Duddingtonia flagrans and its crude proteolytic extract: concomitant action in sheep coprocultures.

The presence of infective larvae (L3) of gastrointestinal nematode (GIN) parasites in pastures directly contributes to the constant recurrence of infections in ruminant herds. This study aimed to evaluate the nematophagous fungus Duddingtonia flagrans (AC001) (proteolytic crude extract and/or conidia) in the in vitro control of GIN L3 in coprocultures. To produce the proteolytic crude extract, a suspension (107 conidia/mL) of D. flagrans was inoculated into a liquid medium. After 6 days, the medium was filtered, centrifuged, and its proteolytic activity was measured. For the experimental assay, fecal samples were collected directly from the rectal ampulla of naturally infected sheep, and egg counts per gram of feces (EPG) were performed. Coprocultures were prepared using 10 g of fecal material with the groups defined as follows: control group G1 (1.0 mL of denatured proteolytic crude extract); treated group G2 (1.0 mL of active proteolytic crude extract); treated group G3 (1.0 mL of active proteolytic crude extract + 1.0 mL of AC001 conidia). The coprocultures were maintained at room temperature (25ºC), for 7 days, and then the L3 larvae were recovered. The results demonstrated that AC001 successfully produced protease (56.34 U/mL). The treatments with active proteolytic crude extract (G2) and active proteolytic crude extract + AC001 conidia (G3) were significantly different (p < 0.01) from the control group with denatured proteolytic crude extract (G1). AC001 and its proteolytic crude extract acted concomitantly on helminths directly in the fecal environment, suggesting potential future applications in the field.

Efficacy Evaluation of a Commercial Formulation With Duddingtonia Flagrans in Equine Gastrointestinal Nematodes.

The indiscriminate use of antiparasitics for the treatment of helminths in horses has caused the ineffectiveness of commonly used chemical active principles, therefore, new alternatives such as the use of helminthophagous fungi have been studied. In this context, this study aimed to evaluate the in vitro efficacy of the commercial formulation Bioverm, composed of the fungus Duddingtonia flagrans strain AC001, in the reduction of gastrointestinal nematode larvae in equine feces. In coproculture, the genus Cyathostomum sp. was the most prevalent in the analyzed samples. The commercial formulation with D. flagrans demonstrated effectiveness in the predation of Cyathostomum sp. in tests. The recommended dose of 0.4 g, containing 105 chlamydospores per gram of product, reduced larvae by 44.23%, while the extrapolated dose of 1.0 g with the same concentrations of chlamydospores (105/g) resulted in a reduction of 57.20%, indicating the effectiveness of the product in controlling infective larvae.

Complementary Approaches with Free-living and Parasitic Nematodes to Understanding Anthelmintic Resistance.

Anthelmintic drugs are the major line of defense against parasitic nematode infections, but the arsenal is limited and resistance threatens sustained efficacy of the available drugs. Discoveries of the modes of action of these drugs and mechanisms of resistance have predominantly come from studies of a related nonparasitic nematode species, Caenorhabditis elegans, and the parasitic nematode Haemonchus contortus. Here, we discuss how our understanding of anthelmintic resistance and modes of action came from the interplay of results from each of these species. We argue that this 'cycle of discovery', where results from one species inform the design of experiments in the other, can use the complementary strengths of both to understand anthelmintic modes of action and mechanisms of resistance.

Multimodal imaging-guided diagnosis, management and follow-up of a case of diffuse unilateral subacute neuroretinitis.

A 45-year-old woman presented with diminished vision in the left eye. Visual acuity was 6/9 and fundus showed a very large live nematode near the macula along with inflammatory outer retinal lesions in the periphery. We diagnosed the case as diffuse unilateral subacute neuroretinitis and treated with immediate focal photocoagulation of the worm along with oral antihelminthic drugs and corticosteroids. The report highlights the importance of prompt laser and steroids in achieving good structural as well as the functional outcome, and the added significance of advanced imaging techniques in prognosticating such patients.

Microbiome analysis as a platform R&D tool for parasitic nematode disease management.

