echimyidae) em Nova Cintra, município de Rodrigues Alves, Estado do Acre, Brasil. O gênero Pudica inclui 15 espécies parasitas de roedores Neotropicais das famílias: Caviidae, Ctenomyidae, Dasyproctidae, Echimyidae, Erethizontidae e Myocastoridae. Destas, quatro espécies de nematódeos foram encontradas parasitando três diferentes espécies do roedor Proechimys no bioma Amazônia. Pudica wandiquei n. sp. é diferente das outras espécies de Pudica pela distância entre os raios 6 e 8 e pelo tipo da bolsa caudal, que é 1-3-1 em ambos os lados.

20.
Front Vet Sci ; 10: 1325263, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38260198

RESUMO

A new species of nematode parasite of the genus Delicata (Molineidae: Anoplostrongylinae) is described from the small intestine of a road-killed Greater Naked-tailed Armadillo Cabassous tatouay (Cingulata: Chlamyphoridae) on the BR-040 highway in Rio de Janeiro state, Brazil. The genus Delicata includes 13 species of parasitizing armadillos and anteaters distributed in Brazil, Argentina, and Trinidad and Tobago. The present species is distinguished from almost all species of Delicata by the longest length of the body, except for D. khalili and D. appendiculata. However, these can be distinguished from each other by the length of the spicules. The species that closely resembles, Delicata tatouay n. sp. is D. speciosa, but it can be distinguished by a robust branch from rays 2 and 3, rays 4 larger, and rays 8 longer compared to those of the new species. The new species is the only one with a tail, characterized by a terminal spine with rattlesnake tail-like transversal striations.

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