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Sample records for apicomplexa

  1. Efficacy of eleven antimicrobials against a gregarine parasite (Apicomplexa: Protozoa

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    Whitman Douglas W

    2007-11-01

    Full Text Available Abstract Background The Apicomplexa are a diverse group of obligate protozoan parasites infesting a wide range of invertebrate and vertebrate hosts including humans. These parasites are notoriously difficult to control and many species continue to evolve resistance to commercial antibiotics. In this study, we sought to find an effective chemotherapeutic treatment against arthropod gregarines (Apicomplexa, and to identify candidate compounds for testing against other groups of protozoan parasites. Methods We tested eleven commercial antibiotics against a gregarine parasite of Romalea microptera grasshoppers. Infected insects were fed daily, lettuce containing known amounts of specific antibiotics. On Days 15 or 20, we measured the number of gregarines remaining in the digestive tract of each grasshopper. Results Treatment with metronidazole and griseofulvin in host insects significantly reduced gregarine counts, whereas, gregarine counts of insects fed, albendazole, ampicillin, chloramphenicol, fumagillin, quinine, streptomycin, sulfadimethoxine, thiabendazole or tetracycline, were not significantly different from the controls. However, albendazole produced a strong, but non-significant reduction in gregarine count, and streptomycin exhibited a non-significant antagonistic trend. Conclusion Our results confirm that gregarine infections are difficult to control and suggest the possibility that streptomycin might aggravate gregarine infection. In addition, the insect system described here, provides a simple, inexpensive, and effective method for screening antibiotics.

  2. Comparative genomic analysis of multi-subunit tethering complexes demonstrates an ancient pan-eukaryotic complement and sculpting in Apicomplexa.

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    Christen M Klinger

    Full Text Available Apicomplexa are obligate intracellular parasites that cause tremendous disease burden world-wide. They utilize a set of specialized secretory organelles in their invasive process that require delivery of components for their biogenesis and function, yet the precise mechanisms underpinning such processes remain unclear. One set of potentially important components is the multi-subunit tethering complexes (MTCs, factors increasingly implicated in all aspects of vesicle-target interactions. Prompted by the results of previous studies indicating a loss of membrane trafficking factors in Apicomplexa, we undertook a bioinformatic analysis of MTC conservation. Building on knowledge of the ancient presence of most MTC proteins, we demonstrate the near complete retention of MTCs in the newly available genomes for Guillardiatheta and Bigelowiellanatans. The latter is a key taxonomic sampling point as a basal sister taxa to the group including Apicomplexa. We also demonstrate an ancient origin of the CORVET complex subunits Vps8 and Vps3, as well as the TRAPPII subunit Tca17. Having established that the lineage leading to Apicomplexa did at one point possess the complete eukaryotic complement of MTC components, we undertook a deeper taxonomic investigation in twelve apicomplexan genomes. We observed excellent conservation of the VpsC core of the HOPS and CORVET complexes, as well as the core TRAPP subunits, but sparse conservation of TRAPPII, COG, Dsl1, and HOPS/CORVET-specific subunits. However, those subunits that we did identify appear to be expressed with similar patterns to the fully conserved MTC proteins, suggesting that they may function as minimal complexes or with analogous partners. Strikingly, we failed to identify any subunits of the exocyst complex in all twelve apicomplexan genomes, as well as the dinoflagellate Perkinsus marinus. Overall, we demonstrate reduction of MTCs in Apicomplexa and their ancestors, consistent with modification during

  3. Isospora dromaii n. sp. (Apicomplexa, Eimeriidae) isolated from emus, Dromaius novaehollandiae (Casuariiformes, Casuariidae).

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    dos Santos Teixeira, Carina; Gallo, Samira Salim Mello; Ederli, Nicole Brand; Berto, Bruno Pereira; de Oliveira, Francisco Carlos Rodrigues

    2014-11-01

    A new species of Coccidia (Protozoa: Apicomplexa: Eimeriidae) isolated from emus, Dromaius novaehollandiae, which was observed in Brazil is described and named. Oocysts of Isospora dromaii n. sp. are subspheroidal to ovoid in shape, measure 21.6 × 19.8 μm, and have a double and smooth wall thickness of approximately 1.4 μm. In this species, micropyle, oocyst residuum, and polar granules are absent. The sporocysts are slightly ovoid in shape and measure 13.7 × 10.0 μm. Nipple-like Stieda body and prominent sub-Stieda body are present. The sporocyst residuum is composed of small dispersed granules of varying sizes. The sporozoites are characterized by an oblong refractile body and one centrally located nucleus. This is the first description of isosporid coccidia infecting birds of the family Dromaiidae. PMID:25195056

  4. Attenuated reproduction of Strombus gigas by an Apicomplexa: Emeriidae-like parasite in the digestive gland.

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    Baqueiro Cardenas, Erick; Montero, Jorge; Frenkiel, Liliane; Aldana Aranda, Dalila

    2012-07-01

    An intense and generalized sporozoan infection was detected in every population of the queen conch, Strombus gigas through the Caribbean. In this contribution we establish the relationship between occurrences of an Apicomplexa: Emeriidae-like organism and reproductive activity at San Andres archipelago, Colombia. Occurrence of the parasites was estimated counting the feeding stage Merozoites and cysts Sporozoites at 40× magnification. Nonmetric multidimensional scaling analysis (NMDS) was made to correlate the parasites stages abundance with frequency of the reproductive stages. Gametogenesis and spawning were always low coinciding with high numbers of Merozoites, a positive correlation was established between parasite abundance with reabsorption and undifferentiated stages, and negative correlation was observed between parasite abundance with maturity and spawning stages. The nonmetric multidimensional scaling (NMDS) shows that gametogenesis, maturity and spawning increase as the number of parasites decrease, factor that could be threatening reproduction of S. gigas through the Caribbean. PMID:22484565

  5. A Database of Plastid Protein Families from Red Algae and Apicomplexa and Expression Regulation of the moeB Gene

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    Zverkov, Oleg A; Seliverstov, Alexandr V.; Lyubetsky, Vassily A

    2015-01-01

    We report the database of plastid protein families from red algae, secondary and tertiary rhodophyte-derived plastids, and Apicomplexa constructed with the novel method to infer orthology. The families contain proteins with maximal sequence similarity and minimal paralogous content. The database contains 6509 protein entries, 513 families and 278 nonsingletons (from which 230 are paralog-free, and among the remaining 48, 46 contain at maximum two proteins per species, and 2 contain at maximum...

  6. Occurrence of Cryptosporidium (Apicomplexa, Cryptosporidiidae in Crotalus durissus terrificus (Serpentes, Viperidae in Brazil

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    Karasawa Andréa Satie Matsubara

    2002-01-01

    Full Text Available The objective of the present study was to investigate the prevalence of Cryptosporidium (Apicomplexa, Cryptosporidiidae in the snake Crotalus durissus terrificus (Serpentes, Viperidae. Fifty animals were evaluated for the presence of oocysts of Cryptosporidium sp. at the time of arrival and 30 and 60 days later. Intestinal washings with saline solution (1% body weight, fecal samples, and organ scrapings were collected during the study. Oocysts were concentrated by an ether-phosphate-buffered saline sedimentation technique and then separated by a density gradient centrifugation technique. Smears were made with the sediment and submitted to modified acid-fast and auramine-rhodamine staining. Cryptosporidium-positive smears were used as controls for the experimental findings. The overall prevalence of Cryptosporidium sp. oocysts was 14%. Among the positive snakes, oocysts were detected only in the intestinal washing in two specimens, only in the feces in four specimens, and in both materials at least once in one specimen. The positive snakes were predominantly from Santa Maria da Serra city State of São Paulo (57.1%. We also observed that all of the examinations that presented positive results were obtained at least 27 days after the capture of the animals.

  7. Occurrence of Apicomplexa-like structures in the digestive gland of Strombus gigas throughout the Caribbean.

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    Aranda, Dalila Aldana; Frenkiel, Liliane; Brulé, Thierry; Montero, Jorge; Cárdenas, Erick Baqueiro

    2011-02-01

    The queen conch, Strombus gigas, is a marine resource of ecological and economical importance in the Caribbean region. Given its importance in this region, and the critical status of most populations, the reproductive biology of this species has been studied to support management decisions. It was from these studies that a generalized sporozoan infection was detected. This study describes the geographic distribution of a coccidian (Apicomplexa) parasite infecting the digestive gland of S. gigas throughout the Caribbean. The parasite was present in every location sampled. Based on histological analysis, the parasites from all locations are similar and appear to complete their life cycle within the digestive gland. The highest occurrence of the parasites was registered in samples from Puerto Rico (54 parasites per field) and Martinique (45 parasites per field). The lowest incidence was registered on the Mexican coast of Yucatan peninsula, at Alacranes and Chinchorro with 17 parasites per field. Data showed significant differences among sites (Kruskal Wallis H=106.957; p ≤ 0.05). The abundance of parasites found in the digestive ducts and in the faeces suggests the liberation of parasites to the environment. A gradual decrease in abundance was found from East to West of the Caribbean sea. PMID:20851703

  8. New species of Cryptosporidium Tyzzer, 1907 (Apicomplexa) from amphibian host: morphology, biology and phylogeny.

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    Jirků, Miloslav; Valigurová, Andrea; Koudela, Bretislav; Krízek, Jaroslav; Modrý, David; Slapeta, Jan

    2008-06-01

    Cryptosporidium fragile sp. n. (Apicomplexa) is described from black-spined toads, Duttaphrynus melanostictus (Schneider) (Amphibia, Anura, Bufonidae) from the Malay Peninsula. The parasitized animals were directly imported from Malaysia and harboured C. fragile at the time of arrival. Oocysts were subspherical to elliptical with irregular contour in optical section, measuring 6.2 (5.5-7.0) x 5.5 (5.0-6.5) microm. Oocyst wall was smooth and colourless in light microscopy. The endogenous development of C. fragile in the stomach of black-spined toad was analysed in detail using light and electron microscopy. Cryptosporidian developmental stages were confined to the surface of gastric epithelial cells. In transmission experiments, C. fragile has not been infective for one fish species, four amphibian species, one species of reptile and SCID mice. Full length small subunit rRNA gene sequence was obtained. Phylogenetic reconstruction revealed distinct status of C. fragile within the clade of species with gastric localisation including Cryptosporidium muris Tyzzer, 1907, Cryptosporidium serpentis Levine, 1980 and Cryptosporidium andersoni Lindsay, Upton, Owens, Morgan, Mead et Blagburn, 2000. Described characteristics differentiate C. fragile from the currently recognized Cryptosporidium species. Our experience with the description of C. fragile has led us to revise the recommended criteria for an introduction of a new Cryptosporidium species name. C. fragile is the first species described and named from an amphibian host. Its prevalence of 83% (15/18) in black-spined toads within the 3 months after importation calls for strict quarantine measures and import regulation for lower vertebrates. PMID:18666410

  9. A new species of Eimeria (Apicomplexa: Eimeriidae) from the western hognose snake, Heterodon nasicus (Serpentes: Xenodontidae), from Texas.

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    Daszak, Peter; Ball, Stanley J; Streicker, Daniel G; Snow, Keith R

    2011-06-01

    A new species of coccidian (Apicomplexa: Eimeriidae) is described from the feces of a western hognose snake Heterodon nasicus (Serpentes: Xenodontidae) collected from Texas, and housed in the collection of the Zoological Society of London. Oocysts of Eimeria mchenryi n. sp. are cylindrical, 35.0 ± SD 1.4 (32-37) × 17.0 ± 0.7 (16-18) µm; the shape index (length/width) is 2.05. A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are subspherical 9.3 (7-11.5) × 7.7 (6-9) µm, with a shape index of 1.2. There is a sporocyst residuum, but the new species is lacking Stieda bodies. The new species is distinct from those previously named from the Xenodontidae and the allied family, Colubridae. PMID:21506855

  10. A new coccidian, Isospora rheae sp. nov. (Apicomplexa, Eimeriidae, from Rhea americana (Aves, Rheidae from South America

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    Samira S.M. Gallo

    2014-12-01

    Full Text Available A new species of coccidian (Protozoa: Apicomplexa: Eimeriidae obtained from rheas, Rhea americana, is reported in Brazil. Oocysts of Isospora rheae sp. nov. are spherical to subspheroidal, measuring 22.6 × 21.0 µm, and have a double and smooth wall that is approximately 1.7 µm thick. The micropyle, oocyst residuum and polar granule are absent. Sporocysts are slightly ovoid, measuring 13.9 × 9.6 µm. The Stieda body is flattened, the substieda body is pointed, irregular and wavy and the sporocyst residuum is composed of scattered granules of varying sizes. Sporozoites have an oblong refractile body and one nucleus. This is the first description of an isosporid coccidian infecting birds of the family Rheidae.

  11. Isospora cardellinae n. sp. (Apicomplexa: Eimeriidae) from the red warbler Cardellina rubra (Swainson) (Passeriformes: Parulidae) in Mexico.

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    Salgado-Miranda, Celene; Medina, Juan Pablo; Zepeda-Velázquez, Andrea Paloma; García-Conejo, Michele; Galindo-Sánchez, Karla Patricia; Janczur, Mariusz Krzysztof; Soriano-Vargas, Edgardo

    2016-10-01

    A new coccidian species (Protozoa: Apicomplexa: Eimeriidae) collected from the red warbler Cardellina rubra (Swainson) is reported from the Nevado de Toluca National Park, Mexico. Isospora cardellinae n. sp. has subspherical oöcysts, measuring on average 26.6 × 25.4 μm, with smooth, bi-layered wall, c.1.3 μm thick. Micropyle, oöcyst residuum, and polar granule are absent. Sporocysts are ovoidal, measuring on average 19.0 × 12.0 µm, with a knob-like Stieda body, a trapezoidal sub-Stieda body and sporocyst residuum composed of scattered spherules of different sizes. Sporozoites are vermiform with one refractile body and a nucleus. This is the fourth description of an isosporoid coccidian infecting a New World warbler. PMID:27638736

  12. Detection of antibodies against Brucella abortus, Leptospira spp., and Apicomplexa protozoa in water buffaloes in the Northeast of Argentina.

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    Konrad, José L; Campero, Lucía M; Caspe, Gastón S; Brihuega, Bibiana; Draghi, Graciela; Moore, Dadin P; Crudeli, Gustavo A; Venturini, María C; Campero, Carlos M

    2013-11-01

    Water buffalo industry has become a profitable activity worldwide, including the Northeast of Argentina (NEA). However, research on diseases affecting this species is scarce. The aim of the present study was to detect antibodies against Brucella abortus, Leptospira spp., Neospora caninum, Toxoplasma gondii, and Sarcocystis spp. in 500 water buffalo cows from five ranches (100 animals each) in the NEA. Serum samples were tested for B. abortus by fluorescence polarization assay, Leptospira spp. by microagglutination test, and N. caninum, T. gondii, and Sarcocystis spp. by indirect fluorescent antibody tests. Overall, the proportion of seropositive animals was 6.4, 22.2, 42.2, 25.4, and 50.8 % for brucellosis, leptospirosis, neosporosis, toxoplasmosis, and sarcocystosis, respectively. The proportion of seropositive animals for all diseases was statistically different among herds (p < 0.05). Statistical differences were also detected among age groups for brucellosis and neosporosis (p < 0.05). The detection of specific antibodies to B. abortus, Leptospira spp., and several Apicomplexa protozoans in water buffaloes in the NEA is reported in this study. PMID:23765549

  13. A new Apicomplexa-specific protein kinase family : multiple members in Plasmodium falciparum, all with an export signature

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    Mercereau-Puijalon Odile

    2005-03-01

    Full Text Available Abstract Background Malaria caused by protozoan parasites of the genus Plasmodium spp. is a major health burden in tropical countries. The development of new control tools, including vaccines and drugs, is urgently needed. The availability of genome sequences from several malaria parasite species provides a basis on which to identify new potential intervention targets. Database mining for orthologs to the Plasmodium falciparum trophozoite protein R45, a vaccine candidate, led us identify a new gene family. Results Orthologs to the P. falciparum trophozoite protein R45 were detected exclusively in protozoan parasites of the phylum Apicomplexa, including several Plasmodium spp., Toxoplasma gondii and Cryptosporidium parvum. All family members are hybrid genes with a conserved C-terminal protein kinase domain of a novel type, recently called FIKK kinase, associated with a non conserved N-terminal region without any known functional signature. While a single copy gene was detected in most species, considerable gene expansion was observed in P. falciparum and its closest phylogenic relative P. reichenowi, with 20 and six copies, respectively, each with a distinct N-terminal domain. Based on full length protein sequence, pairs of orthologs were observed in closely related species, such as P. berghei and P.y. yoelii, P. vivax and P. knowlesi, or P. reichenowi and P. falciparum. All 20 P. falciparum paralogs possess a canonical Plasmodium export element downstream of a signal / anchor sequence required for exportation outside the parasitophorous vacuole. This is consistent with the reported association of the trophozoite protein R45, the only paralog characterised to date, with the infected red blood cell membrane. Interestingly, most genes are located in the subtelomeric region of chromosomes, in association with other multigene families contributing to the remodelling of the infected red blood cell membrane, in particular the ring erythrocyte surface

  14. Aggregata (Protozoa: Apicomplexa) infection in the common octopus Octopus vulgaris from the West Mediterranean Sea: The infection rates and possible effect of faunistic, environmental and ecological factors

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    Mayo-Hernández, E.; Barcala, E.; Berriatua, E.; García-Ayala, A.; Muñoz, P.

    2013-10-01

    Prevalence and distribution of the coccidian parasite Aggregata octopiana (Protozoa: Apicomplexa) in common octopus (Octopus vulgaris) in the Mediterranean Spanish coasts were studied. A total of 114 octopuses were sampled from 30 geographic sectors by trawl fleet, and whitish macroscopic oocysts typical of A. octopiana infection were recorded in 96% of octopuses in the digestive tract and mainly in intestine and spiral caecum. The univariate analysis showed that lesion extension varied according to specific octopus, environmental and faunistic variables. A subsequent multivariable analysis indicated that the risk of macroscopic lesions in the caecum was greater in males compared to females, in octopuses living in deeper compared to shallower waters and in hauls where the crustacean Pagurus excavatus was present. The study provides further evidence of the abundance of A. octopiana in octopus ecosystems urging for further studies to evaluate its health impact. The combined abundance of infected octopuses and P. excavatus merits attention.

  15. A new species of Caryospora Léger, 1904 (Apicomplexa: Eimeriidae) from the snake Philodryas olfersii Lichtenstein (Colubridae) from a coastal habitat in Brazil.

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    Viana, Lúcio A; Winck, Gisele R; Coelho, Cleide D; Flausino, Walter; Duarte Rocha, Carlos F

    2013-06-01

    A new coccidian species of the genus Caryospora Léger, 1904 (Protozoa, Apicomplexa, Eimeriidae) is reported from the colubrid snake host Philodryas olfersii Lichtenstein at a coastal area in the State of Rio de Janeiro, south-eastern Brazil. Oöcysts of Caryospora olfersii n. sp. are spherical to sub-spherical, 33.1 × 31.2 μm, with smooth, colourless, three-layered wall, c.1.4; middle layer lightly striated. Micropyle, oöcyst residuum and polar granule are all absent. Sporocysts are ovoid, 22.9 × 17.4 μm on average, with one extremity in the shape of a short neck. Stieda body present, 3.2 × 1.3 μm, sub-Stieda body present, homogeneous, larger than Stieda body, 4.5 × 1.7 μm. Sporozoites are inserted in a bulky sporocyst residuum. PMID:23673697

  16. Molecular assessment of Hepatozoon (Apicomplexa: Adeleorina) infections in wild canids and rodents from north Africa, with implications for transmission dynamics across taxonomic groups.

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    Maia, João P; Alvares, Francisco; Boratyński, Zbyszek; Brito, José C; Leite, João V; Harris, D James

    2014-10-01

    Parasites play a major role in ecosystems, and understanding of host-parasite interactions is important for predicting parasite transmission dynamics and epidemiology. However, there is still a lack of knowledge about the distribution, diversity, and impact of parasites in wildlife, especially from remote areas. Hepatozoon is a genus of apicomplexan parasites that is transmitted by ingestion of infected arthropod vectors. However, alternative modes of transmission have been identified such as trophic transmission. Using the 18S rRNA gene as a marker, we provide an assessment of Hepatozoon prevalence in six wild canid and two rodent species collected between 2003 and 2012 from remote areas in North Africa. By combining this with other predator-prey systems in a phylogenetic framework, we investigate Hepatozoon transmission dynamics in distinct host taxa. Prevalence was high overall among host species (African jerboa Jaculus jaculus [17/47, 36%], greater Egyptian jerboa Jaculus orientalis [5/7, 71%], side-striped jackal Canis adustus [1/2, 50%], golden jackal Canis aureus [6/32, 18%], pale fox Vulpes pallida [14/28, 50%], Rüppell's fox Vulpes rueppellii [6/11, 55%], red fox Vulpes vulpes [8/16, 50%], and fennec fox Vulpes zerda [7/11, 42%]). Phylogenetic analysis showed further evidence of occasional transmission of Hepatozoon lineages from prey to canid predators, which seems to occur less frequently than in other predator-prey systems such as between snakes and lizards. Due to the complex nature of the Hepatozoon lifecycle (heteroxenous and vector-borne), future studies on these wild host species need to clarify the dynamics of alternative modes of Hepatozoon transmission and identify reservoir and definitive hosts in natural populations. We also detected putative Babesia spp. (Apicomplexa: Piroplasmida) infections in two canid species from this region, V. pallida (1/28) and V. zerda (1/11). PMID:25050803

  17. Morpho-functional characterization and esterase patterns of the midgut of Tribolium castaneum Herbst, 1797 (Coleoptera: Tenebrionidae) parasitized by Gregarina cuneata (Apicomplexa: Eugregarinidae).

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    Gigliolli, Adriana A Sinópolis; Lapenta, Ana Silva; Ruvolo-Takasusuki, Maria Claudia Colla; Abrahão, Josielle; Conte, Hélio

    2015-09-01

    Tribolium castaneum (Coleoptera: Tenebrionidae) is a common pest of stored grains and byproducts and is normally infected by Gregarina cuneata (Apicomplexa: Eugregarinidae). The life cycle of this parasite includes the sporozoite, trophozoite, gamont, gametocyte, and oocyst stages, which occur between the epithelium and lumen of the host's midgut. This study aims to describe the morphofunctional alterations in the midgut and determine the esterase patterns in T. castaneum when parasitized by gregarines. To achieve this purpose, midguts of adult insects were isolated, processed, and analysed using light and electron microscopy. We determined total protein content, amylase activity, and the expression and related activities of the esterases by using polyacrylamide gel electrophoresis (PAGE). The midgut of T. castaneum is formed by digestive, regenerative, and endocrine cells. The effects of parasitism on the digestive cells are severe, because the gregarines remain attached to these cells to absorb all the nutrients they need throughout their development. In these cells, the most common alterations observed include expansion and fragmentation of the rough endoplasmic reticulum, development of the smooth endoplasmic reticulum, changes in mitochondrial cristae, cytoplasmic vacuolization, formation of myelin structures, spherites, large intercellular spaces, autophagic vesicles, expansion of the basal labyrinth, and cytoplasmic protrusions. Deposits of glycogen granules were also observed. Amylase activity was reduced in parasitized insects. Regenerative cells were found in disorganized crypts and did not differentiate into new cells, thus, compromising the restoration of the damaged epithelium. Though few morphological alterations were observed in the endocrine cells, results suggest that the synthesis and/or release of hormones might be impaired. Nine esterases (EST-1 to 9) were identified in the midgut of T. castaneum and were expressed in varying levels in response

  18. Research Advances in Calcium-dependent Protein Kinases of Apicomplexa%顶复门原虫钙依赖蛋白激酶的研究进展

    Institute of Scientific and Technical Information of China (English)

    张念章; 陈佳; 王萌; 朱兴全; 黄思扬

    2013-01-01

    钙依赖蛋白激酶(Calcium-dependent protein kinases,CDPKs)是一类大的蛋白激酶家族,属于丝氨酸/苏氨酸类蛋白激酶,广泛存在于各种植物和原生动物中,参与多种生命活动的调控.随着生物信息学、分子生物学及基因工程的迅速发展,对顶复门原虫CDPKs的研究日益增多.研究结果表明,这类蛋白家族成员参与调控寄生虫入侵、外出宿主细胞、配子形成、宿主体内移行等顶复门原虫生活史的多个重要时期,其特殊的分子结构或可成为研究抗寄生虫疫苗或药物的候选靶标.本文以疟原虫、弓形虫和艾美耳球虫CDPKs为重点,综述了顶复门原虫CDPKs的结构、功能及生物学意义,展望了顶复门原虫CDPKs的研究和应用前景,以期为研究顶复门原虫的致病机理及研发抗原虫生物制剂提供参考.%Calcium-dependent protein kinases (CDPKs) are a large gene family, which is one kind of serine-threonine protein kinases. CDPKs have a diverse array of functions in various plants and many protozoa. With the development of bioinformatics, molecular biology and gene engineering, increasing numbers of researches about CDPKs were published recently. Increasing evidence suggests that CDPKs can regulate many crucial steps of parasite's life cycle including host cell invasion and egress, gamete formation, and gliding motility. The special structure compared with proteins in human and mammal makes CDPKs an ideal target for novel vaccine and anti-parasite therapeutic drugs. This article reviews the structures, functions and applications of Apicomplexa 's CDPKs focusing on Plasmodium, Toxoplasma gondii and Eimeria, and prospects the research and application tendency, in order to provide references for the research of the pathogene-sis and biological agents against Apicomplexan parasites.

  19. Utilización del patrón de restricción del DNA codificante para el RNA Ribosomal de la subunidad pequeña para la caracterización de Apicomplexa

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    López Adelaida

    1996-12-01

    Full Text Available Los Apicomplexos constituyen un phylum de protozoarios que se caracterizan por ser parásitos obligados de una gran variedad de huéspedes vertebrados e invertebrados. Hoy en día hay fuertes polémicas en tomo a su clasificación taxonómica, sus relaciones filogenéticas, y los patrones de coevolución con sus hospederos. El gen que codifica para el ARN ribosomal de la subunidad pequeña (ARN-SURp se utiliza como marcador molecular para resolver estas inquietudes. A partir del ADN de las especies de la familia Sarcocystidae (Sarcocystis cruzi, Sarcocystis sp. de Didelphis marsupialis y Sarcocystis sp. de Columbina talpacoti y Toxoplasma gondii, y de especies de la familia Plasmodiidae (Plasmodium de Anolis chloris, P. simium, y P. falciparumi, se amplificó por PCR el gen que codifica para el ARN de la subunidad ribosomal pequeña (ARN- SURp usando los iniciadores P5-P3, 0009-2134 Y566R-567R. Se compararon
    los patrones de restricción Hind III, Eco RI, Sau 3AI y Alw 261 del DNA ribosomal. La prueba de riboprini mostró que además de discriminar entre familias permite caracterizar diferencias a nivel de género y especie.Apicomplexa is a Protozoa phylum in which all members are obliged parasites of a wide range of vertebrate and invertebrate hosts. There is an ongoing controversy on
    systematics, phylogenetic relationships and parasite - host coevolution patterns. The SSU ribosomal gen has been used as a molecular marker in order to solve these issues.
    From DNA of the species of the Sarcocystidae family (Sarcocystis cruzi, Sarcocystis sp. from Didelphis marsupialis, Sarcocystis sp. from Columbina talpacoti and Toxoplasma
    gondii, and from the species of the Plasmodiidae family (Plasmodium from Anolis ehloris, P. simium, and P. falciparum, the SSU ribosomal DNA fragemnt was
    amplified by PCR, using the pair of primers P5-P3, 0009-2134 and 566R-567R. Hind III, Eco RI, Sau 3AI and Alw 261 restriction pattems were compared

  20. Observations on some Avian Coccidia (Apicomplexa: Eimeriidae in Amazonian Brazil

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    Ralph Lainson

    1994-09-01

    Full Text Available Oocysts of Eimeria porphyrulae n. sp. are described in faeces of Porphyrula martinica (Aves: Gruiformes: Rallidae. They are ellipsoidal to oval, 22.4 x 17.7 (20.0-23.7 x 16.2-18.7 µm, shape-index (length/width 1.3. Oocyst wall about 1.25 µm thick, colourless, with two layers: inner one prominently striated. Micropyle and sub-micropylar granule present: no oocyst residuum. Sporocysts 17.5 x 9.0 (17.0-19.0 x 8.0-10.0 µm, shape-index 1.9, with inconspicuous Stieda/sub-Stieda bodies. Sporocyst residuum of scattered granules, sometimes a compact mass: sporozoites with two refractile bodies. Eimeria crypturelli n. sp. is described in faeces of Crypturellus soiu (Tinamiformes: Tinamidae. Oocysts ellipsoidal-oval, 20.75 x 14.5 (17.5-25.0 x 11.25-21.25 µm, shape-index 1.4. Oocysts wall about 1.25 µm thick and bi-layered: inner layer faintly striated. Micropyle present, with oocyst residuum immediately below: single polar body rarely present. Sporocysts 13.0 x 7.5 (12.5-13.75 x 7,5-8.1 µm, shape-index 1.7, with a Stieda body but seemingly no sub-Stieda. Sporocyst residuum compact: sporozoites with two refractile bodies. Isospora cacici n. sp. is recorded from faeces of Cacicus cela cela (Passeriformes: Icteridae. Oocysts subspherical-spherical, 26.5 x 23.7 (22.5-27.5 x 20.0-26.2 µm, shape-index 1.1. Wall a single, colourless layer about 1.5 µm thick. No micropyle or oocyst residuum: 1-2 polar bodies. Sporocysts ellipsoidal, 17.7 x 12.5 (17.5-18.75 x 11.25-13.75 µm, shape-index 1.4, with pronounced Stieda/sub-Stieda bodies: residuum compact and sporozoites with two refractile bodies. Isospora thraupis n. sp. is described from faeces of Thraupis palmarum melanoptera (Passeriformes: Thraupidae. Oocysts subspherial-spherical, 19.9 x 19.0 (18.7-21.2 x 18.75-20.0 µm, shape-index 1.0. Wall about 0.6 µm thick, smooth, colourless and a single layer: no micropyle, oocyst residuum or polar bodies. Sporocysts 14.2 x 9.2 (13.7-16.2 x 8.7-10.0 µm, shape-index 1.5: Stied/sub-Stieda bodies inconspicuous. Residuum compact: sporozoites with two refractile bodies.

  1. Phylogeny of Fish-Infecting Calyptospora species (Apicomplexa: Eimeriorina)

    Science.gov (United States)

    There are numerous species of apicomplexans that infect poikilothermic vertebrates such as fishes, and possess unique morphological features that provide insight into the evolution of this important phylum of parasites. Here the relationship of the fish-infecting Calyptospora spe...

  2. Cryptosporidium erinacei n. sp. (Apicomplexa: Cryptosporidiidae) in hedgehogs.

    Science.gov (United States)

    Kváč, Martin; Hofmannová, Lada; Hlásková, Lenka; Květoňová, Dana; Vítovec, Jiří; McEvoy, John; Sak, Bohumil

    2014-03-17

    The morphological, biological, and molecular characteristics of Cryptosporidium hedgehog genotype are described, and the species name Cryptosporidium erinacei n. sp. is proposed to reflect its specificity for hedgehogs under natural and experimental conditions. Oocysts of C. erinacei are morphologically indistinguishable from Cryptosporidium parvum, measuring 4.5-5.8 μm (mean=4.9 μm) × 4.0-4.8 μm (mean=4.4 μm) with a length to width ratio of 1.13 (1.02-1.35) (n=100). Oocysts of C. erinacei obtained from a naturally infected European hedgehog (Erinaceus europaeus) were infectious for naïve 8-week-old four-toed hedgehogs (Atelerix albiventris); the prepatent period was 4-5 days post infection (DPI) and the patent period was longer than 20 days. C. erinacei was not infectious for 8-week-old SCID and BALB/c mice (Mus musculus), Mongolian gerbils (Meriones unguiculatus), or golden hamsters (Mesocricetus auratus). Phylogenetic analyses based on small subunit rRNA, 60 kDa glycoprotein, actin, Cryptosporidium oocyst wall protein, thrombospondin-related adhesive protein of Cryptosporidium-1, and heat shock protein 70 gene sequences revealed that C. erinacei is genetically distinct from previously described Cryptosporidium species. PMID:24529828

  3. Life cycle of Hammondia hammondi (Apicomplexa: Sarcocystidae) in cats

    Science.gov (United States)

    Hammondia hammondi and Toxoplasma gondii are feline coccidian that are morphologically, antigenically, and phylogenitically related. Both parasites multiply asexually and sexually in feline intestinal enterocytes but H. hammondi remains confined to enterocytes whereas T. gondii also parasitizes extr...

  4. Building the perfect parasite: cell division in apicomplexa.

    Directory of Open Access Journals (Sweden)

    Boris Striepen

    2007-06-01

    Full Text Available Apicomplexans are pathogens responsible for malaria, toxoplasmosis, and crytposporidiosis in humans, and a wide range of livestock diseases. These unicellular eukaryotes are stealthy invaders, sheltering from the immune response in the cells of their hosts, while at the same time tapping into these cells as source of nutrients. The complexity and beauty of the structures formed during their intracellular development have made apicomplexans the darling of electron microscopists. Dramatic technological progress over the last decade has transformed apicomplexans into respectable genetic model organisms. Extensive genomic resources are now available for many apicomplexan species. At the same time, parasite transfection has enabled researchers to test the function of specific genes through reverse and forward genetic approaches with increasing sophistication. Transfection also introduced the use of fluorescent reporters, opening the field to dynamic real time microscopic observation. Parasite cell biologists have used these tools to take a fresh look at a classic problem: how do apicomplexans build the perfect invasion machine, the zoite, and how is this process fine-tuned to fit the specific niche of each pathogen in this ancient and very diverse group? This work has unearthed a treasure trove of novel structures and mechanisms that are the focus of this review.

  5. Isospora bocamontensis (Protozoa: Apicomplexa in captive yellow cardinal Gubernatrix cristata (Passeriformes: Emberezidae Isospora bocamontensis (Protozoa: Apicomplexa em cardeais-amarelo Gubernatrix cristata (Passeriformes: Emberezidae mantidos em cativeiro

    Directory of Open Access Journals (Sweden)

    Larissa Quinto Pereira

    2013-03-01

    Full Text Available The yellow cardinal (Gubernatrix cristata is a passerine found in southern Brazil, especially along the border with Uruguay and Argentina. It is an endangered species and its population is decreasing. Among the parasites that affect passerines, the genus Isospora is the most easily found in both captive and free-living birds. This parasite commonly causes injury to the intestinal tissue and could occasionally affect other organs. In this work we examined the occurrence of coccidiosis in captive yellow cardinals and its association with factors such as sex, use of parasiticides, type of enclosure, contact with feces, type of food and cleaning frequency. We collected fecal samples of 45 yellow cardinals, healthy and kept in captivity, in late afternoon at the end of the reproductive period. The examination showed parasitic infection by Isospora bocamontensis in 44.5% of the birds. This infection is not influenced by the sex of birds, but is significantly affected by the type of enclosure, contact with the feces, use of parasiticides, type of food and cleaning frequency. The results indicate that to keep yellow cardinals captive, these factors must be observed.O cardeal-amarelo (Gubernatrix cristata é um pássaro que ocorre no sul do Brasil, principalmente na fronteira com Uruguai e Argentina. É uma ave ameaçada de extinção e sua população está decrescendo. Dentre, os parasitas que afetam a ordem Passeriformes, o gênero Isospora está entre o mais encontrado, tanto em aves de cativeiro quanto em aves de vida-livre. Comumente causam injúrias no tecido intestinal, podendo ocasionalmente afetar outros órgãos. Neste trabalho examinamos a ocorrência de coccidiose em cardeais mantidos em cativeiro e verificamos sua associação com fatores como sexo, uso de produtos parasiticidas, tipo de recinto, contato com fezes, tipo de alimentação e frequência de limpeza. Foram coletadas amostras de fezes, ao entardecer, de 45 cardeais-amarelos, hígidos, mantidos em cativeiro, no final do período reprodutivo. O exame coproparasitológico revelou infecção parasitária por Isospora bocamontensis, em 44,5% das aves. Esta infecção não é influenciada pelo sexo das aves, mas é significativamente afetada pelo tipo de recinto, contato com as fezes, uso de parasiticidas, tipo de alimentação e frequência de limpeza. Indicando que para a manutenção em cativeiro estes fatores devem ser observados.

