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1.
Sci Rep ; 14(1): 15456, 2024 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965317

RESUMO

Medicinal plant microbiomes undergo selection due to secondary metabolite presence. Resident endophytic/epiphytic microorganisms directly influence plant's bioactive compound synthesis. Hypothesizing low microbial diversity in Serjania erecta leaves, we assessed leaf colonization by epiphytic and endophytic fungi. Given its traditional medicinal importance, we estimated diversity in the endophytic fungal microbiome. Analyses included scanning electron microscopy (SEM), isolation of cultivable species, and metagenomics. Epiphytic fungi interacted with S. erecta leaf tissues, horizontally transmitted via stomata/trichome bases, expressing traits for nematode trapping. Cultivable endophytic fungi, known for phytopathogenic habits, didn't induce dysbiosis symptoms. This study confirms low leaf microbiome diversity in S. erecta, with a tendency towards more fungal species, likely due to antibacterial secondary metabolite selection. The classification of Halicephalobus sp. sequence corroborated the presence of nematode eggs on the epidermal surface of S. erecta by SEM. In addition, we confirmed the presence of methanogenic archaea and a considerable number of methanotrophs of the genus Methylobacterium. The metagenomic study of endophytic fungi highlighted plant growth-promoting yeasts, mainly Malassezia, Leucosporidium, Meyerozyma, and Hannaella. Studying endophytic fungi and S. erecta microbiomes can elucidate their impact on beneficial bioactive compound production, on the other hand, it is possible that the bioactive compounds produced by this plant can recruit specific microorganisms, impacting the biological system.


Assuntos
Fungos , Microbiota , Nematoides , Folhas de Planta , Folhas de Planta/microbiologia , Folhas de Planta/parasitologia , Animais , Nematoides/microbiologia , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Endófitos/genética , Endófitos/isolamento & purificação , Leveduras/classificação , Leveduras/isolamento & purificação , Leveduras/genética , Metagenômica/métodos , Biodiversidade
2.
Nat Commun ; 15(1): 5529, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38956039

RESUMO

Left unchecked, plant-parasitic nematodes have the potential to devastate crops globally. Highly effective but non-selective nematicides are justifiably being phased-out, leaving farmers with limited options for managing nematode infestation. Here, we report our discovery of a 1,3,4-oxadiazole thioether scaffold called Cyprocide that selectively kills nematodes including diverse species of plant-parasitic nematodes. Cyprocide is bioactivated into a lethal reactive electrophilic metabolite by specific nematode cytochrome P450 enzymes. Cyprocide fails to kill organisms beyond nematodes, suggesting that the targeted lethality of this pro-nematicide derives from P450 substrate selectivity. Our findings demonstrate that Cyprocide is a selective nematicidal scaffold with broad-spectrum activity that holds the potential to help safeguard our global food supply.


Assuntos
Antinematódeos , Sistema Enzimático do Citocromo P-450 , Nematoides , Animais , Sistema Enzimático do Citocromo P-450/metabolismo , Nematoides/efeitos dos fármacos , Antinematódeos/farmacologia , Sulfetos/farmacologia , Sulfetos/química
3.
Commun Biol ; 7(1): 850, 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38992096

RESUMO

Plant pathogens cause billions of dollars of crop loss every year and are a major threat to global food security. Identifying and characterizing pathogens effectors is crucial towards their improved control. Because of their poor sequence conservation, effector identification is challenging, and current methods generate too many candidates without indication for prioritizing experimental studies. In most phyla, effectors contain specific sequence motifs which influence their localization and targets in the plant. Therefore, there is an urgent need to develop bioinformatics tools tailored for pathogen effectors. To circumvent these limitations, we have developed MOnSTER a specific tool that identifies clusters of motifs of protein sequences (CLUMPs). MOnSTER can be fed with motifs identified by de novo tools or from databases such as Pfam and InterProScan. The advantage of MOnSTER is the reduction of motif redundancy by clustering them and associating a score. This score encompasses the physicochemical properties of AAs and the motif occurrences. We built up our method to identify discriminant CLUMPs in oomycetes effectors. Consequently, we applied MOnSTER on plant parasitic nematodes and identified six CLUMPs in about 60% of the known nematode candidate parasitism proteins. Furthermore, we found co-occurrences of CLUMPs with protein domains important for invasion and pathogenicity. The potentiality of this tool goes beyond the effector characterization and can be used to easily cluster motifs and calculate the CLUMP-score on any set of protein sequences.


