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Michael Hess - One of the best experts on this subject based on the ideXlab platform.
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Histomonas meleagridis Molecular Traits—From Past to Future
Eukaryome Impact on Human Intestine Homeostasis and Mucosal Immunology, 2020Co-Authors: Ivana Bilic, Michael HessAbstract:The protozoan parasite Histomonas meleagridis is the causative agent of histomonosis, a poultry disease whose significance is underlined by the absence of any licenced prophylaxis or treatment. Considering the parasite-bacteria interplay, histomonosis represents an intriguing interaction in medicine. The present review targets the molecular research on H. meleagridis, covering the period after re-emergence of histomonosis at the beginning of the twenty-first century until today, from early phylogenetic studies to recent investigations applying omics techniques.
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interplay between Histomonas meleagridis and bacteria mutualistic or predator prey
Trends in Parasitology, 2020Co-Authors: Ivana Bilic, Michael HessAbstract:Histomonas meleagridis is an extracellular protozoan parasite and the aetiological agent of histomonosis, an important poultry disease whose impact is greatly accentuated by inaccessibility of any treatment. A special feature of the parasite is its intricate interplay with bacteria in vitro and in vivo, the focus of this article.
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Interplay between Histomonas meleagridis and Bacteria: Mutualistic or Predator–Prey?
Trends in parasitology, 2020Co-Authors: Ivana Bilic, Michael HessAbstract:Histomonas meleagridis is an extracellular protozoan parasite and the aetiological agent of histomonosis, an important poultry disease whose impact is greatly accentuated by inaccessibility of any treatment. A special feature of the parasite is its intricate interplay with bacteria in vitro and in vivo, the focus of this article.
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Histomonas meleagridis molecular traits from past to future
2020Co-Authors: Ivana Bilic, Michael HessAbstract:The protozoan parasite Histomonas meleagridis is the causative agent of histomonosis, a poultry disease whose significance is underlined by the absence of any licenced prophylaxis or treatment. Considering the parasite-bacteria interplay, histomonosis represents an intriguing interaction in medicine. The present review targets the molecular research on H. meleagridis, covering the period after re-emergence of histomonosis at the beginning of the twenty-first century until today, from early phylogenetic studies to recent investigations applying omics techniques.
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Cholesterol supplementation improves growth rates of Histomonas meleagridis in vitro
Experimental parasitology, 2018Co-Authors: Janine Gruber, Alena Pletzer, Michael HessAbstract:Abstract Research on the energy metabolism of various protozoan parasites showed the essentiality and benefits of cholesterol in the cultivation of these organisms. However, not much is known about the energy metabolism of Histomonas meleagridis, although such information is of high importance to improve cultivation of the parasite for advancements in diagnostics, research and vaccine development. By supplementing a serum enriched cultivation medium with cholesterol, numbers of parasites could be doubled in comparison to unsupplemented negative controls. This effect was demonstrated for two different strains of the parasite, at different levels of in vitro-passages and for histomonads under xenic or monoxenic settings. Supplementing medium free of serum with cholesterol, resulted in significant growth of the parasite over 72 h. However, there were differences in growth behaviour in serum free medium between the different histomonad cultures and continuous passaging of the cultures without serum was not possible. Monitoring the bacterial growth of two different co-cultivated E. coli strains in monoxenic histomonad cultures during these experiments showed that there was no significant impact of cholesterol on the bacteria. Therefore, a direct effect of cholesterol on the parasite itself could be demonstrated. The results of these experiments supply new insights into the metabolism of H. meleagridis and it can be concluded that cholesterol is an important component to enhance parasite growth in vitro.
Hafez M Hafez - One of the best experts on this subject based on the ideXlab platform.
