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Rationale: Matrix‐assisted laser desorption/ionisation‐mass spectrometry imaging (MALDI‐MSI) is a powerful label‐free technique for biomolecule detection (e.g., lipids), within tissue sections across various biological species. However, despite its utility in many applications, the nematode Caenorhabditis elegans is not routinely used in combination with MALDI‐MSI. The lack of studies exploring spatial distribution of biomolecules in nematodes is likely due to challenges with sample preparation. Methods: This study developed a sample preparation method for whole intact nematodes, evaluated using cryosectioning of nematodes embedded in a 10% gelatine solution to obtain longitudinal cross sections. The slices were then subjected to MALDI‐MSI, using a RapifleX Tissuetyper in positive and negative polarities. Samples were also prepared for liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) analysis using an Exploris 480 coupled to a HPLC Vanquish system to confirm the MALDI‐MSI results. Results: An optimised embedding method was developed for longitudinal cross‐sectioning of individual worms. To obtain longitudinal cross sections, nematodes were frozen at −80°C so that all worms were rod shaped. Then, the samples were defrosted and transferred to a 10% gelatine matrix in a cryomold; the worms aligned, and the whole cryomold submerged in liquid nitrogen. Using MALDI‐MSI, we were able to observe the distribution of lipids within C. elegans, with clear differences in their spatial distribution at a resolution of 5 μm. To confirm the lipids from MALDI‐MSI, age‐matched nematodes were subjected to LC‐MS/MS. Here, 520 lipids were identified using LC‐MS/MS, indicating overlap with MALDI‐MSI data. Conclusions: This optimised sample preparation technique enabled (un)targeted analysis of spatially distributed lipids within individual nematodes. The possibility to detect other biomolecules using this method thus laid the basis for prospective preclinical and toxicological studies on C. elegans. [ABSTRACT FROM AUTHOR]

Drug-resistant parasitic nematodes pose a grave threat to plants, animals, and humans. An innovative paradigm for treating parasitic nematodes is emphasized in this opinion. This approach relies on repurposing methuosis (a death characterized by accumulation of large vacuoles) inducing anticancer drugs as anthelmintics. We review drugs/chemicals that have shown to kill nematodes or cancerous cells by inducing multiple vacuoles that eventually coalesce and rupture. This perspective additionally offers a succinct summary on Structure–Activity Relationship (SAR) of methuosis-inducing small molecules. This strategy holds promise for the development of broad-spectrum anthelmintics, shedding light on shared molecular mechanisms between cancer and nematodes in response to these inducers, thereby potentially transforming both therapeutic domains. [ABSTRACT FROM AUTHOR]

Forty-seven faecal samples of wolves from Bejaia were examined for intestinal helminths. Five nematodes (Ancylostoma caninum (egg), Strongyloides stercoralis (larvae L1), Toxocara canis (egg), Toxascaris leonina (egg), and Trichuris vulpis (egg)), and one cestode (Dipylidium caninum) were identified. These nematodes were detected with a prevalence of 46.8%, 23.4%, 38.2%, 25.3%, and 2.12%, respectively; and a cestode, with a prevalence of 4.3%. Our results show a high relative abundance of Strongyloides stercoralis larvae L1 (37.5%), followed by eggs of Ancylostoma caninum, whether non-embryonated (16.77%) or embryonated (14.28%). Among the ascarids, Toxocara canis was represented with 18.1%, followed by Toxascaris leonina (8.1%). Finally, Dipylidium caninum and Trichuris vulpis were only poorly represented. This is the first study on helminth parasites in wild golden wolves in Bejaia. The results indicate the presence of six gastrointestinal helminths in the wolf population. [ABSTRACT FROM AUTHOR]

Nematodes of the Onchocercidae family, such as Pelecitus spp., are filarial parasites of medical and veterinary importance. Although infections are widely distributed among avian species, only 2 cases of human Pelecitus ocular infection, both in South America, have been reported. We describe a 61-year-old man in northeast Thailand diagnosed with an ocular infection. Morphologic characteristics suggested the causative agent was a female Pelecitus nematode: coiled body, rounded anterior and posterior extremities, a distinct preesophageal cuticular ring, lateral alae, a postdeirid, and a protuberant vulva. Sequences of the 12S rDNA gene indicated 95%–96% identity and cox1 gene 92%–96% identity with published P. copsychi sequences. P-distance for cox1 sequences between the causative agent and P. copsychi was 6.71%. Phylogenetic trees of 12S rDNA and cox1 genes indicated the species differed from but is closely associated with P. copsychi. Healthcare providers should be aware of the threat of ocular infection from Pelecitus spp. nematodes. [ABSTRACT FROM AUTHOR]

Pratylenchus neglectus and P. thornei are among the most destructive root lesion nematodes of wheat in the Pacific Northwest, United States of America and throughout the world. The aim of this study was to determine whether both nematode species were similar in their ability to induce defense genes in roots of wheat genotype Scarlet, and whether a combination of both species induced a different pattern of gene induction than each species alone. The long-term aspect of the research was to identify nematode-inducible promoters for deploying defense genes in roots in breeding programs. The root transcriptomes of genotype Scarlet were obtained after a one-week infection period with each nematode species separately, or both species combined. Root defense gene expression was induced for all three treatments relative to the no-nematode control, but P. thornei affected expression to a greater extent compared to P. neglectus. The species combination induced the highest number of defense genes. This result was not predicted from nematode enumeration studies, in which P. thornei colonization was substantially lower than that of P. neglectus, and the nematode combination did not show a significant difference. Quantitative real time polymerase chain reaction (qRT-PCR) assays for Dehydrin2, Glucan endo-1,3-beta-glucosidase, 1-cys-Peroxiredoxin, Pathogenesis-related protein 1 and Late embryogenesis-abundant proteins 76 and group 3 authenticated the induction observed in the transcriptome data. In addition, a near-isogenic line of Scarlet harboring genetic resistance to fungal soilborne pathogens, called Scarlet-Rz1, showed similar or higher levels of defense gene expression compared to fungus-susceptible Scarlet in qRT-PCR assays. Finally, transcriptome expression patterns revealed nematode-inducible promoters that are responsive to both P. neglectus and P. thornei. [ABSTRACT FROM AUTHOR]

Microbial and microeukaryotic communities are extremely abundant and diverse in soil habitats where they play critical roles in ecosystem functioning and services that are essential to soil health. Soil biodiversity is influenced by above‐ground (vegetation) and below‐ground factors (soil properties), which together create habitat‐specific conditions. However, the compound effects of vegetation and soil properties on soil communities are less studied or often focused on one component of the soil biota. Here, we integrate metabarcoding (16S and 18S rRNA genes) and nematode morphology to assess the effects of habitat and soil properties shaping microbial and microeukaryotic communities as well as nematode‐associated microbiomes. We show that both vegetation and soil properties (soil bulk density) were major factors structuring microbial and microeukaryotic communities in semi‐arid soil habitats. Despite having lower nutrients and lower pH, denser soils displayed significantly higher alpha diversity than less dense soils across datasets. Nematode‐associated microbiomes have lower microbial diversity, strongly differ from soil microbes and are more likely to respond to microscale variations among samples than to vegetation or soil bulk density. Consequently, different nematode lineages and trophic groups are likely to display similar associated microbiomes when sharing the same microhabitat. Different microbiome taxa were enriched within specific nematode lineages (e.g. Mycobacterium, Candidatus Cardinium) highlighting potentially new species‐specific associations that may confer benefits to their soil nematode hosts. Our findings highlight the importance of exploring above‐ and below‐ground effects to assess community structure in terrestrial habitats, and how fine‐scale analyses are critical for understanding patterns of host‐associated microbiomes. [ABSTRACT FROM AUTHOR]

