The oral application of chlamydospores of the nematophagous fungus Duddingtonia flagrans allows reducing the number of infective larvae (L3) in faeces and decreases the infectivity of the pastures of ...gastrointestinal nematodes. There are differences in the literature about the quantity of chlamydospores required for the reduction of L3 and there is little data about the importance of the concentration of parasite eggs in faeces in relation to the predatory effect of fungus. This study evaluated the reduction of L3 in faeces taking into account four concentrations of chlamydospores of D. flagrans with four concentrations of faecal eggs per gram (epg). Two hundred coprocultures were performed with 10 g each one, using faeces from four parasitised sheep with natural infections. The coprocultures were distributed in treated groups (GT) containing 180, 620, 1460 and 3600 epg along with 1000, 6250, 3000 and 11,000 chlamydospores per gram of faeces. Four control groups without chlamydospores were performed for each GT. The coprocultures were incubated for 16 days at room temperature of 27°C. The reduction percentages for the group of 11,000 chlamydospores and epg 180, 620, 1460 and 3600 were 6.51%; 1.35%; 52% and 85%, respectively. In the group of 6250 chlamydospores the reduction percentages for epg 180, 620, 1460 and 3600 were 16%; 20%; 66% and 67%, respectively. These results would indicate that the predatory capacity of D. flagrans can be dependent on the stimulus generated by the presence of larvae as well as the concentration of chlamydospores present in the faeces.
The purpose of using nematophagous fungi as biological control agents of gastrointestinal nematodes of livestock is to reduce the build-up of infective larvae on pasture and thus avoid clinical and ...subclinical disease. As the interaction of fungus-larval stages takes place in the environment, it is crucial to know how useful the fungal agents are throughout the seasons in areas where livestock graze all year-round. This study was designed to determine the predatory ability of the nematophagous fungus
against gastrointestinal nematodes of cattle during four experiments set up in different seasons. In each experiment, faeces containing eggs of gastrointestinal nematodes were mixed with 11,000 chlamydospores/g and deposited on pasture plots. A comparison between fungal-added faeces and control faeces without fungus were made with regard to pasture infectivity, larval presence in faecal pats, faecal cultures, faecal pat weight, and temperature inside the faecal mass. In three of the four experiments,
significantly reduced the population of infective larvae in cultures (68 to 97%), on herbage (80 to 100%), and inside the faecal pats (70 to 95%). The study demonstrated the possibility of counting on a biological control tool throughout most of the year in cattle regions with extensive grazing seasons.
Nematophagous fungi are a biological control tool used against gastrointestinal nematodes in livestock. These fungi prey on free-living larvae in faeces and could be affected by active drugs excreted ...post-treatment. This study aimed to determine in vitro and under environmental conditions the effect of the following anthelmintics on the fungus Duddingtonia flagrans: ivermectin, levamisole, albendazole, fenbendazole and ricobendazole. The in vitro effect of anthelmintics on fungal growth and predatory capacity was assessed in corn meal agar and coprocultures, respectively. Ivermectin (1, 2 and 10 ppm), fenbendazole (0.027, 0.054 and 1 ppm) and albendazole (1 ppm) significantly affected fungal development. The fungal efficacy against L3 was high in the control and levamisole coprocultures but decreased significantly in the presence of albendazole, fenbendazole, ricobendazole and ivermectin. The impact of levamisole on D. flagrans was further assessed under environmental conditions in autumn and winter; the fungal efficacy measured in faecal pats and the surrounding herbage was not affected by levamisole at any time. This study shows that using albendazole, fenbendazole, ricobendazole or ivermectin may compromise fungal activity, as these drugs affect the free-living stages of nematodes in faeces, but levamisole can be safely considered in parasite control strategies involving D. flagrans and anthelmintic treatments.
