Nematodes of concern to public and animal health associated with the invasive snail Achatina fulica, in Sergipe, Northeastern Brazil.

The giant African land snail Achatina fulica is known to be the intermediate host of a number of nematode species that are prejudicial to human and veterinary health, being also an agricultural and urban pest. The present study investigated the presence of nematodes in A. fulica and other terrestrial mollusks in 24 municipalities of Sergipe State, northeastern of Brazil, in the dry and rainy seasons. In 2019 and 2020, the specimens were collected in standard 20 m × 10 m plots (10 min/01 collector), while in 2021, they were collected by convenience sampling. The nematode species were identified based on sequencing of the mitochondrial Cytochrome C Oxidase Subunit I (COI) gene and the ribosomal nuclear Internal Transcribed Spacer (ITS 2). Specimens of A. fulica infected with Angiostrongylus cantonensis, a nematode that causes eosinophilic meningitis (EM) in humans and animals, were collected in four municipalities. Two nematodes of veterinary importance were also identified, Aelurostrongylus abstrusus and Cruzia tentaculata in seven municipalities. This is the first record of Cruzia tentaculata in Sergipe. Free-living nematodes were also found in 18 municipalities. One of these species - Caenorhabditis briggsae - was identified in the municipality of Itabaiana. Specimens of other mollusks species were also collected. Only one of these mollusks, C. fasciata from Japaratuba, was found infected with free-living nematodes. A. fulica showed greater positivity for nematodes in the dry season, especially in the regions of Lower São Francisco River, Greater Aracaju and South Central Sergipe. The probability of infection increased when mollusks were larger and more recurrent in plots. Given that A. cantonensis is the etiological agent of EM and was found associated to A. fulica in four municipalities, it will be important to implement programs of continuous monitoring of the mollusk's fauna, combined with educational programs that provide information necessary to control A. fulica.

Nematofauna of Bryconops cf. affinis (Characiformes, Iguanodectidae) and Saxatilia brasiliensis (Cichliformes, Cichlidae) from the Munim River basin, Northeastern Brazil.

Populations of freshwater species have been declining rapidly and species are becoming extinct. Thus, understanding freshwater species distribution, trends and patterns is required. The Munim River basin is situated in a region with a phytogeographic interface between the Amazon and Cerrado biomes. Although the Munim basin ichthyofauna is currently relatively well-known, data on its helminth fauna is scarce. The present study aimed to characterize the nematofauna of Bryconops cf. affinis (Günther) and Saxatilia brasiliensis (Bloch) from two different localities in the middle section of the Munim River, and thus to contribute to the knowledge of biodiversity in this region. Specimens of Bryconops cf. affinis were parasitized with the nematodes Procamallanus (Spirocamallanus) krameri (Petter, 1974) and "Porrocaecum-like" species (larvae) in both localities. Saxatilia brasiliensis presented the nematodes P. (S.) krameri, Pseudoproleptus sp. (larvae), Cucullanus sp. and Procamallanus sp. (larvae). Procamallanus (S.) krameri was found parasitizing S. brasiliensis only from the Feio stream. Morphometric data and parasitological parameters are given. The present study provides the first record of nematodes for B. cf. affinis and for S. brasiliensis contributing to the knowledge of the helminth fauna of freshwater fishes from locations that have not yet been studied, such as the Munim River basin.

Metazoan endoparasites of snakes from Argentina: Review and checklist with distributional notes and remarks.

This article presents a checklist of metazoan parasites of snakes from Argentina, along with a comprehensive review of the relevant literature published between 1922 and June 2023, covering various aspects of interest. We compiled 34 species of metazoan endoparasites from 28 studies. The subclass Digenea showed the highest number of species (n = 22 species), followed by the phylum Nematoda (n = 8 species), and the subclass Pentastomida (n = 3 species and 1 taxa inquirenda). Dipsadidae was the family of snakes with the most species examined for metazoan endoparasites (n = 20 species). In contrast, Viperidae had the largest number of specimens surveyed (n = 343). Of 23 provinces, 15 (65.2%) presented at least one report of metazoan endoparasites in snakes. The northeastern provinces showed the highest richness of metazoan endoparasites and host diversity. Many articles focused on taxonomy, but studies on parasite ecology were not found. Although taxonomic accuracy was high in most reports, some records were correctly deposited in zoological collections or geo-referenced. This is the first attempt to include all groups of metazoan endoparasites of snakes from Argentina in a single checklist in the last century.