The nematode Caenorhabditis elegans is well known for its ability to support forward genetic screens to identify molecules involved in neuronal viability and signaling. The proteins involved in C. elegans dopamine (DA) regulation are highly conserved across evolution, with prior work demonstrating that the model can serve as an efficient platform to identify novel genes involved in disease‐associated processes. To identify novel players in DA signaling, we took advantage of a recently developed library of pre‐sequenced mutant nematodes arising from the million mutation project (MMP) to identify strains that display the DA‐dependent swimming‐induced‐paralysis phenotype (Swip). Our screen identified novel mutations in the dopamine transporter encoding gene dat‐1, whose loss was previously used to identify the Swip phenotype, as well as multiple genes with previously unknown connections to DA signaling. Here, we present our isolation and characterization of one of these genes, bbs‐1, previously linked to the function of primary cilia in worms and higher organisms, including humans, and where loss‐of‐function mutations result in a human disorder known as Bardet–Biedl syndrome. Our studies of C. elegans BBS‐1 protein, as well as other proteins that are known to be assembled into a higher order complex (the BBSome) reveal that functional or structural disruption of this complex leads to exaggerated C. elegans DA signaling to produce Swip via a cell‐autonomous mechanism. We provide evidence that not only does the proper function of cilia in C. elegans DA neurons support normal swimming behavior, but also that bbs‐1 maintains normal levels of DAT‐1 trafficking or function via a RHO‐1 and SWIP‐13/MAPK‐15 dependent pathway where mutants may contribute to Swip independent of altered ciliary function. Together, these studies demonstrate novel contributors to DA neuron function in the worm and demonstrate the utility and efficiency of forward genetic screens using the MMP library. [ABSTRACT FROM AUTHOR]

This work evaluates the community of soil nematodes in agricultural and livestock environments with different intensity of land use in the southeast of the province of Buenos Aires. Nematodes were extracted from sites with different intensity of land use: corn (2 consecutive years of conventional tillage [LC]), potato (1 year of LC), soybean (direct seeding), and pastures (with grazing animals). 44 genera of nematodes belonging to 5 trophic groups were identified. The most abundant genera were Helicotylenchus, Pratylenchus and Cruznema. Significant differences were found in the structure of the nematode community between land uses. The total abundance and by trophic groups was higher in soybeans and pasture. Furthermore, in relation to the composition of the community of free-living nematodes (bacteriophages, frugivores, omnivores and predators), the sites with corn and soybeans presented a higher proportion of fungivores, while the sites with potatoes and grass showed a higher proportion of bacteriophages. In relation to phytophagous nematodes, the community associated with sites with greater agricultural disturbance (corn and potatoes) presented a different and less diverse assembly than those associated with sites with less disturbance (soybean and pasture). The nematological indices showed that the successional dynamics of the nematode communities were affected due to land use practices. This was confirmed through the analysis of the faunal profile, the majority of food chains, regardless of the type of land use, were affected by agronomic practices showing mature food webs. This work constitutes the first report on the composition of soil nematode communities in agricultural and livestock production fields in southeastern Buenos Aires, and contributes to understanding the ecology of soil nematode communities impacted by different anthropogenic practices. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) encompass a diverse array of membrane-bound organelles released outside cells in response to developmental and physiological cell needs. EVs play important roles in remodeling the shape and content of differentiating cells and can rescue damaged cells from toxic or dysfunctional content. EVs can send signals and transfer metabolites between tissues and organisms to regulate development, respond to stress or tissue damage, or alter mating behaviors. While many EV functions have been uncovered by characterizing ex vivo EVs isolated from body fluids and cultured cells, research using the nematode Caenorhabditis elegans has provided insights into the in vivo functions, biogenesis, and uptake pathways. The C. elegans EV field has also developed methods to analyze endogenous EVs within the organismal context of development and adult physiology in free-living, behaving animals. In this review, we summarize major themes that have emerged for C. elegans EVs and their relevance to human health and disease. We also highlight the diversity of biogenesis mechanisms, locations, and functions of worm EVs and discuss open questions and unexplored topics tenable in C. elegans , given the nematode model is ideal for light and electron microscopy, genetic screens, genome engineering, and high-throughput omics. [ABSTRACT FROM AUTHOR]

Apical extracellular matrices (aECMs) coat the exposed surfaces of animal bodies to shape tissues, influence social interactions, and protect against pathogens and other environmental challenges. In the nematode Caenorhabditis elegans , collagenous cuticle and zona pellucida protein-rich precuticle aECMs alternately coat external epithelia across the molt cycle and play many important roles in the worm's development, behavior, and physiology. Both these types of aECMs contain many matrix proteins related to those in vertebrates, as well as some that are nematode-specific. Extensive differences observed among tissues and life stages demonstrate that aECMs are a major feature of epithelial cell identity. In addition to forming discrete layers, some cuticle components assemble into complex substructures such as ridges, furrows, and nanoscale pillars. The epidermis and cuticle are mechanically linked, allowing the epidermis to sense cuticle damage and induce protective innate immune and stress responses. The C. elegans model, with its optical transparency, facilitates the study of aECM cell biology and structure/function relationships and all the myriad ways by which aECM can influence an organism. [ABSTRACT FROM AUTHOR]

Arthrobotrys oligospora is a nematode-trapping fungus belonging to the family Orbiliaceae and one of the main antagonists of nematodes in soil, including plant and animal parasitic nematodes and free-living nematodes. This species develops three-dimensional adhesive nets in which nematodes are trapped, destroyed and consumed by the fungus. It also possesses other strategies to immobilise, kill and degrade nematodes, i.e. nematode-attractant substances, cuticle adhesion polymers and a number of nematocidal metabolites. The objective of this study was to assess the in vitro nematocidal activity of a strain of A. oligospora through its predatory activity and its liquid culture filtrates (LCF) against the ruminant parasite Haemonchus contortus (HcL3) and to investigate the presence of myco-compounds with potential nematocidal activity. Predatory activity (PA) was assessed in agar plates; 200 HcL3 were placed on agar plates with the fungus and a control group and incubated for 10 days. The LCF confrontation with nematodes was performed in microtiter plates. Two media, Czapek-Dox Broth (Cz-DB) and potato dextrose broth, were assessed. Three concentrations (25, 50 and 100 mg/mL) were assessed at 48 and 72 h (n = 4, per concentration). The experiment was performed in triplicate. The results showed 73.6 ± 2.7% PA and the highest mortality (83%) with the LCF in Cz-DB after 72 h. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that the A. oligospora ethyl acetate phase was composed of 1,2-benzenedicarboxylic acid, bis (2-methylpropyl) ester, (M) 1,4-benzenedicarboxylic acid, bis (2-methylpropyl) ester and (M) decanedioic acid (2-ethylexyl) ester. These compounds could be responsible for nematocidal activity. [ABSTRACT FROM AUTHOR]

The nematode community was studied at eight stations in the eastern part of the East Siberian Sea shelf (43 m), along the slope, and at a deep-sea site (1350 m). All samples (depth range 43–1350 m) were collected with a MUC corer in the northeastern part of the East Siberian Sea during cruise ARA10C of the R/V Araon in 2019. The taxonomic composition of the nematode community is typical of the Siberian Arctic seas in summer–autumn. The nematode diversity of the East Siberian Sea is poor in comparison with other Russian Arctic seas. Nematode genera typical of the shelf and deep sea were identified. The nematodes density in the uppermost sediment layer increases from the southernmost station along the shelf, amount a maximum on the outer shelf, and decreases downhill with the minimum at the deepest site. It is suggested that the high nematode abundance and diversity on the outer slope was provided by high organic matter fluxes at the boundary of water masses, increasing the oxygen and silt content in sediments. [ABSTRACT FROM AUTHOR]

