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1.
Methods Mol Biol ; 2756: 257-270, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427298

RESUMO

Nematodes form various associations with soil microbiome. Experimental studies on nematode-attached microbes can improve mechanistic understanding of these associations and lead to new discoveries relevant for the field of nematode biocontrol. Microbial attachment to the surface of phytonematodes is very specific and influenced by a multitude of factors, including the designation of nematodes and microbes, environmental and biological factors in soil, time of incubation, and the ratio and evolutionary trajectories between nematodes and microbes. Here, we describe how the classical nematological and microbiological techniques can be coupled with the advanced molecular tools to study the microbial attachment to phytonematodes in soil. We focus on the characterization of nematode-attached microbes using classical microbiological approaches and high-throughput amplicon sequencing and on the effects of nematode-attached microbes on plant defense responses.


Assuntos
Microbiota , Nematoides , Animais , Microbiologia do Solo , Solo , Fatores Biológicos
2.
Methods Mol Biol ; 2756: 1-70, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427292

RESUMO

The study of nematodes requires availability of nematode specimens and their population densities in plants and soil. This can be achieved using adequate sampling schemes and extraction methods. In this chapter, the most common and suitable sampling and extraction procedures and equipment are described. These include the use of Baermann's funnels, Cobb's decanting and sieving, floating methods such as the Oostenbrink method and Fenwick can, elutriators such as Seinhorst methods, centrifugation methods including that of Coolen, and mechanical and enzymatic maceration. The combination of different methods for cleaning the nematode suspensions is described, such as Cobb's sieving with Baermann's funnels or centrifugation, and for cysts combining Seinhorst's elutriator or Fenwick can with the alcohol methods. Methods for extraction of eggs and/or juveniles of cyst and egg mass forming nematodes, to be used as inoculum or to ascertain egg viability, are also described. Only little information is also noted on the use of molecular tools to identify and quantify nematode populations in soil and roots.


Assuntos
Nematoides , Tylenchida , Animais , Plantas , Solo , Raízes de Plantas/parasitologia
3.
Methods Mol Biol ; 2756: 271-289, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427299

RESUMO

Plant-parasitic nematodes have enormous economic and social impacts. The majority of plant-parasitic nematodes are soil dwelling and feed on plant roots. Exudates from actively growing roots initiate hatch of some nematode species, thus ensuring infective juveniles emerge in close proximity to host plant roots. Several gradients of volatile and non-volatile compounds are established around plant roots, at least some of which are used by nematodes to orientate toward the roots. Plant-parasitic nematodes are microscopic in size (less than 1 mm in length and between 15 and 20 µm in diameter), so investigations into behavior are challenging. Various in vitro techniques have been used to evaluate the effects of root exudates. The techniques can also be used to evaluate the comparative attractiveness of different plants or cultivars of the same plant species. This chapter describes some examples of different types of basic in vitro assays.


Assuntos
Nematoides , Tylenchida , Tylenchoidea , Animais , Raízes de Plantas/parasitologia , Exsudatos e Transudatos , Solo
4.
Methods Mol Biol ; 2756: 247-255, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427297

RESUMO

DGGE (denaturing gradient gel electrophoresis) is a nucleic acid separation technique applied to the evaluation of microbial biodiversity. This technique is quite rapid and cheap compared to other types of analysis. Here we describe the comparison of nematode communities inhabiting different ecosystems. After an ecologically representative sampling collection and the nematode extraction from soil, nematodes are centrifuged in Eppendorf tubes to facilitate DNA extraction. DNA from the whole community of each type of soil is extracted, amplified with primers for 18 S rDNA and used in DGGE analysis. The profiles of DGGE can be analyzed with appropriate software, and biodiversity indices can be estimated.


