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PubMed2004

Cryptosporidium scophthalmi n. sp. (Apicomplexa: Cryptosporidiidae) from cultured turbot Scophthalmus maximus. Light and electron microscope description and histopathological study.

Cryptosporidium scophthalmi n. sp. is described from the turbot Scophthalmus maximus L., sampled from different farms on the coast of NW Spain. The parasite was found mainly in the intestinal epithelium and very seldom in the stomach. Oocysts were almost spherical, with 4 naked sporozoites and a residuum, and measured 3.7-5.03 x 3.03-4.69 microm (mean 4.44 x 3.91) (shape index 1.05-1.34, mean 1.14). Sporulation was endogenous, as fully sporulated oocysts were found within the intestinal epithelium, lumen and faeces. Merogonial and gamogonial stages were in the typical extracytoplasmic position, whereas sporogonial stages were deep within the epithelium. Oocysts and other stages of C. scophthalmi comply with most of the diagnostic features of the genus Cryptosporidium, but differ from all hitherto described species. Ultrastructural features, including the characteristic feeding organelle, were mainly comparable with those of other Cryptosporidium species. Mitochondria were frequently observed in sporozoites. Infection prevalence was very variable, and juvenile fish were most frequently and intensively parasitised. External clinical signs were not detected, although some fish showed intestinal distension at necropsy. The marked histopathological damage occurring in severe infection includes distension of epithelial cells by large vacuoles, containing clusters of oocysts, and can lead to sloughing of epithelial cell remnants and oocysts or even detachment of intestinal mucosa. An inflammatory reaction involving leucocyte infiltration was sometimes observed.

Analysis of Variance↗
PubMed2005

Occurrence of Perkinsus olseni (Protozoa: Apicomplexa) and other parasites in the venerid commercial clam Pitar rostrata from Uruguay, southwestern Atlantic coast.

A study was conducted into the health status of natural populations of the venerid clam Pitar rostrata from Uruguay. Perkinsus sp. was detected in 22% of the clams. Severe hemocytic infiltration was detected in the tissues parasitized by this protozoan parasite. The sequencing of the ITS-5.8S gene cluster of the parasite confirmed that it belonged to the Perkinsus olseni species. Rickettsia or Chlamidia-like organisms were also found, with a prevalence of 11%, although without apparent host reaction; an unidentified species of Coccidia was found in the nephridia of 78% of the clams, with the intensity of infection ranging from moderate to high. A gregarine, Nematopsis-like organism was observed mainly in the epithelial cells of the intestine, without host response and with a prevalence of 56%. Of the metazoan parasites, trematodes were found in 11% of the individuals analyzed.

Animals↗
PubMed2006

Extra-intestinal localization of Goussia sp. (Apicomplexa) oocysts in Rana dalmatina (Anura: Ranidae), and the fate of infection after metamorphosis.

Although coccidia of the genus Goussia are common parasites of fish, only 2 species have been described in amphibians: G. hyperolisi from common reed frogs Hyperolius viridiflavus from Kenya and G. neglecta from unspecified European water frogs of the genus Rana from Germany. The genus Goussia is characterized by an oocyst, with a fine oocyst wall, containing 4 dizoic sporocysts that are composed of 2 valves joined by a longitudinal suture and lacking a Stieda body (typical for the genus Eimeria). To date, infections in amphibians were generally considered to be specific to the intestine of aquatic larval stages (tadpoles) of anurans. Herein, we report on: (1) the presence of oocysts of Goussia sp. in an extra-intestinal location (liver) of tadpoles of the agile frog R. dalmatina and (2) the presence of oocysts in the liver of both juvenile and subadult R. dalmatina. These observations represent novel traits for Goussia infections in amphibians; they may explain the vertical transmission of Goussia in tadpoles.

Animals↗
PubMed2006

Ultrastructural aspects of hepatic coccidiosis caused by Goussia lusca n. sp. (Apicomplexa: Coccidia) infecting Trisopterus luscus (Gadidae) from the NE Atlantic Ocean.

