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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.
Ivana Bilic - 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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Unravelling the differences: comparative proteomic analysis of a clonal virulent and an attenuated Histomonas meleagridis strain.
International journal for parasitology, 2017Co-Authors: Andreas Monoyios, Michael Hess, Martina Patzl, Sarah Schlosser, Ivana BilicAbstract:Abstract The current study focused on Histomonas meleagridis, a unicellular protozoan, responsible for histomonosis in poultry. Recently, the occurrence of the disease increased due to the ban of effective chemotherapeutic drugs. Basic questions regarding the molecular biology, virulence mechanisms or even life cycle of the flagellate are still puzzling. In order to address some of these issues, we conducted a comparative proteomic analysis of a virulent and an attenuated H. meleagridis strain traced back to a single cell and propagated in vitro as monoxenic mono-eukaryotic cultures. Using two-dimensional electrophoresis (2-DE) for proteome visualization with computational 2-DE gel image and statistical analysis, upregulated proteins in either of the two H. meleagridis strains were detected. Statistical analysis fulfilling two criteria (≥threefold upregulation and P
L R Mcdougald - One of the best experts on this subject based on the ideXlab platform.
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Direct Lateral Transmission of Histomonas meleagridis
2016Co-Authors: L R McdougaldAbstract:SUMMARY. The lateral transmission of Histomonas meleagridis in turkeys was studied in floor pens without the presence of Heterakis gallinarum. Battery-reared poults (120) were transferred at 2 wk of age to concrete-floored floor pens with fresh pine shavings litter (40/ group). One group received no exposure. In other groups, either 10% or 25% of the birds were inoculated per cloaca with cultured H. meleagridis (200,000/bird) and placed in the pens as seeder birds. Inoculated birds died at 10-18 days postinfection (PI) showing typical liver and cecal lesions of histomoniasis. Birds in the high-exposure group died of histomoniasis beginning 16 days PI and continuing to 100% mortality by day 23 PI. Birds in the low-exposure (LE) group died beginning on day 19 PI and continuing through day 31 PI. All but one LE bird alive on day 31 PI had severe liver and cecal lesions of histomoniasis at necropsy. There was no evidence of histomoniasis in unexposed birds. No cecal worms (H. gallinarum) were found at necropsy of dead birds or in unexposed birds at the end of the experiment. Even though H. gallinarum is the only known reservoir for H. meleagridis, these results suggest that lateral transmission of histomoniasis through a flock can occur readily through normal contact between uninfected birds and infected birds and their droppings in the total absence of cecal worms.
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partial sequence of the alpha tubulin gene from Histomonas meleagridis isolates from the united states
Journal of Parasitology, 2011Co-Authors: Richard W. Gerhold, L R Mcdougald, Lori A. Lollis, Robert B. BecksteadAbstract:Abstract Histomonas meleagridis, the causative agent of histomoniasis, is a protozoan parasite classified in the Dientamoebidae (order Tritrichomonadida). The α-tubulin gene of 7 H. meleagridis isolates originating from either domestic chickens or turkeys from the United States was amplified by nested PCR and sequenced. A 91.4–99.8% nucleotide identity was shared among the 7 different sequences, and phylogenetic analysis disclosed that the 7 isolates were divided into at least 3 clades. These sequences had a 91–99% nucleotide identity and a 96–100% amino acid identity compared with 3 H. meleagridis α-tubulin sequences obtained from isolates originating from turkeys in Germany. Further α-tubulin gene analysis from species in the Dientamoebidae will be useful in elucidating the evolutionary relationship of these protozoans.
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the infection of turkey poults with Histomonas meleagridis by contact with infected birds or contaminated cages
Avian Diseases, 2011Co-Authors: P L Armstrong, L R McdougaldAbstract:SUMMARY. The conditions under which infection with Histomonas meleagridis could spread from directly inoculated turkey poults to uninoculated poults without the aid of invertebrate hosts or vectors was investigated in several experiments. In three experiments in battery cages, uninoculated poults were commingled with directly infected birds on pine-shaving litter. Directly exposed birds were inoculated per cloaca with H. meleagridis by means of a plastic pipette tip attached to a 10-ml syringe or orally gavaged with fresh cecal droppings from donor turkeys 4 days postinoculation (PI). Of the cloacally inoculated controls in these experiments, 31 of 44 (70.5%) birds had severe lesions of histomoniasis at 14 days PI, whereas none of the orally gavaged birds became infected. Histomoniasis developed in 11 of 36 (30.5%) birds allowed to commingle with inoculated birds. In other treatments, poults were allowed only contact with droppings from directly inoculated birds after the infected birds were removed from ...
