Eimeria Papillata Research Articles

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. The number of infections required to elicit a protective immune response was also determined for each coccidial species in BALB/c mice. We report the first description of patent infections in inbred immunocompetent and immunodeficient mice infected with E. papillata. Results indicate that during primary infections, parasite replication is under partial immunological control for all Eimeria species. However, the control is mechanistically different for E. papillata because the adaptive immune response does not contribute to the control of primary infections. Both coccidial species infecting intestinal villar epithelial cells (E. papillata and E. ferrisi) were affected by the beige mutation using parasite output as an indicator, whereas E. falciformis, which infects intestinal crypt cells, is not. BALB/c mice were more resistant to challenge infections with upper intestinal parasites (E. papillata and E. vermiformis) in comparison to challenge infections with lower intestinal and cecal parasites (E. falciformis and E. ferrisi).

Specificity and cross-reactivity of hybridoma antibodies generated against Eimeria bovis sporozoites

Specificity and cross-reactivity of hybridoma antibodies generated against Eimeria bovis sporozoites

Evolutionary relationships among Eimeria spp. (Apicomplexa) infecting cricetid rodents

Evolutionary relationships among seven species of Eimeria from five species of cricetid rodents (Neotoma albigula, Peromyscus eremicus, Peromyscus leucopus, Peromyscus maniculatus, Peromyscus truei) were examined by phenetic and cladistic analysis of oocyst structure, life-history data, and isozyme banding patterns. Phenetic and cladistic analyses revealed two distinct lineages of Eimeria spp.: type A Eimeria spp. (Eimeria albigulae, Eimeria arizonensis, Eimeria peromysci), characterized by subspheroid oocysts with rough outer walls, lemon-shaped sporocysts, oocyst residua, prominent Stieda bodies, and two obvious wall layers; and type B Eimeria spp. (Eimeria delicata, Eimeria lachrymalis, Eimeria ladronensis, Eimeria lange-barteli), characterized by ellipsoid oocysts with one obvious, smooth wall, no residuum, and ellipsoid or teardrop-shaped sporocysts with thin walls and tiny Stieda bodies. Cladistic analysis of the type A and type B data sets, using Eimeria nieschulzi and Eimeria papillata (hosts: Rattus norvegicus and Mus musculus, respectively) for outgroup comparison, showed the more derived nature of Eimeria spp. infecting Peromyscus spp. relative to those species infecting N. albigula. Comparison of parasite phylogenies to a hypothesized phylogeny for the hosts based on enzyme electrophoretic data revealed patterns of host–parasite phylogenetic congruence that were most evident at the generic level of the hosts.