The relationship between bacterial communities and their host is being extensively investigated for the potential to improve the host's health. Little is known about the interplay between the microbiota of parasites and the health of the infected host. Using nematode co-infection of lambs as a proof-of-concept model, the aim of this study was to characterise the microbiomes of nematodes and that of their host, enabling identification of candidate nematode-specific microbiota member(s) that could be exploited as drug development tools or for targeted therapy. Deep sequencing techniques were used to elucidate the microbiomes of different life stages of two parasitic nematodes of ruminants, Haemonchus contortus and Teladorsagia circumcincta, as well as that of the co-infected ovine hosts, pre- and post infection. Bioinformatic analyses demonstrated significant differences between the composition of the nematode and ovine microbiomes. The two nematode species also differed significantly. The data indicated a shift in the constitution of the larval nematode microbiome after exposure to the ovine microbiome, and in the ovine intestinal microbial community over time as a result of helminth co-infection. Several bacterial species were identified in nematodes that were absent from their surrounding abomasal environment, the most significant of which included Escherichia coli/Shigella. The ability to purposefully infect nematode species with engineered E. coli was demonstrated in vitro, validating the concept of using this bacterium as a nematode-specific drug development tool and/or drug delivery vehicle. To our knowledge, this is the first description of the concept of exploiting a parasite's microbiome for drug development and treatment purposes.

Evaluation of Parasitological Homeopathic Complex in the Control of Gastrointestinal Nematodes in Peripartum Sheep.

BACKGROUND: The appearance of anthelmintic resistance has made it difficult to control verminosis in sheep, leading to increased research to find alternative nematode control. The use of homeopathy in veterinary medicine has been studied as an alternative for the treatment and control of some diseases. In this study, ewes received an anti-parasitic homeopathic complex medicine during the critical peripartum period of increased susceptibility to nematodes. METHODS: Three randomized groups containing 16 animals each were assigned as follows: 'H10' received 10 g homeopathic complex added to concentrated food per day; 'H20' received 20 g homeopathic complex added to concentrated food per day; 'C' (control group) did not receive a homeopathic complex. Animals were tested to evaluate the effect of homeopathy on several health parameters during a period of 110 days. RESULTS: The parasite that prevailed in the copro-cultures of both treatments throughout the experiment was Haemonchus contortus (78.26%). Packed cell volume averages did not present statistically significant differences between the treatments (24.5, 24.4 and 23.9% to C, H10 and H20, respectively; p < 0.05). For total white cell count, lower mean values ( ± standard error of mean) were observed for the H20 treatment (5,490.9 ± 0.02/µL; p < 0.05), whereas the H10 (5,919.4 ± 0.02/µL) and control (6,098.5 ± 0.02/µL) presented higher and similar averages (p > 0.05). The values for erythrocytes, monocytes, and lymphocytes did not show differences between treatments (p > 0.05). Body weight was greater in the H10-treated animals compared with control. For the fecal egg count (FEC) of Trichostrongylidae and Strongyloides spp., respectively, the averages of the H20 treatment (1,523.0 and 30.6) were not different from control (1,616.0 and 31.6) and H10 (1,038.0 and 27.6); for Trichostrongylidae, however, H10 presented a lower FEC than the control (p = 0.02). For Cooperia, H10- and H20-treated animals showed FEC reductions of 97% and 98%, respectively. CONCLUSIONS: H20 treatment in peripartum sheep resulted in greater body weight and lower leukocyte count. H10 was associated with lower FEC for Trichostrongylidae. Both H10 and H20 justify a label of 'effective anthelmintic' for Cooperia.

Case report: a case of diffuse unilateral subacute neuroretinitis (DUSN) in a child.