Gastrointestinal nematodes in Cuniculus paca (Linnaeus, 1766) from hunting fauna in the Western Amazonian region.

Cuniculus paca, commonly known as the paca, is a rodent of the Cuniculidae family that is widely distributed throughout the Americas, including all Brazilian territories, and is abundant in the Amazon region. It is one of the most hunted species and faces significant predation in the extreme western Amazon region of Brazil because it constitutes a staple in the diet of local communities, for subsistence and commercial purposes. Understanding the helminthic fauna of these animals is of paramount importance, given that some nematodes have zoonotic potential and may pose risks to consumer health. This study aimed to contribute to the records of the nemtodes of this highly consumed species in the Amazon region, highlighting the occurrence of gastrointestinal parasites in free-living pacas intended for human subsistence consumption. The study was conducted in the Paranã da Floresta community, located in the municipality of Guajará, Amazonas from 2022 to 2023. The community members hunted this rodent for consumption and voluntarily provided the viscera for analysis. Nematodes were extracted from each organ. The organs were opened, and the contents were processed using a sieve (0.15 mm) and subsequently evaluated separately. In total, 10,157 nematodes were found in the 14 pacas. Based on morphological analyses, the nematodes were identified as Heligmostrongylus sedecimradiatus (n = 10,068), Trichuris sp. (n = 85), and Physaloptera sp. (n = 4). This study provides insights into the nematodes diversity of free-living pacas in the extreme Western Amazon region, emphasizing the importance of sanitary surveillance and public awareness of the risks associated with bushmeat consumption.

Blood parasites of water frogs (Pelophylax esculentus complex) from the Danube Delta, Romania.

Water frogs of the genus Pelophylax host a variety of parasites, from protozoa to helminths. Among the blood parasites, representatives of Apicomplexa, Trypanosoma and Nematoda show the highest prevalence. In this study, we focused on blood parasites of water frogs living in the Danube Delta, Romania. In total, 74 individuals of P. ridibundus and eight individuals of P. esculentus from six localities were examined. Blood parasites were detected microscopically and using a molecular marker (18S rDNA). 89.77% of frogs from all investigated localities were found to be infected with at least one parasitic group, specifically with haemogregarines (84.09%), nematodes (1.14%), and trypanosomes (63.64%). The parasitemia of haemogregarines and trypanosomes differed significantly among the studied locations. There was no statistically significant difference in parasitemia between male and female hosts. However, adults were found to have a significantly higher parasitemia in comparison with subadults infected with haemogregarines. Correlation between parasitemia and the body length of frogs infected with haemogregarines was also significant (r = 0.226). By comparing the 18S rDNA sequences with the corresponding GenBank sequences, Hepatozoon species identified in water frogs showed a close similarity (98.1-99.8%) to Hepatozoon magna. Trypanosomes showed the highest sequence similarity to Trypanosoma sp. isolate R10 clone L2-3, Trypanosoma ranarum, and Trypanosoma cobitis.

Epidemiology and diversity of gastrointestinal tract helminths of wild ruminants in sub-Saharan Africa: a review.

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

Cucullanus lithodorasi n. sp. (Nematoda: Cucullanidae), a parasite of Lithodoras dorsalis (Siluriformes: Doradidae) on the north coast of Brazil.

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

Occurrence of gastrointestinal nematodes in lambs in Norway, as assessed by copromicroscopy and droplet digital polymerase chain reaction.