  6. Sarcocystis cruzi (Apicomplexa: Sarcocystidae no cachorro-do-mato (Cerdocyon thous Sarcocystis cruzi (Apicomplexa: Sarcocystidae in the crab-eating fox (Cerdocyon thous

    Directory of Open Access Journals (Sweden)

    Janaina S. Rodrigues

    2008-11-01

    Full Text Available Esporocistos de Sarcocystis foram identificados nas amostras fecais de um cachorro-do-mato. Eles foram dados por via oral para um bezerro em aleitamento, sendo observados cistos com morfologia compatível com os de Sarcocystis cruzi na musculatura cardíaca e esquelética, três meses após a infecção. Musculatura cardíaca deste bezerro foi dada para um segundo cão doméstico livre de coccídios, que eliminou esporocistos compatíveis com os de Sarcocystis em suas fezes, tendo com períodos pré-patente e patente 11 e 12 dias após a infecção respectivamente. Para comparar a morfologia dos esporocistos e cistos, um segundo cão, também livre de coccídios, foi alimentado com musculatura cardíaca de um bovino infectando naturalmente e positivo para cistos de S. cruzi. Esporocistos compatíveis com os eliminados pelo primeiro cão foram encontrados nas fezes. Apesar dos esporocistos eliminados pelo cachorro-do-mato serem significativamente diferentes dos eliminados pelos cães infectados experimentalmente, pode se considerar com base na morfologia dos esporocistos, cistos e na transmissão biológica que a espécie encontrada nas fezes do cachorro-do-mato é Sarcocystis cruzi.Sporocysts of Sarcocystis were identified in feces samples of a crab-eating fox, and were orally given to a suckling calf; after 3 months of infection, sarcocysts morphologically similar to Sarcocystis cruzi were observed in cardiac and skeletal striated muscles. The cardiac muscles of this calf were orally given to a puppy free of coccidia, that shed sporocysts in its feces.with a prepatent and patent period of 11 and 12 days after infection, respectively. To compare the morphology of the sporocysts and cysts, a second puppy was fed on bovine cardiac muscles infected naturally, and sporocysts identical to those shed by the first dog were recovered from its feces. In spite of the significant difference between sporocysts found in the mucosa of the crab-eating fox and those shed by the first and second puppies, the species observed in this study was considered to be Sarcocystis cruzi, based on size of the sporocyts, morphology of the cyst wall, and the pray-predator cycle.

  7. Morphologic and morphometric analysis of Hepatozoon spp. (Apicomplexa, Hepatozoidae of snakes

    Directory of Open Access Journals (Sweden)

    Moço Tatiana Cristina

    2002-01-01

    Full Text Available Hepatozoon species are the most abundant hemoparasites of snakes. Its identification has been based mainly on the morphologic characterization of the gamonts in the peripheral blood of the vertebrate host and also of the cysts found in the internal organs of the vertebrate and invertebrate hosts. Using a computerized image analysis system, we studied five species of Hepatozoon from recently captured snakes in Botucatu, State of São Paulo, Brazil, to evaluate the importance of the morphology and morphometry of the gamonts for the characterization of Hepatozoon species and to analyze the morphologic changes induced in the erythrocytes by the parasite. The studied species were H. terzii of Boa constrictor amarali, Hepatozoon sp. of Crotalus durissusterrificus, H. philodryasi of Philodryas patagoniensis, and H. migonei and H. cyclagrasi of Hydrodynastes gigas. We observed three different groups, one of them including the species H. terzii, H. philodryasi and Hepatozoon sp. of C. durissus terrificus; and the other two consisting of H. migonei and H. cyclagrasi. Degree of alterations in the erythrocytes was variable and it may be useful for characterization of Hepatozoon species.

  8. Schellackia (Apicomplexa: Eimeriidae of the brazilian tree-frog, Phrynohyas venulosa (Amphibia: Anura from Amazonian Brazil

    Directory of Open Access Journals (Sweden)

    I. Paperna

    1995-10-01

    Full Text Available Endogenous stages of a Schellackia species are described in histological sections of the intestine of the tree-frog, Phrynohyas venulosa, from North Brazil. Most oocysts sporulate within the epithelial cells of the gut, but a few were detected in the lamina propria.

  9. A description of Isospora amphiboluri (Apicomplexa: Eimeriidae) from the inland bearded dragon, Pogona vitticeps (Sauria: Agamidae).

    Science.gov (United States)

    McAllister, C T; Upton, S J; Jacobson, E R; Kopit, W

    1995-04-01

    Fecal samples from 50 captive inland bearded dragons, Pogona vitticeps (Ahl, 1926), bred in California, were examined for coccidian parasites. Sixteen (32%) of the lizards were found to be passing oocysts of Isospora amphiboluri Cannon, 1967, previously described from bearded dragons Pogona barbata (Cuvier, 1829) from Australia. Sporulated oocytes were spherical to subspherical, 25.3 x 25.1 (23-26 x 23-26) microns, with a shape index (length/width) of 1.0 (1.0-1.1). A micropyle, oocyst residuum, and polar granule were absent. Sporocyts were ovoidal, 17.0 x 11.4 (16-18 x 11-12) microns, with a shape index of 1.5 (1.4-1.7). A sporocyst residuum, Stieda, and substieda bodies were present, but parastieda bodies were absent. Sporozoites were elongated, 13.9 x 3.5 (12-15 x 3-4) microns in situ, containing spherical anterior and posterior refractile bodies. The occurrence of I. amphiboluri in P. vitticeps is a new host and geographic record for the parasite. Photomicrographs of the oocysts and endogenous life cycle stages of I. amphiboluri are presented for the first time. PMID:7707208

  10. Hemosporid (Apicomplexa, Hematozoea, Hemosporida) community structure off pattern in wintering wild turkeys.

    Science.gov (United States)

    Fedynich, A M; Rhodes, O E

    1995-07-01

    The hemosporid community of 76 wild turkeys (Meleagris gallopavo silvestris) from South Carolina (USA) was examined using thin blood smears collected during January and February 1994. High prevalences and low abundances of hemosporids characterized this community. Leucocytozoon smithi and Haemoproteus meleagridis occurred in 100% and 54% of the turkeys, respectively; a Plasmodium sp. was found in one bird. Prevalence of H. meleagridis was significantly higher in juvenile turkeys than adults, but prevalences did not differ significantly among four trap sites or by host sex. Mean (+/- SE) intensities of L. smithi, H. meleagridis, and Plasmodium sp. were 3.4 +/- 0.4, 1.8 +/- 0.3, and 3.0 per 10,000 erythrocytes, respectively. Abundances of L. smithi, H. meleagridis, and Plasmodium sp. were 3.4 +/- 0.9 +/- 0.2, and < 0.1 +/- < 0.1 per 10,000 erythrocytes, respectively. Juvenile turkeys had higher rank abundance values of L. smithi than adults, whereas no differences were found among trap sites or between sexes. No differences in rank abundances of H. meleagridis were found among trap sites, host age, or host sex variables. Collectively, both common hemosporid species varied by host age, reflecting higher abundances in juvenile turkeys. patterns of hemosporid prevalence appeared similar to patterns found in subtropical regions. Based on our data, we recommend using prevalence and abundance data to analyze the structure and pattern of hemosporid communities at the component community level.

  11. Three new species of Coccidia (Apicomplexa: Eimeriidae) from Skinks, Lipinia spp. (Sauria: Scincidae), from Oceania

    Science.gov (United States)

    McAllister, Chris T.; Duszynski, Donald W.; Austin, Christopher C.; Fisher, Robert N.

    2013-01-01

    Between September 1991 and March 1993, 25 moth skinks (Lipinia noctua) were collected from various localities on the Cook Islands, Fiji, Papua New Guinea (PNG), and Vanuatu and examined for coccidians. In addition, a single Roux's lipinia skink (Lipinia rouxi) was collected from PNG and examined for coccidia. Sixteen (64%) L. noctua were found to harbor 2 new eimerians, and L. rouxi harbored another new Eimeria sp. Oocysts of Eimeria lipinia n. sp. from 9 (36%) L. noctua from the Cook Islands, Fiji, and PNG were subspherical with a bilayered wall and measured (L × W) 18.6 × 16.9 μm, with a L/W ratio of 1.1. Both micropyle and oocyst residuum were absent, but a polar granule was present. Oocysts of Eimeria melanesia n. sp. from 6 (24%) L. noctua from Fiji and Vanuatu and a single L. rouxi from PNG were subspherical to ellipsoidal with a bilayered wall and measured 19.8 × 17.5 μm, and L/W was 1.1. Both micropyle and oocyst residuum were absent, but a single or fragmented polar granule was present. Oocysts of Eimeria lessoni n. sp. from 1 (4%) L. noctua from PNG were cylindroidal with a bilayered wall and measured 28.1 × 15.7 μm, and L/W was 1.8. Both micropyle and oocyst residuum were absent, but a single polar granule was present. These represent the third report of Eimeria spp. reported from any host on PNG and the only coccidians, to our knowledge, ever described from L. noctua and L. rouxi and from the Cook Islands and Vanuatu.

  12. Eimeria minasensis n. sp. (Apicomplexa: Eimeriidae in the Domestic Goat Capra hircus, from Brazil

    Directory of Open Access Journals (Sweden)

    Silva Andréa C

    1998-01-01

    Full Text Available Eimeria minasensis n. sp. is described in the domestic goat Capra hircus from Brazil. Oocysts ellipsoidal are 35 x 24.5 (32-37.7 x 20.9-27.9 mm. Sporocysts elongate-ellipsoid are 15.2 x 9 (12.3-18.4 x 7.8-10.2 mm, with a Stieda body at the narrow end. Oocyst wall smooth and bilayered; outer layer about 1.2 (0.8-1.6 mm and colorless; inner layer about 0.5 (0.4-0.8 mm and dark-brown. Micropyle, a mound-shaped micropylar cap 1,6 x 8,9 (0,8-2 x7-10,2 easily dislodged; one or more oocyst polar granules present. Oocyst residuum absent. Sporocyst residuum present, composed of many scattered granules. Sporozoites elongate, lying lengthwise, "head to tail" in the sporocysts; one or two refractile globules are usually visible. Sporulation time was 120 hr at 27oC, prepatent period, 19 to 20 days and patent period 15 to 25 days. Gamonts, gametes and oocysts present in cecum and colon. Prevalence was 12.8% (6/47 in goats from Minas Gerais, Brazil.

  13. A first glimpse into the pattern and scale of gene transfer in the Apicomplexa

    DEFF Research Database (Denmark)

    Huang, J.L.; Mullapudi, N.; Sicheritz-Pontén, Thomas;

    2004-01-01

    with a phylogenomic approach to detect potential gene transfers in four apicomplexan genomes. We have detected genes of algal nuclear, chloroplast (cyanobacterial) and proteobacterial origin. Plant-like genes were detected in species not currently harbouring a plastid (e.g. Cryptosporidium parvum) and putatively...

  14. Cryptosporidium huwi n. sp. (Apicomplexa: Eimeriidae) from the guppy (Poecilia reticulata).

    Science.gov (United States)

    Ryan, Una; Paparini, Andrea; Tong, Kaising; Yang, Rongchang; Gibson-Kueh, Susan; O'Hara, Amanda; Lymbery, Alan; Xiao, Lihua

    2015-03-01

    The morphological, biological, and molecular characteristics of Cryptosporidium piscine genotype 1 from the guppy (Poecilia reticulata) are described, and the species name Cryptosporidium huwi n. sp. is proposed to reflect its genetic and biological differences from gastric and intestinal Cryptosporidium species. Oocysts of C.huwi n. sp. over-lap in size with Cryptosporidium molnari, measuring approximately 4.4-4.9 µm (mean 4.6) by 4.0-4.8 µm (mean 4.4 µm) with a length to width ratio of 1.04 (0.92-1.35) (n = 50). Similar to C.molnari, C.huwi n. sp. was identified in the stomach only and clusters of oogonial and sporogonial stages were identified deep within the epithelium. However, phylogenetic analysis of 18S rRNA sequences indicated that C. huwi n. sp. exhibited 8.5-9.2% and 3.5% genetic distance from C.molnari isolates and piscine genotype 7 respectively. At the actin locus, the genetic distance between C.huwi n. sp. and C.molnari was 16.6%. The genetic distance between C.huwi n. sp. and other Cryptosporidium species at the 18S locus was 13.2%-17% and at the actin locus was 18.9%-26.3%. Therefore C. huwi n. sp. is genetically distinct from previously described Cryptosporidium species.

  15. Didelphis aurita (Marsupialia: Didelphidae): a new host for Sarcocystis lindsayi (Apicomplexa: Sarcocystidae).

    Science.gov (United States)

    da Silva Stabenow, Cristiane; Ederli, Nicole Brand; Lopes, Carlos Wilson Gomes; de Oliveira, Francisco Carlos Rodrigues

    2012-12-01

    Nine opossums, Didelphis aurita , were captured in the city of Seropédica, State of Rio de Janeiro, Brazil and examined for species of Sarcocystis. Sporocysts were observed in the mucosal scrapings of the small intestine from 3 opossums. Five budgerigars, Melopsittacus undulatus , were infected with sporocysts from each of these infected opossums and 5 budgerigars were used as controls. Of the 15 sporocyst-treated budgerigars, 5 birds that received sporocysts from 1 of the infected opossums developed tissue parasites. Meronts in the vascular endothelium of the lung venous capillaries and cysts in the skeletal and cardiac muscle cells were observed in histological sections stained with hematoxylin and eosin. The microscopic cysts, which were predominantly in the tongue and leg muscles, ranged from 65.3 to 118.1 μm in length and 14.0 to 29.4 μm in width and from 0.9 to 1.9 μm in thickness of the cystic wall. Sections examined by transmission electron microscopy revealed that the cyst wall contained numerous slender and jagged-shaped protrusions, each with a finger-like formation at the end. The morphology, especially of the cyst wall, and the morphometry of the tissue cysts indicate that the parasite is Sarcocystis lindsayi and, therefore, the opossum, D. aurita , is now considered a definitive host for this species in Brazil. PMID:22571294

  16. KLOSSIELLA DULCIS N. SP. (APICOMPLEXA: KLOSSIELLIDAE) IN THE KIDNEYS OF PETAURUS BREVICEPS (MARSUPIALIA: PETAURIDAE).

    Science.gov (United States)

    Ardiaca, Maria; Bennett, Mark D; Montesinos, Andres; Juan-Sallés, Carles; Soriano-Navarro, Mario

    2016-06-01

    Two cases of renal klossiellosis were diagnosed by histopathology in pet sugar gliders (Petaurus breviceps). In both cases, parasites were associated with tubular dilation and mild interstitial nephritis. Rare schizonts were seen in the proximal convoluted renal tubular epithelium, whereas all other life cycle stages were found within distal convoluted tubule cells or the urinary space of the structures distal to the loop of Henle. Conventional optical and transmission electron microscopies were used to assess the life stages of the parasite. The morphologic characteristics and measurements observed differ from those of previously described species of Klossiella infecting marsupial hosts, and the name Klossiella dulcis n. sp. is hereby proposed. This is the first report of a Klossiella sp. infection in Petaurus breviceps .

  17. Sarcocystis cafferi, n. sp. (Protozoa: Apicomplexa) from the African buffalo (Syncerus caffer)

    Science.gov (United States)

    Four species of Sarcocystis are currently recognized in the Asian water buffalo (Bubalus bubalis): Sarcocystis fusiformis with macrocysts and cats as definitive hosts, S. buffalonis also with macrocysts and cats as definitive hosts, S. levinei with microcysts and dogs as definitive hosts, and S. dub...

  18. Sarcocystis heydorni, n. sp. (Apicomplexa: Protozoa) with cattle (Bos taurus) and human (Homo sapiens) cycle

    Science.gov (United States)

    Cattle (Bos taurus) are intermediate hosts for four species of Sarcocystis, S. cruzi, S. hirsuta, S. hominis, and S. rommeli. Of these four species, mature sarcocysts of S. cruzi are thin-walled (< 1µm) whereas S. hirsuta, S. hominis, and S. rommeli have thick walls (4 µm or more). Here we describe ...

  19. CRYPTOSPORIDIUM HOMINIS N. SP (APICOMPLEXA : CRYPTOSPORIDIIDAE) FROM HOMO SAPIENS. (R826138)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Morphologic and morphometric analysis of Hepatozoon spp. (Apicomplexa, Hepatozoidae) of snakes

    OpenAIRE

    2002-01-01

    Hepatozoon species are the most abundant hemoparasites of snakes. Its identification has been based mainly on the morphologic characterization of the gamonts in the peripheral blood of the vertebrate host and also of the cysts found in the internal organs of the vertebrate and invertebrate hosts. Using a computerized image analysis system, we studied five species of Hepatozoon from recently captured snakes in Botucatu, State of São Paulo, Brazil, to evaluate the importance of the morphology a...

  1. Morphologic and morphometric analysis of Hepatozoon spp. (Apicomplexa, Hepatozoidae) of snakes.

    Science.gov (United States)

    Moço, Tatiana Cristina; O'Dwyer, Lucia Helena; Vilela, Fabiana Custódio; Barrella, Thomaz Henrique; da Silva, Reinaldo José

    2002-12-01

    Hepatozoon species are the most abundant hemoparasites of snakes. Its identification has been based mainly on the morphologic characterization of the gamonts in the peripheral blood of the vertebrate host and also of the cysts found in the internal organs of the vertebrate and invertebrate hosts. Using a computerized image analysis system, we studied five species of Hepatozoon from recently captured snakes in Botucatu, State of S o Paulo, Brazil, to evaluate the importance of the morphology and morphometry of the gamonts for the characterization of Hepatozoon species and to analyze the morphologic changes induced in the erythrocytes by the parasite. The studied species were H. terzii of Boa constrictor amarali, Hepatozoon sp. of Crotalus durissusterrificus, H. philodryasi of Philodryas patagoniensis, and H. migonei and H. cyclagrasi of Hydrodynastes gigas. We observed three different groups, one of them including the species H. terzii, H. philodryasi and Hepatozoon sp. of C. durissus terrificus; and the other two consisting of H. migonei and H. cyclagrasi. Degree of alterations in the erythrocytes was variable and it may be useful for characterization of Hepatozoon species. PMID:12563486

  2. First Molecular Identification of Sarcocystis ovicanis (Protozoa, Apicomplexa in the Brain of Sheep in Iran.

    Directory of Open Access Journals (Sweden)

    Mitra Salehi

    2014-06-01

    Full Text Available The objective of the present study was to survey the presence of Sarcocystis in sheep's brain in North Khorasan Province.In general, 80 samples of sheep's brain were collected from slaughtered sheep in slaughterhouses of North Khorasan Province. Tissue digestion method was used for observing bradyzoites in tissues. Histopathological processing tracing Sarcocystis and ensuing structural change in the brain tissue were conducted. PCR analysis was conducted on all the brain samples. Sequencing was done for one PCR product. Genotype was identified by Blast search and homology analysis.Sarcocystis spp. was found in one of the brain samples (1.25% using tissue digestion method. The presence of bradyzoite was also confirmed in the prepared histopathological sections. PCR analysis was positive in one of samples. Genotyping of one sample proved that Sarcocystis species was Sarcocystis ovicanis and the nucleotide sequence of this parasite was deposited in the GenBank database under accession number No.KF489431.Sarcocystis ovicanis can involve brain tissue of sheep and consequently causes clinical symptoms.

  3. Cryptosporidium rubeyi n. sp. (Apicomplexa: Cryptosporidiidae in multiple Spermophilus ground squirrel species

    Directory of Open Access Journals (Sweden)

    Xunde Li

    2015-12-01

    Full Text Available Previously we reported the unique Cryptosporidium sp. “c” genotype (e.g., Sbey03c, Sbey05c, Sbld05c, Sltl05c from three species of Spermophilus ground squirrel (Spermophilus beecheyi, Spermophilus beldingi, Spermophilus lateralis located throughout California, USA. This follow-up work characterizes the morphology and animal infectivity of this novel genotype as the final step in proposing it as a new species of Cryptosporidium. Analysis of sequences of 18S rRNA, actin, and HSP70 genes of additional Cryptosporidium isolates from recently sampled California ground squirrels (S. beecheyi confirms the presence of the unique Sbey-c genotype in S. beecheyi. Phylogenetic and BLAST analysis indicates that the c-genotype in Spermophilus ground squirrels is distinct from Cryptosporidium species/genotypes from other host species currently available in GenBank. We propose to name this c-genotype found in Spermophilus ground squirrels as Cryptosporidium rubeyi n. sp. The mean size of C. rubeyi n. sp. oocysts is 4.67 (4.4–5.0 μm × 4.34 (4.0–5.0 μm, with a length/width index of 1.08 (n = 220. Oocysts of C. rubeyi n. sp. are not infectious to neonatal BALB/c mice and Holstein calves. GenBank accession numbers for C. rubeyi n. sp. are DQ295012, AY462233, and KM010224 for the 18S rRNA gene, KM010227 for the actin gene, and KM010229 for the HSP70 gene.

  4. Sarcocystis neurona (Protozoa : Apicomplexa): Description of oocysts, sporocysts, sporozoites, excystation, and early development

    OpenAIRE

    Lindsay, D S; Mitchell, S. M.; Vianna, M. C.; Dubey, J. R.

    2004-01-01

    Equine protozoal myeloencephalitis is a major cause of neurological disease in horses from the Americas. Horses are considered accidental intermediate hosts. The structure of sporocysts of the causative agent, Sarcocystis neurona, has never been described. Sporocysts of S. neurona were obtained from the intestines of a laboratory-raised opossum fed skeletal muscles from a raccoon that had been fed sporocysts. Sporocysts were 11.3 by 8.2 mum and contained 4 sporozoites. The appearance of the s...

  5. Has Sarcocystis neurona Dubey et al., 1991 (Sporozoa: Apicomplexa: Sarcocystidae) cospeciated with its intermediate hosts?

    Science.gov (United States)

    Elsheikha, Hany M

    2009-08-26

    The question of how Sarcocystis neurona is able to overcome species barrier and adapt to new hosts is central to the understanding of both the evolutionary origin of S. neurona and the prediction of its field host range. Therefore, it is worth reviewing current knowledge on S. neurona host specificity. The available host range data for S. neurona are discussed in relation to a subject of evolutionary importance-specialist or generalist and its implications to understand the strategies of host adaptation. Current evidences demonstrate that a wide range of hosts exists for S. neurona. This parasite tends to be highly specific for its definitive host but much less so for its intermediate host (I.H.). The unique specificity of S. neurona for its definitive host may be mediated by a probable long coevolutionary relationship of the parasite and carnivores in a restricted ecological niche 'New World'. This might be taken as evidence that carnivores are the 'original' host group for S. neurona. Rather, the capacity of S. neurona to exploit an unusually large number of I.H. species probably indicates that S. neurona maintains non-specificity to its I.H. as an adaptive response to insure the survival of the parasite in areas in which the 'preferred' host is not available. This review concludes with the view that adaptation of S. neurona to a new host is a complex interplay that involves a large number of determinants. PMID:19375231

  6. Lankesterella poeppigii n. sp. (Apicomplexa, Lankesterellidae from Bufo poeppigii (Tschudi, 1845 from Peru

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    Ilan Paperna

    2011-07-01

    Full Text Available Lankesterella poeppigii n. sp. is described from Bufo poeppigii (Tschudi, 1845 from Peru. Merogony and oogony occur in the capillary endothelium and the macrophages in the liver, spleen and kidneys. Meronts are oval, 25,2–29,4 x 15,7–16,8 μm in size and yield 35–46 merozoites. Oocysts are 26,3–29,4 x 15,1–17,6 μm in size; sporozoites 9,2-9,8 x 4,2–5,0 μm in size, assemble in macrophages. Released 8,7–9,8 x 2,8–3,1 μm sporozoites enter erythrocytes. L. poeppigii is compared with Lankesterella petiti Lainson & Paperna, 1995 infecting Bufo marinus (Linnaeus, 1758 in Brazil. The above mentioned specific characters, added to differences in hosts and geographical location warrant the description of Lankesterella poeppigii from B. poeppigii as a new species.

  7. The first report of Hepatozoon sp. (Apicomplexa: Hepatozoidae) in neotropical felids from Brazil.

    Science.gov (United States)

    Metzger, Betina; dos Santos Paduan, Karina; Rubini, Adriano Stefani; de Oliveira, Tadeu Gomes; Pereira, Cristiane; O'Dwyer, Lucia Helena

    2008-03-25

    In order to investigate the occurrence of Hepatozoon infection in Neotropical felids from Brazil, blood from the jugular or cephalic vein was taken from 29 non-domestic felids including ocelot (Leopardus pardalis), little spotted cat (Leopardus tigrinus), margay (Leopardus wiedii), and jaguarondi (Puma yagouaroundi) from the Northeast region of Brazil. Hepatozoon infection was confirmed by light microscopy and molecular techniques. The results showed five naturally infected felids. Partial sequences of the 18S rRNA gene of the Hepatozoon sp. from these felids were further analyzed. Sequences revealed that the isolates found are closely related to Hepatozoon sp. from domestic cats in Spain. Hepatozoon species from Neotropical felids were identified molecularly and characterized for the first time. This is also the first report of Hepatozoon infection in a little spotted cat. PMID:18243562

  8. Molecular and morphologic characterization of Sarcocystis felis (Apicomplexa: Sarcocystidae) in South American wild felids from Brazil.

    Science.gov (United States)

    Cañón-Franco, William Alberto; López-Orozco, Natalia; Christoff, Alexandre Uarth; de Castilho, Camila Schlieper; de Araújo, Flavio Antônio Pacheco; Verma, Shiv Kumar; Dubey, J P; Soares, Rodrigo Martins; Gennari, Solange Maria

    2016-02-15

    Wild felids are thought to share parasites with domestic cats. However, little is known of the coccidian parasites of wild felids. We investigated the presence of Sarcocystis spp. in tissues of 6 species of 90 Neotropical small felids killed in road accidents in the state of Rio Grande do Sul, Brazil by using microscopic and molecular techniques. Formalin-fixed tissues from 28 felids were examined, and Sarcocystis felis-like sarcocysts were detected in 4 wild cats (2 Puma yagouaroundi and 2 Leopardus guttulus). By transmission electron microscopy, sarcocysts from a P. yagouaroundi were identical to S. felis from domestic cats in the USA. Direct sequencing of PCR amplicons resulted the unambiguous sequences of the ITS-1 region from 18 of the 31 PCR positive wild cats; 5 sequences from each P. yagouaroundi, and Leopardus geoffroyi, 4 sequences from L. guttulus, and 2 sequences from each Leopardus wiedii, and Leopardus colocolo. Sequences analysis of ITS-1 region revealed the highest identiy (97-99%) with that of previously describe isolates of S. felis from domestic cats in the USA and identified them as S. felis. Tissues of 1 Leopardus pardalis tested by PCR and histology were negative. The phylogenetic relationship indicated that S. felis is quite different to species which employ opossums as their definitive host. This is the first report of S. felis infection in small wild felids from Brazil. PMID:26827854

  9. Invasive Bombus terrestris (Hymenoptera: Apidae) parasitized by a flagellate (Euglenozoa: Kinetoplastea) and a neogregarine (Apicomplexa: Neogregarinorida).

    Science.gov (United States)

    Plischuk, Santiago; Lange, Carlos E

    2009-11-01

    The flagellate Crithidia bombi and the neogregarine Apicystis bombi have been found in individuals of Bombus terrestris, a Palaearctic species of bumble bee commercially reared and shipped worldwide for pollination services. B. terrestris has recently entered into the northwestern Patagonia region of Argentina from Chile, where it was introduced in 1998. Prevalence was 21.6% for C. bombi and 3.6% for A. bombi (n=111). The pathogens were not detected in 441 bumble bees belonging to five of the eight known Argentine native species (Bombus atratus, Bombus morio, Bombus bellicosus, Bombus opifex, Bombus tucumanus) collected elsewhere in the country. Although the absence of natural occurrence of C. bombi and A. bombi in Argentine native bumble bees cannot be ascertained at present due to the limited surveys performed, it is important to report their detection in invasive B. terrestris. The invasion event is relatively recent and the accompanying pathogens are not species specific within the genus Bombus. PMID:19682459

  10. Apicystis bombi (Apicomplexa: Neogregarinorida) parasitizing Apis mellifera and Bombus terrestris (Hymenoptera: Apidae) in Argentina.

    Science.gov (United States)

    Plischuk, Santiago; Meeus, Ivan; Smagghe, Guy; Lange, Carlos E

    2011-10-01

    The neogregarine Apicystis bombi is considered a low prevalence parasite of Bombus spp. Before our work it has only once been detected in one single specimen of the Western honeybee Apis mellifera. This contribution reports the presence of A. bombi parasitizing both A. mellifera and Bombus terrestris at a site in Northwestern Argentine Patagonia (Bariloche, close to the border with Chile) and analyses its possible absence in the Pampas region, the most important beekeeping region of the country. In Bariloche, prevalence of A. bombi in A. mellifera was 7.6% in 2009, and 13.6% in 2010, whereas in B. terrestris it was 12.1%. Infections were not detected in 302 bee hives periodically prospected along 3 years (almost 400 000 honeybee specimens) in the Pampas. Analysis with the probability program FreeCalc2 suggested a possible absence of A. bombi in this area. Because of high virulence showed in several species of Bombus in the Northern hemisphere, A. bombi should be closely monitored in A. mellifera and in native Bombus species or other Apidae. PMID:23761336

  11. Isospora bocamontensis (Protozoa: Apicomplexa in captive yellow cardinal Gubernatrix cristata (Passeriformes: Emberezidae

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    Larissa Quinto Pereira

    2013-03-01

    Full Text Available The yellow cardinal (Gubernatrix cristata is a passerine found in southern Brazil, especially along the border with Uruguay and Argentina. It is an endangered species and its population is decreasing. Among the parasites that affect passerines, the genus Isospora is the most easily found in both captive and free-living birds. This parasite commonly causes injury to the intestinal tissue and could occasionally affect other organs. In this work we examined the occurrence of coccidiosis in captive yellow cardinals and its association with factors such as sex, use of parasiticides, type of enclosure, contact with feces, type of food and cleaning frequency. We collected fecal samples of 45 yellow cardinals, healthy and kept in captivity, in late afternoon at the end of the reproductive period. The examination showed parasitic infection by Isospora bocamontensis in 44.5% of the birds. This infection is not influenced by the sex of birds, but is significantly affected by the type of enclosure, contact with the feces, use of parasiticides, type of food and cleaning frequency. The results indicate that to keep yellow cardinals captive, these factors must be observed.

  12. Cryptosporidium parvum (Apicomplexa: Cryptosporidiidae) oocyst and sporozoite antigens recognized by bovine colostral antibodies.

    OpenAIRE

    Tilley, M; Fayer, R; Guidry, A; Upton, S J; Blagburn, B L

    1990-01-01

    Colostral whey from seven hyperimmunized and two control cows (hyperimmune bovine colostrum) was examined by Western immunoblotting for the presence of antibody against oocysts and sporozoites of Cryptosporidium parvum, using rabbit anti-bovine immunoglobulin A (IgA), IgG1, IgG2, and IgM antibodies, followed by a horseradish peroxidase goat anti-rabbit polyvalent antibody. Although considerable variation was found in binding activity between cows on different immunization protocols, IgA and I...

  13. Life cycle of Cystoisospora felis (Coccidia: Apicomplexa) in cats and mice

    Science.gov (United States)

    Cystoisospora felis is a ubiquitous apicomplexan protozoon of cats. The endogenous development of C. felis was studied in cats after feeding them infected mice. For this, 5 newborn cats were killed at 24, 48, 72, 96, and 120 h after having been fed mesenteric lymph nodes and spleens of mice that wer...

  14. Endogenous Life Cycle of Eimeria marmosopos (Apicomplexa: Eimeriidae) from the Opossum, Didelphis marsupialis (Didelphimorphia: Didelphidae) in Costa Rica.

    Science.gov (United States)

    Chinchilla, Misael; Valerio, Idalia; Duszynski, Donald

    2015-08-01

    The endogenous life cycle of Eimeria marmosopos was studied in experimentally infected young opossums, Didelphis marsupialis . All the endogenous stages were located in the epithelial cells of villi in the small intestine. Giemsa-stained mucosal scrapings and histological sections were studied for the diagnosis of all the life cycle stages. Eimeria marmosopos has 3 generations of meronts (M) that differ by size, shape, and number of merozoites (m), which also differ in their size, shape, and location of their nuclei within the cytoplasm of the meronts. The 3 meront types, M(1)-M(3), respectively, had 8-15 (m(1)), 4-9 (m(2)), and 22-30 (m(3)) merozoites. Macrogametocytes and microgametocytes, as well as macrogametes and microgametes, completed the sexual cycle, finishing with the formation of unsporulated oocysts. This parasite's endogenous development produced severe intestinal lesions in experimentally infected opossums. There are 56 Eimeria species known from all marsupials worldwide, but this is the first complete life cycle in which both the asexual and sexual stages have been documented. PMID:25807059

  15. Tyzzeria boae n. sp., (Apicomplexa: Eimeriidae, a New Coccidium from the Kidney of the snake Boa constrictor constrictor (Serpentes: Boidae

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    Ralph Lainson

    1994-12-01

    Full Text Available A new species of Tyzzeria is described from the kidney of the snake Boa constrictor constrictor Linnaeus, from the State of Pará, north Brazil. Oocysts from the coacal contents matured in eight days, at approximately 24°C. They measured 19.0 x 18.0 (15.0 x 15.0 - 22.5 x 21.5 µm, shape-index (length/width 1.0 (1.0 - 1.1. The oocyst wall is of an extremely delicate single, colourless layer, with no micropyle. Division of the oocyst contents into the 8 naked sporozoites leaves a bulky, spherical oocyst residuum averaging 15.5 x 14.8 (13.5 x 13.5 - 18.5 x 17.5 µm; the sporozoites measure an average of 11.0 x 1.8 (8.5 x 1.25 - 12.5 x 2.0 µm, and possess both anterior and posterior refractile bodies. Tyzzeria boae n.sp. is unique among the recorded species of the genus by virtue of its development in the epithelial cells of the distal convoluted tubules and collecting tubules of the kidney: stages in the merogony and gametogony of the parasite are described and figured.

  16. Eimeria species (Apicomplexa: Eimeriidae of podocnemis expansa (Schweigger and geochelone denticulata (LINN. from Amazonian Brazil (Reptilia: Chelonia

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    Ralph Lainson

    1990-12-01

    Full Text Available Eimeria lagunculata, Eimeria mammiformis and Eimeria podocnemis n. spp., are described from the faeces of the fresh-water turtle Podocnemis expansa, in Pará State, north Brasil. Oocysts of E. lagunculata are ellipsoidal, 19.2 x 12.8 (17.0-20.7 x 11.8-14.1 mum, shape-index (= length/ width 1.5 (1.4-1.7. Oocyst wall about 0.5-0.7 mum thick, with a prominent stopper-like micropyle at one pole. No oocyst residuum and no polar body. Sporocysts elongate ellipsoidal, 11.0 x 5.4 (10.4-11.8 x 5.2-6.0 mum, shape-index 2.0 (1.8-2.1: no Stieda body. A compact, ellipsoidal sporocyst residuum lies between the two sporozoites, which possess a posterior and an anterior refractile body. Oocysts of E. mammiformis broadly ellipsoidal, 30.0 x 19.4 (23.0-37.0 x 16.3-21.5 mum, shape-index 1.5 (1.1-1.9. Oocyst wall about 0.7 mum thick, with a prominent micropyle: no oocyst residuum and rarely a single polar body. Sporocysts ellipsoidal, 15.3 x 7.9 (14.8-17.0 x 7.4-9.6 mum, shape-index 2.0 (1.8-2.2, with a tiny Stieda body. Sporocyst residuum bulky, ellipsoidal: sporozoites with two conspicuous refractile bodies. E. podocnemis has broadly ellipsoidal oocysts, 17.0 x 12.8 (14.8-19.2 x 11.8-14.1 mum, shape-index 1.3 (1.1-1.4. Oocyst wall about 0.5-0.7 mum thick, with no micropyle. No oocyst residuum, but always a single polar body. Sporocysts ellipsoidal, 9.7 x 5.2 (8.9-10.4 x 4.4-6.0 mum, shape-index 1.9 (1.6-2.0, with no Stieda body. Sporocyst residuum bulky, ellipsoidal: sporocysts with 2 refractile bodies. Eimeria carinii n. sp., is recorded from the tortoise Geochelone denticulata, also from Pará. Oocyst wall about 1.2 mum thicl. No micropyle. Oocyst residuum limited to a number (about 10-20 of scattered granules: no polar body. Sporocysts broadly ellipsoidal, and with no Stieda body: they measure 8,8 x 7.3 (8.0-9.0 x 7.0-7.5 mum, shape-index 1.2 (1.1-1.3. Sporocyst residuum bulky, spherical to ellipsoidal: sporozoites possess both posterior and anterior refractile bodies.

  17. Caryospora peneireiroi n. sp. (Apicomplexa: Eimeriidae) in the common kestrel, Falco tinnunculus (Falconiformes: Falconidae), in mainland Portugal.

