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1.
Braz. j. biol ; 83: e248032, 2023. graf
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1278557

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.


Assuntos
Animais , Parasitos , Trichostrongyloidea , Nematoides , Roedores , Brasil
2.
Braz. j. biol ; 83: e247913, 2023. graf
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1278555

RESUMO

Abstract The aim of this paper was recording the occurrence of the species Lumbriculus variegatus (Müller, 1774) (Oligochaeta, Lumbriculidae) in lotic systems of the State of São Paulo. Specimens were collected in Sapucaí River, located in Campos do Jordão State Park. The mapping of geographical distribution of this species is of interest to public health since L. variegatus may be an intermediate host of Dioctophyme renale (Goeze, 1782) (Nematoda, Dioctophymatidae), a parasite of recognized zoonotic potential. Distribution data serves as a basis for environmental monitoring and evaluation, being essential to map possible cases of the disease (Dioctophimosis) and provide information to health professionals.


Resumo O objetivo deste trabalho foi registrar a ocorrência de Lumbriculus variegatus (Müller, 1774) (Oligochaeta, Lumbriculidae) em um sistema lótico do Estado de São Paulo. Os espécimes foram coletados no rio Sapucaí, localizado no Parque Estadual de Campos do Jordão. O mapeamento da distribuição geográfica desta espécie é de interesse para saúde pública uma vez que L. variegatus pode ser um hospedeiro intermediário de Dioctophyme renale (Goeze, 1782) (Nematoda, Dioctophymatidae), parasito de reconhecido potencial zoonótico. Dados de distribuição servem de base para monitoramento e avaliação ambiental, sendo essenciais para mapear possíveis casos da doença (Dioctofimose) e fornecer informações para profissionais de saúde.


Assuntos
Animais , Oligoquetos , Nematoides , Brasil , Monitoramento Ambiental , Rios
3.
Biol Direct ; 17(1): 13, 2022 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-35659725

RESUMO

BACKGROUND: The evolution of spliceosomal introns has been widely studied among various eukaryotic groups. Researchers nearly reached the consensuses on the pattern and the mechanisms of intron losses and gains across eukaryotes. However, according to previous studies that analyzed a few genes or genomes, Nematoda seems to be an eccentric group. RESULTS: Taking advantage of the recent accumulation of sequenced genomes, we extensively analyzed the intron losses and gains using 104 nematode genomes across all the five Clades of the phylum. Nematodes have a wide range of intron density, from less than one to more than nine per kbp coding sequence. The rates of intron losses and gains exhibit significant heterogeneity both across different nematode lineages and across different evolutionary stages of the same lineage. The frequency of intron losses far exceeds that of intron gains. Five pieces of evidence supporting the model of cDNA-mediated intron loss have been observed in ten Caenorhabditis species, the dominance of the precise intron losses, frequent loss of adjacent introns, high-level expression of the intron-lost genes, preferential losses of short introns, and the preferential losses of introns close to 3'-ends of genes. Like studies in most eukaryotic groups, we cannot find the source sequences for the limited number of intron gains detected in the Caenorhabditis genomes. CONCLUSIONS: These results indicate that nematodes are a typical eukaryotic group rather than an outlier in intron evolution.


Assuntos
Nematoides , Animais , Sequência de Bases , Eucariotos/genética , Evolução Molecular , Íntrons , Nematoides/genética , Filogenia , Spliceossomos/genética
4.
J Helminthol ; 96: e40, 2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35678381