BACKGROUND: Gastrointestinal nematodes (GINs) have a major impact on sheep production, health, and welfare worldwide. Norway is no exception, but there are only a few studies on the prevalence of GINs in Norwegian sheep. The aim of this study was to investigate the current occurrence of the most important nematodes in sheep flocks in Norway. Faecal samples were collected from flocks in 2021/2022, mainly from three geographical regions in Norway, i.e., northern, eastern, and western. In each of 134 flocks included, individual samples from 10 lambs (autumn) were pooled. Third stage larvae (L3) were cultivated and harvested (Baermann method) from the pooled samples. The DNA was then extracted and further analysed using droplet digital PCR (ddPCR). This enables assessment of the proportions of the three most important nematode species/genera, i.e., H. contortus, T. circumcincta, and Trichostrongylus. The fractional abundance/relative proportion of each species/genus was assessed by performing duplex assays with universal strongyle and species/genus-specific primers and probe sets. In addition, the occurrence of Nematodirus eggs was assessed by standard faecal egg counts (i.e., McMaster method). RESULTS: Of the 134 flocks sampled, 24 were from the northern region, 31 from eastern, and 71 from western Norway. In addition, some flocks from central (n = 7), and southern (n = 1) Norway were included. Among the sampled flocks, T. circumcincta occurred most commonly (94%), followed by H. contortus (60%) and Trichostrongylus (55%), and Nematodirus (51%). In general, mixed infections were observed, with 38% and 18% of flocks infected with three or all four genera, respectively. CONCLUSIONS: The results of this study indicate that GINs are widespread in Norway. Teladorsagia circumcincta seems to be present in most flocks based on this screening. Moreover, the results show that Nematodirus spp. infect lambs throughout the country, predominantly N. battus, and indicate that this nematode has become more abundant, which could lead to an increase in nematodirosis.

Endoparasitic helminth fauna and diet of Geophagus sveni (Pisces) in Upper Paraná River basin.

In freshwater ecosystems, parasite infection patterns are influenced by factors including spatial-temporal variations, host diet, and habitat. Fish often change diets, affecting their parasite communities. This study focused on non-native host fish Geophagus sveni, aiming to characterize diet and endoparasitic helminth fauna patterns in the invaded area, investigating spatial and seasonal possible differences of endoparasite infections and correlating with host diet, in São José dos Dourados River and Tietê River areas. The host fish were collected in these areas during the dry and rainy season using gillnets. The endoparasites were collected and preserved in alcohol and identified using taxonomic methods, and stomach contents were examined for diet analysis. Parasitism descriptors were calculated and evaluated spatially and seasonally by ANOVA and the Kruskal-Wallis tests. PERMANOVA assessed G. sveni diet differences, and RDA correlated the endohelminth abundance with the host diet. Two endoparasites were recorded: metacercariae of Austrodiplostomum compactum (Trematoda) and larvae and adults of Raphidascaris (Sprentascaris) lanfrediae (Nematoda). Spatial differences were observed for the mean abundance and prevalence of R. (S.) lanfrediae and A. compactum prevalence. Seasonal variations of parasitic descriptors occurred for the nematode in the Tietê River area. The detritus and aquatic insects were the most consumed items by G. sveni. Detritus consumption positively correlates with nematode abundance. The findings indicate that factors such as artificial channels and rainfall, which can influence resource availability, may affect the fish's diet and potentially influence the structure of its endoparasite community. The study emphasizes the importance of understanding trophic chain-transmitted parasites and calls for further research in Neotropical environments.

Comparison of traditional copromicroscopy with image analysis devices for detection of gastrointestinal nematode infection in sheep.