Assuntos
Ecossistema , Nematoides , Animais , Biodiversidade , DNA Ribossômico/genética , Reação em Cadeia da Polimerase/métodos , Nematoides/genética , Solo , Eletroforese em Gel de Poliacrilamida , DNA Bacteriano/genética , RNA Ribossômico 16S/genética , Microbiologia do Solo
5.
Methods Mol Biol ; 2756: 291-304, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427300

RESUMO

Full compatible interactions between crop plants and endoparasitic sedentary nematodes (ESNs) lead to severe infestation of the roots and plant growth impairing, as well as to the increase of nematode population in the soil that is a threat for the next planting crop. In the absence of activators, basic plant defense is overcome by nematode secretion of effectors that suppress defense gene expression, inhibit ROS generation and the oxidative burst used by plants to hamper nematode feeding site settlement and limit its development and reproduction. Activators can be exogenously added as a preventive measure to prime plants and strengthen their defense against ESNs. Activators can be an array of antioxidant compounds or biocontrol agents, such as mutualist microorganisms living in the rhizosphere (biocontrol fungi (BCF), arbuscular mycorrhizal fungi (AMF), plant growth-promoting bacteria (PGPB), etc.). In this chapter, methods are described for usage of both salicylic acid (SA) and its methylated form (Met-SA), and BCF/AMF as elicitors of resistance of vegetable crops against root-knot nematodes (RKNs). The rhizosphere-living BCF/AMF were recovered from commercial formulates pre-incubated in suitable growth media and provided exclusively as soil drench of potted plants. The plant hormones SA and Met-SA were provided to plants as soil drench, foliar spray, and root dip. It is indicated that activators' dosages and plant age are crucial factors in determining the success of a pre-treatment to reduce nematode infection. Therefore, dosages should be expressed as amounts of activators per g of plant weight at treatment. Thresholds exist above which dosages start to work; overdoses were found to be toxic to plants and useless as activators.


Assuntos
Micorrizas , Nematoides , Animais , Agentes de Controle Biológico/metabolismo , Doenças das Plantas/genética , Raízes de Plantas/metabolismo , Nematoides/metabolismo , Ácido Salicílico/farmacologia , Ácido Salicílico/metabolismo , Micorrizas/metabolismo , Produtos Agrícolas/metabolismo , Solo
6.
Methods Mol Biol ; 2756: 343-350, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427304

RESUMO

Heat shock proteins (HSPs) in all animals studied to date constitute potential indicators of stress, under various environmental conditions. The goal of this chapter is to show, for the first time, the suitability of the approach based on evaluation of the expression levels of heat shock proteins, as good indicators of stress induced in nematodes by the cultivation of resistant plant varieties or by other potential stressors.


Assuntos
Proteínas de Choque Térmico , Nematoides , Animais , Proteínas de Choque Térmico/metabolismo , Nematoides/metabolismo , Proteínas de Plantas/metabolismo , Resposta ao Choque Térmico , Proteínas de Choque Térmico HSP70/metabolismo
7.
Methods Mol Biol ; 2756: 305-316, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427301

RESUMO

Reactive oxygen species (ROS) accumulation is one of the earliest hallmarks upon successful pathogen recognition in plants. H2O2 is considered the most important ROS in plant defense considering its relatively high stability and capacity to cross long distances in the plant. However, ROS also play roles in cell development and could hence facilitate nematode feeding site development. Several methods to analyze the cellular redox state exist, among which ROS detection and quantification and the evaluation of ROS scavenging enzyme activity (peroxidase activity, catalase activity, etc.). Here, we describe DAB staining, which is used to detect and localize ROS in planta upon an external trigger. Furthermore, ROS quantification using the FOX assay is described. Both methods have been used extensively in research and yield repeatable results in various plants.


Assuntos
Peróxido de Hidrogênio , Nematoides , Animais , Espécies Reativas de Oxigênio , Plantas , Antioxidantes
8.
Methods Mol Biol ; 2756: 351-382, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427305

RESUMO

The growing interest in the use of entomopathogenic nematodes and their symbiotic bacteria as promising biocontrol agents of many arthropod pests and pathogens has created running technologies to expand their use globally. The related laboratory procedures and tests on these nematodes such as their isolation, count, culture, identification, pathogenicity, virulence, and environmental tolerance should form the solid basis for such an expansion with reliable uses. Extensive practical details of such procedures and tests as well as how to identify and overcome the problems associated with these aspects are addressed in this chapter.