RESUMO

During nematode surveys in natural vegetation in Sierra Mágina, Jaén province, southern Spain, a Longidorus species closely resembling Longidorus carpetanensis was found, but application of integrative taxonomic approaches clearly demonstrated that it is a new species described herein as Longidorus maginicus n. sp. The new species is amphimictic, characterized by a moderately long body (4.2-5.2 mm); lip region anteriorly flattened, slightly separated from the rest of body by a depression, 9.0-11.0 µm wide and 3.5-6.0 µm high; amphidial fovea not lobed; relatively short odontostyle (61.0-70.5 µm); guiding ring located 23.5-27.0 µm from anterior end; vulva located at 42.0%-51.3% of body length; female tail 39.0-61.0 µm long, conoid, dorsally convex with rounded terminus (c' = 1.3-2.1), with two or three pairs of caudal pores; and males common (1:2 ratio males:females), with moderately long spicules (39.0-48.5 µm) and 1 + 6-9 ventromedian supplements and three juvenile developmental stages. According to the polytomous key, codes for the new species are (codes in parentheses are exceptions): A2-B1-C2-D2-E1-F2(3)-G2-H5(4)-I2-J1-K6. The results of molecular analysis of D2-D3 28S, internal transcribed spacer region, partial 18S rDNA, and cytochrome oxidase c subunit 1 (coxI) gene sequences further characterized the new species status, and separated it from L. carpetanensis and other related species.


Assuntos
Nematoides , Animais , Feminino , Masculino , Nematoides/genética , Filogenia , Espanha
5.
Sci Rep ; 12(1): 9725, 2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35697683

RESUMO

Eukaryotes may experience oxygen deprivation under both physiological and pathological conditions. Because oxygen shortage leads to a reduction in cellular energy production, all eukaryotes studied so far conserve energy by suppressing their metabolism. However, the molecular physiology of animals that naturally and repeatedly experience anoxia is underexplored. One such animal is the marine nematode Laxus oneistus. It thrives, invariably coated by its sulfur-oxidizing symbiont Candidatus Thiosymbion oneisti, in anoxic sulfidic or hypoxic sand. Here, transcriptomics and proteomics showed that, whether in anoxia or not, L. oneistus mostly expressed genes involved in ubiquitination, energy generation, oxidative stress response, immune response, development, and translation. Importantly, ubiquitination genes were also highly expressed when the nematode was subjected to anoxic sulfidic conditions, together with genes involved in autophagy, detoxification and ribosome biogenesis. We hypothesize that these degradation pathways were induced to recycle damaged cellular components (mitochondria) and misfolded proteins into nutrients. Remarkably, when L. oneistus was subjected to anoxic sulfidic conditions, lectin and mucin genes were also upregulated, potentially to promote the attachment of its thiotrophic symbiont. Furthermore, the nematode appeared to survive oxygen deprivation by using an alternative electron carrier (rhodoquinone) and acceptor (fumarate), to rewire the electron transfer chain. On the other hand, under hypoxia, genes involved in costly processes (e.g., amino acid biosynthesis, development, feeding, mating) were upregulated, together with the worm's Toll-like innate immunity pathway and several immune effectors (e.g., bactericidal/permeability-increasing proteins, fungicides). In conclusion, we hypothesize that, in anoxic sulfidic sand, L. oneistus upregulates degradation processes, rewires the oxidative phosphorylation and reinforces its coat of bacterial sulfur-oxidizers. In upper sand layers, instead, it appears to produce broad-range antimicrobials and to exploit oxygen for biosynthesis and development.


Assuntos
Chromatiaceae , Nematoides , Animais , Cromadoria , Hipóxia , Nematoides/microbiologia , Oxigênio/metabolismo , Areia , Sulfetos , Enxofre/metabolismo
6.
Nat Commun ; 13(1): 3239, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688815

RESUMO

Many species with separate male and female individuals (termed 'gonochorism' in animals) have sex-linked genome regions. Here, we investigate evolutionary changes when genome regions become completely sex-linked, by analyses of multiple species of flatworms (Platyhelminthes; among which schistosomes recently evolved gonochorism from ancestral hermaphroditism), and roundworms (Nematoda) which have undergone independent translocations of different autosomes. Although neither the evolution of gonochorism nor translocations fusing ancestrally autosomal regions to sex chromosomes causes inevitable loss of recombination, we document that formerly recombining regions show genomic signatures of recombination suppression in both taxa, and become strongly genetically degenerated, with a loss of most genes. Comparisons with hermaphroditic flatworm transcriptomes show masculinisation and some defeminisation in schistosome gonad gene expression. We also find evidence that evolution of sex-linkage in nematodes is accompanied by transcriptional changes and dosage compensation. Our analyses also identify sex-linked genes that could assist future research aimed at controlling some of these important parasites.