    Science.gov (United States)

    Cardozo, Sergian Vianna; Berto, Bruno Pereira; Caetano, Inês; Maniero, Viviane Camara; Fonseca, Isabel Pereira da; Lopes, Carlos Wilson Gomes

    2016-06-01

    The common kestrel Falco tinnunculus Linnaeus, 1758, is a widespread raptor, native in Europe, Asia and Africa, and vagrant in the Americas. In the current work, 27 fecal samples were collected from common kestrels kept in the Lisbon Center for Wild Animal Recovery, located at Monsanto Forest Park, Lisbon, Portugal. Five (19%) of them were found to be passing an undescribed species of Caryospora in their feces. The oocysts of Caryospora peneireiroi n. sp. were ellipsoidal with a bilayered wall and measured 47.1 × 37.6 µm with a shape index of 1.25. No micropyle, oocyst residuum or polar granule was present. The sporocysts were subspherical, measuring 25.1 × 24.3 µm. Stieda, sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum was composed of many homogenous globules scattered throughout the periphery of the sporocyst. This is the fourth caryosporan species reported from F. tinnunculus. PMID:27334821

  18. Four new species of coccidia (Apicomplexa: Eimeriidae) from Owen Stanley Skinks, Papuascincus stanleyanus (Sauria: Scincidae), from Papua New Guinea

    Science.gov (United States)

    McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.; Austin, Christopher C.

    2014-01-01

    Between September and November 1991, 12 Owen Stanley skinks, Papuascincus stanleyanus (Booulenger) were collected from various localities on Papua New Guinea and examined for coccidians. Six (50%) were found to harbour four eimerians that we describe here as new. Oocysts of Eimeria burseyi sp. n. were elongate to ellipsoidal with a bilayered wall and measured (length x width, L x W) 36.0 x 24.0 microm, with a L/W ratio of 1.5. Both micropyle and oocyst residuum were absent, but a polar granule was present. Oocysts of Eimeria goldbergi sp. n. were ellipsoidal, with a bilayered wall, and measured 21.4 x 16.1 microm; L/W ratio was 1.3. Both micropyle and oocyst residuum were absent, but a single or fragmented polar granule was present. Oocysts of Eimeria boulengeri sp. n. were spheroidal to slightly subspheroidal, with a thin, single-layered wall that readily collapses, and measured 16.0 microm, L/W ratio was 1.0. Both micropyle and oocyst residuum were absent, but usually one (sometimes two) polar granule(s) were present. Oocysts of Eimeria niuginiensis sp. n. were oblong to tapered with a bilayered wall, and measured 20.0 x 13.1 microm; L/W ratio was 1.5. A micropyle, oocyst residuum and polar granule were absent. To our knowledge, these represent the only coccidians ever described from P. stanleyanus.

  19. Two new species of Eimeria (Apicomplexa, Eimeriidae) from tree skinks, Prasinohaema spp. (Sauria: Scincidae), from Papua New Guinea

    Science.gov (United States)

    McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.; Austin, Christopher C.

    2014-01-01

    Between September 1991 and June 1992, feces from 4 species of tree skinks, Prasinohaema spp. from Papua New Guinea, were collected and examined for coccidia. Two species, P. flavipes and P. prehensicauda were found to harbor eimerians which are described as new. Oocysts of Eimeria krausi sp. nov. from P. flavipes were ellipsoidal to subspheroidal with a smooth bilayered wall and measured (L × W) 19.2 × 16.9 μm, with a length/width (L/W) ratio of 1.1. Micropyle and oocyst residuum were absent but a fragmented polar granule was present. Sporocysts were ellipsoidal, 9.7 × 6.7 μm, L/W of 1.5. Stieda, subStieda and paraStieda bodies were absent. The sporocyst residuum was composed of many small granules in a compact mass between sporozoites. The sporozoites were sausage-shaped, 11.7 × 2.7 μm, in situ, with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. Oocysts of Eimeria greeri sp. nov. from P. prehensicauda were ellipsoidal with a smooth bilayered wall, (L × W) 23.0 × 18.3 μm, with a L/W of 1.3. Micropyle and oocyst residuum were absent but a fragmented polar granule was present. Sporocysts were ellipsoidal, 9.7 × 8.4 μm, with a L/W of 1.2. Stieda, subStieda and paraStieda bodies were absent. The sporocyst residuum was composed of many large granules in a compact mass between sporozoites. The sporozoites were sausage-shaped, with an ellipsoidal posterior refractile body and a spheroidal anterior refractile body. We document here the first report of coccidia from skinks of the genus Prasinohaema.

  20. Two new species of Eimeria (Apicomplexa: Eimeriidae from Asian geoemydid turtles Kachuga tentoria and Melanochelys trijuga (Testudines: Geoemydidae

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    Široký P.

    2005-03-01

    Full Text Available Coprological examination of ten Pink-ringed tent turtles Kachuga tentoria circumdata, recently imported from India, and three Burmese black turtles Melanochelys trijuga edeniana, imported from Myanmar, revealed the presence of two new species of Eimeria. Oocysts of Eimeria kachua n. sp. from K. t. circumdata are broadly oval to subspherical, 15.3 (13-18 × 13.9 (12-16 μm, with polar granule and subspherical oocyst residuum. Sporocyst elongatelly oval to spindle-shaped, 8.7 (7.5-10 × 4.9 (4-6 μm, with a knoblike Stieda body, covered with fine membranous cupola-like structures. Thin walled oocysts of Eimeria patta n. sp. from M. t. edeniana, have an irregular shape, influenced by the position of sporocysts, frequently with lobular irregularities, 12.6 (11-16 × 9.1 (7.5-12 μm. Sporocysts are oval to ellipsoidal, 5.8 (5-7 × 4.2 (3.5-5 μm.

  1. Eimeria pavoaegyptica sp. nov. (Apicomplexa: Eimeriidae in faeces of Indian peacocks, Pavo cristatus Linnaeus, 1758 (Galliformes: Phasianidae from Egypt

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    Ismail Saad El-Shahawy

    2010-12-01

    Full Text Available Coprological examination of 15 Indian peacocks, Pavo cristatus, revealed the presence of a coccidium species of the genus Eimeria, which apparently represents a previously undescribed species. Sporulation is exogenous and fully developed oocysts of Eimeria pavoaegyptica sp. nov. are ellipsoidal, with a dimension of 15 (13-16 × 12 (10-12.9 μm and with a shape index of 1.25 (1-1.3. The sporulated oocysts have no micropyle but enclose one large rectangular-shaped polar granule and an oocyst residuum. The oocysts have a distinct two-layered wall, which is ~1.7 μm thick. The outer layer has a smooth texture; it fills ~¾ of the total thickness and appears bicolored. The sporocysts are boat-shaped, of about 10 (9-11 × 4 (4-4.7 μm; their average shape-index is 2.5 μm with a small pointed Stieda body and a smooth, thin single-layered wall. No substieda body is detected. The sporocysts contain numerous, nearly uniform granular residua. The sporozoites are banana-shaped, 6 × 3 μm and each has two different-sized refractile bodies.

  2. Two new species of Isospora (Apicomplexa: Eimeriidae) from skinks Emoia spp. (Sauria: Scincidae), from Fiji and Papua New Guinea

    Science.gov (United States)

    McAllister, Chris T.; Duszynski, Donald W.; Fisher, Robert N.

    2013-01-01

    Between September and October 1991 and again during September 1992, skinks (Emoia spp.) were collected from various localities on Fiji and Papua New Guinea (PNG) and examined for coccidians. One of 4 (25%) De Vis' emo skinks (Emoia pallidiceps) from PNG harbored an undescribed species of Isospora in its feces. Oocysts of Isospora grinbikpelapalai n. sp. were ellipsoidal to subspheroidal, 18.1 × 14.9 (17–20 × 14–16) μm, with a bilayered wall and a length/width index (L/W) of 1.2. Both micropyle and oocyst residuum were absent, but a prominent polar granule was present. Sporocysts were ovoidal, 10.7 × 7.6 (10–11 × 7–8) μm, with a L/W index of 1.4. Stieda and sub-Stieda bodies were present, but para-Stieda bodies were absent. The sporocyst residuum consisted of large scattered globules dispersed between sporozoites. Sporozoites were elongate with spheroidal anterior and posterior refractile bodies. Isospora grinbikpelapalai was also found in 1 of 2 (50%) Pope's emo skinks (Emoia popei) from PNG. One of 13 (8%) white-bellied copper-striped skinks (Emoia cyanura), from Fiji, was passing another undescribed species of Isospora in its feces. Oocysts of Isospora casei n. sp. were elongate, 31.8 × 21.3 (28–35 × 18–24) μm, with a bilayered wall and a L/W index of 1.5. Micropyle, oocyst residuum, and polar granule were all absent. Sporocysts were ovoidal, 15.3 × 10.6 (14–16 × 10–12) μm, with a L/W index of 1.4. Stieda and sub-Stieda bodies were present, but para-Stieda bodies were absent. The sporocyst residuum consisted of scattered globules among sporozoites or as a cluster surrounding sporozoites. Sporozoites were elongate with spheroidal anterior and posterior refractile bodies. Isospora casei was also found in 1 of 2 (50%) Fiji slender treeskinks (Emoia concolor) from Fiji. This represents the first report of coccidia from Emoia spp. and, to our knowledge, the initial documentation of reptilian coccidia from herpetofauna from Papua New Guinea.

  3. Some new species of Caryospora (Apicomplexa: Eimeriidae from brazilian snakes, and a re-description of C. jararacae Carini, 1939

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    Ralph Lainson

    1991-09-01

    Full Text Available The mature ooxysts of six new species of Caryospora are described from the faeces of Brazilian snakes. They are differentiated from other species previously recorded from reptiles, largely on the size and shape of the oocyst and sporocyst, structure of the oocyst wall, and presence or absence of a polar body. C. paraensis n. sp., and C. carajasensis n. sp., are from the "false coral", Oxyrhopus petola digitalis; C. pseustesi n. sp., from the "egg-eater", Pseustes sulphureus sulphureus; C. epicratesi n. sp., from the "red boa", Epicrates cenchria cenchria; and C. micruri n. sp., and C. constancieae n. sp., from the "coral snake", Micrurus spixii spixii. A re-description is given of C. jararacae Carini, 1939, from the "jararaca" Bothrops atrox, embodying some additional morphological features.

  4. Rodents as intermediate hosts of Hepatozoon ayorgbor (Apicomplexa: Adeleina: Hepatozoidae) from the African ball python, Python regius?

    Science.gov (United States)

    Sloboda, Michal; Kamler, Martin; Bulantová, Jana; Votýpka, Jan; Modrý, David

    2008-03-01

    Two experimental trials were performed to elucidate the role of rodents in the life cycle of Hepatozoon species using snakes as intermediate hosts. In one trial, two ball pythons, Python regius Shaw, 1802 were force fed livers of laboratory mice previously inoculated with sporocysts of Hepatozoon ayorgbor Sloboda, Kamler, Bulantová, Votýpka et Modrý, 2007. Transmission was successful in these experimentally infected snakes as evidenced by the appearance of intraerythrocytic gamonts, which persisted until the end of trial, 12 months after inoculation. Developmental stages of haemogregarines were not observed in histological sections from mice. In another experimental trial, a presence of haemogregarine DNA in mice inoculated with H. ayorgbor was demonstrated by PCR in the liver, lungs and spleen.

  5. Caryospora peneireiroi n. sp. (Apicomplexa: Eimeriidae in the common kestrel, Falco tinnunculus (Falconiformes: Falconidae, in mainland Portugal

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    Sergian Vianna Cardozo

    2016-01-01

    Full Text Available Abstract The common kestrel Falco tinnunculus Linnaeus, 1758, is a widespread raptor, native in Europe, Asia and Africa, and vagrant in the Americas. In the current work, 27 fecal samples were collected from common kestrels kept in the Lisbon Center for Wild Animal Recovery, located at Monsanto Forest Park, Lisbon, Portugal. Five (19% of them were found to be passing an undescribed species of Caryospora in their feces. The oocysts of Caryospora peneireiroi n. sp. were ellipsoidal with a bilayered wall and measured 47.1 × 37.6 µm with a shape index of 1.25. No micropyle, oocyst residuum or polar granule was present. The sporocysts were subspherical, measuring 25.1 × 24.3 µm. Stieda, sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum was composed of many homogenous globules scattered throughout the periphery of the sporocyst. This is the fourth caryosporan species reported from F. tinnunculus.

  6. Caryospora peneireiroi n. sp. (Apicomplexa: Eimeriidae) in the common kestrel, Falco tinnunculus (Falconiformes: Falconidae), in mainland Portugal.

    Science.gov (United States)

    Cardozo, Sergian Vianna; Berto, Bruno Pereira; Caetano, Inês; Maniero, Viviane Camara; Fonseca, Isabel Pereira da; Lopes, Carlos Wilson Gomes

    2016-06-01

    The common kestrel Falco tinnunculus Linnaeus, 1758, is a widespread raptor, native in Europe, Asia and Africa, and vagrant in the Americas. In the current work, 27 fecal samples were collected from common kestrels kept in the Lisbon Center for Wild Animal Recovery, located at Monsanto Forest Park, Lisbon, Portugal. Five (19%) of them were found to be passing an undescribed species of Caryospora in their feces. The oocysts of Caryospora peneireiroi n. sp. were ellipsoidal with a bilayered wall and measured 47.1 × 37.6 µm with a shape index of 1.25. No micropyle, oocyst residuum or polar granule was present. The sporocysts were subspherical, measuring 25.1 × 24.3 µm. Stieda, sub-Stieda and para-Stieda bodies were absent. The sporocyst residuum was composed of many homogenous globules scattered throughout the periphery of the sporocyst. This is the fourth caryosporan species reported from F. tinnunculus.

  7. Effects of Artemisia annua and Foeniculum vulgare on on chickens highly infected with Eimeria tenella (Phylum Apicomplexa)

    Science.gov (United States)

    Background: Intensive poultry production systems depend on chemoprophylaxis with anticoccidial drugs to combat infection. A floor-pen study was conducted to evaluate the anticoccidial effect of Artemisia annua and Foeniculum vulgare on Eimeria tenella infection. Five experimental groups were establi...

  8. Coccidia of the collared peccary (Tayassu tajacu) in southern Texas with descriptions of three new species of Eimeria (Apicomplexa: Eimeriidae).

    Science.gov (United States)

    Wilber, P G; Hellgren, E C; Gabor, T M

    1996-08-01

    In February 1993, fresh fecal samples were collected from 47 collared peccaries (Tayassu tajacu) killed by hunters at the Chaparral Wildlife Management Area, southern Texas, USA. Five species of coccidia (Eimeria chaparralensis n. sp. [9/47, 19%], Eimeria dicotylensis n. sp. [21/47, 21%], Eimeria pecari n. sp. [2/47, 4%], Eimeria sp. [1/47, 2%], and Klossia sp. [1/47, 2%]) were observed. Measurements are in micron. Sporulated oocysts of E. chaparralensis are rough-walled, elongate ovoidal, 43.3 x 28.5 (37-52 x 26-35); sporocysts are elongate ellipsoidal 21.8 x 9.0 (16-27 x 7-12); micropyle (approximately 4.9), Stieda, and substieda body are present; sporocyst residuum is present in newly sporulated oocysts; polar granule and oocyst residuum are absent. Sporulated oocysts of E. dicotylensis are smooth-walled, ovoidal, 25.7 x 20.1 (23-29 x 17-23); sporocysts are ellipsoidal 13.0 x 6.9 (11-17 x 6-9); micropyle and oocyst residuum are absent; polar body sometimes present; Stieda body and sporocyst residuum always present. Sporulated oocysts of E. pecari are smooth-walled, elongate ellipsoidal, 26.8 x 18.1 (22-31 x 15-21); sporocysts are elongate ellipsoidal 16.4 x 5.9 (13-22 x 4-7); micropyle (approximately 5.8) with collar, Stieda body, substieda body, and sporocyst residuum are present; polar granule and small oocyst residuum sometimes present. There were no sex or age differences in prevalences of infection, and there were no positive or negative associations between any species of eimerian. The majority of hosts were infected with a single species of Eimeria. Overall prevalence of infection with eimerians was 23/47 (49%).

  9. Morphologic and molecular characterization of the sarcocysts of Sarcocystis rileyi (Apicomplexa: Sarcocystidae) from the mallard duck ( Anas platyrhynchos ).

    Science.gov (United States)

    Dubey, J P; Rosenthal, B M; Felix, T A

    2010-08-01

    Macroscopic sarcocysts are often observed in ducks, but at present their taxonomic status remains uncertain because ducks serve as intermediate hosts for several such parasites in the genus Sarcocystis . One such species, Sarcocystis rileyi , was long ago established to involve the northern shoveler duck ( Anas clypeata ) and the striped skunk ( Mephitis mephitis ) as its intermediate and definitive hosts, respectively. Here, we employed light microscopy, electron microscopy, and DNA sequencing to more precisely describe diagnostic attributes of parasites presumed to represent S. rileyi occurring in a naturally-infected mallard duck ( Anas platyrhynchos ). By light and transmission electron microscopy, sarcocysts from the mallard duck resembled the S. rileyi described from A. clypeata . We document 18S, ITS-1, and 28S rDNA sequences from the mallard duck, the first for S. rileyi from any host. Sequences of conserved and variable portions of nuclear ribosomal DNA indicated that S. rileyi is related to, but distinct from, parasites employing opossums as their definitive host (including Sarcocystis neurona and Sarcocystis falcatula ). Diagnostic ultrastructural features and nucleotide sequences should aid in future studies and communications regarding this parasitic taxon, which lends itself to experimentation because its sarcocysts are macroscopic and easily excised from infected birds. PMID:20496959

  10. Identification of a divergent environmental DNA sequence clade using the phylogeny of gregarine parasites (Apicomplexa from crustacean hosts.

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    Sonja Rueckert

    Full Text Available BACKGROUND: Environmental SSU rDNA surveys have significantly improved our understanding of microeukaryotic diversity. Many of the sequences acquired using this approach are closely related to lineages previously characterized at both morphological and molecular levels, making interpretation of these data relatively straightforward. Some sequences, by contrast, appear to be phylogenetic orphans and are sometimes inferred to represent "novel lineages" of unknown cellular identity. Consequently, interpretation of environmental DNA surveys of cellular diversity rely on an adequately comprehensive database of DNA sequences derived from identified species. Several major taxa of microeukaryotes, however, are still very poorly represented in these databases, and this is especially true for diverse groups of single-celled parasites, such as gregarine apicomplexans. METHODOLOGY/PRINCIPAL FINDINGS: This study attempts to address this paucity of dna sequence data by characterizing four different gregarine species, isolated from the intestines of crustaceans, at both morphological and molecular levels: Thiriotia pugettiae sp. n. from the graceful kelp crab (Pugettia gracilis, Cephaloidophora cf. communis from two different species of barnacles (Balanus glandula and B. balanus, Heliospora cf. longissima from two different species of freshwater amphipods (Eulimnogammarus verrucosus and E. vittatus, and Heliospora caprellae comb. n. from a skeleton shrimp (Caprella alaskana. SSU rDNA sequences were acquired from isolates of these gregarine species and added to a global apicomplexan alignment containing all major groups of gregarines characterized so far. Molecular phylogenetic analyses of these data demonstrated that all of the gregarines collected from crustacean hosts formed a very strongly supported clade with 48 previously unidentified environmental DNA sequences. CONCLUSIONS/SIGNIFICANCE: This expanded molecular phylogenetic context enabled us to establish a major clade of intestinal gregarine parasites and infer the cellular identities of several previously unidentified environmental SSU rDNA sequences, including several sequences that have formerly been discussed broadly in the literature as a suspected "novel" lineage of eukaryotes.

  11. Microscopic and molecular characterization of Hepatozoon domerguei (Apicomplexa and Foleyella furcata (Nematoda in wild endemic reptiles from Madagascar

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    Maia João P.

    2014-01-01

    Full Text Available Madagascar is one of the world’s top twelve “megadiversity” hot spots hosting unique and threatened flora and fauna. Parasites are a major component of biodiversity but remain largely uncharacterized in wildlife. In this study we combine microscopic and molecular assessment of hemoparasites in endemic reptile species from Madagascar. We detected three distinct parasites: the apicomplexans Hepatozoon and Sarcocystis, and filarial nematodes. The prevalence and intensity of these apicomplexans were low overall, while microfilarial infections in chameleons were relatively high. We detected mixed infections of two Hepatozoon haplotypes in Madagascarophis colubrinus, and of Hepatozoon and microfilariae in a Furcifer sp. Phylogenetic analyses of Hepatozoon showed evidence of prey-predator transmission, with identical sequences found in the snakes M. colubrinus and Ithycyphus oursi, and their prey Furcifer sp. Based on previous studies regarding the life cycle of Hepatozoon domerguei Landau, Chabaud, Michel, and Brygoo, 1970 in these hosts and due to their morphological similarity, we propose that this Hepatozoon haplotype is Hepatozoon domerguei. Future studies, including the examination of invertebrate hosts, are needed to verify this preliminary taxonomic identification. A distinct hemogregarine haplotype was found in Oplurus sp., which displayed morphologically different gametocytes, some of which were apparently inside leukocytes. The Sarcocystis identified from Tracheloptychus petersi was identical to that reported in a North African snake, indicating that the same lineage is found in geographically distinct regions. By combining morphological and genetic information, Foleyella furcata (Linstow, 1899 filarial nematodes were identified in several Furcifer chameleons. This study provides insights into the distribution, diversity and host-parasite interactions of hemoparasites in wild reptile populations from Madagascar.

  12. Isospora plectrophenaxia n. sp (Apicomplexa : Eimeriidae), a new coccidian parasite found in Snow Bunting (Plectrophenax nivalis) nestlings on Spitsbergen

    NARCIS (Netherlands)

    Dolnik, Olga V.; Loonen, Maarten J. J. E.

    2007-01-01

    Faecal samples were collected from four 8 days old snow bunting nestlings from one nest in Ny-Aalesund, Spitsbergen, in summer 2006. After sporulation, samples were examined for coccidian parasites using flotation centrifuging. We found isosporan oocysts in three birds, intensity of infection varied

  13. Hemolivia mauritanica (Haemogregarinidae: Apicomplexa) infection in the tortoise Testudo graeca in the Near East with data on sporogonous development in the tick vector Hyalomna aegyptium

    OpenAIRE

    Paperna I.

    2006-01-01

    Testudo graeca tortoises were collected in the northern and southern Golan Heights (Israeli occupied territory of south Syria), and various locations in Israel and Palestine. Hyalomma aegyptium ticks were found only on Golan Height tortoises, and only the tortoises and ticks from the northern Golan Heights were infected with Hemolivia mauritanica. Tortoises became infected after ingesting infected ticks. Male ticks carrying sporocysts, which remain attached to tortoises for extended durations...

  14. Fylogeneze, diverzita, distribuce a hostitelská specifita parazitů Haemoproteus spp. (Apicomplexa: Haemosporida: Haemoproteidae) u suchozemských želv Palearktu.

    OpenAIRE

    MARŠÍKOVÁ, Aneta

    2016-01-01

    This study provides unique data on distribution, prevalence, host specificity, phylogeny, and intraspecific variability of two Haemoproteus species of Palearctic tortoises. Analyses based on cytochrome b sequences confirm the existence of two monophyletic lineages/species of Haemoproteus infecting Testudo tortoises. Microscopically, the species corresponding to H. anatolicum was revealed in blood smears of T. graeca, and H. caucasica was detected in two tortoise species, T. graeca and T. hors...

  15. Two new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from emerald tree skinks, Lamprolepis smaragdina (Lesson) (Sauria: Scincidae) from Papua New Guinea and the Philippines

    Science.gov (United States)

    McAllister, Chris T.; Seville, R. Scott; Duszynski, Donald W.; Bush, Sarah E.; Fisher, Robert N.; Austin, Christopher C.

    2013-01-01

    Two new species of Eimeria Schneider, 1875, from emerald tree skinks, Lamprolepis smaragdina (Lesson) are described from specimens collected in Papua New Guinea (PNG) and the Philippines. Oöcysts of Eimeria nuiailan n. sp. from the only L. smaragdina from PNG are ovoidal, with a smooth, colourless, bi-layered wall, measure 23.7 × 19.1 μm, and have a length/width (L/W) ratio of 1.3; both micropyle and oöcyst residuum are absent, but a fragmented polar granule is present. Sporocysts are ovoidal to ellipsoidal, 11.9 × 7.0 μm, L/W 1.7, and the wall is composed of two valves joined by a longitudinal suture; neither Stieda nor sub-Stieda bodies are present; a sporocyst residuum is present as a compact mass of granules. Sporozoites are elongate, 14.6 × 2.6 μm, and contain anterior and posterior refractile bodies with a nucleus between them. Oöcysts of Eimeria auffenbergi n. sp. from L. smaragdina collected in the Philippines are ovoidal, with a smooth, colourless, bi-layered wall, measure 19.9 × 15.8 μm, L/W 1.3; both micropyle and oöcyst residuum are absent, but one to four polar granules are present. Sporocysts are ovoidal to ellipsoidal, 10.3 × 5.8 μm, L/W 1.8, and the wall is composed of two valves joined by a longitudinal suture; neither Stieda nor sub-Stieda bodies are present; a sporocyst residuum is composed of dispersed granules.

  16. Morphological and molecular characterisation of Haemogregarina sp. (Apicomplexa: Adeleina: Haemogregarinidae) from the blood of the Caspian freshwater turtle Mauremys caspica (Gmelin) (Geoemydidae) in Iran.

    Science.gov (United States)

    Rakhshandehroo, Ehsan; Sharifiyazdi, Hassan; Ahmadi, Amin

    2016-06-01

    To date, a number of species of Haemogregarina have been described from different turtle hosts, mainly based on the morphology of the developmental stages detected in the host erythrocytes. The diversity and overlapping morphological features in the old and recent descriptions has led to considerable complications in the taxonomy of Haemogregarina spp. In this study, different stages of maturity and developing gamonts of a putative new species of Haemogregarina were detected in erythrocytes of the Caspian turtle Mauremys caspica (Gmelin) (Geoemydidae) originating from a southern province in Iran. Although some of the morphological characteristics were consistent with Haemogregarina stepanowi Danilewsky, 1885, some new observations were made, particularly in the gamont stage. The phylogenetic analysis based on 18S rDNA sequences revealed that the present isolate appears as basal to a large clade of Haemogregarina spp. with sequences available in the GenBank database. In accordance with the phylogenetic results, the present Iranian isolate showed a higher degree of interspecific divergence (up to 3.3%) compared to the data for the taxa available in the GenBank database. Thus, molecular data indicate that this isolate may represent a new species. However, further genetic analyses are needed as a complementary tool to the morphological characterisation in order to elucidate the phylogenetic relationships of Haemogregarina spp. PMID:27221004

  17. The Genus Cyclospora (Apicomplexa: Eimeriidae, with a description of Cyclospora schneideri n.sp. in the snake Anilius scytale scytale (Aniliidae from Amazonian Brazil: a review

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    Ralph Lainson

    2005-04-01

    Full Text Available A review is made of the recorded species of the coccidian genus Cyclospora and major events leading up to the discovery of C. cayetanensis, which is responsible for serious outbreaks of diarrhoea in man and is one of the aetiological agents of "traveller's diarrhoea". Humans appear to be the specific hosts, with the entire life-cycle in the intestine: to date there is no convincing evidence that the disease is a zoonosis. A description is given of oocysts and endogenous stages of C. schneideri n.sp., in the snake Anilius scytale scytale. Sporulation is exogenous and completed after about one week at 24-26º. Mature oocysts 19.8 × 16.6 (15.1 × 13.8-25.7 × 20.1, shape-index 1.2 (1.0-1.3: no oocyst residuum or polar bodies. Oocyst wall a single colourless, smooth layer with no micropyle: it is rapidly deformed or broken. Sporocysts 13.6 × 9.4 (11.3 × 8.3-15.1 × 9.9, shape-index 1.4 (1.2-1.5 with an inconspicuous Stieda body. Sporozoites 11-13 × 2.5-3. Endogenous stages are intracytoplasmic in the epithelial cells of the small intestine and with the characters of the Eimeriorina.

  18. Morphological and molecular characterization of Choleoeimeria pogonae n. sp. coccidian parasite (Apicomplexa: Eimeriidae, 1989, Paperna and Landsberg) in a western bearded dragon (Pogona minor minor).

    Science.gov (United States)

    Yang, Rongchang; Brice, Belinda; Ryan, Una

    2016-01-01

    A new species, Choleoeimeria pogonae n. sp. is described from a Western bearded dragon (Pogona minor minor) in Western Australia. Sporulated oocysts (n = 48) were cylindroidal in shape. Oocyst length, 27.0 (26.0-28.3) μm, oocyst width, 15.2 (14.0-16.5) μm, oocyst length/width ratio (L/W) 1.8 (1.6-1.9), each with 4 sporocysts (Eimeria-like) and a polar granule, but lacking a micropyle and oocyst residuum. Sporocysts are ovoidal in shape, sporocyst length, 10.0 (9.0-11.0) μm, sporocyst width 8.5 (7.0-9.5) μm, sporocyst L/W ratio, 1.2 (1.1-1.3). Stieda, substieda and parasubstieda bodies were all absent. Molecular analysis was conducted at the 18S rRNA and cytochrome c oxidase I (COI) loci. Phylogenetic analysis of 18S sequences revealed that C. pogonae n. sp. grouped together with another four Choleoeimeria spp. and exhibited 99.1%-99.4% genetic similarity. At the COI locus, C. pogonae n. sp. was in an independent clade and had the highest similarity (80.4%) to Eimeria cf. mivati from a chicken (Gallus gallus domesticus). According to the morphological and molecular data, this isolate is a new species of coccidian parasite. This study further supports the taxonomy of Choleoeimeria spp. as a new genus based on molecular phylogenetic analysis. PMID:26586629

  19. First report and description of a Cyrilia sp. (Apicomplexa: Haemogregarinidae) from a freshwater Cururu Stingray Potamotrygon cf. histrix (Elasmobranchii: Potamotrygonidae), from the Amazon Region, Brazil.

    Science.gov (United States)

    Magro, N M; de Oliveira, A T; O'Dwyer, L H

    2016-08-01

    A haemogregarine is described in 12 cururu stingray (Potamotrygon cf. histrix), from Mariuá Archipelago, Negro River, in the Brazilian Amazon Basin. All animals, both male and female, were parasitized by the haemogregarine and parasitaemia varied between 0.8% and 10% of erythrocytes. The stages observed included trophozoites or merozoites, suspected meronts, and gamonts presumed to be of two types, macrogamonts and microgamonts. Most stages were observed inside mature erythrocytes, while others were extracellular. The stages observed were most similar to those characteristics of the genus Cyrilia, than to any other fish haemogregarine and may represent a new Cyrilia species. PMID:26642832

  20. Clínica e hematologia de Bos indicus, Bos taurus e Bubalus bubalis inoculados com oocistos de Toxoplasma gondii (Apicomplexa: Toxoplasmatinae

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    Oliveira Francisco Carlos Rodrigues de

    2001-01-01

    Full Text Available Três animais de cada espécie (Bos indicus, Bos taurus e Bubalus bubalis foram inoculados, via oral, com 2,0 x 10(5 oocistos de Toxoplasma gondii. Seis outros animais, dois de cada espécie, foram mantidos como testemunhas. As alterações clínicas surgidas a partir do 3º dia após inoculação (DAI foram: hipertermia, taquicardia, taquipnéia, anorexia, prostração, corrimento nasal e lacrimejamento. Estes sinais foram mais evidentes nos taurinos, espécie que apresentou, ainda, diarréia, fotofobia e conjuntivite. Foi possível isolar T. gondii da corrente sangüínea em todas as espécies. Nos taurinos, a partir do 5º DAI até o final do experimento, o parasito foi isolado de todas as amostras de sangue colhidas semanalmente, com exceção do 14º, 35º e 63º DAI. Os bubalinos apresentaram parasitemia no 7º, 14º, 35º e 70º DAI e os zebuínos apenas no 7º e 28º DAI, correspondendo aos picos de temperatura, em todas as espécies, sendo mais evidente em taurinos. Os parâmetros clínico-laboratoriais demonstraram que os taurinos foram mais sensíveis ao T. gondii do que os zebuínos e estes não diferiram significativamente dos bubalinos, que tiveram aparente normalidade clínico-laboratorial.

  1. Morphological and molecular characterization of Choleoeimeria pogonae n. sp. coccidian parasite (Apicomplexa: Eimeriidae, 1989, Paperna and Landsberg) in a western bearded dragon (Pogona minor minor).

    Science.gov (United States)

    Yang, Rongchang; Brice, Belinda; Ryan, Una

    2016-01-01

    A new species, Choleoeimeria pogonae n. sp. is described from a Western bearded dragon (Pogona minor minor) in Western Australia. Sporulated oocysts (n = 48) were cylindroidal in shape. Oocyst length, 27.0 (26.0-28.3) μm, oocyst width, 15.2 (14.0-16.5) μm, oocyst length/width ratio (L/W) 1.8 (1.6-1.9), each with 4 sporocysts (Eimeria-like) and a polar granule, but lacking a micropyle and oocyst residuum. Sporocysts are ovoidal in shape, sporocyst length, 10.0 (9.0-11.0) μm, sporocyst width 8.5 (7.0-9.5) μm, sporocyst L/W ratio, 1.2 (1.1-1.3). Stieda, substieda and parasubstieda bodies were all absent. Molecular analysis was conducted at the 18S rRNA and cytochrome c oxidase I (COI) loci. Phylogenetic analysis of 18S sequences revealed that C. pogonae n. sp. grouped together with another four Choleoeimeria spp. and exhibited 99.1%-99.4% genetic similarity. At the COI locus, C. pogonae n. sp. was in an independent clade and had the highest similarity (80.4%) to Eimeria cf. mivati from a chicken (Gallus gallus domesticus). According to the morphological and molecular data, this isolate is a new species of coccidian parasite. This study further supports the taxonomy of Choleoeimeria spp. as a new genus based on molecular phylogenetic analysis.

  2. Molecular and phylogenetic characterizations of an Eimeria krijgsmanni Yakimoff & Gouseff, 1938 (Apicomplexa: Eimeriidae) mouse intestinal protozoan parasite by partial 18S ribosomal RNA gene sequence analysis.

    Science.gov (United States)

    Takeo, Toshinori; Tanaka, Tetsuya; Matsubayashi, Makoto; Maeda, Hiroki; Kusakisako, Kodai; Matsui, Toshihiro; Mochizuki, Masami; Matsuo, Tomohide

    2014-08-01

    Previously, we characterized an undocumented strain of Eimeria krijgsmanni by morphological and biological features. Here, we present a detailed molecular phylogenetic analysis of this organism. Namely, 18S ribosomal RNA gene (rDNA) sequences of E. krijgsmanni were analyzed to incorporate this species into a comprehensive Eimeria phylogeny. As a result, partial 18S rDNA sequence from E. krijgsmanni was successfully determined, and two different types, Type A and Type B, that differed by 1 base pair were identified. E. krijgsmanni was originally isolated from a single oocyst, and thus the result show that the two types might have allelic sequence heterogeneity in the 18S rDNA. Based on phylogenetic analyses, the two types of E. krijgsmanni 18S rDNA formed one of two clades among murine Eimeria spp.; these Eimeria clades reflected morphological similarity among the Eimeria spp. This is the third molecular phylogenetic characterization of a murine Eimeria spp. in addition to E. falciformis and E. papillata.

  3. Hemolivia mauritanica (Haemogregarinidae: Apicomplexa infection in the tortoise Testudo graeca in the Near East with data on sporogonous development in the tick vector Hyalomna aegyptium

    Directory of Open Access Journals (Sweden)

    Paperna I.

    2006-12-01

    Full Text Available Testudo graeca tortoises were collected in the northern and southern Golan Heights (Israeli occupied territory of south Syria, and various locations in Israel and Palestine. Hyalomma aegyptium ticks were found only on Golan Height tortoises, and only the tortoises and ticks from the northern Golan Heights were infected with Hemolivia mauritanica. Tortoises became infected after ingesting infected ticks. Male ticks carrying sporocysts, which remain attached to tortoises for extended durations, apparently served as the source for dissemination of new infections among tortoises. Sporogenesis followed the pattern observed in the two other known species of Hemolivia, though there was some evident variation in fine-structural detail. The sutural slit detected in the H. mauritanica mature sporocyst wall was reminiscent of the suture characteristic of Coccidia of heterothermic vertebrate hosts; it could be a common ancestral character for both hemogregarines and Coccidia.