Assuntos
Artrópodes , Nematoides , Animais , Controle Biológico de Vetores/métodos , Reprodução , Simbiose
9.
Proc Biol Sci ; 291(2018): 20232653, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38471558

RESUMO

Extreme environments enable the study of simplified food-webs and serve as models for evolutionary bottlenecks and early Earth ecology. We investigated the biodiversity of invertebrate meiofauna in the benthic zone of the Great Salt Lake (GSL), Utah, USA, one of the most hypersaline lake systems in the world. The hypersaline bays within the GSL are currently thought to support only two multicellular animals: brine fly larvae and brine shrimp. Here, we report the presence, habitat, and microbial interactions of novel free-living nematodes. Nematode diversity drops dramatically along a salinity gradient from a freshwater river into the south arm of the lake. In Gilbert Bay, nematodes primarily inhabit reef-like organosedimentary structures built by bacteria called microbialites. These structures likely provide a protective barrier to UV and aridity, and bacterial associations within them may support life in hypersaline environments. Notably, sampling from Owens Lake, another terminal lake in the Great Basin that lacks microbialites, did not recover nematodes from similar salinities. Phylogenetic divergence suggests that GSL nematodes represent previously undescribed members of the family Monhysteridae-one of the dominant fauna of the abyssal zone and deep-sea hydrothermal vents. These findings update our understanding of halophile ecosystems and the habitable limit of animals.


Assuntos
Ecossistema , Nematoides , Animais , Lagos/química , Filogenia , Bactérias
10.
Front Cell Infect Microbiol ; 14: 1296769, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476164

RESUMO

Intestinal parasitic infections caused by helminths are globally distributed and are a major cause of morbidity worldwide. Parasites may modulate the virulence, gut microbiota diversity and host responses during infection. Despite numerous works, little is known about the complex interaction between parasites and the gut microbiota. In the present study, the complex interplay between parasites and the gut microbiota was investigated. A total of 12 bacterial strains across four major families, including Enterobacteriaceae, Morganellaceae, Flavobacteriaceae, and Pseudomonadaceae, were isolated from Channa punctata, infected with the nematode species Aporcella sp., Axonchium sp., Tylencholaimus mirabilis, and Dioctophyme renale. The findings revealed that nematode infection shaped the fish gut bacterial microbiota and significantly affected their virulence levels. Nematode-infected fish bacterial isolates are more likely to be pathogenic, with elevated hemolytic activity and biofilm formation, causing high fish mortality. In contrast, isolates recovered further from non-parasitised C. punctata were observed to be non-pathogenic and had negligible hemolytic activity and biofilm formation. Antibiogram analysis of the bacterial isolates revealed a disproportionately high percentage of bacteria that were either marginally or multidrug resistant, suggesting that parasitic infection-induced stress modulates the gut microenvironment and enables colonization by antibiotic-resistant strains. This isolation-based study provides an avenue to unravel the influence of parasitic infection on gut bacterial characteristics, which is valuable for understanding the infection mechanism and designing further studies aimed at optimizing treatment strategies. In addition, the cultured isolates can supplement future gut microbiome studies by providing wet lab specimens to compare (meta)genomic information discovered within the gut microenvironment of fish.