Assuntos
Nematoides , Platelmintos , Animais , Compensação de Dosagem (Genética) , Evolução Molecular , Feminino , Masculino , Nematoides/genética , Platelmintos/genética , Cromossomos Sexuais/genética , Transcriptoma/genética
7.
PLoS One ; 17(6): e0269106, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35671263

RESUMO

A survey to collect soil nematodes with potential to control Ceratitis capitata flies was carried out in different locations in Tunisia. Several nematode isolates were recovered, laboratory colonies were established, and their taxonomic identities were determined based on molecular methods. Among all the recovered nematode isolates, two of them, Oscheius tipulae TC2 and OC2, were evaluated for their capacity to control C. capitata flies and for their ability to kill and reproduce on Galleria mellonella larvae. Our results show a great potential of these two isolates as biocontrol agents as they kill C. capitata eggs and pupae and interfere with the metamorphosis of C. capitata larvae. More specifically, TC2 and OC2 nematodes killed 39 and 31% of C. capitata eggs, respectively, impaired the metamorphosis of up to 77% and up to 67% of C. capitata larvae, respectively, and killed up to 66% and up to 58% of C. capitata pupae, respectively. The efficacy of TC2 and OC2 nematodes was particularly high on C. capitata pupae, and significant insect mortalities were observed even at concentrations of 1 and 5 nematodes/pupae, respectively. We also found that TC2 and OC2 nematodes efficiently kill and reproduce in G. mellonella larvae, suggesting that these insects could be used for mass-multiplication of these nematodes. These results reveal the potential of O. tipulae to complement integrated pest management programs against C. capitata flies.


Assuntos
Ceratitis capitata , Nematoides , Rhabditoidea , Animais , Agentes de Controle Biológico , Insetos , Larva , Controle Biológico de Vetores/métodos , Pupa
8.
Trop Anim Health Prod ; 54(4): 208, 2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-35678955

RESUMO

OBJECTIVE: The objective of the study was to assess the effects of water deprivation on the burden of gastrointestinal nematodes in Nguni does. METHODS: A survey was piloted on goat keepers in households where water was scarce (n = 143) and where it was available throughout the year (n = 142). In a controlled experiment, feed intake (ADFI), body condition score (BCS), FAMACHA score, packed cell volume (PCV) and faecal egg counts (FEC) were determined in does deprived of water for 24 and 48 h. RESULTS: There was a significant association between the frequency with which goats drink water and the distance from the water source. From the experiment, an increase in the water deprivation period decreased ADFI, BCS and PCV, and increased FAMACHA scores and faecal egg counts in Nguni goats. The BCS of goats deprived of water for 48 h was 12% lower than the control (p < 0.05). CONCLUSIONS: Reduction in water supply increased gastrointestinal burdens in does, which may compromise their productivity and production efficiency. Depriving goats of water for 24 h had no significant effect on gastrointestinal nematode (GIN) loads. The deprivation period of 48 h increased the GIN burden in does.


Assuntos
Doenças das Cabras , Nematoides , Infecções por Nematoides , Animais , Fezes , Cabras , Infecções por Nematoides/veterinária , Contagem de Ovos de Parasitas/veterinária , Água
9.
Artigo em Inglês | MEDLINE | ID: mdl-35682012

RESUMO

The molecular identification of Cystidicola farionis (a swim bladder nematode of European smelt from the Vistula Lagoon in Poland) was performed. Their prevalence level was determined, and changes in the trehalose synthesis pathway in larvae and adult nematodes were demonstrated. The trehalose level was almost four times higher in adult nematodes than in larvae. In contrast, the activity of both enzymes (trehalose 6-phosphate synthase, TPS and trehalose 6-phosphate phosphatase, TPP) involved in the synthesis of trehalose was higher in larvae than in adults under optimal conditions. The optimum pH for TPS isolated from larvae and adults was pH 7.0. The optimum pH for TPP from larvae and adults was pH 7.0 and pH 8.0, respectively. The optimal temperature was 20 °C, and Mg2+ ions were an activator for trehalose-synthetizing enzymes from both sources. Enzymes isolated from adult nematodes were less susceptible to divalent ion chelator and inorganic phosphate than larval enzymes. The dynamic transformation of trehalose in the nematode developing inside the swim bladder of the smelt appears to be an important metabolic pathway in the nematode survival strategy. These studies are aimed at a better understanding of the issue of the metabolic adaptation of parasites, which, in the future, may indirectly contribute to the elimination of the parasite from aquacultures, which will impact public health.