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Experimental infections with the protozoan parasite Histomonas meleagridis: a review
Parasitology Research, 2013Co-Authors: Rudiger Hauck, Hafez M HafezAbstract:In recent years, a number of studies about Histomonas meleagridis , and more specifically about experiments in vivo involving H . meleagridis to investigate the pathogenicity and efficacy of drugs or vaccines, have been published. Together with older publications, a considerable amount of information about experimental infections with H . meleagridis exist, which is helpful for planning future animal studies and can reduce the number of birds used in such studies toward better animal welfare. One hundred sixty-seven publications describing experimental infections with H . meleagridis were published in scientific journals between 1920 and 2012. One hundred forty-two of these publications describe infections of turkeys ( Meleagris gallopavo ) and 52 infections of chickens ( Gallus gallus ). In 18 studies, experiments involving other species were done. The most popular routes of infection were the intracloacal application of histomonal trophozoites from culture material, from lesions or from feces of infected birds, or using larvae of the cecal worm Heterakis gallinarum (83 studies) and the oral application of eggs or other stages of the cecal worm containing histomonal stages (83 studies). During the last 10 years, intracloacal application of trophozoites has become the most popular way to experimentally infect birds with H . meleagridis due to its high reproducibility and reliability. In most studies, infection doses of several 10,000 or 100,000 histomonal trophozoites were used for infection, and the resulting mortality in turkeys was more than 70 %. First mortality can occur as early as 6 days p.i.; peak mortality usually is 13–15 days p.i. Lower infection doses may delay mortality about 2 days. In chickens infected by the intracloacal route, mortality and clinical signs are rare, but infection rates are similar. Cecal lesions can be observed from 3 to 4 days p.i., lesions up to 3 weeks p.i.; liver lesions may be lacking completely or be present only in a small number of birds. In most studies infecting birds with Heterakis eggs containing histomonal stages, several 100 to 1,000 Heterakis eggs were used. However, lower doses might be sufficient, as infection with as few as 58 eggs per bird caused a mortality up to 90 % in turkeys. Clinical symptoms start 9 days p.i., and first mortality occurs after 12 days, while most of the infected birds die between 19 and 21 days p.i. The infectivity of Heterakis eggs containing histomonal stages for chickens is similar as for turkeys, but mortality and clinical signs are rare. Further infection was done by oral application of histomonal trophozoites either grown in culture or using lesions or feces of infected birds (26 studies). These yielded very mixed results, with infection rates between 0 and more than 80 % in turkeys and chickens. After successful oral infection of turkeys, mortality occurs at roughly the same time as after intracloacal infection. Further 18 studies employed seeder birds to infect in-contact birds. Other means of infection were exposure to contaminated soil or litter (22 studies), feeding contaminated earthworms (7 studies), intracecal inoculation (4 studies), or parenteral injection (4 studies). Main methods to assess the course of the infection were mortality, observation of clinical signs and pathological lesions, monitoring of the weight of the infected birds, and detection of the parasite by various methods.
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detection of dna of Histomonas meleagridis and tetratrichomonas gallinarum in german poultry flocks between 2004 and 2008
Avian Diseases, 2010Co-Authors: Rudiger Hauck, Stefanie Balczulat, Hafez M HafezAbstract:Between 2004 and 2008, 338 samples from 156 German turkey, chicken, and peacock flocks with suspected histomonosis (histomoniasis) were sent to the Institute for Poultry Diseases of the Free University Berlin. Most samples were from ceca or livers; the other samples were organ pools or were taken from other organs or the environment. In 108 samples from 65 flocks, histomonal DNA was detected by polymerase chain reaction (PCR). Tetratrichomonas gallinarum DNA was found in 5.3% of investigated samples from flocks infected with Histomonas meleagridis and in 27.4% of investigated samples from flocks that were not infected with H. meleagridis. For subtyping of the strains, the C-profiling method, a method used to analyze the internal transcribed spacer-1 (ITS-1) of the rRNA gene, was modified to be more specific for H. meleagridis. Results showed the presence of more than the three subtypes described so far. There was no clear correlation between the subtype and the host. By C-profiling the clonal cultures, heterogeneous ITS-1 sequences were shown to probably result from intragenomic differences between rRNA genes.