Goussia lusca n. sp. is described from the liver of pouting Trisopterus luscus from the NE Atlantic Ocean in Ibero-Atlantic Portuguese and Spanish waters. Mature oocysts were 31.7 (28.8 to 35.4) microm in diameter. Each oocyst contained 4 ellipsoidal sporocysts arranged in an aleatory position, and measuring approximately 13.7 x 9.2 microm. Each sporocyst contained 2 sporozoites. Ultrastructurally, the sporocyst wall consisted of a dense inner layer 115 nm thick, transversely striated, regularly intercalated by thin grooves with electron-lucent spaces, and separated from the outer layer by a thin, light (electron-lucent) space. The outer layer was multilamellated and consisted of parallel dense bands alternating with light spaces. These lamellae formed filamentous extensions of the wall. The dehiscence suture, a characteristic feature of the genus, was present in the sporocysts. No external clinical signs were observed in the host fish. Parasites observed in the liver tissue were often enveloped in a yellowish-brown matrix, generally known as 'yellow bodies'. Sometimes sporocysts were observed in direct contact with the liver cells. Parasites in degeneration and aggregations of amylopectin granules were frequently observed surrounded by host inflammatory cells. In severe infections, we observed large agglomerations of oocysts encapsulated by layers of concentrically arranged connective tissue forming large granulomas, which caused significant replacement of the host liver parenchyma by the parasite.

Animals↗
PubMed1987

Ultrastructure of Sarcocystis spp. (Protozoa: Apicomplexa) in rodents from North Sulawesi and West Java, Indonesia.

Tissue cysts of the protozoan genus Sarcocystis were detected in the skeletal muscles of 16 (40%) of 40 wild rodents captured in North Sulawesi and West Java, Indonesia. Two types of cysts were found to differ in their morphological characteristics. Macroscopic and microscopic cysts bounded by thick radially-striated cyst walls were detected at both locations in a total of 13 rodents belonging to seven different species (Bunomys chrysocomus, B. fratrorum, Maxomys bartelsii, M. musschenbroekii, Paruromys dominator, Rattus xanthurus and R. exulans). The primary cyst walls contained numerous broad spatula-like protrusions and the cysts were identified as S. singaporensis Zaman and Colley, 1976. In contrast, microscopic cysts bounded by thin smooth cyst walls were detected in seven rodents belonging to three different species captured at Toraut in North Sulawesi (B. chrysocomus, B. fratrorum and P. dominator). Ultrastructural examination revealed numerous slender hair-like protrusions of their primary cyst walls. It is proposed that these cysts be named S. sulawesiensis sp. n. on the basis of their unique morphological characteristics, their intermediate host range and their limited geographic distribution. Mixed infections by both species were found in three rodent species (B. chrysocomus, B. fratrorum and P. dominator).

Animals↗
PubMed1988

Eimeria wobeseri sp. n. and Eimeria goelandi sp. n. (Protozoa: Apicomplexa) in the kidneys of herring gulls (Larus argentatus).

Eimeria wobeseri sp. n. and E. goelandi sp. n. from the kidneys of nestling herring gulls (Larus argentatus) are reported. Species descriptions are based on the morphology of sporulated oocysts. Oocysts of one or both species were recovered from 90 to 100 gulls. Nine of 16 gulls rigorously examined were found infected simultaneously with both species. Meronts, gamonts and zygotes were observed histologically in epithelial cells of distal tubules, collecting ducts and ureters. Sporulated oocysts with thin walls and micropylar caps were present within or near collecting ducts and were identified as E. goelandi sp. n. An electron-lucent outer layer and electron-dense inner layer of the oocyst wall, the ultrastructure of the oocyst wall at the micropylar cap and endogenous sporulation of E. goelandi sp. n. are unique observations for a member of the genus Eimeria.

Animals↗
PubMed1993

Enteric coccidia (Apicomplexa) in the small intestine of the northern spotted owl (Strix occidentalis caurina).

Sporulated oocysts (mean dimensions = 13.0 x 10.8 microns) and sporocysts (11.3 x 5.5 microns) of a coccidian resembling Frenkelia sp. or Sarcocystis sp. were present in the lamina propria of the small intestine of a naturally-infected northern spotted owl (Strix occidentalis caurina) collected near Medford, Oregon (USA). Dimensions of these oocytes and sporocysts appear to be considerably smaller than those from other sarcocystid species with avian definitive hosts. Additionally, numerous developmental stages and unsporulated oocysts (mean dimensions 22.8 x 17.8 microns) of a possible species of Isospora also were observed in the intestinal epithelium. This constitutes the first report of enteric coccidia from spotted owls. Neither parasite appeared to cause the death of the bird.