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Histomonas meleagridis (Parabasala, Trichomonadea, Monocercomonadidae): presence of natural agglutinins in horse serum
Parasitology Research, 2008Co-Authors: M. Brooks, A. L. Fuller, P. Armstrong, L R McdougaldAbstract:Cultured Histomonas meleagridis cells were readily agglutinated in vitro by horse serum at concentrations as low as 5%, although clumping was more rapid and prominent at 15% or higher. For observation of clumping, the cultured organisms were washed twice in Hanks balanced solution (HBSS) by centrifugation (1,000× g for 15 min) and filtered through glass wool. The test sera were added and the mixture incubated in a Petri plate or 24-well culture plates at r.t. for 15–30 min. Formation of clumps was time- and concentration-dependent. Gentle agitation hindered agglutination at low serum concentration and accelerated agglutination at higher concentrations. The agglutinating factor (AF) was detected in several batches of serum from different sources, regardless of whether sera were heat-treated to inactivate complement. Histomonads were not clumped by either fetal horse or bovine serum (5–30%). Neither chicken nor turkey serum agglutinated histomonads to the extent seen with horse serum. Immune turkey serum lysed histomonads, hindering observation of clumping. Complement inactivation of immune serum slightly reduced lysis. AF in horse serum was precipitated with 25–40% ammonium sulfate and was active when cleaned by dialysis and reconstituted in HBSS. Clumping by serum facilitated the cleaning of histomonads for other studies where pure suspensions were needed.
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The efficacy of some drugs with known antiprotozoal activity against Histomonas meleagridis in chickens.
Veterinary Parasitology, 2004Co-Authors: L R McdougaldAbstract:Nine drugs with known or suspected antiprotozoal activity were tested in vitro, and in vivo for activity against Histomonas meleagridis. The nitroimidazoles dimetridazole, metronidazole, ornidazole, and tinidazole suppressed growth of H. meleagridis in vitro at 10 microg/ml or higher. Paromomycin sulfate, and carbadox were weakly effective at high levels. Quinolinol, mebendazole, diloxanide furoate, and albendazole had no demonstrable efficacy in vitro. Drugs showing some activity in vitro were tested in young chickens inoculated intracloacally with 2 x 10(5) H. meleagridis/bird. Dimetridazole, metronidazole, ornidazole, and tinidazole were highly effective at 200 ppm in feed. Paromomycin sulfate, and carbadox were ineffective in vivo, with no improvement in liver or cecal lesion scores compared to that of infected controls. Thus, the only new entities with efficacy against blackhead disease in vivo were nitroimidazoles, related to the positive control dimetridazole.
Elvira Grabensteiner - One of the best experts on this subject based on the ideXlab platform.
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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.
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Clonal cultures of Histomonas meleagridis, Tetratrichomonas gallinarum and a Blastocystis sp. established through micromanipulation.
Parasitology, 2006Co-Authors: Michael Hess, Elvira Grabensteiner, Thomas Kolbe, H. ProslAbstract:Clonal cultures of Histomonas meleagridis, Tetratrichomonas gallinarum and a Blastocystis sp. were established for the first time. Single microbes were successfully isolated from a mixture of micro-organisms obtained from caecal contents of turkeys, using a micromanipulation approach. The cloned parasites were propagated in vitro and maintained through continuous passages multiplying to high numbers. Identification of the protists was done by morphological investigation identifying various forms of each parasite. PCR and partial sequencing of the small subunit rRNA were used to confirm clonality and to determine the relationship of the cloned parasites with known protozoan parasites. The clonal cultures established by this technique will be useful to gain more insight into the biological repertoire of the organisms. In addition, refined infection experiments in different poultry species can now be performed to elucidate the pathological pathways of the respective protozoa.
Robert B. Beckstead - One of the best experts on this subject based on the ideXlab platform.
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Histomonas meleagridis isolates compared by virulence and gene expression.