Assuntos
Microbioma Gastrointestinal , Helmintos , Enteropatias Parasitárias , Nematoides , Parasitos , Humanos , Animais , Microbioma Gastrointestinal/fisiologia , Bactérias , Peixes , Imunidade
11.
PLoS One ; 19(3): e0298400, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38478489

RESUMO

Facultative parasites can alternate between a free-living and a parasitic existence to complete their life cycle. Yet, it remains uncertain which lifestyle they prefer. The optimal foraging theory suggests that food preferences align with fitness benefits. To test this hypothesis, we investigated the facultative parasite nematode Rhabditis regina, assessing its host preference and the associated benefits. Two experiments were conducted using wild nematode populations collected from Phyllophaga polyphylla, their natural host. In the first experiment, we used a behavioral arena to assess host preference between the natural host and two experimental hosts: Spodoptera frugiperda which is an alternative host and dead Tenebrio molitor, which simulates a saprophytic environment. In the second experiment, we subjected wild nematodes to "experimental evolution" lasting 50 generations in S. frugiperda and 53 generations in T. molitor carcass. We then compared life history traits (the size, survival, number of larvae, and glycogen and triglycerides as energy reserves) of dauer larvae with those nematodes from P. polyphylla (control group). We found a significant preference for P. polyphylla, which correlated with higher values in the nematode's life history traits. In contrast, the preference for S. frugiperda and the saprophytic environment was lower, resulting in less efficient life history traits. These findings align with the optimal foraging theory, as the nematode's parasitic preferences are in line with maximizing fitness. This also indicates that R. regina exhibits specificity to P. polyphylla and is better adapted to a parasitic lifestyle than a free-living one, suggesting an evolutionary pathway towards parasitism.


Assuntos
Besouros , Nematoides , Parasitos , Rhabditoidea , Animais , Larva/parasitologia , Interações Hospedeiro-Parasita
12.
Zootaxa ; 5410(1): 134-144, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38480252

RESUMO

There are very few taxonomic studies of Brazilian sipunculan worms, and the species occurring along the northern coasts are largely understudied. We report herein the occurrence of four shallow water species along the intertidal zones of Bahia and Pernambuco states. Antillesoma antillarum (Grbe & Oersted, 1858) occurs from underneath beach rocks or within sandstone reefs and may reach high densities. The large species Sipunculus (Sipunculus) nudus Linnaeus, 1766, Sipunculus polymyotus Fisher, 1947, and Xenosiphon branchiatus (Fischer, 1895) were collected in sandy-mud, low-energy intertidal environments. For the first time, we report that sipunculans are collected and used as fishing bait by local fishermen in the Western Atlantic. All species are fully described, including notes on their external and internal anatomy.


Assuntos
Anelídeos , Nematoides , Animais , Brasil
13.
Parasite ; 31: 14, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38488705

RESUMO

Filarial nematodes of the Dipetalonema lineage include tick-borne filarioids that infect both domestic and wild vertebrate hosts, but they remain understudied in many cases. In this study, we conducted a molecular characterization of a Dipetalonema-like filarioid (DLF) recently identified in two tick species in French Guiana, South America. While the cox1 mitochondrial gene was the sole marker initially sequenced for describing DLF, its classification and phylogenetic relationship with other members of the Dipetalonema lineage were unclear. Therefore, we better characterized DLF through the sequencing of six additional gene markers and conducted phylogenetic analyses. Based on this multi-locus typing scheme, DLF exhibited significant divergence from known genera and species of filarioids, or other sequences available in public databases, suggesting its potential classification as a novel genus within the Dipetalonema lineage. Phylogenetic analyses further unveiled a close evolutionary relationship between DLF and all other filarioids associated with Acari (ticks and mites) within a robust monophyletic subclade in the Dipetalonema lineage. Overall, these findings confirm the existence of a specialized, Acari-borne group of filarioids and underscore the need for comprehensive investigations into their epidemiology and potential impact on animal health.