Meiobenthic samples collected on the Côn Đảo archipelago (Vietnam) from two biotopes, in mangroves and on the adjacent reef flat areas, are analyzed. Quantitative characteristics of the dominant groups of meiobenthos are presented, and taxonomic composition of dominant taxa, nematodes, and harpacticoid copepods, are analyzed. It is shown that analysis of species composition is uninformative for a high species richness and a large number of unique species in each sample. It is more informative to use the generalized characteristics of communities, such as spectra of families and ecological and morphological groups of species. At the level of families and subfamilies, there are well-defined differences in the population of the sandy bottom and mangroves. The proportion of life forms in the different biotypes is informative for harpacticoid copepods. Big differences in the taxonomic composition of the studied bays are shown, interbiotopic differences make a smaller contribution to the overall diversity; i.e., each bay has its own set of species, which forms the population of each biotope. Nematodes and harpacticoids are distributed in space independently of each other. [ABSTRACT FROM AUTHOR]

The article describes the results of studies of two main components of meiobenthos—nematodes and harpacticoid copepods—conducted in Blagopoluchiya Bay (Novaya Zemlya, Kara Sea) in 2013 and 2020. The mosaic distribution of these two taxonomic groups was due to high species diversity and low occurrence of most species. Nevertheless, the authors identified patterns in the changes in the species structure of both groups related to the effect of two main environmental gradients (a spatial gradient related to the distance from the bay mouth to the sea and a depth-related gradient), as well as to the patchiness of sediment distribution. In 7 years between the two surveys in Blagopoluchiya Bay the abundance of nematodes increased tenfold, the copepod abundance also increased, but to a much lesser extent. Taxonomic changes in these two groups were observed at both species and family levels, with no differences in the taxa functional structure. The observed changes can be related to changes in abiotic factors and to general changes in the trophic system of the bay due to the establishment of the snow crab Chionoecetes opilio. [ABSTRACT FROM AUTHOR]

Litylenchus crenatae mccannii is a foliar nematode that causes severe damage to beech, known as beech leaf disease (BLD). Previous studies have characterized and identified L. crenataein Japan and a subspecies L. crenatae mccannii in the USA. Litylenchus crenatae mccannii has been found to cause BLD in native and non-native beech hosts in North America. As little is known about the distribution and diversity of the nematode in Ontario, Canada, beech foliage was sampled throughout southcentral Ontario. Incidence and severity maps show that BLD spread from its first detections in 2017, in Elgin and Norfolk counties, to the west and northeast. A gradient in severity and incidence was observed with the highest ratings at the locations where it was originally found. The extent of the nematode's distribution is much broader than BLD, occurring throughout much of the range of American beech. Sequences of two barcoding loci for the L. crenatae mccannii isolates from 11 locations in Ontario showed 100% similarity within and among these locations. The genotype of L. crenatae mccannii found in Ontario is the same as that identified in the USA. This finding is consistent with the fact that 92% of beech imported into Canada is from the USA and suggests that the USA could be the origin of L. crenatae mccannii nematodes in Ontario or that both countries have imported beech trees from the same source country of BLD. This research provides motivation for further studies to clarify the sources of L. crenatae mccannii. [ABSTRACT FROM AUTHOR]

Civilian and military activities are sources of water and soil contamination by inorganic and organic contaminants caused by shooting practices, warfare, and/or mechanized military training. Lead poisoning and contaminant bioaccumulation due to spent shots or other related military contaminants have been widely studied for mammals, birds, and plants. Although there are different papers on the impact on earthworms, information on micro and mesofauna (i.e., collembola, nematodes, etc.) is still scarce. Here, we review the published data regarding the impact of civilian and military shooting activities, including war-impacted areas, focusing on soil organisms, from microbial communities to the ecotoxicological effects on terrestrial organisms. One hundred eleven studies were considered where earthworms and enchytraeids were widely studied, especially under ecotoxicological assays with Pb and energetic-related compounds from military explosives. There is a lack of information on soil organism groups, such as mites, ants, or gastropods, which play important roles in soil function. Data from combined exposures (e.g., PTEs + TNT and PTEs + PAHs) is scarce since several studies focused on a single contaminant, usually Pb, when combined contaminants would be more realistic. Ecotoxicological assays should also cover other understudied ammunition elements, such as Bi, Cu, or W. [ABSTRACT FROM AUTHOR]

Nematodes typically comprise the most abundant phylum in meiofaunal communities. We aim to characterize the specific ecological conditions that influence Nematoda communities in Posidonia oceanica grasslands focusing on three habitats: leaves, matte, and unvegetated adjacent sediment. We hypothesized that the constant flux of nutrients under the canopy would result in a higher concentration of metazoans compared to the unvegetated sediment outside; however, the hypothesis was not confirmed by the obtained results. The habitat heterogeneity played an important role in shaping the community, yielding a greater richness in the matte. The resource specificity of the leaves (microepiphytes) was also expected to shape the community by favoring nematodes capable of exploiting this resource (epistratum feeders with scraping-like structures), such as the family Chromadoridae that dominated this habitat. In addition, the high light exposure of the leaves explains the higher concentration of ocellated nematodes in this habitat. Organic carbon and nitrogen contents had an impact on the Nematoda community composition, meanwhile average grain size only affected the abundance of nematodes with elongated/filiform tails. [ABSTRACT FROM AUTHOR]

Summary: Brassica plants naturally produce glucosinolates as secondary metabolites hydrolysed to biocidal isothiocyanates (ITCs). As such, they have the potential for nematode management through a strategy known as biofumigation. Pratylenchus penetrans causes significant yield losses in many important crops. Understanding the relative impact of different ITCs on the motility and mortality of this nematode species could provide some insights into the selection of relevant brassica biofumigants. The effects of 3.125, 6.25, 12.5, 25, and 50 μ g ml−1 of pure Allyl, 2-Phenylethyl and Benzyl ITCs on the motility and mortality of P. penetrans were evaluated in laboratory in vitro assays. Motility was assessed after incubating the nematodes in ITCs for 24, 48 and 72 h with distilled water as a negative control. Motile and non-motile nematodes were counted. After motility assessment at 72 h, nematodes were rinsed and incubated in water for 48 h, after which live and dead nematodes were counted. Nematodes were considered dead if they remained non-motile after probing with a picking needle. Nematode motility and mortality were significantly affected by the type of ITC, concentration and time of exposure. The number of non-motile nematodes increased with increasing concentration and time of exposure across all tested ITCs. The ED50 values (concentration required to cause 50% non-motility) of Allyl, 2-Phenylethyl and Benzyl were 37.4, 12.8 and 8.6 μ g ml−1 after 24 h exposure. The ITC with potentially the greatest nematicidal effect was Benzyl (LD50 = 3.2 μ g ml−1), followed by 2-Phenylethyl (LD50 = 5.2 μ g ml−1), and Allyl (LD50 = 9.9 μ g ml−1). The LD50 of all ITCs were not different from the ED50 after 72 h, meaning the effects of ITCs could be considered irreversible. This study suggests that brassica biofumigants that produce Benzyl, Allyl and 2-Phenylethyl ITCs are promising candidates for biofumigation of P. penetrans. [ABSTRACT FROM AUTHOR]

This trial evaluated the production performance, gastrointestinal nematode infection (GIN), and selected blood analytes, in Corriedale lambs during the finishing phase in an integrated crop-livestock system (ICLS) with 2 stocking rates. Fifty-two Corriedale lambs were divided into 4 groups: a semi confinement system with a low stocking rate (T1) for 70 days; a semi confinement system with a high stocking rate (T2) for 70 days; confinement for 28 days, followed by semi confinement with a low stocking rate (T3) for 42 days; and confinement for 28 days, followed by semi confinement with a high stocking rate (T4) for 42 days. Body weight, dry matter intake, blood collection, and faecal analysis of nematode eggs were performed for each animal. The stocking rates did not influence body weight gain for the semiconfined lambs (T1 and T2) or for the confined/semiconfined lambs (T3 and T4). All treatments had lower EPG counts at the end of the experimental period. The nematode genera identified during the experiment trial were Haemonchus and Trichostrongylus. There were no significant differences (P > 0.05) for packed cell volume, total plasma protein, and eosinophil means between treatments. These results suggested that the confinement followed by semi confinement in an ICLS, was an option for lamb production during the finishing phase which could be useful in reducing GIN without affecting the production performance. [ABSTRACT FROM AUTHOR]

