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PubMed1987

The number of species of rodent coccidia and of other protozoa.

About 447 species of coccidia have been named from the 1687 living, known species of rodents; 207 host species, 92 host genera, and 15 host families are represented; this is about 12% of the known species of rodents. About 4600 species of apicomplexan protozoa have been named. Assuming that the same proportion of the total number of apicomplexan species has been named as of the coccidian species, there must actually be about 38,333 species of apicomplexan protozoa. There are 5.4 times as many protozoan genera as of apicomplexan genera. Assuming that the number of species in each genus is the same for all the protozoa as it is for the Apicomplexa, there may actually be 206,998 species of protozoa. This may be too conservative an estimate. Based on other criteria, an estimate of over 20 million species could be made.

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PubMed1988

A new family, genus, and seven new species of Entodiniomorphida (Protozoa) from the gut of African rhinoceros.

This report deals with a group of ciliated protozoa with short ciliary bands found mainly in the cecum of black rhinoceros, Diceros bicornis (linnaeus, 1758), and white rhinoceros, Ceratotherium simum (Burchell, 1817) from southern Africa. A new genus, Rhinozeta, based on the sum total of the characteristics of seven new related species is described. The species described are R. rhinozeta n. sp., R. triciliata n. sp., R. caecalis n. sp., R. addoensis n. sp., R. cristata n. sp., R. multiplatus n. sp., and R. unilaminatus n. sp. The specific features of the new genus make it incompatible with any of the known families of the Order Entodiniomorphida containing the ciliates present in the digestive tract of herbivorous mammals. This merits the creation of a new family, the Rhinozetidae.

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PubMedDate not supplied

Redescription of flagellar arrangement in the duck intestinal flagellate, Cochlosoma anatis and description of a new species, Cochlosoma soricis n. sp. from shrews.

Cochlosoma anatis Kotlán (Zoomastigophorea, Retortamonadida, Cochlosomidae), isolated from the large intestines of domestic Rouen ducks, and Cochlosoma soricis n. sp., isolated from the small intestines of shrews, were observed by light and scanning electron microscopy. In both organisms, a single flagellum inserted on the dorsal surface at the same level as the insertion of 4 other flagella on the ventral surface. The 4 ventro-lateral flagella emerged from the left side of the anterior attachment disk below the margin and just above the lateral groove which extended the length of the organism. A 6th flagellum emerged from the margin of the attachment disk. The proximal ends of the flagella formed a bundle with the distal ends becoming unraveled like a rope. During motility, the bundle portion extended straight out from the cell and the free ends of the flagella produced a whipping motion. In C. anatis, the dorsal surface was covered with knob-like lumps and small pits and the cells had an axostyle that emerged slightly to the right of the midline in the posterior 1/3 of the body. The axostylar tip was shorter and thicker than the flagella and in most cells it also had an irregular, knobby appearance. The irregular cell surface and axostyle were absent from C. soricis. The margin of the attachment disk curved toward the center and terminated in C. anatis as a straight edge while in C. soricis it continued as a spiral. Indentations in the mucosal brush border similar to those produced by Giardia, but distinctly belonging to Cochlosoma, were interpreted as points of attachment to the host.

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PubMedDate not supplied

Microfilum lutjani N. G. N. Sp. (Protozoa Microsporida), a gill parasite of the golden African snapper Lutjanus fulgens (Valenciennes, 1830) (Teleost Lutjanidae): developmental cycle and ultrastructure.

Microfilum lutjani n. g., n. sp. (Microsporida) was found on the gill filaments of Lutjanus fulgens (Teleost) inhabiting the coasts of Senegal. This microsporidium forms xenomas distinguished by the microvilli covering the plasma membrane. At all stages of development individuals have isolated nuclei and are in direct contact with the host cytoplasm. Merogony is binary and sporogony is tetrasporoblastic. The spore (4.75 x 2.60 microns) is characterized by a manubrium inserted on a laterally offset anchoring disc and extending into a very short, noncoiled polar filament (no longer than 500 nm) in the form of a hook. This type of polar filament has not been described previously in the Microsporida.

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PubMedDate not supplied

Henneguya adherens n. sp. (Myxozoa, Myxosporea), parasite of the Amazonian fish, Acestrorhynchus falcatus.

A new species of myxosporean from the gill filaments of the freshwater teleost fish, Acestrohynchus falcatus collected in the Amazon river is described from light and transmission electron microscope observations. The mature spores (total length 32.3 [30.7-35.1] micron) and all developmental stages were found in the same sporogonic plasmodium. The ellipsoidal spore body consists of 2 unequal shell valves adhering together along the suture lines. Each valve, tapering as a caudal projection, forms a long tail (length 20.5 [18.0-21.7] micron). The tail was surrounded by a homogeneous sheath on its length. The polar capsules measuring 3.1 x 1.2 micron contain 3-4 coils of the polar filament. All surfaces of the immature and mature spores were surrounded by a closely adherent homogenous structural sheath, mainly thicker around the tails. The taxonomic affinities of this parasite to other species are discussed.