Assuntos
Motivos de Aminoácidos , Biologia Computacional , Animais , Biologia Computacional/métodos , Doenças das Plantas/parasitologia , Doenças das Plantas/microbiologia , Plantas/parasitologia , Oomicetos/genética , Oomicetos/metabolismo , Nematoides/genética , Proteínas de Helminto/genética , Proteínas de Helminto/metabolismo , Proteínas de Helminto/química , Software
4.
Parasitol Res ; 123(7): 267, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38990228

RESUMO

Exsheathment is crucial in the transition from free-living to parasitic phase for most strongyle nematode species. A greater understanding of this process could help in developing new parasitic control methods. This study aimed to identify commonalities in response to exsheathment triggers (heat acclimation, CO2 and pH) in a wide range of species (Haemonchus contortus, Trichostrongylus spp., Cooperia spp., Oesophagostomum spp., Chabertia ovina, and members of the subfamily Ostertagiinae) from sheep, cattle and farmed deer. The initial expectation of similarity in pH requirements amongst species residing within the same organ was not supported, with unexpected pH preferences for exsheathment of Trichostrongylus axei, Trichostrongylus vitrinus, Trichostrongylus colubriformis and Cooperia oncophora. We also found differences between species in their response to temperature acclimation, with higher exsheathment in response to heat shock observed for H. contortus, Ostertagia ostertagi, T. axei, T. vitrinus and Oesophagostomum sikae. Furthermore, some species showed poor exsheathment under all experimental conditions, such as Cooperia curticei and the large intestinal nematodes C. ovina and Oesophagostomum venulosum. Interestingly, there were some significant differences in response depending on the host from which the parasites were derived. The host species significantly impacted on the exsheathment response for H. contortus, Teladorsagia circumcincta, T. vitrinus and T. colubriformis. Overall, the data showed variability between nematode species in their response to these in vitro exsheathment triggers, highlighting the complexity of finding a common set of conditions for all species in order to develop a control method based on triggering the exsheathment process prematurely.


Assuntos
Cervos , Infecções por Nematoides , Doenças dos Ovinos , Animais , Cervos/parasitologia , Bovinos , Ovinos/parasitologia , Doenças dos Ovinos/parasitologia , Infecções por Nematoides/parasitologia , Infecções por Nematoides/veterinária , Concentração de Íons de Hidrogênio , Nematoides/fisiologia , Nematoides/classificação , Doenças dos Bovinos/parasitologia , Dióxido de Carbono , Enteropatias Parasitárias/veterinária , Enteropatias Parasitárias/parasitologia , Temperatura Alta
5.
PLoS One ; 19(6): e0301554, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38861496

RESUMO

In Sudan, resistance to benzimidazoles has been reported recently in cattle and goats from South Darfur. Herein, ivermectin efficacy against gastrointestinal nematodes (GINs) was evaluated in sheep and goats in three study areas in South Darfur. The faecal egg count reduction test (FECRT) was used to evaluate the efficacy of ivermectin in sheep and goats naturally infected with GINs in the region of Bulbul (goats: n = 106), Kass (goats: n = 40) and Nyala (Domaia (sheep: n = 47, goats: n = 77) and the University farm (goats: n = 52)), using different treatment plans, and the efficacy was evaluated 12 days after treatment. Ivermectin efficacy was also evaluated in goats experimentally infected using local Haemonchus contortus isolates from Kass and Nyala. Nematodes surviving ivermectin treatment in goats in Bulbul and Nyala were harvested and larvae used to infect worm-free male sheep (n = 6, ≤6 months old). Infected sheep were dosed subcutaneously with ivermectin every eight days with increasing doses from 0.2 mg/kg to 1.6 mg/kg bodyweight (bw). Reduced ivermectin efficacy was identified in sheep and goats in the four study locations. Using a paired statistic, the efficacy of a therapeutic dose in sheep was 75.6% (90% upper credible limit (UCrL): 77.5%), while twice the recommended dose led to a reduction of 92.6% (90% UCrL: 93.3%). In goats, the FECRs of a therapeutic dose were 72.9-95.3% (90% UCrL range: 73.6-95.7%) in Bulbul, Nyala Domaia, Nyala University farm and Kass. Twice the dose recommended for goats in Bulbul revealed a 90% UCrL of 87.6%. All post-treatment faecal cultures contained only Haemonchus spp. larvae. The experimental infection trials in sheep and goats supported our findings from field trials and calculated upper 90% CrL of below 98.9%. For the first time highly ivermectin resistant H. contortus populations have been identified in sheep and goats in Sudan, and resistance was experimentally confirmed.


