Adult Nematodes Research Articles

Pour-on administration of eprinomectin to lactating dairy goats: Pharmacokinetics and anthelmintic efficacy.

Lactation is discussed as a physiological covariate which may influence the exposure characteristics of systemically acting drugs including macrocyclic lactones and potentially alter their pharmacological response. This study characterizes for the first time in the same study, the plasma profile and therapeutic anthelmintic efficacy of eprinomectin 5mg/ml solution (EPRINEX® Multi, Boehringer Ingelheim) administered as a pour-on at 1mg per kg body weight to lactating dairy goats. The study was conducted in compliance with VICH GCP and anthelmintic efficacy evaluation guidelines and included 20goats harboring induced adult gastrointestinal and pulmonary nematode infections. The goats were blocked on pre-treatment body weight and randomly allocated either to remain untreated (control) or to be eprinomectin-treated. Plasma samples to determine the plasma disposition kinetics of eprinomectin (B1a component) were obtained at intervals up to 14days following treatment when the animals were necropsied for parasite enumeration and identification. Basic pharmacokinetic parameters of eprinomectin determined in the ten eprinomectin-treated goats were as follows: AUClast , 23.8±9.7day*ng/ml and Cmax , 5.35±2.27ng/ml; individual maximum plasma concentrations were observed from 8 to 48h after treatment (median Tmax , 0.5days). Topical eprinomectin treatment efficacy, based on significant (p<.01) worm burden reductions in eprinomectin-treated animals relative to untreated controls, was ≥97% to 100% against adult Dictyocaulus filaria, Haemonchus contortus, Teladorsagia circumcincta(pinnata/trifurcata), Trichostrongylus axei, T.colubriformis, Cooperia curticei, Nematodirus battus, and Oesophagostomum venulosum. Both pharmacokinetic parameters and anthelmintic activity in lactating dairy goats were similar to those observed in parasitized young growing and adult female non-lactating dairy goats treated with eprinomectin administered as a pour-on.

Development and Validation of Novel PCR Assays for the Diagnosis of Bovine Stephanofilariasis and Detection of Stephanofilaria sp. Nematodes in Vector Flies.

Background: Stephanofilaria spp. nematodes are associated with cutaneous lesions in cattle and other livestock and mammalian wildlife species. In Australia, Haematobia irritans exigua, commonly known as buffalo fly (BF) transmits a well-described but presently unnamed species of Stephanofilaria, which has been speculatively implicated in the aetiology of BF lesions. The sensitivity of current techniques for detecting Stephanofilaria spp. in skin lesions and vector species is low, and there is no genomic sequence for any member of the genus Stephanofilaria currently available in sequence databases. Methods: To develop molecular assays for the detection of the Australian Stephanofilaria sp., skin biopsies were collected from freshly slaughtered cattle with typical lesions near the medial canthus. Adult nematodes and microfilariae were isolated from the biopsies using a saline recovery technique. The nematodes were morphologically identified as Stephanofilaria sp. by scanning electron microscopy. DNA was extracted and the internal transcribed spacer 2 (ITS2) region of rDNA, and the cytochrome c oxidase subunit 1 (cox1) region of mtDNA was amplified and sequenced. Stephanofilaria sp. specific polymerase chain reaction (PCR) and qPCR assays (SYBR Green® and TaqMan™) were developed and optimised from the novel ITS2 sequence obtained. The specificity of each assay was confirmed by testing against nematode species Onchocerca gibsoni and Dirofilaria immitis, as well as host (bovine) and BF DNA. Results: Scanning electron microscopy of the anterior and posterior ends of isolated nematodes confirmed Stephanofilaria sp. A phylogenetic analysis of the cox1 sequence demonstrated that this species is most closely related to Thelazia callipaeda, a parasitic nematode that is a common cause of thelaziasis (or eyeworm infestation) in humans, dogs, and cats. Both conventional and qPCR assays specifically amplified DNA from Stephanofilaria sp. Conventional PCR, TaqMan™, and SYBR Green® assays were shown to detect 1 ng, 1 pg, and 100 fg of Stephanofilaria DNA, respectively. Both qPCR assays detected DNA from single Stephanofilaria microfilaria. Conclusion: Molecular diagnostic assays developed in this study showed high specificity and sensitivity for Stephanofilaria sp. DNA. The availability of an accurate and sensitive PCR assay for Stephanofilaria will assist in determining its role in the pathogenesis of cattle skin lesions, as well as in understanding its epidemiological dynamics. This assay may also have application for use in epidemiological studies with other species of Stephanofilaria, most particularly closely related S. stilesi, but this will require confirmation.

