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PubMed1989

Characterization and immunolocalization of the protein contents of micronemes of Sarcocystis muris cystozoites (Protozoa, Apicomplexa).

Affinity-purified polyclonal antibodies generated against micronemes obtained by the subcellular fractionation of Sarcocystis muris contain two major proteins of 16 and 17 kDa. Antibodies cross-react with microneme antigen of S. tenella and S. cuniculi but not with the S. sp. of wild boar (Sus scrofa). Microneme antigens could be traced by immunoelectron microscopy in metrocytes as early as 47 days postinfection and in gamonts of S. muris in cell cultures up to 4 h after inoculation.

Animals↗
PubMed1994

The development of Hepatozoon sipedon sp. nov. (Apicomplexa: Adeleina: Hepatozoidae) in its natural host, the Northern water snake (Nerodia sipedon sipedon), in the culicine vectors Culex pipiens and C. territans, and in an intermediate host, the Northern leopard frog (Rana pipiens).

The life cycle of Hepatozoon sipedon sp. nov. was studied in two snake species, the Northern water snake and the Eastern garter snake, in its mosquito hosts Culex pipiens and C. territans, and in the Northern leopard frog. Gametogenesis, fertilization and sporogony occurred within fat body cells in the haemocoel of mosquitoes that had fed on infected water snakes. Mature oocysts averaging 263 microns in diameter and containing more than 500 sporocysts were observed in mosquitoes 28 days post-feeding. Each sporocyst enclosed eight sporozoites. Dizoic cysts were found in the liver of frogs that had been fed infected mosquitoes seven days previously. Two rounds of merogony in various internal organs and intraerythrocytic gamonts were observed in snakes that had been fed frogs which had been orally inoculated with infected mosquitoes. Developmental stages were not seen in snakes that were fed infected mosquitoes directly. A comparison of this life cycle with those described for other Hepatozoon species infecting snakes is presented with reference to the different modes of transmission featured by these parasites.

Animals↗
PubMed1985

Intergeneric interactions between Eimeria separata (Apicomplexa) and Nippostrongylus brasiliensis (Nematoda) in the rat.

Ova production in Nippostrongylus brasiliensis infected rats was significantly greater than in rats singly infected with the helminth when Eimeria separata infections were introduced 4, 6 and 11 days postinoculation with N. brasiliensis. Patent periods were unaltered during concurrent infections. These results suggest that the presence of E. separata affects helminth fecundity but does not increase N. brasiliensis longevity as has been shown with E. nieschulzi.

Animals↗
PubMed2000

Observation of sutures in the oocyst wall of Eimeria tenella (Apicomplexa).

Eimeria tenella is the causative agent of caecal coccidiosis in chicken. Infection of chicken is initiated by ingestion of sporulated oocysts. The oocyst wall has two typical layers: a smooth outer layer formed by wallforming body I (WF I) and an inner layer originating from WF II. We observed that the inner layer is circumscribed by a hitherto undocumented linear suture and propose its role in the process of infection.

Animals↗
PubMed2001

Fine structure of sporogonic stages of Goussia clupearum (Apicomplexa: Eimeriidae) in the liver of infected fish (Belone belone L.), using light and electron microscopy.

A coccidian species, Goussia clupearum (L.) is reported to parasitize the liver of a new host, Belone belone (Teleostei: Belonidae), caught on the Atlantic coast at the north of Portugal. The parasitophorous vacuole containing oocysts was attached to the host's liver cells. Spherical oocysts (approximately 21.2 microm diameter), each containing four ellipsoidal elongated sporocysts (10.5 x 6.3 microm), were enclosed in the parasitophorous vacuole. Each sporocyst contained two sporozoites. The micropyle was absent, but a polar granule (without Stieda body) was present. Each sporozoite possessed four refractile bodies. During sporoblastogenesis and sporogenesis, one or two dense polar bodies were found within the oocysts. They were composed of a dense homogeneous core, surrounded by a ring of dense granular material. On occasion, we observed some sporocysts in direct contact with host cells. This paper describes the morphology and ultrastructural details of the oocysts, sporocysts and sporozoites of G. clupearum. This species seems to represent the only coccidium described in fish from this Atlantic coast.

Animals↗
PubMed2002

Monoclonal antibodies specific for the two types of wall-forming bodies of Eimeria tenella macrogametes (Coccidia, Apicomplexa).

Two monoclonal antibodies (mAbs) raised against the macrogamonts of Eimeria tenella identified antigens located in the wall-forming bodies of type I (WF I) and type II (WF II) by indirect immunofluorescence and by immunoelectron microscopy. With these mAbs, the involvement of both types of wall-forming body at the protein level in the formation of the inner and outer oocyst walls of E. tenella was shown by indirect immunofluorescence assay. On Western blots of pure macrogamont, mAb E1D8 against WF I reacted with a series of bands between 42 kDa and 105 kDa. In pure, unsporulated extract, this mAb recognized a complex of bands between 26 kDa and 153 kDa. mAb E2E5 against WF II, on Western blots of pure extract of macrogamonts, recognized an antigen of 51 kDa. Later in the development, after the formation of the inner oocyst wall, mAb E2E5 reacted with three polypeptide of 23, 25 and 30 kDa. Proteolytic processing may be forwarded as the mechanism regulating the distinct regulation protein involved in the oocyst wall.