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pilot study on the efficacy of paromomycin as a histomonostatic feed additive in turkey poults experimentally infected with Histomonas meleagridis
Archives of Animal Nutrition, 2010Co-Authors: Hafez M Hafez, Rudiger Hauck, Wael Gad, Koen De Gussem, Abdulrahman LotfiAbstract:Paromomycin is an aminoglycoside antibiotic with activity against protozoa. Currently, paromomycin is registered for food producing animal species. In a pilot study we evaluated the efficacy of different doses of paromomycin in the feed against Histomonas meleagridis in experimentally challenged turkey poults. Groups consisting of 30 birds each were given feed with 100, 200 and 400 ppm paromomycin, respectively, starting on day 1 through to day 42. One group of 30 birds was left untreated. On day 21 all birds were infected intracloacally with H. meleagridis. Additionally, 10 birds were kept as a non-infected and non-treated control group. Before the challenge there was no significant difference between untreated and treated groups with regards to feed consumption and feed conversion rate. After the challenge, mortality was 80% in the infected non-treated birds. In the treated groups the mortality rate was 73.3%, 43.3% and 20%, respectively. No histomonal DNA was found in caeca and livers of the surviving ...
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Research Note— Factors Influencing the Activity of Tiamulin Against Histomonas meleagridis In Vitro
2010Co-Authors: R. Hauck, Abdulrahman Lotfi, Hafez M HafezAbstract:SUMMARY. In this study, we investigated the activity of tiamulin fumerate against three strains of Histomonas meleagridis in vitro under different conditions. Tiamulin reduced histomonal growth of all three strains at concentrations of 20 ppm and higher. Cultures in phosphate-buffered saline-based medium were more susceptible than cultures in traditional Dwyers medium. When the cultures were inoculated with higher numbers of histomonads, the activity of tiamulin was reduced. Bacteria present in the cultures were resistant against tiamulin.
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Factors Influencing the Activity of Tiamulin Against Histomonas meleagridis In Vitro
Avian diseases, 2010Co-Authors: R. Hauck, Abdulrahman Lotfi, Hafez M HafezAbstract:In this study, we investigated the activity of tiamulin fumerate against three strains of Histomonas meleagridis in vitro under different conditions. Tiamulin reduced histomonal growth of all three strains at concentrations of 20 ppm and higher. Cultures in phosphate-buffered saline-based medium were more susceptible than cultures in traditional Dwyers medium. When the cultures were inoculated with higher numbers of histomonads, the activity of tiamulin was reduced. Bacteria present in the cultures were resistant against tiamulin.
Matthias Gauly - One of the best experts on this subject based on the ideXlab platform.
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non starch polysaccharides alter interactions between heterakis gallinarum and Histomonas meleagridis
Veterinary Parasitology, 2011Co-Authors: Gurbuz Das, Hansjorg Abel, Julia Humburg, Anna Schwarz, Silke Rautenschlein, Gerhard Breves, Matthias GaulyAbstract:Nutrition of the host animal may not only influence interactions between the host and its parasites, but also relations between different parasites species residing on the same host. We investigated effects of insoluble and soluble non-starch polysaccharides (NSP) on establishment and development of Heterakis gallinarum in chicken being treated or left untreated against Histomonas meleagridis. Six groups of one-day-old birds were allocated to three diets, two on each diet. The birds were fed ad libitum either a basal diet (CON), or CON+insoluble NSP (I-NSP) or CON+soluble NSP (S-NSP) until an age of 11wk. At an age of 19d, one of each diet groups was prophylactically treated for 9d with dimetridazole (0.05%, w/v) via drinking water against Histomonas. The remaining three groups were left un-treated. Two days after starting dimetridazole treatment (at 3wk), each of the 6 groups was divided into two sub-groups. One dimetridazole treated and one dimetridazole un-treated groups of birds on each diet (6 groups) were infected with 200 embryonated eggs of H. gallinarum that were previously harvested from Histomonas-carrying H. gallinarum infected chickens. The remaining 6 groups of uninfected birds, either treated or left un-treated against H. meleagridis, served as controls. Worm burdens of infected birds were determined 8wk p.i. Treatment against H. meleagridis significantly increased incidence of H. gallinarum infection and average worm length in all infected groups independent of the diet consumed (p 0.05). Both NSP supplemented diets resulted in lower (p<0.05) BW when compared with the CON diet, S-NSP being inferior to I-NSP (p<0.05). It is concluded that H. meleagridis harms the definitive host as well as H. gallinarum. Both insoluble and soluble NSP supplemented diets favor H. gallinarum infection while S-NSP additionally intensifies Histomonas infection, which then impairs establishment and development of H. gallinarum.
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Non-starch polysaccharides alter interactions between Heterakis gallinarum and Histomonas meleagridis.