Sustainable parasite control practices are necessary to combat the negative effects of gastrointestinal nematodes on animal health and production while reducing the selection pressure for anthelmintic resistance. Parasite diagnostic tests can inform treatment decisions, the timing and effectiveness of treatment and enable livestock breeding programmes. In recent years new diagnostic methods have been developed, some incorporating machine learning (ML), to facilitate the detection and enumeration of parasite eggs. It is important to understand the technical characteristics and performance of such new methods compared to long standing and commonly utilised methods before they are widely implemented. The aim of the present study was to trial three new diagnostic tools relying on image analysis (FECPAKG2, Micron and OvaCyte) and to compare them to traditional manual devices (McMaster and Mini-FLOTAC). Faecal samples were obtained from 41 lambs naturally infected with gastrointestinal nematodes. Samples were mixed and separated into 2 aliquots for examination by each of the 5 methods: McMaster, Mini-FLOTAC, FECPAKG2, Micron and OvaCyte. The techniques were performed according to their respective standard protocols and results were collected by trained staff (McMaster and Mini-FLOTAC) or by the device (FECPAKG2, Micron and OvaCyte). Regarding strongyle worm egg count, McMaster values varied from 0 to 9,000 eggs per gram (EPG). When comparing replicate aliquots, both the Mini-FLOTAC and Micron methods displayed similar repeatability to McMaster. However, we found FECPAKG2 and OvaCyte significantly less precise than McMaster. When comparing parasite egg enumeration, significant positive linear correlations were established between McMaster and all other methods. No difference was observed in EPG between McMaster and Mini-FLOTAC or FECPAKG2; however, Micron and OvaCyte returned significantly higher and lower EPG, respectively, compared to McMaster. The number of eggs ascribed to other parasite species was not sufficient for performing a robust statistical comparison between all methods. However, it was noted that FECPAKG2 generally did not detect Strongyloides papillosus eggs, despite these being detected by other methods. In addition, Moniezia spp and Trichuris spp eggs were detected by OvaCyte and Mini-FLOTAC, respectively, but not by other methods. The observed variation between traditional and new methods for parasite diagnostics highlights the need for continued training and enhancing of ML models used and the importance of developing clear guidelines for validation of newly developed methods.

Effect of cattle and horse feces storage methods on Nematode egg viability and sensitivity for egg hatch test.

The aim of the present study was to validate methods of stool sample conservation for the egg hatch test (EHT). This study involved the use of a bovine naturally infected predominantly by Cooperia spp. and one equine naturally infected predominantly by cyathostomins characterized as susceptible to benzimidazoles in the EHT. Fecal samples were submitted to three treatments: aerobic methods (anaerobic storage in plastic bottles, anaerobic storage in vacuum-sealed bags or aerobic storage in plastic bags), under two temperature conditions (room temperature and refrigeration) analyzed at four different assessment times (48, 72, 96 and 120 h). As the standard test, an assay was also performed within 3 h. The tests were performed in triplicate for each drug concentration and with three experimental repetitions at one-week intervals. Two criteria were used for the storage methods: hatchability in the negative control group and sensitivity of the eggs to thiabendazole, comparing the EC50 and 95% confidence interval for each treatment to those of the standard test and the other repetitions. Bovine samples can be stored for up to 96 h and refrigerated vacuum storage can be used, ensuring hatchability of the negative control and sensitivity of the eggs to thiabendazole. For equine samples, no forms of storage were indicated due to the variation among the repetitions and the reduction in the sensitivity of the eggs to thiabendazole, which could result in a false positive detection of resistance.

Biomarkers of gastrointestinal nematodes in beef cattle raised in a tropical area.