The ubiquitin-proteasome system (UPS) is critical for maintaining proteostasis, influencing stress resilience, lifespan, and thermal adaptability in organisms. In Caenorhabditis elegans, specific proteasome subunits and activators, such as RPN-6, PBS-6, and PSME-3, are associated with heat resistance, survival at cold (4°C), and enhanced longevity at moderate temperatures (15°C). Previously linked to improving proteostasis, we investigated the impact of sterility-inducing floxuridine (FUdR) on UPS functionality under proteasome dysfunction and its potential to improve cold survival. Our findings reveal that FUdR significantly enhances UPS activity and resilience during proteasome inhibition or subunit deficiency, supporting worms' normal lifespan and adaptation to cold. Importantly, FUdR effect on UPS activity occurs independently of major proteostasis regulators and does not rely on the germ cells proliferation or spermatogenesis. Instead, FUdR activates a distinct detoxification pathway that supports UPS function, with GST-24 appearing to be one of the factors contributing to the enhanced activity of the UPS upon knockdown of the SKN-1-mediated proteasome surveillance pathway. Our study highlights FUdR unique role in the UPS modulation and its crucial contribution to enhancing survival under low-temperature stress, providing new insights into its mechanisms of action and potential therapeutic applications. Author summary: In our study, we investigate the ubiquitin-proteasome system (UPS) in Caenorhabditis elegans, a crucial cellular machinery for degrading and recycling misfolded or excess proteins. The efficiency of this system is vital for cell health, particularly under stress conditions such as cold. We found that floxuridine (FUdR), commonly used to induce sterility in nematodes, also triggers an alternative UPS-stimulating or UPS-relieving pathway. This supports worms' lifespan and ability to survive at low temperatures (4°C) despite proteasome deficiencies. This enhancement occurs independently of major proteostasis regulators and does not rely on reproductive pathways or conventional stress response mechanisms. Instead, FUdR activates a distinct detoxification pathway that can boost UPS activity, with GST-24 appearing to be one of the contributing factors. Our findings reveal a novel aspect of FUdR action, suggesting potential strategies for enhancing cellular resilience to environmental stress and aging in broader biological contexts. [ABSTRACT FROM AUTHOR]

Parasites negatively affect the fitness of ungulate hosts directly, and in wild ungulates, these effects may be synzootic with other stressors, such as limited nutritional resources. In the Arctic, muskoxen (Ovibos moschatus) occur in a highly seasonal environment and must rely on finite energetic resources for survival and productivity. We investigated the costs of gastrointestinal nematodes on the body condition and reproductive status of 141 muskoxen, on Banks Island, Canada, when the population was at a peak in numbers and density. Using a Partial Least Squares Path Modelling approach, we found that high adult nematode abundance was associated with lower body condition, and high parasite abundance was associated with female reproduction including the indirect effect through on body condition (n = 87). These findings suggest that individuals prioritize energetic reserves for reproduction over parasite defence. In fall 2003, a severe icing event that restricted access to forage was associated with high overwinter mortality of muskoxen and a population crash. Through direct and indirect costs of parasite infection on body condition and reproduction, the high abundance of parasites may have contributed to the effects of this extreme weather event. Understanding the mechanisms in which parasites impact fitness can help explain the ecological drivers of ungulate populations and predict the interactions between the environment and populations. [ABSTRACT FROM AUTHOR]

Plant-parasitic nematodes are a major problem for horticultural production, causing significant economic losses. Chemical nematicides are a common nematode control strategy but can negatively impact the environment and human health. In this review, we provide an overview of the use of fungi for the biological control of plant-parasitic nematodes in horticultural crops. Fungal bio-control represents an alternative, environmentally friendly strategy for managing nematodes. The use of fungi for the bio-control of nematodes has gained increasing attention due to the potential benefits of selectivity, sustainability, and long-term control. Here, we discuss the different types of fungi used for nematode management, the mechanisms of their action, the advantages and limitations of using fungi for bio-control, and the factors affecting their efficacy. Additionally, we provide several case studies of fungal bio-control against root-knot, cyst, and lesion nematodes in horticultural crops. The review concludes with a discussion of future directions and research recommendations for implementing fungal bio-control in horticultural crops. [ABSTRACT FROM AUTHOR]

Background: Plant-parasitic nematodes are economically important pests responsible for substantial losses in agriculture. Researchers focusing on plant-parasitic nematodes, especially on finding new ways of their control, often need to assess basic parameters such as their motility, viability, and reproduction. Traditionally, these assays involve visually counting juveniles and eggs under a dissecting microscope, making this investigation time-consuming and laborious. Results: In this study, we established a procedure to efficiently determine the motility of two plant-parasitic nematode species, Heterodera schachtii and Ditylenchus destructor, using the WMicrotracker ONE platform. Additionally, we demonstrated that hatching of the cyst nematode H. schachtii can be evaluated using both the WMicrotracker ONE and by assessing the enzymatic activity of chitinase produced during hatching. Conclusions: We present fast and straightforward protocols for studying nematode motility and hatching that allow us to draw conclusions about viability and survival. Thus, these methods are useful tools for facilitating fast and efficient evaluation in various fields of research focused on plant-parasitic nematodes. [ABSTRACT FROM AUTHOR]

AbstractPlant-parasitic nematodes (PPNs) pose a significant threat to global agriculture, leading to substantial yield losses. Managing nematode populations remains a challenging option due to financial, technical and environmental constraints. In Ontario, Canada, the presence of Xiphinema nematodes, a virus vector species, is of particular concern. This study reports the discovery of X. diversicaudatum in a peach field in Southern Ontario, Canada. The description includes morphological and molecular characterization using the 18S and 28S rDNA sequences. Morphological and molecular characterization of Ontario’s population matched those from Europe. While X. diversicaudatum was presumed eradicated from Canada, the present finding showed that the nematode could have spread beyond greenhouses. The study highlights the importance of intensive soil sampling for early nematode detection, even as strict reporting requirements may deter such efforts. We report for the first time the presence of X. diversicaudatum on peaches in Canada and in North America. [ABSTRACT FROM AUTHOR]

Currently, it is widely accepted that the type III secretion system (T3SS) serves as the transport platform for bacterial virulence factors, while flagella act as propulsion motors. However, there remains a noticeable dearth of comparative studies elucidating the functional disparities between these two mechanisms. Entomopathogenic nematode symbiotic bacteria (ENS), including Xenorhabdus and Photorhabdus, are Gram-negative bacteria transported into insect hosts by Steinernema or Heterorhabdus. Flagella are conserved in ENS, but the T3SS is only encoded in Photorhabdus. There are few reports on the function of flagella and the T3SS in ENS, and it is not known what role they play in the infection of ENS. Here, we clarified the function of the T3SS and flagella in ENS infection based on flagellar inactivation in X. stockiae (flhDC deletion), T3SS inactivation in P. luminescens (sctV deletion), and the heterologous synthesis of the T3SS of P. luminescens in X. stockiae. Consistent with the previous results, the swarming movement of the ENS and the formation of biofilms are dominated by the flagella. Both the T3SS and flagella facilitate ENS invasion and colonization within host cells, with minimal impact on secondary metabolite formation and secretion. Unexpectedly, a proteomic analysis reveals a negative feedback loop between the flagella/T3SS assembly and the type VI secretion system (T6SS). RT-PCR testing demonstrates the T3SS's inhibition of flagellar assembly, while flagellin expression promotes T3SS assembly. Furthermore, T3SS expression stimulates ribosome-associated protein expression. [ABSTRACT FROM AUTHOR]

