• MeSH
• Antigens, Protozoan chemistry   genetics   metabolism   MeSH
• Apicomplexa immunology   physiology   MeSH
• Apicoplasts immunology   physiology   MeSH
• Adaptation, Biological MeSH
• Biological Evolution MeSH
• Species Specificity MeSH
• Extracellular Space immunology   metabolism   parasitology   MeSH
• Host-Parasite Interactions * MeSH
• Humans MeSH
• Membrane Proteins chemistry   genetics   metabolism   MeSH
• Protozoan Infections, Animal immunology   metabolism   parasitology   MeSH
• Protozoan Infections immunology   metabolism   parasitology   MeSH
• Protozoan Proteins chemistry   genetics   metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Antigens, Protozoan MeSH
• Membrane Proteins MeSH
• Protozoan Proteins MeSH

This study focused on the attachment strategy, cell structure and the host-parasite interactions of the protococcidian Eleutheroschizon duboscqi, parasitising the polychaete Scoloplos armiger. The attached trophozoites and gamonts of E. duboscqi were detected at different development stages. The parasite develops epicellularly, covered by a host cell-derived, two-membrane parasitophorous sac forming a caudal tipped appendage. Staining with Evans blue suggests that this tail is protein-rich, supported by the presence of a fibrous substance in this area. Despite the ultrastructural evidence for long filaments in the tail, it stained only weakly for F-actin, while spectrin seemed to accumulate in this area. The attachment apparatus consists of lobes arranged in one (trophozoites) or two (gamonts) circles, crowned by a ring of filamentous fascicles. During trophozoite maturation, the internal space between the parasitophorous sac and parasite turns translucent, the parasite trilaminar pellicle seems to reorganise and is covered by a dense fibrous glycocalyx. The parasite surface is organised in broad folds with grooves in between. Micropores are situated at the bottom of the grooves. A layer of filaments organised in bands, underlying the folds and ending above the attachment fascicles, was detected just beneath the pellicle. Confocal microscopy, along with the application of cytoskeletal drugs (jasplakinolide, cytochalasin D, oryzalin) confirmed the presence of actin and tubulin polymerised forms in both the parasitophorous sac and the parasite, while myosin labelling was restricted to the sac. Despite positive tubulin labelling, no microtubules were detected in mature stages. The attachment strategy of E. duboscqi shares features with that of cryptosporidia and gregarines, i.e. the parasite itself conspicuously resembles an epicellularly located gregarine, while the parasitophorous sac develops in a similar manner to that in cryptosporidia. This study provides a re-evaluation of epicellular development in other apicomplexans and directly compares their niche with that of E. duboscqi.

• MeSH
• Actins ultrastructure   MeSH
• Apicomplexa classification   physiology   ultrastructure   MeSH
• Host-Parasite Interactions MeSH
• Polychaeta parasitology   MeSH
• Protozoan Proteins ultrastructure   MeSH
• Trophozoites physiology   MeSH
• Tubulin ultrastructure   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Actins MeSH
• Protozoan Proteins MeSH
• Tubulin MeSH

The degree of host specificity, its phylogenetic conservativeness and origin are virtually unknown in Eimeria. This situation is largely due to the inadequate sample of eimerian molecular data available for reliable phylogenetic analyses. In this study, we extend the data set by adding 71 new sequences of coccidia infecting 16 small-mammal genera, mostly rodents. According to the respective feasibility of PCR gene amplification, the new samples are represented by one or more of the following genes: nuclear 18S rRNA, plastid ORF 470, and mitochondrial COI. Phylogenetic analyses of these sequences confirm the previous hypothesis that Eimeria, in its current morphology-based delimitation, is not a monophyletic group. Several samples of coccidia corresponding morphologically to other genera are scattered among the Eimeria lineages. More importantly, the distribution of eimerians from different hosts indicates that the clustering of eimerian species is influenced by their host specificity, but does not arise from a cophylogenetic/cospeciation process; while several clusters are specific to a particular host group, inner topologies within these clusters do not reflect host phylogeny. This observation suggests that the host specificity of Eimeria is caused by adaptive rather than cophylogenetic processes.

• MeSH
• Species Specificity MeSH
• Eimeria classification   physiology   MeSH
• Feces parasitology   MeSH
• Phylogeny * MeSH
• Adaptation, Physiological genetics   MeSH
• Rodentia parasitology   MeSH
• Host Specificity MeSH
• Host-Parasite Interactions MeSH
• Coccidiosis parasitology   veterinary   MeSH
• Rodent Diseases parasitology   MeSH
• Plastids genetics   MeSH
• DNA, Protozoan classification   genetics   MeSH
• Electron Transport Complex IV classification   genetics   MeSH
• RNA, Ribosomal, 18S classification   genetics   MeSH
• Sequence Analysis, DNA MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• DNA, Protozoan MeSH
• Electron Transport Complex IV MeSH
• RNA, Ribosomal, 18S MeSH

Coprological examination of nine African helmeted turtles Pelomedusa subrufa from Kenya revealed the presence of a new coccidium belonging to Eimeria Schneider, 1875. Oöcysts of Eimeria lokuma n. sp. are spherical to sub-spherical, 13.6 (13-14.5) x 13 (12-14) microm, lack a micropyle and a polar granule, but possess a granular oöcyst residuum. The sporocysts are elongate, oval to spindle-shaped and 8.3 (7.5-9.5) x 4.4 (4-5) microm. The Stieda body is relatively low, flat and wide, and covered with a membranous, highly flexible, scarf-like structure which protrudes from its strengthened margins. The sporozoites possess two refractile bodies. Based on the presence of a Stieda body, the described species is classified as Eimeria (sensu stricto).

• MeSH
• Eimeria classification   cytology   isolation & purification   MeSH
• Feces parasitology   MeSH
• Turtles parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Three new species of coccidia are described from Marble-throated skink Marmorosphax tricolor from New Caledonia, namely, Isospora bocagei sp. n., Acroeimeria rouxi sp. n., and Choleoeimeria sadlieri sp.n. All species differ markedly from other eimerian coccidia described from scincid hosts. Isospora marmorosphaxi develops extra-nuclearly in small intestine. A. rouxi develops epicitoplasmatically in small intestine. C. sadlieri affects the gall bladder mucosa. Generic affiliation of Eimeria-like coccidia from reptiles is discussed and all taxa (with adequate information on endogenous development available) from scincid hosts are revised and placed into genera Acroeimeria and Choleoeimeria.

• MeSH
• Species Specificity MeSH
• Host-Parasite Interactions MeSH
• Isospora classification   cytology   growth & development   MeSH
• Lizards parasitology   MeSH
• Classification MeSH
• Life Cycle Stages * MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• New Caledonia MeSH

Coprological examination of nine bush vipers Atheris chlorechis imported from Ghana revealed the presence of a new coccidian species belonging to Eimeria Schneider, 1875. Thin walled oöcysts of Eimeria atheridis n. sp. are spherical to slightly subspherical, 22.8 (19-26) x 22.5 (19-25) microm, without micropyle, polar granule and oöcyst residuum. Sporocysts are elongately ellipsoidal, 17.1 (15-19) x 7.5 (6-8) microm, with a dome like, relatively flat Stieda body. Sporozoites possess two refractile bodies and distinct transversal striation. Based on the presence of a Stieda body the species described herein clearly belongs to the Eimeria ( sensu stricto ).

• MeSH
• Eimeria ultrastructure   MeSH
• Feces MeSH
• Microscopy, Interference MeSH
• Oocysts ultrastructure   MeSH
• Viperidae parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Ghana MeSH