BACKGROUND: Diffuse unilateral subacute neuroretinitis (DUSN) is a rare cause of posterior uveitis in the United Kingdom. It typically presents unilaterally in children and young adults but rarely bilateral cases have been reported. It is also rare to have multiple worms in the same eye causing the clinical picture. In this article, we present a challenging case of DUSN in a young girl unresponsive to conventional treatments suggesting the possibility of multiple worms being present in the same eye. CASE PRESENTATION: An 8-year-old girl presented with a 2-month history of headaches. On occasions the headaches were associated with redness and watering of her left eye. She denied any visual loss or visual symptoms. Her visual acuity was reduced to 6/30 in her left eye. Fundal examination revealed a unilateral chorioretinitis. Investigation did not reveal a specific cause for the chorioretinitis. Over 15 months her visual acuity improved to 6/9 but the fundal appearance changed and a diagnosis of DUSN was made. She was treated with focal laser, systemic anti-helminthic and immunosuppressive treatments but continued to develop new, active areas of chorioretinitis, raising the possibility of multiple worms in the sub-retinal space. There is also a concern as to other central nervous system (CNS) involvement given her significant and ongoing headaches. CONCLUSION: We present a challenging case of DUSN in a young girl; a condition that remains rare in the UK. She was unresponsive to both focal laser and systemic anti-helminthic and immunosuppressive treatments suggesting the possibility of multiple worms being present in the sub-retinal space. This case highlights the difficulties often encountered in the treatment of DUSN, even when a worm can be identified. Her visual prognosis is poor as there was ongoing recurrence of active chorioretinitis.

Field evaluation of Duddingtonia flagrans IAH 1297 for the reduction of worm burden in grazing animals: Pasture larval studies in horses, cattle and goats.

A series of placebo-controlled trials were conducted in horses, cattle and goats in different seasons and bioclimatic regions of New South Wales and Queensland, Australia, to evaluate the ability of BioWorma®, a feed supplement containing the spores of Duddingtonia flagrans IAH 1297, to reduce the larval development of parasitic gastrointestinal nematodes (GIN) and their subsequent migration from faeces onto the surrounding pasture. In each trial, faeces were collected from animals harbouring a burden of nematode parasites following a period of supplementation with a placebo and again after supplementation with BioWorma. The faeces were manually placed onto pasture plots at one or two distinct geographical sites and the effect of treatment was determined by subsequent monitoring the numbers of parasitic larvae on the pasture surrounding the faecal pats at two weekly intervals over an eight week period. The results for these studies showed that administration of BioWorma at a minimum daily dose of 3 × 104 spores/kg bodyweight reduced parasite larvae in the pasture surrounding the faeces by 53-99 % over an eight week post treatment period in horses, cattle and goats in a range of bioclimatic zones and in different seasons. Overall, the studies with BioWorma show substantial reductions in GIN infectivity of pasture surrounding faeces of treated horses, cattle and goats (P < 0.05). Results indicate that the use of BioWorma in these host species would lead to decreased levels of GIN infection in animals grazing pasture when this product is used and would provide an alternative means of controlling parasitic nematodes.

Coadministration of Nematophagous Fungi for Biological Control over Nematodes in Bovine in the South-Eastern Brazil.

This study compared the coadministration among the three nematode predatory fungi, Duddingtonia flagrans, Monacrosporium thaumasium, and Arthrobotrys robusta, in the biological control of cattle gastrointestinal nematodiasis in comparison with the use of the fungus D. flagrans alone. Five groups consisting of eight Girolando heifers were kept in paddocks of Brachiaria decumbens for six months. Each heifer received 1 g/10 kg of pellets containing the fungi (0.2 g of fungus/10 kg b.w.). Group 1 (G1) received pellets with D. flagrans and M. thaumasium in coadministration, G2 received D. flagrans and A. robusta, G3 received M. thaumasium, A. robusta, and D. flagrans, and G4 received the fungus D. flagrans alone. Group 5 (control) received pellets without fungi. The monthly mean of fecal egg count (FEC) of Groups 1, 2, 3, and 4 were 93.8, 85.3, 82.7, and 96.4% smaller than the mean of control group. The treatments with pellets containing D. flagrans or D. flagrans + M. thaumasium produced significantly better results than the D. flagrans + A. robusta or the combination of the three fungi. The associations which include A. robusta were less efficient in this study than D. flagrans alone or associated with M. thaumasium.

Control of sheep gastrointestinal nematodes using the combination of Duddingtonia flagrans and Levamisole Hydrochloride 5.