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PubMedDate not supplied

In vitro excystation of Spironucleus muris.

In vitro excystation of Spironucleus muris cysts, purified by sequential sucrose and Percoll gradients from mouse feces, was studied. Three in vitro excystation procedures, used for Giardia, were assessed to determine the most useful method. Excystation was monitored by light microscopy and subsequently characterized by transmission and scanning electron microscopy. Spironucleus muris excysted routinely at a level greater than 90% when induced in Hanks' balanced salt solution containing sodium bicarbonate at pH 2.0 and transferred to Tyrodes' salt solution as an excystation medium. Similarly, high rates of excystation were recorded after induction of S. muris cysts in 0.1 M potassium phosphate buffer (pH 7.0) with sodium bicarbonate and excystation in trypticase-yeast extract-iron medium (TYI medium) or phosphate-buffered saline. A lower rate and percentage of excystation were observed after induction of S. muris cysts in an aqueous hydrochloric acid solution (pH 2.0) followed by excystation in TYI medium. All excystation methods produced extremely active S. muris trophozoites with normal morphology. Nonexcysting S. muris cysts have a wall composed of an outer fibrous and an inner membranous portion. Following induction, numerous vesicles appeared in the peritrophic space. Excystation began by the cyst wall opening at one pole, and the anterior part of the trophozoite protruding from the cyst wall. The trophozoite emerged progressively from the cyst wall and the empty cyst wall appeared to collapse. Excysted trophozoites exhibited normal morphological features of S. muris trophozoites isolated from the mouse intestine.

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PubMedDate not supplied

Spironucleus vortens (Diplomonadida) in the Ide, Leuciscus idus (L.) (Cyprinidae): a warm water hexamitid flagellate found in northern Europe.

The hexamitid flagellate Spironucleus vortens, previously reported from Pterophyllum scalare from Florida, was found in the intestine of Leuciscus idus in Norway. The flagellate was cultivated and studied by scanning and transmission electron microscopy. Identification was based on a suite of ultrastructural features unique for S. vortens: compound lateral ridges, a swirled posterior end, and a distinctive microtubular cytoskeleton. Microfibrillar structures with a periodicity of 0.13 microm in the right peripheral part of the compound lateral ridges were shown to be responsible for the distinctive rope-like appearance of the peripheral ridge seen in scanning electron micrographs, and not previously reported for S. vortens. The present results show a wide geographic distribution and a wide temperature tolerance for S. vortens. The flagellate was successfully cultivated at 5 degrees C and 15 degrees C, having previously been cultivated between 2-34 degrees C. Spironucleus vortens is believed to be endemic in Norwegian waters, but an introduction hypothesis is also discussed. The similarity is striking between S. vortens and S. elegans, previously described from amphibians and fish in Europe, and the possibility of conspecificity is believed to be high.

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PubMedDate not supplied

Cattle pathogen tritrichomonas foetus (Riedmüller, 1928) and pig commensal Tritrichomonas suis (Gruby & Delafond, 1843) belong to the same species.

A number of reports suggest that the sexually transmitted pathogen of cattle, Tritrichomonasfoetus, and a gastrointestinal commensal of pigs, Tritrichomonas suis, are very similar and may be co-specific. A conclusive review of the taxonomic and nomenclatural status of these species has not been presented so far. Toward this end, we reexamined and compared porcine and bovine trichomonads with regard to their morphology, pathogenic potential, and DNA polymorphism. Using light and electron microscopy, no distinguishing features between T. foetus and T. suis strains were found in size, general morphology, and karyomastigont structure. Both bovine and porcine trichomonads showed pathogenic potential in the subcutaneous mouse assays and did not separate into distinct groups according to strain virulence. Three DNA fingerprinting methods (i.e. RFLP, RAPD, and PCR-based analysis of variable-length DNA repeats) that produce species-specific DNA fragment patterns did not distinguish between the bovine and porcine strains. Sequencing of a variable 502-bp DNA fragment as well as comparison of 16S rRNA gene sequences did not reveal species-specific differences between the cattle and porcine strains. Therefore, we conclude that T. foetus and T. suis belong to the same species. To prevent confusion that may arise from T. foetus-T. suis synonymy, we propose to suppress the older name suis and maintain its accustomed junior synonym foetus as a nomen protectum for both cattle and porcine trichomonads. The case has been submitted to the International Commission on Zoological Nomenclature for ruling under its plenary power.

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PubMed1996

Intestinal parasitism--protozoa and helminths--in primates at the Barcelona Zoo.

The faunistic results regarding intestinal parasitism by protozoa and helminths in 21 primate species (three Cebidae, thirteen Cercopithecidae, one Hylobatidae, one Lemuridae, three Pongidae) are reported. The primate species were housed in four separate galleries. Six faecal samples of each host species were subjected to coprological analysis. Fifteen parasite species were detected: 11 protozoa (Entamoeba coli, E. chattoni, E. hartmanni, Iodamoeba bütschlii, Endolimax nana, Giardia intestinalis, Chilomastix mesnilii, Enteromonas hominis, Trichomonas intestinalis, Balantidium coli, and Blastocystis hominis) and 4 helminths (Ancylostoma sp., Strongyloides fuelleborni, Strongyloides sp., and Trichuris trichiura). The results reveal certain parasitic similarities between host species housed in the same gallery; however, these primate species do not always carry identical parasite species.