Title: Une analyse de séquences multi-locus dévoile un nouveau genre de nématodes filaires, associé aux tiques en Guyane française. Abstract: Les filaires de la lignée Dipetalonema comprennent des espèces transmises par les tiques qui infectent à la fois des hôtes vertébrés domestiques et sauvages, mais qui restent sous-étudiées dans de nombreux cas. Dans cette étude, nous avons réalisé une caractérisation moléculaire d'un filarioïde ressemblant à Dipetalonema (FRD) récemment identifié dans deux espèces de tiques en Guyane française. Alors que la séquence du gène mitochondrial cox1 était le seul marqueur génétique initialement séquencé pour décrire FRD, sa classification et sa relation phylogénétique avec d'autres membres de la lignée Dipetalonema étaient incertaines. Par conséquent, nous avons caractérisé plus précisément DLF en séquençant six gènes supplémentaires et en réalisant des analyses phylogénétiques. Sur la base de ce typage multi-locus, FRD présentait une divergence significative par rapport aux genres et espèces connus de filarioïdes, ou à d'autres séquences disponibles dans les bases de données publiques, suggérant sa classification potentielle en tant que nouveau genre au sein de la lignée Dipetalonema. Les analyses phylogénétiques ont en outre révélé une relation évolutive étroite entre FRD et tous les autres filarioïdes associés aux tiques et acariens au sein d'un sous-clade monophylétique dans la lignée Dipetalonema. Dans l'ensemble, ces résultats confirment l'existence d'un groupe spécialisé de filarioïdes transmis par les tiques et acariens et soulignent la nécessité d'études approfondies sur leur épidémiologie et leur impact potentiel sur la santé animale.


Assuntos
Ácaros e Carrapatos , Nematoides , Carrapatos , Animais , Filogenia , Guiana Francesa/epidemiologia , Análise de Sequência
14.
Parasit Vectors ; 17(1): 141, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500187

RESUMO

BACKGROUND: Wild deer populations utilizing livestock grazing areas risk cross-species transmission of gastrointestinal nematode parasites (GINs), including GINs with anthelmintic resistance (AR) traits. Wild deer have been shown to carry problematic GIN species such as Haemonchus contortus and Trichostrongylus species in the UK, but the presence of livestock GINs in Northern Ireland deer populations is unknown. Also, is it not known whether AR traits exist among GINs of deer such as Ostertagia leptospicularis and Spiculopteragia asymmetrica in pastureland where anthelmintics are heavily used. METHODS: Adult-stage GIN samples were retrieved from Northern Irish wild fallow deer abomasa. Individual specimens were subject to a species-specific PCR analysis for common sheep and cattle GIN species with ITS-2 sequence analysis to validate species identities. In addition, the beta-tubulin gene was subject to sequencing to identify benzimidazole (BZ) resistance markers. RESULTS: ITS-2 sequencing revealed O. leptospicularis and S. asymmetrica, but species-specific PCR yielded false-positive hits for H. contortus, Teladorsagia circimcincta, Trichostrongylus axei, T. colubriformis, T. vitrinus and Ostertagia ostertagi. For beta-tubulin, O. leptospicularis and S. asymmetrica yielded species-specific sequences at the E198 codon, but no resistance markers were identified in either species at positions 167, 198 or 200 of the coding region. DISCUSSION: From this report, no GIN species of significance in livestock were identified among Northern Ireland fallow deer. However, false-positive PCR hits for sheep and cattle-associated GINs is concerning as the presence of deer species in livestock areas could impact both deer and livestock diagnostics and lead to overestimation of both GIN burden in deer and the role as of deer as drivers of these pathogens. ITS-2 sequences from both O. leptospicularis and S. asymmetrica show minor sequence variations to geographically distinct isolates. AR has been noted among GINs of deer but molecular analyses are lacking for GINs of wildlife. In producing the first beta-tubulin sequences for both O. leptospicularis and S. asymmetrica, we report no BZ resistance in this cohort. CONCLUSIONS: This work contributes to genetic resources for wildlife species and considers the implications of such species when performing livestock GIN diagnostics.