The objective was to evaluate the action of D. flagrans pellets in association with Levamisole Hydrochloride 5% for controlling sheep gastrointestinal nematodes in the northeastern Brazil. Three groups of six sheep each were formed: group 1 received 3 g of the pellets (0.6 g of D. flagrans mycelium) for each 10 kg b.w., twice a week for six months, and deworming with Levamisole Hydrochloride 5% when EPG ≥ 1500; group 2 received a dosage of Levamisole Hydrochloride 5% when EPG ≥ 1500; and group 3 received 3 g of pellets without fungi for each 10 kg b.w., twice a week for six months. EPG counts, larval cultures, packed cell volume (PCV) and weighing were performed every 15 days; monthly, samples of grass from each paddock were collected. The mean EPG of the groups began to statistically differ from day 30 (p < 0.05). Group 1 required less deworming with Levamisole Hydrochloride 5% and showed superiority of PCV values ​​throughout the experiment (p < 0.05). There was a significant reduction (p < 0.05) in L3 recovery in the group 1 paddock from day 30 onwards. The use of D. flagrans pellets in association with Levamisole Hydrochloride 5% was effective for controlling gastrointestinal nematodes.

Control of sheep gastrointestinal nematodes using the combination of Duddingtonia flagrans and Levamisole Hydrochloride 5% / Controle de nematódeos gastrintestinais de ovinos utilizando a combinação de Duddingtonia flagrans e Cloridrato de Levamisole 5%

Abstract The objective was to evaluate the action of D. flagrans pellets in association with Levamisole Hydrochloride 5% for controlling sheep gastrointestinal nematodes in the northeastern Brazil. Three groups of six sheep each were formed: group 1 received 3 g of the pellets (0.6 g of D. flagrans mycelium) for each 10 kg b.w., twice a week for six months, and deworming with Levamisole Hydrochloride 5% when EPG ≥ 1500; group 2 received a dosage of Levamisole Hydrochloride 5% when EPG ≥ 1500; and group 3 received 3 g of pellets without fungi for each 10 kg b.w., twice a week for six months. EPG counts, larval cultures, packed cell volume (PCV) and weighing were performed every 15 days; monthly, samples of grass from each paddock were collected. The mean EPG of the groups began to statistically differ from day 30 (p < 0.05). Group 1 required less deworming with Levamisole Hydrochloride 5% and showed superiority of PCV values ​​throughout the experiment (p < 0.05). There was a significant reduction (p < 0.05) in L3 recovery in the group 1 paddock from day 30 onwards. The use of D. flagrans pellets in association with Levamisole Hydrochloride 5% was effective for controlling gastrointestinal nematodes.

Resumo O objetivo foi avaliar a ação de péletes de Duddingtonia flagrans em associação ao Cloridrato de Levamisole 5% no controle de nematódeos gastrintestinais de ovinos no Nordeste do Brasil. Foram formados três grupos de seis animais cada: grupo 1 recebeu 3 g de péletes (0,6 g de micélio de D. flagrans) para cada 10 kg p.v., duaz vezes por semana durante seis meses, e vermifugações com Cloridrato de Levamisole 5% quando OPG > 1500; grupo 2 recebeu uma dosagem de Cloridrato de Levamisole 5% quando OPG ≥ 1500; e grupo 3 recebeu 3 g de péletes sem fungos para cada 10 kg de p.v., duas vezes por semana durante seis meses. Contagens de OPG, coproculturas, de volumes globulares (VG) e pesagens foram realizadas a cada 15 dias. Mensalmente, amostras de pasto de cada piquete eram coletadasa. A média de OPG dos grupos começou a diferir estatisticamente a partir do dia 30 (p < 0,05). O grupo 1 necessitou de menos vermifugações com Cloridrato de Levamisole 5% e demonstrou superioridade nos valores de VG durante todo o experimento (p < 0,05). Houve redução significativa (p < 0,05) nas L3 recuperadas no piquete do grupo 1 a partir do dia 30. Em conclusão, a utilização de péletes de D. flagrans em associação ao Cloridrato de Levamisole 5% foi eficaz no controle de nematódeos gastrintestinais de ovinos.