Animals↗
PubMed1994

A new coccidian (Apicomplexa: eimeriidae) in the northern pocket gopher (Thomomys talpoides) and a comparison of oocyst survival in hosts from radon-rich and radon-poor soils.

Forty (93%) of 43 northern pocket gophers (Thomomys talpoides) from the Jemez Mountains, Sandoval County, New Mexico (USA), had coccidian oocysts in their feces when examined. We describe this parasite, Eimeria jemezi, n. sp. Sporulated oocysts were subspheroidal, 13.3 by 12.2 (10 to 17 by 9 to 15) microns, with sporocysts ellipsoidal, 7.1 by 4.4 (5 to 9 by 4 to 5) microns; micropyle and oocyst residuum were absent, but polar bodies, Stieda bodies and sporocyst residua were present. All gophers were collected from two sites of similar habitat 7 km apart. One site (R+) had a high soil radon content (> or = 50 to 70 picocuries (pCi) per liter of air) whereas the other site (R-) had soils that were near average natural levels (1.2 to 1.6 pCi/g uranium nucleotides per gram of soil; < 1.9 pCi/g thorium nucleotides). Twenty-one (88%) of 24 gophers from the R+ site had coccidian oocysts in their intestines when examined, but none of these oocysts ever sporulated, whereas all 19 (100%) gophers from the R- site had coccidian oocysts in their intestines and 16 (84%) of these samples sporulated normally under laboratory conditions. The elevated radon content of the soil may have had an adverse effect on the sporulation of this coccidian while it still was intracellular within its host.

Animals↗
PubMed2003

Natural infection of Cryptosporidium muris (Apicomplexa: Cryptosporiidae) in Siberian chipmunks.

Coprologic examination of nine Siberian chipmunks (Eutamias sibiricus) imported from Southeast Asia revealed infection with Cryptosporidium sp. Experimental inoculation of BALB/c mice proved their susceptibility to the infection. Infected mice shed oocysts 14-35 days postinfection. Oocyst morphology was similar to that reported for C. muris in previous studies, oocysts were 8.1 (7.0-9.0) x 5.9 (5.0-6.5) microns. Clinical signs were absent in naturally infected chipmunks and experimental mice. Histologic examinations of mice revealed numerous developmental stages of C. muris in the glandular stomach. Analysis of partial small subunit rRNA gene sequences confirmed identity of these isolates as C. muris. Our results represent the first report of C. muris in members of the family Sciuridae.

Animals↗
PubMed2005

Eimeria species (Apicomplexa: Eimeriidae) infecting Eliomys quercinus in an Alpine habitat.

Coccidian parasites were detected in an Alpine population of the garden dormouse (Eliomys quercinus), and 55-82% of the fecal samples collected during a two-year study (2000 and 2002) contained one or two eimerian species. We report the presence of Eimeria myoxi and confirm for the first time the presence of Eimeria melanuri in the garden dormouse. These Eimeria species can be considered common parasites of the garden dormouse and the Asian garden dormouse. The high prevalence might be due to group hibernation by the dormice.

Animals↗
PubMed2005

Experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of Hepatozoon americanum (Apicomplexa: Adeleorina).

Each of five adult and four juvenile coyotes (Canis latrans) was exposed to an oral dose of 50 Hepatozoon americanum oocysts recovered from Amblyomma maculatum ticks that previously fed on either naturally infected domestic dogs (Canis familiaris) or naturally infected wild coyotes. All coyotes exposed to H. americanum became infected, regardless of isolate source, and all exhibited mild to moderate clinical disease that simulated American canine hepatozoonosis in naturally infected dogs. At 100 days postexposure, parasitemia was greater in juvenile than adult coyotes (0.9% and 0.3%, respectively); radiographic imaging of femurs revealed moderate exostosis in all juveniles and mild to moderate new bone growth in four of five (80%) adult coyotes. Gross postmortem analysis of bone lesions demonstrated variation between age groups of coyotes but not between isolates of H. americanum. Microscopic evaluation of skeletal muscle revealed that parasite-induced lesions were significantly more numerous (t = 5.0, df = 7, P = 0.001) in juvenile than adult coyotes. Results of this study indicate that juvenile and adult coyotes are equally susceptible to experimental infection with H. americanum isolated from domestic dog and wild coyote sources. The age of coyotes at the time of exposure, and possibly the number of H. americanum oocysts ingested, might influence morbidity and mortality, but it appears that both adult and juvenile coyotes could be reservoirs of H. americanum.

