Molecular species determination of cyathostomins from horses in Ireland.

Cyathostomins are globally important equine parasites, responsible for both chronic and acute pathogenic effects. The occurrence of mixed infections with numerous cyathostomin species hinders our understanding of parasite epidemiology, host-parasite dynamics, and species pathogenicity. There have been few studies of cyathostomin species occurring in horses in Ireland, where temperate climatic conditions with year-round rainfall provide suitable conditions for infection of grazing animals with bursate nematodes. Here, we amplified and sequenced the ITS-2 region of adult worms harvested at post-mortem from eleven adult horses between August 2018 and June 2020, and recorded species prevalence and abundance of worms recovered from the caecum, right ventral colon and left dorsal colon, using both BLAST and IDTAXA for taxonomic attribution. Phylogenetic relationships and community composition were also recorded and compared with other relevant studies, including a global meta-analysis. Overall, our results agree with previous studies that there does not seem to be a major difference in cyathostomin species occurrence in equids in different geographical regions. We confirmed the results of other workers in relation to the difficulties in discriminating between Cylicostephanus calicatus and Coronocyclus coronatus on the basis of ITS-2 sequences.

GAPEWORM (SYNGAMUS SPP.) PREVALENCE IN WISCONSIN GREATER PRAIRIE CHICKENS (TYMPANUCHUS CUPIDO PINNATUS).

Under Wisconsin state law, the greater prairie chicken (GRPC; Tympanuchus cupido pinnatus) has been listed as a threatened species since 1976. In 2014-15, we conducted a pilot study to determine the prevalence and intensity of gapeworms (Syngamus spp.) in female Wisconsin GRPCs collected from 2 monitored populations. We captured 62 female GRPCs using walk-in-style traps for females and night lighting for juveniles ≥45 days of age. From these individuals, we collected 15 carcasses of radio-marked birds, most of whom died due to predation events. Through dissection, we identified gapeworm in 20% of examined carcasses and report an intensity ranging between 4 and 74 worms.

Profile of endoparasites in dairy cattle in the microregion of São João del-Rei, state of Minas Gerais, Brazil / [Perfil de endoparasitas em bovinos leiteiros na microrregião de São João del-Rei, Minas Gerais, Brasil]

The present study provides the first evaluation of the endoparasite profile in dairy cattle from the microregion of São João del-Rei, Minas Gerais, Brazil, including seasonal variations in parasitic infections. Fecal samples were collected directly from rectum of 123 dairy cows and 160 calves on 15 farms. These were kept in insulated boxes and sent for immediate analysis. Using eggs per gram of feces (EPG) we found the following prevalences: Strongyloidea 43.5%, Moniezia sp. 7.6% and both Strongyloides sp. and Trichuris spp. 2.2%, in dairy cows. In calves, the prevalence was Strongyloidea 50.9%, Moniezia sp. 5.6% and Strongyloides sp. 1.9%. The third-stage larvae recovered from coprocultures from cows and calves consisted mainly of Cooperia spp., Haemonchus spp. and Ostertagia spp. EPG counts were significantly higher in calves. Regarding seasonality, the EPG counts and prevalence of Moniezia sp. tended to be higher in the dry period, whereas those of Strongyloidea were higher in the rainy season. Evidence suggests that parasite control and prophylaxis were inadequately managed on the farms studied here. The present parasitological profile correlates with those found by other similar studies, indicating that the main problem is still the inadequate management of parasite control and prophylaxis by farmers.(AU)

O presente estudo representa a primeira avaliação do perfil de endoparasitos em bovinos leiteiros da microrregião de São João del-Rei, Minas Gerais, Brasil, e das variações sazonais das infecções parasitárias. Foram avaliadas amostras fecais de 123 vacas e 160 bezerros de 15 propriedades rurais, coletadas diretamente do reto, mantidas em caixas térmicas isoladas e analisadas imediatamente. A contagem de ovos por grama de fezes (OPG) revelou prevalências de 43,5% de Strongyloidea, 7,6% de Moniezia sp. e 2,2% de Strongyloides sp. e Trichuris spp. em vacas leiteiras. As prevalências de OPG em bezerros foram 50,9% de Strongyloidea, 5,6% de Moniezia sp. e 1,9% de Strongyloides sp. As larvas do terceiro estádio recuperadas de coproculturas de vacas e bezerros foram principalmente de Cooperia spp., Haemonchus spp. e Ostertagia spp. OPG dos parasitos foram significativamente maiores em bezerros. Em relação à sazonalidade, OPG e a prevalência de Moniezia sp. tenderam a ser maiores durante a estação seca, enquanto OPG de Strongyloidea foram maiores na estação chuvosa. Com base nos resultados, é possível concluir que o manejo antiparasitário nas propriedades estudadas não é realizado de maneira plenamente satisfatória. O presente perfil parasitológico se assemelha a outros encontrados em estudos semelhantes, indicando que o maior problema ainda é o manejo antiparasitário inadequado realizado nas propriedades de bovinos leiteiros.(AU)