Duddingtonia flagrans is a natural strain of Nematophagous-Fungi isolated around the world. It has demonstrated efficacy and ease of use in laboratory as well as in field conditions. The fungus ...contributes to the prophylactic control of the worms by reducing the number of L3 on pasture. The aims of this study were to test and analyze the predatory effect of D. flagrans under sunny and shaded conditions on the L3 in the faeces, and to verify the reduction of translation to pasture during summer and winter seasons. Faecal Mass Units (FMUs) were assigned to two treated groups (groups treated with D. flagrans chlamydospores, TG) and two untreated groups (without D. flagrans chlamydospores, UG), in summer and winter, under sunny and shaded conditions. FMUs and herbage samples were taken for parasitological workup. Predatory activity of D. flagrans was evident under both conditions for the summer experiment but was not manifest for the winter experiment. In summer, an interaction between sunny and shaded conditions and predatory activity of D. flagrans was found. Environmental conditions on predatory activity should be considered when designing strategies for the implementation of D. flagrans in grazing systems to smooth the infectivity curve of L3.
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•The aim was to test Duddingtonia flagrans under different environmental conditions.•Predatory activity of Duddingtonia flagrans was evident in summer.•Predatory activity of Duddingtonia flagrans was not manifest in winter.•Predatory activity of D. flagrans was affected by the environment conditions.
In horses, the nematodes of the Strongylidae family are the most important due to their prevalence and pathogenicity. Sanitary plans include parasite control based on chemical anthelmintics. Among ...these, the benzimidazole compounds have been used since the 1960s to control the nematode
Strongylus vulgaris
. Its inappropriate use resulted in the development of resistance in parasites with a shorter biological cycle, such as the small strongyles. Currently, the genera that make up this group show widespread resistance to all chemical treatments available in veterinary medicine, except for macrocyclic lactones, where less effective action has been detected. The need to find alternative routes for its control is recognized. International organizations and markets are increasingly restrictive in the allowed levels of drugs in products of animal origin, so one of the drawbacks is the permanence of chemical compounds in tissues. Therefore, other tools not chemically based are proposed, such as the biological control of gastrointestinal nematodes. Various research groups around the world have carried out tests on the control capacity of the nematophagous fungus
Duddingtonia flagrans
against this group of parasites. The objective of this review is to compile the different tests that are available on biological control in this species, in in vivo and in vitro tests, and the possible incorporation of this tool as an alternative method of antiparasitic control in an integrated control scheme of parasites.
The nematophagous fungus Duddingtonia flagrans, used for the biological control of gastrointestinal nematodes in livestock, is fed to infected animals so its chlamydospores and the parasite eggs are ...voided together with faeces where the fungus preys on nematode larvae, thus reducing pasture infectivity. The number of chlamydospores needed for the fungus to be efficient in the presence of a wide range in numbers of parasitic eggs is largely unknown and a matter of discussion. The aim of this study was to determine the fungal efficacy of four different chlamydospore concentrations against three different levels of cattle faecal egg counts. Fungal concentrations of 11000, 6250, 3000 and 1000 chlamydospores/gram of faeces (cpg) were added to cultures containing 840, 480 or 100 eggs/gram of faeces (epg). After 14 days of incubation, the efficacy of D. flagrans, in decreasing order of chlamydospore concentrations, ranged from 100% (P < 0.0001) to 77% (P > 0.0999) in the 100 epg groups; 100% (P < 0.0001) to 92% (P = 0.4625) in the 480 epg groups and 100% (P < 0.0001) to 96% (P = 0.7081) in the 840 epg groups. The results indicate that the numbers of eggs in cattle faeces were not a determining factor on the fungal efficacy against gastrointestinal nematodes.
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•Duddingtonia flagrans efficacy confirmed regardless of levels of faecal egg counts.•Fungal concentration is not crucial for high efficacy against cattle nematodes.•Nematode eggs:chlamydospores ratio is not relevant for fungal predatory activity.•Fungal ‘dose’ based on faecal egg counts does not need to be adjusted for cattle.
Digitalization and automation in the agricultural sector enable the enhancement of production processes, leading to increased yields. Specifically, the medications administration or complementary ...treatments in animals often prove to be a demanding task for human operators. This letter introduces an embedded system prototype that facilitates monitoring the level of capsules coverage in troughs through image processing. The suggested system enables an innovative antiparasitic treatment using biological control agents. The prototype utilizes a Raspberry Pi 3B as the platform to execute the developed image processing algorithm. The obtained results successfully demonstrate the algorithm's accurate functionality estimating capsules coverage within the troughs.
