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2. Differences in viability and reactivity of actinospores of three myxozoan species upon ageing
- Creator:
- Kallert, Dennis Marc and El-Matbouli, Mansour
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Myxozoa, Myxobolus cerebralis, Myxobolus pseudodispar, Henneguya nuesslini, viability, polar capsule discharge, actinospore, temperature, age, and fluorescent staining
- Language:
- English
- Description:
- Little is known about the viability of myxozoan actinospore stages after harvest from laboratory cultures of infected oligochaete worms. The viability and reactivity of actinospores of three myxozoan species was evaluated after short-term storage at 4°C and 12°C. Two methods of determining actinospore viability were compared: differential fluorescent staining and direct microscopic observation of morphological indicators of spore integrity. Spore reactivity was quantified by measuring polar filament discharge rates in a micro-assay with fish mucus substrate and mechanical stimulation by vibration. The age-dependent viability of the three species showed clear differences. Myxobolus cerebralis actinospores had the shortest effective life span whereas Henneguya nuesslini actinospores survived significantly longer. Storage at lower temperatures yielded higher viability in all species. Myxobolus pseudodispar actinospores were significantly robust up to 12°C when assessed by staining, but showed similar viability characteristics as H. nuesslini when analyzed morphologically. Evaluation of spore viability by fluorescent staining correlated with morphological assessment, although fewer viable actinospores were usually detected microscopically. Polar filament discharge activity of morphologically intact actinospores did not significantly decrease until the third day of storage compared to freshly harvested samples. The results indicate that durability and reactivity trends during storage of actinospores differ among myxozoan species.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
3. Electron microscopic study of a new microsporean Microsporidium epithelialis sp. n. infecting Tubifex sp. (Oligochaeta)
- Creator:
- Oumouna, Mustapha, El-Matbouli, Mansour, Rudolf W., and Bouix, Georges
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Microsporea, Actinosporea, ultrastructure, Oligochaeta, and Tubificidae
- Language:
- English
- Description:
- The cytology of a new microsporean parasite Microsporidium epithelialis sp. n. from the intestinal epithelial cells of the freshwater oligochaete Tubifex sp. (Tubificidae) is described. The microsporean occurred together with an actinosporean of the genus Triactinomyxon, which was found between the epithelial cells. The merogonic and sporogonie stages (mature spores included) of the microsporean parasite are monokaryotic. An individual sporophorous vesicle surrounds each spore. The fixed and stained spore has an average dimension of 1.9-2.5 x 0.9-1.2 pm. The spores are oval with a characteristic surface layer, showing ornamentation-like projections, which are in close contact to the exosporc. A short polar filament forming three to four coils traverses the polaroplast with two lamellar layers. The ultrastructure and other characteristic features of this microsporean parasite are distinct from those of the microsporean species described so far from oligochaetes.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. Extensive release of an antigen associated with the sporogonic stages of Myxobolus cerebralis (Myxozoa: Myxosporea) is detected by a heterologous antibody raised to Tetracapsuloides bryosalmonae (Myxozoa: Malacosporea)
- Creator:
- Morris, David J., El-Matbouli, Mansour, and Adams, Alexandra
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- PKX, Tetracapsula, whirling disease, and antibody
- Language:
- English
- Description:
- Monoclonal antibody B4 (mAb B4) was previously developed to the myxozoan parasite Tetracapsuloides bryosalmonae Canning, Curry, Feist, Longshaw et Okamura, 1999, the causative agent of proliferative kidney disease of salmonids. Here we describe the reaction of mAb B4 against Myxobolus cerebralis Hofer, 1903, the parasite that causes 'whirling disease' in salmonids. Tissues examined were collected from experimentally infected rainbow trout Oncorhynchus mykiss (Walbaum) and the aquatic oligochaete Tubifex tubifex (O.F. Müller), the two hosts involved in the life cycle of M. cerebralis. Paraffin sections of infected rainbow trout taken at 4 h and 3, 10, 17 and 54 days post-exposure to infective M. cerebralis actinospores were immunohistochemically stained with mAb B4. Longitudinal sections through infected T. tubifex sampled 120 days post-exposure to M. cerebralis myxospores were also examined using this method. The only phase of the M. cerebralis life cycle that expressed the mAb B4 antigen was during sporogenesis in the salmonid host. The immunohistochemical staining demonstrated that the antigen was released into the tissues surrounding the spore and sporogonic stages of the parasite. The localisation of the antigen was diffuse in the fish, suggesting that the possible effect of M. cerebralis infection is extensive through the head tissues and not limited to areas of cartilage destruction as previously thought.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public