  4. Intestinal Coccidia (Apicomplexa: Eimeriidae of Brazilian Lizards. Eimeria carmelinoi n.sp., from Kentropyx calcarata and Acroeimeria paraensis n.sp. from Cnemidophorus lemniscatus lemniscatus (Lacertilia: Teiidae

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    Lainson Ralph

    2002-01-01

    Full Text Available Eimeria carmelinoi n.sp., is described in the teiid lizard Kentropyx calcarata Spix, 1825 from north Brazil. Oocysts subspherical to spherical, averaging 21.25 x 20.15 µm. Oocyst wall smooth, colourless and devoid of striae or micropyle. No polar body or conspicuous oocystic residuum, but frequently a small number of fine granules in Brownian movement. Sporocysts, averaging 10.1 x 9 µm, are without a Stieda body. Endogenous stages characteristic of the genus: intra-cytoplasmic, within the epithelial cells of the ileum and above the host cell nucleus. A re-description is given of a parasite previously described as Eimeria cnemidophori, in the teiid lizard Cnemidophorus lemniscatus lemniscatus. A study of the endogenous stages in the ileum necessitates renaming this coccidian as Acroeimeria cnemidophori (Carini, 1941 nov.comb., and suggests that Acroeimeria pintoi Lainson & Paperna, 1999 in the teiid Ameiva ameiva is a synonym of A. cnemidophori. A further intestinal coccidian, Acroeimeria paraensis n.sp. is described in C. l. lemniscatus, frequently as a mixed infection with A. cnemidophori. Mature oocysts, averaging 24.4 x 21.8 µm, have a single-layered, smooth, colourless wall with no micropyle or striae. No polar body, but the frequent presence of a small number of fine granules exhibiting Brownian movements. Sporocysts 9 x 8, without a Stieda body. Endogenous stages epicytoplasmic, characteristic of the genus, in the upper ileum. The importance of a study of the endogenous stages of eimeriid coccidia is discussed.

  5. Description of the Oocysts of Three New Species of Eimeria (Apicomplexa: Eimeriidae from Iguanid Lizards (Sauria: Iguanidae of Central and South America

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    Daszak P

    1998-01-01

    Full Text Available Three new species of Eimeria are described from iguanid lizards of Central and South America. The oocysts of each species have no micropyles or residua and the sporocysts lack Stieda bodies, but all have a sporocyst residuum. Eimeria sanctaluciae n.sp. was found in the St. Lucia tree lizard, Anolis luciae, collected from the Maria Islands, Lesser Antilles. The oocysts are spherical to subspherical, averaging 17.3 x 16.5 µm, with a single layered colourless wall; about 60% contain polar granules. The sporocysts are ellipsoidal and average 7.7 x 5.5 µm. Eimeria liolaemi n.sp. was recovered from the blue-gold swift, Liolaemus taenius, from Chile. The oocysts are spherical to subspherical, measuring 21 x 20.1 µm with a single-layered colourless wall. The sporocysts are subspherical and average 7.4 x 6.8 µm. Eimeria caesicia n.sp. is described from the Brazilian collared iguanid, Tropidurus torquatus. The oocysts measure 27.4 x 23.7 µm, are spherical to subspherical, with a bilayered wall, the outer surface of which appears pale blue in colour, the thin, inner wall appearing brown, when viewed by direct light under the optical microscope. The sporocysts are subspherical and average 9.4 x 7.2 µm. Unnamed polysporocystid oocysts with dizoic sporocysts are reported from the faeces of the lesser St. Vincent tree lizard, Anolis trinitatis and the possibility of spurious parasitism briefly discussed. In addition, oocysts of an unnamed Isospora sp. with a smooth oocyst wall which closely resembles I. reui were recovered from A. trinitatis.

  6. Description of Pythonella scleruri n. sp. (Apicomplexa: Eimeriidae from a Brazilian Bird Rufous-Breasted-Leaftosser Sclerurus scansor, 1835 (Passeriformes: Furnariidae

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    Kawazoe Urara

    1999-01-01

    Full Text Available Coccidian oocysts containing 16 sporocysts with 4 sporozoites in each were observed in a faecal sample from Sclerurus scansor collected in the Itatiaia National Park, southeastern region of Brazil. The oocysts are characterized by ellipsoidal shape measuring 42.5 x 32.8 mm, with smooth, thick double-layered wall of a greenish-orange colour. An oocyst residuum of numerous scattered granules among the sporocysts in sporulated ones; 16 round sporocysts, averaging 10.5 x 10 mm each containing four elongated sporozoites; presence of residuum; absence of Stieda body. The presently described coccidian, recorded for the first time in birds, is a new species named P. scleruri.

  7. First report and description of a Cyrilia sp. (Apicomplexa: Haemogregarinidae) from a freshwater Cururu Stingray Potamotrygon cf. histrix (Elasmobranchii: Potamotrygonidae), from the Amazon Region, Brazil.

    Science.gov (United States)

    Magro, N M; de Oliveira, A T; O'Dwyer, L H

    2016-08-01

    A haemogregarine is described in 12 cururu stingray (Potamotrygon cf. histrix), from Mariuá Archipelago, Negro River, in the Brazilian Amazon Basin. All animals, both male and female, were parasitized by the haemogregarine and parasitaemia varied between 0.8% and 10% of erythrocytes. The stages observed included trophozoites or merozoites, suspected meronts, and gamonts presumed to be of two types, macrogamonts and microgamonts. Most stages were observed inside mature erythrocytes, while others were extracellular. The stages observed were most similar to those characteristics of the genus Cyrilia, than to any other fish haemogregarine and may represent a new Cyrilia species.

  8. Redescription of Haemogregarina garnhami (Apicomplexa: Adeleorina) from the blood of Psammophis schokari (Serpentes: Colubridae) as Hepatozoon garnhami n. comb. based on molecular, morphometric and morphologic characters.

    Science.gov (United States)

    Abdel-Baki, Abdel-Azeem S; Al-Quraishy, Saleh; Zhang, J Y

    2014-06-01

    Hepatozoon garnhami n. comb. was redescribed from Schokari sand snakes (Psammophis schokari) collected from Riyadh city in Saudi Arabia. Gametocytes were found in the peripheral blood of 2 of 15 snakes examined. Based on the similar morphological and morphometric characteristics, the same host and a similar host habitat environment, it can be concluded for the first time that the present species is conspecific with Haemogregarina garnhami previously reported from Psammophis shokari aegyptius. To further characterize this parasite, the partial 18S rRNA gene was amplified and sequenced. The sequence analysis also showed that Haemogregarina garnhami should be reassigned into the genus Hepatozoon as Hepatozoon garnhami which has 99.5% (859/863 bp) sequence similarity to Hepatozoon ayorgbor, infecting the erythrocytes of Python regius in Ghana. Phylogenetic analysis showed that H. garnhami formed a mixed clade with Hepatozoon spp. from geckos, snakes and rodents and ophidian Hepatozoon spp. did not form a separated phylogenetic unit. Also, Psammophis schokari-infecting Hepatozoon contained several different genetic lineages. To our knowledge, the present work extends the geographic distribution of H. garnhami and is the first report of Hepatozoon infection in snakes from Saudi Arabia.

  9. Coccidial dispersion across New World marsupials: Klossiella tejerai Scorza, Torrealba & Dagert, 1957 (Apicomplexa: Adeleorina) from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) (Mammalia: Didelphimorphia).

    Science.gov (United States)

    Dos Santos, Caroline Spitz; Berto, Bruno Pereira; do Bomfim Lopes, Bruno; Cordeiro, Matheus Dias; da Fonseca, Adivaldo Henrique; Filho, Walter Leira Teixeira; Lopes, Carlos Wilson Gomes

    2014-09-01

    Klossiella tejerai Scorza, Torrealba & Dagert, 1957 is a primitive coccidian parasite reported from the New World marsupials Didelphis marsupialis (Linnaeus) and Marmosa demerarae (Thomas). The current work describes K. tejerai from the Brazilian common opossum Didelphis aurita (Wied-Neuwied) in Southeastern Brazil, evidencing the coccidial dispersion across opossums of the same family. The sporocysts recovered from urine samples were ellipsoidal, 20.4 × 12.7 µm, with sporocyst residuum composed of scattered spherules and c.13 sporozoites per sporocyst, with refractile bodies and nucleus. Macrogametes, microgametes, sporonts, sporoblasts/sporocysts were identified within parasitophorous vacuoles of epithelial cells located near the renal corticomedullary junction. Didelphis marsupialis should not have transmitted K. tejerai to D. aurita because they are not sympatric; however M. demerarae is sympatric with D. marsupialis and D. aurita. Therefore, D. aurita becomes the third host species for K. tejerai in South America. PMID:25079818

  10. Two new species of coccidia (Apicomplexa: Eimeriidae) from leaf-tailed geckos, Uroplatus spp. (Sauria: Gekkonidae) from Madagascar, including a new host of Eimeria brygooi Upton & Barnard, 1987.

    Science.gov (United States)

    McAllister, Chris T; Scott Seville, R; Hartdegen, Ruston

    2016-10-01

    During May and June 2015, four common leaf-tailed geckos, Uroplatus fimbriatus (Schneider), five satanic leaf-tailed geckos, Uroplatus phantasticus (Boulenger), and four mossy leaf-tailed geckos, Uroplatus sikorae Boettger originally collected from Madagascar and housed at the Dallas Zoo, USA, had their faeces examined for coccidian parasites. Eight (62%) geckos were found to be passing oöcysts, including a new eimerian, a new isosporan and a previously described eimerian. Three of four (75%) U. fimbratus (type-host) and one of five (20%) U. phantasticus were infected with Eimeria schneideri n. sp.; oöcysts were subspheroidal to ellipsoidal with a bi-layered wall and measured (mean length × width, L × W) 15.1 × 13.5 µm, with a length/width (L/W) ratio of 1.1. A micropyle and oöcyst residuum were absent but one to many polar granules were present. Sporocysts were ovoidal, 6.9 × 5.3 µm, L/W = 1.3. Stieda, sub-Stieda and para-Stieda bodies were absent. A globular sporocyst residuum was present as dispersed granules. Four of five (80%) U. phantasticus harboured Isospora boulengeri n. sp.; oöcysts were subpheroidal to ellipsoidal with a bi-layered wall and measured 17.3 × 16.0 µm, L/W = 1.1. A micropyle and oöcyst residuum were absent but a polar granule was present. Sporocysts were ellipsoidal, 9.5 × 6.9 µm, L/W = 1.4. Stieda and sub-Stieda bodies were present but a para-Stieda body was absent. A globular sporocyst residuum was present with dispersed granules. In addition, one of four (25%) U. sikorae was infected with an eimerian indistinguishable from Eimeria brygooi Upton & Barnard, 1987, previously reported from Madagascar day gecko, Phelsuma grandis Gray and golddust day gecko, Phelsuma laticauda (Boettger) from Madagascar. These are the first coccidians described from Uroplatus spp. PMID:27638735

  11. Mattesia weiseri sp. nov., a new neogregarine (Apicomplexa: Lipotrophidae) pathogen of the great spruce bark beetle, Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae).

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    Yaman, Mustafa; Radek, Renate

    2015-08-01

    A new neogregarine pathogen of the great spruce bark beetle, Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae), is described based on light microscopy and ultrastructural characteristics. The pathogen infects the fat body and the hemolymph of the beetle. The infection was nonsynchronous so that different developmental stages could be observed simultaneously in the hemolymph. All life stages from sporozoite to oocyst of the pathogen including micronuclear and macronuclear merozoites were detected. The sporozoites measured about 8.7 × 1.9 μm and trophozoites, 11.9 × 3.3 μm. Micronuclear merozoites seen in the hemolymph were motile, elongate, slightly broader at the anterior pole, and measured 18.4 × 2.0 μm. Macronuclear merozoites had a size of ca. 16.4 × 2.3 μm. Gametogamy results in the formation of two paired oocysts within a gametocyst. The lemon-shaped oocyst measured 10.9 × 6.1 μm and had a very thick wall (375-450 nm). All morphological and ultrastructural characteristics of the life cycle stages indicate that the described neogregarine in D. micans is clearly different from known Mattesia species infecting bark beetles, and from any other described Mattesia spp. Therefore, we create a new species, Mattesia weiseri sp. nov.

  12. Morphological and molecular characterization of Eimeria labbeana-like (Apicomplexa:Eimeriidae) in a domestic pigeon (Columba livia domestica, Gmelin, 1789) in Australia.

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    Yang, Rongchang; Brice, Belinda; Elloit, Aileen; Ryan, Una

    2016-07-01

    An Eimeria species is described from a domestic pigeon (Columba livia domestica). Sporulated oocysts (n = 35) were subspherical, with a smooth bi-layered oocyst wall (1.0 μm thick). Oocysts measured 20.2 × 16.1 (22.0-18.9 × 15.7-18.9) μm, oocyst length/width (L/W) ratio, 1.38. Oocyst residuum and a polar granule were present. The micropyle was absent. Sporocysts are elongate-ovoid, 13.0 × 6.1 (14.5-12.5 × 5.5-7.0) μm, sporocyst L/W ratio, 2.13 (2.0-2.2), sporocyst residuum was present, composed of numerous granules in a spherical or ovoid mass. Each sporocyst contained 2 banana-shaped sporozoites, 12.3 × 3.5 (11.8-13.0 × 3.3-3.6) μm. A spherical-ellipsoid posterior refractile body was found in the sporozoites. A nucleus was located immediately anterior to the posterior refractile body. Molecular analysis was conducted at three loci; the 18S and 28S ribosomal RNA genes and the mitochondrial cytochrome oxidase gene (COI). At the 18S locus, the new isolate shared 98.0% genetic similarity with three Isospora isolates from Japan from the domestic pigeon (Columba livia domestica). At the 28S locus, it grouped separately and shared 92.4% and 92.5% genetic similarity with Isospora anthochaerae (KF766053) from a red wattlebird (Anthochaera carunculata) from Australia and an Isospora sp. (MS-2003 - AY283845) from a Himalayan grey-headed bullfinch (Pyrrhula erythaca) respectively. At COI locus, this new isolate was in a separate clade and shared 95.6% and 90.0% similarity respectively with Eimeria tiliquae n. sp. from a shingleback skink in Australia and an Eimeria sp. from a common pheasant (Phasianus colchicus) from America. Based on the morphological data, this isolate is most similar to Eimeria labbeana. As no molecular data for E. labbeana is available and previous morphological data is incomplete, we refer to the current isolate as E. labbeana-like.

  13. Morphological and molecular characterization of Eimeria purpureicephali n. sp. (Apicomplexa:Eimeriidae) in a red-capped parrot (Purpureicephalus spurius, Kuhl, 1820) in Western Australia

    Science.gov (United States)

    Yang, Rongchang; Brice, Belinda; Ryan, Una

    2016-01-01

    A new Eimeria species is described from a red-capped parrot (Purpureicephalus spurius). Sporulated oocysts (n = 31) were spherical to subspherical, with a rough bilayered oocyst wall 0.8 μm thick. Oocysts measured 24.0 × 22.8 (20.4–26.4 × 18.3–25.9) μm, oocyst length/width ratio, 1.10. Oocyst residuum, polar granule and micropyle were absent. Sporocysts are elongate-ovoid, 11.0 × 7.3 (12.7–9.2 × 7.9–6.6) μm, sporocyst length/width ratio, 1.51 (1.33–1.71). The thin convex Stieda body and indistinct substieda bodies were present and the sporocyst residuum was composed of numerous small granules less than 1.0 μm in diameter dispersed randomly. Each sporocyst contained 2 sausage-shaped sporozoites in head-to-tail arrangement. The sporozoite nuclei were located centrally surrounded by refractile bodies. Molecular analysis was conducted at two loci; the 18S ribosomal RNA gene and the cytochrome c oxidase subunit I gene. At the18S locus, the new isolate shared 99.0% genetic similarity with Eimeria dispersa and Eimeria innocua from the turkey. At the cytochrome c oxidase subunit I gene locus, this new isolate was most closely related to E. dispersa and E. innocua, presented 99.0% and 98.0% genetic similarity, respectively. This new isolate and E. dispersa grouped together in the same clade. Based on the morphological and molecular data, this isolate is a new species of coccidian parasite, which is named Eimeria purpureicephali n. sp. after its host, the red-capped parrot (Purpureicephalus spurius). PMID:26977403

  14. Intestinal coccidia (Apicomplexa: Eimeriidae) of Brazilian lizards. Eimeria carmelinoi n.sp., from Kentropyx calcarata and Acroeimeria paraensis n.sp. from Cnemidophorus lemniscatus lemniscatus (Lacertilia: Teiidae).

    Science.gov (United States)

    Lainson, Ralph

    2002-03-01

    Eimeria carmelinoi n.sp., is described in the teiid lizard Kentropyx calcarata Spix, 1825 from north Brazil. Oocysts subspherical to spherical, averaging 21.25 x 20.15 micro m. Oocyst wall smooth, colourless and devoid of striae or micropyle. No polar body or conspicuous oocystic residuum, but frequently a small number of fine granules in Brownian movement. Sporocysts, averaging 10.1 x 9 microm, are without a Stieda body. Endogenous stages characteristic of the genus: intra-cytoplasmic, within the epithelial cells of the ileum and above the host cell nucleus. A re-description is given of a parasite previously described as Eimeria cnemidophori, in the teiid lizard Cnemidophorus lemniscatus lemniscatus. A study of the endogenous stages in the ileum necessitates renaming this coccidian as Acroeimeria cnemidophori (Carini, 1941) nov.comb., and suggests that Acroeimeria pintoi Lainson & Paperna, 1999 in the teiid Ameiva ameiva is a synonym of A. cnemidophori. A further intestinal coccidian, Acroeimeria paraensis n.sp. is described in C. l. lemniscatus, frequently as a mixed infection with A. cnemidophori. Mature oocysts, averaging 24.4 x 21.8 microm, have a single-layered, smooth, colourless wall with no micropyle or striae. No polar body, but the frequent presence of a small number of fine granules exhibiting Brownian movements. Sporocysts 9 x 8, without a Stieda body. Endogenous stages epicytoplasmic, characteristic of the genus, in the upper ileum. The importance of a study of the endogenous stages of eimeriid coccidia is discussed. PMID:12016449

  15. Sarcocystis caninum and Sarcocystis svanai n. spp. (Apicomplexa: Sarcocystidae) Associated with Severe Myositis and Hepatitis in the Domestic Dog (Canis familiaris).

    Science.gov (United States)

    Dubey, Jitender P; Sykes, Jane E; Shelton, G Diane; Sharp, Nick; Verma, Shiv K; Calero-Bernal, Rafael; Viviano, Jenifer; Sundar, Natarajan; Khan, Asis; Grigg, Michael E

    2015-01-01

    There are several reports of Sarcocystis sarcocysts in muscles of dogs, but these species have not been named. Additionally, there are two reports of Sarcocystis neurona in dogs. Here, we propose two new names, Sarcocystis caninum, and Sarcocystis svanai for sarcocysts associated with clinical muscular sarcocystosis in four domestic dogs (Canis familiaris), one each from Montana and Colorado in the USA, and two from British Columbia, Canada. Only the sarcocyst stage was identified. Most of the sarcocysts identified were S. caninum. Sarcocysts were studied using light microscopy, transmission electron microscopy (TEM), and polymerase chain reaction. Based on collective results two new species, S. caninum and S. svanai were designated. Sarcocystis caninum and S. svanai were structurally distinct. Sarcocystis caninum sarcocysts were up to 1.2 mm long and up to 75 μm wide. By light microscopy, the sarcocyst wall was relatively thin and smooth. By TEM, the sarcocyst wall was "type 9", 1-2 μm thick, and contained villar protrusions that lacked microtubules. Bradyzoites in sections were 7-9 μm long. Sarcocysts of S. svanai were few and were identified by TEM. Sarcocystis svanai sarcocysts were "type 1", thin walled (< 0.5 μm), and the wall lacked villar protrusions but had tiny blebs that did not invaginate. DNA was extracted either from infected frozen muscle biopsies or formalin-fixed paraffin-embedded sections. Dogs were either singly infected with S. caninum or multiply co-infected with S. caninum and S. svanai (the result of a mixed infection) based on multilocus DNA sequencing and morphology. BLASTn analysis established that the sarcocysts identified in these dogs were similar to, but not identical to Sarcocystis canis or Sarcocystis arctosi, parasites found to infect polar bears (Ursus maritimus) or brown bears (Ursus arctosi), respectively. However, the S. caninum sequence showed 100% identify over the 18S rRNA region sequenced to that of S. arctica, a parasite known to infect Arctic foxes (Vulpes lagopus). PMID:25256157

  16. Seven new species of Eimeria Schneider, 1875 (Apicomplexa: Eimeriidae) from colubrid snakes of Guatemala and a discussion of what to call ellipsoid tetrasporocystic, dizoic coccidia of reptiles.

    Science.gov (United States)

    Asmundsson, I M; Duszynski, D W; Campbell, J A

    2006-06-01

    During a survey of Guatemalan herpetofauna in the summers of 1998-2000, 29 presumed new species of Eimeria Schneider, 1875 were found, seven of which have a distinct elongate-ellipsoidal shape (L/W ratio >or= 1.7) and are described herein. Six of the seven new species are similar in oöcyst length, width and L/W ratio and sporocyst length, width and L/W ratio, lack a micropyle, oöcyst residuum, Stieda body, sub-- and parastieda bodies, have a polar granule and sporocyst residuum, and their sporocysts appear to have dehiscence sutures. The seventh is slightly smaller and has sporocysts with a Stieda body. The new species are: E. coniophanes n. sp - whose sporulated oöcysts from Coniophanes fissidens are 29.2x14.9 (27-31x13-16) microm, with sporocysts 10.0 x 7.8 microm; E. coniophis n. sp. -from Conophis lineatus are 32.0x16.5 (30-34x14-18) microm, with sporocysts 10.2 x 8.9microm; E. dryomarchoni n. sp. - from Drymarchon corais are 32.2x17.7 (31-34x17-19) microm, with sporocysts 10.7 x 8.6 microm; E. leptophis n. sp. - from Leptophis mexicanus are 29.5x17.0 (28-31x16-18) microm, with sporocysts 10.0 x 9.1 microm; E. oxybelis n. sp. - from Oxybelis aeneus are 31.8x16.5 (29-33x15-18) microm, with sporocysts 10.3 x 8.8 microm; and E. scaphiodontophis n. sp. - from Scaphiodontophis annulatus are 30.0x15.3 (28-33x14-16) microm, with sporocysts 9.9 x 7.9 microm. Sporulated oöcysts of E. siboni n. sp. from Sibon nebulata are 24.3x14.2 (21-27x13-16) microm, with sporocysts 10.0 x 7.1 microm and with a Stieda body. We conclude that until all aspects of each life-cycle are known, it is prudent at this time to name all tetrasporocystic dizoic coccidia from snakes as members of Eimeria rather than place some of them in Choleoeimeria Paperna & Landsberg, 1989.

  17. Oocyst shedding by green-winged-saltator (Saltator similis in the diagnostic of coccidiosis and Isospora similisi n. sp. (Apicomplexa: Eimeriidae Eliminação de oocistos por trinca-ferro-verdadeiro (Saltator similis no diagnóstico da coccidiose e Isospora similisi n. sp. (Apicomplexa: Eimeriidae

    Directory of Open Access Journals (Sweden)

    Cleide Domingues Coelho

    2013-03-01

    Full Text Available Diurnal periodicity is a phenomenon that has been observed in coccidian of Isospora parasites of passerines, which have been eliminated great number of oocysts at dusk. The objective of this study was to evaluate the occurrence of periodicity of oocysts presence in the green-winged-saltator Saltator similis, and its use in the diagnosis of coccidiosis in wild birds in captivity. A total of 220 fecal samples were collected from birds, apprehended from illegal trading and kept in quarantine in CETAS∕IBAMA, in the morning and late afternoon, from May to November 2010. It was observed that 1.82% of the samples collected in the morning were positive, while 31.36% of samples were positive in the late afternoon. In addition, the number of oocysts shed was greater in the afternoon. Therefore, it was concluded that the sampling in the late afternoon provided greater reliability for the diagnosis of coccidiosis in green-winged-saltators. Moreover, in this study a new isosporoid coccidian parasite from the green-winged-saltator S. similis was observed and is herein described. Isospora similisi n. sp. oocysts are spheroidal to sub-spheroidal, 27.5 × 25.9 µm, with a smooth and bi-layered wall, ∼1.2 mm. Micropyle and oocyst residuum are absent, but splinter-like or comma-like granules are present. Sporocysts are ellipsoidal or slightly ovoidal, 17.4 × 12.2 mm. A stieda body and substieda body are present. The sporocyst residuum is composed of granules of different sizes. Sporozoites are vermiform with a single refractile body and a nucleus. This is the fourth description of an isosporoid coccidium infecting S. similis and the sixth description from Cardinalidae.A periodicidade diurna é um fenômeno que tem sido observado em coccídios do gênero Isospora parasitas de pássaros, os quais eliminam uma maior quantidade de oocistos ao entardecer. O objetivo deste estudo foi determinar a periodicidade de eliminação de oocistos pelas fezes no trinca-ferro-verdadeiro Saltator similis, e sua utilização no diagnóstico da coccidiose. Foram colhidas 220 amostras fecais de aves oriundas de apreensões do tráfico de animais silvestres e mantidas na quarentena do CETAS∕IBAMA, nos períodos da manhã e ao entardecer, de maio a novembro de 2010. Observou-se que 1,82% das amostras colhidas no período da manhã foram positivas, enquanto que 31,36% das amostras colhidas foram positivas ao entardecer, onde o maior número de oocistos foi observado no período da tarde. Portanto, concluiu-se que a colheita de amostras ao entardecer oferece maior confiabilidade para o diagnóstico da coccidiose. Além disso, descreve-se um novo coccídio do trinca-ferro-verdadeiro S. similis. Isospora similisi n. sp. possui oocistos esféricos a subesféricos, 27,5 × 25,9 µm, com parede dupla e lisa, ∼1,2 µm. A micrópila e o resíduo do oocisto estão ausentes, porém pequenos grânulos estão presentes. Os esporocistos são elipsóides ou levemente ovóides, 17,4 × 12,2 µm. Os corpos de Stieda e substieda estão presentes. O resíduo do esporocisto está presente e os esporozoítos possuem um corpo refrátil posterior e um núcleo. Esta é a quarta espécie isosporóide descrita de S. similis e a sexta descrição na família Cardinalidae.

  18. Systemic inflammatory response indicators in rabbits (Oryctolagus cuniculus experimentally infected with sporulated oocysts of Eimeria stiedai (Apicomplexa: Eimeriidae Indicadores da resposta inflamatória sistêmica em coelhos (Oryctolagus cuniculus infectados experimentalmente com oocistos esporulados de Eimeria stiedai (Apicomplexa: Eimeriidae

    Directory of Open Access Journals (Sweden)

    Fagner Luiz da Costa Freitas

    2011-06-01

    Full Text Available Hemograms and acute-phase proteins in adult male New Zealand White rabbits that had been experimentally infected orally with sporulated oocysts of Eimeria stiedai were evaluated over a 28-day period. Fifty animals were used, divided into two groups: group A infected with 1 × 10(4 sporulated oocysts of E. stiedai and group B inoculated with distilled water. On the seventh day after infection, the infected animals presented anemia and leukocytosis with neutrophilia and monocytosis. Protein fractionation by means of electrophoresis identified 19 acute-phase proteins with molecular weights ranging from 24 to 238 kD. Ceruloplasmin, transferrin and haptoglobin showed high levels on the seventh day after infection, with gradual increases in their concentrations until the end of the experimental period. Thus, from the data of the present study, E. stiedai is considered to be a pyogenic etiological agent for which the infection level can be monitored through the leukocyte count and serum concentrations of ceruloplasmin, transferrin and haptoglobin, and these can be recommended as complementary tests.O hemograma e proteínas de fase aguda foram avaliados durante 28 dias em coelhos adultos, machos, raça branco Nova Zelândia, infectados experimentalmente, via oral, com oocistos esporulados de Eimeria stiedai. Foram usados 50 animais distribuídos em dois grupos: grupo A infectado com 1 × 10(4 oocistos esporulados de E. stiedai e grupo B inoculado com água destilada. No 7º dia após a infecção (dpi, os animais infectados tiveram anemia, leucocitose com neutrofilia e monocitose. O método de fracionamento de proteínas por eletroforese identificou 19 proteínas de fase aguda com pesos moleculares que variaram entre 24 e 238 kD. A ceruloplasmina, transferrina e haptoglobina tiveram níveis elevados no 7° dpi com aumento progressivo de suas concentrações até o término do período experimental. Desta forma, considerando-se os dados encontrados no presente estudo, E. stiedai é considerado um agente etiológico piogênico que pode ter sua infecção monitorada por determinação do leucograma e das concentrações séricas de ceruloplasmina, transferrina e haptoglobina, podendo ser estes recomendados como exames complementares.

  19. Elongation Factor-1a is a novel protein associated with host cell invasion and a potential protective antigen of Cryptosporidium parvum*

    Science.gov (United States)

    The phylum Apicomplexa comprises obligate intracellular parasites that infect vertebrates. All invasive forms of Apicomplexa possess a unique complex of organelles at the anterior end, referred to as the apical complex, which is involved in host cell invasion. Previously, we generated the chicken m...

  20. 顶复门原虫类异戊二烯生物合成途径及其关键酶的研究进展%Advance in Isoprenoids Biosynthesis Pathway and DOXP Reductoisomerase in Apicomplexa

    Institute of Scientific and Technical Information of China (English)

    廖申权; 吴彩艳; 戚南山; 吕敏娜; 覃宗华; 孙铭飞

    2012-01-01

    顶复门原虫包括疟原虫(Plasmodium spp.)、刚地弓形虫(Toxoplasma gondii)、艾美耳球虫(Eimeria spp.)、锥虫(Trypanosoma spp.)、泰勒虫(Theileria spp.)及巴贝斯虫(Babesia spp.)等一大类引起严重人畜疾病的寄生性原虫.顶复门原虫利用2C-甲基-D-赤藓糖醇-4-磷酸(MEP)途径合成类异戊二烯前体物质,这些化合物对于维持顶复门原虫的生存具有十分重要的作用.1-脱氧-D-木酮糖-5-磷酸(DOXP)还原异构酶是MEP途径的关键酶,对其作用机理及抑制剂的筛选研究已取得重要进展.论文对顶复门原虫类异戊二烯的MEP途径,DOXP还原异构酶的作用机理及靶标研究进展进行综述.

  1. FIMERIA CHEVRIERI SP. NOV. (APICOMPLEXA, EIMERIIDAE) FROM APODEMUS CHEVRIERI (RODENTIA, MURIDAE)%高原姬鼠一新艾美球虫记述(顶复合门,艾美球虫科)

    Institute of Scientific and Technical Information of China (English)

    胡俊杰; 谢昆; 左仰贤

    2008-01-01

    Fresh fecal samples from 31 Apodemus chevrieri M-Edwards 1868 were collected and examined for coccidian in 2006. The mice were collected in Taiping Town. Nine of the 31 (29%) specimens of mice contained two spedes of genus Eimeria. One of thern is described as new species. Sporulated oocysts of Eimeria chevrieri sp. nov. were ellipsoidal, 21.2× 16.3 (22.2-19.7 × 17.3-15.6) μm, with ovoid sporocysts, 11.2×7.5 (12.3-10.3x8.3-6.8) μm. The smooth oocysts wall had one layer arotmd 1.0μm thick. No micropyle and oocyst residuum were present, but 1-2 polar granules, sporocyst residuum, sdeda body and sub-sdeda body were present.%粪检云南省昆明市太平镇捕获的31只高原姬鼠Apodemus chevrieri,在9只高原姬鼠中共发现了2种艾美球虫,自然感染率为29%,其中1种被命名为新种:齐氏艾美球虫Eimeria chevrieri sp.nov..齐氏艾美球虫孢子化的卵囊椭圆形,大,J、为21.2μm×16.3 μm(22.2~19.7 μm×17.3~15.6/μm).卵囊壁光滑,单层,厚约1.0 μm;无胚孔和卵囊余体.有1~2个极体,极体形状不规则,直径1.0~2.0μm.卵圆形的孢子囊大小为11.2 μm ×7.5μm(12.3~10.3 μm×8.3~6.8μm),有孢子囊余体,且主要分布在2个子孢子的中间,斯氏体扁豆形,大小为1.0μm×0.3μm,亚斯氏体亚球形,大小为2.5μm ×1.5 μm.子孢子在孢子囊里面头尾相接,在其宽端有1个明显的反光体,直径约3 μm.模式标本保存在云南大学标本馆.

  2. Description of Eimeria motelo sp. n. (Apicomplexa: Eimeriidae from the yellow footed tortoise, Geochelone denticulata (Chelonia: Testudinidae, and replacement of Eimeria carinii Lainson, Costa & Shaw, 1990 by Eimeria lainsoni nom. nov.

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    Lada Hurková

    2000-12-01

    Full Text Available Eimeria motelo sp. n. is described from faeces of the yellow-footed tortoise, Geochelone denticulata (L.. Oocysts are irregularly ellipsoidal or cylindrical, with slightly expressed lobed protrusions and irregularities at the poles, possibly caused by wrinkling of the oocyst wall, 17 (15-19 × 9.4 (8.5-11 µm, shape index (length/width being 1.81 (1.45-2. The oocyst wall is smooth, single-layered, 0.5 µm thick with no micropyle. There are no polar bodies. Sporocysts are ellipsoidal, 8.9 (7.5-10 × 4.4 (4-5 µm, shape index 2.03 (1.7-2.5. A sporocyst residuum is present, composed of many granules of irregular size. The sporozoites are elongate, lying lengthwise in the sporocysts. Comparison with other species of the genus Eimeria parasitising members of family Testudinidae indicates that the presently described coccidium represents a new species. The name of Eimeria carinii Lainson, Costa & Shaw, 1990 is found to be preoccupied by a homonym, Eimeria carinii Pinto 1928 given to a coccidium from Rattus norvegicus. Therefore, it is replaced by Eimeria lainsoni nom. nov.

  3. Isospora coerebae n. sp. (Apicomplexa: Eimeriidae from the bananaquit Coereba flaveola (Passeriformes: Coerebidae in South America Isospora coerebae n. sp. do caga-sebo Coereba flaveola (Passeriformes: Coerebidae na América do Sul

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    Bruno Pereira Berto

    2011-03-01

    Full Text Available The present study describes a new isosporoid coccidian parasite from the bananaquit Coereba flaveola, in Brazil. This new species is similar to I. cagasebi, but it can be distinguished by the size and shape of Stieda and susbstieda bodies. Isospora coerebae n. sp. oocysts are spheroidal to sub-spheroidal, 24.8 × 23.3 µm, with a smooth and bi-layered wall, ~1.2 µm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are elongate ovoidal, 17.9 × 10.9 µm. Stieda and substieda bodies are present. Sporocyst residuum is present and sporozoites have a posterior refractile body.Um novo parasito coccídio isosporóide do caga-sebo Coereba flaveola, do Brasil, é relatado no estudo atual. Essa nova espécie é semelhante à Isospora cagasebi, no entanto, pode ser distinguida pelos tamanho e forma dos corpos de Stieda e substieda. Os oocistos de I. coerebae n. sp. são esféricos a subesféricos, 24,8 × 23,3 µm, com parede dupla e lisa, ~ 1,2 µm. A micrópila, resíduo e grânulo polar do oocisto estão ausentes. Os esporocistos são ovóides alongados, 17,9 × 10,9 µm. Os corpos de Stieda e substieda estão presentes. O resíduo do esporocisto está presente e os esporozoítos possuem um corpo refrátil posterior.

  4. Cystoisospora canis (Apicomplexa: Sarcocystidae): development of monozoic tissue cysts in human cells, demonstration of egress of zoites from tissue cysts, and demonstration of repeat monozoic tissue cyst formation by zoites.

    Science.gov (United States)

    Houk, Alice E; Lindsay, David S

    2013-11-01

    Sporozoites of Cystoisospora canis penetrated and developed to monozoic tissue cysts in 4 human, 1 monkey, 1 bovine and 2 canine cell lines. No asexual division was documented although multiple infection of a single cell was observed. Examination of cultures using transmission electron microscopy demonstrated that they were monozoic tissue cysts and contained a single sporozoite. The appearance of monozoic tissue cysts in all cell lines was similar but the parasitophorous vacuole surrounding some sporozoites in DH82 dog macrophages was swollen. Monozoic tissue cysts were observed for up to 127 days in human pigmented retinal epithelial cells. Treatment of cell cultures containing monozoic tissue cysts with 0.75 sodium taurocholic acid and 0.25% trypsin stimulated egress of zoites (former sporozoites) from tissue cysts. Zoites collected from monozoic tissue cysts were able to penetrate and develop to monozoic tissue cysts in new host cells. Monozoic tissue cysts survived exposure to acid pepsin solution indicating that they would be orally infectious. The tissue cyst wall surrounding zoites did not autofluoresce as did oocyst and sporocyst walls exposed to UV light. We believe that C. canis can be used as a model system to study extra-intestinal monozoic tissue cysts stages of Cystoisospora belli of humans.

  5. Coprology of a single Northern white-breasted hedgehog (Erinaceus roumanicus): first report of Isospora rastegaievae in Poland.