Novel Functions of the Fatty Acid and Retinol Binding Protein (FAR) Gene Family Revealed by Fungus-Mediated RNAi in the Parasitic Nematode, Aphelenchoides besseyi

RNA interference (RNAi) is a powerful tool for the analysis of gene function in nematodes. Fatty acid and retinol binding protein (FAR) is a protein that only exists in nematodes and plays an important role in their life activities. The rice white-tip nematode (RWTN), Aphelenchoides besseyi, is a migratory endoparasitic plant nematode that causes serious damage in agricultural production. In this study, the expression levels of eight RWTN genes were effectively decreased when RWTN was fed Ab-far-n (n: 1–8) hairpin RNA transgenic Botrytis cinerea (ARTBn). These functions of the far gene family were identified to be consistent and diverse through phenotypic changes after any gene was silenced. Such consistency indicates that the body lengths of the females were significantly shortened after silencing any of the eight Ab-far genes. The diversities were mainly manifested as follows: (1) Reproduction of nematodes was clearly inhibited after Ab-far-1 to Ab-far-4 were silenced. In addition, silencing Ab-far-2 could inhibit the pathogenicity of nematodes to Arabidopsis; (2) gonad length of female nematodes was significantly shortened after Ab-far-2 and Ab-far-4 were silenced; (3) proportion of male nematodes significantly increased in the adult population after Ab-far-1, Ab-far-3, and Ab-far-5 were silenced, whereas the proportion of adult nematodes significantly decreased in the nematode population after Ab-far-4 were silenced. (4) Fat storage of nematodes significantly decreased after Ab-far-3, Ab-far-4, and Ab-far-7 were silenced. To our knowledge, this is the first study to demonstrate that Ab-far genes affect sex formation and lipid metabolism in nematodes, which provides valuable data for further study and control of RWTNs.

Trichostrongylus colubriformis infection negatively impacted phosphorus metabolism of lambs

Intestinal endoparasite infection may promote a nutrient competition with host, reducing absorption and performance as consequence. Phosphorus could be more affected due to the main absorption site is the duodenum. Thus, the study measured the performance, phosphorus metabolism, bone density and blood markers in Santa Ines lambs infected Trichostrongylus colubriformis and fed with different phosphorus (P) levels were tested. Eighteen healthy six-month old, castrated male, Santa Ines lambs (initial body weight 22.4 ± 2.7 kg) were randomly assigned to 4 treatments in a 2 × 2 split-plot arrangement. Treatment factors were sufficient (SP) or deficient (DP) dietary P and uninfected (ui) or infected (i) resulting in 4 treatments: SPui, DPui, SPi, and Dpi). Five animals were assigned to each of the infected treatments and 4 to the uninfected treatments. Infection was established using a single oral dose of 40.000 T. colubriformis in the larval stage (L3). All the animals were fed Tifton 85 hay (Cynodon spp.; 60 %) supplemented with cassava and maize gluten meal (40 %). Animals were weighed and blood was sampled weekly. Body composition was estimated twice by computed tomography. P metabolism was assessed by isotope dilution after a bolus infusion of 32P (7.4 M Bq/0.5 mL). Fecal egg counts (FEC) were assessed every 3 days beginning d 18 post-infection, and adult nematodes were counted and characterized (gender, length, and eggs in reproductive tract) at slaughter. The experiment lasted 96 d, and 45 d after infeciton. Statistical procedures were performed using R studio. Infection was successful as evidenced by increased FEC, and the elevated counts were maintained longer with Dpi than SPi. Performance, feed intake, and blood parameters were not affected by treatments. Infected animals had reduced bone density and bone P concentrations as compared to uninfected ones. Endogenous P loss was reduced for DP. Plasma, saliva, and ruminal liquid P concentrations decreased in infected animals. Phosphorus absorption and retention coefficients did not differ by treatment, but the biological half-life (T1/2) of P was reduced for infected animals due to faster blood 32P removal. We concluded that T. colubriformis infection modified P metabolism, and blood P concentrations are an indicator of animal problems, connecting infection and bone mineralization.

