Coprological examinations of three snowy owls, Nyctea scandiaca (L.) revealed the presence of a coecidium of the genus Eimeria that apparently represents a previously undescribcd species. Oocysts of Eimeria nycteae sp. n. were spherical to subspherical, 23.6 (23-25) x 22.2 (22-23) pm with a shape index 1.1 (1.0-1.1). The oocyst wall was bilayered, smooth - 0.75 pin thick. A polar granule was absent. Sporocysts were ellipsoidal, 18.5 (18-19) x 9.8 (9-10) pm with a shape index 1.9 (1.8-2.1) with Stieda and substieda bodies. A sporocyst residuum was present as small granules scattered among sporozoitcs. The sequence of the sporulation process of this new species is given and illustrated with photomicrographs. Owls examined did not exhibit any signs of alteration of their health status.
Six young tortoises Testudo marginata Schoepff, 1792 were experimentally infected with Hemolivia mauritanica (Sergent et Sergent, 1904). The prepatent period ranged from 6 to 8 weeks. Young, smaller, club-like forms (6-9 × 3-6 µm) of gametocytes appeared in the peripheral blood first, whereas mature, elongated, cylindrical forms (9-12 × 5-7 µm) were detected after 1-2 weeks and predominated during later patency. Three of the infected tortoises were euthanized and dissected to study the endogenous stages. Meronts occurred in the cells of the reticulo-endothelial system and in the erythrocytes; these were observed mostly in parenchymatous organs. Mature forms measured 14.2 × 9.3 µm and contained 7-12 merozoites. Cysts with two (exceptionally one) cystozoites were also found predominantly in parenchymatous organs and measured 14.8 × 7.9 µm. Pathological changes attributable to Hemolivia were mild and limited to liver and kidneys. The role of individual developmental stages of haemogregarines is discussed with respect to evolution of heteroxenous life cycle and long-term persistence of parasites in their intermediate hosts.
An ICR outbred suckling mouse model of cryptosporidiosis was used to explain some of the variability associated with experimental Cryptosporidium parvum infections in neonate mice. Fourty four groups of 12 mice each, ranging in age from 4-12 days, each received 1.0 x 104 CsCl purified oocysts per os in 5 pm PBS. At 6 days post-inoculation (PI), mice were killed by C02 overdose and individually weighed. Intestines were then homogenized and oocysts were quantified by hemacytometer. Results revealed that both age and weight have pronounced effects on numbers of oocysts produced in vivo, with larger and older mice producing higher numbers of parasites. Mice 8-9 days of age at the time of inoculation displayed the least amount of weight dependent variability, produced the highest numbers of oocysts, and were judged to be superior over other ages for pharmaceutical screening. Significant reductions in numbers of oocysts occurred in mice inoculated at 10 days of age, and only a few oocysts were found in mice inoculated at 11-12 days of age. These studies suggest that at least some data on Cryptosporidium generated from suckling mouse studies to date are probably unreliable and should be viewed skeptically.
The genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) is composed of intracellular haemogregarine parasites that are widely distributed among all tetrapod groups. The present study combines microscopic and molecular data on haemogregarine parasites from lizards in the western Mediterranean. We screened tissue samples and examined blood smears for the presence of species of Hepatozoon from four lizards, namely Algyroides marchi Valverde, endemic to Southeast Spain, Podarcis bocagei Seoane from Spain and Portugal, P. hispanica Steindachner from Spain, and P. lilfordi Günther from Cabrera, Balearic Islands (Spain). Our results show that prevalence and intensity of Hepatozoon parasites vary between and within lizard species from different regions. Algyroides marchi and P. bocagei from Spain had the lowest values, whereas P. hispanica had the highest. Phylogeny based on 18S rRNA gene sequences indicates that most of the new Hepatozoon sequences are part of a clade exclusive from North African and Iberian lizards, except for a single P. bocagei isolate that is found related to another clade including isolates from other reptile host species and rodents. Interestingly, isolates from Algyroides form a distinct monophyletic subgroup, which could be a signal of strict host-specificity within this host genus.