    Science.gov (United States)

    Pyziel, Anna M; Jeżewski, Witold

    2016-09-01

    Coprological analysis of a sample from one free-living hedgehog was done with the use of a direct flotation method with additional incubation of fecal material. The study revealed three types of eggs and oocysts in the feces. The most commonly diagnosed were oocysts of Isospora rastegaievae (543/3g), while oocysts of Monocystis sp. (267/3g) and eggs of Aonchotheca/Eucoleus spp. (52/3g) were seen less often. This is the first report of coccidia I. rastegaievae (Apicomplexa: Eimeriida) and acephaline gregarine Monocystis sp. (Apicomplexa: Eugregarinida) infection in a hedgehog in Poland. PMID:27447231

  6. Repertoire of theileria equi antigens bound by equine antibody during persistent phase of infection

    Science.gov (United States)

    Theileriosis in horses and cattle is caused by tick-borne Apicomplexa parasites that cause death or persist for life in their respective hosts. Due to transmission risk associated with persistence, infection severely limits movement of horses and cattle between countries. The recent reemergence of T...

  7. Cell fractionation of parasitic protozoa: a review

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    Souza Wanderley de

    2003-01-01

    Full Text Available Cell fractionation, a methodological strategy for obtaining purified organelle preparations, has been applied successfully to parasitic protozoa by a number of investigators. Here we present and discuss the work of several groups that have obtained highly purified subcellular fractions from trypanosomatids, Apicomplexa and trichomonads, and whose work have added substantially to our knowledge of the cell biology of these parasites.

  8. Sequencing of the smallest Apicomplexan genome from the human pathogen Babesia microti†

    Science.gov (United States)

    Cornillot, Emmanuel; Hadj-Kaddour, Kamel; Dassouli, Amina; Noel, Benjamin; Ranwez, Vincent; Vacherie, Benoît; Augagneur, Yoann; Brès, Virginie; Duclos, Aurelie; Randazzo, Sylvie; Carcy, Bernard; Debierre-Grockiego, Françoise; Delbecq, Stéphane; Moubri-Ménage, Karina; Shams-Eldin, Hosam; Usmani-Brown, Sahar; Bringaud, Frédéric; Wincker, Patrick; Vivarès, Christian P.; Schwarz, Ralph T.; Schetters, Theo P.; Krause, Peter J.; Gorenflot, André; Berry, Vincent; Barbe, Valérie; Ben Mamoun, Choukri

    2012-01-01

    We have sequenced the genome of the emerging human pathogen Babesia microti and compared it with that of other protozoa. B. microti has the smallest nuclear genome among all Apicomplexan parasites sequenced to date with three chromosomes encoding ∼3500 polypeptides, several of which are species specific. Genome-wide phylogenetic analyses indicate that B. microti is significantly distant from all species of Babesidae and Theileridae and defines a new clade in the phylum Apicomplexa. Furthermore, unlike all other Apicomplexa, its mitochondrial genome is circular. Genome-scale reconstruction of functional networks revealed that B. microti has the minimal metabolic requirement for intraerythrocytic protozoan parasitism. B. microti multigene families differ from those of other protozoa in both the copy number and organization. Two lateral transfer events with significant metabolic implications occurred during the evolution of this parasite. The genomic sequencing of B. microti identified several targets suitable for the development of diagnostic assays and novel therapies for human babesiosis. PMID:22833609

  9. Mitosis in the Human Malaria Parasite Plasmodium falciparum ▿

    OpenAIRE

    Gerald, Noel; Mahajan, Babita; Kumar, Sanjai

    2011-01-01

    Malaria is caused by intraerythrocytic protozoan parasites belonging to Plasmodium spp. (phylum Apicomplexa) that produce significant morbidity and mortality, mostly in developing countries. Plasmodium parasites have a complex life cycle that includes multiple stages in anopheline mosquito vectors and vertebrate hosts. During the life cycle, the parasites undergo several cycles of extreme population growth within a brief span, and this is critical for their continued transmission and a contri...

  10. Efficient Gene Disruption in Diverse Strains of Toxoplasma gondii Using CRISPR/CAS9

    OpenAIRE

    Shen, Bang; Brown, Kevin M; Lee, Tobie D.; Sibley, L. David

    2014-01-01

    ABSTRACT Toxoplasma gondii has become a model for studying the phylum Apicomplexa, in part due to the availability of excellent genetic tools. Although reverse genetic tools are available in a few widely utilized laboratory strains, they rely on special genetic backgrounds that are not easily implemented in natural isolates. Recent progress in modifying CRISPR (clustered regularly interspaced short palindromic repeats), a system of DNA recognition used as a defense mechanism in bacteria and a...

  11. Ionophore-Resistant Mutants of Toxoplasma gondii Reveal Host Cell Permeabilization as an Early Event in Egress

    OpenAIRE

    Black, Michael W.; Arrizabalaga, Gustavo; John C Boothroyd

    2000-01-01

    Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa. Invasion and egress by this protozoan parasite are rapid events that are dependent upon parasite motility and appear to be directed by fluctuations in intracellular [Ca2+]. Treatment of infected host cells with the calcium ionophore A23187 causes the parasites to undergo rapid egress in a process termed ionophore-induced egress (IIE). In contrast, when extracellular parasites are exposed to this ionophore, ...

  12. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen

    OpenAIRE

    Jodie Lopez; Amina Bittame; Céline Massera; Virginie Vasseur; Grégory Effantin; Anne Valat; Célia Buaillon; Sophie Allart; Barbara A. Fox; Leah M. Rommereim; David J. Bzik; Guy Schoehn; Winfried Weissenhorn; Jean-François Dubremetz; Jean Gagnon

    2015-01-01

    Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV), resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN) of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effecto...

  13. 4-Bromophenacyl Bromide Specifically Inhibits Rhoptry Secretion during Toxoplasma Invasion

    OpenAIRE

    Sandeep Ravindran; Lodoen, Melissa B.; Verhelst, Steven H.L.; Matthew Bogyo; Boothroyd, John C.

    2009-01-01

    Toxoplasma gondii is a eukaryotic parasite of the phylum Apicomplexa that is able to infect a wide variety of host cells. During its active invasion process it secretes proteins from discrete secretory organelles: the micronemes, rhoptries and dense granules. Although a number of rhoptry proteins have been shown to be involved in important interactions with the host cell, very little is known about the mechanism of secretion of any Toxoplasma protein into the host cell. We used a chemical inh...

  14. Malaria immunity in man and mosquito: insights into unsolved mysteries of a deadly infectious disease

    OpenAIRE

    Crompton, Peter D.; Moebius, Jacqueline; Portugal, Silvia; Waisberg, Michael; Hart, Geoffrey; Garver, Lindsey S.; Louis H Miller; Barillas, Carolina; Pierce, Susan K.

    2014-01-01

    Malaria is a mosquito-borne disease caused by parasites of the obligate intracellular Apicomplexa family, the most deadly of which, Plasmodium falciparum, prevails in Africa. Malaria imposes a huge health burden on the world’s most vulnerable populations, claiming the lives of nearly a million children and pregnant women each year in Africa alone. Although there is keen interest in eradicating malaria, we do not yet have the necessary tools to meet this challenge, including an effective malar...

  15. Biochemische Charakterisierung der Zyklin-abhängigen Kinase 2,Aktivator-Komplexe des Parasiten Eimeria tenella sowie deren Nutzung in der Wirkstoffforschung

    OpenAIRE

    Suarez Fernandez, Maria Luisa

    2012-01-01

    Der Stamm der Apicomplexa ist eine artenreiche Gruppe, der einzellige, meist obligat intrazelluläre Parasiten angehören, darunter auch erstzunehmende Krankheitserreger wie Plasmodium sp. sowie tierpathogene Vertreter wie Eimeria sp. und Theileria sp. Eimeria sp. verursacht die Kokzidiose beim Huhn. Diese Krankheit bedingt weltweite Verluste in der Geflügelindustrie von etwa 3 Milliarden US$ pro Jahr [DALLOUL & LILLEHOJ, 2006; SHIRLEY et al., 2007; LUCIUS & LOOS-FRANK, 2008]. Die Parasiten wei...

  16. Use of proteinase K in the excystation of Sarcocystis cruzi sporocysts for in vitro culture and DNA extraction.

    Science.gov (United States)

    Ndiritu, W; Cawthorn, R J; Kibenge, F S

    1994-03-01

    Proteinase K was used for the cleaning of Sarcocystis cruzi (Apicomplexa) sporocysts prior to excystation. Bovine pulmonary endothelial cell cultures inoculated with the excysted sporozoites remained free of bacterial contamination for the duration of the experiment and had high yields of merozoites. The excysted sporozoites also yielded genomic DNA that could be labelled efficiently with 32P dATP by the random priming method.

  17. Sarcocystis neurona Merozoites Express a Family of Immunogenic Surface Antigens That Are Orthologues of the Toxoplasma gondii Surface Antigens (SAGs) and SAG-Related Sequences†

    OpenAIRE

    Howe, Daniel K.; Rajshekhar Y Gaji; Mroz-Barrett, Meaghan; Gubbels, Marc-Jan; Striepen, Boris; Stamper, Shelby

    2005-01-01

    Sarcocystis neurona is a member of the Apicomplexa that causes myelitis and encephalitis in horses but normally cycles between the opossum and small mammals. Analysis of an S. neurona expressed sequence tag (EST) database revealed four paralogous proteins that exhibit clear homology to the family of surface antigens (SAGs) and SAG-related sequences of Toxoplasma gondii. The primary peptide sequences of the S. neurona proteins are consistent with the two-domain structure that has been describe...

  18. Recent advances in understanding apicomplexan parasites [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Frank Seeber

    2016-06-01

    Full Text Available Intracellular single-celled parasites belonging to the large phylum Apicomplexa are amongst the most prevalent and morbidity-causing pathogens worldwide. In this review, we highlight a few of the many recent advances in the field that helped to clarify some important aspects of their fascinating biology and interaction with their hosts. Plasmodium falciparum causes malaria, and thus the recent emergence of resistance against the currently used drug combinations based on artemisinin has been of major interest for the scientific community. It resulted in great advances in understanding the resistance mechanisms that can hopefully be translated into altered future drug regimens. Apicomplexa are also experts in host cell manipulation and immune evasion. Toxoplasma gondii and Theileria sp., besides Plasmodium sp., are species that secrete effector molecules into the host cell to reach this aim. The underlying molecular mechanisms for how these proteins are trafficked to the host cytosol (T. gondii and Plasmodium and how a secreted protein can immortalize the host cell (Theileria sp. have been illuminated recently. Moreover, how such secreted proteins affect the host innate immune responses against T. gondii and the liver stages of Plasmodium has also been unraveled at the genetic and molecular level, leading to unexpected insights. Methodological advances in metabolomics and molecular biology have been instrumental to solving some fundamental puzzles of mitochondrial carbon metabolism in Apicomplexa. Also, for the first time, the generation of stably transfected Cryptosporidium parasites was achieved, which opens up a wide variety of experimental possibilities for this understudied, important apicomplexan pathogen.

  19. Recent advances in understanding apicomplexan parasites

    Science.gov (United States)

    Seeber, Frank; Steinfelder, Svenja

    2016-01-01

    Intracellular single-celled parasites belonging to the large phylum Apicomplexa are amongst the most prevalent and morbidity-causing pathogens worldwide. In this review, we highlight a few of the many recent advances in the field that helped to clarify some important aspects of their fascinating biology and interaction with their hosts. Plasmodium falciparum causes malaria, and thus the recent emergence of resistance against the currently used drug combinations based on artemisinin has been of major interest for the scientific community. It resulted in great advances in understanding the resistance mechanisms that can hopefully be translated into altered future drug regimens. Apicomplexa are also experts in host cell manipulation and immune evasion. Toxoplasma gondii and Theileria sp., besides Plasmodium sp., are species that secrete effector molecules into the host cell to reach this aim. The underlying molecular mechanisms for how these proteins are trafficked to the host cytosol ( T. gondii and Plasmodium) and how a secreted protein can immortalize the host cell ( Theileria sp.) have been illuminated recently. Moreover, how such secreted proteins affect the host innate immune responses against T. gondii and the liver stages of Plasmodium has also been unraveled at the genetic and molecular level, leading to unexpected insights. Methodological advances in metabolomics and molecular biology have been instrumental to solving some fundamental puzzles of mitochondrial carbon metabolism in Apicomplexa. Also, for the first time, the generation of stably transfected Cryptosporidium parasites was achieved, which opens up a wide variety of experimental possibilities for this understudied, important apicomplexan pathogen. PMID:27347391

  20. In silico analysis of the cyclophilin repertoire of apicomplexan parasites

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    von Samson-Himmelstjerna Georg

    2009-06-01

    Full Text Available Abstract Background Cyclophilins (Cyps are peptidyl cis/trans isomerases implicated in diverse processes such as protein folding, signal transduction, and RNA processing. They are also candidate drug targets, in particular for the immunosuppressant cyclosporine A. In addition, cyclosporine is known to exhibit anti-parasitic effects on a wide range of organisms including several apicomplexa. In order to obtain new non-immunosuppressive drugs targeting apicomplexan cyclophilins, a profound knowledge of the cyclophilin repertoire of this phylum would be necessary. Results BLAST and maximum likelihood analyses identified 16 different cyclophilin subfamilies within the genomes of Cryptosporidium hominis, Toxoplasma gondii, Plasmodium falciparum, Theileria annulata, Theileria parva, and Babesia bovis. In addition to good statistical support from the phylogenetic analysis, these subfamilies are also confirmed by comparison of cyclophilin domain architecture. Within an individual genome, the number of different Cyp genes that could be deduced varies between 7–9 for Cryptosporidia and 14 for T. gondii. Many of the putative apicomplexan cyclophilins are predicted to be nuclear proteins, most of them presumably involved in RNA processing. Conclusion The genomes of apicomplexa harbor a cyclophilin repertoire that is at least as complex as that of most fungi. The identification of Cyp subfamilies that are specific for lower eukaryotes, apicomplexa, or even the genus Plasmodium is of particular interest since these subfamilies are not present in host cells and might therefore represent attractive drug targets.

  1. The Conoid Associated Motor MyoH Is Indispensable for Toxoplasma gondii Entry and Exit from Host Cells.

    Science.gov (United States)

    Graindorge, Arnault; Frénal, Karine; Jacot, Damien; Salamun, Julien; Marq, Jean Baptiste; Soldati-Favre, Dominique

    2016-01-01

    Many members of the phylum of Apicomplexa have adopted an obligate intracellular life style and critically depend on active invasion and egress from the infected cells to complete their lytic cycle. Toxoplasma gondii belongs to the coccidian subgroup of the Apicomplexa, and as such, the invasive tachyzoite contains an organelle termed the conoid at its extreme apex. This motile organelle consists of a unique polymer of tubulin fibres and protrudes in both gliding and invading parasites. The class XIV myosin A, which is conserved across the Apicomplexa phylum, is known to critically contribute to motility, invasion and egress from infected cells. The MyoA-glideosome is anchored to the inner membrane complex (IMC) and is assumed to translocate the components of the circular junction secreted by the micronemes and rhoptries, to the rear of the parasite. Here we comprehensively characterise the class XIV myosin H (MyoH) and its associated light chains. We show that the 3 alpha-tubulin suppressor domains, located in MyoH tail, are necessary to anchor this motor to the conoid. Despite the presence of an intact MyoA-glideosome, conditional disruption of TgMyoH severely compromises parasite motility, invasion and egress from infected cells. We demonstrate that MyoH is necessary for the translocation of the circular junction from the tip of the parasite, where secretory organelles exocytosis occurs, to the apical position where the IMC starts. This study attributes for the first time a direct function of the conoid in motility and invasion, and establishes the indispensable role of MyoH in initiating the first step of motility along this unique organelle, which is subsequently relayed by MyoA to enact effective gliding and invasion.

  2. The Conoid Associated Motor MyoH Is Indispensable for Toxoplasma gondii Entry and Exit from Host Cells.

    Directory of Open Access Journals (Sweden)

    Arnault Graindorge

    2016-01-01

    Full Text Available Many members of the phylum of Apicomplexa have adopted an obligate intracellular life style and critically depend on active invasion and egress from the infected cells to complete their lytic cycle. Toxoplasma gondii belongs to the coccidian subgroup of the Apicomplexa, and as such, the invasive tachyzoite contains an organelle termed the conoid at its extreme apex. This motile organelle consists of a unique polymer of tubulin fibres and protrudes in both gliding and invading parasites. The class XIV myosin A, which is conserved across the Apicomplexa phylum, is known to critically contribute to motility, invasion and egress from infected cells. The MyoA-glideosome is anchored to the inner membrane complex (IMC and is assumed to translocate the components of the circular junction secreted by the micronemes and rhoptries, to the rear of the parasite. Here we comprehensively characterise the class XIV myosin H (MyoH and its associated light chains. We show that the 3 alpha-tubulin suppressor domains, located in MyoH tail, are necessary to anchor this motor to the conoid. Despite the presence of an intact MyoA-glideosome, conditional disruption of TgMyoH severely compromises parasite motility, invasion and egress from infected cells. We demonstrate that MyoH is necessary for the translocation of the circular junction from the tip of the parasite, where secretory organelles exocytosis occurs, to the apical position where the IMC starts. This study attributes for the first time a direct function of the conoid in motility and invasion, and establishes the indispensable role of MyoH in initiating the first step of motility along this unique organelle, which is subsequently relayed by MyoA to enact effective gliding and invasion.

  3. Cell division in Apicomplexan parasites is organized by a homolog of the striated rootlet fiber of algal flagella.

    Science.gov (United States)

    Francia, Maria E; Jordan, Carly N; Patel, Jay D; Sheiner, Lilach; Demerly, Jessica L; Fellows, Justin D; de Leon, Jessica Cruz; Morrissette, Naomi S; Dubremetz, Jean-François; Striepen, Boris

    2012-01-01

    Apicomplexa are intracellular parasites that cause important human diseases including malaria and toxoplasmosis. During host cell infection new parasites are formed through a budding process that parcels out nuclei and organelles into multiple daughters. Budding is remarkably flexible in output and can produce two to thousands of progeny cells. How genomes and daughters are counted and coordinated is unknown. Apicomplexa evolved from single celled flagellated algae, but with the exception of the gametes, lack flagella. Here we demonstrate that a structure that in the algal ancestor served as the rootlet of the flagellar basal bodies is required for parasite cell division. Parasite striated fiber assemblins (SFA) polymerize into a dynamic fiber that emerges from the centrosomes immediately after their duplication. The fiber grows in a polarized fashion and daughter cells form at its distal tip. As the daughter cell is further elaborated it remains physically tethered at its apical end, the conoid and polar ring. Genetic experiments in Toxoplasma gondii demonstrate two essential components of the fiber, TgSFA2 and 3. In the absence of either of these proteins cytokinesis is blocked at its earliest point, the initiation of the daughter microtubule organizing center (MTOC). Mitosis remains unimpeded and mutant cells accumulate numerous nuclei but fail to form daughter cells. The SFA fiber provides a robust spatial and temporal organizer of parasite cell division, a process that appears hard-wired to the centrosome by multiple tethers. Our findings have broader evolutionary implications. We propose that Apicomplexa abandoned flagella for most stages yet retained the organizing principle of the flagellar MTOC. Instead of ensuring appropriate numbers of flagella, the system now positions the apical invasion complexes. This suggests that elements of the invasion apparatus may be derived from flagella or flagellum associated structures.

  4. Análise dos padróns de diversidade xenética e epidemioloxía das especies e variedades de Cryptosporidium que parasitan humanos mediante o desenrolo dun protocolo multilocus de tipado xenético de alto rendemento

    OpenAIRE

    Abal Fabeiro, José Luis

    2016-01-01

    A criptosporidiose é unha enfermidade causada por un grupo de protozoos pertencentes ó phylum Apicomplexa que cursa xeralmente en forma de diarreas autolimitadas acompañadas de episodios de dor abdominal e vómitos. A falla dun tratamento específico contra dita doenza, a patoloxía soe resolverse de forma espontánea en poucas semanas, aínda que pode resultar letal en doentes inmunocomprometidos e naqueles países en vías de desenvolvemento destaca a súa potencial capacidade de compromete-lo norm...

  5. Infección por protozoarios en individuos de tití bebe leche (saguinus fuscicollis), tití cabeza blanca (saguinus oedipus), tití ardilla (saimiri sciureus), suricata (suricata suricatta) y wallabie (macropus rufogriseus)

    OpenAIRE

    López Acosta, G. L. K.; Peña, J. (Jorge); Brieva, C. I.

    2014-01-01

    La toxoplasmosis es una de las zoonosis parasitarias más comunes y de especial atención en medicina humana y veterinaria en todo el mundo. Toxoplasma gondii comparte muchos de sus parámetros biológicos con otros parásitos apicomplexa, pero es único en su extremadamente amplio rango de huéspedes y su especificidad tisular (Smith, 1995). La susceptibilidad en especies de primates del Nuevo Mundo y macrópodos a la infección por protozoarios es alta. Bajo condiciones de cautiverio la toxoplasmosi...

  6. 畜禽隐孢子虫病

    Institute of Scientific and Technical Information of China (English)

    彭德旺; 黄秀萍

    1993-01-01

    隐孢子虫隶属于原生动物界(Protozoa),顶器门(Apicomplexa)、孢子虫纲(Sporozoea)、球虫亚纲(Coccidia)、真球虫目(Eucoccidida)、艾美球虫亚目(Eimeriorina)、隐孢子虫科(Cryptosporidiidae)、隐孢子虫属(Cryptosporidium)(Levine等,1980)。迄今已发现可寄生在哺乳类、鸟类、爬行类及鱼类等44种动和人。

  7. Structures of parasitic CDPK domains point to a common mechanism of activation

    Energy Technology Data Exchange (ETDEWEB)

    Wernimont, Amy K.; Amani, Merhnaz; Qiu, Wei; Pizarro, Juan C.; Artz, Jennifer D.; Lin, Yu-Hui; Lew, Jocelyn; Hutchinson, Ashley; Hui, Raymond (Toronto)

    2011-11-23

    We recently determined the first structures of inactivated and calcium-activated calcium-dependent protein kinases (CDPKs) from Apicomplexa. Calcium binding triggered a large conformational change that constituted a new mechanism in calcium signaling and a novel EF-hand fold (CAD, for CDPK activation domain). Thus we set out to determine if this mechanism was universal to all CDPKs. We solved additional CDPK structures, including one from the species Plasmodium. We highlight the similarities in sequence and structure across apicomplexan and plant CDPKs, and strengthen our observations that this novel mechanism could be universal to canonical CDPKs. Our new structures demonstrate more detailed steps in the mechanism of calcium activation and possible key players in regulation. Residues involved in making the largest conformational change are the most conserved across Apicomplexa, leading us to propose that the mechanism is indeed conserved. CpCDPK3{_}CAD and PfCDPK{_}CAD were captured at a possible intermediate conformation, lending insight into the order of activation steps. PfCDPK3{_}CAD adopts an activated fold, despite having an inactive EF-hand sequence in the N-terminal lobe. We propose that for most apicomplexan CDPKs, the mode of activation will be similar to that seen in our structures, while specific regulation of the inactive and active forms will require further investigation.

  8. The apicomplexan inner membrane complex.

    Science.gov (United States)

    Kono, Maya; Prusty, Dhaneswar; Parkinson, John; Gilberger, Tim W

    2013-06-01

    Dinoflagellates, apicomplexans and ciliates are members of the monophyletic supergroup of Alveolata. The protists of this phylogenetic cluster have adapted to various ecological niches and lifestyles. Dinoflagellates and cilates can be found in any aquatic environment, whereas the phylum Apicomplexa solely comprises intracellular parasites. Despite their diversity all alveolates are united by the presence of membranous vesicles, so called alveoli, located beneath the plasma membrane. In addition to strengthening the cytoskeleton, these vesicles appear to possess taxon-specific functionality. In dinoflagellates and ciliates the alveoli predominantly play a structural role and can function as calcium stores. However, for the Apicomplexa, the alveolar vesicles -here jointly called the inner membrane complex (IMC)- are additionally involved in invasion of the host cell and are important scaffold elements during cytokinesis. Recent studies shed light on the architecture of the apicomplexan IMC and the number and diversity of its constituent proteins. This plethora of proteins and their varying evolutionary origin underlines the versatility of the IMC as a result of the adaption to a parasitic lifestyle.

  9. A novel family of Apicomplexan glideosome-associated proteins with an inner membrane-anchoring role.

    Science.gov (United States)

    Bullen, Hayley E; Tonkin, Christopher J; O'Donnell, Rebecca A; Tham, Wai-Hong; Papenfuss, Anthony T; Gould, Sven; Cowman, Alan F; Crabb, Brendan S; Gilson, Paul R

    2009-09-11

    The phylum Apicomplexa are a group of obligate intracellular parasites responsible for a wide range of important diseases. Central to the lifecycle of these unicellular parasites is their ability to migrate through animal tissue and invade target host cells. Apicomplexan movement is generated by a unique system of gliding motility in which substrate adhesins and invasion-related proteins are pulled across the plasma membrane by an underlying actin-myosin motor. The myosins of this motor are inserted into a dual membrane layer called the inner membrane complex (IMC) that is sandwiched between the plasma membrane and an underlying cytoskeletal basket. Central to our understanding of gliding motility is the characterization of proteins residing within the IMC, but to date only a few proteins are known. We report here a novel family of six-pass transmembrane proteins, termed the GAPM family, which are highly conserved and specific to Apicomplexa. In Plasmodium falciparum and Toxoplasma gondii the GAPMs localize to the IMC where they form highly SDS-resistant oligomeric complexes. The GAPMs co-purify with the cytoskeletal alveolin proteins and also to some degree with the actin-myosin motor itself. Hence, these proteins are strong candidates for an IMC-anchoring role, either directly or indirectly tethering the motor to the cytoskeleton.

  10. Inconsistencies of genome annotations in apicomplexan parasites revealed by 5'-end-one-pass and full-length sequences of oligo-capped cDNAs

    Directory of Open Access Journals (Sweden)

    Sugano Sumio

    2009-07-01

    Full Text Available Abstract Background Apicomplexan parasites are causative agents of various diseases including malaria and have been targets of extensive genomic sequencing. We generated 5'-EST collections for six apicomplexa parasites using our full-length oligo-capping cDNA library method. To improve upon the current genome annotations, as well as to validate the importance for physical cDNA clone resources, we generated a large-scale collection of full-length cDNAs for several apicomplexa parasites. Results In this study, we used a total of 61,056 5'-end-single-pass cDNA sequences from Plasmodium falciparum, P. vivax, P. yoelii, P. berghei, Cryptosporidium parvum, and Toxoplasma gondii. We compared these partially sequenced cDNA sequences with the currently annotated gene models and observed significant inconsistencies between the two datasets. In particular, we found that on average 14% of the exons in the current gene models were not supported by any cDNA evidence, and that 16% of the current gene models may contain at least one mis-annotation and should be re-evaluated. We also identified a large number of transcripts that had been previously unidentified. For 732 cDNAs in T. gondii, the entire sequences were determined in order to evaluate the annotated gene models at the complete full-length transcript level. We found that 41% of the T. gondii gene models contained at least one inconsistency. We also identified and confirmed by RT-PCR 140 previously unidentified transcripts found in the intergenic regions of the current gene annotations. We show that the majority of these discrepancies are due to questionable predictions of one or two extra exons in the upstream or downstream regions of the genes. Conclusion Our data indicates that the current gene models are likely to still be incomplete and have much room for improvement. Our unique full-length cDNA information is especially useful for further refinement of the annotations for the genomes of

  11. Gibberellin biosynthetic inhibitors make human malaria parasite Plasmodium falciparum cells swell and rupture to death.

    Directory of Open Access Journals (Sweden)

    Tomoko Toyama

    Full Text Available Malaria remains as one of the most devastating infectious disease, and continues to exact an enormous toll in medical cost and days of labor lost especially in the tropics. Effective malaria control and eventual eradication remain a huge challenge, with efficacious antimalarials as important intervention/management tool. Clearly new alternative drugs that are more affordable and with fewer side effects are desirable. After preliminary in vitro assays with plant growth regulators and inhibitors, here, we focus on biosynthetic inhibitors of gibberellin, a plant hormone with many important roles in plant growth, and show their inhibitory effect on the growth of both apicomplexa, Plasmodium falciparum and Toxoplasma gondii. Treatment of P. falciparum cultures with the gibberellin biosynthetic inhibitors resulted in marked morphological changes that can be reversed to a certain degree under hyperosmotic environment. These unique observations suggest that changes in the parasite membrane permeability may explain the pleiotropic effects observed within the intracellular parasites.

  12. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen.

    Science.gov (United States)

    Lopez, Jodie; Bittame, Amina; Massera, Céline; Vasseur, Virginie; Effantin, Grégory; Valat, Anne; Buaillon, Célia; Allart, Sophie; Fox, Barbara A; Rommereim, Leah M; Bzik, David J; Schoehn, Guy; Weissenhorn, Winfried; Dubremetz, Jean-François; Gagnon, Jean; Mercier, Corinne; Cesbron-Delauw, Marie-France; Blanchard, Nicolas

    2015-12-15

    Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV), resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN) of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effectors GRA2 and GRA6. We show that membrane association regulates access of the GRA6 protective antigen to the MHC I pathway in infected cells. Although insertion of GRA6 in the PV membrane is key for immunogenicity, association of GRA6 with the IVN limits presentation and curtails GRA6-specific CD8 responses in mice. Thus, membrane deformations of the PV regulate access of antigens to the MHC class I pathway, and the IVN may play a role in immune modulation. PMID:26628378

  13. Ocurrence of Cryptosporidium spp. in Amazonian manatees (Trichechus inunguis, Natterer, 1883

    Directory of Open Access Journals (Sweden)

    Maria Aparecida da Glória Faustino

    2007-09-01

    Full Text Available The apicomplexa protozoa Cryptosporidium infects several mammals, including terrestrial and aquatic species. In the epidemiology of this infection, the ingestion of water and/or food contamined with oocysts comprises the main mechanism of transmission to susceptible animals. Among the Sirenians, the occurrence of this coccidium has been reported in dugongs (Dugong dugon and Antillean manatee (Trichechus manatus manatus. The present study was conducted with the aim of verifying the occurrence of Cryptosporidium spp. in Amazonian manatee. For this purpose, fecal samples were collected from ten free-ranging Amazonian manatees, two specimens in captivity, and 103 supernatants fecal samples. The samples were processed by the sedimentation method in formol-ether and Kinyoun stain technique for the presence of Cryptosporidium spp.. The positive samples were then submitted to Direct Immunoflorescence Test. The results showed 4.34% (05/115 of positive samples. This is the first report of Cryptosporidium spp. in the Amazonian manatee.

  14. Malaria immunity in man and mosquito: insights into unsolved mysteries of a deadly infectious disease.

    Science.gov (United States)

    Crompton, Peter D; Moebius, Jacqueline; Portugal, Silvia; Waisberg, Michael; Hart, Geoffrey; Garver, Lindsey S; Miller, Louis H; Barillas-Mury, Carolina; Pierce, Susan K

    2014-01-01

    Malaria is a mosquito-borne disease caused by parasites of the obligate intracellular Apicomplexa phylum the most deadly of which, Plasmodium falciparum, prevails in Africa. Malaria imposes a huge health burden on the world's most vulnerable populations, claiming the lives of nearly one million children and pregnant women each year. Although there is keen interest in eradicating malaria, we do not yet have the necessary tools to meet this challenge, including an effective malaria vaccine and adequate vector control strategies. Here we review what is known about the mechanisms at play in immune resistance to malaria in both the human and mosquito hosts at each step in the parasite's complex life cycle with a view toward developing the tools that will contribute to the prevention of disease and death and, ultimately, to the goal of malaria eradication. In so doing, we hope to inspire immunologists to participate in defeating this devastating disease. PMID:24655294

  15. Malaria immunity in man and mosquito: insights into unsolved mysteries of a deadly infectious disease

    Science.gov (United States)

    Crompton, Peter D.; Moebius, Jacqueline; Portugal, Silvia; Waisberg, Michael; Hart, Geoffrey; Garver, Lindsey S.; Miller, Louis H.; Barillas, Carolina; Pierce, Susan K.

    2014-01-01

    Malaria is a mosquito-borne disease caused by parasites of the obligate intracellular Apicomplexa family, the most deadly of which, Plasmodium falciparum, prevails in Africa. Malaria imposes a huge health burden on the world’s most vulnerable populations, claiming the lives of nearly a million children and pregnant women each year in Africa alone. Although there is keen interest in eradicating malaria, we do not yet have the necessary tools to meet this challenge, including an effective malaria vaccine and adequate vector control strategies. Here we review what is known about the mechanisms at play in immune resistance to malaria in both the human and mosquito hosts at each step in the parasite’s complex life cycle with a view towards developing the tools that will contribute to the prevention of disease and death and ultimately the goal of malaria eradication. In so doing we hope to inspire immunologists to participate in defeating this devastating disease. PMID:24655294

  16. Morphology, Ultrastructure and Life Cycle of Vitrella brassicaformis n. sp., n. gen., a Novel Chromerid from the Great Barrier Reef

    KAUST Repository

    Oborník, Miroslav

    2012-03-01

    Chromerida are photoautotrophic alveolates so far only isolated from corals in Australia. It has been shown that these secondary plastid-containing algae are closely related to apicomplexan parasites and share various morphological and molecular characters with both Apicomplexa and Dinophyta. So far, the only known representative of the phylum was Chromera velia. Here we provide a formal description of another chromerid, Vitrella brassicaformis gen. et sp. nov., complemented with a detailed study on its ultrastructure, allowing insight into its life cycle. The novel alga differs significantly from the related chromerid C. velia in life cycle, morphology as well as the plastid genome. Analysis of photosynthetic pigments on the other hand demonstrate that both chromerids lack chlorophyll c, the hallmark of phototrophic chromalveolates. Based on the relatively high divergence between C. velia and V. brassicaformis, we propose their classification into distinct families Chromeraceae and Vitrellaceae. Moreover, we predict a hidden and unexplored diversity of the chromerid algae. © 2011 Elsevier GmbH.

  17. Immunity to gastrointestinal microparasites of fish.

    Science.gov (United States)

    Sitjà-Bobadilla, Ariadna; Estensoro, Itziar; Pérez-Sánchez, Jaume

    2016-11-01

    Fish intestinal parasites cause direct mortalities and also morbidity, poor growth, higher susceptibility to opportunistic pathogens and lower resistance to stress. This review is focused on microscopic parasites (Protozoa and Metazoa) that invade the gastrointestinal tract of fish. Intracellular parasites (mainly Microsporidia and Apicomplexa) evoke almost no host immune reaction while they are concealed in the cytoplasmic and nuclear compartments, and can even use fish cells (macrophages) as Trojan horses to spread in the host. Inflammatory reaction only appears when the parasite bursts infected cells. Immunity against extracellular parasites is depicted for the myxozoans Ceratonova shasta and Enteromyxum spp. The cellular and humoral innate responses and the production of antibodies are crucial for resolving some of these myxozoonoses, but an excessive inflammatory reaction (concerted by cytokines) can become a fatal pathophysiological consequence. The local immune response plays a key role, with numerous genes more strongly regulated in the intestine than at lymphohaematopoietic organs. PMID:26828391

  18. Emergence of Mutations in the K13 Propeller Gene of Plasmodium falciparum Isolates from Dakar, Senegal, in 2013-2014.