Veterinary parasitology, 2010Co-Authors: Gurbuz Das, Hansjorg Abel, Julia Humburg, Anna Schwarz, Silke Rautenschlein, Gerhard Breves, Matthias GaulyAbstract:Nutrition of the host animal may not only influence interactions between the host and its parasites, but also relations between different parasites species residing on the same host. We investigated effects of insoluble and soluble non-starch polysaccharides (NSP) on establishment and development of Heterakis gallinarum in chicken being treated or left untreated against Histomonas meleagridis. Six groups of one-day-old birds were allocated to three diets, two on each diet. The birds were fed ad libitum either a basal diet (CON), or CON+insoluble NSP (I-NSP) or CON+soluble NSP (S-NSP) until an age of 11wk. At an age of 19d, one of each diet groups was prophylactically treated for 9d with dimetridazole (0.05%, w/v) via drinking water against Histomonas. The remaining three groups were left un-treated. Two days after starting dimetridazole treatment (at 3wk), each of the 6 groups was divided into two sub-groups. One dimetridazole treated and one dimetridazole un-treated groups of birds on each diet (6 groups) were infected with 200 embryonated eggs of H. gallinarum that were previously harvested from Histomonas-carrying H. gallinarum infected chickens. The remaining 6 groups of uninfected birds, either treated or left un-treated against H. meleagridis, served as controls. Worm burdens of infected birds were determined 8wk p.i. Treatment against H. meleagridis significantly increased incidence of H. gallinarum infection and average worm length in all infected groups independent of the diet consumed (p
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Non-starch polysaccharides alter interactions between Heterakis gallinarum and Histomonas meleagridis
Veterinary Parasitology, 2010Co-Authors: Gurbuz Das, Hansjorg Abel, Julia Humburg, Anna Schwarz, Silke Rautenschlein, Gerhard Breves, Matthias GaulyAbstract:Nutrition of the host animal may not only influence interactions between the host and its parasites, but also relations between different parasites species residing on the same host. We investigated effects of insoluble and soluble non-starch polysaccharides (NSP) on establishment and development of Heterakis gallinarum in chicken being treated or left untreated against Histomonas meleagridis. Six groups of one-day-old birds were allocated to three diets, two on each diet. The birds were fed ad libitum either a basal diet (CON), or CON+insoluble NSP (I-NSP) or CON+soluble NSP (S-NSP) until an age of 11wk. At an age of 19d, one of each diet groups was prophylactically treated for 9d with dimetridazole (0.05%, w/v) via drinking water against Histomonas. The remaining three groups were left un-treated. Two days after starting dimetridazole treatment (at 3wk), each of the 6 groups was divided into two sub-groups. One dimetridazole treated and one dimetridazole un-treated groups of birds on each diet (6 groups) were infected with 200 embryonated eggs of H. gallinarum that were previously harvested from Histomonas-carrying H. gallinarum infected chickens. The remaining 6 groups of uninfected birds, either treated or left un-treated against H. meleagridis, served as controls. Worm burdens of infected birds were determined 8wk p.i. Treatment against H. meleagridis significantly increased incidence of H. gallinarum infection and average worm length in all infected groups independent of the diet consumed (p 0.05). Both NSP supplemented diets resulted in lower (p
Elvira Grabensteiner - One of the best experts on this subject based on the ideXlab platform.
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Antiprotozoal activities determined in vitro and in vivo of certain plant extracts against Histomonas meleagridis, Tetratrichomonas gallinarum and Blastocystis sp.
Parasitology Research, 2008Co-Authors: Elvira Grabensteiner, Dieter Liebhart, Najma Arshad, Michael HessAbstract:A total of 43 plant substances provided as raw material and different kinds of extracts (aqueous, ethanol, and heptane) from 18 different organic wastes obtained from the food/feed industry were investigated for their in vitro activities against clonal cultures of Histomonas meleagridis , Tetratrichomonas gallinarum , and Blastocystis sp. Ethanolic extracts of thyme, saw palmetto, grape seed, and pumpkin fruit proved to be most efficacious. Thus, these extracts were further tested in vivo in turkeys experimentally infected with H. meleagridis by administrating the substances to the birds through the drinking water. Even though a delayed mortality was noticed in some birds medicated with the extracts of thyme, grape seed, and pumpkin fruit, all birds died or had to be euthanized the latest within 5 weeks post infection—with the exception of one bird which was probably never infected with histomonads—due to a severe typhlohepatitis indicative for histomonosis. In addition, none of the substances were able to prevent the spreading of H. meleagridis from infected to in-contact birds. Thus, these studies clearly demonstrate that in vitro studies are of limited value to assess the efficacy of plant substances against histomonosis.