Controlling gastrointestinal nematodes in cattle by Bacillus species.

In this study, we tested the in vitro and in vivo larvicidal activity of Bacillus species against gastrointestinal nematodes in cattle, and their viability in the presence of anthelmintics. For in vitro tests, cattle feces naturally infected with trichostrongylides were incubated with spore suspensions of Bacillus circulans (Bcir), B. thuringiensis var. osvaldocruzi (Bto), B. thuringiensis var. israelensis (Bti) or B. thuringiensis var. kurstaki (Btk). Subsequently, residual larvae were counted and identified. All of the Bacillus species showed 60% or more larvicidal effects. Bcir and Bti were selected to be incubated with anthelmintics (moxidectin, nitroxynil and levamisole), and after 24, 72, and 144h, their viability was evaluated. Bti showed highest drug resistance, maintaining a concentration of 1×107CFU/mL. Based on this result, Bti was selected for in vivo tests on calves naturally infected with gastrointestinal nematodes. The calves were dived into four groups: Group 1, Bti suspension of ∼1×109CFU orally administered; Group 2, Bti suspension of ∼1×109CFU orally administered with levamisole (subcutaneously, 150mg); Group 3, only levamisole (subcutaneously, 150mg), and Group 4 untreated. Then 24 and 48h after treatment, larvae numbers were counted. We observed a reduction of 84%, 100%, and 100% after 48h of treatment, respectively, for Groups 1, 2 and 3 treatments in comparison with the untreated. The tested Bacillus species showed larvicidal activity against bovine trichostrongylides, and its association with anthelmintics. It may serve as a promising integrated alternative for control of gastrointestinal nematodes in cattle.

[,Targeted' and 'targeted selective treatments' in goats: Evaluation of several decision criteria and development of a practical decision key]. / Gezielte anthelminthische Behandlung bei Ziegen: Evaluation verschiedener Bewertungskriterien und Entwicklung eines praxisnahen Entscheidungsschlüssels.

INTRODUCTION: The aim of the study was to get an overview of control measures against gastrointestinal nematodes in goats in Switzerland. Based on the answers to a questionnaire, we assessed the readiness of owners to use targeted or targeted selective treatment, and to develop a practical decision tool for the indication of treatment of individual animals. The results show that the number of treatments per year decreased compared to previous studies. Furthermore, the survey shows that a large proportion of goat farmers (73.9%) is willing to change the present treatment strategy. A simple decision key based on the evaluation of body condition, the consistency of the faeces and the degree of the anaemia (FAMACHA©) was tested in a field survey. It could be shown that goat owners are able to carry out the simple protocol reliably on their own and correctly evaluate individuals regarding their need of treatment.

INTRODUCTION: Le but du présent travail était, sur la base d'une enquête, d'obtenir une vision d'ensemble du contrôle des nématodes gastro-intestinaux chez les chèvres en Suisse, d'estimer la disposition des éleveurs pour effectuer des traitements ciblés et de développer une méthode permettant de mesurer la nécessité d'un traitement individuel des animaux. Les résultats montrent que, par rapport à d'anciennes études, le nombre annuel de traitements anthelminthiques pourrait être réduit. Un grand nombre de propriétaires de chèvres (73.9%) sont prêts à modifier leur régime actuel de vermifugation. Une clé de décision, comprenant une estimation de l'état d'embonpoint, de la consistance des selles ainsi que du degré d'anémie (FAMACHA©) a été testée en pratique. Les détenteurs étaient à même, après une formation, de remplir seuls et de façon fiable le protocole et d'estimer ainsi correctement le besoin de traitement de leurs animaux.

Prospects and challenges of CRISPR/Cas genome editing for the study and control of neglected vector-borne nematode diseases.