    Science.gov (United States)

    Boussaroque, Agathe; Fall, Bécaye; Madamet, Marylin; Camara, Cheikhou; Benoit, Nicolas; Fall, Mansour; Nakoulima, Aminata; Dionne, Pierre; Fall, Kadidiatou Ba; Diatta, Bakary; Diémé, Yaya; Wade, Boubacar; Pradines, Bruno

    2016-01-01

    The kelch 13 (K13) propeller gene is associated with artemisinin resistance. In a previous work, there were no mutations found in 138 Plasmodium falciparum isolates collected in 2012 and 2013 from patients residing in Dakar, Senegal (M. Torrentino-Madamet et al., Malar J 13:472, 2014, http://dx.doi.org/10.1186/1475-2875-13-472). However, the N554H, Q613H, and V637I mutations were identified in the propeller region of K13 in 92 (5.5%) isolates in 2013 and 2014. There were five polymorphisms identified in the Plasmodium/Apicomplexa-specific domain (K123R, N137S, N142NN/NNN, T149S, and K189T/N). PMID:26503652

  19. Novel type of linear mitochondrial genomes with dual flip-flop inversion system in apicomplexan parasites, Babesia microti and Babesia rodhaini

    Science.gov (United States)

    2012-01-01

    Background Mitochondrial (mt) genomes vary considerably in size, structure and gene content. The mt genomes of the phylum Apicomplexa, which includes important human pathogens such as the malaria parasite Plasmodium, also show marked diversity of structure. Plasmodium has a concatenated linear mt genome of the smallest size (6-kb); Babesia and Theileria have a linear monomeric mt genome (6.5-kb to 8.2-kb) with terminal inverted repeats; Eimeria, which is distantly related to Plasmodium and Babesia/Theileria, possesses a mt genome (6.2-kb) with a concatemeric form similar to that of Plasmodium; Cryptosporidium, the earliest branching lineage within the phylum Apicomplexa, has no mt genome. We are interested in the evolutionary origin of linear mt genomes of Babesia/Theileria, and have investigated mt genome structures in members of archaeopiroplasmid, a lineage branched off earlier from Babesia/Theileria. Results The complete mt genomes of archaeopiroplasmid parasites, Babesia microti and Babesia rodhaini, were sequenced. The mt genomes of B. microti (11.1-kb) and B. rodhaini (6.9-kb) possess two pairs of unique inverted repeats, IR-A and IR-B. Flip-flop inversions between two IR-As and between two IR-Bs appear to generate four distinct genome structures that are present at an equi-molar ratio. An individual parasite contained multiple mt genome structures, with 20 copies and 2 – 3 copies per haploid nuclear genome in B. microti and B. rodhaini, respectively. Conclusion We found a novel linear monomeric mt genome structure of B. microti and B. rhodhaini equipped with dual flip-flop inversion system, by which four distinct genome structures are readily generated. To our knowledge, this study is the first to report the presence of two pairs of distinct IR sequences within a monomeric linear mt genome. The present finding provides insight into further understanding of evolution of mt genome structure. PMID:23151128

  20. Novel type of linear mitochondrial genomes with dual flip-flop inversion system in apicomplexan parasites, Babesia microti and Babesia rodhaini

    Directory of Open Access Journals (Sweden)

    Hikosaka Kenji

    2012-11-01

    Full Text Available Abstract Background Mitochondrial (mt genomes vary considerably in size, structure and gene content. The mt genomes of the phylum Apicomplexa, which includes important human pathogens such as the malaria parasite Plasmodium, also show marked diversity of structure. Plasmodium has a concatenated linear mt genome of the smallest size (6-kb; Babesia and Theileria have a linear monomeric mt genome (6.5-kb to 8.2-kb with terminal inverted repeats; Eimeria, which is distantly related to Plasmodium and Babesia/Theileria, possesses a mt genome (6.2-kb with a concatemeric form similar to that of Plasmodium; Cryptosporidium, the earliest branching lineage within the phylum Apicomplexa, has no mt genome. We are interested in the evolutionary origin of linear mt genomes of Babesia/Theileria, and have investigated mt genome structures in members of archaeopiroplasmid, a lineage branched off earlier from Babesia/Theileria. Results The complete mt genomes of archaeopiroplasmid parasites, Babesia microti and Babesia rodhaini, were sequenced. The mt genomes of B. microti (11.1-kb and B. rodhaini (6.9-kb possess two pairs of unique inverted repeats, IR-A and IR-B. Flip-flop inversions between two IR-As and between two IR-Bs appear to generate four distinct genome structures that are present at an equi-molar ratio. An individual parasite contained multiple mt genome structures, with 20 copies and 2 – 3 copies per haploid nuclear genome in B. microti and B. rodhaini, respectively. Conclusion We found a novel linear monomeric mt genome structure of B. microti and B. rhodhaini equipped with dual flip-flop inversion system, by which four distinct genome structures are readily generated. To our knowledge, this study is the first to report the presence of two pairs of distinct IR sequences within a monomeric linear mt genome. The present finding provides insight into further understanding of evolution of mt genome structure.

  1. Solar radiation induces non-nuclear perturbations and a false start to regulated exocytosis in Cryptosporidium parvum.

    Directory of Open Access Journals (Sweden)

    Brendon J King

    Full Text Available Stratospheric ozone depletion, climate warming and acidification of aquatic ecosystems have resulted in elevated levels of solar radiation reaching many aquatic environments with an increased deleterious impact on a wide range of living organisms. While detrimental effects on living organisms are thought to occur primarily through DNA damage, solar UV can also damage cellular proteins, lipids and signalling pathways. Cryptosporidium, a member of the eukaryotic phylum Apicomplexa, contain numerous vesicular secretory organelles and their discharge via regulated exocytosis is essential for the successful establishment of infection. Using flow cytometric techniques we demonstrate that solar UV rapidly induces sporozoite exocytosis resulting in a significant reduction in the ability of sporozoites to attach and invade host cells. We found that solar UV induced sporozoite membrane depolarization, resulting in reduced cellular ATP and increased cytosolic calcium. These changes were accompanied by a reduction in the internal granularity of sporozoites, indicative of apical organelle discharge, which was confirmed by analysis of sporozoites with an exocytosis-sensitive dye. The precise timing of apical organelle discharge in the presence of a compatible host cell is critical for sporozoite attachment and invasion. Our results demonstrate for the first time how solar UV radiation can interfere with exocytosis, a fundamental cellular process in all eukaryotic cells. We contend that not only may the forecast increases in solar radiation in both aquatic and terrestrial environments significantly affect members of the Apicomplexa, solar UV-induced membrane depolarizations resulting in cytosolic calcium perturbation may affect a wider range of eukaryotic organisms through antagonistic effects on a myriad of calcium dependant cellular functions.

  2. Protein kinases of the human malaria parasite Plasmodium falciparum: the kinome of a divergent eukaryote

    Directory of Open Access Journals (Sweden)

    Packer Jeremy

    2004-10-01

    Full Text Available Abstract Background Malaria, caused by the parasitic protist Plasmodium falciparum, represents a major public health problem in the developing world. The P. falciparum genome has been sequenced, which provides new opportunities for the identification of novel drug targets. Eukaryotic protein kinases (ePKs form a large family of enzymes with crucial roles in most cellular processes; hence malarial ePKS represent potential drug targets. We report an exhaustive analysis of the P. falciparum genomic database (PlasmoDB aimed at identifying and classifying all ePKs in this organism. Results Using a variety of bioinformatics tools, we identified 65 malarial ePK sequences and constructed a phylogenetic tree to position these sequences relative to the seven established ePK groups. Predominant features of the tree were: (i that several malarial sequences did not cluster within any of the known ePK groups; (ii that the CMGC group, whose members are usually involved in the control of cell proliferation, had the highest number of malarial ePKs; and (iii that no malarial ePK clustered with the tyrosine kinase (TyrK or STE groups, pointing to the absence of three-component MAPK modules in the parasite. A novel family of 20 ePK-related sequences was identified and called FIKK, on the basis of a conserved amino acid motif. The FIKK family seems restricted to Apicomplexa, with 20 members in P. falciparum and just one member in some other Apicomplexan species. Conclusion The considerable phylogenetic distance between Apicomplexa and other Eukaryotes is reflected by profound divergences between the kinome of malaria parasites and that of yeast or mammalian cells.

  3. Expression of Cryptosporidium parvum Cpa135/CpCCP1 chimeras in Giardia duodenalis: organization of the protein domains affects the protein secretion pathway.

    Science.gov (United States)

    Lalle, Marco; Rosati, Maria Adelaide; Bien, Justina; Hehl, Adrian B; Pozio, Edoardo; Tosini, Fabio

    2011-03-01

    Cpa135 is a multidomain antigenic protein secreted at the sporozoite stage of the Apicomplexa protozoan Cryptosporidium parvum. Previous studies have shown that the protozoan flagellate parasite Giardia duodenalis is a suitable system for the heterologous expression of secreted proteins of Apicomplexa. Here, we designed three different Cpa135 variants fused to a C-terminal HA tag in order to test their expression in G. duodenalis under the control of the inducible promoter of the cyst wall protein 1 gene (cwp1). The three Cpa135 chimeras encompassed different portions of the protein; CpaG encodes the entire polypeptide of 1574 amino acids (aa); CpaGΔC includes the first 826 aa at the N-terminus; and CpaGΔN consists in of the final 833 aa at the C-terminus. Immunoblot experiments showed that CpaG and CpaGΔN maintained the epitopes recognized by anti-C. parvum-specific human serum. The intracellular localization and transport of the three Cpa135 variants were studied by immunofluorescence in combination with G. duodenalis-specific antibodies. CpaGΔC was mainly accumulated in the endoplasmic reticulum and the intact form was also excreted in the medium. Differently, the Cpa135 chimeras possessing an intact C-terminus (CpaG and CpaGΔN) were transported towards the forming cyst wall possibly and were not detected in the medium. Furthermore, the full-length CpaG was incorporated into the cyst wall. The data presented suggest that the C-terminus of Cpa135, which includes a cysteine reach domain, could influence the secretion of the chimeric proteins. PMID:21112325

  4. Parasites of economically important bivalves from the southern coast of Bahia State, Brazil Parasitos de bivalves de interesse econômico no Litoral Sul do Estado da Bahia, Brasil

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    Gabriela Calvi Zeidan

    2012-12-01

    Full Text Available This study investigated the parasites of three commercially important bivalve species (Crassostrea rhizophorae, Mytella guyanensis and Lucina pectinata from the southern coast of Bahia, Brazil. A total of 540 specimens were collected in August 2009 and February 2010, at three localities. The bivalve specimens were measured on their longest axis, opened, and macroscopically examined for the presence of parasites or signs of disease. They were then fixed in Davidson' solution and subjected to routine histological processing, with paraffin embedding and H&E staining; next, the specimens were examined under a light microscope. No parasites were observed associated with L. pectinata. Rickettsia-like organisms (RLOs, Sphenophrya sp. (Ciliophora, Nematopsis sp. (Apicomplexa, Urastoma sp. (Turbellaria and Bucephalus sp. (Digenea were observed in both C. rhizophorae and M. guyanensis, as well as Ancistrocoma sp. (Ciliophora and Tylocephalum sp. (Cestoda in the former. A high prevalence of Nematopsis sp. was seen, but caused no apparent damage to the host. Bucephalus sp. caused the destruction of tissues, with castration, but showed low prevalence. The other parasites occurred in low prevalence and intensity, without causing significant damage.Neste estudo foram investigados os parasitos de três espécies de bivalves de interesse econômico (Crassostrea rhizophorae, Mytella guyanensis e Lucina pectinata da Bahia. Foram analisados 540 exemplares, obtidos em duas coletas (agosto-2009 e fevereiro-2010, em três localidades. Os bivalves foram medidos quanto ao seu maior eixo, abertos e examinados macroscopicamente quanto à presença de parasitos ou sinais de enfermidades. Depois disso, foram fixados em solução de Davidson e processados por rotina de histologia, com inclusão em parafina e coloração com H&E. O material foi examinado ao microscópio de luz. Nenhum parasito esteve associado a L. pectinata. Bactérias do tipo RLOs (organismos assemelhados a

  5. 弓形虫与疟原虫入侵引起宿主细胞骨架重组相关GTP酶不同定位的观察%Observation on different localization of GTPases related to host cytoskeleton reorganization triggered by Toxoplasma gondii and Plasmodium falciparum infection

    Institute of Scientific and Technical Information of China (English)

    陈艾媛; 娜仁花; 彭鸿娟; 赵亚

    2012-01-01

    Both Toxoplasmagondii and Plasmodium spp. belong to the intracellular protozoa in Order Eucoccidiida, Class Sporozoea, and Phylum Apicomplexa. They dwell in the parasitophorons vaenole lor parasitism , development and multiplication alter recruitment . The invasion of these intracellular protozoans into host cells requires the cytoskeleton reorganization of the host cell . Rho GTPases are the important enzymes in regulation of cytoskeleton reorganization in mammalian cells inclu -ding nucleated cells and erythrocytes . We found in our research that host cell RhoA and Racl GTPase were recruited to the par-asitophorous vacuole membrane (PV M ) of T. gondii and showed a high accumulation on the PV M after T. gondii tachyzoite invading the host cell. On the other hand , this accumulation of the Rho GTPases on the PV M was not observed after Plasmodium falciparum merozoites invading erythrocytes . The different distribution of RhoA and RaclGTPase in the host cell after the invasion of T. gondii tachyzoites and Plasmodium falciparum merozoites indicated the different way for the regulation of cytoskeleton reorganization in host cells upon the parasites invasion .%目的 方法,结果,结论弓形虫与疟原虫均是顶复门(Phylum Apicomplexa),孢子纲(Class Sporozoea), 真球虫目(Order Eucoccidiida)的细胞内寄生原虫,入侵宿主细胞后均寄生于纳虫泡内进行发育增殖.细胞内寄生原虫的入侵均需要宿主细胞的细胞骨架发生重组,RhoGTP酶是哺乳动物细胞(有核细胞及红细胞)调节细胞骨架重组的重要酶类.我们在研究中发现宿主细胞的RhoA及Rac1GTP酶在弓形虫速殖子侵染后被纳入了纳虫泡膜(Parasitophorous Vacuole Membrane,PVM)上并高丰度聚集,然而在疟原虫裂殖子侵染的红细胞内却没有发现这两种GTP酶在纳虫泡膜上聚集的现象.宿主细胞RhoA及Rac1GTP酶在弓形虫及疟原虫感染宿主细胞后的不同分布,显示这两种原虫感染引起宿主细

  6. Ocorrência de anticorpos anti-Neospora caninum em pequenas propriedades leiteiras do Uruguai Occurrence of anti-Neospora caninum antibodies in small dairy farms in Uruguay

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    Agustín Furtado

    2011-04-01

    Full Text Available Neosporose é uma doença de distribuição mundial causada por um protozoário (Apicomplexa, Sarcocystidae, denominado Neospora caninum (N. caninum. Na América Latina, o protozoário foi diagnosticado no Uruguai, Brasil, Argentina, Chile, Paraguai e Peru. No Uruguai a prevalência em rebanhos leiteiros não foi determinada, havendo somente levantamentos sorológicos de algumas regiões do país em propriedades rurais de médio e grande porte. O objetivo deste trabalho foi determinar a presença de animais sorologicamente positivos contra N. caninum em bacias leiteiras de pequenas propriedades com baixos recursos socioeconômicos da zona central do Uruguai (Estados de Durazno e Tacuarembó. Utilizando um Kit de ELISA comercial, foram analisados 734 soros provenientes de vacas leiteiras adultas, obtendo-se 211 positivos (28,8%, 517 negativos (70,5% e seis animais com resultado não determinado (0,7%. Nossos resultados demonstram a exposição destes rebanhos ao parasito, sendo este o primeiro inquérito sorológico de N. caninum em bacias leiteiras de pequenas propriedades no Uruguai.Neosporosis is a worldwide disease caused by a protozoan (Apicomplexa, Sarcocystidae, called Neospora caninum (N. caninum. In Latin America was diagnosed in Uruguay, Brazil, Argentina, Chile, Paraguay and Peru. In Uruguay, the prevalence in dairy cattle is undetermined, with only a few reports in some areas from medium and large farmers. The main of this study was to determine the presence of serologically positive animals against N. caninum in small dairy farmers in critical context from central region of Uruguay (Departments of Durazno and Tacuarembó. Using a commercial ELISA kit, 734 sera of adult dairy cows were analyzed, resulting in 211 positive (28.8%, 517 negative (70.5% and six animals with uncertain outcome (0.7%. The results demonstrated the exposure of cattle to the parasite, which is the first serological survey of N. caninum in basins of small dairy

  7. Phylogenetic relationship of Hepatozoon blood parasites found in snakes from Africa, America and Asia.

    Science.gov (United States)

    Haklová, B; Majláthová, V; Majláth, I; Harris, D J; Petrilla, V; Litschka-Koen, T; Oros, M; Peťko, B

    2014-03-01

    The blood parasites from the genus Hepatozoon Miller, 1908 (Apicomplexa: Adeleida: Hepatozoidae) represent the most common intracellular protozoan parasites found in snakes. In the present study, we examined 209 individuals of snakes, from different zoogeographical regions (Africa, America, Asia and Europe), for the occurrence of blood parasites using both molecular and microscopic examination methods, and assess phylogenetic relationships of all Hepatozoon parasites from snakes for the first time. In total, 178 blood smears obtained from 209 individuals, representing 40 species, were examined, from which Hepatozoon unicellular parasites were found in 26 samples (14·6% prevalence). Out of 180 samples tested by molecular method polymerase chain reaction (PCR), the presence of parasites was observed in 21 individuals (prevalence 11·6%): 14 snakes from Africa belonging to six genera (Dendroaspis, Dispholidus, Mehelya, Naja, Philothamnus and Python), five snakes from Asia from the genus Morelia and two snakes from America, from two genera (Coluber and Corallus). The intensity of infection varied from one to 1433 infected cells per 10 000 erythrocytes. Results of phylogenetic analyses (Bayesian and Maximum Likelihood) revealed the existence of five haplotypes divided into four main lineages. The present data also indicate neither geographical pattern of studied Hepatozoon sp., nor congruency in the host association.

  8. Towards a molecular understanding of the apicomplexan actin motor: on a road to novel targets for malaria remedies?

    Energy Technology Data Exchange (ETDEWEB)

    Kumpula, Esa-Pekka [University of Oulu, PO Box 3000, 90014 Oulu (Finland); Helmholtz Centre for Infection Research, Notkestrasse 85, 22607 Hamburg (Germany); German Electron Synchrotron, Notkestrasse 85, 22607 Hamburg (Germany); Kursula, Inari, E-mail: inari.kursula@helmholtz-hzi.de [University of Oulu, PO Box 3000, 90014 Oulu (Finland); Helmholtz Centre for Infection Research, Notkestrasse 85, 22607 Hamburg (Germany); German Electron Synchrotron, Notkestrasse 85, 22607 Hamburg (Germany); University of Bergen, Jonas Lies vei 91, 5009 Bergen (Norway)

    2015-04-16

    In this review, current structural understanding of the apicomplexan glideosome and actin regulation is described. Apicomplexan parasites are the causative agents of notorious human and animal diseases that give rise to considerable human suffering and economic losses worldwide. The most prominent parasites of this phylum are the malaria-causing Plasmodium species, which are widespread in tropical and subtropical regions, and Toxoplasma gondii, which infects one third of the world’s population. These parasites share a common form of gliding motility which relies on an actin–myosin motor. The components of this motor and the actin-regulatory proteins in Apicomplexa have unique features compared with all other eukaryotes. This, together with the crucial roles of these proteins, makes them attractive targets for structure-based drug design. In recent years, several structures of glideosome components, in particular of actins and actin regulators from apicomplexan parasites, have been determined, which will hopefully soon allow the creation of a complete molecular picture of the parasite actin–myosin motor and its regulatory machinery. Here, current knowledge of the function of this motor is reviewed from a structural perspective.

  9. PRODUÇÃO DE HIBRIDOMAS SECRETORES DE ANTICORPOS ANTI- Neospora caninum PARA USO EM IMUNODIAGNÓSTICO

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    Bruna Alves Devens

    2014-06-01

    Full Text Available The Neospora caninum is a protozoan Apicomplexa with greater involvement in abortions worldwide. The economic losses determined by neosporosis also include abortions besides the early disposal of cows, costs for replacing animals in the herd, drop in milk production as well as milk in fat production. The immunological diagnosis involves purchasing costly diagnostic kits on the market. Therefore, the aim of this study was the production of hybridomas secreting polyclonal antibodies with affinity to Neospora caninum (Nc-1 strain for immunodiagnostic use. For antibodies production, we used sonicated protozoa from Vero cells in culture, purified by filtration. These tachyzoites were employed for immunization of BALB / c mice using saponin as adjuvant, which allowed obtaining polyclonal antibodies capable of revealing fluorescein reaction in indirect immunofluorescence. The fusion of splenic cells, from the immunized mice with myeloma cells SP2 / 0 resulted in 72.4% hybridomas secreting anti-Nc-1antibodies. These hybridomas secreted antibodies positive to N. caninum and negative to Toxoplasma gondii.

  10. The apical complex provides a regulated gateway for secretion of invasion factors in Toxoplasma.

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    Nicholas J Katris

    2014-04-01

    Full Text Available The apical complex is the definitive cell structure of phylum Apicomplexa, and is the focus of the events of host cell penetration and the establishment of intracellular parasitism. Despite the importance of this structure, its molecular composition is relatively poorly known and few studies have experimentally tested its functions. We have characterized a novel Toxoplasma gondii protein, RNG2, that is located at the apical polar ring--the common structural element of apical complexes. During cell division, RNG2 is first recruited to centrosomes immediately after their duplication, confirming that assembly of the new apical complex commences as one of the earliest events of cell replication. RNG2 subsequently forms a ring, with the carboxy- and amino-termini anchored to the apical polar ring and mobile conoid, respectively, linking these two structures. Super-resolution microscopy resolves these two termini, and reveals that RNG2 orientation flips during invasion when the conoid is extruded. Inducible knockdown of RNG2 strongly inhibits host cell invasion. Consistent with this, secretion of micronemes is prevented in the absence of RNG2. This block, however, can be fully or partially overcome by exogenous stimulation of calcium or cGMP signaling pathways, respectively, implicating the apical complex directly in these signaling events. RNG2 demonstrates for the first time a role for the apical complex in controlling secretion of invasion factors in this important group of parasites.

  11. Transcriptome of Aphanomyces euteiches: new oomycete putative pathogenicity factors and metabolic pathways.

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    Elodie Gaulin

    Full Text Available Aphanomyces euteiches is an oomycete pathogen that causes seedling blight and root rot of legumes, such as alfalfa and pea. The genus Aphanomyces is phylogenically distinct from well-studied oomycetes such as Phytophthora sp., and contains species pathogenic on plants and aquatic animals. To provide the first foray into gene diversity of A. euteiches, two cDNA libraries were constructed using mRNA extracted from mycelium grown in an artificial liquid medium or in contact to plant roots. A unigene set of 7,977 sequences was obtained from 18,864 high-quality expressed sequenced tags (ESTs and characterized for potential functions. Comparisons with oomycete proteomes revealed major differences between the gene content of A. euteiches and those of Phytophthora species, leading to the identification of biosynthetic pathways absent in Phytophthora, of new putative pathogenicity genes and of expansion of gene families encoding extracellular proteins, notably different classes of proteases. Among the genes specific of A. euteiches are members of a new family of extracellular proteins putatively involved in adhesion, containing up to four protein domains similar to fungal cellulose binding domains. Comparison of A. euteiches sequences with proteomes of fully sequenced eukaryotic pathogens, including fungi, apicomplexa and trypanosomatids, allowed the identification of A. euteiches genes with close orthologs in these microorganisms but absent in other oomycetes sequenced so far, notably transporters and non-ribosomal peptide synthetases, and suggests the presence of a defense mechanism against oxidative stress which was initially characterized in the pathogenic trypanosomatids.

  12. Characterization of eukaryotic microbial diversity in hypersaline Lake Tyrrell, Australia

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    Karla B Heidelberg

    2013-05-01

    Full Text Available This study describes the community structure of the microbial eukaryotic community from hypersaline Lake Tyrrell, Australia, using near full length 18S rRNA sequences. Water samples were taken in both summer and winter over a four year period. The extent of eukaryotic diversity detected was low, with only 35 unique phylotypes using a 97% sequence similarity threshold. The water samples were dominated (91% by a novel cluster of the Alveolate, Apicomplexa Colpodella spp., most closely related to C. edax. The Chlorophyte, Dunaliella spp. accounted for less than 35% of water column samples. However, the eukaryotic community entrained in a salt crust sample was vastly different and was dominated (83% by the Dunaliella spp. The patterns described here represent the first observation of microbial eukaryotic dynamics in this system and provide a multiyear comparison of community composition by season. The lack of expected seasonal distribution in eukaryotic communities paired with abundant nanoflagellates suggests that grazing may significantly structure microbial eukaryotic communities in this system.

  13. Structural and functional dissection of Toxoplasma gondii armadillo repeats only protein.

    Science.gov (United States)

    Mueller, Christina; Samoo, Atta; Hammoudi, Pierre-Mehdi; Klages, Natacha; Kallio, Juha Pekka; Kursula, Inari; Soldati-Favre, Dominique

    2016-03-01

    Rhoptries are club-shaped, regulated secretory organelles that cluster at the apical pole of apicomplexan parasites. Their discharge is essential for invasion and the establishment of an intracellular lifestyle. Little is known about rhoptry biogenesis and recycling during parasite division. In Toxoplasma gondii, positioning of rhoptries involves the armadillo repeats only protein (ARO) and myosin F (MyoF). Here, we show that two ARO partners, ARO-interacting protein (AIP) and adenylate cyclase β (ACβ) localize to a rhoptry subcompartment. In absence of AIP, ACβ disappears from the rhoptries. By assessing the contribution of each ARO armadillo (ARM) repeat, we provide evidence that ARO is multifunctional, participating not only in positioning but also in clustering of rhoptries. Structural analyses show that ARO resembles the myosin-binding domain of the Caenorhabditis elegans myosin chaperone UNC-45. A conserved patch of aromatic and acidic residues denotes the putative MyoF-binding site, and the overall arrangement of the ARM repeats explains the dramatic consequences of deleting each of them. Finally, Plasmodium falciparum ARO functionally complements ARO depletion and interacts with the same partners, highlighting the conservation of rhoptry biogenesis in Apicomplexa. PMID:26769898

  14. Theileria parasites secrete a prolyl isomerase to maintain host leukocyte transformation.

    Science.gov (United States)

    Marsolier, J; Perichon, M; DeBarry, J D; Villoutreix, B O; Chluba, J; Lopez, T; Garrido, C; Zhou, X Z; Lu, K P; Fritsch, L; Ait-Si-Ali, S; Mhadhbi, M; Medjkane, S; Weitzman, J B

    2015-04-16

    Infectious agents develop intricate mechanisms to interact with host cell pathways and hijack their genetic and epigenetic machinery to change host cell phenotypic states. Among the Apicomplexa phylum of obligate intracellular parasites, which cause veterinary and human diseases, Theileria is the only genus that transforms its mammalian host cells. Theileria infection of bovine leukocytes induces proliferative and invasive phenotypes associated with activated signalling pathways, notably JNK and AP-1 (ref. 2). The transformed phenotypes are reversed by treatment with the theilericidal drug buparvaquone. We used comparative genomics to identify a homologue of the peptidyl-prolyl isomerase PIN1 in T. annulata (TaPIN1) that is secreted into the host cell and modulates oncogenic signalling pathways. Here we show that TaPIN1 is a bona fide prolyl isomerase and that it interacts with the host ubiquitin ligase FBW7, leading to its degradation and subsequent stabilization of c-JUN, which promotes transformation. We performed in vitro and in silico analysis and in vivo zebrafish xenograft experiments to demonstrate that TaPIN1 is directly inhibited by the anti-parasite drug buparvaquone (and other known PIN1 inhibitors) and is mutated in a drug-resistant strain. Prolyl isomerization is thus a conserved mechanism that is important in cancer and is used by Theileria parasites to manipulate host oncogenic signalling.

  15. First Molecular Characterization of Theileria ornithorhynchi Mackerras, 1959: yet Another Challenge to the Systematics of the Piroplasms.

    Science.gov (United States)

    Paparini, Andrea; Macgregor, James; Ryan, Una M; Irwin, Peter J

    2015-12-01

    Piroplasms, tick-transmitted Apicomplexa of the genera Theileria, Babesia and Cytauxzoon, are blood-borne parasites of clinical and veterinary importance. The order Piroplasmida shows a puzzling systematics characterized by multiple clades, soft polytomies and paraphyletic/polyphyletic genera. In the present study, screening of platypuses (Ornithorhynchus anatinus), was performed to infer the parasite molecular phylogeny. DNA was extracted from blood, ectoparasites and tick eggs and the 18S rRNA- hsp70-genes were used for the phylogenetic reconstructions. Microscopic analyses detected pleomorphic intra-erythrocytic organisms and tetrads consistent with previous descriptions of Theileria ornithorhynchi Mackerras, 1959, but observation of possible schizonts could not be confirmed. DNA sequences obtained from blood and ticks allowed resolving the systematics of the first piroplasm infecting a monotreme host. Molecularly, T. ornithorhynchi formed a novel monophyletic group, basal to most known piroplasms' clades. The ancestral position of this clade, isolated from an ancient lineage of mammalian host appears particularly fascinating. The present paper discusses the inadequacies of the current molecular systematics for the Piroplasmida and the consequences of incomplete sampling, morphology-based classification and ambiguous microscopic identifications. Likely when the current sampling bias is rectified and more sequence data is made available, the phylogenetic position of T. ornithorhynchi will be further contextualized without ambiguity.

  16. Translational repression of the cpw-wpc gene family in the malaria parasite Plasmodium.

    Science.gov (United States)

    Rao, Pavitra N; Santos, Jorge M; Pain, Arnab; Templeton, Thomas J; Mair, Gunnar R

    2016-10-01

    The technical challenges of working with the sexual stages of the malaria parasite Plasmodium have hindered the characterization of sexual stage antigens in the quest for a successful malaria transmission-blocking vaccine. One such predicted and largely uncharacterized group of sexual stage candidate antigens is the CPW-WPC family of proteins. CPW-WPC proteins are named for a characteristic domain that contains two conserved motifs, CPxxW and WPC. Conserved across Apicomplexa, this family is also present earlier in the Alveolata in the free-living, non-parasitophorous, photosynthetic chromerids, Chromera and Vitrella. In Plasmodium falciparum and Plasmodium berghei blood stage parasites, the transcripts of all nine cpw-wpc genes have been detected in gametocytes. RNA immunoprecipitation followed by reverse transcriptase-PCR reveals all P. berghei cpw-wpc transcripts to be bound by the translational repressors DOZI and CITH, and thus are likely under translational control prior to transmission from the rodent host to the mosquito vector in P. berghei. The GFP tagging of two endogenous P. berghei genes confirmed translational silencing in the gametocyte and translation in ookinetes. By establishing a luciferase transgene assay, we show that the 3' untranslated region of PF3D7_1331400 controls protein expression of this reporter in P. falciparum gametocytes. Our analyses suggest that cpw-wpc genes are translationally silenced in gametocytes across Plasmodium spp. and activated during ookinete formation and thus may have a role in transmission to the mosquito. PMID:27312996

  17. Mechanisms of invasion from sporozoite and merozoíto of Plasmodium

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    Lilian M. Spencer

    2016-05-01

    Full Text Available Malaria or paludismo is caused in humans by four species of Plasmodium belonging to phylum Apicomplexa: ovale, malaria, vivax and falciparum, being the last, the responsible of the clinical complication and death in the vertebrate host. Plasmodium parasite possess a specialized secretory organelles called rhoptries, micronemes and dense granules that facilitate invasion of host cells. The sporozoite stage of Plasmodium travels through the different cells of vertebrate host until it reaches the hepatocyte and have been form the parasitophorous vacuole. The infected hepatocytes rupture, results in the releasing thousands of daughter merozoites that invade the erythrocytes with the formation of parasitophorous vacuole too. Several researchers suggest the gliding motility mechanism as the responsible of hepatocyte invasion. While, which the erythrocyte invasion process has been described as the result of tree steps: first contact, re-orientation and invasion. In this review the surface proteins of merozoites and esporozoites are pointed out as the most important factors for the molecular invasion mechanisms until the elaboration of the parasitophorous vacuole. These proteins that take part in these mechanisms are the possible candidates in the design of an anti-malaria vaccine.

  18. Subcompartmentalisation of proteins in the rhoptries correlates with ordered events of erythrocyte invasion by the blood stage malaria parasite.

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    Elizabeth S Zuccala

    Full Text Available Host cell infection by apicomplexan parasites plays an essential role in lifecycle progression for these obligate intracellular pathogens. For most species, including the etiological agents of malaria and toxoplasmosis, infection requires active host-cell invasion dependent on formation of a tight junction - the organising interface between parasite and host cell during entry. Formation of this structure is not, however, shared across all Apicomplexa or indeed all parasite lifecycle stages. Here, using an in silico integrative genomic search and endogenous gene-tagging strategy, we sought to characterise proteins that function specifically during junction-dependent invasion, a class of proteins we term invasins to distinguish them from adhesins that function in species specific host-cell recognition. High-definition imaging of tagged Plasmodium falciparum invasins localised proteins to multiple cellular compartments of the blood stage merozoite. This includes several that localise to distinct subcompartments within the rhoptries. While originating from the same organelle, however, each has very different dynamics during invasion. Apical Sushi Protein and Rhoptry Neck protein 2 release early, following the junction, whilst a novel rhoptry protein PFF0645c releases only after invasion is complete. This supports the idea that organisation of proteins within a secretory organelle determines the order and destination of protein secretion and provides a localisation-based classification strategy for predicting invasin function during apicomplexan parasite invasion.

  19. Putative monofunctional type I polyketide synthase units: a dinoflagellate-specific feature?

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    Karsten Eichholz

    Full Text Available Marine dinoflagellates (alveolata are microalgae of which some cause harmful algal blooms and produce a broad variety of most likely polyketide synthesis derived phycotoxins. Recently, novel polyketide synthesase (PKS transcripts have been described from the Florida red tide dinoflagellate Karenia brevis (gymnodiniales which are evolutionarily related to Type I PKS but were apparently expressed as monofunctional proteins, a feature typical of Type II PKS. Here, we investigated expression units of PKS I-like sequences in Alexandrium ostenfeldii (gonyaulacales and Heterocapsa triquetra (peridiniales at the transcript and protein level. The five full length transcripts we obtained were all characterized by polyadenylation, a 3' UTR and the dinoflagellate specific spliced leader sequence at the 5'end. Each of the five transcripts encoded a single ketoacylsynthase (KS domain showing high similarity to K. brevis KS sequences. The monofunctional structure was also confirmed using dinoflagellate specific KS antibodies in Western Blots. In a maximum likelihood phylogenetic analysis of KS domains from diverse PKSs, dinoflagellate KSs formed a clade placed well within the protist Type I PKS clade between apicomplexa, haptophytes and chlorophytes. These findings indicate that the atypical PKS I structure, i.e., expression as putative monofunctional units, might be a dinoflagellate specific feature. In addition, the sequenced transcripts harbored a previously unknown, apparently dinoflagellate specific conserved N-terminal domain. We discuss the implications of this novel region with regard to the putative monofunctional organization of Type I PKS in dinoflagellates.

  20. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites

    KAUST Repository

    Woo, Yong H.

    2015-07-15

    The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga. © Woo et al.

  1. Translational repression of the cpw-wpc gene family in the malaria parasite Plasmodium

    KAUST Repository

    Rao, Pavitra N.

    2016-06-14

    The technical challenges of working with the sexual stages of the malaria parasite Plasmodium have hindered the characterization of sexual stage antigens in the quest for a successful malaria transmission-blocking vaccine. One such predicted and largely uncharacterized group of sexual stage candidate antigens is the CPW-WPC family of proteins. CPW-WPC proteins are named for a characteristic domain that contains two conserved motifs, CPxxW and WPC. Conserved across Apicomplexa, this family is also present earlier in the Alveolata in the free-living, non-parasitophorous, photosynthetic chromerids, Chromera and Vitrella. In P. falciparum and P. berghei blood stage parasites the transcripts of all nine cpw-wpc genes have been detected in gametocytes. RNA immunoprecipitation followed by reverse transcriptase-PCR reveals all P. berghei cpw-wpc transcripts to be bound by the translational repressors DOZI and CITH, and thus are likely under translational control prior to transmission from the rodent host to the mosquito vector in P. berghei. The GFP tagging of two endogenous P. berghei genes confirmed translational silencing in the gametocyte and translation in ookinetes. Establishing a luciferase transgene assay we show that the 3′ untranslated region of PF3D7_1331400 controls protein expression of this reporter in P. falciparum gametocytes. Our analyses suggest that cpw-wpc genes are translationally silenced in gametocytes across Plasmodium spp. and activated during ookinete formation and thus may have a role in transmission to the mosquito.

  2. Prevalence of Protozoa Species in Drinking and Environmental Water Sources in Sudan

    Directory of Open Access Journals (Sweden)

    Salah Shanan

    2015-01-01

    Full Text Available Protozoa are eukaryotic cells distributed worldwide in nature and are receiving increasing attention as reservoirs and potential vectors for the transmission of pathogenic bacteria. In the environment, on the other hand, many genera of the protozoa are human and animal pathogens. Only limited information is available on these organisms in developing countries and so far no information on their presence is available from Sudan. It is necessary to establish a molecular identification of species of the protozoa from drinking and environmental water. 600 water samples were collected from five states (Gadarif, Khartoum, Kordofan, Juba, and Wad Madani in Sudan and analysed by polymerase chain reaction (PCR and sequencing. 57 out of 600 water samples were PCR positive for protozoa. 38 out of the 57 positive samples were identified by sequencing to contain 66 protozoa species including 19 (28.8% amoebae, 17 (25.7% Apicomplexa, 25 (37.9% ciliates, and 5 (7.6% flagellates. This study utilized molecular methods identified species belonging to all phyla of protozoa and presented a fast and accurate molecular detection and identification of pathogenic as well as free-living protozoa in water uncovering hazards facing public health.