Animals↗
PubMed2003

Cloning, sequencing and recombinant expression of the open reading frame encoding a novel member of the Sarcocystis muris (Apicomplexa) microneme lectin family.

Micronemes are characteristic secretory organelles located within the apical cell region of apicomplexan parasites. The protein contents are exocytosed during an early phase of host cell invasion and contribute to parasite motility and the invasion of target cells. We report here on the cloning and heterologous expression of a novel member of the Sarcocystis muris microneme lectin family. The deduced amino acid sequence is in total agreement with that obtained after sequencing the native protein and is characterized by two copies of the apple domain motif. The recombinant polypeptide is expressed in a biologically active conformation as demonstrated by its galactose binding properties.

Amino Acid Sequence↗
PubMed2003

Comparative development of Eimeria tenella (Apicomplexa) in host cells in vitro.

Attempts to propagate Eimeria tenella in cell culture over the years have met with limited success. The host cell type is an important parameter in such cultures. This study assessed the ability of different host cell lines to support E. tenella infection in vitro. The initial development in cell lines and the effects of incubation at 37 degrees C and 41 degrees C on the host-parasite relationship was investigated. Eleven cell lines were seeded into 96 well plates and incubated at 37 degrees C in 5% CO(2) to reach confluency. Sporozoites of E. tenella were inoculated into wells and allowed to invade at 37 degrees C and 41 degrees C. Intracellular parasite development was quantified using (3)H-uracil incorporation. All cell lines facilitated parasite invasion and development. The MDBK cell line supported the highest degree of E. tenella development. A time-course study was undertaken to look at this host cell-parasite relationship during infection.

Animals↗
PubMed2003

Experimental transmission of Cryptosporidium molnari (Apicomplexa: Coccidia) to gilthead sea bream (Sparus aurata L.) and European sea bass (Dicentrarchus labrax L.).

Cryptosporidium molnari was experimentally transmitted to gilthead sea bream (Sparus aurata) and European sea bass (Dicentrachus labrax) by oral infection with infected stomach scrapings. The infection was also cross-transmitted from infected gilthead sea bream to sea bass by cohabitation. The course of the infection was assessed after necropsy by three microscopic diagnostic methods and their sensitivity was compared. At the end of all the experiments the prevalence of infection reached 100%. In the oral experiments, both fish hosts appeared infected as early as 7 days post exposure (p.e.), but gilthead sea bream exhibited a higher intensity of infection and infection proceeded at a faster rate than in sea bass. The cellular host reaction was stronger in sea bass than in sea bream, whereas the histopathological effect was lower in the former. Transmission could be favoured by cannibalism among cohabiting fish. This is the first report on piscine Cryptosporidium transmission. The implications for the aquaculture industry are discussed.

Animals↗
PubMed2004

The first report of Hepatozoon spp. (Apicomplexa, Hepatozoidae) in domestic cats from São Paulo state, Brazil.

Hepatozoon sp. was diagnosed in three naturally infected cats from São Paulo state, Brazil. The first animal was admitted to the veterinary clinic with renal failure. During the hematological examination, gamonts of Hepatozoon sp. were observed within polymorphonuclear cells. Another two cats, which lived in the same house as the first cat, were also positive for this hemoparasite. This is the first report of a Hepatozoon sp. infection in domestic cats from Brazil.

Animals↗
PubMed2006

Three new species of coccidia (Apicomplexa: Eimeriorina) from the Marble-throated skink, Marmorosphax tricolor Bavay, 1869 (Reptilia: Scincidae), endemic to New Caledonia with a taxonomic revision of Eimeria spp. from scincid hosts.

Three new species of coccidia are described from Marble-throated skink Marmorosphax tricolor from New Caledonia, namely, Isospora bocagei sp. n., Acroeimeria rouxi sp. n., and Choleoeimeria sadlieri sp.n. All species differ markedly from other eimerian coccidia described from scincid hosts. Isospora marmorosphaxi develops extra-nuclearly in small intestine. A. rouxi develops epicitoplasmatically in small intestine. C. sadlieri affects the gall bladder mucosa. Generic affiliation of Eimeria-like coccidia from reptiles is discussed and all taxa (with adequate information on endogenous development available) from scincid hosts are revised and placed into genera Acroeimeria and Choleoeimeria.

Animals↗
PubMed2005

Two new species of Eimeria Schneider 1875 (Apicomplexa: Eimeriidae) from the broad-toothed field mouse, Apodemus mystacinus Danford and Alston 1877 (Rodentia: Muridae) from Jordan.