Meta-analysis of cyathostomin species-specific prevalence and relative abundance in domestic horses from 1975-2020: emphasis on geographical region and specimen collection method.

BACKGROUND: Cyathostomins infect virtually all horses, and concomitant infections with 10 or more species per horse is standard. Species-specific knowledge is limited, despite potential species bias in development of disease and anthelmintic resistance. This is the first meta-analysis to examine effects of geographical region and cyathostomin collection method on reported composition of cyathostomin communities. METHODS: Thirty-seven articles published in English in 1975 or later, in which adults of individual species were systematically enumerated, were included. Seven regions; North America, South America, eastern Europe, western Europe, northern Europe, southern Africa, and Oceania, and three cyathostomin collection methods; (i) standard necropsy recovery from the large intestine, (ii) critical test collection from post-treatment feces and necropsy, and (iii) diagnostic deworming recovery solely from post-treatment feces, were considered. Generalized mixed linear models analyzed the effects of region and collection method on species-specific prevalence and relative abundance. Species richness was analyzed by mixed linear models. RESULTS: Definitively, the most prevalent and relatively abundant species were Cylicocyclus nassatus (prevalence = 93%, relative abundance = 20%), Cylicostephanus (Cys.) longibursatus (93%, 20%), and Cyathostomum catinatum (90%, 16%). A bias toward horses with high infection intensities and cyathostomin collection from feces resulted in North American critical tests and eastern European diagnostic deworming overestimating the species-specific prevalence and underestimating the relative abundance of rare/uncommon species compared to respective intra-regional standard necropsies. North American critical tests underestimated species richness due partially to identification key errors. Inter-regional standard necropsy comparisons yielded some species-specific regional differences, including a significantly higher Cys. longibursatus prevalence and relative abundance in North America (92%, 33%) than in eastern Europe (51%, 7%) (P > 0.0001). Localization of critical tests to North America and diagnostic deworming to Eastern Europe precluded expansive 'region by collection method' interaction analyses. CONCLUSION: We provide substantial data to inform study design, e.g. effect and study size, for cyathostomin research and highlight necessity for method standardization and raw data accessibility for optimal post-factum comparisons.

Protozoan and Helminth Infections of Aviary-Reared Alectoris rufa (Galliformes: Phasianidae) before Releasing for Hunting in the Czech Republic: Infection Dynamics and Potential Risks.

Age-related dynamics of protozoan and helminth infections in the red-legged partridge, Alectoris rufa, were studied in an intensive breeding aviary in the Czech Republic before releasing birds for hunting purposes. Pooled fecal samples (n = 900) were examined over 3 rearing seasons (2012-2014). A total of 4 protozoan species, Cryptosporidium baileyi, Cryptosporidium meleagridis, Eimeria kofoidi, and Eimeria legionensis, and 4 helminths, Capillaria phasianina, Eucoleus perforans, Heterakis gallinarum, and Syngamus trachea, was found. The most common parasite was S. trachea (prevalence 20-26%) in dead birds (n = 99), which represents a high risk for breeders. Co-occurrence of protozoans and helminths indicated similarities in infection dynamics throughout the 3 breeding seasons. Mixed infections of Cryptosporidium baileyi and C. meleagridis with other parasitic species are reported for the first time. Our findings provide new insights into breeding of A. rufa and may help to improve the efficacy of disease control strategies and prevention, especially with the potential for spreading of parasitic infections to wildlife through released birds into open areas.

Causes of Fatal Cyathostomiasis in Brown Booby (Sula leucogaster) from Brazil: Identification of Pathogen and Implications for Management.