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Cloned Histomonas meleagridis passaged in vitro resulted in reduced pathogenicity and is capable of protecting turkeys from histomonosis.
Vaccine, 2008Co-Authors: Michael Hess, Dieter Liebhart, Elvira Grabensteiner, A SinghAbstract:Histomonas meleagridis is a flagellated protozoan parasite and the aetiological agent of histomonosis (histomoniasis or blackhead disease), a severe disease in poultry with very limited options for treatment. In the present investigation an inactivated vaccine, based on destroyed parasites and administered by intramuscular injection, failed to induce an efficient protection against a severe challenge. By cloacal infection of 14-day-old turkeys with cloned protozoa passaged in vitro for 95, 215 or 295 times, respectively, severe attenuation could be demonstrated as none of the infected birds died. Following infection with one of the higher passages, the birds resisted the challenge with virulent parasites. Using this approach no mortality due to histomonosis could be recorded in all of the 42 birds subjected to vaccination, either through direct infection or kept as in-contact birds, whereas all of the control animals died. Pathological lesions in the liver and caeca were only noticed in a few birds. The absence of parasitic DNA in the liver of vaccinated birds confirmed the effect of vaccination. For the first time vaccination of turkeys is reported to induce a solid protection against a severe challenge, both based on a clonal culture of Histomonas meleagridis.
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A virulent mono-eukaryotic culture of Histomonas meleagridis is capable of inducing fatal histomonosis in different aged turkeys of both sexes, regardless of the infective dose.
Avian diseases, 2008Co-Authors: Dieter Liebhart, Elvira Grabensteiner, Michael HessAbstract:Abstract Histomonosis (syn. histomoniasis) is a parasitic disease which affects predominately turkeys but also other avian species. Concurrent with the ban of therapeutic and prophylactic substances, the disease, caused by the flagellated protozoon Histomonas meleagridis, is more frequently reported. Due to somewhat diverse results reported in the past, a well-characterized culture was used in the present study to investigate the possible influence of certain parameters on the outcome of the disease. For this study, turkeys were infected with different doses of the mono-eukaryotic culture Histomonas meleagridis/Turkey/Austria/2922-C6/04 using birds of both sexes at various ages. All study groups consisted of 14 birds, of which 10 birds were directly infected via the cloacal route and four birds were kept as in-contact birds. This scheme was used to investigate the pathogenicity of the cloned isolate in 1-day-old and 14-day-old turkeys. In 8-week-old turkeys, only eight birds out of 12 were infected. When ...
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Differences in the in vitro susceptibility of mono-eukaryotic cultures of Histomonas meleagridis, Tetratrichomonas gallinarum and Blastocystis sp. to natural organic compounds
Parasitology Research, 2007Co-Authors: Elvira Grabensteiner, Najma Arshad, Michael HessAbstract:Currently, all pharmaceuticals for the treatment or prophylaxis of blackhead disease (histomonosis) caused by the flagellate Histomonas meleagridis are banned from the market. Consequently, great interest exists on the finding of alternative drugs for the abatement of histomonosis. In this study, carvacrol, Cassia oil, an essential oil (EO) mixture containing thyme and rosemary EO and a Quillaja saponaria saponin were examined using in vitro assays for antiprotozoal and antibacterial activity testing established against cloned xenic cultures of different isolates of Histomonas meleagridis , Tetratrichomonas gallinarum and Blastocystis sp. Whereas similar minimal lethal concentrations (MLCs) of five Histomonas isolates were obtained for both carvacrol and the EO mixture as well as for the saponin, significantly different MLCs were observed for them with Cassia oil , ranging from 0.25 up to 0.50 μl/ml. Testing the Blastocystis isolates, different MLCs were obtained for all substances, whereas the Tetratrichomonas gallinarum isolates showed identical susceptibilities. The effects are independent of the bacteria, underlining the need of well-defined protozoan cultures for these investigations.