  3. CenH3 evolution reflects meiotic symmetry as predicted by the centromere drive model.

    Science.gov (United States)

    Zedek, František; Bureš, Petr

    2016-09-15

    The centromere drive model explaining rapid evolution of eukaryotic centromeres predicts higher frequency of positive selection acting on centromeric histone H3 (CenH3) in clades with asymmetric meiosis compared to the clades with only symmetric meiosis. However, despite the impression one might get from the literature, this key prediction of the centromere drive model has not only never been confirmed, but it has never been tested, because all the previous studies dealt only with the presence or absence instead of the frequency of positive selection. To provide evidence for or against different frequencies of positively selected CenH3 in asymmetrics and symmetrics, we have inferred the selective pressures acting on CenH3 in seventeen eukaryotic clades, including plants, animals, fungi, ciliates and apicomplexa, using codon-substitution models, and compared the inferred frequencies between asymmetrics and symmetrics in a quantitative manner. We have found that CenH3 has been evolving adaptively much more frequently in clades with asymmetric meiosis compared with clades displaying only symmetric meiosis which confirms the prediction of centromere drive model. Our findings indicate that the evolution of asymmetric meiosis required CenH3 to evolve adaptively more often to counterbalance the negative consequences of centromere drive.

  4. Population Abundance of Potentially Pathogenic Organisms in Intestinal Microbiome of Jungle Crow (Corvus macrorhynchos Shown with 16S rRNA Gene-Based Microbial Community Analysis

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    Isamu Maeda

    2013-01-01

    Full Text Available Jungle Crows (Corvus macrorhynchos prefer human habitats because of their versatility in feeding accompanied with human food consumption. Therefore, it is important from a public health viewpoint to characterize their intestinal microbiota. However, no studies have been involved in molecular characterization of the microbiota based on huge and reliable number of data acquisition. In this study, 16S rRNA gene-based microbial community analysis coupled with the next-generation DNA sequencing techniques was applied to the taxonomic classification of intestinal microbiome for three jungle crows. Clustering of the reads into 130 operational taxonomic units showed that at least 70% of analyzed sequences for each crow were highly homologous to Eimeria sp., which belongs to the protozoan phylum Apicomplexa. The microbiotas of three crows also contained potentially pathogenic bacteria with significant percentages, such as the genera Campylobacter and Brachyspira. Thus, the profiling of a large number of 16S rRNA gene sequences in crow intestinal microbiomes revealed the high-frequency existence or vestige of potentially pathogenic microorganisms.

  5. Amplicon-Based Pyrosequencing Reveals High Diversity of Protistan Parasites in Ships' Ballast Water: Implications for Biogeography and Infectious Diseases.

    Science.gov (United States)

    Pagenkopp Lohan, K M; Fleischer, R C; Carney, K J; Holzer, K K; Ruiz, G M

    2016-04-01

    Ships' ballast water (BW) commonly moves macroorganisms and microorganisms across the world's oceans and along coasts; however, the majority of these microbial transfers have gone undetected. We applied high-throughput sequencing methods to identify microbial eukaryotes, specifically emphasizing the protistan parasites, in ships' BW collected from vessels calling to the Chesapeake Bay (Virginia and Maryland, USA) from European and Eastern Canadian ports. We utilized tagged-amplicon 454 pyrosequencing with two general primer sets, amplifying either the V4 or V9 domain of the small subunit (SSU) of the ribosomal RNA (rRNA) gene complex, from total DNA extracted from water samples collected from the ballast tanks of bulk cargo vessels. We detected a diverse group of protistan taxa, with some known to contain important parasites in marine systems, including Apicomplexa (unidentified apicomplexans, unidentified gregarines, Cryptosporidium spp.), Dinophyta (Blastodinium spp., Euduboscquella sp., unidentified syndinids, Karlodinium spp., Syndinium spp.), Perkinsea (Parvilucifera sp.), Opisthokonta (Ichthyosporea sp., Pseudoperkinsidae, unidentified ichthyosporeans), and Stramenopiles (Labyrinthulomycetes). Further characterization of groups with parasitic taxa, consisting of phylogenetic analyses for four taxa (Cryptosporidium spp., Parvilucifera spp., Labyrinthulomycetes, and Ichthyosporea), revealed that sequences were obtained from both known and novel lineages. This study demonstrates that high-throughput sequencing is a viable and sensitive method for detecting parasitic protists when present and transported in the ballast water of ships. These data also underscore the potential importance of human-aided dispersal in the biogeography of these microbes and emerging diseases in the world's oceans. PMID:26476551

  6. The contribution of DNA slippage to eukaryotic nuclear 18S rRNA evolution.

    Science.gov (United States)

    Hancock, J M

    1995-06-01

    Six of 204 eukaryotic nuclear small-subunit ribosomal RNA sequences analyzed show a highly significant degree of clustering of short sequence motifs that indicates the fixation of products of replication slippage within them in their recent evolutionary history. A further 72 sequences show weaker indications of sequence repetition. Repetitive sequences in SSU rRNAs are preferentially located in variable regions and in particular in V4 and V7. The conserved region immediately 5' to V7 (C7) is also consistently repetitive. Whereas variable regions vary in length and appear to have evolved by the fixation of slippage products, C7 shows no indication of length variation. Repetition within C7 is therefore either not a consequence of slippage or reflects very ancient slippage events. The phylogenetic distribution of sequence simplicity in small-subunit rRNAs is patchy, being largely confined to the Mammalia, Apicomplexa, Tetrahymenidae, and Trypanosomatidae. The regions of the molecule associated with sequence simplicity vary with taxonomic grouping as do the sequence motifs undergoing slippage. Comparison of rates of insertion and substitution in a lineage within the genus Plasmodium confirms that both rates are higher in variable regions than in conserved regions. The insertion rate in variable regions is substantially lower than the substitution rate, suggesting that selection acts more strongly on slippage products than on point mutations in these regions. Patterns of coevolution between variable regions may reflect the consequences of selection acting on the incorporation of slippage-derived sequences across the gene.

  7. Screening of potential targets in Plasmodium falciparum using stage-specific metabolic network analysis.

    Science.gov (United States)

    Dholakia, Neel; Dhandhukia, Pinakin; Roy, Nilanjan

    2015-11-01

    The Apicomplexa parasite Plasmodium is a major cause of death in developing countries which are less equipped to bring new medicines to the market. Currently available drugs used for treatment of malaria are limited either by inadequate efficacy, toxicity and/or increased resistance. Availability of the genome sequence, microarray data and metabolic profile of Plasmodium parasite offers an opportunity for the identification of stage-specific genes important to the organism's lifecycle. In this study, microarray data were analysed for differential expression and overlapped onto metabolic pathways to identify differentially regulated pathways essential for transition to successive erythrocytic stages. The results obtained indicate that S-adenosylmethionine decarboxylase/ornithine decarboxylase, a bifunctional enzyme required for polyamine synthesis, is important for the Plasmodium cell growth in the absence of exogenous polyamines. S-adenosylmethionine decarboxylase/ornithine decarboxylase is a valuable target for designing therapeutically useful inhibitors. One such inhibitor, [Formula: see text]-difluoromethyl ornithine, is currently in use for the treatment of African sleeping sickness caused by Trypanosoma brucei. Structural studies of ornithine decarboxylase along with known inhibitors and their analogues were carried out to screen drug databases for more effective and less toxic compounds. PMID:26303382

  8. Sarcocystid organisms found in bile from a dog with acute hepatitis: a case report and review of intestinal and hepatobiliary Sarcocystidae infections in dogs and cats.

    Science.gov (United States)

    Irvine, Katherine L; Walker, Julie M; Friedrichs, Kristen R

    2016-03-01

    Sarcocystidae is a family of coccidian protozoa from the phylum Apicomplexa that includes Toxoplasma, Neospora, Sarcocystis, Hammondia, and Besnoitia spp. All species undergo a 2-host sexual and asexual cycle. In the definitive host, replication is enteroepithelial, and infection is typically asymptomatic or less commonly causes mild diarrhea. Clinical disease is most frequently observed in the intermediate host, often as an aberrant infection, and is mostly associated with neurologic, muscular, or hepatic inflammation. Here, we review the literature regarding intestinal Sarcocystidae infections in dogs and cats, with emphasis on the life cycle stages and the available diagnostic assays and their limitations. We also report the diagnostic findings for an 11-year-old dog with acute neutrophilic hepatitis, biliary protozoa, and negative biliary culture. Although Toxoplasma and Neospora IgG titers were both high, PCR for these 2 organisms was negative for bile. The organisms were identified by 18S rDNA PCR as most consistent with Hammondia, either H heydorni or H triffittae. This is the first report of presumed Hammondia organisms being found in canine bile. PMID:26870918

  9. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen

    Directory of Open Access Journals (Sweden)

    Jodie Lopez

    2015-12-01

    Full Text Available Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV, resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effectors GRA2 and GRA6. We show that membrane association regulates access of the GRA6 protective antigen to the MHC I pathway in infected cells. Although insertion of GRA6 in the PV membrane is key for immunogenicity, association of GRA6 with the IVN limits presentation and curtails GRA6-specific CD8 responses in mice. Thus, membrane deformations of the PV regulate access of antigens to the MHC class I pathway, and the IVN may play a role in immune modulation.

  10. Organisation and sequence determination of glutamine-dependent carbamoyl phosphate synthetase II in Toxoplasma gondii.

    Science.gov (United States)

    Fox, Barbara A; Bzik, David J

    2003-01-01

    Carbamoyl phosphate synthetase II encodes the first enzymic step of de novo pyrimidine biosynthesis. Carbamoyl phosphate synthetase II is essential for Toxoplasma gondii replication and virulence. In this study, we characterised the primary structure of a 28kb gene encoding Toxoplasma gondii carbamoyl phosphate synthetase II. The carbamoyl phosphate synthetase II gene was interrupted by 36 introns. The predicted protein encoded by the 37 carbamoyl phosphate synthetase II exons was a 1,687 amino acid polypeptide with an N-terminal glutamine amidotransferase domain fused with C-terminal carbamoyl phosphate synthetase domains. This bifunctional organisation of carbamoyl phosphate synthetase II is unique, so far, to protozoan parasites from the phylum Apicomplexa (Plasmodium, Babesia, Toxoplasma) or zoomastigina (Trypanosoma, Leishmania). Apicomplexan parasites possessed the largest carbamoyl phosphate synthetase II enzymes due to insertions in the glutamine amidotransferase and carbamoyl phosphate synthetase domains that were not present in the corresponding gene segments from bacteria, plants, fungi and mammals. The C-terminal allosteric regulatory domain, the carbamoyl phosphate synthetase linker domain and the oligomerisation domain were also distinct from the corresponding domains in other species. The novel C-terminal regulatory domain may explain the lack of activation of Toxoplasma gondii carbamoyl phosphate synthetase II by the allosteric effector 5-phosphoribosyl 1-pyrophosphate. Toxoplasma gondii growth in vitro was markedly inhibited by the glutamine antagonist acivicin, an inhibitor of glutamine amidotransferase activity typically associated with carbamoyl phosphate synthetase II, guanosine monophosphate synthetase, or CTP synthetase. PMID:12547350

  11. Histopathological survey of the mussel Mytilus chilensis (Mytilidae and the clam Gari solida (Psammobiidae from southern Chile

    Directory of Open Access Journals (Sweden)

    Florencia Cremonte

    2015-03-01

    Full Text Available A total of 175 specimens of mussels, Mytilus chilensis (Mytilidae, and 56 specimens of clams, Gari solida (Psammobiidae, were collected in natural beds and culture sites of southern Chile. Juvenile mussel specimens (3 cm of maximum length were free of parasites and diseases, whilst the commercial sized populations was parasitized by intracellular inclusions of bacteria-like organisms in the digestive gland epithelium and in the gills, by ciliates in the gills, turbellarians similar to Paravortex (Rhabocoela in the intestine lumen and copepods attached to the gills. In addition, the disseminated neoplasia disease was also present although in low prevalences. In the clam, G. solida, prokariotic inclusions were found in the digestive gland epithelium and bacteria-like organisms in the gills, often encapsulated by haemocytes; oocysts containing up to 8 sporozoites similar to Nematopsis (Apicomplexa in the connective tissue, causing haemocytic infiltration when the intensity of infection was high; ciliates belonging to two different species (one of them similar to Trichodina inhabiting the gills; and a turbellarian similar to Paravortex in the lumen of digestive system without apparent host reaction. The populations of the bivalve species here studied were devoid of serious pathogens.

  12. 4-Bromophenacyl bromide specifically inhibits rhoptry secretion during Toxoplasma invasion.

    Science.gov (United States)

    Ravindran, Sandeep; Lodoen, Melissa B; Verhelst, Steven H L; Bogyo, Matthew; Boothroyd, John C

    2009-01-01

    Toxoplasma gondii is a eukaryotic parasite of the phylum Apicomplexa that is able to infect a wide variety of host cells. During its active invasion process it secretes proteins from discrete secretory organelles: the micronemes, rhoptries and dense granules. Although a number of rhoptry proteins have been shown to be involved in important interactions with the host cell, very little is known about the mechanism of secretion of any Toxoplasma protein into the host cell. We used a chemical inhibitor of phospholipase A2s, 4-bromophenacyl bromide (4-BPB), to look at the role of such lipases in the secretion of Toxoplasma proteins. We found that 4-BPB was a potent inhibitor of rhoptry secretion in Toxoplasma invasion. This drug specifically blocked rhoptry secretion but not microneme secretion, thus effectively showing that the two processes can be de-coupled. It affected parasite motility and invasion, but not attachment or egress. Using propargyl- or azido-derivatives of the drug (so-called click chemistry derivatives) and a series of 4-BPB-resistant mutants, we found that the drug has a very large number of target proteins in the parasite that are involved in at least two key steps: invasion and intracellular growth. This potent compound, the modified "click-chemistry" forms of it, and the resistant mutants should serve as useful tools to further study the processes of Toxoplasma early invasion, in general, and rhoptry secretion, in particular. PMID:19956582

  13. Unique apicomplexan IMC sub-compartment proteins are early markers for apical polarity in the malaria parasite.

    Science.gov (United States)

    Poulin, Benoit; Patzewitz, Eva-Maria; Brady, Declan; Silvie, Olivier; Wright, Megan H; Ferguson, David J P; Wall, Richard J; Whipple, Sarah; Guttery, David S; Tate, Edward W; Wickstead, Bill; Holder, Anthony A; Tewari, Rita

    2013-01-01

    The phylum Apicomplexa comprises over 5000 intracellular protozoan parasites, including Plasmodium and Toxoplasma, that are clinically important pathogens affecting humans and livestock. Malaria parasites belonging to the genus Plasmodium possess a pellicle comprised of a plasmalemma and inner membrane complex (IMC), which is implicated in parasite motility and invasion. Using live cell imaging and reverse genetics in the rodent malaria model P. berghei, we localise two unique IMC sub-compartment proteins (ISPs) and examine their role in defining apical polarity during zygote (ookinete) development. We show that these proteins localise to the anterior apical end of the parasite where IMC organisation is initiated, and are expressed at all developmental stages, especially those that are invasive. Both ISP proteins are N-myristoylated, phosphorylated and membrane-bound. Gene disruption studies suggest that ISP1 is likely essential for parasite development, whereas ISP3 is not. However, an absence of ISP3 alters the apical localisation of ISP1 in all invasive stages including ookinetes and sporozoites, suggesting a coordinated function for these proteins in the organisation of apical polarity in the parasite.

  14. Purification, crystallization and preliminary X-ray diffraction analysis of inner membrane complex (IMC) subcompartment protein 1 (ISP1) from Toxoplasma gondii.

    Science.gov (United States)

    Tonkin, Michelle L; Brown, Shannon; Beck, Josh R; Bradley, Peter J; Boulanger, Martin J

    2012-07-01

    The protozoan parasites of the Apicomplexa phylum are devastating global pathogens. Their success is largely due to phylum-specific proteins found in specialized organelles and cellular structures. The inner membrane complex (IMC) is a unique apicomplexan structure that is essential for motility, invasion and replication. The IMC subcompartment proteins (ISP) have recently been identified in Toxoplasma gondii and shown to be critical for replication, although their specific mechanisms are unknown. Structural characterization of TgISP1 was pursued in order to identify the fold adopted by the ISPs and to generate detailed insight into how this family of proteins functions during replication. An N-terminally truncated form of TgISP1 was purified from Escherichia coli, crystallized and subjected to X-ray diffraction analysis. Two crystal forms of TgISP1 belonging to space groups P4(1)32 or P4(3)32 and P2(1)2(1)2(1) diffracted to 2.05 and 2.1 Å resolution, respectively.

  15. A novel family of Toxoplasma IMC proteins displays a hierarchical organization and functions in coordinating parasite division.

    Science.gov (United States)

    Beck, Josh R; Rodriguez-Fernandez, Imilce A; de Leon, Jessica Cruz; Huynh, My-Hang; Carruthers, Vern B; Morrissette, Naomi S; Bradley, Peter J

    2010-09-09

    Apicomplexans employ a peripheral membrane system called the inner membrane complex (IMC) for critical processes such as host cell invasion and daughter cell formation. We have identified a family of proteins that define novel sub-compartments of the Toxoplasma gondii IMC. These IMC Sub-compartment Proteins, ISP1, 2 and 3, are conserved throughout the Apicomplexa, but do not appear to be present outside the phylum. ISP1 localizes to the apical cap portion of the IMC, while ISP2 localizes to a central IMC region and ISP3 localizes to a central plus basal region of the complex. Targeting of all three ISPs is dependent upon N-terminal residues predicted for coordinated myristoylation and palmitoylation. Surprisingly, we show that disruption of ISP1 results in a dramatic relocalization of ISP2 and ISP3 to the apical cap. Although the N-terminal region of ISP1 is necessary and sufficient for apical cap targeting, exclusion of other family members requires the remaining C-terminal region of the protein. This gate-keeping function of ISP1 reveals an unprecedented mechanism of interactive and hierarchical targeting of proteins to establish these unique sub-compartments in the Toxoplasma IMC. Finally, we show that loss of ISP2 results in severe defects in daughter cell formation during endodyogeny, indicating a role for the ISP proteins in coordinating this unique process of Toxoplasma replication.

  16. Composite genome map and recombination parameters derived from three archetypal lineages of Toxoplasma gondii

    Science.gov (United States)

    Khan, Asis; Taylor, Sonya; Su, Chunlei; Mackey, Aaron J.; Boyle, Jon; Cole, Robert; Glover, Darius; Tang, Keliang; Paulsen, Ian T.; Berriman, Matt; Boothroyd, John C.; Pfefferkorn, Elmer R.; Dubey, J. P.; Ajioka, James W.; Roos, David S.; Wootton, John C.; Sibley, L. David

    2005-01-01

    Toxoplasma gondii is a highly successful protozoan parasite in the phylum Apicomplexa, which contains numerous animal and human pathogens. T.gondii is amenable to cellular, biochemical, molecular and genetic studies, making it a model for the biology of this important group of parasites. To facilitate forward genetic analysis, we have developed a high-resolution genetic linkage map for T.gondii. The genetic map was used to assemble the scaffolds from a 10X shotgun whole genome sequence, thus defining 14 chromosomes with markers spaced at ∼300 kb intervals across the genome. Fourteen chromosomes were identified comprising a total genetic size of ∼592 cM and an average map unit of ∼104 kb/cM. Analysis of the genetic parameters in T.gondii revealed a high frequency of closely adjacent, apparent double crossover events that may represent gene conversions. In addition, we detected large regions of genetic homogeneity among the archetypal clonal lineages, reflecting the relatively few genetic outbreeding events that have occurred since their recent origin. Despite these unusual features, linkage analysis proved to be effective in mapping the loci determining several drug resistances. The resulting genome map provides a framework for analysis of complex traits such as virulence and transmission, and for comparative population genetic studies. PMID:15911631

  17. The life cycle of Gregarina cuneata in the midgut of Tribolium castaneum and the effects of parasitism on the development of insects.

    Science.gov (United States)

    Gigliolli, A A S; Julio, A H F; Conte, H

    2016-04-01

    Tribolium castaneum Herbst 1797 (Coleoptera: Tenebrionidae), an important pest of stored grains and byproducts, is naturally infected by Gregarina cuneata Stein 1848 (Apicomplexa: Gregarinidae). Changes in the life cycle of insects caused by the parasite development in the midgut were studied. Trophozoites, gamonts (solitary and associated), and gametocysts were present in the midgut of the insects. In young trophozoites, the apical region differentiated into an epimerite that firmly attached the parasite to the host epithelial cells. With maturation, trophozoites developed in gamonts that were associated with the initiation of sexual reproduction in the cell cycle, culminating in the formation of the spherical gametocyst. Morpho-functional analyses indicated that gregarines absorb nutrients from infected cells and can occlude the midgut as they develop. Consequently, nutritional depletion may interfere with the host's physiology, causing decreased growth, delayed development, and high mortality rates of the parasitized insects. These results suggest G. cuneata could be an important biological agent for controlling T. castaneum in integrated pest management programs.

  18. Detection of Babesia divergens in southern Norway by using an immunofluorescence antibody test in cow sera

    Directory of Open Access Journals (Sweden)

    Røed Knut H

    2010-10-01

    Full Text Available Abstract Background The incidence of bovine babesiosis, caused by Babesia divergens (Apicomplexa: Piroplasmida has decreased markedly since the 1930 s, but may re-emerge as a consequence of climate change and changes in legislation and pasturing practices. This is a potentially serious disease, with both economical and animal welfare consequences. Therefore, there is a need to survey the distribution of B. divergens. Methods We tested sera from 306 healthy pastured cows from 24 farms along the southern Norwegian coast by using an indirect immunofluorescence IgG antibody test (IFAT. Fractions of seropositive cows were compared by calculating 95% CI. Results The results of this test showed that 27% of the sera were positive for B. divergens antibodies. The fraction of antibody-positive sera that we detected showed a two-humped distribution, with a high fraction of positives being found in municipalities in the western and eastern parts of the study area, while the municipalities between these areas had few or no positive serum samples. Conclusions Neither the farmers' observations nor the Norwegian Dairy Herd Recording System give an adequate picture of the distribution of bovine babesiosis. Serological testing of cows by using IFAT is a convenient way of screening for the presence of B. divergens in an area.

  19. Subcompartmentalisation of proteins in the rhoptries correlates with ordered events of erythrocyte invasion by the blood stage malaria parasite.

    Science.gov (United States)

    Zuccala, Elizabeth S; Gout, Alexander M; Dekiwadia, Chaitali; Marapana, Danushka S; Angrisano, Fiona; Turnbull, Lynne; Riglar, David T; Rogers, Kelly L; Whitchurch, Cynthia B; Ralph, Stuart A; Speed, Terence P; Baum, Jake

    2012-01-01

    Host cell infection by apicomplexan parasites plays an essential role in lifecycle progression for these obligate intracellular pathogens. For most species, including the etiological agents of malaria and toxoplasmosis, infection requires active host-cell invasion dependent on formation of a tight junction - the organising interface between parasite and host cell during entry. Formation of this structure is not, however, shared across all Apicomplexa or indeed all parasite lifecycle stages. Here, using an in silico integrative genomic search and endogenous gene-tagging strategy, we sought to characterise proteins that function specifically during junction-dependent invasion, a class of proteins we term invasins to distinguish them from adhesins that function in species specific host-cell recognition. High-definition imaging of tagged Plasmodium falciparum invasins localised proteins to multiple cellular compartments of the blood stage merozoite. This includes several that localise to distinct subcompartments within the rhoptries. While originating from the same organelle, however, each has very different dynamics during invasion. Apical Sushi Protein and Rhoptry Neck protein 2 release early, following the junction, whilst a novel rhoptry protein PFF0645c releases only after invasion is complete. This supports the idea that organisation of proteins within a secretory organelle determines the order and destination of protein secretion and provides a localisation-based classification strategy for predicting invasin function during apicomplexan parasite invasion. PMID:23049965

  20. CenH3 evolution reflects meiotic symmetry as predicted by the centromere drive model

    Science.gov (United States)

    Zedek, František; Bureš, Petr

    2016-01-01

    The centromere drive model explaining rapid evolution of eukaryotic centromeres predicts higher frequency of positive selection acting on centromeric histone H3 (CenH3) in clades with asymmetric meiosis compared to the clades with only symmetric meiosis. However, despite the impression one might get from the literature, this key prediction of the centromere drive model has not only never been confirmed, but it has never been tested, because all the previous studies dealt only with the presence or absence instead of the frequency of positive selection. To provide evidence for or against different frequencies of positively selected CenH3 in asymmetrics and symmetrics, we have inferred the selective pressures acting on CenH3 in seventeen eukaryotic clades, including plants, animals, fungi, ciliates and apicomplexa, using codon-substitution models, and compared the inferred frequencies between asymmetrics and symmetrics in a quantitative manner. We have found that CenH3 has been evolving adaptively much more frequently in clades with asymmetric meiosis compared with clades displaying only symmetric meiosis which confirms the prediction of centromere drive model. Our findings indicate that the evolution of asymmetric meiosis required CenH3 to evolve adaptively more often to counterbalance the negative consequences of centromere drive. PMID:27629066

  1. Secretion of Antonospora (Paranosema) locustae proteins into infected cells suggests an active role of microsporidia in the control of host programs and metabolic processes.

    Science.gov (United States)

    Senderskiy, Igor V; Timofeev, Sergey A; Seliverstova, Elena V; Pavlova, Olga A; Dolgikh, Viacheslav V

    2014-01-01

    Molecular tools of the intracellular protozoan pathogens Apicomplexa and Kinetoplastida for manipulation of host cell machinery have been the focus of investigation for approximately two decades. Microsporidia, fungi-related microorganisms forming another large group of obligate intracellular parasites, are characterized by development in direct contact with host cytoplasm (the majority of species), strong minimization of cell machinery, and acquisition of unique transporters to exploit host metabolic system. All the aforementioned features are suggestive of the ability of microsporidia to modify host metabolic and regulatory pathways. Seven proteins of the microsporidium Antonospora (Paranosema) locustae with predicted signal peptides but without transmembrane domains were overexpressed in Escherichia coli. Western-blot analysis with antibodies against recombinant products showed secretion of parasite proteins from different functional categories into the infected host cell. Secretion of parasite hexokinase and α/β-hydrolase was confirmed by immunofluorescence microscopy. In addition, this method showed specific accumulation of A. locustae hexokinase in host nuclei. Expression of hexokinase, trehalase, and two leucine-rich repeat proteins without any exogenous signal peptide led to their secretion in the yeast Pichia pastoris. In contrast, α/β-hydrolase was not found in the culture medium, though a significant amount of this enzyme accumulated in the yeast membrane fraction. These results suggest that microsporidia possess a broad set of enzymes and regulatory proteins secreted into infected cells to control host metabolic processes and molecular programs. PMID:24705470

  2. Secretion of Antonospora (Paranosema locustae proteins into infected cells suggests an active role of microsporidia in the control of host programs and metabolic processes.

    Directory of Open Access Journals (Sweden)

    Igor V Senderskiy

    Full Text Available Molecular tools of the intracellular protozoan pathogens Apicomplexa and Kinetoplastida for manipulation of host cell machinery have been the focus of investigation for approximately two decades. Microsporidia, fungi-related microorganisms forming another large group of obligate intracellular parasites, are characterized by development in direct contact with host cytoplasm (the majority of species, strong minimization of cell machinery, and acquisition of unique transporters to exploit host metabolic system. All the aforementioned features are suggestive of the ability of microsporidia to modify host metabolic and regulatory pathways. Seven proteins of the microsporidium Antonospora (Paranosema locustae with predicted signal peptides but without transmembrane domains were overexpressed in Escherichia coli. Western-blot analysis with antibodies against recombinant products showed secretion of parasite proteins from different functional categories into the infected host cell. Secretion of parasite hexokinase and α/β-hydrolase was confirmed by immunofluorescence microscopy. In addition, this method showed specific accumulation of A. locustae hexokinase in host nuclei. Expression of hexokinase, trehalase, and two leucine-rich repeat proteins without any exogenous signal peptide led to their secretion in the yeast Pichia pastoris. In contrast, α/β-hydrolase was not found in the culture medium, though a significant amount of this enzyme accumulated in the yeast membrane fraction. These results suggest that microsporidia possess a broad set of enzymes and regulatory proteins secreted into infected cells to control host metabolic processes and molecular programs.

  3. Cloning and analysis of a Toxoplasma gondii histone acetyltransferase: a novel chromatin remodelling factor in Apicomplexan parasites.

    Science.gov (United States)

    Hettmann, C; Soldati, D

    1999-11-15

    The yeast transcriptional adaptor GCN5 functions as a histone acetyltransferase, directly linking chromatin modification to transcriptional regulation. Homologues of yeast GCN5 have been found in Tetrahymena, Drosophila, Arabidopsis and human, suggesting that this pathway of chromatin remodelling is evolutionarily conserved. Consistent with this view, we have identified the Toxoplasma gondii homologue, referred to here as TgGCN5. The gene codes for a protein of 474 amino acids with an estimated molecular mass of 53 kDa. The protein reveals two regions of close similarity with the GCN5 family members, the HAT domain and the bromodomain. Tg GCN5 occurs in a single copy in the T.gondii genome. The introduction of a second copy of TgGCN5 in T.gondii tachyzoites is toxic unless the HAT activity is disrupted by a single point mutation. Full TgGCN5 does not complement the growth defect in a yeast gcn5 (-)mutant strain, but a chimera comprising the T.gondii HAT domain fused to the remainder of yGCN5 does. These data show that T.gondii GNC5 is a histone acetyltransferase attesting to the significance of chromatin remodelling in gene regulation of Apicomplexa.

  4. Complex polymorphisms in the Plasmodium falciparum multidrug resistance protein 2 gene and its contribution to antimalarial response.

    Science.gov (United States)

    Veiga, Maria Isabel; Osório, Nuno S; Ferreira, Pedro Eduardo; Franzén, Oscar; Dahlstrom, Sabina; Lum, J Koji; Nosten, Francois; Gil, José Pedro

    2014-12-01

    Plasmodium falciparum has the capacity to escape the actions of essentially all antimalarial drugs. ATP-binding cassette (ABC) transporter proteins are known to cause multidrug resistance in a large range of organisms, including the Apicomplexa parasites. P. falciparum genome analysis has revealed two genes coding for the multidrug resistance protein (MRP) type of ABC transporters: Pfmrp1, previously associated with decreased parasite drug susceptibility, and the poorly studied Pfmrp2. The role of Pfmrp2 polymorphisms in modulating sensitivity to antimalarial drugs has not been established. We herein report a comprehensive account of the Pfmrp2 genetic variability in 46 isolates from Thailand. A notably high frequency of 2.8 single nucleotide polymorphisms (SNPs)/kb was identified for this gene, including some novel SNPs. Additionally, we found that Pfmrp2 harbors a significant number of microindels, some previously not reported. We also investigated the potential association of the identified Pfmrp2 polymorphisms with altered in vitro susceptibility to several antimalarials used in artemisinin-based combination therapy and with parasite clearance time. Association analysis suggested Pfmrp2 polymorphisms modulate the parasite's in vitro response to quinoline antimalarials, including chloroquine, piperaquine, and mefloquine, and association with in vivo parasite clearance. In conclusion, our study reveals that the Pfmrp2 gene is the most diverse ABC transporter known in P. falciparum with a potential role in antimalarial drug resistance. PMID:25267670

  5. 巴贝斯虫感染对宿主红细胞及免疫系统的影响%INFLUENCE OF BABESIA INFECTION ON HOST ERYTHROCYTES AND IMMUNE SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    魏金龙; 周金林

    2015-01-01

    巴贝斯虫(Babesia)是一种寄生于宿主红细胞的顶复门寄生虫,硬蜱为其传播媒介。由于巴贝斯虫感染后可以引起人或动物严重的临床症状,甚至造成死亡,给畜牧业和人类健康带来了极大威胁。本文主要综合国内外近年的研究成果,从巴贝斯虫入侵红细胞并对红细胞造成的影响,宿主感染后机体免疫状态的变化,以及共感染等方面进行综述,旨在为巴贝斯虫相关研究提供参考。%Babesia parasites are tick-transmitted intraerythrocytic protozoa of the phylum Apicomplexa, causing severe and even fatal disease and posing a great threaten for animal husbandry and human health. In this article, parasitic invasion to erythrocytes, changes of the host immune status after infection and aspects of co-infection are summarized according to the published results up to date. which will provide a reference for Babesia research.

  6. Purine salvage in the apicomplexan Sarcocystis neurona, and generation of hypoxanthine-xanthine-guanine phosphoribosyltransferase-deficient clones for positive-negative selection of transgenic parasites.

    Science.gov (United States)

    Dangoudoubiyam, Sriveny; Zhang, Zijing; Howe, Daniel K

    2014-09-01

    Sarcocystis neurona is an apicomplexan parasite that causes severe neurological disease in horses and marine mammals. The Apicomplexa are all obligate intracellular parasites that lack purine biosynthesis pathways and rely on the host cell for their purine requirements. Hypoxanthine-xanthine-guanine phosphoribosyltransferase (HXGPRT) and adenosine kinase (AK) are key enzymes that function in two complementary purine salvage pathways in apicomplexans. Bioinformatic searches of the S. neurona genome revealed genes encoding HXGPRT, AK and all of the major purine salvage enzymes except purine nucleoside phosphorylase. Wild-type S. neurona were able to grow in the presence of mycophenolic acid (MPA) but were inhibited by 6-thioxanthine (6-TX), suggesting that the pathways involving either HXGPRT or AK are functional in this parasite. Prior work with Toxoplasma gondii demonstrated the utility of HXGPRT as a positive-negative selection marker. To enable the use of HXGPRT in S. neurona, the SnHXGPRT gene sequence was determined and a gene-targeting plasmid was transfected into S. neurona. SnHXGPRT-deficient mutants were selected with 6-TX, and single-cell clones were obtained. These Sn∆HXG parasites were susceptible to MPA and could be complemented using the heterologous T. gondii HXGPRT gene. In summary, S. neurona possesses both purine salvage pathways described in apicomplexans, thus allowing the use of HXGPRT as a positive-negative drug selection marker in this parasite. PMID:24923662

  7. A novel family of Toxoplasma IMC proteins displays a hierarchical organization and functions in coordinating parasite division.

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    Josh R Beck

    Full Text Available Apicomplexans employ a peripheral membrane system called the inner membrane complex (IMC for critical processes such as host cell invasion and daughter cell formation. We have identified a family of proteins that define novel sub-compartments of the Toxoplasma gondii IMC. These IMC Sub-compartment Proteins, ISP1, 2 and 3, are conserved throughout the Apicomplexa, but do not appear to be present outside the phylum. ISP1 localizes to the apical cap portion of the IMC, while ISP2 localizes to a central IMC region and ISP3 localizes to a central plus basal region of the complex. Targeting of all three ISPs is dependent upon N-terminal residues predicted for coordinated myristoylation and palmitoylation. Surprisingly, we show that disruption of ISP1 results in a dramatic relocalization of ISP2 and ISP3 to the apical cap. Although the N-terminal region of ISP1 is necessary and sufficient for apical cap targeting, exclusion of other family members requires the remaining C-terminal region of the protein. This gate-keeping function of ISP1 reveals an unprecedented mechanism of interactive and hierarchical targeting of proteins to establish these unique sub-compartments in the Toxoplasma IMC. Finally, we show that loss of ISP2 results in severe defects in daughter cell formation during endodyogeny, indicating a role for the ISP proteins in coordinating this unique process of Toxoplasma replication.

  8. Unique apicomplexan IMC sub-compartment proteins are early markers for apical polarity in the malaria parasite

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    Benoit Poulin

    2013-09-01

    The phylum Apicomplexa comprises over 5000 intracellular protozoan parasites, including Plasmodium and Toxoplasma, that are clinically important pathogens affecting humans and livestock. Malaria parasites belonging to the genus Plasmodium possess a pellicle comprised of a plasmalemma and inner membrane complex (IMC, which is implicated in parasite motility and invasion. Using live cell imaging and reverse genetics in the rodent malaria model P. berghei, we localise two unique IMC sub-compartment proteins (ISPs and examine their role in defining apical polarity during zygote (ookinete development. We show that these proteins localise to the anterior apical end of the parasite where IMC organisation is initiated, and are expressed at all developmental stages, especially those that are invasive. Both ISP proteins are N-myristoylated, phosphorylated and membrane-bound. Gene disruption studies suggest that ISP1 is likely essential for parasite development, whereas ISP3 is not. However, an absence of ISP3 alters the apical localisation of ISP1 in all invasive stages including ookinetes and sporozoites, suggesting a coordinated function for these proteins in the organisation of apical polarity in the parasite.

  9. Structural Evidence for Actin-like Filaments in Toxoplasma gondii Using High-Resolution Low-Voltage Field Emission Scanning Electron Microscopy

    Science.gov (United States)

    Schatten, Heide; Sibley, L. David; Ris, Hans

    2003-08-01

    The protozoan parasite Toxoplasma gondii is representative of a large group of parasites within the phylum Apicomplexa, which share a highly unusual motility system that is crucial for locomotion and active host cell invasion. Despite the importance of motility in the pathology of these unicellular organisms, the motor mechanisms for locomotion remain uncertain, largely because only limited data exist about composition and organization of the cytoskeleton. By using cytoskeleton stabilizing protocols on membrane-extracted parasites and novel imaging with high-resolution low-voltage field emission scanning electron microscopy (LVFESEM), we were able to visualize for the first time a network of actin-sized filaments just below the cell membrane. A complex cytoskeletal network remained after removing the actin-sized fibers with cytochalasin D, revealing longitudinally arranged, subpellicular microtubules and intermediate-sized fibers of 10 nm, which, in stereo images, are seen both above and below the microtubules. These approaches open new possibilities to characterize more fully the largely unexplored and unconventional cytoskeletal motility complex in apicomplexan parasites.