Fatal infection by Cyathostoma (Cyathostoma) phenisci (Nematoda: Syngamidae), was identified in 2 of 52 brown boobies (Sula leucogaster) collected on beaches in the state of Rio de Janeiro, Brazil, and admitted to the veterinary clinic for rehabilitation. Both infected birds were in poor physical condition, with atrophied pectoral muscles, and died soon after starting treatment. The parasitological and pathological examination of the carcasses revealed the presence of C. (C.) phenisci in the trachea, resulting in tracheitis, as well as severe parasitic granulomatous bronchopneumonia caused by eggs deposited in the lungs. In our opinion, these serious pathological changes were the primary cause of chronic respiratory illness. This is the first description of fatal cyathostomiasis in a fish-eating avian host caused by infection by a member of the subgenus Cyathostoma (Cyathostoma). Therefore, it is reasonable to consider C. (C.) phenisci to be a real threat to a wide range of their definitive hosts, and cyathostomiasis should be considered in the differential diagnosis for fish-eating marine birds, even in cases without respiratory signs. This is also the first record of the genus Cyathostoma in Brazil.

GLOWORM-PARA: a flexible framework to simulate the population dynamics of the parasitic phase of gastrointestinal nematodes infecting grazing livestock.

Gastrointestinal nematodes are a significant threat to the economic and environmental sustainability of keeping livestock, as adequate control becomes increasingly difficult due to the development of anthelmintic resistance in some systems and climate-driven changes to infection dynamics. To mitigate any negative impacts of climate on gastrointestinal nematode epidemiology and slow anthelmintic resistance development, there is a need to develop effective, targeted control strategies that minimise the unnecessary use of anthelmintic drugs and incorporate alternative strategies such as vaccination and evasive grazing. However, the impacts climate and gastrointestinal nematode epidemiology may have on the optimal control strategy are generally not considered, due to lack of available evidence to drive recommendations. Parasite transmission models can support control strategy evaluation to target field trials, thus reducing the resources and lead-time required to develop evidence-based control recommendations incorporating climate stochasticity. Gastrointestinal nematode population dynamics arising from natural infections have been difficult to replicate and model applications have often focussed on the free-living stages. A flexible framework is presented for the parasitic phase of gastrointestinal nematodes, GLOWORM-PARA, which complements an existing model of the free-living stages, GLOWORM-FL. Longitudinal parasitological data for two species that are of major economic importance in cattle, Ostertagia ostertagi and Cooperia oncophora, were obtained from seven cattle farms in Belgium for model validation. The framework replicated the observed seasonal dynamics of infection in cattle on these farms and overall, there was no evidence of systematic under- or over-prediction of faecal egg counts. However, the model under-predicted the faecal egg counts observed on one farm with very young calves, highlighting potential areas of uncertainty that may need further investigation if the model is to be applied to young livestock. The model could be used to drive further research into alternative parasite control strategies such as vaccine development and novel treatment approaches, and to understand gastrointestinal nematode epidemiology under changing climate and host management.

Removal of adult cyathostomins alters faecal microbiota and promotes an inflammatory phenotype in horses.

The interactions between parasitic helminths and gut microbiota are considered to be an important, although as yet incompletely understood, factor in the regulation of immunity, inflammation and a range of diseases. Infection with intestinal helminths is ubiquitous in grazing horses, with cyathostomins (about 50 species of which are recorded) predominating. Consequences of infection include both chronic effects, and an acute inflammatory syndrome, acute larval cyathostominosis, which sometimes follows removal of adult helminths by administration of anthelmintic drugs. The presence of cyathostomins as a resident helminth population of the equine gut (the "helminthome") provides an opportunity to investigate the effect helminth infection, and its perturbation, has on both the immune system and bacterial microbiome of the gut, as well as to determine the specific mechanisms of pathophysiology involved in equine acute larval cyathostominosis. We studied changes in the faecal microbiota of two groups of horses following treatment with anthelmintics (fenbendazole or moxidectin). We found decreases in both alpha diversity and beta diversity of the faecal microbiota at Day 7 post-treatment, which were reversed by Day 14. These changes were accompanied by increases in inflammatory biomarkers. The general pattern of faecal microbiota detected was similar to that seen in the relatively few equine gut microbiome studies reported to date. We conclude that interplay between resident cyathostomin populations and the bacterial microbiota of the equine large intestine is important in maintaining homeostasis and that disturbance of this ecology can lead to gut dysbiosis and play a role in the aetiology of inflammatory conditions in the horse, including acute larval cyathostominosis.

Proteolytic and nematicidal potential of the compost colonized by Hypsizygus marmoreus.