Assuntos
Resistência a Medicamentos , Doenças das Cabras , Cabras , Ivermectina , Infecções por Nematoides , Doenças dos Ovinos , Animais , Cabras/parasitologia , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Ovinos/parasitologia , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/parasitologia , Sudão , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/veterinária , Infecções por Nematoides/parasitologia , Fezes/parasitologia , Masculino , Contagem de Ovos de Parasitas/veterinária , Nematoides/efeitos dos fármacos , Anti-Helmínticos/uso terapêutico , Anti-Helmínticos/farmacologia , Haemonchus/efeitos dos fármacos
6.
Toxins (Basel) ; 16(6)2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38922168

RESUMO

Claviceptaceous endophytic fungi in the genus Epichloë mostly form a symbiotic relationship with cool-season grasses. Epichloë spp. are capable of producing bioactive alkaloids such as peramines, lolines, ergot alkaloids, and indole-diterpenes, which protect the host plant from herbivory by animals, insects, and nematodes. The host also benefits from enhanced tolerance to abiotic stresses, such as salt, drought, waterlogging, cold, heavy metals, and low nitrogen stress. The bioactive alkaloids produced can have both direct and indirect effects towards plant parasitic nematodes. Direct interaction with nematodes' motile stages can cause paralysis (nematostatic effect) or death (nematicidal effect). Indirectly, the metabolites may induce host immunity which inhibits feeding and subsequent nematode development. This review highlights the different mechanisms through which this interaction and the metabolites produced have been explored in the suppression of plant parasitic nematodes and also how the specific interactions between different grass genotypes and endophyte strains result in variable suppression of different nematode species. An understanding of the different grass-endophyte interactions and their successes and failures in suppressing various nematode species is essential to enable the proper selection of grass-endophyte combinations to identify the alkaloids produced, concentrations required, and determine which nematodes are sensitive to which specific alkaloids.


Assuntos
Alcaloides , Endófitos , Nematoides , Poaceae , Animais , Alcaloides/farmacologia , Endófitos/metabolismo , Poaceae/parasitologia , Nematoides/efeitos dos fármacos , Epichloe/metabolismo , Doenças das Plantas/parasitologia , Doenças das Plantas/microbiologia
7.
Genes (Basel) ; 15(6)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38927648

RESUMO

Infections with gastrointestinal nematodes (GINs) reduce the economic efficiency of sheep operations and compromise animal welfare. Understanding the host's response to GIN infection can help producers identify animals that are naturally resistant to infection. The objective of this study was to characterize the hepatic transcriptome of sheep that had been naturally exposed to GIN parasites. The hepatic transcriptome was studied using RNA-Sequencing technology in animals characterized as high (n = 5) or medium (n = 6) based on their innate immune acute-phase (AP) response phenotype compared with uninfected controls (n = 4), and with biased antibody-mediated (AbMR, n = 5) or cell-mediated (CMR, n = 5) adaptive immune responsiveness compared to uninfected controls (n = 3). Following the assessment of sheep selected for innate responses, 0, 136, and 167 genes were differentially expressed (DE) between high- and medium-responding animals, high-responding and uninfected control animals, and medium-responding and uninfected control animals, respectively (false discovery rate (FDR) < 0.05, and fold change |FC| > 2). When adaptive immune responses were assessed, 0, 53, and 57 genes were DE between antibody- and cell-biased animals, antibody-biased and uninfected control animals, and cell-biased and uninfected control animals, respectively (FDR < 0.05, |FC| > 2). Functional analyses identified enriched gene ontology (GO) terms and metabolic pathways related to the innate immune response and energy metabolism. Six functional candidate genes were identified for further functional and validation studies to better understand the underlying biological mechanisms of host responses to GINs. These, in turn, can potentially help improve decision making and management practices to increase the overall host immune response to GIN infection.