Lectin-Mediated Bacterial Modulation by the Intestinal Nematode Ascaris suum.

Ascariasis is a global health problem for humans and animals. Adult Ascaris nematodes are long-lived in the host intestine where they interact with host cells as well as members of the microbiota resulting in chronic infections. Nematode interactions with host cells and the microbial environment are prominently mediated by parasite-secreted proteins and peptides possessing immunomodulatory and antimicrobial activities. Previously, we discovered the C-type lectin protein AsCTL-42 in the secreted products of adult Ascaris worms. Here we tested recombinant AsCTL-42 for its ability to interact with bacterial and host cells. We found that AsCTL-42 lacks bactericidal activity but neutralized bacterial cells without killing them. Treatment of bacterial cells with AsCTL-42 reduced invasion of intestinal epithelial cells by Salmonella. Furthermore, AsCTL-42 interacted with host myeloid C-type lectin receptors. Thus, AsCTL-42 is a parasite protein involved in the triad relationship between Ascaris, host cells, and the microbiota.

First Record of Dichelyne (Cucullanellus) tripapillatus (Nematoda: Cucullanidae) Parasitic in King Soldier Bream Argyrops spinifer (Pisces: Sparidae) in Arabian Gulf, off Iraq

A total of 42 specimens of Argyrops spinifer were caught from Iraqi territorial waters during the period from October 2019 till September 2020. The adult nematodes were isolated from the infected fishes. Morphological features of both males and females of nematodes matched with that of Dichelyne (Cucullanellus) tripapillatus (Gendre, 1927). This nematode is distinguished by the location of nerve ring in relation to the length of oesophagus, as well as the distribution of the ten caudal papillae of males. The record of this species and its subgenus represent its first one in the Arabian Gulf and Iraq.

Hsp-90 and unc-45 depletion induce characteristic transcriptional signatures in coexpression cliques of C. elegans

Nematode development is characterized by progression through several larval stages. Thousands of genes were found in large scale RNAi-experiments to block this development at certain steps, two of which target the molecular chaperone HSP-90 and its cofactor UNC-45. Aiming to define the cause of arrest, we here investigate the status of nematodes after treatment with RNAi against hsp-90 and unc-45 by employing an in-depth transcriptional analysis of the arrested larvae. To identify misregulated transcriptional units, we calculate and validate genome-wide coexpression cliques covering the entire nematode genome. We define 307 coexpression cliques and more than half of these can be related to organismal functions by GO-term enrichment, phenotype enrichment or tissue enrichment analysis. Importantly, hsp-90 and unc-45 RNAi induce or repress many of these cliques in a coordinated manner, and then several specifically regulated cliques are observed. To map the developmental state of the arrested nematodes we define the expression behaviour of each of the cliques during development from embryo to adult nematode. hsp-90 RNAi can be seen to arrest development close to the L4 larval stage with further deviations in daf-16 regulated genes. unc-45 RNAi instead leads to arrested development at young adult stage prior to the programmatic downregulation of sperm-cell specific genes. In both cases processes can be defined to be misregulated upon depletion of the respective chaperone. With most of the defined gene cliques showing concerted behaviour at some stage of development from embryo to late adult, the “clique map” together with the clique-specific GO-terms, tissue and phenotype assignments will be a valuable tool in understanding concerted responses on the genome-wide level in Caenorhabditis elegans.