The aim of this work was to evaluate the fate of ivermectin (IVM) at two concentrations in cattle feces and its movement to the nearby soil and plants. Feces were spiked with IVM at two levels: ...3000 ng g
−1
(high group, HG) and 300 ng g
−1
(low group, LG). Artificial dung pats were prepared and deposited in an experimental field area. Feces and underlying soil were sampled up to 60 days post-deposition (dpd). As an additional analysis, grasses growing around the pats were sampled at 30 and 60 dpd. Ivermectin concentrations in all matrices were determined by HPLC. Mean IVM fecal concentrations were in the range between 3901.9 ng g
−1
and 2419.2 ng g
−1
(high group) and 375.3 ng g
−1
and 177.49 ng g
−1
(low group). Mean times for 50% and 90% dissipation were 88.23 and 293.03 days (HG) and 39.1 and 129.9 days (LG). Soil concentrations ranged from 26.1 ng g
−1
to 71.1 ng g
−1
(HG) and 3.4 to 5.9 ng g
−1
(LG); in plants, concentrations were between 71.4 and 380.8 ng g
−1
and 5.40 and 51.8 ng g
−1
in HG and LG, respectively. These results confirm that IVM moves from feces to the underlying soil as well as to nearby plants. The potential risk of detrimental effects on soil organisms and the impact on herbivorous animals should be further evaluated.
Un control parasitario eficiente permite reducir pérdidas significativas en la agroindustria. Los métodos actuales con los que se realiza este tipo de controles imponen costos y demoras. Por ello, se ...propone el desarrollo de un dispositivo portátil que automatice esta tarea. En este trabajo se presenta la implementación hardware de un algoritmo de conteo automático de huevos de parásitos utilizando síntesis de alto nivel. Los resultados demuestran la factibilidad de la implementación, con un 87% de precisión operando a una tasa de hasta de 65 frames por segundo y una ocupación de LUTs menor al 45%, considerando dos kits comerciales (PYNQ-Z1 y ULTRA96V2).
•Ivermectin efficacy was higher after oral compared to the intramuscular treatment.•Ivermectin plasma concentrations were greater after intramuscular administration.•The oral treatment increased the ...drug exposure of the gastrointestinal nematodes.
The goal of the current study was to evaluate the comparative efficacy of ivermectin (IVM) against small strongyles (cyathostomins) following its oral and intramuscular (IM) administration, in naturally parasitized horses. The parasitological data were complemented with the assessment of the plasma disposition kinetics of IVM. The trial included two different experiments. In experiment I, 40 horses naturally infected with small strongyles were randomly allocated into four experimental groups (n=10) and treated with IVM (0.2mg/kg) as follows: IVM oral paste, animals were orally treated with Eqvalan® (IVM 1.87% paste, as the reference formulation) by the oral route; IVM oral solution, animals were orally treated with Remonta® (IVM 2% solution, as a test formulation); IVM IM solution, animals were IM treated with the test product (Remonta® IVM 2% solution); and control, animals were kept without treatment as untreated controls. In experiment II, 24 horses naturally parasitized with small strongyles were randomly allocated into the same four experimental groups (n=6) described for experiment I. Faecal samples were individually collected directly from the rectum of each horse prior (day −1) and at 7 and 15 (Experiment I) or 7, 15 and 21 (Experiment II) days after-treatment, to assess the eggs per gram (epg) counts and estimate the efficacy of the treatments. Additionally, the comparative plasma disposition kinetics of IVM in treated animals was assessed in experiment II. In both experiments, an excellent (100%) IVM efficacy was observed after its oral administration (test and reference formulations). However, the IM administration of IVM resulted in a low efficacy (36–64%). Similar IVM plasma concentration was observed after its oral administration as a paste or as a solution. The higher IVM plasma profiles observed after the IM administration accounted for an enhanced systemic availability. The improved IVM efficacy observed against adult cyathostomins after its oral administration can be explained by an enhanced drug exposure of the worms located at the lumen of the large intestine. These findings may have a direct impact on the practical use of macrocyclic lactones in horses.