In Sub-Saharan Africa, cereals are threatened by stress-inducing microbial pathogens and parasites such as fungi, bacteria, viruses and nematodes leading to significant losses. Mycotoxin-producing fungi like Fusarium graminearum induce head blight disease causing 30–70% of yield losses in wheat. In comparison, Fusarium verticillioides accounts for ear rot diseases that account for 13–70% of maize yield losses in Sub-Saharan Africa. Outbreaks of the devastating rice blast pathogen Magnaporthe oryzae have caused up to 48% yield losses of rice in Kenya. The grey leaf spot fungus, C. zeina, gradually becomes a threat to maize production, causing a 65% yield loss in South Africa. Maize smut and ergot-causing pathogens, Sporisorium ehrenbergii and Claviceps africana, under mildly humid and cold climatic conditions, impact grain quality and market value. The maize streak virus predominantly ravages maize fields all over Sub-Saharan Africa causing 30–100% yield losses while the diseases caused by the bacterium Xanthomonas oryzae pv. oryzae has led to 10 to 50% yield losses in rice production. In Nigeria, nematode pathogens like Pratylenchus spp have been reported to cause yield losses of up to 27% in maize production. This review fundamentally discusses these cereal pathogens and their current and future impact in the face of climate change in Africa. We seriously emphasize the need for more simulation studies on each of these pathogens across Sub-Saharan Africa and their potential impact under current and future climate change scenarios. [ABSTRACT FROM AUTHOR]

The population of South American camelids (SAC) has been steadily growing in Europe, where they are confronted with the regional endoparasite population of ruminants. As there are no anthelmintic drugs registered for use against nematode infections in SACs, anthelmintics (AH) available for ruminants or horses are usually applied. Reports indicating potential failures in administered AH are increasing. However, the generally low egg counts in SACs complicate the application of resistance tests in the field. The present study reports a follow-up study on SAC farms where anthelmintic resistance (AR) was suspected. The aims were (i) to repeat faecal egg count reduction tests (FECRTs) on potentially affected farms identified in a previous study with larger sample sizes, (ii) to verify suspected AR of Haemonchus contortus against benzimidazoles (BZ) by performing a single-nucleotide polymorphism (SNP) analysis using digital polymerase chain reaction (dPCR), and (iii) to apply the mini-FLOTAC technique for more reliable results at low egg counts in line with current recommendations. Seven farms (9–46 animals each) were examined by coproscopy, larval differentiation and SNP analysis. A FECRT was performed on six of these farms with moxidectin (three farms), monepantel (two farms) and ivermectin (one farm). The FEC was calculated according to the current World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines with the clinical protocol (a newly introduced variant of FECRT which can be used for smaller sample sizes and lower egg counts on the cost of sensitivity) and an expected efficacy of 99%. A high level (> 90%) of BZ-resistance-associated SNPs on codon 200 of H. contortus was observed on all farms. With the FECRT, resistance was demonstrated for ivermectin (74% FECR), while it remained inconclusive for one farm for moxidectin treatment. Sustained efficacy was demonstrated for the remaining treatments. This study showed an advanced level of BZ resistance in H. contortus of SACs and the development of AR against macrocyclic lactones on some farms. Thus, constant monitoring of AH treatment and sustainable worm control methods both need to be applied. [ABSTRACT FROM AUTHOR]

Monochamus alternatus is one of the most important borers of conifers and the main vector of the pinewood nematode, Bursaphelenchus xylophilus, the causal agent of pine wilt disease. It causes massive death of pine trees and seriously affects the health of forest ecosystems. Traditionally, adults or larvae are identified by morphological or molecular methods. However, diagnosing M. alternatus larvae at different instars collected from forests is expensive and time‐consuming. Non‐destructive molecular diagnostic protocols are, therefore, being developed to detect biological traces (i.e. exuviae, excreta) and to determine the distribution and spread of this pest. In this study, based on the alignment of mitochondrial DNA cytochrome oxidase subunit I (COI) gene sequences of M. alternatus and other insect species, we designed the primer pair of Mal‐SF/Mal‐SR and probe of Mal‐P for M. alternatus. TaqMan probe‐based qPCR was developed to identify the occurrence of M. alternatus in forests by amplifying the DNA samples obtained from its adult, larva, frass, excreta and exuviae. The amplification results were very effective. The lowest amount of M. alternatus DNA that could be detected with a Cq of 31.93 in the mixed samples was 0.64 pg, showing very high sensitivity. This assay can easily identify M. alternatus from other non‐target wood‐borer species using its frass and exuviae, providing a new diagnostic protocol for monitoring the occurrence and distribution of M. alternatus in forests. [ABSTRACT FROM AUTHOR]

Eustrongylides excisus is a fish-borne zoonotic parasite known to infect various fish species, including Northern pike (Esox Lucius). This nematode, belonging to the family Dioctophymatidae, has a complex life cycle involving multiple hosts. This study aimed to investigate the occurrence of Eustrongylides nematodes in Northern pike (E. Lucius) collected from Mijran Dam (Ramsar, Iran). Between June and October 2023, an investigation was conducted on Northern pike from Mijran Dam in Ramsar, Iran, following reports of reddish parasites in their muscle tissues. Sixty fish were examined at the University of Tehran, revealing live parasites in the muscles, which were then analyzed microscopically and preserved for a multidisciplinary study. The skeletal muscle tissues of 85% (51/60) of fish specimens were infected by grossly visible larvae which were microscopically identified as Eustrongylides spp. In histopathological examination, the lesion was composed of encapsulated parasitic granulomatous myositis. Microscopically, the cystic parasitic granulomas compressed the adjacent muscle fibers, leading to their atrophy and Zenker's necrosis. Moreover, epithelioid macrophages, giant cells and mononuclear inflammatory cells were present around the larvae and between the muscle fibers. Finally, a molecular analysis by examining the ITS gene region, revealed that they belong to the species E. excisus. Eustrongylidiasis in northern Iran necessitates further research into the biology, epidemiology, and control of Eustrongylides nematodes, focusing on various hosts. This study is the first to comprehensively characterize E. excisus in Northern pike in Ramsar, Iran, raising concerns about possible zoonotic transmission. [ABSTRACT FROM AUTHOR]

Human dirofilariasis is a rare anthropo-zoonotic disease, mainly detected in Southern and Eastern Europe, Asia Minor, Central Asia, and Sri Lanka. An increasing number of autochthonous Dirofilaria spp. infections has been recently reported in the areas previously considered free of the disease, including northern Europe and the Baltic States. A rare autochthonous case of scrotal dirofilariasis detected in Lithuania was described. Here, a 42-year-old male presented with a 1 cm nodule, limited in the scrotum. A nodule excision was performed. On histological examination, a degenerating roundworm with the features of Dirofilaria spp. (multilayered cuticle, well-developed musculature, focally preserved longitudinal ridges) was detected in the abscess cavity. No additional treatment was needed. Twenty-four publications reporting 28 male genitalia dirofilariasis cases in European countries have been identified. [ABSTRACT FROM AUTHOR]