Coprological examination of 40 Apodemus mystacinus Danford and Alston 1877 from Jordan revealed oocysts of three species of genus Eimeria. Two species are described as new. Eimeria zuhairamri sp. n. has broadly ellipsoidal oocysts 29.6 (27.0-34.0) x 23.3 (22.0-25.0) mum with distinctly granulated wall and oocyst residuum. Endogenous development occurs in jejunum and ileum. Eimeria alorani sp. n. has oocysts 26.9 (23.0-29.0) x 19.3 (18.0-22.0) mum with smooth wall and absent residuum. Endogenous development is confined to the caecum. The third species, developing in jejunum, has oocysts morphologically indistinguishable from Eimeria uptoni. The identity of E. uptoni and the taxonomy of Eimeria of Apodemus are discussed.

Animals↗
PubMed2006

Endogenous development, pathogenicity and host specificity of Eimeria cahirinensis Couch, Blaustein, Duszynski, Shenbrot and Nevo, 1997 (Apicomplexa: Eimeriidae) from Acomys dimidiatus (Cretzschmar 1826) (Rodentia: Muridae) from the Near East.

Eimeria cahirinensis Couch et al. 1997 was found in faecal samples of Acomys dimidiatus from three different localities in the Near East. Twenty-two of 104 (21%) A. dimidiatus trapped on both the south- and north-facing slopes of "Evolution Canyon", Lower Nahal Oren, Mt. Carmel, Israel in August 2001 and 2002 were infected with E. cahirinensis. Oocysts were also obtained from a single individual of A. dimidiatus trapped in Wadi Ramm, Jordan in the summer of 1999. Laboratory-reared spiny mice (Acomys spp.) were inoculated to determine the prepatent and patent period, sporulation time, site of infection, immunogenicity, pathogenicity, pathology and morphology of endogenous stages of E. cahirinensis. Both asexual and sexual stages were localised in the apical part of duodenal and jejunal villi. An experimental inoculation of representatives of several rodent genera revealed the host range of E. cahirinensis to be limited to the genus Acomys.

Animals↗
PubMed2006

The relative stability of chronic Isospora sylvianthina (Protozoa: Apicomplexa) infection in blackcaps (Sylvia atricapilla): evaluation of a simplified method of estimating isosporan infection intensity in passerine birds.

Estimation of intensity of coccidia infection in wild birds is essential for the studies of the parasite impact on birds' natural populations. In this paper I propose a method for quantification of coccidia oocyst output from passerine birds applicable in field investigations because it is based on one faeces droplet per bird only. This method was checked under controlled laboratory conditions on blackcaps, chronically infected with Isospora sylvianthina, and was proved to be sensitive enough for the detection of between-individual differences in parasite load. I also show that individual variation in the intensity of isosporan infection in captive blackcaps is relatively stable in time, both in the scale of a few consecutive hours and in that of consecutive days. Hence, the study shows that, in passerine birds, single measurements of oocyst production, when collected in the proper time of day, can be used to characterise some more permanent aspects of an individual's coccidia infection status.

Animals↗
PubMed2000

Life-cycle of Isospora mehlhornii sp. nov. (Apicomplexa : Eimeriidae), parasite of the Egyptian swallow Hirundo rubicola savignii.

Fifty-seven Hirundo rubicola savignii swallows were collected from Damietta, Tanta, Dakahlyia and Sharkia Provinces, Egypt. They were examined for coccidian parasites. The percentage of infection with Isospora stages was 12.3%. After diagnosis it was noted that the parasites belong to a new species. The unsporulated oocysts were spherical, measuring 25.7-31.9 microm in diameter with a mean of 28.3 microm. A micropyle, polar granule and oocyst residuum were absent. Sporocysts appeared lemon-shaped and measured 19.6-24.5 microm x 12.5-17.5 microm with a mean of 22.9 x 14.4 microm. Stieda body and the sporocyst's residual body were clearly visible. Sporozoites measured 11-14.2 x 4.4-5.1 microm with a mean of 11.4 x 4.7 microm. Sporulation time was 72 h at room temperature (25 degrees C). Endogenous stages including schizogony and gamogony were detected in epithelial cells of the duodenum, jejunum and ileum of the host. Schizogony consisted of two generations. Mature first generation schizonts reached up to 11 microm in diameter and produced merozoites measuring 3.5 x 1.7 microm. Mature second generation schizonts measured 17.2 x 12.3 microm and produced merozoites measuring 11.8 x 2.2 microm. Gamogonic stages were differentiated into microgamonts and macrogamonts. Mature microgamonts were spherical and measured 23.2 microm in diameter, producing curved microgametes measuring 4.5 x 0.7 microm. The ovoid macrogametes measured 19.6 x 14.7 microm and were characterized by a large nucleus and nucleolus. Early, more or less spherical, oocysts were detected inside the intestinal epithelial cells and in the intestinal lumen. They measured 19.6 microm in diameter. The sporont measured 17.2 microm in diameter. Cytochemical studies on schizogony, gamogony and oocysts were accomplished and showed distribution of polysaccharides and composition of the oocyst wall.

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