Biomarkers are specific molecular, histological, or physiological characteristics of normal or pathogenic biological processes and are promising in the diagnosis of gastrointestinal nematodes (GINs). Although some biomarkers have been validated for infection by Ostertagia sp. in cattle raised in temperate regions, there is a lack of information for tropical regions. The aim of this project was to assess potential biomarkers and validate the most promising. In the first study, 36 bovines (Nelore breed) naturally infected by GINs were distributed into two groups: infected (not treated with anthelmintic) and treated (treated with fenbendazole on days 0, 7, 14, 21, 28, 42, and 56). The variables of interest were live weight, fecal egg count, hemogram, serum biochemical markers, phosphorus, gastrin, and pepsinogen. In the second step, pepsinogen was assessed in cattle of the Nelore breed distributed among three groups: infected (not treated with anthelmintic), MOX (treated with moxidectin), and IVM + BZD (treated with ivermectin + albendazole). In the first study, no difference between groups was found for weight, albumin, hematocrit (corpuscular volume [CV]), erythrocytes, or hemoglobin. Negative correlations were found between pepsinogen and both CV and albumin, and albumin was negatively correlated with the percentage of Haemonchus sp. in the fecal culture. Among the biomarkers, only pepsinogen differentiated treated and infected (beginning with the 28th day of the study). In the second study, a reduction in pepsinogen was found after anthelmintic treatment. Therefore, pepsinogen is a promising biomarker of worms in cattle naturally infected by the genera Haemonchus and Cooperia in tropical areas.

Faecal egg count reduction tests and nemabiome analysis reveal high frequency of multi-resistant parasites on sheep farms in north-east Germany involving multiple strongyle parasite species.

Anthelmintic resistance in sheep parasitic gastrointestinal nematodes is widespread and a severe health and economic issue but prevalence of resistance and involved parasite species are unknown in Germany. Here, the faecal egg count reduction test (FECRT) was performed on eight farms using fenbendazole, ivermectin and moxidectin and on four farms using only moxidectin. A questionnaire was used to obtain data on management practices to potentially identify risk factors for presence of resistance. All requirements of the recently revised WAAVP guideline for diagnosing anthelmintic resistance using the FECRT were applied. Nematode species composition in pre- and post-treatment samples was analysed with the nemabiome approach. Using the eggCounts statistic package, resistance against fenbendazole, ivermectin and moxidectin was found on 7/8, 8/8 and 8/12 farms, respectively. No formal risk factor analysis was conducted since resistance was present on most farms. Comparison with the bayescount R package results revealed substantial agreement between methods (Cohen's κ = 0.774). In contrast, interpretation of data comparing revised and original WAAVP guidelines resulted in moderate agreement (Cohen's κ = 0.444). The FECR for moxidectin was significantly higher than for ivermectin and fenbendazole. Nemabiome data identified 4 to 12 species in pre-treatment samples and treatments caused a small but significant decrease in species diversity (inverse Simpson index). Non-metric multidimensional scaling and k-means clustering were used to identify common patterns in pre- and post-treatment samples. However, post-treatment samples were scattered among the pre-treatment samples. Resistant parasite species differed between farms. In conclusion, the revised FECRT guideline allows robust detection of anthelmintic resistance. Resistance was widespread and involved multiple parasite species. Resistance against both drug classes on the same farm was common. Further studies including additional drugs (levamisole, monepantel, closantel) should combine sensitive FECRTs with nemabiome data to comprehensively characterise the anthelmintic susceptibility status of sheep nematodes in Germany.

Three new species of free-living marine nematodes of the Microlaimus genus (Nematoda: Microlaimidae) from the continental shelf off northeastern Brazil (Atlantic Ocean).

Three new species of the Microlaimus genus (Nematoda: Microlaimidae) are described from sample sediments collected in the South Atlantic, along the Continental Shelf break of Northeastern Brazil. Microlaimus paraundulatus sp. n. possesses four setiform cephalic sensillae, a buccal cavity with three small teeth, arched and slender spicules and a wave-shaped gubernaculum. Microlaimus modestus sp. n. is characterized by four small cephalic sensillae, a buccal cavity with three teeth (one large dorsal tooth), cephalated spicules and a strongly arched gubernaculum in the distal region. Microlaimus nordestinus sp. n. is characterized by the following set of features: relatively long body, eight rows of hypodermal glands that extend longitudinally along the body and a funnel-shaped gubernaculum surrounding the spicules at the distal end. An amendment of the diagnosis is proposed for the genus.

Effect of Soil Temperature on Canine Soil-Transmitted Nematodes in Kandy District with the First Record of Hookworm, Ancylostoma tubaeforme from Sri Lanka.

