Ponazuril inhibits the development of Eimeria vermiformis in experimentally infected outbred Swiss mice.

We evaluated a 15% paste formulation of ponazuril in outbred Swiss mice that were experimentally infected with Eimeria vermiformis. Thirty, 8-week-old female mice (approximately 20 g) were placed in one group of 10 mice and one group of 20 mice. Mice in both groups were gavaged with approximately 5,000 sporulated oocysts of E.

Major histocompatibility complex class I- and II-deficient knock-out mice are resistant to primary but susceptible to secondary Eimeria papillata infections.

Two distinct mechanisms seem to function in reducing oocyst output during Eimeria papillata infections in mice. For naive mice, immunity was afforded by a T-cell-independent gamma-interferon (IFN-gamma) response mediated by natural killer (NK) cells. On reinfection, resistance was associated with T-cells and, to a lesser extent, perforin.

Cellular dynamics and cytokine responses in BALB/c mice infected with Eimeria papillata during primary and secondary infections.

BALB/c mice were infected with the intestinal intracellular parasite Eimeria papillata to characterize lymphocyte responses and cytokine profiles throughout primary and secondary infections. Lymphocytes from the mesenteric lymph node (MLN) and the gastrointestinal tract (GIT) of infected mice were phenotypically analyzed using flow cytometry and immunofluorescence microscopy, respectively. Lymphocytes isolated from the MLN during primary infections of BALB/c mice with E.

Comparison of four murine Eimeria species in immunocompetent and immunodeficient mice.

Factors associated with immune-mediated protection against coccidial parasites were examined in a series of experiments utilizing immunocompromised scid/scid(SCID) and scid/scid.beige/beige(SCID/Bg) mice, as well as immunocompetent BALB/c mice. Number of oocysts produced per g feces each day and prepatent and patent periods were assessed for 4 eimerian parasites (Eimeria papillata, Eimeria vermiformis, Eimeria falciformis, and Eimeria ferrisi) using the 3 murine strains.

Ultrastructural observations of host-cell invasion by sporozoites of Eimeria papillata in vivo.

Scanning and transmission electron microscopy were used to study the invasion of mouse small-intestinal epithelium by sporozoites of Eimeria papillata. Some mice received oocysts by gavage and others received either sporocysts or sporozoites by direct injection into the small intestine. The highest concentration of invaded cells were found in ligated intestinal tissues studied at 5-45 min after the inoculation of sporozoites.

Scanning and transmission electron microscopy of host cell pathology associated with penetration by Eimeria papillata sporozoites.

Scanning and electron microscopy was used to study the pathogenesis that occurred in mouse epithelial cells that had been penetrated by Eimeria papillata sporozoites. Optimal penetration of parasites injected into nonligated and ligated mouse intestine was found to occur at 4-15 min post-inoculation. During initial penetration, the parasite caused disruption of the microvilli of the intestinal cells, which led to detachment of the microvilli from the plasma membrane of the penetrated cell.

A freeze-fracture study of the host cell-parasite interface during and after invasion of cultured cells by cystozoites of Sarcocystis muris.

The parasite-host-cell interface of Sarcocystis muris in cell culture was studied by freeze-fracture electron microscopy. Cystozoites of S. muris have an intra membrane particle (IMP) density of 1347 ± 146 IMP/μm(2) on the P face and 638 ± 109 IMP/μm(2) on the E face.

A scanning electron microscope study of the colon of the mouse (Mus musculus) infected with Eimeria ferrisi (Protozoa, Apicomplexa, Coccidia).

Micromorphological changes in the colon of mice infected with Eimeria ferrisi were studied by scanning electron microscopy. The damage observed consisted of swelling of epithelial cells, profound stretching of the host cell membranes, loss of microvilli and erosion of tissues. Mature meronts were visible at 3 days post-inoculation (PI) in localized areas of cellular rupturing.

Light and electron microscope study of Sarcocystis sp. from the fallow deer (Cervus dama).