Assuntos
Anti-Helmínticos , Cervos , Nematoides , Trichostrongyloidea , Humanos , Animais , Bovinos , Ovinos , Cervos/parasitologia , Ostertagia/genética , Animais Selvagens , Gado , Tubulina (Proteína)/genética , Irlanda do Norte/epidemiologia , Trichostrongyloidea/genética , Anti-Helmínticos/uso terapêutico , Trichostrongylus
15.
Microbiol Res ; 282: 127669, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38442455

RESUMO

Body size is an important life-history trait that affects organism niche occupancy and ecological interactions. However, it is still unclear to what extent the assembly process of organisms with different body sizes affects soil biogeochemical cycling processes at the aggregate level. Here, we examined the diversity and community assembly of soil microorganisms (bacteria, fungi, and protists) and microfauna (nematodes) with varying body sizes. The microbial functional potential associated with carbon, nitrogen, phosphorus, and sulfur metabolism within three soil aggregate sizes (large macroaggregates, > 2 mm; small macroaggregates, 0.25-2 mm; and microaggregates, < 0.25 mm) were determined by metagenomics. We found that the smallest microbes (bacteria) had higher α-diversity and lower ß-diversity and were mostly structured by stochastic processes, while all larger organisms (fungi, protists, and nematodes) had lower α-diversity and were relatively more influenced by deterministic processes. Structural equation modeling indicated that the microbial functional potential associated with carbon, nitrogen, phosphorus, and sulfur metabolism was mainly influenced by the bacterial and protist diversity in microaggregates. In contrast, the microbial functional potential was primarily mediated by the assembly processes of four organism groups, especially the nematode community in macroaggregates. This study reveals the important roles of soil organisms with different body sizes in the functional potential related to nutrient cycling, and provides new insights into the ecological processes structuring the diversity and community assembly of organisms of different body sizes at the soil aggregate level, with implications for soil nutrient cycling dynamics.


Assuntos
Nematoides , Solo , Animais , Solo/química , Microbiologia do Solo , Fungos , Tamanho Corporal , Carbono , Nitrogênio , Fósforo , Enxofre
16.
Trop Anim Health Prod ; 56(2): 100, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38472670

RESUMO

Gastrointestinal nematodes (GIN) exacerbate the impact of droughts on the survival of cattle. The inadequacies of the conventional system make it increasingly important to explore indigenous knowledge (IK) to create drought-tolerant and GIN resilient herds. The objective of the study was to assess the indigenous strategies for controlling GIN during droughts. Face-to-face interviews with experts on IK were conducted to give insight into the importance, methods and ranking of GIN control. The experts identified 86 cattle that were used to test their assertions. The control methods used were identifying cattle that were susceptible to high GIN loads using predisposing factors, diagnosis of GIN burdens using faecal appearance, and treatment using phytotherapy. Experts ranked predisposing factors as the most critical control strategy and identified body condition, class, sex, coat colour, pregnancy status and lactation status as predisposing factors to high GIN burdens. Thin, older, dark-coloured cattle, as well as pregnant and lactating cows, were considered susceptible to GIN. However, pregnancy status, coat colour and sex were significantly associated with high GIN burdens. Cows were 2.6 times more likely to have high GIN burdens than bulls. Dark-coloured cattle were 3.5 times more likely to have high GIN burdens than light-coloured ones, and the likelihood of pregnant cows was 4.9 times higher than non-pregnant cows. A dark-coloured pregnant cow was extremely susceptible to high GIN burdens. In conclusion, knowledge of predisposing factors informs selection decisions when purchasing foundation stock. Cattle that are susceptible to high GIN loads are prioritised during droughts or culled where resources are scarce.