Spent mushroom compost (SMC) is a residue generated in edible mushrooms production, such as Hypsizygus marmoreus. Its genome was recently sequenced, demonstrating cuticle-degrading protease genes. The present work aims to investigate the proteases from H. marmoreus spent mushroom compost (SMC) by verifying its action on nematode larvae. The extraction of the crude extract directly with water from H. marmoreus SMC proved to be efficient for proteases obtainment, with proteolytic activity of 195.36 ±â€¯18.38 U g-1 of compound. Moreover, the zymogram and SDS-PAGE indicated the presence of two proteases with estimated molecular weights of 30.2 and 33.7 kDa. Due to the protease activity present in H. marmoreus SMC extract, there was a significant reduction in the number of Panagrellus redivivus and L3 in treated group compared to control group (p < 0.01), with 52% and 26% of reduction, respectively. A0A151VWY3 mature protein is composed of 296 amino acid residues, exhibiting molecular weight and pI of 29.5 kDa and 6.72. A0A151WD28 mature protein is composed of 343 amino acid residues, exhibiting molecular weight and pI of 34.4 kDa and 8.04. In the present work it was demonstrated that SMC from H. marmoreus has easily extracted protease content, presenting two proteases, possibly with cuticle-degrading activity, which had significant nematicidal effect on P. redivivus and bovine infective larvae.

Isolation and growth inhibition potential of entomopathogenic nematodes against three public health important mosquito vectors.

The prevalence of mosquito vector borne diseases and the resistance of mosquitoes to conventional pesticides have been of important public concern to the mosquito endemic countries. Present study was conducted to identify the native bio-larvicidal potential of the entomopathogenic nematodes; Steinernema siamkayai (KPR-4) Heterohabditis indica (KPR-8), Steinernema glaseri and Steinernema abbasi. The isolated nematodes were subsequently cultured and evaluated their larvicidal potential against the larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. Among the tested four different nematode species, the S. abassi exerted the highest mortality against A. aegypti (97.33%), the H. indica (KPR-8) against A. stephensi (97.33%) and the S. siamkayai (KPR-4) against C. quinquefasciatus (98.67%). The maximal mosquito-larvicidal property of EPNs was found with the LC50 and LC90 values (IJs/larvae): S. abbasi = 12.47 & 54.35 on A. aegypti; H. indica KPR-8 = 19.88 & 66.81 on A. stephensi and S. siamkayai KPR-4 = 16.69 & 58.97 on C. quinquefasciatus, respectively. The presently generated data on the molecular and larvicidal characteristics of the entomopathogenic nematodes form an important baseline data that upon further research would lead to the development of eco-friendly mosquito-control agent.

High prevalence and intensity of Stephanurus dentatus in a population of wild boar (Sus scrofa) in south western Spain.

In the period from October 2016 to February 2017, the urinary tracts of 390 wild boar (Sus scrofa) from four areas of south central Spain (102 from Doñana National Park; 150 from Sierra Morena and the Toledo Mountains; 84 from Sierra Nevada; 54 from Sierra de Cazorla, Segura y Las Villas Natural Park) were examined for the presence of adult specimens of Stephanurus dentatus (Nematoda: Strongyloidea). This parasite was only detected in the wild boar population of Doñana National Park, with high prevalence (76.5±4.2%; 78/102), mean intensity (43.2±4.4) and mean abundance (33.1±3.8). Juvenile wild boar had significantly lower prevalence and abundance than subadult and adult wild boar. The intensity of infestation was significantly higher in male than in female wild boar. The detection of a focus of S. dentatus infestation in the wild boar population in Doñana National Park will provide further opportunities for understanding the epidemiology of this parasite.

Equine strongyle communities are constrained by horse sex and species dipersal-fecundity trade-off.