A prospective study was conducted from September 2022 to March 2023 to examine the occurrence and contamination rates of different parasitic stages on fresh edible fruits and vegetables in local markets of Erbil city. Eight different types of fruits and vegetables were selected from eight markets, and 144 samples were analyzed for parasites using direct sedimentation, indirect floatation (ZnSO4), Kinyoun, and trichrome staining methods. The highest total frequencies of parasites were detected using the direct sedimentation method (18.75%), followed by the indirect floatation method (6.25%), Kinyoun technique (5.55%), and modified trichrome staining (4.16%). A. lumbricoides (Ova) was detected with 4.16% using direct sedimentation, while no positive detections were observed with other techniques. Kinyoun technique identified Cryptosporidium spp. oocysts. For E. histolytica 1.3% were positive using the direct sedimentation method, while the other three methods showed no positive detections. Similar results were observed for G. lamblia where only the modified trichrome staining technique detected 0.69% with trophozoites and 1.3% with cysts. Additionally, the direct sedimentation method revealed the presence of nematodes at 2.77%, but no positive detections were made with other methods. Concerning Taeniid eggs, the indirect floatation identified 0.69% with ova, while other methods showed no positive detections. Lastly, the direct sedimentation method yielded 6.25% with unidentified flagellate protozoa, but no positive detections were found using the indirect floatation method, Kinyoun technique, or modified trichrome staining technique. The study concluded that Kinyoun and trichrome techniques are the gold standard for detecting different parasite stages. [ABSTRACT FROM AUTHOR]

The study was conducted during the period 2019-2021 under field conditions and artificial infection with Aphelenchoides besseyi Christie (rice white tip nematode). Four varieties and two lines of rice were tested. The lowest percentage of plants showing symptoms of „white tip” is the variety CRLB 1. The variety Cameo is highly susceptible to infection with a higher number of nematodes in the seeds. Artificial infection leads to a decrease in the values of the panicle length, the total number of grains per panicle, the weight of one panicle, the weight of the grain in a panicle and the weight of 1000 grains in plants showing symptoms. In the varieties Osmanchik 97, Cameo and line No 19 a larger decrease in the yield by elements was found. [ABSTRACT FROM AUTHOR]

In the context of climate warming, the intensity and frequency of drought occurrences are progressively increasing. However, current research on the impacts of drought on the life-history traits and physiological activities of animals rarely encompasses soil animals that play crucial roles within soil ecosystems. Therefore, this study focused on a soil nematode species (Acrobeloides sp.) and a model nematode (Caenorhabditis elegans) to investigate whether nematodes adjust the trade-off of their life-history traits to confront arid environments, utilizing a Petri dish experiment. Subsequently, we assessed the resilience of the two nematode species to moisture variations by comparing the extent of changes in various indicators (i.e. life-history traits, physiological traits, and oxidative stress) of nematodes before and after drought and rehydration. The results revealed that both nematode species are capable of adapting to arid environments by altering the trade-off between life-history traits. Specifically, they reduce reproductive investment and body mass while maintaining life span, thus responding to drought conditions. Follow-up rehydration experiments post-drought stress highlighted that the soil-dwelling nematode exhibits a superior recovery capacity in response to moisture fluctuations in comparison to the model nematode. To the best of our knowledge, this is the first investigation into life history of drought adaptation within soil-dwelling nematodes. Moreover, the findings hold significant implications for the exploration of drought adaptation and its mechanisms in soil-dwelling animals. [ABSTRACT FROM AUTHOR]

Fungi are a source of a variety of secondary metabolites of importance in different areas of biotechnology. Several compounds have been characterized with antioxidant, antimicrobial, and anti-inflammatory activity from fungi of the division of the Ascomycota, among which is the species Daldinia eschscholtzii, an endophyte fungus of pantropical distribution. In this study, we evaluated the effect of an ointment made with D. eschscholtzii on the wound healing of BALB/c mice. The species was corroborated using a molecular marker Internal Transcribed Spacer (ITS1 and ITS4). The extracts and dust of the fungus were considered nontoxic as they caused a mortality of <15% in the nematode Panagrellus redivivus, and experimental ointments had no adverse effects on the skin of BALB/c mice. Wounds treated with the D. eschscholtzii ointments had 99.9–100% wound contraction after 17 days, which was similar to commercial healing (positive control). As such, the ointment of D. eschscholtzii is a natural alternative to improve wound healing. [ABSTRACT FROM AUTHOR]

In the present work, laboratory assays were performed to appraise the biocontrol potential of Metarhabditis amsactae, a Rhabditid nematode, against fifth instar larvae of Corcyra cephalonica. Virulence was tested at four different doses, i.e. 20, 40, 80 and 160 IJs/L (infective juveniles per larva) and mortality was documented from 24 up to 96 h of nematode treatment. Concentration and time-based enhancement in larval mortality was observed with 100% mortality recorded at 160 IJs/L after 96 h. Even at 20 IJs/L concentration, 60% and 76.7% larval mortality was recorded after 72 and 96 h, respectively. At 80 IJs/L, the mortality increased from 33.3% at 48 h to more than 90% at 96 h of nematode inoculation. Whereas, at 40 IJs/L, it enhanced from 16.7% at 48 h to 83.3% at 96 h. The effect of M. amsactae infection on the immune system of C. cephalonica was also evaluated at a dose of 100 IJs/L after 12, 24, 36 and 48 h time intervals. Insect larvae displayed augmented levels of antioxidant and detoxifying enzymes. The peak activities of superoxide dismutase, catalase, ascorbate peroxidase, phenol oxidase and glutathione-S-transferase in infected larvae were observed after 36 h, whereas acetylcholine esterase levels peaked after 48 h, as compared to control. Malondialdehyde content was also increased post nematode infection. Thus the current study is the first report that depicts the significant bioefficacy and immunomodulatory effects of M. amsactae against C. cephalonica under laboratory conditions. However, further research to assess its efficiency under field conditions is required. [ABSTRACT FROM AUTHOR]

Emerging knowledge of plant–soil biotic interactions and the role of soil organisms in shaping the world aboveground is advancing our understanding of ecosystem function. Nematodes are the most abundant animals on Earth. They are morphologically and functionally diverse, and play key roles in ecosystem function, making them ideal for developing a trait-based understanding of adaptation to the environment and for assessing their contributions to ecosystem function. Trait-based approaches allow us to capture the functional attributes of organisms beyond their taxonomic identity, provide insights on evolutionary fitness, and make global comparisons possible. We propose the nematode economics spectrum (NES), analogous to the plant economic spectrum, which describes the tradeoffs among growth, reproduction, and survival, potentially enabling us to predict the impacts of global change on nematode ecological strategies and the associated changes in ecosystem function. Trait-based approaches are being increasingly adopted to understand species' ecological strategies and how organisms influence ecosystem function. Trait-based research on soil organisms, however, remains poorly developed compared with that for plants. The abundant and diverse soil nematodes are prime candidates to advance trait-based approaches belowground, but a unified trait framework to describe nematode ecological strategies and assess their linkages with ecosystem function is lacking. We categorized nematode traits as morphological, physiological, life history, and community clusters, and proposed the nematode economics spectrum (NES) to better understand nematode ecological strategies and their association with ecosystem function. We argue that bridging the NES and the plant economics spectrum will facilitate a more holistic understanding of ecosystem carbon and nutrient cycling under global change. [ABSTRACT FROM AUTHOR]

Summary statement: We propose exploring plant biotrophic parasitism from both a pathogen‐centred and a plant‐centred perspective. This can generate novel research questions and reveal common plant mitigation strategies in response to biotrophic pathogens. [ABSTRACT FROM AUTHOR]

On pasture, sheep are exposed to infections with gastrointestinal nematodes. Infections with gastrointestinal nematodes cause damage to the animal and also have economic relevance. In order to avoid an excessive parasite load in the animal and to treat parasitosis, anthelmintics are used for deworming. However, gastrointestinal nematodes are becoming increasingly resistant to anthelmintics, making treatment less and less effective. Accordingly, alternative strategies are required to combat gastrointestinal nematodes. Breeding sheep with increased immunocompetence against gastrointestinal nematodes is a sustainable and long-term strategy. In order to proceed responsibly and effectively, the complexity of infections with gastrointestinal nematodes must be considered in more detail. This review article therefore deals with the infection, the effects of the infection on the animal, the immunological response shown by the animal, the acquired immunity to gastrointestinal nematodes as well as with parasite-host interactions. The article refers to the situation in Germany and concludes with a summary of the need for national action. [ABSTRACT FROM AUTHOR]