Assuntos
Doenças dos Bovinos , Nematoides , Feminino , Animais , Bovinos , Masculino , Gravidez , Lactação , Trato Gastrointestinal , África Austral
17.
PLoS One ; 19(3): e0298165, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38512937

RESUMO

Inundative biological control (biocontrol) efforts in pest management lead to the mass distribution of commercialized biocontrol agents. Many 'biocontrol gone awry' incidents have resulted in disastrous biodiversity impacts, leading to increased scrutiny of biocontrol efforts. The nematode Phasmarhabditis hermaphrodita is sold as a biocontrol agent on three continents and targets pest gastropods such as Deroceras reticulatum, the Grey Field Slug; P. hermaphrodita is not presently approved for use in the United States. Investigations into the potential for P. hermaphrodita to infect non-target gastropod species of conservation relevance, however, are limited. We examined the effects of three strains of P. hermaphrodita on mortality in Monadenia fidelis, the Pacific Sideband, a snail species endemic to the Pacific Northwest of North America, in laboratory conditions. Across a 71-day laboratory infectivity assay, snails exposed to each of the three nematode strains, each analyzed at two doses, experienced a mean 50% mortality by days 20-42. All nematode-treated snails were dead by the end of the study. By contrast, 30/30 water-control snails experienced no mortality. Nematodes killed smaller, juvenile-stage snails significantly faster than those in larger and more developmentally advanced hosts. Our results provide direct evidence that the biocontrol nematode P. hermaphrodita infects and kills M. fidelis, a non-target gastropod species endemic to the Pacific Northwest, in laboratory conditions. This study suggests that introduction of P. hermaphrodita to new ecosystems might negatively impact endemic gastropod biodiversity and advocates for further investigation of non-target effects, including in conditions closer to the natural environments of non-target species.


Assuntos
Gastrópodes , Nematoides , Rhabditoidea , Animais , Ecossistema , Controle Biológico de Vetores/métodos , Caramujos , América do Norte , Noroeste dos Estados Unidos , Biodiversidade
18.
Sci Rep ; 14(1): 6841, 2024 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-38514717

RESUMO

Gastrointestinal nematodes (GINs) are major constraints to health and productivity of small ruminants. Methods of their control relies mainly on anthelmintic drugs; however, the indiscriminate use of these drugs could lead to the development of anthelmintic resistance (AR). This study aimed to investigate the epidemiology of GINs infection, and field evaluation of anthelmintic efficacy in sheep. The epidemiological data were collected using a cross-sectional study design while a farm-based field study design was employed for the evaluation of anthelminthic efficacy. Furthermore, standard parasitological techniques were employed for qualitative and quantitative worm identification. The overall prevalence indicated 50.3%. Six genera of GINs (Haemonchus, Trichostrongylus, Oesophagostomum/Chabertia, Trichuris, Teladosargia/Ostertagia and Nematodirus) were identified. Among the identified genera, Haemonchus (25.4%) and Trichostrongylus (24.8%) were the dominant genera followed by mixed infection (21.8%), Oesophagostomum/Chabertia (10.4%), Trichuris (7.8%), Teladosargia (Ostertagia) (5.7%) and Nematodirus (4.1%). Mixed infections consisted either of double infections with Haemonchus and Trichostrongylus, or triple infections with Haemonchus, Trichostrongylus and Trichuris. The McMaster egg counting results showed that the mean EPG of infected sheep was 845.6. The results also showed 66 (34.2%), 101 (52.3%) and 26 (13.5%) sheep had low, moderate and heavy worm burden, respectively. Albendazole and Ivermectin showed low efficacy (percentage reductions = 90% and 92%; 95% lower confidence limit = 82.1% and 83.6% respectively) whereas Tetramisole was effective (FECR% = 96.8%; 95% LCL = 93.4%). Factors such as age, body condition, management system and past deworming history of sheep were found to have a statistically significant (p < 0.05) influence on the occurrence and burden of the worms. This is further explained as the highest prevalence and worm burden was detected in sheep of young age (p = 0.008; OR = 0.58; 95% CI = 0.39-0.87), poor body condition (p = 0.001; OR = 0.08; 95% CI = 0.04-0.16) and sheep kept under semi-intensive (p = 0.04; OR = 1.53; 95% CI = 1.02-2.29) with no deworming history for the last two months (p = 0.001; OR = 2.97; 95% CI = 1.94-4.56). The study results revealed that nematode infections were among sheep health constraints that could hurt their productivity while low efficacy of Albendazole and Ivermectin were detected. Therefore, the appropriate management techniques of GIN infections should be designed and implemented. Moreover, a further study involving more sensitive techniques (e.g. Mini-FLOTAC, molecular, and serological techniques) should be conducted by considering different host and environmental risk factors such as production level and seasons.