BACKGROUND: Equine strongyles are a major health issue. Large strongyles can cause death of horses while cyathostomins (small strongyles) have shown increased resistance to anthelmintics worldwide. Description of strongyle communities have accumulated but little is known about the diversity of these communities and underpinning environmental factors. METHODS: Strongyles were recovered after ivermectin treatment from 48 horses located in six premises in Poland. Correlation between previously published species fecundity and the observed relative abundance and prevalence were estimated. Significance of horse sex was determined at the species level (prevalence, relative abundance) and at the community level (species richness and dissimilarity between communities). RESULTS: Strongyle species fell into two groups, contrasted by their prevalence and relative abundance. Six to nine horses were necessary to sample at least 90% of strongyle community diversity, providing a minimal cut-off to implement sampling trial in the field. Strongyle communities entertained a network of mostly positive interactions and species co-occurrence was found more often than expected by chance. In addition, species fecundity and prevalence were negatively correlated (Pearson's r = -0.71), suggesting functional trade-offs between species dispersal abilities and fecundity. This functional trade-off may underpin species coexistence. Horse sex was also a significant constraint shaping strongyle communities. Indeed, mares generally displayed more similar strongyle communities than stallions (P = 0.003) and Cylicostephanus calicatus was more abundant in stallions suggesting sex-specific interactions (P = 0.006). CONCLUSIONS: While niche partitioning is likely to explain some of the positive interactions between equine strongyle species, coexistence may also result from a functional trade-off between dispersal ability and fecundity. There is significant evidence that horse sex drives strongylid community structure, which may require differential control strategies between mares and stallions.

Risk factors associated with strongylid egg count prevalence and abundance in the United States equine population.

Equine strongyle parasites are considered ubiquitous in grazing equids across the world, and cyathostomin parasites are known pathogens causing well-described disease complexes in horses. Decades of intensive anthelmintic treatments have led to anthelmintic resistance in cyathostomins, and current recommendations are to lower treatment intensity and base control strategies on fecal egg count surveillance. Little is known about risk factors associated with strongyle parasite egg shedding patterns in the United States equine population, as the most recent national survey was conducted 20 years ago. The present study was carried out as part of the National Animal Health Monitoring Systems (NAHMS) Equine 2015-2016 study. The aims were to describe strongyle parasite egg shedding patterns in the United States equine population and identify risk factors associated with prevalence and egg count magnitude. Data were collected from equine operations in 28 states via questionnaires and fecal samples submitted to a parasitology research laboratory for fecal egg count analysis and the data gathered underwent comprehensive statistical analyses. Though region and season were related, overall, the summer months and the fall in the southeast tended to have the greatest odds of presence of strongyles eggs on a FEC. Generally, equids resident in the Western region (Arizona, California, Colorado, Montana, Oregon, and Wyoming) had significantly lower strongyle prevalence, no matter the season, as well as a markedly different distribution between strongyle egg shedding levels (p = 0.0005). Overall, egg counts were over-dispersed with about 27% of equids (95% Confidence Interval (CI): 20-34%) contributing 80% of the egg output. Pasture history was significantly associated with strongyle egg prevalence (p = 0.0003) and egg shedding levels (p = 0.0063) with daily access in the previous 30 days being associated with higher odds of presence and greater median egg count levels. Equid gender was significantly associated with strongylid presence (p = 0.0081) and egg count level (p = 0.0008), with male equids having significantly lower odds and median egg counts than female equids, and age was significantly negatively associated with strongylid prevalence (p < 0.0001). Time since last deworming was significantly positively associated with prevalence of strongyle eggs, and this was dependent on the class of dewormer used (p = 0.0086), with equids treated with macrocyclic lactone class of drugs having lower odds of strongyle egg presence at 120 days since the last deworming. These data provide useful insights into strongylid egg shedding patterns in the United States equine population, and they can help refine parasite control recommendations depending on region, pasture access, and age distribution.

Mammomonogamus nematodes in felid carnivores: a minireview and the first molecular characterization.

Five of the 13 known species of Mammomonogamus have been described in members of the family Felidae, including domestic cats, making felids the most frequent hosts of Mammomonogamus. The occurrence of Mammomonogamus in felids is geographically scattered and information on the life cycle and other aspects of infections is lacking. The paucity of data opens the questions on possible conspecificity of some of the described species of Mammomonogamus and on the existence of possible reservoirs for infections in domestic cats in geographically isolated endemic foci of infection. To test such hypotheses, we compared sequences of mitochondrial and nuclear markers obtained from Mammomonogamus adults or eggs collected from domestic cats in three geographically distant localities. Based on morphology, geographic origin and site of infection, the worms examined can be referred to as Mammomonogamus ierei and Mammomonogamus auris. Phylogenetic analyses of both mitochondrial and ribosomal DNA markers showed monophyly of the genus Mammomonogamus and suggested the existence of at least two species in cats. Review of the literature, the existence of several species and the discontinuous geographic distribution of Mammomonogamus infections in domestic cats suggest an historical spillover of infection from wild reservoirs, presumably wild felids.