By means of light and electron microscopy a study was made of Sarcocystis sp. from 11 fallow deer (Cervus dama). Cysts of Sarcocystis sp.

Cellular pathology in mouse embryonic brain cells following in vitro penetration by sporozoites of Eimeria papillata.

The pathology that occurs in mouse embryonic brain ( MEB ) cells that have been penetrated by sporozoites of Eimeria papillata was studied by light and electron microscopy. At the light microscopy level the greatest number of intracellular parasites was seen at 15 and 45 min postinoculation (PI). The monolayer of MEB cells had begun to round up by 45 min PI, and by 60 min PI most of the cells were stripped from the coverslip.

Ultrastructure of Sarcocystis sp. from the muscle of a white-tailed deer (Odocoileus virginianus).

Sarcocystis sp. from the muscle of naturally infected white-tailed deer (Odocoileus virginianus) was examined by transmission electron microscopy. The primary cyst wall forms regularly spaced protrusions filled with electron-lucent ground substance; no fibrils are present in the protrusions.

Fine structure of the oocyst wall and excystation of Eimeria procyonis from the American raccoon (Procyon lotor).

Oocysts of Eimeria procyonis, from the American raccoon (procyon lotor), were broken, added to a cell suspension, fixed in Karnovsky's fluid, and studied with the electron microscope. The oocyst wall has three layers: a thin electron-dense inner layer (8-15 nm), an electron-lucent middle layer (25-35 nm), and a thick outer layer (120-140 nm). The outer layer has an electron-dense inner portion and an electron-lucent outer portion that contains membrane-bound vesicles.

Ultastructural studies of Sarcocystis sp. from the camel (Camelus dromedarius) in Egypt.

By means of electron microscopy a study has been made on Sarcocystis from 29 camels (Camelus dromedarius) in Egypt. In oesophagus and diaphragm muscles sarcocysts have been observed. The micromorphology of metrocytes, merozoites as well as of the cyst wall has been described.

Clinical and histologic observations of actively induced resistance to Eimeria ferrisi Levine and Ivens, 1965 (Protozoa: Eimeriidae) in the mouse (Mus musculus).

Actively induced resistance to Eimeria ferrisi was studied clinically and histologically in Mus musculus. Results indicated that a partial resistance to challenge was obtained. Initially infected animals had severe symptoms of coccidiosis but the symptoms diminished as the infections progressed.

The endogenous stages of Eimeria utahensis (Protozoa: Eimeriidae) in the kangaroo rat, Dipodomys ordii.

The endogenous life cycle of Eimeria utahensis is described from experimentally infected kangaroo rats, Dipodomys ordii. The endogenous asexual cycle consisted of 4 generations of meronts. First-generation meronts were concentrated in the anterior third of the small intestine.

Eimeria zapi sp. n. from the meadow jumping mouse, Zapus hudsonius Zimmerman in southwestern Michigan.

Four of 5 meadow jumping mice (Zapus hudsonius) captured had in their feces a previously undescribed species of Eimeria which is named Eimeria zapi sp. n. The sporulated oocysts measured 21.

Fine structure of microgametogenesis of Eimeria ferrisi Levine and Ivens 1965 in Mus musculus.

The microgamogony of Eimeria ferrisi from experimentally infected mice was investigated with the electron microscope. Microgamonts were recognizable by the presence of peripherally arranged nuclei and the presence of single or paired centrioles between each nucleus and the limiting membrane of the parasite. Often an intranuclear centrocone directed toward the centriole was present.

Ultrastructure of macrogametogenesis of Eimeria mivati.

The development of the macrogamete of Eimeria mivati Edgar and Seibold 1964 was studied with the electron microscope. Development of the young gamont was characterized by a loss of organelles such as the apical complex, subpellicular microtubules, rhoptries and micronemes, followed by an increase in micropores, mitochondria, rough endoplasmic reticulum (rER), and Golgi complexes. Nuclear detachment bodies and canaliculi were present in maturing macrogamonts.