Assuntos
Anti-Helmínticos , Haemonchus , Nematoides , Infecções por Nematoides , Doenças dos Ovinos , Animais , Ovinos , Albendazol/uso terapêutico , Ivermectina/farmacologia , Etiópia/epidemiologia , Estudos Transversais , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/epidemiologia , Contagem de Ovos de Parasitas/veterinária , Anti-Helmínticos/uso terapêutico , Anti-Helmínticos/farmacologia , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/veterinária , Ruminantes , Trichostrongylus , Oesophagostomum , Trichuris , Fezes
19.
J Helminthol ; 98: e27, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38509853

RESUMO

A survey for slug- and snail-associated nematodes was conducted in forests, parks, botanical gardens, and nature reserves at 13 localities in Belgium to uncover more diversity of gastropod mollusc-associated nematodes and to characterise Pellioditis populations found in the country. A total of 319 slugs and snails belonging to nine species were examined. Arion vulgaris was the most commonly found mollusc species in this study (eight locations), and 19.4% of the examined mollusc specimens were found infected by nematodes. The highest prevalence of nematodes was observed in Cornu aspersum (60%) followed by A. vulgaris (34.8%), Limax maximus (28.6%), and Cepaea sp. (20%). Eleven nematode species belonging to eight families were isolated and identified from the mollusc hosts including Alloionema appendiculatum, Angiostoma dentiferum, A. gandavense, Angiostrongylus vasorum, Cosmocerca longicauda, Panagrolaimus cf. subelongatus, Pellioditis californica, P. hermaphrodita, Rhabditis sp., Tetrameres cf. fissispina, and Troglostrongylus cf. brevior.Pellioditis was the most commonly found nematode genus (at nine localities) and C. longicauda and P. californica were reported in Belgium for the first time. Co-infections of more than one nematode species were observed in eight (2.5%) molluscs specimens. Most co-infections consisted of two nematode species. In one A. vulgaris specimen, a co-infection of three nematode species (A. vasorum, P. hermaphrodita, and Tetrameres cf. fissispina) was observed. Four ex vivo cultures of P. californica and six ex vivo cultures of P. hermaphrodita were established from single hermaphrodites, and both species were described based on light microscopy, scanning electron microscopy, and morphometric, morphological, and molecular data.


Assuntos
Coinfecção , Gastrópodes , Nematoides , Rhabditoidea , Humanos , Animais , Bélgica/epidemiologia , Caramujos , Carne
20.
J Helminthol ; 98: e26, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38509862

RESUMO

Grapevine fanleaf virus (GFLV) is one of the most severe virus diseases of grapevines, causing fanleaf degeneration that is transmitted by Xiphinema index. This paper aims to isolate Xiphinema species from Tunisian vineyard soil samples and assess their ability to acquire and transmit GFLV under natural and controlled conditions. Based on morphological and morphometric analyses, Tunisian dagger nematodes were identified as X. index and Xiphinema italiae. These results were confirmed with molecular identification tools using species-specific polymerase chain reaction primers. The total RNA of GFLV was extracted from specimens of Xiphinema and amplified based on real-time polymerase chain reaction using virus-specific primers. Our results showed that X. index could acquire and transmit the viral particles of GFLV. This nepovirus was not detected in X. italiae, under natural conditions; however, under controlled conditions, this nematode was able to successfully acquire and transmit the viral particles of GFLV.


Assuntos
Nematoides , Nepovirus , Animais , RNA Viral/genética , Nematoides/genética , Nepovirus/genética , Vetores de Doenças , Doenças das Plantas
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