Bacterial transfer from Pristionchus entomophagus nematodes to the invasive ant Myrmica rubra and the potential for colony mortality in coastal Maine

SummaryThe necromenic nematode Pristionchus entomophagus has been frequently found in nests of the invasive European ant Myrmica rubra in coastal Maine, United States, and may contribute to ant mortality and collapse of colonies by transferring environmental bacteria. Paenibacillus and several other bacterial species were found in the digestive tracts of nematodes harvested from collapsed ant colonies. Serratia marcescens, Serratia nematodiphila, and Pseudomonas fluorescens were collected from the hemolymph of nematode-infected wax moth (Galleria mellonella) larvae. Virulence against waxworms varied by the site of origin of the nematodes. In adult nematodes, bacteria were highly concentrated in the digestive tract with none observed on the cuticle. In contrast, juveniles had more on the cuticle than in the digestive tract. Host species was the primary factor affecting bacterial community profiles, but Spiroplasma sp. and Serratia marcescens sequences were shared across ants, nematodes, and nematode-exposed G. mellonella larvae.

The prevalence of intestinal nematodes among red foxes (Vulpes vulpes) in north-western Poland

BackgroundThe red fox (Vulpes vulpes) is widely distributed in the Northern Hemisphere and Australia. The presence of nematode-infected foxes in urbanized areas increases the risk of transmission of nematodes to domestic dogs and thus, to humans. The aim of this study was to determine the prevalence and species composition of intestinal nematodiasis in red foxes in Western Pomerania, a province in north-western Poland. The intestinal contents of 620 red foxes killed during a government reduction shooting programme were examined for adult nematodes using the sedimentation and counting technique (SCT).ResultsIntestinal nematodes, including Toxocara canis, Toxascaris leonina, Uncinaria stenocephala and Trichuris vulpis, were found in 77.3% (95% CI 73.8–80.4%) of the examined foxes with a mean infection burden of 20.1 nematode per animal. Male and female foxes had similar infection burdens.ConclusionsThe nematodes are present in high prevalence and intensity among foxes in north-western Poland. Furthermore, this high prevalence of nematodes in foxes may likely constitute a health risk to humans and domestic animals due to increasing fox densities in urban and periurban areas.

Isolation and characterization of chemical constituents with in vitro anti-hypertensive and anthelmintic activities of Cinnamomum bejolghota (Buch.-Ham.) sweet leaves: An ethno medicinal plant of North East India

Cinnamomum bejolghota (Buch.-Ham.) Sweet is traditionally use as anthelmintic and cardiotonic agent. The objective of our current experiment is to establish the traditional claim by determining the in vitro anthelmintic and antihypertensive activity of extract and isolated compounds from the leaves of the plant. Isolation of compounds was carried out by bioassay guided method from hexane and ethanol extract. In vitro anti-hypertensive activity was carried out by angiotensin converting enzyme (ACE) inhibitory method. Anthelmintic activity was done by measuring the effect of isolated compounds on the survivability of adult nematode, egg hatching and larval development of Caenorhabditis elegans. From the plant, thirteen compounds (1-13) were characterized by using chromatography and spectroscopic methods and were tested for in vitro anthelmintic and ACE inhibitory activity. Compounds linalool (1), β-sitosterol (6), cinnamic acid (11), fridelin (12) exhibited promising ACE inhibitory activity with IC50 value of 99.02 ± 0.44, 65.87 ± 0.72, 45.36 ± 0.16 and 45.45 ± 2.31 μg/ml respectively. Further, geranial (4) exhibited the highest anthelmintic property when tested against adult C. elegans with an ED50 of 57.55 ± 4.47 µg/ml. Geranial treated eggs showed that at a concentration of 47.65 ± 1.917 µg/ml approximately 50% of the eggs did not hatch and at a concentration of 200 µg/ml compound was very effective in hindering the hatching of eggs (88.66 ± 0.67%). The larval development assay shows that at a concentration of 38.73 ± 2.57 µg/ml survival of about 50% of larvae was observed. To the best of our knowledge, this is the first report of isolation of anthelmintic and antihypertensive chemical moiety from C. bejolghota and can be developed into a novel phyto-pharmaceutical product.