Assuntos
Imunidade Inata , Fígado , Infecções por Nematoides , Doenças dos Ovinos , Transcriptoma , Animais , Ovinos/parasitologia , Fígado/parasitologia , Fígado/metabolismo , Fígado/imunologia , Infecções por Nematoides/veterinária , Infecções por Nematoides/genética , Infecções por Nematoides/imunologia , Infecções por Nematoides/parasitologia , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/genética , Doenças dos Ovinos/imunologia , Imunidade Inata/genética , Nematoides/patogenicidade , Imunidade Adaptativa/genética , Gastroenteropatias/genética , Gastroenteropatias/parasitologia , Gastroenteropatias/imunologia , Gastroenteropatias/veterinária
8.
Int J Mol Sci ; 25(12)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38928141

RESUMO

Unlike sedentary plant-parasitic nematodes, migratory plant endoparasitic nematodes (MPENs) are unable to establish permanent feeding sites, and all developmental stages (except eggs) can invade and feed on plant tissues and can be easily overlooked because of the unspecific symptoms. They cause numerous economic losses in agriculture, forestry, and horticulture. In order to understand the pathogenetic mechanism of MPENs, here we describe research on functions and host targets focused on currently identified effectors from six MPENs, namely Radopholus similis, Pratylenchus spp., Ditylenchus destructor, Bursaphelenchus xylophilus, Aphelenchoides besseyi, and Hirschmanniella oryzae. This information will provide valuable insights into understanding MPEN effectors and for future fostering advancements in plant protection.


Assuntos
Interações Hospedeiro-Parasita , Doenças das Plantas , Plantas , Animais , Doenças das Plantas/parasitologia , Plantas/parasitologia , Nematoides/patogenicidade , Proteínas de Helminto/metabolismo
9.
J Helminthol ; 98: e45, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38828717

RESUMO

This review summarises studies on distribution, diversity, and prevalence of gastrointestinal helminth infections in wild ruminants in sub-Saharan Africa. The results showed that 109 gastrointestinal tract (GIT) helminth species or species complexes were recorded in 10 sub-Saharan African countries. South Africa reported the highest number of species because most studies were carried out in this country. Eighty-eight nematode species or species complexes were recorded from 30 wild ruminant species across eight countries. The genus Trichostrongylus recorded the highest number of species and utilised the highest number of wild ruminant species, and along with Haemonchus spp., was the most widely distributed geographically. Fifteen trematode species or species complexes were reported from seven countries. The genus Paramphistomum recorded the highest number of species, and Calicophoron calicophoron was the most commonly occurring species in sub-Saharan African countries and infected the highest number of hosts. Six cestode species or species complexes from one family were documented from 14 wild hosts in seven countries. Moniezia spp. were the most commonly distributed in terms of host range and geographically. Impala were infected by the highest number of nematodes, whilst Nyala were infected by the highest number of trematode species. Greater kudu and Impala harbored the largest number of cestodes. The prevalence amongst the three GIT helminths taxa ranged between 1.4% and 100% for nematodes, 0.8% and 100% for trematodes, and 1.4% and 50% for cestodes. There is still limited information on the distribution and diversity of GIT helminths in wild ruminants in most sub-Saharan African countries.


Assuntos
Trato Gastrointestinal , Helmintíase Animal , Helmintos , Ruminantes , Animais , África Subsaariana/epidemiologia , Ruminantes/parasitologia , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Helmintos/classificação , Helmintos/isolamento & purificação , Helmintos/genética , Trato Gastrointestinal/parasitologia , Prevalência , Animais Selvagens/parasitologia , Biodiversidade , Nematoides/classificação , Nematoides/isolamento & purificação
10.
Infect Dis Poverty ; 13(1): 48, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902844