Neglected tropical diseases caused by parasitic nematodes inflict an immense health and socioeconomic burden throughout much of the developing world. Current estimates indicate that more than two billion people are infected with nematodes, resulting in the loss of 14 million disability-adjusted life years per annum. Although these parasites cause significant mortality, they primarily cause chronic morbidity through a wide range of severe clinical ailments. Treatment options for nematode infections are restricted to a small number of anthelmintic drugs, and the rapid expansion of anthelmintic mass drug administration raises concerns of drug resistance. Preservation of existing drugs is necessary, as well as the development of new treatment options and methods of control. We focus this review on how the democratization of CRISPR/Cas9 genome editing technology can be enlisted to improve our understanding of the biology of nematode parasites and our ability to treat the infections they cause. We will first explore how this robust method of genome manipulation can be used to newly exploit the powerful model nematode Caenorhabditis elegans for parasitology research. We will then discuss potential avenues to develop CRISPR/Cas9 editing protocols in filarial nematodes. Lastly, we will propose potential ways in which CRISPR/Cas9 can be used to engineer gene drives that target the transmission of mosquito-borne filarial nematodes.

Cerebrospinal Nematodiasis in 20 Camelids.

BACKGROUND: Information about the clinical and clinicopathologic aspects of cerebrospinal nematodiasis (CN) in camelids is limited. HYPOTHESIS: Clinical and therapeutic variables will be identified as factors predictive of survival. ANIMALS: Client-owned camelids suspected of having CN admitted to Purdue University between 1995 and 2015. METHODS: A retrospective study was performed. A diagnosis of CN was based on cerebrospinal fluid (CSF) eosinophilic pleocytosis or postmortem findings. RESULTS: Eleven alpacas and 9 llamas met the inclusion criteria. Seventy-five percent of the camelids were male (27% castrated and 73% intact). Common clinical abnormalities included proprioceptive deficits (100% of animals), recumbency (55%), tachypnea (55%), and ataxia (40%). Among the 85% of treated animals, 100% received PO fenbendazole, and 88% received a nonsteroidal anti-inflammatory drug. The survival rate to discharge was 45%. Plasma fibrinogen concentration, creatine kinase activity, and serum creatinine concentration were significantly higher in nonsurvivors. Blood eosinophil count, platelet count, and total CO2 were significantly lower in nonsurvivors. Factors associated with survival were species, sex, absence of treatment with corticosteroids, and clinical improvement. There was no association between recumbency at admission and survival. A plasma fibrinogen concentration above >266 mg/dL was an excellent diagnostic test to predict survival in the presence of neurological signs or CSF eosinophilia. CONCLUSIONS: Although prognosis for CN in camelids is guarded, presence of recumbency at admission is not predictive of nonsurvival. Male camelids and llamas appear more likely to die from CN. Corticosteroid treatment is contraindicated in animals diagnosed with CN.

Anthelmintic effects of forage chicory (Cichorium intybus) against gastrointestinal nematode parasites in experimentally infected cattle.

Two experiments studied the effects of dietary chicory against gastrointestinal nematodes in cattle. In Experiment (Exp.) 1, stabled calves were fed chicory silage (CHI1; n = 9) or ryegrass/clover hay (CTL1; n = 6) with balanced protein/energy intakes between groups. After 16 days, all calves received 10 000 Ostertagia ostertagi and 66 000 Cooperia oncophora third-stage larvae (L3) [day (D) 0 post-infection (p.i.)]. In Exp. 2, calves were assigned to pure chicory (CHI2; n=10) or ryegrass/clover (CTL2; n = 10) pastures. After 7 days, animals received 20 000 O. ostertagi L3/calf (D0 p.i.) and were moved regularly preventing pasture-borne infections. Due to poor regrowth of the chicory pasture, CHI2 was supplemented with chicory silage. At D40 p.i. (Exp. 1) and D35 p.i. (Exp. 2) calves were slaughtered for worm recovery. In Exp.1, fecal egg counts (FEC) were similar between groups. However, O. ostertagi counts were significantly reduced in CHI1 by 60% (geometric mean; P < 0·01), whereas C. oncophora burdens were unaffected (P = 0·12). In Exp. 2, FEC were markedly lowered in CHI2 from D22 p.i onwards (P < 0·01). Ostertagia ostertagi adult burdens were significantly reduced in CHI2 by 66% (P < 0·001). Sesquiterpene lactones were identified only in chicory (fresh/silage). Chicory shows promise as an anti-Ostertagia feed for cattle and further studies should investigate its on-farm use.