Veterinary parasitology, 2020Co-Authors: Zehui Wei, Mathew Abraham, Elle Chadwick, Robert B. BecksteadAbstract:Abstract Pathology and putative virulence factor expression of three Histomonas meleagridis isolates differing in geographic origin, cell passage number (56 or 100), or cell populations grown from a monoculture were compared. Turkey poults inoculated with the high cell passage number isolates or monoculture isolates varied in gross lesion severity and weight gain (P
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Development of a Dry Medium for Isolation of Histomonas meleagridis in the Field
Avian diseases, 2017Co-Authors: Miguel A. Barrios, Anna Kenyon, Robert B. BecksteadAbstract:SUMMARY Blackhead disease is caused by Histomonas meleagridis, an anaerobic protozoan parasite, and results in mortality rates of up to 100% in turkeys and 30% in chickens. Outbreaks of blackhead disease are unpredictable, and the harvesting of H. meleagridis strains from the field would be a great resource for researchers to study its epidemiology. Therefore, the objective of this study was to develop a dry medium that would allow storage at ambient temperatures until needed. Fifty milliliters of horse serum was dried and then mixed with dry medium M199 with Hanks balanced salts (10.6 g), sodium bicarbonate (0.35 g), and rice powder (0.8 g). To test the ability of reconstituted medium to support growth of H. meleagridis, groups of 10 flasks containing 0.2 g of dry medium were stored for 24 hr at 25 and 60 C before testing. Other groups of flasks containing dry medium were stored at 25, 37, and 42 C for 1, 3, or 6 mo. At each test period, the flasks were reconstituted with 10 ml of water, inoculated with ...
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Blackhead disease: reduced sensitivity of Histomonas meleagridis to nitarsone in vitro and in vivo.
Avian diseases, 2014Co-Authors: Mathew Abraham, Larry R. Mcdougald, Robert B. BecksteadAbstract:SUMMARY Histomonas meleagridis, a flagellated protozoan parasite, is the causative agent of blackhead disease or histomoniasis in gallinaceous birds. Currently nitarsone (4-nitrophenylarsonic acid) is the only approved preventative drug available in the United States against blackhead disease. Initially we tested the sensitivity of three different isolates of H. meleagridis collected from outbreaks in North Carolina (strain MNC), Michigan (strain ZM), and Georgia (strain BG) to nitarsone using in vitro culture conditions. Strain ZM and strain BG at 100 and 400 ppm showed reduced growth in comparison to their respective control groups. However, there was no inhibition of growth in strain MNC treated with nitarsone at 100 ppm, while reduced growth was seen at 400 ppm. To test the resistance of strain MNC to nitarsone in vivo, turkey poults fed a nitarsone or a control diet were inoculated cloacally with H. meleagridis. The nitarsone-treated group of birds did not show any significant difference compared to ...
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A Genomic Analysis of Histomonas meleagridis Through Sequencing of a cDNA Library
The Journal of parasitology, 2012Co-Authors: Michael Edward Klodnicki, Larry R. Mcdougald, Robert B. BecksteadAbstract:Abstract: Histomonas meleagridis, a flagellated protozoan of the Order Trichomonadida, is the causative agent of blackhead disease in gallinaceous birds. Few genes have been identified in this organism; thus, little is known regarding the molecular basis for its metabolism, virulence, and antigenicity. To identify new genes, a cDNA library derived from a lab strain of H. meleagridis was sequenced and annotated. Data obtained from these experiments identified 3,425 H. meleagridis genes. Analysis of the data allowed the identification of 81 genes coding for putative hydrogenosomal proteins and was used to determine the codon usage frequency. Sequence information also identified bacteria that are cultured with H. meleagridis. Future analysis of these data should provide valuable molecular insights into H. meleagridis and provide the platform for molecular studies aimed at understanding the pathogenesis of blackhead disease.
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identification of gene expression elements in Histomonas meleagridis using splinkerette pcr a variation of ligated adaptor pcr
Journal of Parasitology, 2012Co-Authors: Elizabeth C Lynn, Robert B. BecksteadAbstract:abstract: Histomonas meleagridis is the causative agent of blackhead disease in gallinaceous birds. Limited genetic information exists for this organism, with the majority of sequence information coming from the coding regions of genes. No information is available for intergenic regions that contain DNA elements required for the regulation of gene expression. In this study, we demonstrate that splinkerette PCR, a variation of ligated adaptor PCR, can be used to identify regions of unknown sequence that lie upstream and downstream of known genomic sequences. Using this technique, we identified upstream sequences of 2 β-tubulin genes. Sequence analysis identified the 5′ coding portions of the β-tubulin genes, the intergenic regions, and 2 different open reading frames encoding for a putative serine/threonine phosphatase and a putative ras-related protein, racG. We predict that these intergenic regions contain polyadenylation and cleavage signals for the 2 open reading frames and initiator elements for the ...