RESUMO

BACKGROUND: Human parasitic infections caused by Adenophorean nematodes encompass a range of diseases, including dioctophymiasis, trichuriasis, capillariasis, trichinellosis, and myositis. These infection can result in adverse impacts on human health and cause societal and economic concerns in tropical and subtropical regions. METHODS: This review conducted searches in PubMed, Embase and Google Scholar for relevant studies that published in established databases up to April 26, 2024. Studies that focused on the common morphology, life cycle, disease distribution, clinical manifestations, and prevention and control strategies for Adenophorean parasitic diseases in humans were included. RESULTS: Adenophorean nematodes exhibit shared morphological characteristics with a four-layered cuticle; uninucleate epidermal cells; pseudocoelom with six or more coelomocytes; generally three caudal glands; five esophageal glands; two testes in males with median-ventral supplementary glands in a single row; tail in males rarely possessing caudal alae; amphids always postlabial; presence of cephalic sensory organs; absence of phasmids; and a secretory-excretory system consisting of a single ventral gland cell, usually with a non-cuticularized terminal duct. Humans play two important roles in the life cycle of the nematode class, Adenophorea: 1) as a definitive host infected by ingesting undercooked paratenic hosts, embryonated eggs, infective larvae in fish tissue and meat contaminated with encysted or non-encysted larvae, and 2) as an accidental host infected by ingesting parasitic eggs in undercooked meat. Many organs are targeted by the Adenophorean nematode in humans such as the intestines, lungs, liver, kidneys, lymphatic circulation and blood vessels, resulting in gastrointestinal problems, excessive immunological responses, cell disruption, and even death. Most of these infections have significant incidence rates in the developing countries of Africa, Asia and Latin America; however, some parasitic diseases have restricted dissemination in outbreaks. To prevent these diseases, interventions together with education, sanitation, hygiene and animal control measures have been introduced in order to reduce and control parasite populations. CONCLUSIONS: The common morphology, life cycle, global epidemiology and pathology of human Adenophorean nematode-borne parasitic diseases were highlighted, as well as their prevention and control. The findings of this review will contribute to improvement of monitoring and predicting human-parasitic infections, understanding the relationship between animals, humans and parasites, and preventing and controlling parasitic diseases.


Assuntos
Saúde Global , Animais , Humanos , Estágios do Ciclo de Vida , Nematoides/fisiologia , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/prevenção & controle , Infecções por Nematoides/parasitologia
11.
Sci Rep ; 14(1): 13712, 2024 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-38877177

RESUMO

The family Acuariidae is a speciose group of parasitic nematodes, infecting mostly birds as definitive hosts. This study focused on the characterization of two species of acuariids, collected in two different species of piscivorous birds, the European great cormorant Phalacrocorax carbo sinensis from Italy, and the pygmy cormorant Microcarbo pygmaeus from Israel. Parasites were analyzed using light and scanning electron microscopy and by amplification and sequencing of the 28S rDNA. The results of morphological and molecular analyses showed that Ph. carbo sinensis was infected by the acuariid Syncuaria squamata (12 females) and Cosmocephalus obvelatus (1 female), whereas M. pygmaeus was infected by C. obvelatus (2 males, 12 females). The present results provide new data on the distribution of acuariid parasites of piscivorous birds, the first report of Acuariidae in Israel, and the first molecular data on S. squamata and C. obvelatus, which will be useful in future epidemiological and phylogenetic studies of these widely distributed, but less molecularly studied parasites.


Assuntos
Aves , Filogenia , Animais , Aves/parasitologia , Feminino , Masculino , Doenças das Aves/parasitologia , Doenças das Aves/epidemiologia , Nematoides/genética , Nematoides/classificação , Israel , Itália , RNA Ribossômico 28S/genética
12.
Nat Commun ; 15(1): 5137, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879542

RESUMO

Unravelling the multifaceted and bidirectional interactions between microbiota and host physiology represents a major scientific challenge. Here, we utilise the nematode model, Pristionchus pacificus, coupled to a laboratory-simulated decay process of its insect host, to mimic natural microbiota succession and investigate associated tripartite interactions. Metagenomics reveal that during initial decay stages, the population of vitamin B-producing bacteria diminishes, potentially due to a preferential selection by nematodes. As decay progresses to nutrient-depleted stages, bacteria with smaller genomes producing less nutrients become more prevalent. Lipid utilisation and dauer formation, representing key nematode survival strategies, are influenced by microbiota changes. Additionally, horizontally acquired cellulases extend the nematodes' reproductive phase due to more efficient foraging. Lastly, the expressions of Pristionchus species-specific genes are more responsive to natural microbiota compared to conserved genes, suggesting their importance in the organisms' adaptation to its ecological niche. In summary, we show the importance of microbial successions and their reciprocal interaction with nematodes for insect decay in semi-artificial ecosystems.