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Differences in the in vitro susceptibility of mono-eukaryotic cultures of Histomonas meleagridis, Tetratrichomonas gallinarum and Blastocystis sp. to natural organic compounds
Parasitology Research, 2007Co-Authors: Elvira Grabensteiner, Najma Arshad, Michael HessAbstract:Currently, all pharmaceuticals for the treatment or prophylaxis of blackhead disease (histomonosis) caused by the flagellate Histomonas meleagridis are banned from the market. Consequently, great interest exists on the finding of alternative drugs for the abatement of histomonosis. In this study, carvacrol, Cassia oil, an essential oil (EO) mixture containing thyme and rosemary EO and a Quillaja saponaria saponin were examined using in vitro assays for antiprotozoal and antibacterial activity testing established against cloned xenic cultures of different isolates of Histomonas meleagridis , Tetratrichomonas gallinarum and Blastocystis sp. Whereas similar minimal lethal concentrations (MLCs) of five Histomonas isolates were obtained for both carvacrol and the EO mixture as well as for the saponin, significantly different MLCs were observed for them with Cassia oil , ranging from 0.25 up to 0.50 μl/ml. Testing the Blastocystis isolates, different MLCs were obtained for all substances, whereas the Tetratrichomonas gallinarum isolates showed identical susceptibilities. The effects are independent of the bacteria, underlining the need of well-defined protozoan cultures for these investigations.
Wil J. M. Landman - One of the best experts on this subject based on the ideXlab platform.
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Assessment of the antihistomonal effect of paromomycin and tiamulin.
Tijdschrift voor diergeneeskunde, 2011Co-Authors: H.m.j.f. Van Der Heijden, K. De Gussem, Wil J. M. LandmanAbstract:Histomonosis, a parasitic disease of galliformes and sporadically of other birds caused by Histomonas meleagridis, can result in very high mortality, especially in turkeys. The ban on the last antihistomonal drug prompted an urgent search for alternative prevention and treatment strategies. As both paromomycin and tiamulin have been reported to have antihistomonal activity, these antibiotics were investigated in vitro by adding two-fold serial dilutions ranging from 12.5 to 400 microg/mL to cultures of H. meleagridis. Controls (no antibiotics, or 12.5 microg or 400 microg/mL dimetridazole) were included. Parasites were counted after 3, 20, 28, 44, 51, and 71 hours of incubation. Tiamulin did not have a clear antihistomonal effect, but paromomycin had an inhibitory effect at all concentrations tested. The latter antibiotic was subsequently examined in an in vivo study. Five groups of 20 1-day-old poults, matched by weight and sex, were either not treated (infected and uninfected control groups) or treated with paromomycin (100, 200, or 400 ppm) added to their feed. After 2 weeks all groups, except for the uninfected control group, were intracloacally inoculated with 200,000 histomonads per bird. A clear dose-response effect was found for paromomycin. In the 100-ppm paromomycin group, mortality was similar to that in the untreated control group, whereas about half of the birds died in the 200-ppm paromomycin group; almost complete protection against histomonosis was seen in the 400-ppm paromomycin group. This study shows that paromomycin supplied in feed at 400 ppm is a potentially preventive strategy against H. meleagridis.
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In vitro effect of herbal products against Histomonas meleagridis.
Veterinary parasitology, 2008Co-Authors: Harold M. J. F. Van Der Heijden, Wil J. M. LandmanAbstract:The ban on chemotherapeutics against Histomonas meleagridis in the European Union has left turkey producers without an effective treatment against histomonosis. It has encouraged the development of alternative control methods amongst which are a number of herbal products. In the present study the in vitro effect of four herbal products against H. meleagridis was examined. After suspension of the herbal products in Dwyer's culture medium used for subculturing of a viable culture, parasite growth was monitored by frequently counting the histomonads until 72h of incubation. The solid products Aromabiotictrade mark, Enteroguardtrade mark, and Protophyt SPtrade mark as well as the positive control products dimetridazole and Histostat-50trade mark, were tested in twofold serial dilutions ranging in concentration from 400 to 12.5mug/mL, while the liquid product Protophyt Btrade mark was tested in concentrations ranging from 0.24% to 0.008% (v/v). The herbal products Enteroguardtrade mark and Protophyt Btrade mark as well as dimetridazole and Histostat-50trade mark, two chemotherapeutics with known antihistomonal activity, inhibited the growth of H. meleagridis, while no antihistomonal effect was found for Aromabiotictrade mark and Protophyt SPtrade mark.
