Transport of Eimeria necatrix Sporozoites in the Chicken: Effects of Irritants Injected Intraperitoneally

Abstract

Light and electron microscopic observations confirmed that Eimeria necatrix sporozoites first enter villous epithelial cells of the chicken small intestine and are transported to the crypts by mononuclear cells. Ultrastructurally, these cells resemble granulated intraepithelial lymphocytes (IEL) rather than macrophages, as suggested previously. The injection of chickens intraperitoneally (i.p.) with a variety of irritants, including proteose peptone, at the time of oocyst inoculation or up to 12 hr postinoculation (PI) resulted in a delay in the arrival of sporozoites at the crypt. Significantly fewer sporozoites had arrived at the crypt by 24 hr PI in i.p.-injected birds as compared to controls. This delay in the arrival of sporozoites at the crypts was reflected by a delay in the development of intestinal lesions and in peak oocyst production. However, there was no significant decrease in the total numbers of oocysts produced by these birds as compared to controls, indicating that no significant loss of sporozoites occurs during the possible rerouting of the parasites. The presence of infective stages in extraintestinal sites was detected by transferring various tissues to coccidia-free recipients. Infection was transferable by gut, liver, and spleen from irritant-injected and control birds at all time intervals studied (12, 24, 36, and 48 hr PI). Infection was also transferable with blood and kidney, but not consistently. A small number of oocysts was passed by the recipients of peritoneal wash from irritant-injected birds at 12 hr PI. In all transfers, the prepatent period was normal, suggesting that the migrant stages are sporozoites.

Coccidia of rabbit: a review

“…Perhaps it is an inheritance from an unknown ancestor with more complex life cycle or such traffic is important for the parasite to find its specific site of development. As mentioned above, sporozoites of chicken coccidia also migrate in the host mucosa and there is even evidence of their extra intestinal localisation (Long and Millard 1979, Kogut and Long 1984, Al-Attar and Fernando 1987. Patent infection appeared in coccidia-free recipients after infection with blood and homogenates from liver, spleen and other organs of infected donors.…”

Recent Advances in Biology and Immunobiology ofEimeriaSpecies and in Diagnosis and Control of Infection with These Coccidian Parasites of Poultry

“…Sporozoites of some species (E. brunetti and E. praecox) develop within cells at the site of penetration. Sporozoites of other species (E. acervulina, E. maxima, E. necatrix, and E. tenella) are transported (1,49,95,97) to other sites, for example the crypt epithelium, where they undergo development. Within the host cells, sporozoites undergo asexual reproduction (schizogony or merogony) in which nuclear division is followed by cytoplasmic differentiation, resulting in merozoites that break free and penetrate other host cells.…”

“…There they appear to be invaded by sporozoites. It is thought that these are the cells that transport sporozoites (1,49,95,97) through the lamina propria to the crypt epithelium, where they exit and invade the crypt cells. Populations of CD8 ϩ cells also increase in the mucosa following challenge infection, where they frequently can be seen in close contact with infected cells.…”

Detection of proteins and nucleic acids of Newcastle disease virus inEimeria acervulina

“…The cytoplasm is the site for viral transcription and genome replication, as well as for viral protein synthesis and processing (Alexander, 1991). Both NDV and coccidia can infect epithelial cells of the intestine (Al-attar & Fernando, 1976;Alexander, 1991). The purpose of this study was to study the interaction of NDV and Eimeria acervulina in chickens inoculated simultaneously with E. acervulina and NDV.…”

“…To initiate infection, sporozoites are released from sporulated oocysts and invade epithelial cells lining the intestine. The entire life cycle occurs in the mucosa and lamina propria of a speci® c region of the intestine (Al-attar & Fernando, 1976). Although mild infection is often subclinical, severe infection can result in weight loss, growth depression, and even lead to death (Long & Jeffers, 1986).…”