The Invasion of the Cecal Mucosa by Eimeria tenella sporozoites and their Transport by Macrophages*

SYNOPSIS. Sporozoites of Eimeria tenella were injected into the peritoneal cavity of normal chickens and chickens immunized against E. tenella. In some experiments normal scrum and serum from resistant chickens were injected prior to the injection of sporozoites. After 15 or 30 minute periods of intraperitoneal incubation, exudates were harvested and the occurrence of intracellular sporozoites was determined. Only macrophages and degranulated granulocytes were observed to contain sporozoites. There was no significant difference between the number of macrophages obtained from normal chickens (normal macrophages) which contained sporozoites and the number of macrophages obtained from immune chickens (immune macrophages) which contained sporozoites. Significantly fewer immune macrophages treated with immune serum contained sporozoites than untreated normal or immune cells, normal macrophages treated with either serum, or immune macrophages treated with normal scrum. Sporozoites in untreated normal macrophages did not appear to be harmed by the intracellular environment, based on structural observations. The majority of sporozoites in macrophages from all other groups were difficult to distinguish within the cytoplasm and were visibly distorted. It is hypothesized that the presence of fewer infected macrophages in exudates of immune chickens and serum‐treated normal chickens was caused by an enhanced ability of these cells to destroy the parasite. Similar observations were noted in the case of sporozoites within degranulated granulocytes of experimental groups. The lack of understanding of the degranulation phenomenon makes it difficult to interpret these findings.

mentioning

confidence: 99%

Cellular Aspects of the Resistance of Chickens to Eimeria tenella Infections*

Huff

Clark

1970

“…Is it one that enters the glandular epithelium from the gland lumen, or is it one that passes through the lamina propria? Challey and Burns (2) and Van Doorninck and Becker(l3) supported the view that the cycles of E . tenella and E .…”

Section: Discussionmentioning

confidence: 87%

“…However, there are several differences concerning the speed with which sporozoites were transported to the gland and whether they were free or associated with a macrophage. Challey and Burns (2) found no E . tenella sporozoites in the lamina propria at 48 hr and Pattillo(l0) found none there at 38 and 54 hr.…”

Section: Discussionmentioning

confidence: 96%

“…necatrix found that sporozoites pass through the lamina propria to the gland of Lieberkuhn where they develop. Cells within the lamina propria, assumed to be macrophages, have been mentioned as transporters of sporozoites ( 2,13). Van Doorninck and Becker( 13) thought that transport of sporozoites by macrophages may be an attempt by the host to excrete the parasite.Tyzzer (l1) found no developmental stages of E .…”

mentioning

confidence: 99%

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The Migration of Eimeria acervulina Sporozoites to the Duodenal Glands of Lieberkühn

Doran

1966

SYNOPSIS. The establishment of Eimeria acervulina sporozoites in the duodenal glands of Lieberkühn of the chicken is described. Sporozoites were found to enter the tips of the villi and pass into the lamina propria, or core, of the villus. Within the lamina propria, sporozoites were engulfed by macrophages and taken to the glandular epithelium. Data are presented which indicate that macrophages serve as a defense against infection as well as a mode of transportation.

“…The finding of sporozoites in intraepithelial leukocytes (IEL) deep in the crypts of Lieberkiihn indicate that E. mitis uses transport host cells to reach the crypts as do E. tenella, E. necatrix, and E. acervulina (2,3,10,18,22). No development like that of E. dispersa in the turkey (1 5) occurred in IEL's with E .…”

Section: Discussionmentioning

confidence: 99%

A Redescription of the Life Cycle of Eimeria mitis Tyzzer, 1929

Novilla

Jeffers

Griffing

et al. 1987

Ten-day-old broiler chickens were inoculated with oocysts of a characterized strain of Eimeria mitis, and tissues were fixed at 4, 8, or 24-h intervals after inoculation for histopathological examination. Tissue collections were initiated at the time of inoculation and extended up to 168 h postinoculation. The preferred site of development of E. mitis was found to be the ileum although more limited development of the parasite also took in the jejunum, cecal pouches, cloaca, and bursa of Fabricius. No distinctive and consistent intestinal lesions were macroscopically evident even in heavily parasitized chickens. The prepatent period was approximately 92 h postinoculation. The histopathological features of the E. mitis infections were characterized using conventional bright-field microscopy as well as both scanning and transmission electron microscopy. No extra-intestinal development of the parasite was observed.