PURPOSE: Soil-transmitted nematodes (STNs) are widespread in tropical and subtropical regions, particularly where the communities are socio-economically challenged. We investigated the effect of soil temperature on the prevalence and intensity of STN infection in free-roaming dogs. METHODS: Fresh faecal samples collected from free-roaming dogs in Digana and Pussellawa town areas in the Kandy District, Sri Lanka, were microscopically analysed for canine STNs. Soil temperature was measured at each sampling site. Highly prevalent canine hookworm Ancylostoma, was further studied using PCR and sequencing, followed by phylogenetic analysis. RESULTS: The soil temperature ranged between 28 and 31 °C (mean = 29.79 °C) and 18-21 °C (mean = 19.52 °C) in Digana and Pussellawa, respectively, showing a significant difference in the two sites (Students t-test t = 1.68, p < 0.0001). Of the total 44 dogs sampled, 41 (93.2%) were positive for STNs. During microscopic analysis, five nematodes: Ancylostoma spp., Capillaria sp., Strongyloides sp., Toxocara canis, and Trichuris sp., were identified. Ancylostoma species (93.2%) were the most prevalent, followed by Strongyloides sp. (22.7%) and Toxocara canis (15.9%). Infection prevalence of Strongyloides sp. was higher in Digana (40.9%) compared to that in Pussellawa (4.5%; Chi-square test, χ2 = 8.28, p = 0.004) and also the infection intensity from Digana (EPG = 8.02 ± 20.2) compared to that from Pussellawa (0.45 ± 2.1; Mann Whitney U test, p = 0.006). Amplicons (ITS1-5.8S-ITS2) of the expected size for A. caninum, and A. tubaeforme were produced. An A. caninum sequence reported here (OQ101719) illustrated the highest similarity of 99.2% to one of the local sequences (MZ707153) upon pairwise comparison. CONCLUSION: Digana, with a higher soil temperature than Pussellawa, had a significantly higher prevalence and infection intensity, particularly Strongyloides sp. This study also signifies the first molecular identification of hookworm species A. tubaeforme in Sri Lanka.

Nematodes and trematodes associated with terrestrial gastropods in Nottingham, England.

A parasitological survey of terrestrial slugs and snails was conducted at popular dog walking locations across the city of Nottingham, with the intensions of finding gastropods infected with parasites of medical (or veterinary) importance such as lungworm (metastrongyloid nematodes) and trematodes. A total of 800 gastropods were collected from 16 sites over a 225 km2 area. The extracted nematodes and trematodes were identified by molecular barcoding. Of the 800 gastropods collected, 227 were infected (172 had nematode infections, 37 had trematode infections and 18 had both nematode and trematode infections). Of the nematode infected gastropods genotyped, seven species were identified, Agfa flexilis, Angiostoma gandavense, Angiostoma margaretae, Cosmocerca longicauda, Phasmarhabditis hermaphrodita, Phasmarhabditis neopapillosa and an unknown Cosmocercidae species. Of the trematode infected gastropods genotyped, four species were identified, Brachylaima arcuate, Brachylaima fuscata, Brachylaima mesostoma and an unknown Plagiorchioidea species. No lungworm species were found within the city of Nottingham. To our knowledge, this study represents the first survey of gastropod-associated nematodes and trematodes in the East midlands of the United Kingdom.

Pelodera strongyloides in the critically endangered Apennine brown bear (Ursus arctos marsicanus).