The aim of the present study was to determine the prevalence and severity of root-knot nematodes in peach orchards in the Pothwar Region of Pakistan. Thirty-seven peach orchards were surveyed in the region and root and soil samples were collected from 10 randomly selected plants in each orchard for analysis. In the region, an overall incidence rate of 19.8% and a prevalence rate of 65.7% of root-knot nematodes were observed. The district Attock exhibited the highest prevalence rate of 71.43% and incidence rate of 34.29%. Conversely, the district Islamabad displayed the lowest prevalence rate of 50.5% and incidence rate of 10%. The surveys encountered five distinct peach varieties, and Early Grand had the highest prevalence (85.71%) of root-knot nematodes while Local Aroo showed the lowest (50%). Florida Gold and Aroo-5 were not infested with root-knot nematodes. In the region, peach trees were found to be infected by two types of root-knot nematodes, namely, Meloidogyne incognita and M. javanica., which was more prevalent than M. incognita, and it dominated all districts, except for Attock, where M. incognita was dominant. M. incognita was not present in Islamabad district. The occurrence of M. incognita and M. javanica as single populations were observed in 26.09 and 43.48% of orchards, respectively, while mixed populations were found in 30.43% of peach orchards. The overall galling index of the root-knot nematodes was 1.33, with the highest index in Attock and the lowest in Islamabad districts. Among the different peach cultivars, the Early Grand cultivar exhibited the maximum galling index, whereas no galling index was observed in the Florida Gold and Aroo-5 cultivars. It is recommended that stringent control strategies should be adopted to prevent the spread of nematodes to new plantations and to eradicate them from established orchards. [ABSTRACT FROM AUTHOR]

In order to know whether there is a risk of anisakiasis (or anisakidosis) by consumption of fish of the genus Mullus from the western Mediterranean Sea, which are appreciated for their quality, an epidemiological survey was carried out to evaluate the occurrence of zoonotic or potentially zoonotic nematodes in M. barbatus and M. surmuletus. Although the presence of the third larval stage (L3) of anisakids (Anisakis and Contracaecum) has been previously described in these fish, the results showed the absence of anisakids and the presence, never in muscle, of L3 and L4 of raphidascaridids of the genus Hysterothylacium, molecularly identified as H. fabri. Phylogenetic analysis groups them into the Mediterranean Sea clade, far from individuals isolated in the Pacific Ocean. Prevalence was slightly higher, but not significant, in M. barbatus versus M. surmuletus (72.3% vs 60.0%), but mean intensity (MI) and mean abundance (MA) parameters were approximately twice as high in M. barbatus as in M. surmuletus (MI 5.8 vs 2.8, p = .001; MA 4.2 vs 1.7, p < .001). The presence of the parasite seems to have different effects on these two sympatric species. In M. barbatus it seems to affect their growth, as it appreciably reduces the value of allometry coefficient in infected fish (2.78 vs. 2.18). On the other hand, in M. surmuletus the infection significantly (p < .04) affects the Fulton's condition factor, an indicator of the health status of the fish. It can be concluded that the ingestion of these fish by the people poses negligible risk of anisakiasis, but the consumer should continue to be urged to follow the rules of prevention against this illness. [ABSTRACT FROM AUTHOR]

Summary: The genus Oscheius includes species with different habits and some of them have been shown to kill some insect pests. The occurrence of Oscheius in hay meadow soils from the area recently invaded by the Japanese beetle Popillia japonica in Lombardy, Italy, has been surveyed. Oscheius myriophilus was detected at five out of 18 sites resulting positive to entomopathogenic nematodes (EPN), either alone or together with other genera of EPN, indicating a widespread occurrence. The morphological analysis of the strains retrieved showed that they are morphologically in agreement with those of the type population and with other populations recently described. The phylogenetic analysis supported the sub-grouping of all sequences of O. myriophilus from Lombardy with those present in the databases and a close relationship with O. safricana was observed. The capacity to kill the laboratory host Galleria mellonella was similar to that observed in a previous study related to isolates from P. japonica , although O. myriophilus did not cause significant mortality in laboratory trials with the invasive beetles. The isolates of O. myriophilus from Lombardy were characterised in relation to their infectivity to G. mellonella and response to environmental stress, such as heat tolerance and desiccation. Overall, O. myriophilus appears to be an important component of the EPN community of hay meadow soil in Lombardy and might play a role in the containment of the invasive P. japonica. [ABSTRACT FROM AUTHOR]

Summary: Cryptaphelenchus species are wood- or bark-inhabiting nematodes, generally mycetophagous and reported to have endophoretic associations with insects. In the present study, we describe two new and one known Cryptaphelenchus species detected in imported and domestic wood samples. Cryptaphelenchus americanum n. sp. and C. minutus were detected in the log samples of Pinus taeda imported from the USA, whereas C. orientalis n. sp. was isolated from the bark of dying Pinus sylvestris trees in Inner Mongolia, China. Both new species displayed characteristic features, including a relatively short body length, four lateral lines, a short post-vulval uterine sac in females, and a distinct cloacal apophysis in male tails. Newly recovered and known species were characterised molecularly, and phylogenetic trees were constructed to study their relationship with related Cryptaphelenchus species. Notably, the genetic divergence observed among Cryptaphelenchus species was found to be more significant compared to morphometrical differences, highlighting the importance of molecular data in taxonomy. The identification of new and known species expands our understanding of the genus and suggests that Cryptaphelenchus species may be under studied, underscoring the necessity for continued exploration. [ABSTRACT FROM AUTHOR]

Soybean cyst nematode (SCN), Heterodera glycines, HG type 1.2.5.7 is the most virulent and widespread SCN biotype in the southern states of the USA, but its effect on soybean (Glycine max [L.] Merr.) nitrogen fixation (NF) activity and growth is not well documented. The objectives of this study were to: (1) measure the impact of HG type 1.2.5.7 on NF activity during the early vegetative stage of three soybean genotypes and (2) compare the impact on soybean leaf and root development, and plant growth. The NF activity of two susceptible (S) genotypes ("Ellis" and "Williams 82") and one resistant (R) genotype (PI 88,788), subjected to a 10,000-egg treatment, was measured using an in-situ flow-through acetylene reduction assay. The average NF activity of the soybean genotypes was decreased by SCN activity. Time points assessment showed that the NF activity was differently impacted among the genotypes. Based on the measured values, the NF activity was decreased by 30% in SCN infected plants of Williams 82 but that of PI 88,788 and Ellis was affected. Likewise, soybean leaf color and leaf area were affected by SCN infection, but there was no impact on root length and root area. These results showed that SCN HG type 1.2.5.7 can exhibit varying negative impact on NF and shoot growth of S soybean genotypes, while R genotypes may be unaffected. Thus, indicating genetic resistance continues to be a critical tool for the management of the SCN. [ABSTRACT FROM AUTHOR]

Ticks are ectoparasites responsible for the transmission of various pathogens to vertebrates. They represent one of the major threats to livestock production worldwide due to their impact on the health, production and welfare of livestock destined for human consumption. The development of resistance to the main families of ixodicides used for their control has led to the search for new alternatives, where microbial control is an option. The use of microbial control agents against the tick Rhipicephalus microplus is reviewed in this paper. Bacteria such as Bacillus thuringiensis, Serratia marcescens and Staphylococcus spp. the nematodes Steinernema spp. and Heterorhabditis spp. as well as the fungi Metarhizium anisopliae and Beauveria bassiana are the most studied organisms for use as biological control agents against ticks. Laboratory, stable and field trials with free-living and parasitised ticks have shown that microbial agents can control both susceptible and ixodicide-resistant tick populations. However, multidisciplinary studies using novel tools like genomics, transcriptomics and proteomics should be carried out to understand the virulence factors which microbial agents use to induce pathogenesis and virulence in ticks. In addition, applied research will be carried out with the aim of improving techniques for large-scale application, as well as the improvement of cultivation, storage, formulation and application methods. [ABSTRACT FROM AUTHOR]