Assuntos
Nematoides , Osmeriformes , Parasitos , Animais , Osmeriformes/metabolismo , Fosfatos , Trealose/metabolismo , Bexiga Urinária/metabolismo
10.
Trop Anim Health Prod ; 54(4): 198, 2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35666291

RESUMO

Cattle parasitic otitis caused by the nematode Rhabditis spp. is a serious health problem in Brazil, a situation which is confounded by lack of effective control measures. In vitro studies associating biological and chemical control as an alternative method showed promising results. The objective was to evaluate the combined use of Duddingtonia flagrans (AC001), 10% dimethylsulfoxide (DMSO), and 1.9% ivermectin for the in vivo control of Rhabditis spp., in naturally infected Gyr cattle. For this purpose, 48 animals, whose infection in both ears was diagnosed, were randomly assigned to 6 groups: group 1 (ivermectin 1.9%); group 2 (10% DMSO); group 3 (AC001); group 4 (ivermectin 1.9% + 10% DMSO w/v); group 5 (1.9% ivermectin + AC001 w/v); group 6 (10% DMSO + AC001 v/v). The treatments were performed in a single dose, in the right ears, with the left ears remaining untreated, as a control group. There was a significant reduction (p < 0.01) in the number of nematodes in the treated groups in relation to the control, with the following best efficacies: groups 1 and 2, 47% and 52.9%, respectively, 7 days after treatment; groups 3, 4, and 5, 47.8%, 48.6% and 36.7%, respectively, 14 days post-treatment; group 6, 38.4%, 21 days post-treatment. It was concluded that the combination of chemical compounds and D. flagrans in a single application was effective for the in vivo control of Rhabditis spp. in naturally infected cattle.


Assuntos
Doenças dos Bovinos , Duddingtonia , Nematoides , Rhabditoidea , Animais , Ascomicetos , Bovinos , Doenças dos Bovinos/parasitologia , Dimetil Sulfóxido/uso terapêutico , Fezes/parasitologia , Ivermectina/uso terapêutico , Larva , Contagem de Ovos de Parasitas/veterinária , Controle Biológico de Vetores/métodos
11.
Sci Rep ; 12(1): 10156, 2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35710810

RESUMO

The small RNA (sRNA) pathways identified in the model organism Caenorhabditis elegans are not widely conserved across nematodes. For example, the PIWI pathway and PIWI-interacting RNAs (piRNAs) are involved in regulating and silencing transposable elements (TE) in most animals but have been lost in nematodes outside of the C. elegans group (Clade V), and little is known about how nematodes regulate TEs in the absence of the PIWI pathway. Here, we investigated the role of sRNAs in the Clade IV parasitic nematode Strongyloides ratti by comparing two genetically identical adult stages (the parasitic female and free-living female). We identified putative small-interfering RNAs, microRNAs and tRNA-derived sRNA fragments that are differentially expressed between the two adult stages. Two classes of sRNAs were predicted to regulate TE activity including (i) a parasite-associated class of 21-22 nt long sRNAs with a 5' uridine (21-22Us) and a 5' monophosphate, and (ii) 27 nt long sRNAs with a 5' guanine/adenine (27GAs) and a 5' modification. The 21-22Us show striking resemblance to the 21U PIWI-interacting RNAs found in C. elegans, including an AT rich upstream sequence, overlapping loci and physical clustering in the genome. Overall, we have shown that an alternative class of sRNAs compensate for the loss of piRNAs and regulate TE activity in nematodes outside of Clade V.


