Eimeria spp. of Domestic Fowl: The Migration of Sporozoites Intra- and Extra-Enterically

Abstract

Chickens were dosed orally with sporulated oocysts of Eimeria acervulina, E. brunetti, E. maxima, or E. praecox and the subsequent presence, in various tissues, of parasites capable of inducing patent infections was detected by transferring the tissues to coccidia-free recipients. Similar results were obtained with each of the 4 species studied, irrespective of whether initial development occurs in the superficial (E. praecox, E. brunetti) or crypt (E. acervulina, E. maxima) epithelium. Infection was transferable by gut scrapings and liver homogenates at all time intervals (3, 6, 12, 18, 24, and 36 hr postinoculation) studied. Infection was also transferable with blood and with splenic homogenates but not consistently. Transfers made within a short time of the inoculation of donors were more successful in producing patent infections in the recipients. In all transfers the prepatent period was normal for the species. These findings suggest that sporozoites enter the mucosa very shortly after inoculation, and some of them pass to the liver and spleen and then leave these tissues at a somewhat slower rate, possibly to reenter the mucosa. Sporozoites in the lamina propria of the gut were found within host mononuclear cells in all 4 species studied. Most of the cells harbouring E. maxima and some of those with E. praecox were identified as intraepithelial lymphocytes while all others could only be identified as agranular mononuclear cells that were not characteristically macrophages.

Coccidia of rabbit: a review

“…Fernando et al (1987) observed similar migration in other species of chicken coccidia, irrespective whether their initial development occurs in the crypts (E. acervulina and E. maxima) or in superficial epithelium (E. praecox and E. bruneti).…”

Goussia hyperolisi n. sp.:a coccidian infection in reed frog Hyperolis viridiflavus tadpoles which expires towards metamorphosis

“…T h s is suggested from their elongate nuclei and the processes extending from their surface, which is often disengaged from the neighboring cells. Intraepithelial lymphocytes (IELs) have been shown to be the host cells of invading sporozoites and possibly other stages as well (Lawn & Rose 1982, Fernando et al 1987, Vilenkin & Paperna 1997. The infected host cells in the tadpole gut seemed to become surrounded by additional intraepithelial leukocytes.…”

Coccidia: A review of recent advances on immunity and vaccine development

“…Inhibition may involve specific antibodies in the mucosa of immune birds which act by directly blocking invasion or by enhancing intraluminal destruction of sporozoites. However, E. tenella has been observed capping and shedding immune complexes (Speer et al, 1985b), and sporozoites taken from the caeca of immune birds develop normally when transferred to naive chickens (Rose, 1987). Conversely, E. acervulina immune birds had 11% more intracellular sporozoites (Augustine & Danforth, 1986) than controls, but they do not develop indicating that immunity interferes with further development, not simply invasion.…”

“…Site-specificity of coccidia suggest that sporozoites from different species may recognize different host cell structures during invasion. Shortly following infection, sporozoites can be seen invading cells of the intestinal (or caecal) surface epithelium (Van Doornick & Becker, 1956;Rose, 1987), and development of some species occurs here (E. brunetti and E. praecox). Other species develop in endothelial cells of villi lacteals (E. bovis), the lamina propria (E. zuernii) or the epithelium of the crypts (E. acervulina, E. maxima, E. necatrix, E. tenella, E. falciformis, E. vermiformis).…”

“…This review attempts to summarize recent studies on host immunity and vaccine development to coccidia. For more detailed information, the reader is referred to previous reviews on immunity (Rose, 1987;Lillehoj, 1991) and recombinant coccidial antigens (Ellis & Tomley, 1991).…”