Histopathologic and histomorphometric evaluation of Dipetalonema evansi infection in camel testicular tissue.

Camels are important sources of milk, meat, wool and leather, and are widely used in transportation in arid and semi-arid areas. But their illnesses, especially parasitic diseases, have not been taken into consideration. The Dipetalonema evansi microfilariae are in the blood. Adult nematode is only dedicated to camels and disrupts spermatic arteries, lung arteries, right atrium, and testicles. This study was carried out on testicular samples of camels infected with D. evansi referred from slaughterhouse. In each of the control and contaminated groups, 5 samples were examined. In this study, in addition to the qualitative description of parasite histopathologic lesions, the spermatogenesis process was evaluated quantitatively including spermatogenesis process, diameter of the seminiferous tubules and Johnsen ranking and compared with the control group. Histopathological examination of infected testis with D. evansi showed lumen obstruction of testicular blood vessels by parasites, hypertrophy of blood vessels, degenerative and necrosis changes in the tubules, decreased spermatogenetic activity, increased interstitial space tubules, destruction of the spermatogenic cells. Also, there was a significant difference in the control and contaminated groups in the parameters of spermatogenesis, diameter of the seminiferous tubules and Johnsen score.

Detection of Stephanurus dentatus in wild boar urine using different parasitological techniques.

Stephanurus dentatus is a nematode that parasitizes the urinary tract of domestic and wild Suidae, especially in tropical areas. However, there is a lack of information about stephanurosis in wild boar (Sus scrofa), thus making it necessary to develop sensitive techniques with which to diagnose this pathogen in order to carry out further research. In Spain, the high prevalence of this nematode has been evidenced in Doñana National Park (DNP). The objective of the present work is twofold. The first is to compare the efficacy of three parasitological techniques to detect S. dentatus eggs in the urine of infected wild boar: (i) gravity sedimentation, (ii) sedimentation by centrifugation, and (iii) flotation techniques, while the second is to determine whether the quantification of eggs can serve as an indicative value of the host's parasite intensity. In order to accomplish these purposes, 27 wild boars from DNP were necropsied, and the urinary system of each animal was examined in order to determine parasite intensity. While all the aforementioned techniques can be used to detect eggs in urine, the most effective in terms of egg quantification are sedimentation by gravity and by centrifugation, as they allow a greater number of S. dentatus eggs to be detected. However, none of the results obtained with these techniques significantly correlated with the number of adult nematodes parasitizing the host, signifying that counts in urine can provide guidance on only the parasite intensity of wild boar.

Anthelmintic effect of essential rhizome oil from Hedychium coronarium Koenig (Zingiberaceae) introduced in Northeastern Brazil