Six new species of coccidia are described from endangered Phelsuma spp. geckoes (Sauria: Gekkonidae) endemic to Mauritius, Indian Ocean. Five new species (3 Eimeria and 2 Isospora species) are described from Phelsuma rosagularis Vinson et Vinson; all lack a micropyle and an oocyst residuum, and all have a sporocyst residuum. Oocysts of Eimeria swinnertonae sp. n. are ellipsoidal, 22.2 × 17.8 (20.8-24.8 × 16.8-18.4) μm; SI 1.25; polar granule absent. Sporocysts are ellipsoidal, 8.8 × 7.0 (8.0-9.6 × 6.4-8.0) μm; SI 1.3; Stieda body absent. Oocysts of Eimeria stebbinsi sp. n. are ellipsoidal, 17.4 × 11.7 (16.0-19.2 × 11.2-12.8) μm; SI 1.5; polar granules present. Sporocysts are elongate-ellipsoidal, 7.7 × 4.0 (7.2-8.0 × 3.2-5.6) μm; SI 1.9; Stieda body present. Oocysts of Eimeria raleighi sp. n. are spheroidal to sub-spheroidal, 17.0 × 15.5 (16.0-19.2 × 14.4-16.8) μm; SI 1.1; polar granule present. Sporocysts are sub-spheroidal, 7.8 × 6.6 (7.2-8.0 × 6.4-7.2) μm; SI 1.2; Stieda body absent. Oocysts of Isospora cottinghamae sp. n. are ellipsoidal, 19.8 × 15.5 (17.6-21.6 × 14.4-17.6) μm; SI 1.3; polar granules present. Sporocysts are ellipsoidal, 10.8 × 6.9 (9.6-12.8 × 6.4-8.0) μm; SI 1.6; Stieda body present. Oocysts of Isospora pearlae sp. n. are ellipsoidal, 16.0 × 11.5 (15.2-17.6 × 9.6-12.8) μm; SI 1.4; polar granule present. Sporocysts are ellipsoidal, 8.8 × 5.4 (8.0-9.6 × 4.8-6.4) μm; SI 1.6; Stieda and substieda bodies present. One new Eimeria species is described from the blue-tailed day gecko, Phelsuma cepediana Merrem. Oocysts of Eimeria hartleyi sp. n. are sub-spheroidal to ellipsoidal, 18.2 × 14.5 (16.0-20.8 × 13.6-16.0) μm; SI 1.26; polar granules present. Sporocysts are ellipsoidal to cylindroidal, 7.5 × 5.3 (6.4-8.0 × 4.8-6.4) μm; SI 1.4; Stieda body present. We report the presence of tetrazoic spheroidal to sub-spheroidal oocysts or sporocysts 10.2 × 8.5 (9.9-10.4 × 8.3-8.8) μm; SI 1.2 from an individual of P. cepediana. These oocysts or sporocysts are significantly larger than the Cryptosporidium species so far described from reptiles, and likely represent excretion of spuriously ingested sporocysts of a Sarcocystis or Adelina coccidian.
Toxoplasma gondii Nicolle et Manceaux, 1908 is an apicomplexan parasite with a worldwide distribution. It is of great medical and veterinary importance because it may cause abortion or congenital disease in its intermediate hosts, including man. The European bison, the largest herbivorous animal in Europe, is a species that has been saved from extinction. Twenty-four of 95 examined sera of the European bison (Bison bonasus bonasus) from the Białowieża Forest, Poland collected from 2008 to 2011 were found to be positive for the presence of T. gondii-specific IgG antibodies using a direct agglutination test, with the antibody titre in positive animals ranging from 40 to 18000. Statistically significant differences were observed only between years of sample collection. This is the first report on T. gondii in lowland European bison living in the natural environment.
Trafficking of the rhoptry chimeric protein RhopH2-GFP, which contains RhopH2 signal peptide plus the downstream five amino acids, was dissected by treating parasites with Brefeldin A at three different time points. Twenty eight hrs-stage trophozoites accumulated the chimera within the parasite endoplasmic reticulum. In 32 hrs-stage schizonts, the chimera was distributed in the parasite cytoplasm but not in the parasitophorous vacuole. In 36 hrs stage-schizonts, the chimera was detected in the individual parasitophorous vacuoles of the developing merozoites and, in contrary to non-treated parasites, no immature rhoptry vesicles could be detected in the cytoplasm of immature merozoites. These data show that this chimera is trafficked to the rhoptries via Brefeldin A-sensitive pathway indicating that this trafficking is similar to that of the endogenous rhoptry proteins, and that the five amino acids downstream of the signal peptide cleavage site may contain the sorting signal required for rhoptry targeting.
Coprological examination of New Caledonian geckoes of the genus Rhacodactylus Fitzinger, 1843 revealed two new species of coccidia. Isospora leachiani sp. n. from R. leachianus (Cuvier, 1829) has oval, colourless oocysts, measuring 21-26 × 16-18.5 µm. Sporocysts are ellipsoidal, 11-12.5 × 6.5-8 µm, with distinct Stieda and substieda bodies. Oocysts of Isospora sykorai sp. n. from R. ciliatus (Guichenot, 1866) are elongately oval to cylindrical, 20-23.5 × 11-14 µm; sporocysts of this species are ellipsoidal, 10-11.5 × 7-8 µm, with a slightly pointed end and Stieda and substieda bodies. Infected geckoes did not exhibit any alteration of their health status.