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PubMed1976

Polyarteritis nodosa associated with nosematosis in blue foxes.

The patho-morphological lesions in fox nosematosis (encephalitozoonosis) were studied in a material comprising 150 young blue foxes from 23 different farms. Disseminated nosematosis in blue fox pups was regularly accompanied by severe vasculitis, affecting medium-sized and small arteries in various organs. The acute damage has the form of a necrotizing angiitis, with mural necrosis and sometimes resultant thrombosis. The causative organism Nosema cuniculi, is frequently present in the freshly affected arterial walls, either in endothelial or in medial smooth muscle cells. Older lesions include nodular fibrous thickening of the arterial walls, and intimal proliferation, sometimes with luminal obliteration. The conclusion is drawn that the arterial lesions are morphologically equivalent to classical polyarteritis nodosa.

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PubMed1987

Brain and spinal cord lesions in encephalitozoonosis in blue foxes. Transmission and scanning electron microscopic studies.

The brains and spinal cords from 3 young blue foxes suffering from acute to subacute encephalitozoonosis, were examined by transmission and scanning electron microscopy. Parasitophorous vacuoles (PV) were demonstrated more frequently in vascular smooth muscular cells than in endothelial cells. The present study also indicated that the parasite has great affinity for neurons, including their processes. In addition, PV occurred in macrophages and probably also in intravascular monocytes. PV were readily differentiated from phagosomes by the bleb formations of the limiting membrane. An accumulation of host cell mitochondria near the PV in areas where developmental stages were attached, was a most striking feature. The inflammatory lesions, mainly of the granulomatous type, were almost constantly associated with the presence of released parasites, both in vascular walls and the nervous tissue. Phagocytosed parasites were probably killed by the lysosomal enzymes, although the spores were only slowly degraded.

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PubMed1988

Immuno-histochemical and ultrastructural characteristics of a cyst-forming sporozoon associated with encephalomyelitis and myositis in dogs.

Light-microscopy, including immuno-histochemical staining, and transmission and scanning electron microscopy were applied for the characterization of a Toxoplasma-like parasite associated with encephalomyelitis and myositis in dogs of the boxer breed. Most parasites were tachyzoites, occurring in clusters, up to 60 micron in diameter, in parasitophorous vacuoles of host cells. Cyst stages with a definite cyst wall were few, but could be demonstrated in all cases. Immunostaining with antiserum against Toxoplasma gondii was negative, while both tachyzoites and bradyzoites were stained with serum from affected dogs. Ultrastructurally, the parasite was characterized by a great number of rhoptries, few amylopectin granules, lack of micropores in the tachyzoites, and the occurrence of numerous dense bodies in the bradyzoites. Numerous intravacuolar tubules were present in the space of the parasitophorous vacuole. The cyst wall resembled that of T. gondii. Until a definite host is found, the parasite may be regarded as an "orphan", cyst-forming sporozoon that is ultrastructurally different from other known protozoan parasites. It has a light-microscopical similarity to T. gondii but is antigenically different.

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PubMed1976

Internal parasites of feral cats from the Tasmanian Midlands and King Island.

Eighty-six feral cats from a sheep grazing area in the Tasmanian Midlands and 21 from King Island were examined for internal parasites. Major food items in order of decreasing prevalence in stomach contents were insects, lizards, birds, rodents and frogs in the Midlands, and rodents, birds, insects, and lizards on King Island. Feral cats from the Midlands had 4 cestode, 7 nematode, 2 trematode and 3 protozoan parasites as follows: Spirometra erinacei (66.3%), Taenia taeniaeformis (2.3%), Dipylidium caninum (1.2%), Toxocara cati (86.0%), spiruroid nodules containing Cylicospirura felineus and Cyathospirura dasyuridis (57.0%), Ollulanus tricuspis (11.4%), Uncinaria stenocephala (2.3%), Aelurostrongylus abstrusus (39.2%), Capillaris aerophila (30.0%), Echinoparyphium sp (27.1%), Fibricola minor (6.8%), Isospora felis (12.7%), I. rivolta (5.4%), and Sarcocystis sp (1.8%). Antibodies to Toxoplasma gondii were found in 51 of 53 serums. Three cestode and 5 nematode parasites were found in cats from King Island: T. taeniaeformis (49.2%), D. caninum (23.8%), S. erinacei (19.0%), T. cati (90.5%), C. felineus (42.9%), C dasyuridis (9.5%), O. tricuspis (4.8%) and C. aerophila (9.5%). This is the first record of Cylicospirura felineus, Fibricola minor and Echinoparyphium sp in cats in Australia.

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