Skin biopsies from 20 Apennine brown bears (Ursus arctos marsicanus), 17 of which displaying skin lesions, were investigated by histopathology. Different degrees of dermatitis characterized by folliculitis and furunculosis accompanied by epidermal hyperplasia and epidermal and follicular hyperkeratosis were detected. In the most severe lesions, the superimposition of traumatic wounds, probably self-induced by scratching, was observed. In 8 out of 17 (47.0%) affected bears, cross- and longitudinally-sectioned nematode larvae were present within the lumen of hair follicles, whose localization and morphological characteristics were consistent with Pelodera strongyloides. P. strongyloides is a free-living saprophytic nematode whose third-stage larvae can invade the skin causing pruritic dermatitis in several mammalian species. This is the first report of Pelodera infection in the brown bear. Although capable of causing primary dermatitis, the finding of Pelodera is not sufficient to conclude that it is the cause of the lesions observed in bears. Nevertheless, the high prevalence of the infection is indicative of a diffuse phenomenon that requires further specific investigations given the interest and conservational relevance of this relict bear population.

Helminth and ectoparasitic faunas of the Harris's hawk, Parabuteo unicinctus (Accipitriformes: Accipitridae), in Chile: new data on host-parasite associations for Neotropical raptors / Helmintos e ectoparasitas do gavião-asa-de-telha (Accipitriformes: Parabuteo unicinctus) no Chile: novas associações parasita-hospedeiro para os rapinantes neotropicais

Abstract Birds of prey harbor a wide spectrum of various parasites, mostly with a heteroxenous life cycle. However, most reports on their parasites come from Europe. Although the Harris's hawk (Parabuteo unicinctus) is a widespread species in America, parasitological surveys on this hawk are mostly focused on coprological findings and ectoparasites, with poor attention paid to helminths. The aim of this study was to gather new and additional data on host-parasite associations for the Harris's hawk. Twenty-nine birds from central and southern Chile were necropsied. Further, nine birds from a rehabilitation center and 22 museum specimens were inspected for ectoparasites. Sixty-eight percent of birds hosted at least one parasite species. Four lice species, one mite species and eight helminth species (five nematodes, two platyhelminthes and one acanthocephalan) were recorded. Parasitic lice Colpocephalum nanum and Nosopon chanabense, and a nematode Cyathostoma (Hovorkonema) americana were recorded for the first time in raptors from the Neotropics. A feather mite, Pseudalloptinus sp., nematodes, Physaloptera alata and Microtetrameres sp., and a trematode Neodiplostomim travassosi, were recorded for the first time in Chile. The presence of diverse heteroxenous helminths reported here in the Harris's hawk could be explained by the generalist diet of this raptor.

Resumo As aves de rapina representam uma fonte importante de parasitas heteroxenos. Porém, a maioria dos relatos são da Europa. O gavião-asa-de-telha (Parabuteo unicinctus) é uma espécie amplamente distribuída no continente Americano, porém estudos parasitológicos nessas aves têm documentado achados coprológicos e ectoparasitas, com poucos relatos sobre endoparasitas como helmintos. Por essa razão, o objetivo deste estudo foi descrever novas associações parasita-hospedeiro para o gavião-asa-de-telha e rapinantes neotropicais. Vinte nove aves provenientes do centro e sul do Chile foram submetidas à necropsia. Por outro lado, nove aves de um centro de reabilitação e 22 espécimes de museu foram inspecionados em busca de ectoparasitas. Do total de aves, 68,3% foram identificadas como portadoras de pelo menos uma espécie de parasita. Quatro espécies de piolhos, um ácaro e oito helmintos (cinco nematoides, dois platelmintos e um acantocéfalo) foram registrados. Os piolhos Colpocephalum nanum, Nosopon chanabense e o nematóide Cyathostoma (Hovorkonema) americana são reportados pela primeira vez em rapinantes neotropicais. Colpocephalum nanum, N. chanabense, Pseudalloptinus sp., Physaloptera alata, Microtetrameres sp., C. (H.) americana e Neodiplostomim travassosi, são reportados pela primeira vez no Chile. A diversidade de helmintos heteróxenos, identificados neste trabalho, poderia ser explicada devido à dieta geralista do gavião-asa-de-telha.

Seasonal epidemiology of gastrointestinal nematodes of cattle in the northern continental climate zone of western Canada as revealed by internal transcribed spacer-2 ribosomal DNA nemabiome barcoding.