Assuntos
Besouros , Ecossistema , Microbiota , Nematoides , Animais , Besouros/microbiologia , Besouros/fisiologia , Microbiota/fisiologia , Nematoides/microbiologia , Nematoides/fisiologia , Metagenômica , Bactérias/genética , Bactérias/classificação , Bactérias/metabolismo , Celulases/metabolismo , Celulases/genética
13.
PLoS One ; 19(6): e0304663, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38843239

RESUMO

The productivity of agricultural ecosystems is heavily influenced by soil-dwelling organisms. To optimize agricultural practices and management, it is critical to know the composition, abundance, and interactions of soil microorganisms. Our study focused on Acrobeles complexus nematodes collected from tomato fields in South Africa and analyzed their associated bacterial communities utilizing metabarcoding analysis. Our findings revealed that A. complexus forms associations with a wide range of bacterial species. Among the most abundant species identified, we found Dechloromonas sp., a bacterial species commonly found in aquatic sediments, Acidovorax temperans, a bacterial species commonly found in activated sludge, and Lactobacillus ruminis, a commensal motile lactic acid bacterium that inhabits the intestinal tracts of humans and animals. Through principal component analysis (PCA), we found that the abundance of A. complexus in the soil is negatively correlated with clay content (r = -0.990) and soil phosphate levels (r = -0.969) and positively correlated with soil sand content (r = 0.763). This study sheds light on the bacterial species associated to free-living nematodes in tomato crops in South Africa and highlights the occurrence of various potentially damaging and beneficial nematode-associated bacteria, which can in turn, impact soil health and tomato production.


Assuntos
Produtos Agrícolas , Nematoides , Microbiologia do Solo , Solanum lycopersicum , Animais , Solanum lycopersicum/microbiologia , Solanum lycopersicum/parasitologia , África do Sul , Produtos Agrícolas/parasitologia , Produtos Agrícolas/microbiologia , Nematoides/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Solo/parasitologia , RNA Ribossômico 16S/genética , Análise de Componente Principal
14.
BMC Genomics ; 25(1): 615, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890582

RESUMO

BACKGROUND: Nematodes are the most abundant and diverse metazoans on Earth, and are known to significantly affect ecosystem functioning. A better understanding of their biology and ecology, including potential adaptations to diverse habitats and lifestyles, is key to understanding their response to global change scenarios. Mitochondrial genomes offer high species level characterization, low cost of sequencing, and an ease of data handling that can provide insights into nematode evolutionary pressures. RESULTS: Generally, nematode mitochondrial genomes exhibited similar structural characteristics (e.g., gene size and GC content), but displayed remarkable variability around these general patterns. Compositional strand biases showed strong codon position specific G skews and relationships with nematode life traits (especially parasitic feeding habits) equal to or greater than with predicted phylogeny. On average, nematode mitochondrial genomes showed low non-synonymous substitution rates, but also high clade specific deviations from these means. Despite the presence of significant mutational saturation, non-synonymous (dN) and synonymous (dS) substitution rates could still be significantly explained by feeding habit and/or habitat. Low ratios of dN:dS rates, particularly associated with the parasitic lifestyles, suggested the presence of strong purifying selection. CONCLUSIONS: Nematode mitochondrial genomes demonstrated a capacity to accumulate diversity in composition, structure, and content while still maintaining functional genes. Moreover, they demonstrated a capacity for rapid evolutionary change pointing to a potential interaction between multi-level selection pressures and rapid evolution. In conclusion, this study helps establish a background for our understanding of the potential evolutionary pressures shaping nematode mitochondrial genomes, while outlining likely routes of future inquiry.


Assuntos
Genoma Mitocondrial , Genômica , Nematoides , Filogenia , Seleção Genética , Animais , Nematoides/genética , Genômica/métodos , Composição de Bases , Evolução Molecular , Códon/genética
15.
PLoS One ; 19(6): e0306390, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38935803

RESUMO

The economic impact of gastrointestinal (GI) nematode infections on livestock production is well documented worldwide. Increasing evidence supports the hypothesis that parasite colonization induces significant changes in the GI tract environment and, therefore, in the landscape where the microbiota and parasites occur. Understanding the interactions between bacterial and parasite populations in the digestive tract of livestock may be useful to design parasite control strategies based on microbiota modification. The aims of this work were to investigate the impact of the oxytetracycline-mediated manipulation of the gut microbial community on the composition of GI nematode populations in naturally infected sheep and to explore changes in the GI microbial communities after nematode population treatment with the anthelmintic compound monepantel. Extensive manipulation of the GI microbiota with a therapeutic dose of the long-acting oxytetracycline formulation did not induce significant changes in the GI nematode burden. The gut microbiota of treated animals returned to control levels 17 days after treatment, suggesting strong resilience of the sheep microbial community to antibiotic-mediated microbiota perturbation. A significant decrease of the bacterial Mycoplasmataceae family (Log2FC = -4, Padj = 0.001) and a marked increase of the Methanobacteriaceae family (Log2FC = 2.9, Padj = 0.018) were observed in the abomasum of sheep receiving the monepantel treatment. While a comprehensive evaluation of the interactions among GI mycoplasma, methanobacteria and nematode populations deserves further assessment, the bacteria-nematode population interactions should be included in future control programs in livestock production. Understanding how bacteria and parasites may influence each other in the GI tract environment may substantially contribute to the knowledge of the role of microbiota composition in nematode parasite establishment and the role of the parasites in the microbiota composition.