Age Factors↗
PubMed1999

Prevalence of Eimeria macusaniensis (Apicomplexa: Eimeriidae) in midwestern Lama spp.

To compare the prevalence of Eimeria macusaniensis among midwestern llamas (Lama glama), alpacas (Lama pacos), and guanacos (Lama guanicoe), feces were obtained from Lama spp. in 10 states between October 1989 and February 1996. Feces were examined by centrifugal flotation in sugar solution (specific gravity--1.28-1.30), and oocysts were quantified by a modified McMaster method. Data were compared by host species and age classifications. Typical oocysts occurred in samples from 28% of 76 herds and 10.4% of 443 animals including 12% of 301 llamas, 7% of 115 alpacas, and 7.4% of 27 guanacos. Prevalence was significantly greater (P = 0.009) in animals < 1 yr of age in comparison to older animals for llams (22.1 v.s. 8.5%) and for all Lama spp. combined (17.1 vs. 8.4%). Fecal oocyst abundance was significantly greater (P = 0.001) in llamas < 1 yr of age in comparison to older llamas (30 vs. 16 oocysts per g of feces). Fecal oocyst intensities did not differ significantly. Prevalence in both age groups of midwestern llamas was greater than previously reported for llamas in the western United States. Prevalence in midwestern alpacas < 1 yr of age was lower than reported for alpacas of similar age in South America, but oocyst intensities were similar. These results indicate that infection with E. macusaniensis is more common in Lama spp. in North America than previously recognized.

Animals↗
PubMed1999

Two new species of coccidia (apicomplexa: Eimeriidae) from the bearded false chameleon Chamaeleolis barbatus (Sauria: polychridae) from cinco pesos, Pinar Del Río, Cuba.

Parasitological examination of bearded false chameleons Chamaeleolis barbatus freshly imported from Cuba revealed the presence of 2 species of coccidia that are described as new. Oocysts of Isospora chamaeleolidis n. sp. are spherical to slightly subspherical, 16.1 (13-21) x 15.6 (13-19) microm, with a brownish and bilayered wall approximately 1.0-1.5 microm thick; outer layer markedly pitted. 0.75-1.0 microm thick. One, rarely 2, globular polar granules, 1.5 in diameter are present in the sporulated oocysts. Sporocysts are ellipsoidal, 10.8 (10-13) x 7.8 (7-9) microm, with a smooth, colorless, and unilayered sporocyst wall. Stieda body and substieda bodies are present. A sporocyst residuum is present, consisting of small granules of irregular size scattered among the sporozoites. Oocysts of Eimeria chamaeleolidisbarbati n. sp. are broadly oval, 19.0 (17-21) x 15.7 (15-17) microm, with a bilayered, colorless oocyst wall approximately 0.75 thick; outer layer of oocyst wall is smooth, 0.5 microm thick. One or 2, rarely 4, globular, irregular polar granules, approximately 1.5 microm in diameter, are present in sporulated oocysts. Sporocysts are broadly oval, 7.4 (7-8.5) x 6.1 (5.5-7) microm, with a smooth, colorless, and unilayered sporocyst wall, composed of 2 valves joined by suture; Stieda body and substieda bodies are absent.

Animals↗
PubMed1999

[Current views on the life cycle of cyst-forming Coccidia (Eucoccidia, Sporozoa, Apicomplexa)].

The life cycles of cyst-forming coccidia of the genera Sarcocystis and Toxoplasma have been first analysed in terms of generally recognized biological phenomena, such as proliferation, differentiation, dedifferentiation, programmed cell death. The differences, existing between the respective obligatory heteroxenous (Sarcocystis) and facultatively heteroxenous (Toxoplasma) life cycles, have been found to involve the obvious differences in the degree of a zoite's differentiation, occurring in the course of asexual development in the intermediate host. In Sarcocystis spp., the degree of differentiation in merozoites, throughout their development, is much higher than in those of T. gondii. This level of merozoite differentiation in Sarcocystis is thought to determine the irreversible, one-directional way of both pre-cystic and cystic development of the pathogen, starting from the sporozoite stage and terminating in gamont formation within the tissue cyst. Unlike, in T. gondii, the level of merozoite differentiation is not so strong as in Sarcocystis spp., which may account for the reversible merozoite development in the former, which is clearly demonstrated by a ready conversion of pre-cystic tachyzoites into cystic bradyzoites, and the other way round. In the course of endogenous development, the pathogens adversely affect their environment (the infected cells and tissues), which, in its turn, may exert its influence on the particular parasites. Thus, both the parasite and the host represent a unique feed-bach regulatory system.