We describe a recent case of lymphatic filariasis in Colombia caused by Wuchereria bancrofti nematodes. Our study combines clinical-epidemiologic findings with phylogenetic data. Resurgence of lymphatic filariasis may be linked to increasing urbanization trends and migration from previously endemic regions. Fieldwork can be a beneficial tool for screening and containing transmission. [ABSTRACT FROM AUTHOR]

The objective of this study was to identify genomic regions and genes associated with resistance to gastrointestinal nematodes in Australian Merino sheep in Uruguay, using the single-step GWAS methodology (ssGWAS), which is based on genomic estimated breeding values (GEBVs) obtained from a combination of pedigree, genomic, and phenotypic data. This methodology converts GEBVs into SNP effects. The analysis included 26,638 animals with fecal egg count (FEC) records obtained in two independent parasitic cycles (FEC1 and FEC2) and 1700 50K SNP genotypes. The comparison of genomic regions was based on genetic variances (gVar(%)) explained by non-overlapping regions of 20 SNPs. For FEC1 and FEC2, 18 and 22 genomic windows exceeded the significance threshold (gVar(%) ≥ 0.22%), respectively. The genomic regions with strong associations with FEC1 were located on chromosomes OAR 2, 6, 11, 21, and 25, and for FEC2 on OAR 5, 6, and 11. The proportion of genetic variance attributed to the top windows was 0.83% and 1.9% for FEC1 and FEC2, respectively. The 33 candidate genes shared between the two traits were subjected to enrichment analysis, revealing a marked enrichment in biological processes related to immune system functions. These results contribute to the understanding of the genetics underlying gastrointestinal parasite resistance and its implications for other productive and welfare traits in animal breeding programs. [ABSTRACT FROM AUTHOR]

The ITS‐2‐rRNA has been particularly useful for nematode metabarcoding but does not resolve all phylogenetic relationships, and reference sequences are not available for many nematode species. This is a particular issue when metabarcoding complex communities such as wildlife parasites or terrestrial and aquatic free‐living nematode communities. We have used markerDB to produce four databases of distinct regions of the rRNA cistron: the 18S rRNA gene, the 28S rRNA gene, the ITS‐1 intergenic spacer and the region spanning ITS‐1_5.8S_ITS‐2. These databases comprise 2645, 254, 13,461 and 10,107 unique full‐length sequences representing 1391, 204, 1837 and 1322 nematode species, respectively. The comparative analysis illustrates the complementary value but also reveals a better representation of Clade III, IV and V than Clade I and Clade II nematodes in each case. Although the ITS‐1 database includes the largest number of unique full‐length sequences, the 18S rRNA database provides the widest taxonomic coverage. We also developed PrimerTC, a tool to assess primer sequence conservation across any reference sequence database, and have applied it to evaluate a large number of previously published rRNA cistron primers. We identified sets of primers that currently provide the broadest taxonomic coverage for each rRNA marker across the nematode phylum. These new resources will facilitate more comprehensive metabarcoding of nematode communities using either short‐read or long‐read sequencing platforms. Further, PrimerTC is available as a simple WebApp to guide or assess PCR primer design for any genetic marker and/or taxonomic group beyond the nematode phylum. [ABSTRACT FROM AUTHOR]

Xenorhabdus nematophila is a symbiotic Gammaproteobacterium that produces diverse natural products that facilitate mutualistic and pathogenic interactions in their nematode and insect hosts, respectively. The interplay between X. nematophila secondary metabolism and symbiosis stage is tuned by various global regulators. An example of such a regulator is the LysR-type protein transcription factor LrhA, which regulates amino acid metabolism and is necessary for virulence in insects and normal nematode progeny production. Here, we utilized comparative metabolomics and molecular networking to identify small molecule factors regulated by LrhA and characterized a rare γ-ketoacid (GKA) and two new N-acyl amides, GKA-Arg (1) and GKA-Pro (2) which harbor a γ-keto acyl appendage. A lrhA null mutant produced elevated levels of compound 1 and reduced levels of compound 2 relative to wild type. N-acyl amides 1 and 2 were shown to be selective agonists for the human Gprotein-coupled receptors (GPCRs) C3AR1 and CHRM2, respectively. The CHRM2 agonist 2 deleteriously affected the hatch rate and length of Steinernema nematodes. This work further highlights the utility of exploiting regulators of host-bacteria interactions for the identification of the bioactive small molecule signals that they control. [ABSTRACT FROM AUTHOR]

It is common knowledge that plastic pollution has become one of the foremost environmental problems worldwide. Despite the increasing rates in plastic products recycling, the majority of plastic still finds its way unchecked into the environment. Plastic in itself poses no substantial threat to ecosystems, unlike its degraded components, microplastics (MP) and nanoplastics (NP), which are more reactive and easier to transport due to their reduced size. In recent years, the increasing demand, production, and utilisation of products originally manufactured in the form of MP and NP have further exacerbated the pollution problem. Once released, MPs and NPs tend to accumulate more in terrestrial ecosystems than in aquatic environments, an area that has been researched more comprehensively. Consequently, the degraded components of plastic accumulate within soil-dwelling organisms, which can then further break them down (degrade) through their metabolism. The aim of this study was to provide an overview of the ecotoxicity of MP and NP specifically on earthworms, as representatives of the phylum annelid worm (Annelida), and on nematodes (phylum Nematoda), the two most prevalent groups of soil-dwelling invertebrates. Research into the effects of MP and NP on earthworms has so far been conducted on the species Eisenia fetida, Eisenia andrei, and Lumbricus terrestris, with the species Caenorhabditis elegans serving as a representative nematode species. These organisms were exposed to polyethylene (PE), polystyrene (PS), and polypropylene (PP) particles of varying sizes and concentrations. The results of numerous studies on the harmful effects of these polymeric materials on earthworms and nematodes were measured by testing for inhibition of survival and growth rate, showing significant body weight loss, along with damage to the digestive system, and oxidative stress. [ABSTRACT FROM AUTHOR]

Sediment is the ultimate sink of environmental pollutants. A total of 128 surface sediment samples were collected from 8 rivers and 3 reservoirs in Maoming City, Guangdong Province. This study assessed the content and distribution of brominated flame retardants in sediments. The acute toxicity effects of tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCDs) in sediments were evaluated using Caenorhabditis elegans as model organisms. The concentration of TBBPA in sediments ranged from not detected (ND) to 12.59 µg/kg and was mainly distributed in the central area, which was affected by the emission of TBBPA from residential and factory. The concentration of HBCDs ranged from ND to 6.31 µg/kg, and the diastereoisomer distribution was consistent, showing a trend close to the South China Sea. The composition pattern of HBCDs in the surface sediments from rivers were 41.73%–62.33%, 7.89%–25.54%, and 18.76%–40.65% for α-, β-, and γ-HBCD, respectively, and in the sediments from reservoirs were 26.15%–45.52%, 7.44%–19.23%, and 47.04%–61.89% for α-, β-, and γ-HBCD, respectively. When the sum of concentrations of TBBPA and HBCD in sediments were above high levels, reactive oxygen species in nematodes significantly increased, resulting in an oxidative stress response. Intestinal permeability was also enhanced, causing intestinal damage. In addition, in terms of this study, TBBPA had a greater impact on biotoxicity compared to HBCDs, and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City, Guangdong Province. This study can complement the pollution database in the study area and provide basic data for pollution control. [Display omitted] [ABSTRACT FROM AUTHOR]