BACKGROUND: Gastrointestinal nematode (GIN) epidemiology is changing in many regions of the world due to factors such as global warming and emerging anthelmintic resistance. However, the dynamics of these changes in northern continental climate zones are poorly understood due to a lack of empirical data. METHODS: We studied the accumulation on pasture of free-living infective third-stage larvae (L3) of different GIN species from fecal pats deposited by naturally infected grazing cattle. The field study was conducted on three organic farms in Alberta, western Canada. Grass samples adjacent to 24 fecal pats were collected from each of three different pastures on each farm. Internal transcribed spacer-2 nemabiome metabarcoding was used to determine the GIN species composition of the harvested larvae. The rotational grazing patterns of the cattle ensured that each pasture was contaminated only once by fecal pat deposition. This design allowed us to monitor the accumulation of L3 of specific GIN species on pastures under natural climatic conditions without the confounding effects of pasture recontamination or anthelmintic treatments. RESULTS: In seven out of the nine pastures, grass L3 counts peaked approximately 9 weeks after fecal deposition and then gradually declined. However, a relatively large number of L3 remained in the fecal pats at the end of the grazing season. Nemabiome metabarcoding revealed that Cooperia oncophora and Ostertagia ostertagi were the two most abundant species on all of the pastures and that the dynamics of larval accumulation on grass were similar for both species. Daily precipitation and temperature across the whole sampling period were similar for most of the pastures, and multiple linear regression showed that accumulated rainfall 1 week prior to sample collection had a significant impact on the pasture L3 population, but accumulated rainfall 3 weeks prior to sample collection did not. CONCLUSIONS: The results suggest that the pasture L3 population was altered by short-term microclimatic conditions conducive for horizontal migration onto grass. Overall, the results show the importance of the fecal pat as a refuge and reservoir for L3 of cattle GIN on western Canadian pastures, and provide an evidence base for the risk assessment of rotational grazing management in the region.

Metabarcoding in two isolated populations of wild roe deer (Capreolus capreolus) reveals variation in gastrointestinal nematode community composition between regions and among age classes.

BACKGROUND: Gastrointestinal nematodes are ubiquitous for both domestic and wild ungulates and have varying consequences for health and fitness. They exist as complex communities of multiple co-infecting species, and we have a limited understanding of how these communities vary in different hosts, regions and circumstances or of how this affects their impacts. METHODS: We have undertaken ITS2 rDNA nemabiome metabarcoding with next-generation sequencing on populations of nematode larvae isolated from 149 fecal samples of roe deer of different sex and age classes in the two isolated populations of Chizé and Trois Fontaines in France not co-grazing with any domestic ungulate species. RESULTS: We identified 100 amplified sequence variants (ASVs) that were assigned to 14 gastrointestinal nematode taxa overall at either genus (29%) or species (71%) level. These taxa were dominated by parasites classically found in cervids-e.g. Ostertagia leptospicularis, Spiculopteragia spp. Higher parasite species diversity was present in the Trois Fontaines population than in the Chizé population including the presence of species more typically seen in domestic livestock (Haemonchus contortus, Bunostomum sp., Cooperia punctata, Teladorsagia circumcincta). No differences in parasite species diversity or community composition were seen in the samples collected from three zones of differing habitat quality within the Chizé study area. Young roe deer hosted the highest diversity of gastrointestinal nematodes, with more pronounced effects of age apparent in Trois Fontaines. The effect of host age differed between gastrointestinal nematode species, e.g. there was little effect on O. leptospicularis but a large effect on Trichostrongylus spp. No effect of host sex was detected in either site. CONCLUSIONS: The presence of some livestock parasite species in the Trois Fontaines roe deer population was unexpected given the isolation of this population away from grazing domestic livestock since decades. Overall, our results illustrate the influence of host traits and the local environment on roe deer nemabiome and demonstrate the power of the nemabiome metabarcoding approach to elucidate the composition of gastrointestinal nematode communities in wildlife.