Assuntos
MicroRNAs , Nematoides , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Elementos de DNA Transponíveis/genética , Feminino , MicroRNAs/genética , Nematoides/genética , Nematoides/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo
12.
Mar Pollut Bull ; 180: 113814, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35679809

RESUMO

Free-living nematodes were investigated in three Mediterranean commercial ports (Ancona and Trieste, Italy; Koper, Slovenia) in terms of abundance, diversity and functionality. Results indicated that r-strategist genera were dominant in all ports and that a more diverse assemblage characterized Trieste, despite the high contamination levels, suggesting a potential adaptation to long-standing contamination. The main environmental factor that shaped the assemblage in all ports were Total Polycyclic Aromatic Hydrocarbons, while Total Organic Carbon and the grain-size were less relevant. A co-occurrence analysis was applied for identifying which genera cohesively respond to site-specific environmental conditions in order to recalibrate and implement the sets of bioindicator genera in relation to their different opportunistic behaviour. Finally, we provided some suggestions for a proper application of the nematode indices (Maturity Index, Index of Trophic Diversity, Shannon diversity) in order to encourage the use of free-living nematodes for the environmental quality assessment of commercial ports.


Assuntos
Nematoides , Hidrocarbonetos Policíclicos Aromáticos , Animais , Monitoramento Ambiental , Itália , Mar Mediterrâneo , Hidrocarbonetos Policíclicos Aromáticos/análise , Eslovênia
13.
Curr Biol ; 32(9): R428-R430, 2022 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-35537396

RESUMO

A new study finds that a bacterium from the microbiome of the nematode Pristionchus pacificus can promote rapid growth, increased body size, and increased fecundity by inducing neuronal expression of TGF-ß ligands. This is an intriguing example of how the microbiota induces systemic effects in the host by stimulating neuroendocrine signaling.


Assuntos
Microbiota , Nematoides , Animais , Bactérias , Nematoides/fisiologia
14.
Emerg Infect Dis ; 28(6): 1163-1169, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35608603

RESUMO

Neural angiostrongyliasis is an emerging zoonosis caused by the rat lungworm, Angiostrongylus cantonensis. In humans, infection with this nematode often results in eosinophilic meningitis and other severe disorders of the central nervous system. Europe was deemed a nonendemic region until 2018, when A. cantonensis worms were detected on the Mediterranean island of Mallorca, Spain, a tourism hotspot. Since that time, a sentinel surveillance system and a molecular approach have been used to follow the invasion path of the rat lungworm on the island. A. cantonensis worms have been found in animals from 8 locations on the island over 3 consecutive years. Our preliminary results show a recognizable pattern of clinical signs in infected hedgehogs and a single mitochondrial haplotype circulating in Mallorca. We present strong evidence confirming that the rat lungworm has successfully established and colonized an island in Europe and discuss observations and possible strategies for its early detection across continental Europe.


Assuntos
Angiostrongylus cantonensis , Meningite , Nematoides , Infecções por Strongylida , Angiostrongylus cantonensis/genética , Animais , Ratos , Espanha/epidemiologia , Infecções por Strongylida/epidemiologia , Infecções por Strongylida/veterinária
15.
J Gen Virol ; 103(5)2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35550022

RESUMO

Reverse-transcribing retroviruses exist as horizontally transmitted infectious agents or vertically transmitted endogenous retroviruses (ERVs) resident in eukaryotic genomes, and they are phylogenetically related to the long terminal repeat (LTR) class of retrotransposons. ERVs and retrotransposons are often distinguished only by the presence or absence of a gene encoding the envelope glycoprotein (env). Endogenous elements of the virus family Metaviridae include the insect-restricted Errantivirus genus of ERVs, for which some members possess env, and the pan-eukaryotic Metavirus genus that lacks an envelope glycoprotein gene. Here we report a novel Nematoda endogenous retrovirus (NERV) clade with core retroviral genes arranged uniquely as a continuous gag-env-pro-pol ORF. Reverse transcriptase sequences were phylogenetically related to metaviruses, but envelope glycoprotein sequences resembled those of the Nyamiviridae and Chrysoviridae RNA virus families, suggesting env gene capture during host cell infection by an RNA virus. NERVs were monophyletic, restricted to the nematode subclass Chromadoria, and included additional ORFs for a small hypothetical protein or a large Upf1-like RNA-dependent AAA-ATPase/helicase indicative of viral transduction of a host gene. Provirus LTR identity, low copy number, ORF integrity and segregation of three loci in Meloidogyne incognita, taken together with detection of NERV transcriptional activity, support potential infectivity of NERVs, along with their recent emergence and integration. Altogether, NERVs constitute a new and distinct Metaviridae lineage demonstrating retroviral evolution through sequential heterologous gene capture events.