Hedychium coronarium is native to Tropical Asia and has been introduced into several Brazilian biomes. Significant biological properties described for the essential oil (EO) from this species' rhizomes include antimicrobial, larvicidal, anti-inflammatory, antioxidant, phytotoxic, and anthelmintic activities. The primary constituents identified in this study by GC-MS in the EO were monoterpenes 1,8-cineole (33.5%), β-pinene (17.0%), α-terpineol (7.7%), α-pinene (7.3%), limonene (5.2%), and p-cymene (4.9%), comprising 75.6% of total oil compounds. The main monoterpenes' EO and standards were tested against N2 (susceptible) and UVR15 (resistant) adult nematode Caenorhabditis elegans strains, with varying dead rates in motility tests.. Nematocidal activity was not attributed to 1,8-cineole and β-pinene, the main H. coronarium rhizome oil components, as both exhibited an inhibitory concentration (IC50) ≥ 5 mg/mL. On the other hand, the α-pinene (IC50, 1.69 mg/mL) and (S)-(-)-limonene (IC50, 1.66 mg/mL) standards demonstrated more efficient action than rhizome oil in motility tests, with significant adult C. elegans nematode mortality rates. These results support the hypothesis that the combination of H. coronarium EO constituents can be helpful as a nematicidal product, due to their synergistic action.

Molecular and morphological characterization of three new species of avian Onchocercidae (Nematoda) with emphasis on circulating microfilariae

BackgroundBlood parasites have been the subject of much research, with numerous reports of the presence of microfilariae in the peripheral blood (circulating microfilariae) of birds belonging to many orders. Current limitations in molecular characterization methods and species identification using morphological characters of circulating microfilariae are major obstacles to improving our understanding the biology of Filarioidea species, particularly in wildlife. The aim of this study was to partially fill these gaps, with particular emphasis on morphological features of microfilariae, which are the most readily accessible stages of these pathogens.MethodsPeripheral blood samples of 206 birds belonging to genera Acrocephalus (five species) and Sylvia (five species) were examined using the buffy coat method to process the blood samples for the presence of microfilariae. Positive birds were dissected to collect adult nematodes. Microfilariae and adult nematodes were described, and sequences of their mitochondrial cytochrome c oxidase subunit I and nuclear 28S rDNA gene fragments were obtained and used for molecular characterization and Bayesian phylogenetic inferences.ResultsOverall prevalence of microfilariae was 2.9%. Microfilariae were found in the blood samples from six birds (2 Acrocephalus scirpaceus and 1 each of A. arundinaceus, Sylvia atricapilla, S. borin and S. curruca), which were dissected. All parasite species observed were new. Eufilaria acrocephalusi sp. n. and Eufilaria sylviae sp. n. were present in subcutaneous, peritracheal and periesophageal connective tissues in A. scirpaceus and S. borin, respectively. Splendidofilaria bartletti sp. n. was found in finger joins of S. atricapilla. Illustrations of microfilariae and adult nematodes are shown, and morphological and phylogenetic analyses identified the DNA barcode haplotypes that are associated with these species. Phylogenetic analysis places the parasites of different genera in different closely related clades.ConclusionsAdult nematode morphological characters, which have been traditionally used in the taxonomy of Filarioidea species, have a phylogenetic value. Importantly, in our study parasites of different genera were readily distinguishable based on the morphology of their microfilariae. The link between molecular and morphology data requires more study in Filarioidea species research, particularly because this approach provides new knowledge on species identity using only readily accessible blood stages (microfilariae), thereby avoiding host dissection and thus minimizing harm to wildlife during research.Graphical

Effect of the Tocotrienol-Rich Fraction (TRF) on the Healthspan of Caenorhabditis elegans