Assuntos
Microbioma Gastrointestinal , Trato Gastrointestinal , Nematoides , Infecções por Nematoides , Oxitetraciclina , Doenças dos Ovinos , Animais , Ovinos/parasitologia , Ovinos/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/microbiologia , Doenças dos Ovinos/tratamento farmacológico , Infecções por Nematoides/veterinária , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Infecções por Nematoides/microbiologia , Nematoides/microbiologia , Nematoides/efeitos dos fármacos , Nematoides/fisiologia , Oxitetraciclina/farmacologia , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/parasitologia , Aminoacetonitrila/análogos & derivados , Aminoacetonitrila/farmacologia , Bactérias/efeitos dos fármacos
16.
Sci Rep ; 14(1): 14296, 2024 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-38906980

RESUMO

As the most abundant animal in the soil, nematodes are directly or indirectly involved in almost all soil ecological processes. Studying soil nematode population regulation is essential to understanding soil ecological processes. This study found urea combines nematode-trapping fungi to regulate the population of soil nematodes. In soil, compared with no urea, adding 0.2 mg/mL urea after applying Arthrobotrys oligospora and Dactylellina ellipsospora reduced the number of nematodes by 34.7% and 31.7%. Further, the mechanism of urea couple nematode-trapping fungi to regulate the nematode population was explored in the medium environment. The results showed that the addition of 0.2 mg/ml urea accelerated the trap formation of A. oligospora and D. ellipsosporas by 50% and 46.5%, and increased the yield of traps of A. oligospora and D. ellipsosporas by 39.5% and 40.6%, thus, the predatory efficiency of A. oligospora and D. ellipsospora on nematodes was increased by 34.2% and 32.7%. In conclusion, urea regulates the predation ability of A. oligospora and D. ellipsosporas to regulate the soil nematode population. This study deepens the understanding of the regulatory pathways of the soil nematodes but also provides a potential new strategy for harmful nematode bio-control.


Assuntos
Nematoides , Microbiologia do Solo , Solo , Ureia , Animais , Ureia/farmacologia , Ureia/metabolismo , Nematoides/fisiologia , Solo/parasitologia , Solo/química , Ascomicetos/fisiologia , Controle Biológico de Vetores/métodos
17.
An Acad Bras Cienc ; 96(3): e20230339, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38896740

RESUMO

Cucullanus lithodorasi n. sp. (Nematoda: Cucullanidae), collected from the intestine of Lithodoras dorsalis (Siluriformes) and waters of the north coast of Brazil is described based on light and scanning electron microscopic observations. The new species differs from its congeners in the number and arrangement of cloacal papillae: five precloacal pairs and five postcloacal pairs and presence of unpaired ventral papillae located slightly anterior to the cloaca. This is the third nominal species of the genus infecting fishes from brackish water from Brazil.


Assuntos
Peixes-Gato , Doenças dos Peixes , Microscopia Eletrônica de Varredura , Animais , Brasil , Peixes-Gato/parasitologia , Doenças dos Peixes/parasitologia , Masculino , Feminino , Nematoides/classificação , Nematoides/anatomia & histologia , Nematoides/ultraestrutura , Nematoides/isolamento & purificação
18.
Rev Bras Parasitol Vet ; 33(2): e019723, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38896756

RESUMO

Ctenocephalides felis felis is a relevant and widely distributed ectoparasite that acts as a vector of disease-causing pathogens. Moreover, it is responsible for economic losses due the use of harmful chemicals to the environment and that favor the emergence of insecticide-resistant populations. Research on entomopathogenic nematodes may open up an alternative route to the insect chemical control. The present study aimed to evaluate the killing efficacy of Heterorhabditis bacteriophora (HP88) against C. felis larvae in 400 µL, 600 µL and 1000 µL of suspension containing 120, 160 and 200 infective juveniles/larva and 600 µL of suspension containing the same concentrations of Heterorhabditis indica (LPP30), divided into two groups (absence and presence of diet) and a control group with three replications containing only distilled water. In the bioassay with H. bacteriophora, the groups in 600 µL of suspension showed higher mortality rates than those in the other tested volumes, which were above 80% at all concentrations. On the other hand, H. indica achieved mortality rates above 70% at all concentrations used. Results indicate that flea larvae are susceptible to in vitro infection by H. bacteriophora and H. indica.


