Transmission electron microscopic studies of stages of Histomonas meleagridis from clonal cultures

Mielewczik, Michael; Mehlhorn, Heinz; Al‐Quraishy, Saleh; Grabensteiner, Elvira; Heß, Michael

doi:10.1007/s00436-008-1009-1

Cited by 22 publications

(23 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The capability of T. gallinarum to convert into pseudocysts (Friedhoff et al 1991) might be an explanation for these observations. For H. meleagridis the presence of cysts remains questionable even though cyst like stages were noticed in feces of experimentally infected chicken (Mielewczik et al 2008).…”

Section: Discussionmentioning

confidence: 99%

Antiprotozoal activities determined in vitro and in vivo of certain plant extracts against Histomonas meleagridis, Tetratrichomonas gallinarum and Blastocystis sp.

et al. 2008

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 99%

Antiprotozoal activities determined in vitro and in vivo of certain plant extracts against Histomonas meleagridis, Tetratrichomonas gallinarum and Blastocystis sp.

et al. 2008

View full text Add to dashboard Cite

show abstract

“…Formalin-fixed tissues were routinely embedded in paraffin, and sections of 4 μm thickness were stained with haematoxylin and eosin. For transmission electron microscopy, glutaraldehyde-fixed tissues were further processed, embedded and prepared using standard laboratory methods (Mielewczik et al 2008). Two Northern goshawks (Accipiter gentilis), two Gyr-Saker (Falco rusticolus × Falco cherrug) hybrid falcons, two dogs (Canis familaris, beagle), two ferrets (Mustela putorius furo), two rats (Rattus norvegicus f. domestica) and two mice (M. musculus domesticus) were experimentally fed with a regular meal size of pectoral muscle of naturally infected pigeons.…”

Section: Methodsmentioning

confidence: 99%

Sarcocystis calchasi sp. nov. of the domestic pigeon (Columba livia f. domestica) and the Northern goshawk (Accipiter gentilis): light and electron microscopical characteristics

et al. 2009

Self Cite

View full text Add to dashboard Cite

A novel highly pathogenic Sarcocystis species has been shown to cycle between the Northern goshawk (Accipiter gentilis) as definitive host and the domestic pigeon (Columba livia f. domestica) as intermediate host. However, genetically based characteristics are only available from very few bird-infecting Sarcocystis species. We therefore further characterised morphological properties of this protozoan in both hosts. Using light and electron microscopy, oocysts and sporocysts as well as schizonts and sarcocysts were characterised and compared with available morphological features of previously reported Sarcocystis species of Northern goshawks, Columbidae and genetically closely related species of other avian hosts. Sporocysts shed from day 6 on after experimental infection by the Northern goshawk were of ovoid appearance (11.9 x 7.9 microm). Ultrastructurally, schizonts of all developmental stages were found in the liver, spleen and next to or in endothelial cells of various organs of domestic pigeons 7 to 12 days after experimental infection. The cyst wall surface of slender sarcocysts (1 to 2 mm in length and 20 to 50 microm in width) was smooth and lacked protrusions. Cystozoites were lancet-shaped and measured 7.5 x 1.5 microm in Giemsa stain smears. The morphological findings, when combined with data of experimental infection and genetic studies, convergently indicate that the recently discovered Sarcocystis species represents a new species. We therefore propose to name this parasite Sarcocystis calchasi species nova.

show abstract

“…There was found an amoebic stage without a flagellum (Levine 1973;Hess et al 2006b;Munsch et al 2008) and a stage with a single flagellum (Levine 1973;Mielewczik et al 2008;Munsch et al 2008). Recent light and transmission electron micrographs showed spherical and ovoidal cells that were clearly surrounded by two cell membranes.…”

Section: Introductionmentioning

confidence: 95%

Light and transmission electron microscopic studies on the encystation of Histomonas meleagridis

et al. 2010

Self Cite

View full text Add to dashboard Cite

The study deals with the pleomorphic zooflagellate Histomonas meleagridis, which was cultivated under different stress conditions to induce a possible encystation. In the present paper, the morphological changes were analyzed by light and electron microscopy. The determination of the proliferation under different adverse conditions led to conclusions on the tenacity of the flagellate. H. meleagridis parasitizes in the intestinal tract of galliform birds and may cause enormous losses in poultry farming. For the development of new therapy approaches, clarification of the transmission pathways will be helpful. Different clonal cultures of H. meleagridis established by micromanipulation and exposed to media lacking different ingredients, inappropriate temperatures, and/or distinct reagents were investigated. Lowering of temperature was proven to have adverse effects on the survival of H. meleagridis. The flagellate could not survive in a frozen medium, and survival in a temperature of 4 degrees C lasted no longer than 23 h. An addition of sodium chloride induced an increased proliferation; pH values between 2 and 8 set limits for the survival of the parasite in different ways. H. meleagridis was able to survive under high acidic conditions for only 1 h. The major amount of cells, which could be discovered in the controls, measured 8-12 microm appeared amoebic (stage 1) and were filled with enclosures of rice starch. A rounding of most cells was noted 4 h at 4 degrees C after incubation in minimal essential medium in the absence of rice starch and fetal calf serum. A higher osmolarity of the medium, which was initiated by the addition of sodium chloride or magnesium chloride, did not induce an encystation process. After addition of hypochlorite base and cultivating at pH values between 7 and 8, spherical stages without a flagellum were formed (stage 2) measuring about 8-12 microm in diameter. Their interior consisted of a central and a peripheral region when studied by transmission electron microscopy. This aspect was due to the location of the glycogen granules. The central zone was described as totally filled with the carbohydrates, which made totally invisible the other organelles. The solidity of the amorphous layer below the cell membrane seemed to hinder the invasion of the glycogen granules. The amorphous layer below the cell membrane made it apparently possible that the cell might survive under adverse conditions-at least for a short time. This special structure might enable H. meleagridis to proceed a fast transmission and to infect many birds in a rather short time, which was shown in the past by several studies. Double-membraned cells, which were guessed to be cyst-like structures of the parasite, were also detected (stage 3). The size of these cells, however, was much smaller than that of the amoebic stages or the above-described spherical forms of H. meleagridis. Furthermore, the small cells were characterized by other granula structures. These findings might be interpreted that the small stages are possi...

show abstract

Transmission electron microscopic studies of stages of Histomonas meleagridis from clonal cultures

Cited by 22 publications

References 18 publications

Antiprotozoal activities determined in vitro and in vivo of certain plant extracts against Histomonas meleagridis, Tetratrichomonas gallinarum and Blastocystis sp.

Antiprotozoal activities determined in vitro and in vivo of certain plant extracts against Histomonas meleagridis, Tetratrichomonas gallinarum and Blastocystis sp.

Sarcocystis calchasi sp. nov. of the domestic pigeon (Columba livia f. domestica) and the Northern goshawk (Accipiter gentilis): light and electron microscopical characteristics

Light and transmission electron microscopic studies on the encystation of Histomonas meleagridis

Contact Info

Product

Resources

About