Vitamin E is an established antioxidant. However, the effect of vitamin E on healthspan, which deteriorates during ageing, has not been determined because most related studies have emphasized its effects on lifespan. Therefore, the purpose of this study was to determine the effect of palm tocotrienol-rich fraction (TRF) on the lifespan, locomotion and thermotolerance of Caenorhabditis elegans, which share many common gene sequences with humans. The nematodes were treated with different concentrations of TRF (0 - 200 μg/mL), and the number of surviving nematodes at each concentration (N=30, duplicate) was counted daily under a light microscope to determine the optimal dose of treatment. The nematodes were divided into 3 groups, namely; control, Tween-80 (vehicle) and TRF-treated. Locomotion and thermotolerance were determined on day 4 and 12 of treatment in adult nematodes. ImageJ was used for locomotion analysis, and thermotolerance was determined based on nematode survivals after exposure to 37 °C. TRF-treated C. elegans had significantly longer lifespans compared to controls (P = 0.003). The TRF group (50 μg/mL) had the longest mean lifespan (23.5 days), which was significantly longer compared to controls, (18.5 days; (P = 0.002). However, locomotion was similar between all groups. In the thermotolerance assay, the survival determined on day 4 and day 12 of TRF-treatment was higher compared to controls (P= 0.046). Interestingly, the Tween- 80-treated group showed similar results as the TRF-treated group compared to controls. The findings indicate that TRF prolongs the lifespan and increases the thermotolerance of C. elegans but does not improve the locomotion of the worms as they age.

Mutual adaptations between hosts and parasites determine stress levels in eels.

Invasive parasites may severely affect their new hosts. Two invasive parasites occurring in the European eel (Anguilla anguilla) are the Asian swim bladder nematode Anguillicola crassus and the Ponto-caspian acanthocephalan Pomphorhynchus sp., which were introduced to the river Rhine in the early 1980/90s. The Japanese eel (Anguilla japonica), as the native host of A. crassus, developed mutual adaptations to the swim bladder parasite, which are lacking in the European eel. Therefore, after its spread to Europe, infestations of European eels with A. crassus were found to be more severe and caused massive swim bladder wall damages mainly due to the feeding activity of the adult nematodes. A suppression of the immune system also appears to be likely, which allows secondary infections e.g. by bacteria or other parasites in European eels. Acanthocephalans of the genus Pomphorhynchus have not been described so far in Japanese eels, in contrast to European eels, which regularly show infestations with Pomphorhynchus sp. By using these differentially adapted host-parasite associations for experimental studies, host stress responses were examined in the present study in relation to the degree of mutual adaptations between eel hosts and parasites.Under laboratory conditions, Japanese and European eels were each inoculated with A. crassus and Pomphorhynchus sp., respectively, to investigate their stress responses against differently adapted parasites. The stress response was determined by analyzing plasma levels of cortisol, which is the main corticosteroid hormone during stress response of fish. The results show a strong cortisol release in European eels after infestation with A. crassus whereas Japanese eels only react against Pomphorhynchus sp. infestations. These results are consistent with the initial hypothesis that a low degree of host-parasite adaptations lead to stronger host stress responses against the parasite.

Major antigen and paramyosin proteins as candidate biomarkers for serodiagnosis of canine infection by zoonotic Onchocerca lupi.

Onchocerca lupi (Spirurida: Onchocercidae) is a filarial worm parasitizing domestic carnivores and humans. Adult nematodes usually localize beneath in the sclera or in the ocular retrobulbar of infected animals, whilst microfilariae are found in the skin. Therefore, diagnosis of O. lupi is achieved by microscopic and/or molecular detection of microfilariae from skin biopsy and/or surgical removal of adults from ocular tissues of infected hosts. An urgent non-invasive diagnostic tool for the diagnosis of O. lupi in dog is mandatory. In this study, an immunoproteomic analyses was performed using a combination of immunoblotting and mass spectrometry techniques. Onchocerca lupi major antigen (Ol-MJA) and paramyosin (Ol-PARA) proteins were identified as potential biomarkers for serodiagnosis. Linear epitopes were herein scanned for both proteins using high-density peptide microarray. Sera collected from dog infected with O. lupi and healthy animal controls led to the identification of 11 immunodominant antigenic peptides (n = 7 for Ol-MJA; n = 4 for Ol-PARA). These peptides were validated using sera of dogs uniquely infected with the most important filarioids infesting dogs either zoonotic (Dirofilaria repens, Dirofilaria immitis) or not (Acanthocheilonema reconditum and Cercopithifilaria bainae). Overall, six antigenic peptides, three for Ol-MJA and for Ol-PARA, respectively, were selected as potential antigens for the serological detection of canine O. lupi infection. The molecular and proteomic dataset herein reported should provide a useful resource for studies on O. lupi toward supporting the development of new interventions (drugs, vaccines and diagnostics) against canine onchocercosis.

