The Occurrence of a Second Asexual Generation in the Life Cycle of Eimeria bovis in Calves

Hammond, Datus M.; Andersen, Ferron L.; Miner, Merthyr L.

doi:10.2307/3275812

Cited by 23 publications

(9 citation statements)

References 5 publications

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“…in endothelial cells of the central lacteals in the villi of the distal ileum, reaching a size of up to 300 lm and containing more than 120,000 merozoites (Hammond et al 1964). Second stage schizonts, which contain only 36 merozoites, and gamonts develop in epithelial cells of the caecum (Hammond et al 1963). Particularly the ®rst generation schizonts of E. bovis are of interest in various aspects.…”

Section: Introductionmentioning

confidence: 99%

Development of Eimeria bovis in vitro: suitability of several bovine, human and porcine endothelial cell lines, bovine fetal gastrointestinal, Madin–Darby bovine kidney (MDBK) and African green monkey kidney (VERO) cells

et al. 2001

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Several bovine, human and porcine endothelial cell lines, bovine fetal gastrointestinal cells (BFGC), Madin-Darby bovine kidney (MDBK) and African green monkey kidney (VERO) cells were exposed in vitro to sporozoites of Eimeria bovis. Parasites invaded all cells used and changed their shape to more stumpy forms within 12 h. Sporozoites left their host cells and invaded new ones frequently within the first 12 h post-infection. Further development took place only in bovine cells, although parasites survived in the other cells for at least 3 weeks. Within the non-bovine cells, conspicuously enlarged parasitophorous vacuoles developed in VERO cells and reached a diameter of 15-20 microm. The best development to first generation schizonts with regard both to time required to mature, to schizont size and to merozoite yields was observed in BFGC, followed by bovine umbilical vein and bovine spleen lymphatic endothelial cells. MDBK cells were less suitable. The life cycle was completed (development of oocysts) only occasionally in BFGC. Results are considered under several aspects. Thus, infected VERO cells may represent a suitable tool for studying the parasitophorous vacuole, while infected endothelial cells represent a system quite narrow to the in vivo situation and should allow basic studies on parasite/host cell interactions and BFGC can be used for the mass production of E. bovis first generation merozoites.

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Section: Introductionmentioning

confidence: 99%

Development of Eimeria bovis in vitro: suitability of several bovine, human and porcine endothelial cell lines, bovine fetal gastrointestinal, Madin–Darby bovine kidney (MDBK) and African green monkey kidney (VERO) cells

et al. 2001

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“…In each of the immunized calves, oocysts retained from the immunizing inoculations were found in the lamina propria of the mucosa, as previously described (Hammond et al, 1963a). In the first experiment the interval between the peak oocyst discharge of the immunizing infection and the first biopsy was 20 days, suggesting that the oocysts had been held in the tissues approximately that long.…”

Section: Methodsmentioning

confidence: 91%

Response of Immunized and Nonimmunized Calves to Cecal Inoculation of First-Generation Merozoites of Eimeria bovis

Hammond¹,

Andersen²,

Miner³

1964

The Journal of Parasitology

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“…In vivo, E. bovis merozoites I selectively invade and replicate within host epithelial cells of the large intestine, namely crypt epithelial cells of the cecum/colon (Hammond et al 1963(Hammond et al , 1964). In the current study, we successfully established a suitable in vitro culture system for E. bovis merozoite I infection, resulting in the formation of meronts II and the release of viable merozoites II.…”

Section: Discussionmentioning

confidence: 99%

“…Instead of infecting enterocytes like other Eimeria species in cattle, free E. bovis sporozoites must invade endothelial cells of the central lymph capillaries of the villi of the ileum to develop into large first-generation macromeronts reaching sizes of 250-300 μm within a period of 14-18 days in vivo (Hammond et al 1963;Hammond et al 1964, Hammond andFayer 1967). After endothelial host cell rupture, mature macromeronts of E. bovis release more than 140,000 merozoites I, which then have to migrate to the large intestine in order to infect colonic epithelial host cells in the crypts and to develop into second-generation meronts (meronts II).…”

Section: Introductionmentioning

confidence: 96%

“…After endothelial host cell rupture, mature macromeronts of E. bovis release more than 140,000 merozoites I, which then have to migrate to the large intestine in order to infect colonic epithelial host cells in the crypts and to develop into second-generation meronts (meronts II). In vivo meronts II are much smaller in size than meronts I and produce only 30-36 merozoites II after maturation (Hammond et al 1963(Hammond et al , 1964. Free-released merozoites II as well as gamonts (macro-and microgamonts) then develop in epithelial cells of the cecal and colonic crypts (Hammond et al 1964).…”

Section: Introductionmentioning

confidence: 97%

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Suitable in vitro culture of Eimeria bovis meront II stages in bovine colonic epithelial cells and parasite-induced upregulation of CXCL10 and GM-CSF gene transcription

et al. 2015

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We here established a suitable in vitro cell culture system based on bovine colonic epithelial cells (BCEC) for the development of Eimeria bovis merozoites I and the characterization of early parasite-induced innate epithelial host cell reactions as gene transcription of proinflammatory molecules. Both primary and permanent BCEC (BCEC (rim) and BCEC(perm)) were suitable for E. bovis merozoite I invasion and subsequent development of meronts II leading to the release of viable merozoites II. E. bovis merozoite II failed to develop any further neither into gamont nor oocyst stages in BCEC in vitro. E. bovis merozoite I induced innate epithelial host cell reactions at the level of CXC/CCL chemokines (CXCL1, CXCL8, CXCL10, CCL2), IL-6, and GM-CSF gene transcription. Overall, both BCEC types were activated by merozoite I infections since they showed significantly enhanced gene transcript levels of the immunomodulatory molecules CXCL10 and GM-CSF. However, gene transcription profiles of BCEC(prim) and BCEC(perm) revealed different reaction patterns in response to merozoite I infection with regard to quality and kinetics of chemokine/cytokine gene transcription. Although both BCEC types equally showed most prominent responses for CXCL10 and GM-CSF, the induction of CXCL1, CXCL8, CCL2, and IL-6 gene transcripts varied qualitatively and quantitatively. Our results demonstrate that BCEC seem capable to respond to E. bovis merozoite I infection by the upregulation of CXCL10 and GM-CSF gene transcription and therefore probably contribute to host innate effector mechanisms against E. bovis.

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The Occurrence of a Second Asexual Generation in the Life Cycle of Eimeria bovis in Calves

Cited by 23 publications

References 5 publications

Development of Eimeria bovis in vitro: suitability of several bovine, human and porcine endothelial cell lines, bovine fetal gastrointestinal, Madin–Darby bovine kidney (MDBK) and African green monkey kidney (VERO) cells

Development of Eimeria bovis in vitro: suitability of several bovine, human and porcine endothelial cell lines, bovine fetal gastrointestinal, Madin–Darby bovine kidney (MDBK) and African green monkey kidney (VERO) cells

Response of Immunized and Nonimmunized Calves to Cecal Inoculation of First-Generation Merozoites of Eimeria bovis

Suitable in vitro culture of Eimeria bovis meront II stages in bovine colonic epithelial cells and parasite-induced upregulation of CXCL10 and GM-CSF gene transcription

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