Assuntos
Retrovirus Endógenos , Nematoides , Animais , Retrovirus Endógenos/genética , Glicoproteínas/genética , Retroelementos , Sequências Repetidas Terminais
16.
Trop Anim Health Prod ; 54(3): 179, 2022 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-35511381

RESUMO

We aimed to evaluate a Brazilian commercial formulation of the fungus Duddingtonia flagrans (Bioverm®) for controlling gastrointestinal nematodes in sheep kept on native pasture in the Caatinga biome, in the semiarid region of Brazil. Twenty ewes, aged between 12 and 18 months, were divided into two groups. In the treated group, each animal received 1 g of the Bioverm® product for each 10 kg of live weight, daily, together with commercial feed, for 6 months. In the control group, the animals received feed without Bioverm®. Each group remained throughout the experiment in a 1.2-ha paddock. Monthly counts of eggs per gram (EPG) of feces, fecal cultures, packed cell volume (PCV), weight measurements, and collection of leaf mass from the pasture were performed. There was greater reduction in EPG, greater weight gain, and less infestation by infective larvae in the paddock of the Bioverm® group, compared with the control group (p < 0.05). There was no significant difference (p ≥ 0.05) in the mean PCV percentage between the Bioverm® and control groups. In coprocultures, Haemonchus sp. was the most prevalent helminth. Bioverm® (D. flagrans) was efficient for biological control of sheep gastrointestinal nematodes in the semiarid region of Brazil.


Assuntos
Nematoides , Doenças dos Ovinos , Animais , Ascomicetos , Brasil/epidemiologia , Fezes , Feminino , Larva , Óvulo , Contagem de Ovos de Parasitas/veterinária , Controle Biológico de Vetores , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/prevenção & controle
17.
PLoS One ; 17(5): e0268691, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35622785

RESUMO

Studies conducted in the same seas or even study sites nearby each other, showed very different community structure, implying the patchiness of free-living marine nematodes which may be related to the sedimentary environment such as sediment type and food availability of the study area. This study was motivated by the concerns about the impacts of high level of anthropogenic activities on Chaojing Park (gazetted as Wanghaixiang's Chao-Jing Bay Resource Conservation Area (WCJBRA) in 2016). The present study provides baseline knowledge of free-living marine nematode community structure in WCJBRA and identify potential marine nematodes as bioindicators to indicate possible impacts of the anthropogenic activities to the Chaojing Park. A total of 15 stations were selected in the subtidal zones of WCJBRA and its adjacent area. Marine nematode sample collection was carried out on the 13th and 14th of September 2019 using SCUBA diving technique. Results showed positive correlation between nematode density and medium sand (500µm-1.0mm). Presence of certain species such as Daptonema sp., Pomponema sp. and Innocuonema sp. indicates presence of disturbances in S12 and S13. Several species also showed potential to be introduced as indicator for healthy environment subjected to further studies on nematode-pollutants relationship, particularly on autecology as per se. Higher species diversity, H' index of S1-S8 and S11 was categorised as Good Condition; followed by station with moderate species diversity index (S9, S10, S14 -Moderate Condition) zone; and lastly S12, S13 and S15 (Poor Condition).


Assuntos
Poluentes Ambientais , Nematoides , Animais , Baías , Sedimentos Geológicos/química , Taiwan
18.
J Helminthol ; 96: e33, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35514266

RESUMO

We report the first mermithid nematode found to be parasitic in a marine tanaidacean crustacean. Ten host tanaidaceans were collected from a depth of 52 m in Otsuchi Bay, Iwate, Japan, north-western Pacific, and identified as a species in the tanaidid genus Zeuxo Templeton, 1840. Nematodes occurred in the host's body cavity; in one case, at least two individuals inhabited a single host. We provide a brief description and illustrations of the morphology of the nematode. In a phylogenetic reconstruction based on the 18S ribosomal RNA gene, the nematode nested in a clade otherwise containing mermithids from terrestrial or freshwater hosts, showing an expansion in host utilization in Mermithidae Braun, 1883 from terrestrial/freshwater hosts to a marine organism.