Assuntos
Ctenocephalides , Larva , Animais , Larva/crescimento & desenvolvimento , Ctenocephalides/crescimento & desenvolvimento , Controle Biológico de Vetores , Nematoides
19.
J Helminthol ; 98: e39, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38726571

RESUMO

During nematode surveys of natural vegetation in forests of La Cima de Copey de Dota, San José, San José province, Costa Rica, a Xenocriconemella species closely resembling X. macrodora and related species was found. Integrative taxonomical approaches demonstrated that it is a new species described herein as X. costaricense sp. nov. The new species is parthenogenetic (only females have been detected) and characterised by a short body (276-404 µm); lip region with two annuli, not offset, not separated from body contour; first lip annulus partially covering the second lip annulus. Stylet thin, very long (113-133 µm) and flexible, occupying 30.5-47.8% of body length. Excretory pore located from one or two annuli anterior to one or two annuli posterior to level of stylet knobs, at 42 (37-45) µm from anterior end. Female genital tract monodelphic, prodelphic, outstretched, and occupying 35-45% of body length, with vagina slightly ventrally curved (14-18 µm long). Anus located 6-11 annuli from the tail terminus. Tail conoid and bluntly rounded terminus, the last 2-3 annuli oriented dorsally. Results of molecular characterisation and phylogenetic analyses of D2-D3 expansion segments of 28S rRNA, ITS, and partial 18S rRNA, as well as cytochrome oxidase c subunit 1 gene sequences further characterised the new species and clearly separated it from X. macrodora and other related species (X. iberica, X. paraiberica, and X. pradense).


Assuntos
Filogenia , Animais , Costa Rica , Feminino , Masculino , Nematoides/classificação , Nematoides/anatomia & histologia , Nematoides/genética , DNA Ribossômico/genética , RNA Ribossômico 28S/genética , DNA de Helmintos/genética , Florestas , Análise de Sequência de DNA
20.
J Biosci ; 492024.
Artigo em Inglês | MEDLINE | ID: mdl-38726821

RESUMO

Disease cross-transmission between wild and domestic ungulates can negatively impact livelihoods and wildlife conservation. In Pin valley, migratory sheep and goats share pastures seasonally with the resident Asiatic ibex (Capra sibirica), leading to potential disease cross-transmission. Focussing on gastro-intestinal nematodes (GINs) as determinants of health in ungulates, we hypothesized that infection on pastures would increase over summer from contamination by migrating livestock. Consequently, interventions in livestock that are well-timed should reduce infection pressure for ibex. Using a parasite life-cycle model, that predicts infective larval availability, we investigated GIN transmission dynamics and evaluated potential interventions. Migratory livestock were predicted to contribute most infective larvae onto shared pastures due to higher density and parasite levels, driving infections in both livestock and ibex. The model predicted a c.30-day antiparasitic intervention towards the end of the livestock's time in Pin would be most effective at reducing GINs in both hosts. Albeit with the caveats of not being able to provide evidence of interspecific parasite transmission due to the inability to identify parasite species, this case demonstrates the usefulness of our predictive model for investigating parasite transmission in landscapes where domestic and wild ungulates share pastures. Additionally, it suggests management options for further investigation.


Assuntos
Cabras , Gado , Animais , Índia/epidemiologia , Cabras/parasitologia , Gado/parasitologia , Ovinos/parasitologia , Migração Animal , Doenças das Cabras/parasitologia , Doenças das Cabras/transmissão , Animais Selvagens/parasitologia , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/transmissão , Doenças dos Ovinos/prevenção & controle , Infecções por Nematoides/transmissão , Infecções por Nematoides/veterinária , Infecções por Nematoides/prevenção & controle , Infecções por Nematoides/parasitologia , Infecções por Nematoides/epidemiologia , Estações do Ano , Larva/parasitologia , Nematoides/patogenicidade
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