Occurrence of gastrointestinal parasites in wild animals in State of Paraná, Brazil

ABSTRACT The objective of this study was to determine the prevalence and diversity of gastrointestinal parasites in fecal samples from wild birds and mammals from the State of Paraná. In total, 220 stool samples were sent to Parasitic Diseases Laboratory of the Federal University of Paraná during 13 months (Jan/2013-Jan/2014). A total of 52.7% (116/220) of the animals were positive for cysts, oocysts, eggs and/or trophozoites. In birds, the positivity rate was 37.9% (25/66) and mammals was 59.1% (91/154). Strongyloidea superfamily eggs were observed in 37.3% (82/220) of the samples, Eimeria spp. in 10% (22/220), and Trichuris spp. in 4.5% (10/220). The most frequent mammal species were llamas (Lama glama), and dromedaries (Camelus bactrianus) with infection rate of 70.1% (54/77) and 60.8% (14/23), respectively. In other hand, cockatiels (Nymphicus hollandicus) and ring necks (Psittacula krameri), were the most researched birds, with infection rate of 20% (40/50) and 100% (6/6), respectively. A high prevalence of gastrointestinal parasites was observed in most of wildlife animals. Further investigations should be conducted focusing on parasite control strategies and the conservation measurements for harmonizing the human-animal interaction on the long-term, reducing associated health risks.

Diversity of Mammomonogamus (Nematoda: Syngamidae) in large African herbivores.

Four species of Mammomonogamus are known from large African herbivores. A recent study demonstrated that a single Mammomonogamus species was shared by both western lowland gorillas (Gorilla gorilla gorilla) and African forest elephants (Loxodonta cyclotis) in Central African Republic, suggesting lower species diversity than previously described in literature. We examined more than 500 fecal samples collected from sympatric African forest elephants, western lowland gorillas, and African forest buffaloes (Syncerus caffer nanus) at four study sites across Central Africa and examined them by coproscopic methods to detect Mammomonogamus eggs, which were found at three of the study sites. Subsequently, sequences of 18S rDNA, 28S rDNA, and cox1 amplified from individual eggs were analyzed. Phylogenetic analyses of both nuclear and mitochondrial DNA revealed two clades: one formed by sequences originating from Gabonese buffaloes and the other comprising gorillas and elephants. The gorilla-elephant clade was further differentiated depending on the locality. We show the existence of at least two distinct species of Mammomonogamus, M. loxodontis in elephants and gorillas and M. nasicola in buffaloes. The available information on Mammomonogamus in African herbivores is reviewed.

Occurrence of gastrointestinal parasites in wild animals in State of Paraná, Brazil.

The objective of this study was to determine the prevalence and diversity of gastrointestinal parasites in fecal samples from wild birds and mammals from the State of Paraná. In total, 220 stool samples were sent to Parasitic Diseases Laboratory of the Federal University of Paraná during 13 months (Jan/2013-Jan/2014). A total of 52.7% (116/220) of the animals were positive for cysts, oocysts, eggs and/or trophozoites. In birds, the positivity rate was 37.9% (25/66) and mammals was 59.1% (91/154). Strongyloidea superfamily eggs were observed in 37.3% (82/220) of the samples, Eimeria spp. in 10% (22/220), and Trichuris spp. in 4.5% (10/220). The most frequent mammal species were llamas (Lama glama), and dromedaries (Camelus bactrianus) with infection rate of 70.1% (54/77) and 60.8% (14/23), respectively. In other hand, cockatiels (Nymphicus hollandicus) and ring necks (Psittacula krameri), were the most researched birds, with infection rate of 20% (40/50) and 100% (6/6), respectively. A high prevalence of gastrointestinal parasites was observed in most of wildlife animals. Further investigations should be conducted focusing on parasite control strategies and the conservation measurements for harmonizing the human-animal interaction on the long-term, reducing associated health risks.

Applicability of FLOTAC® technique in recovering equine strongyle larvae in the pasture: A comparison study.