Understanding Heterogeneity in the Impact of National Neglected Tropical Disease Control Programmes: Evidence from School-Based Deworming in Kenya.

BACKGROUND: The implementation of soil-transmitted helminth (STH) treatment programmes occurs in varied environmental, social and economic contexts. Programme impact will be influenced by factors that affect the reduction in the prevalence and intensity of infections following treatment, as well as the subsequent rate of reinfection. To better understand the heterogeneity of programme impact and its underlying reasons, we investigated the influence of contextual factors on reduction in STH infection as part of the national school based deworming (SBD) programme in Kenya. MATERIALS AND METHODS: Data on the prevalence and intensity of infection were collected within the monitoring and evaluation component of the SBD programme at baseline and after delivery of two annual treatment rounds in 153 schools in western Kenya. Using a framework that considers STH epidemiology and transmission dynamics, capacity to deliver treatment, operational feasibility and financial capacity, data were assembled at both school and district (county) levels. Geographic heterogeneity of programme impact was assessed by descriptive and spatial analyses. Factors associated with absolute reductions of Ascaris lumbricoides and hookworm infection prevalence and intensity were identified using mixed effects linear regression modelling adjusting for baseline infection levels. PRINCIPAL FINDINGS: The reduction in prevalence and intensity of A. lumbricoides and hookworms varied significantly by county and within counties by school. Multivariable analysis of factors associated with programme impact showed that absolute A. lumbricoides reductions varied by environmental conditions and access to improved sanitation at schools or within the community. Larger reduction in prevalence and intensity of hookworms were found in schools located within areas with higher community level access to improved sanitation and within counties with higher economic and health service delivery indicator scores. CONCLUSIONS: The study identifies factors associated with the impact of school-based deworming and in particular highlights how access to water, sanitation and hygiene and environmental conditions influence the impact of deworming programmes.

Duddingtonia flagrans in the control of gastrointestinal nematodes of horses.

Horses can harbor a large amount of parasites that may cause serious clinical signs even death. The aim of this study was to evaluate the predatory activity of the fungus Duddingtonia flagrans against infective larvae (L3) of gastrointestinal nematodes of horses in fecal culture. The experimental design was completely randomized with three treated groups (G1, G2 and G3) and one control (CG), using eight animals/group. The treated animals received G1: 1.5 × 10(5); G2: 3 × 10(5) and G3: 6 × 10(5) chlamydospores of D. flagrans/kg body weight during 21 days. The fungi preparation was given at every other three-day interval. Faecal samples were collected during 30 days, on the same interval, to perform the fecal egg counts (EPG) and fecal culture for each horse. All groups demonstrated similar results for the EPG (P > 0.05) counts. D. flagrans significantly reduced (P < 0.05) the number of infective larvae after 72 h-interval between treatments. The G2 and G3 promoted higher results (P < 0.05) of L3 reduction compared to the CG. The biological control with the predacious fungi D. flagrans is still a promising free-living parasite regulator alternative to be use in livestock.

Tannin containing legumes as a model for nutraceuticals against digestive parasites in livestock.

Parasitic infections with gastrointestinal nematodes (GINs) still represent a worldwide major pathological threat associated with the outdoor production of various livestock species. Because of the widespread resistance to synthetic chemical anthelmintics, there is a strong impetus to explore novel approaches for a more integrated management of these infections. The use of nutraceuticals in the control of GINs is one of the alternatives which has been widely studied for 20 years. The objectives of this review are: (i) to define and illustrate the concept of 'nutraceutical' in the context of veterinary parasitology based on data obtained on the most studied models to control GINs in small ruminants, the tannin-containing legumes (Fabaceae); (ii) to illustrate how the 'nutraceutical concept' could be expanded to other plants, other livestock production systems and other GI parasitic diseases, and (iii) to explain how this concept is opening up new research fields for better understanding the interactions between the host, the digestive parasites and the environment.