Assuntos
Helmintos , Mermithoidea , Nematoides , Animais , Organismos Aquáticos , Água Doce , Humanos , Mermithoidea/anatomia & histologia , Mermithoidea/genética , Filogenia
19.
Front Immunol ; 13: 878783, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35515005

RESUMO

Nematodes and bacteria are prevalent in soil ecosystems, and some have evolved symbiotic relationships. In some cases, symbionts carry out highly specialized functions: a prime example being entomopathogenic nematodes (EPNs), which vector bacteria (Xenorhabdus or Photorhabdus) into insect hosts, killing them to provide a food source for the nematodes. It is thought that the commercially available malacopathogenic (kills slugs and snails) biocontrol nematode Phasmarhabditis hermaphrodita vectors a bacterium (Moraxella osloensis) into slugs to kill them. To investigate this further we used a metagenomic approach to profile the bacteria present in the commercial strain of P. hermaphrodita, a wild strain of P. hermaphrodita and two other Phasmarhabditis species (P. californica and P. neopapillosa), after they had killed their slug host (Deroceras invadens). We show that these nematodes do not exclusively associate with one bacterium but a range of species, with members of the phyla Pseudomonadota, Bacillota, Actinobacteriota and Bacteroidota the most prevalent. The commercial strain of P. hermaphrodita had the least diverse bacterial community. Furthermore, we found that the bacterium P. hermaphrodita has been cultured on for 25 years is not the expected species M. osloensis but is Psychrobacter spp. and the only strain of the Phasmarhabditis species to associate with Psychrobacter spp. was the commercial strain of P. hermaphrodita. In summary, we found no evidence to show that P. hermaphrodita rely exclusively on one bacterium to cause host mortality but found variable and diverse bacterial communities associated with these nematodes in their slug hosts.


Assuntos
Microbiota , Nematoides , Rhabditoidea , Animais , Rhabditoidea/microbiologia , Caramujos , Solo
20.
Trop Biomed ; 39(1): 135-143, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35507936

RESUMO

Soil-transmitted helminth (STH) infections, mainly caused by Ascaris lumbricoides, Trichuris trichiura, and hookworms, are among the most common intestinal parasites that infect humans. The infections are widely distributed throughout tropical and subtropical countries, including Malaysia, particularly in underprivileged communities. Microscopic and culture techniques have been used as a gold standard for diagnostic techniques. However, these methods yield low sensitivity and specificity, laborious and time-consuming. Therefore, simple, rapid, and accurate alternative methods are needed for the simultaneous detection of STH infections. Although advanced technologies such as real-time multiplex PCR have been established, the use of this technique as a routine diagnostic is limited due to the high cost of the instrument. Therefore, a single-round multiplex conventional PCR assay for rapid detection of four STH species in the fecal sample was developed in this study. To perform the single-round multiplex PCR, each pair of species-specific primers was selected from target genes, including Ancylostoma duodenale (Internal Transcribed Spacer 2; accession No. AJ001594; 156 base pair), Necator americanus (ITS 2; accession No. AJ001599; 225 base pair), Ascaris lumbricoides (Internal Transcribed Spacer 1; accession No. AJ000895; 334 base pair) and Trichuris triciura (partial ITS 1, 5.8s rRNA and partial ITS 2; accession No. AM992981; 518 base pair). The results showed that the newly designed primers could detect the DNA of STH at low concentrations (0.001 ng/ µl) with no cross-amplification with other species. This assay enables the differentiation of single infections as well as mixed infections. It could be used as an alternative and is a convenient method for the detection of STHs, especially for the differentiation of N. americanus and A. duodenale.


Assuntos
Helmintíase , Nematoides , Animais , Ascaris lumbricoides/genética , Primers do DNA , Fezes/parasitologia , Helmintíase/diagnóstico , Humanos , Reação em Cadeia da Polimerase Multiplex/métodos , Solo/parasitologia , Trichuris/genética
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