The FLOTAC® technique represents a highly sensitive method for the isolation of oocysts, eggs, and larvae of parasites in faeces. This assay could be used for detecting free-living stages of nematodes in the pasture but no attempt has been assessed so far. Therefore, the performance of FLOTAC® technique for isolating infective larvae of nematodes in the environment was investigated and compared with the spontaneous sedimentation (SST) and centrifugal sedimentation (CST) techniques. The study was conducted in a horse farm located in northeastern Brazil, where the occurrence of strongyle larvae had been previously reported. Pasture samplings were collected monthly from January to May 2016 in a 376 m2 crop area harvested with the Guinea grass Panicum cultivar Massai. The recovery of third-stage larvae (L3) was performed using the FLOTAC®, SST and CST techniques. Values of Cohen's kappa coefficient, sensitivity, specificity, positive and negative predictive values, and accuracy of each technique were assessed. Although strongyle larvae were evenly detected, with the FLOTAC® technique yielded the highest number of positive samples (i.e., 41%, 41/100, p < .0001). The main parasites isolated belonged to the Cyathostominae and Strongylinae subfamilies. Based on these results, the FLOTAC® technique should be considered as practical and safe method for the isolation of nematode larvae in the pasture, thus opening a new potential use for this tool in the field.

Cyathostomine egg reappearance period following ivermectin treatment in a cohort of UK Thoroughbreds.

BACKGROUND: In spite of the emergence of populations of drug-resistant cyathostomines worldwide, little is known of parasite species responsible for 'early egg shedding' in cohorts of horses subjected to treatment with widely used anthelmintics, e.g. ivermectin (IVM). In this study, we determined the cyathostomine egg reappearance period (ERP) after IVM treatment in a cohort of yearlings from a large Thoroughbred (TB) stud farm in the United Kingdom, and identified species of cyathostomines with reduced ERP using a combination of fundamental parasitology techniques coupled with advanced molecular tools. METHODS: Individual faecal samples were collected from TB yearlings with cyathostomine infection prior to IVM treatment, as well as at 14, 21, 28, 35, 42 and 49 days post-treatment. Faecal egg counts (FEC) were performed for each individual sample for determination of ERPs. In addition, individual larval cultures were performed and representative numbers of third-stage larvae (L3s) harvested from each culture were subjected to molecular species identification via PCR-Reverse Line Blot (RLB). RESULTS: Prior to IVM treatment, 11 cyathostomine species were detected in faecal samples from TB horses enrolled in this study, i.e. Cyathostomum catinatum, Cylicostephanus longibursatus, Cylicostephanus goldi, Cylicocyclus nassatus, Cylicostephanus calicatus, Cyathostomum pateratum, Cylicocyclus radiatus, Paraposteriostomum mettami, Coronocyclus labratus, Cylicocyclus insigne and Cylicocyclus radiatus variant A. Of these, eggs of Cya. catinatum, Cys. longibursatus, Cyc. nassatus and Cyc. radiatus could be detected at 28 days post-treatment, while from day 42 onwards, cyathostomine species composition reflected data obtained pre-IVM treatment, with the exception of eggs of Cor. labratus and Cyc. insigne which could no longer be detected post-IVM administration. CONCLUSIONS: This study provides valuable data on the occurrence of IVM-resistance in cyathostomines in the UK. Nevertheless, further investigations are needed to shed light on the prevalence and incidence of drug-resistance in this country, as well as other areas of the world where equine trade is substantial.

Cyathostomin faecal egg counts in horse farms from Central Italy.

Cyathostomins,  or  'small  strongyles',  are  the  most  important  equine  helminths  because  of their  worldwide  distribution,  spread  of  anthelmintic­resistant  populations,  and  pathogenic impact.  The  so­called  'selective  treatment'  of  those  animals  exceeding  a  certain  faecal  egg  count  (FEC)  has  recently  been  proposed  to  implement  cyathostomin  control  programmes.  The present study evaluated the extent of egg shedding in 475 horses living in 12 farms from 3 regions of Italy. All examined farms and 224 horses (47.6%) were positive for cyathostomins. 138 horses (28.8%) scored positive for cyathostomin FECs with a range of eggs­per­gram of faeces (epg) values of 50­2,150. Further 86 horses (18.1%) were positive only under qualitative microscopy (i.e. < 50 epg). Of the animals with a FEC > 50 epg, 81 (17%) and 57 (12%) showed values  of  50­200  and  >  200  epg,  respectively.  The  findings  from  this  study  demonstrated  a reduced presence of high­shedding horses compared to results obtained in previous years in  the  same  study  areas,  despite  overlapping  climate  features  in  the  previous  5  years.  A  continuing  monitoring  of  epidemiological  and  biological  features  of  horse  cyathostomin infection  is  crucial  for  planning  intervention  programmes  aimed  to  maintaining  animal health and preserving the efficacy of parasiticides.