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In vitro effect of herbal products against Histomonas meleagridis.
Veterinary Parasitology, 2008Co-Authors: Harold M. J. F. Van Der Heijden, Wil J. M. LandmanAbstract:The ban on chemotherapeutics against Histomonas meleagridis in the European Union has left turkey producers without an effective treatment against histomonosis. It has encouraged the development of alternative control methods amongst which are a number of herbal products. In the present study the in vitro effect of four herbal products against H. meleagridis was examined. After suspension of the herbal products in Dwyer's culture medium used for subculturing of a viable culture, parasite growth was monitored by frequently counting the histomonads until 72 h of incubation. The solid products Aromabiotic™, Enteroguard™, and Protophyt SP™ as well as the positive control products dimetridazole and Histostat-50™, were tested in twofold serial dilutions ranging in concentration from 400 to 12.5 μg/mL, while the liquid product Protophyt B™ was tested in concentrations ranging from 0.24% to 0.008% (v/v). The herbal products Enteroguard™ and Protophyt B™ as well as dimetridazole and Histostat-50™, two chemotherapeutics with known antihistomonal activity, inhibited the growth of H. meleagridis, while no antihistomonal effect was found for Aromabiotic™ and Protophyt SP™.
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In vivo effect of herbal products against Histomonas meleagridis in turkeys
Avian pathology : journal of the W.V.P.A, 2008Co-Authors: Harold M. J. F. Van Der Heijden, Wil J. M. LandmanAbstract:Histomoniasis is a serious disease in poultry. All chemotherapeutics with known efficacy against its causative agent, Histomonas meleagridis, have been banned from use as prophylactic or therapeutic use in production animals. In a search for possible alternatives, the in vivo effects of the herbal products Enteroguard™ and Protophyt™ were examined. Two-week-old turkeys allocated into 13 groups of 18 birds were either sham inoculated (negative control group) or were inoculated with 100, 3162 or 200 000 histomonads per bird. Control groups (no feed additives, dimetridazole, or Histostat-50™) were included in the study. No morbidity or mortality was observed in the negative control group or in the groups inoculated with 100 histomonads per bird. Mortality was 100% in the groups inoculated with 200 000 histomonads per bird and either untreated (positive control group) or receiving Protophyt SP™, Protophyt™ SP and Protophyt™ B, Enteroguard™, or Histostat-50™. Mortality was 17% in the dimetridazole-treated grou...
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In vivo effect of herbal products against Histomonas meleagridis in turkeys
Avian Pathology, 2008Co-Authors: Harold M. J. F. Van Der Heijden, Wil J. M. LandmanAbstract:Histomoniasis is a serious disease in poultry. All chemotherapeutics with known efficacy against its causative agent, Histomonas meleagridis, have been banned from use as prophylactic or therapeutic use in production animals. In search for possible alternatives, the in vivo effects of the herbal products Enteroguard™ and Protophyt™ were examined. Two week-old turkeys allocated in 13 groups of 18 birds were either sham inoculated (negative control group) or with 100 or 3,162 or 200,000 histomonads per bird. Control groups (no feed additives, dimetridazole, or Histostat-50™) were included in the study. No morbidity or mortality was observed in the negative control group or in the groups inoculated with 100 histomonads per bird. Mortality was 100% in the groups inoculated with 200,000 histomonads per bird and either untreated (positive control group), or receiving Protophyt SP™, Protophyt™ SP and Protophyt™ B, Enteroguard™, or Histostat-50™. Mortality was 17% in the dimetridazole treated group. In the groups inoculated with 3,162 histomonads per bird, mortality was 100% for the positive control group and the group receiving Enteroguard™, and 94% in the group receiving Protophyt™ SP. In this study Enteroguard™ or Protophyt™ were not found to be effective against histomoniasis.