Solanum linnaeanum and Solanum sisymbriifolium as a sustainable strategy for the management of Meloidogyne chitwoodi

Root-knot nematodes (RKN), Meloidogyne spp., are important crop pests that cause severe losses in crop production worldwide, reducing both productivity and crop quality. Meloidogyne chitwoodi Golden, O'Bannon, Santo & Finley, 1980 is considered a quarantine organism by the European and Mediterranean Plant Protection Organization (EPPO) causing damage in tomato and potato crops. The development of nonchemical and sustainable management strategies to reduce nematode damage is crucial. The resistance of Solanum linnaeanum Hepper & P.-M.L. Jaeger and S. sisymbriifolium Lamarck cv. Sis 6001 to M. chitwoodi was evaluated based on gall index (GI), the Bridge & Page (1980) rating chart and reproduction factor (RF). Both plant species were resistant to M. chitwoodi. Solanum linnaeanum had an average of 519 small root swellings/plant, with 45% adult nematodes inside the roots, all males. Solanum sisymbriifolium had GI ≤ 2 and RF ≤ 1 with a high percentage (69%) of nematodes inside the roots that did not develop beyond the sexually undifferentiated second-stage. The use of S. linnaeanum as a new source of resistance is a good alternative for the control of RKN in the quest to develop nonchemical and sustainable management strategies to protect crops.

The impact of Anguillicoloides crassus (Nematoda) on European eel swimbladder: histopathology and relationship between neuroendocrine and immune cells.

The swimbladder functions as a hydrostatic organ in most bony fishes, including the European eel, Anguilla anguilla. Infection by the nematode Anguillicoloides crassus impairs swimbladder function, significantly compromising the success of the eel spawning migration. Swimbladders from 32 yellow eels taken from Lake Trasimeno (Central Italy) were analysed by histopathology- and electron microscopy-based techniques. Sixteen eels (50%) harboured A. crassus in their swimbladders and intensity of infection ranged from 2 to 17 adult nematodes per organ (6.9 ± 1.6, mean ± s.e.). Gross observations of heavily infected swimbladders showed opacity and histological analysis found a papillose aspect to the mucosa and hyperplasia of the lamina propria, muscularis mucosae and submucosa. Inflammation, haemorrhages, dilation of blood vessels and epithelial erosion were common in infected swimbladders. In the epithelium of parasitized swimbladders, many empty spaces and lack of apical junctional complexes were frequent among the gas gland cells. In heavily infected swimbladders, we observed hyperplasia, cellular swelling and abundant vacuolization in the apical portion of the gas gland cells. Numerous mast cells and several macrophage aggregates were noticed in the mucosal layer of infected swimbladders. We found more nervous and endocrine elements immunoreactive to a panel of six rabbit polyclonal antibodies in infected swimbladders compared to uninfected.

The Vector-Borne Zoonotic Nematode Thelazia callipaeda in the Eastern Part of Europe, with a Clinical Case Report in a Dog in Poland

Thelazia callipaeda is a zoonotic nematode transmitted by drosophilid flies. It causes ocular thelaziosis, a disease of carnivores, such as dogs, cats, and foxes, and also humans. The parasite has thus far been observed in various areas of Eurasia, including 20 countries within Europe. The present study documents its presence in the south-east region of Poland, near the Ukraine border. An adult nematode was removed from the conjunctival sac of a dog showing ocular inflammation and purulent discharge. The dog’s precise origin is unknown. Based on its localization and morphometrical features, the nematode was identified as a Thelazia callipaeda adult male. The present study is the first report of T. callipaeda in a dog in Poland.