Animals↗
PubMed1999

Sporogonic development of Hepatozoon americanum (Apicomplexa) in its definitive host, Amblyomma maculatum (Acarina).

Light microscopic observations of the sporogonic development of Hepatozoon americanum are described in its acarine host, Amblyomma maculatum. Laboratory-reared nymphal ticks were fed on 2 dogs infected with H. americanum. Nymphal ticks were sampled daily, starting 3 days after being placed on a parasitemic dog, until 18 days after infestation (PI), and then every 3 or 4 days until replete nymphs molted. Ticks were examined as unstained wet mounts and hematoxylin-eosin-stained paraffin sections. Gametes were found within the gut cells of nymphs 4 and 6 days PI. Although differentiation of gamonts into gametes was not detected, syngamy and sporogony were observed. Sporogony appears to occur wholly within tick gut cells, followed by release of mature oocysts into the hemocoel. The earliest evidence of sporoblast formation was observed 23 days PI and of sporozoite formation, 10 days later. Mature oocysts were first found 42 days PI in newly molted adult ticks. Most adult ticks (>98%) that were dissected contained mature oocysts. Oocysts were multisporocystic, and sporocysts contained a variable number of sporozoites. Oocysts in various stages of development were often seen within the same tick, and the number of mature oocysts ranged from 4 to 573.

Animals↗
PubMed2002

A new coccidian parasite (Apicomplexa: Eimeriidae) from the scimitar-horned oryx, Oryx dammah.

Oocysts of Eimeria oryxae sp. n. are described from the faeces of the scimitar-horned oryx, Oryx dammah (Cretzschmar, 1826), from Zoo Garden, Riyadh City, Saudi Arabia. Sporulated oocysts were ellipsoid in shape measuring 20.9 x 17.1 (16.7-24.2 x 15.5-20.2) microm, with smooth brownish-yellow double layered wall. Micropyle and ellipsoidal polar granules are present, but micropylar cap and oocyst residuum are absent. Sporocysts are ovoid, reaching 10.0 x 5.7 (9.2-11.0 x 5.2-6.5) microm with Stieda body and sporocyst residuum. Sporozoites are elongated, each with large and small refractile body.

Animals↗
PubMed2002

The ultrastructural study of microgametogenesis of Eimeria scinci Phisalix 1923 (Apicomplexa: Eimeriidae) infecting the sandfish lizard, Scincus mitranus Anderson 1871 in Saudi Arabia.

The ultrastructure of microgametogenesis of Eimeria scinci Phisalix 1923 was described for the first time in the gall bladder epithelium of experimentally infected sandfish lizards, Scincus milranus Anderson 1871 from Al-Baha region in Saudi Arabia. Recorded sequence of events started as sexually differentiated second generation merozoites transformed into microgamonts, where most of the apicomplexan organelles have been disappeared gradually. Microgamonts were recognizable by the presence of peripherally arranged nuclei and the presence of one or two centrioles between each nucleus and the limiting membrane of the gamont. Early microgamonts were surrounded by a very narrow parasitophorous vacuoles, which widened during development and contained a few intravacuolar folds and tubules. Differentiation of microgametes began by elevations of the limiting membrane appeared above the centrioles and the segregation of nuclear content into a dense osmiophilic portion and an electron-pale one. A gradual protrusion of the dense portion of the nucleus and the developing flagella into the parasitophorous vacuole was proceeded. Fully developed microgametes become detached and occupied the parasitophorous vacuole along with the residual body of the mother microgamont. Each microgamete had at least two flagella; an anterior perforatorium; a dense elongate nucleus and an anteriorly located tubular mitochondrion. The (9x2+2) pattern of flagella was detected in transverse sections.

Animals↗