  10. Towards a molecular understanding of the apicomplexan actin motor: on a road to novel targets for malaria remedies?

    International Nuclear Information System (INIS)

    In this review, current structural understanding of the apicomplexan glideosome and actin regulation is described. Apicomplexan parasites are the causative agents of notorious human and animal diseases that give rise to considerable human suffering and economic losses worldwide. The most prominent parasites of this phylum are the malaria-causing Plasmodium species, which are widespread in tropical and subtropical regions, and Toxoplasma gondii, which infects one third of the world’s population. These parasites share a common form of gliding motility which relies on an actin–myosin motor. The components of this motor and the actin-regulatory proteins in Apicomplexa have unique features compared with all other eukaryotes. This, together with the crucial roles of these proteins, makes them attractive targets for structure-based drug design. In recent years, several structures of glideosome components, in particular of actins and actin regulators from apicomplexan parasites, have been determined, which will hopefully soon allow the creation of a complete molecular picture of the parasite actin–myosin motor and its regulatory machinery. Here, current knowledge of the function of this motor is reviewed from a structural perspective

  11. Three-dimensional visualisation of developmental stages of an apicomplexan fish blood parasite in its invertebrate host

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    Hayes Polly M

    2011-11-01

    Full Text Available Abstract Background Although widely used in medicine, the application of three-dimensional (3D imaging to parasitology appears limited to date. In this study, developmental stages of a marine fish haemogregarine, Haemogregarina curvata (Apicomplexa: Adeleorina, were investigated in their leech vector, Zeylanicobdella arugamensis; this involved 3D visualisation of brightfield and confocal microscopy images of histological sections through infected leech salivary gland cells. Findings 3D assessment demonstrated the morphology of the haemogregarine stages, their spatial layout, and their relationship with enlarged host cells showing reduced cellular content. Haemogregarine meronts, located marginally within leech salivary gland cells, had small tail-like connections to the host cell limiting membrane; this parasite-host cell interface was not visible in two-dimensional (2D light micrographs and no records of a similar connection in apicomplexan development have been traced. Conclusions This is likely the first account of the use of 3D visualisation to study developmental stages of an apicomplexan parasite in its invertebrate vector. Elucidation of the extent of development of the haemogregarine within the leech salivary cells, together with the unusual connections between meronts and the host cell membrane, illustrates the future potential of 3D visualisation in parasite-vector biology.

  12. Species formation by host shifting in avian malaria parasites.

    Science.gov (United States)

    Ricklefs, Robert E; Outlaw, Diana C; Svensson-Coelho, Maria; Medeiros, Matthew C I; Ellis, Vincenzo A; Latta, Steven

    2014-10-14

    The malaria parasites (Apicomplexa: Haemosporida) of birds are believed to have diversified across the avian host phylogeny well after the origin of most major host lineages. Although many symbionts with direct transmission codiversify with their hosts, mechanisms of species formation in vector-borne parasites, including the role of host shifting, are poorly understood. Here, we examine the hosts of sister lineages in a phylogeny of 181 putative species of malaria parasites of New World terrestrial birds to determine the role of shifts between host taxa in the formation of new parasite species. We find that host shifting, often across host genera and families, is the rule. Sympatric speciation by host shifting would require local reproductive isolation as a prerequisite to divergent selection, but this mechanism is not supported by the generalized host-biting behavior of most vectors of avian malaria parasites. Instead, the geographic distribution of individual parasite lineages in diverse hosts suggests that species formation is predominantly allopatric and involves host expansion followed by local host-pathogen coevolution and secondary sympatry, resulting in local shifting of parasite lineages across hosts.

  13. Phylogenetic analysis of the genus Plasmodium based on the gene encoding adenylosuccinate lyase.

    Science.gov (United States)

    Kedzierski, Lukasz; Escalante, Ananias A; Isea, Raul; Black, Casilda G; Barnwell, John W; Coppel, Ross L

    2002-07-01

    Phylogenetic studies of the genus Plasmodium have been performed using sequences of the nuclear, mitochondrial and plastid genes. Here we have analyzed the adenylosuccinate lyase (ASL) gene, which encodes an enzyme involved in the salvage of host purines needed by malaria parasites for DNA synthesis. The ASL gene is present in several eukaryotic as well as prokaryotic organisms and does not have repeat regions, which facilitates the accuracy of the alignment. Furthermore, it has been shown that ASL is not subject to positive natural selection. We have sequenced the ASL gene of several different Plasmodium species infecting humans, rodents, monkeys and birds and used the obtained sequences along with the previously known P. falciparum ASL sequence, for structural and phylogenetic analysis of the genus Plasmodium. The genetic divergence of ASL is comparable with that observed in other nuclear genes such as cysteine proteinase, although ASL cannot be considered conserved when compared to aldolase or superoxide dismutase, which exhibit a slower rate of evolution. Nevertheless, a protein like ASL has a rate of evolution that provides enough information for elucidating evolutionary relationships. We modeled 3D structures of the ASL protein based on sequences used in the phylogenetic analysis and obtained a consistent structure for four different species despite the divergence observed. Such models would facilitate alignment in further studies with a greater number of plasmodial species or other Apicomplexa. PMID:12798008

  14. A transmission model for the ecology of an avian blood parasite in a temperate ecosystem.

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    Courtney C Murdock

    Full Text Available Most of our knowledge about avian haemosporidian parasites comes from the Hawaiian archipelago, where recently introduced Plasmodiumrelictum has contributed to the extinction of many endemic avian species. While the ecology of invasive malaria is reasonably understood, the ecology of endemic haemosporidian infection in mainland systems is poorly understood, even though it is the rule rather than the exception. We develop a mathematical model to explore and identify the ecological factors that most influence transmission of the common avian parasite, Leucocytozoonfringillinarum (Apicomplexa. The model was parameterized from White-crowned Sparrow (Zonotrichialeucophrys and S. silvestre / craigi black fly populations breeding in an alpine ecosystem. We identify and examine the importance of altricial nestlings, the seasonal relapse of infected birds for parasite persistence across breeding seasons, and potential impacts of seasonal changes in black fly emergence on parasite prevalence in a high elevation temperate system. We also use the model to identify and estimate the parameters most influencing transmission dynamics. Our analysis found that relapse of adult birds and young of the year birds were crucial for parasite persistence across multiple seasons. However, distinguishing between nude nestlings and feathered young of the year was unnecessary. Finally, due to model sensitivity to many black fly parameters, parasite prevalence and sparrow recruitment may be most affected by seasonal changes in environmental temperature driving shifts in black fly emergence and gonotrophic cycles.

  15. Complex polymorphisms in the Plasmodium falciparum multidrug resistance protein 2 gene and its contribution to antimalarial response.

    Science.gov (United States)

    Veiga, Maria Isabel; Osório, Nuno S; Ferreira, Pedro Eduardo; Franzén, Oscar; Dahlstrom, Sabina; Lum, J Koji; Nosten, Francois; Gil, José Pedro

    2014-12-01

    Plasmodium falciparum has the capacity to escape the actions of essentially all antimalarial drugs. ATP-binding cassette (ABC) transporter proteins are known to cause multidrug resistance in a large range of organisms, including the Apicomplexa parasites. P. falciparum genome analysis has revealed two genes coding for the multidrug resistance protein (MRP) type of ABC transporters: Pfmrp1, previously associated with decreased parasite drug susceptibility, and the poorly studied Pfmrp2. The role of Pfmrp2 polymorphisms in modulating sensitivity to antimalarial drugs has not been established. We herein report a comprehensive account of the Pfmrp2 genetic variability in 46 isolates from Thailand. A notably high frequency of 2.8 single nucleotide polymorphisms (SNPs)/kb was identified for this gene, including some novel SNPs. Additionally, we found that Pfmrp2 harbors a significant number of microindels, some previously not reported. We also investigated the potential association of the identified Pfmrp2 polymorphisms with altered in vitro susceptibility to several antimalarials used in artemisinin-based combination therapy and with parasite clearance time. Association analysis suggested Pfmrp2 polymorphisms modulate the parasite's in vitro response to quinoline antimalarials, including chloroquine, piperaquine, and mefloquine, and association with in vivo parasite clearance. In conclusion, our study reveals that the Pfmrp2 gene is the most diverse ABC transporter known in P. falciparum with a potential role in antimalarial drug resistance.

  16. Screening of potential targets in Plasmodium falciparum using stage-specific metabolic network analysis.

    Science.gov (United States)

    Dholakia, Neel; Dhandhukia, Pinakin; Roy, Nilanjan

    2015-11-01

    The Apicomplexa parasite Plasmodium is a major cause of death in developing countries which are less equipped to bring new medicines to the market. Currently available drugs used for treatment of malaria are limited either by inadequate efficacy, toxicity and/or increased resistance. Availability of the genome sequence, microarray data and metabolic profile of Plasmodium parasite offers an opportunity for the identification of stage-specific genes important to the organism's lifecycle. In this study, microarray data were analysed for differential expression and overlapped onto metabolic pathways to identify differentially regulated pathways essential for transition to successive erythrocytic stages. The results obtained indicate that S-adenosylmethionine decarboxylase/ornithine decarboxylase, a bifunctional enzyme required for polyamine synthesis, is important for the Plasmodium cell growth in the absence of exogenous polyamines. S-adenosylmethionine decarboxylase/ornithine decarboxylase is a valuable target for designing therapeutically useful inhibitors. One such inhibitor, [Formula: see text]-difluoromethyl ornithine, is currently in use for the treatment of African sleeping sickness caused by Trypanosoma brucei. Structural studies of ornithine decarboxylase along with known inhibitors and their analogues were carried out to screen drug databases for more effective and less toxic compounds.

  17. INFECCIÓN POR PROTOZOARIOS EN INDIVIDUOS DE TITÍ BEBE LECHE -S. fuscicollis-, TITÍ CABEZA BLANCA -S. oedipus-, TITÍ ARDILLA -S. sciureus-, SURICATO -S. suricatta- Y WALLABIE DE BENNETT -M. rufogriseus-: DESCRIPCIÓN DE CASOS

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    G. L. K. López

    2014-01-01

    Full Text Available La toxoplasmosis es una de las zoonosis parasitarias más comunes y de especial atención en medicina humana y veterinaria en todo el mundo. Toxoplasma gondii comparte mu - chos de sus parámetros biológicos con otros parásitos apicomplexa, pero es único por su extremadamente amplio rango de huéspedes y su especificidad tisular. La susceptibilidad en especies de primates del Nuevo Mundo y diprotodontos a la infección por protozoarios es alta. Bajo condiciones de cautiverio la toxoplasmosis es una de las infecciones más comunes en macrópodos australianos. En el presente trabajo se exponen los hallazgos clínicos y postmortem de 11 individuos de primates ( Saguinus oedipus, S. fuscicollis, Saimiri sciureus , carnívoros ( Suricata suricatta y diprotodontos ( Macropus rufogriseus , de la Fundación Zoológica de Cali, diagnosticados con toxoplasmosis mediante métodos paraclínicos e histopatológicos. En la mayoría de los casos el cuadro clínico se caracterizó principalmente por disnea, secreción nasal espumosa y signos neurológicos. Los hallazgos más importantes de la necropsia fueron lesiones en pulmón, hígado y encéfalo. Los casos aquí descritos corresponden a cuadros clínicos de ocurrencia natural y permiten entender el desarrollo fisiopatológico y la presentación clínica de las infecciones por protozoarios en especies de fauna silvestre, a pesar de la falta de un diagnóstico definitivo mediante técnicas específicas de inmunohistoquímica para las distintas etiologías.

  18. Phylogenetic Analysis of Nucleus-Encoded Acetyl-CoA Carboxylases Targeted at the Cytosol and Plastid of Algae.

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    Roger Huerlimann

    Full Text Available The understanding of algal phylogeny is being impeded by an unknown number of events of horizontal gene transfer (HGT, and primary and secondary/tertiary endosymbiosis. Through these events, previously heterotrophic eukaryotes developed photosynthesis and acquired new biochemical pathways. Acetyl-CoA carboxylase (ACCase is a key enzyme in the fatty acid synthesis and elongation pathways in algae, where ACCase exists in two locations (cytosol and plastid and in two forms (homomeric and heteromeric. All algae contain nucleus-encoded homomeric ACCase in the cytosol, independent of the origin of the plastid. Nucleus-encoded homomeric ACCase is also found in plastids of algae that arose from a secondary/tertiary endosymbiotic event. In contrast, plastids of algae that arose from a primary endosymbiotic event contain heteromeric ACCase, which consists of three nucleus-encoded and one plastid-encoded subunits. These properties of ACCase provide the potential to inform on the phylogenetic relationships of hosts and their plastids, allowing different hypothesis of endosymbiotic events to be tested. Alveolata (Dinoflagellata and Apicomplexa and Chromista (Stramenopiles, Haptophyta and Cryptophyta have traditionally been grouped together as Chromalveolata, forming the red lineage. However, recent genetic evidence groups the Stramenopiles, Alveolata and green plastid containing Rhizaria as SAR, excluding Haptophyta and Cryptophyta. Sequences coding for plastid and cytosol targeted homomeric ACCases were isolated from Isochrysis aff. galbana (TISO, Chromera velia and Nannochloropsis oculata, representing three taxonomic groups for which sequences were lacking. Phylogenetic analyses show that cytosolic ACCase strongly supports the SAR grouping. Conversely, plastidial ACCase groups the SAR with the Haptophyta, Cryptophyta and Prasinophyceae (Chlorophyta. These two ACCase based, phylogenetic relationships suggest that the plastidial homomeric ACCase was

  19. A survey of innovation through duplication in the reduced genomes of twelve parasites.

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    Jeremy D DeBarry

    Full Text Available We characterize the prevalence, distribution, divergence, and putative functions of detectable two-copy paralogs and segmental duplications in the Apicomplexa, a phylum of parasitic protists. Apicomplexans are mostly obligate intracellular parasites responsible for human and animal diseases (e.g. malaria and toxoplasmosis. Gene loss is a major force in the phylum. Genomes are small and protein-encoding gene repertoires are reduced. Despite this genomic streamlining, duplications and gene family amplifications are present. The potential for innovation introduced by duplications is of particular interest. We compared genomes of twelve apicomplexans across four lineages and used orthology and genome cartography to map distributions of duplications against genome architectures. Segmental duplications appear limited to five species. Where present, they correspond to regions enriched for multi-copy and species-specific genes, pointing toward roles in adaptation and innovation. We found a phylum-wide association of duplications with dynamic chromosome regions and syntenic breakpoints. Trends in the distribution of duplicated genes indicate that recent, species-specific duplicates are often tandem while most others have been dispersed by genome rearrangements. These trends show a relationship between genome architecture and gene duplication. Functional analysis reveals: proteases, which are vital to a parasitic lifecycle, to be prominent in putative recent duplications; a pair of paralogous genes in Toxoplasma gondii previously shown to produce the rate-limiting step in dopamine synthesis in mammalian cells, a possible link to the modification of host behavior; and phylum-wide differences in expression and subcellular localization, indicative of modes of divergence. We have uncovered trends in multiple modes of duplicate divergence including sequence, intron content, expression, subcellular localization, and functions of putative recent duplicates that

  20. Discovery of a Splicing Regulator Required for Cell Cycle Progression

    Energy Technology Data Exchange (ETDEWEB)

    Suvorova, Elena S.; Croken, Matthew; Kratzer, Stella; Ting, Li-Min; Conde de Felipe, Magnolia; Balu, Bharath; Markillie, Lye Meng; Weiss, Louis M.; Kim, Kami; White, Michael W.

    2013-02-01

    In the G1 phase of the cell division cycle, eukaryotic cells prepare many of the resources necessary for a new round of growth including renewal of the transcriptional and protein synthetic capacities and building the machinery for chromosome replication. The function of G1 has an early evolutionary origin and is preserved in single and multicellular organisms, although the regulatory mechanisms conducting G1 specific functions are only understood in a few model eukaryotes. Here we describe a new G1 mutant from an ancient family of apicomplexan protozoans. Toxoplasma gondii temperature-sensitive mutant 12-109C6 conditionally arrests in the G1 phase due to a single point mutation in a novel protein containing a single RNA-recognition-motif (TgRRM1). The resulting tyrosine to asparagine amino acid change in TgRRM1 causes severe temperature instability that generates an effective null phenotype for this protein when the mutant is shifted to the restrictive temperature. Orthologs of TgRRM1 are widely conserved in diverse eukaryote lineages, and the human counterpart (RBM42) can functionally replace the missing Toxoplasma factor. Transcriptome studies demonstrate that gene expression is downregulated in the mutant at the restrictive temperature due to a severe defect in splicing that affects both cell cycle and constitutively expressed mRNAs. The interaction of TgRRM1 with factors of the tri-SNP complex (U4/U6 & U5 snRNPs) indicate this factor may be required to assemble an active spliceosome. Thus, the TgRRM1 family of proteins is an unrecognized and evolutionarily conserved class of splicing regulators. This study demonstrates investigations into diverse unicellular eukaryotes, like the Apicomplexa, have the potential to yield new insights into important mechanisms conserved across modern eukaryotic kingdoms.

  1. Transcript and protein expression profile of PF11_0394, a Plasmodium falciparum protein expressed in salivary gland sporozoites

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    Schlarman Maggie S

    2012-03-01

    Full Text Available Abstract Background Plasmodium falciparum malaria is a significant problem around the world today, thus there is still a need for new control methods to be developed. Because the sporozoite displays dual infectivity for both the mosquito salivary glands and vertebrate host tissue, it is a good target for vaccine development. Methods The P. falciparum gene, PF11_0394, was chosen as a candidate for study due to its potential role in the invasion of host tissues. This gene, which was selected using a data mining approach from PlasmoDB, is expressed both at the transcriptional and protein levels in sporozoites and likely encodes a putative surface protein. Using reverse transcription-polymerase chain reaction (RT-PCR and green fluorescent protein (GFP-trafficking studies, a transcript and protein expression profile of PF11_0394 was determined. Results The PF11_0394 protein has orthologs in other Plasmodium species and Apicomplexans, but none outside of the group Apicomplexa. PF11_0394 transcript was found to be present during both the sporozoite and erythrocytic stages of the parasite life cycle, but no transcript was detected during axenic exoerythrocytic stages. Despite the presence of transcript throughout several life cycle stages, the PF11_0394 protein was only detected in salivary gland sporozoites. Conclusions PF11_0394 appears to be a protein uniquely detected in salivary gland sporozoites. Even though a specific function of PF11_0394 has not been determined in P. falciparum biology, it could be another candidate for a new vaccine.

  2. Comparative genome analysis reveals a conserved family of actin-like proteins in apicomplexan parasites

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    Sibley L David

    2005-12-01

    Full Text Available Abstract Background The phylum Apicomplexa is an early-branching eukaryotic lineage that contains a number of important human and animal pathogens. Their complex life cycles and unique cytoskeletal features distinguish them from other model eukaryotes. Apicomplexans rely on actin-based motility for cell invasion, yet the regulation of this system remains largely unknown. Consequently, we focused our efforts on identifying actin-related proteins in the recently completed genomes of Toxoplasma gondii, Plasmodium spp., Cryptosporidium spp., and Theileria spp. Results Comparative genomic and phylogenetic studies of apicomplexan genomes reveals that most contain only a single conventional actin and yet they each have 8–10 additional actin-related proteins. Among these are a highly conserved Arp1 protein (likely part of a conserved dynactin complex, and Arp4 and Arp6 homologues (subunits of the chromatin-remodeling machinery. In contrast, apicomplexans lack canonical Arp2 or Arp3 proteins, suggesting they lost the Arp2/3 actin polymerization complex on their evolutionary path towards intracellular parasitism. Seven of these actin-like proteins (ALPs are novel to apicomplexans. They show no phylogenetic associations to the known Arp groups and likely serve functions specific to this important group of intracellular parasites. Conclusion The large diversity of actin-like proteins in apicomplexans suggests that the actin protein family has diverged to fulfill various roles in the unique biology of intracellular parasites. Conserved Arps likely participate in vesicular transport and gene expression, while apicomplexan-specific ALPs may control unique biological traits such as actin-based gliding motility.

  3. Cats and Toxoplasma gondii: A systematic review and meta-analysis in Iran

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    Mohammad T. Rahimi

    2015-02-01

    Full Text Available Toxoplasma gondii is a cosmopolitan zoonotic intracellular coccidian of the phylum Apicomplexa infecting warm-blooded animals and human beings. This protozoan causes a significant public health problem in humans and imposes considerable economic losses and damages to husbandry industries. The final host, cats, accounts for all of these significant burdens. Hence the present study was designed to analyse and review the overall prevalence rate of T. gondii infection in cats in Iran for the first time. In the present study data collection (published and unpublished papers, abstracts of proceedings of national parasitology congresses and dissertations was systematically undertaken on electronic databases including PubMed, Google Scholar, Ebsco, Science Direct, Scopus, Magiran, Irandoc, IranMedex and Scientific Information Database. A total of 21 studies from 1975 to 2013 reporting prevalence of Toxoplasma infection in cats from different areas in Iran met the eligibility criteria. The pooled proportion of toxoplasmosis using the random-effect model amongst cats was estimated at 33.6% (95% confidence interval [CI] 22.05–46.41. The prevalence rate of cat toxoplasmosis in various regions of Iran ranged from 1.2% to 89.2%. Firstly, this study establishes a crude prevalence rate of T. gondii infection in cats. Secondly, it discusses the role of significant risk factors including sex, age and being either household or stray cats, in the epidemiology of the disease. Furthermore, the current study determines gaps and drawbacks in the prior studies that are useful to keep in mind to assist in designing more accurate investigations in future.

  4. Transcriptional Profiling of Chromera velia Under Diverse Environmental Conditions

    KAUST Repository

    Tayyrov, Annageldi

    2014-05-01

    Since its description in 2008, Chromera velia has drawn profound interest as the closest free-­‐living photosynthetic relative of apicomplexan parasites that are significant pathogens, causing enormous health and economic problems. There-­‐ fore, this newly described species holds a great potential to understand evolu-­‐ tionary basis of how photosynthetic algae evolved into the fully pathogenic Apicomplexa and how their common ancestors may have lived before they evolved into obligate parasites. Hence, the aim of this work is to understand how C. velia function and respond to different environmental conditions. This study aims to reveal how C. velia is able to respond to environmental perturbations that are applied individually and simultaneously since, studying stress factors in separation fails to elucidate complex responses to multi stress factors and un-­‐ derstanding the systemic regulation of involved genes. To extract biologically significant information and to identify genes involved in various physiological processes under variety of environmental conditions (i.e. a combination of vary-­‐ ing temperatures, iron availability, and salinity in the growth medium) we pre-­‐ pared strand specific RNA-­‐seq libraries for 83 samples in diverse environmental conditions. Here, we report the set of significantly differentially expressed genes as a re-­‐ sponse to the each condition and their combinations. Several interesting up-­‐ regulated and down-­‐regulated genes were found and their functions and in-­‐ volved pathways were studied. We showed that the profound regulation of HSP20 proteins is significant under stress conditions and hypothesized that the-­‐ se proteins might be involved in their movements.

  5. The mitochondrial genome of the entomoparasitic green alga helicosporidium.

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    Jean-François Pombert

    Full Text Available BACKGROUND: Helicosporidia are achlorophyllous, non-photosynthetic protists that are obligate parasites of invertebrates. Highly specialized, these pathogens feature an unusual cyst stage that dehisces inside the infected organism and releases a filamentous cell displaying surface projections, which will penetrate the host gut wall and eventually reproduce in the hemolymph. Long classified as incertae sedis or as relatives of other parasites such as Apicomplexa or Microsporidia, the Helicosporidia were surprisingly identified through molecular phylogeny as belonging to the Chlorophyta, a phylum of green algae. Most phylogenetic analyses involving Helicosporidia have placed them within the subgroup Trebouxiophyceae and further suggested a close affiliation between the Helicosporidia and the genus Prototheca. Prototheca species are also achlorophyllous and pathogenic, but they infect vertebrate hosts, inducing protothecosis in humans. The complete plastid genome of an Helicosporidium species was recently described and is a model of compaction and reduction. Here we describe the complete mitochondrial genome sequence of the same strain, Helicosporidium sp. ATCC 50920 isolated from the black fly Simulium jonesi. METHODOLOGY/PRINCIPAL FINDINGS: The circular mapping 49343 bp mitochondrial genome of Helicosporidium closely resembles that of the vertebrate parasite Prototheca wickerhamii. The two genomes share an almost identical gene complement and display a level of synteny that is higher than any other sequenced chlorophyte mitochondrial DNAs. Interestingly, the Helicosporidium mtDNA feature a trans-spliced group I intron, and a second group I intron that contains two open reading frames that appear to be degenerate maturase/endonuclease genes, both rare characteristics for this type of intron. CONCLUSIONS/SIGNIFICANCE: The architecture, genome content, and phylogeny of the Helicosporidium mitochondrial genome are all congruent with its close

  6. Export of a Toxoplasma gondii rhoptry neck protein complex at the host cell membrane to form the moving junction during invasion.

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    Sébastien Besteiro

    2009-02-01

    Full Text Available One of the most conserved features of the invasion process in Apicomplexa parasites is the formation of a moving junction (MJ between the apex of the parasite and the host cell membrane that moves along the parasite and serves as support to propel it inside the host cell. The MJ was, up to a recent period, completely unknown at the molecular level. Recently, proteins originated from two distinct post-Golgi specialised secretory organelles, the micronemes (for AMA1 and the neck of the rhoptries (for RON2/RON4/RON5 proteins, have been shown to form a complex. AMA1 and RON4 in particular, have been localised to the MJ during invasion. Using biochemical approaches, we have identified RON8 as an additional member of the complex. We also demonstrated that all RON proteins are present at the MJ during invasion. Using metabolic labelling and immunoprecipitation, we showed that RON2 and AMA1 were able to interact in the absence of the other members. We also discovered that all MJ proteins are subjected to proteolytic maturation during trafficking to their respective organelles and that they could associate as non-mature forms in vitro. Finally, whereas AMA1 has previously been shown to be inserted into the parasite membrane upon secretion, we demonstrated, using differential permeabilization and loading of RON-specific antibodies into the host cell, that the RON complex is targeted to the host cell membrane, where RON4/5/8 remain associated with the cytoplasmic face. Globally, these results point toward a model of MJ organization where the parasite would be secreting and inserting interacting components on either side of the MJ, both at the host and at its own plasma membranes.

  7. Identification of a novel and unique transcription factor in the intraerythrocytic stage of Plasmodium falciparum.

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    Kanako Komaki-Yasuda

    Full Text Available The mechanisms of stage-specific gene regulation in the malaria parasite Plasmodium falciparum are largely unclear, with only a small number of specific regulatory transcription factors (AP2 family having been identified. In particular, the transcription factors that function in the intraerythrocytic stage remain to be elucidated. Previously, as a model case for stage-specific transcription in the P. falciparum intraerythrocytic stage, we analyzed the transcriptional regulation of pf1-cys-prx, a trophozoite/schizont-specific gene, and suggested that some nuclear factors bind specifically to the cis-element of pf1-cys-prx and enhance transcription. In the present study, we purified nuclear factors from parasite nuclear extract by 5 steps of chromatography, and identified a factor termed PREBP. PREBP is not included in the AP2 family, and is a novel protein with four K-homology (KH domains. The KH domain is known to be found in RNA-binding or single-stranded DNA-binding proteins. PREBP is well conserved in Plasmodium species and partially conserved in phylum Apicomplexa. To evaluate the effects of PREBP overexpression, we used a transient overexpression and luciferase assay combined approach. Overexpression of PREBP markedly enhanced luciferase expression under the control of the pf1-cys-prx cis-element. These results provide the first evidence of a novel transcription factor that activates the gene expression in the malaria parasite intraerythrocytic stage. These findings enhance our understanding of the evolution of specific transcription machinery in Plasmodium and other eukaryotes.

  8. Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum.

    Science.gov (United States)

    Teixeira, Luzia; Moreira, João; Melo, Joana; Bezerra, Filipa; Marques, Raquel M; Ferreirinha, Pedro; Correia, Alexandra; Monteiro, Mariana P; Ferreira, Paula G; Vilanova, Manuel

    2015-06-01

    The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet(+) cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-γ was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue.

  9. Microscopic and molecular studies of the diversity of free-living protozoa in meat-cutting plants.

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    Vaerewijck, Mario J M; Sabbe, Koen; Baré, Julie; Houf, Kurt

    2008-09-01

    The diversity of free-living protozoa in five meat-cutting plants was determined. Light microscopy after enrichment culturing was combined with sequencing of PCR-amplified, denaturing gradient gel electrophoresis (DGGE)-separated 18S rRNA gene fragments, which was used as a fast screening method. The general results of the survey showed that a protozoan community of amoebae, ciliates, and flagellates was present in all of the plants. Protozoa were detected mainly in floor drains, in standing water on the floor, on soiled bars of cutting tables, on plastic pallets, and in out-of-use hot water knife sanitizers, but they were also detected on surfaces which come into direct contact with meat, such as conveyer belts, working surfaces of cutting tables, and needles of a meat tenderizer. After 7 days of incubation at refrigerator temperature, protozoa were detected in about one-half of the enrichment cultures. Based on microscopic observations, 61 morphospecies were found, and Bodo saltans, Bodo spp., Epistylis spp., Glaucoma scintillans, Petalomonas spp., Prodiscophrya collini, and Vannella sp. were the most frequently encountered identified organisms. Sequencing of DGGE bands resulted in identification of a total of 49 phylotypes, including representatives of the Amoebozoa, Chromalveolata, Excavata, Opisthokonta, and Rhizaria. Sequences of small heterotrophic flagellates were affiliated mainly with the Alveolata (Apicomplexa), Stramenopiles (Chrysophyceae), and Rhizaria (Cercozoa). This survey showed that there is high protozoan species richness in meat-cutting plants and that the species included species related to known hosts of food-borne pathogens. PMID:18641165

  10. Microscopic and Molecular Studies of the Diversity of Free-Living Protozoa in Meat-Cutting Plants▿

    Science.gov (United States)

    Vaerewijck, Mario J. M.; Sabbe, Koen; Baré, Julie; Houf, Kurt

    2008-01-01

    The diversity of free-living protozoa in five meat-cutting plants was determined. Light microscopy after enrichment culturing was combined with sequencing of PCR-amplified, denaturing gradient gel electrophoresis (DGGE)-separated 18S rRNA gene fragments, which was used as a fast screening method. The general results of the survey showed that a protozoan community of amoebae, ciliates, and flagellates was present in all of the plants. Protozoa were detected mainly in floor drains, in standing water on the floor, on soiled bars of cutting tables, on plastic pallets, and in out-of-use hot water knife sanitizers, but they were also detected on surfaces which come into direct contact with meat, such as conveyer belts, working surfaces of cutting tables, and needles of a meat tenderizer. After 7 days of incubation at refrigerator temperature, protozoa were detected in about one-half of the enrichment cultures. Based on microscopic observations, 61 morphospecies were found, and Bodo saltans, Bodo spp., Epistylis spp., Glaucoma scintillans, Petalomonas spp., Prodiscophrya collini, and Vannella sp. were the most frequently encountered identified organisms. Sequencing of DGGE bands resulted in identification of a total of 49 phylotypes, including representatives of the Amoebozoa, Chromalveolata, Excavata, Opisthokonta, and Rhizaria. Sequences of small heterotrophic flagellates were affiliated mainly with the Alveolata (Apicomplexa), Stramenopiles (Chrysophyceae), and Rhizaria (Cercozoa). This survey showed that there is high protozoan species richness in meat-cutting plants and that the species included species related to known hosts of food-borne pathogens. PMID:18641165

  11. The unique adaptation of the life cycle of the coelomic gregarine Diplauxis hatti to its host Perinereis cultrifera (Annelida, Polychaeta): an experimental and ultrastructural study.

    Science.gov (United States)

    Prensier, Gerard; Dubremetz, Jean-Francois; Schrevel, Joseph

    2008-01-01

    The coelomic gregarine Diplauxis hatti exhibits a unique adaptation of its life cycle to its polychaete host Perinereis cultrifera. Experimental and ultrastructural observations on natural populations from the English Channel showed that release of parasite spores is concomitant with the polychaete spawning. As the development of P. cultrifera is direct, the notochete larva ingest parts of the jelly coat covered with numerous sporocysts of D. hatti during hatching. Transepithelial migration of the sporozoites takes place in the gut of three- or four-segment notochete larvae and syzygies of about 20 microm are observed in the coelom. Growth of these young syzygies is slow: after 18-24 mo they reach only 60-70 microm. They exhibit active pendular movements. In the English Channel, female and male gametogenesis of P. cultrifera begins at 19 mo and 2 yr, respectively; the somatic transformations (epitoky) in the last 4 mo of their 3-year life. During epitoky, the syzygies undergo an impressive growth and reach 700-800 microm within a few weeks. A shift from pendular to active peristaltic motility is observed when the syzygies reach 200-250 microm. When gamogony occurs, syncytial nuclear divisions are initiated and cellularization produces hundred to thousands of male and female gametes of similar size. The male gametes exhibit a flagellum with 3+0 axoneme. The mixing of the gametes ("danse des gametes") and fertilization are observed during 4-5 h. Zygotes differentiate sporoblasts with eight sporozoites. The sporozoites exhibit the canonical structure of Apicomplexa, a polarized cell with micronemes and rhoptries. PMID:19120801

  12. Gene gain and loss during evolution of obligate parasitism in the white rust pathogen of Arabidopsis thaliana.

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    Eric Kemen

    2011-07-01

    Full Text Available Biotrophic eukaryotic plant pathogens require a living host for their growth and form an intimate haustorial interface with parasitized cells. Evolution to biotrophy occurred independently in fungal rusts and powdery mildews, and in oomycete white rusts and downy mildews. Biotroph evolution and molecular mechanisms of biotrophy are poorly understood. It has been proposed, but not shown, that obligate biotrophy results from (i reduced selection for maintenance of biosynthetic pathways and (ii gain of mechanisms to evade host recognition or suppress host defence. Here we use Illumina sequencing to define the genome, transcriptome, and gene models for the obligate biotroph oomycete and Arabidopsis parasite, Albugo laibachii. A. laibachii is a member of the Chromalveolata, which incorporates Heterokonts (containing the oomycetes, Apicomplexa (which includes human parasites like Plasmodium falciparum and Toxoplasma gondii, and four other taxa. From comparisons with other oomycete plant pathogens and other chromalveolates, we reveal independent loss of molybdenum-cofactor-requiring enzymes in downy mildews, white rusts, and the malaria parasite P. falciparum. Biotrophy also requires "effectors" to suppress host defence; we reveal RXLR and Crinkler effectors shared with other oomycetes, and also discover and verify a novel class of effectors, the "CHXCs", by showing effector delivery and effector functionality. Our findings suggest that evolution to progressively more intimate association between host and parasite results in reduced selection for retention of certain biosynthetic pathways, and particularly reduced selection for retention of molybdopterin-requiring biosynthetic pathways. These mechanisms are not only relevant to plant pathogenic oomycetes but also to human pathogens within the Chromalveolata.

  13. Responses of soil microeukaryotic communities to short-term fumigation-incubation revealed by MiSeq amplicon sequencing

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    Lin eChen

    2015-10-01

    Full Text Available In soil microbiology, there is a ‘paradox’ of soil organic carbon (SOC mineralization, which is that even though chloroform fumigation destroys majority of the soil microbial biomass, SOC mineralization continues at the same rate as in the non-fumigated soil during the incubation period. Soil microeukaryotes as important SOC decomposers, however, their community-level responses to chloroform fumigation are not well understood. Using the 18S rRNA gene amplicon sequencing, we analyzed the composition, diversity and C-metabolic functions of a grassland soil and an arable soil microeukaryotic community in response to fumigation followed by a 30-day incubation. The grassland and arable soil microeukaryotic communities were dominated by the fungal Ascomycota (80.5–93.1% of the fungal sequences, followed by the protistan Cercozoa and Apicomplexa. In the arable soil fungal community, the predominance of the class Sordariomycetes was replaced by the class Eurotiomycetes after fumigation at days 7 and 30 of the incubation. Fumigation changed the microeukaryotic α-diversity in the grassland soil at days 0 and 7, and β-diversity in the arable soil at days 7 and 30. Network analysis indicated that after fumigation fungi were important groups closely related to other taxa. Most phylotypes (especially Sordariomycetes, Dothideomycetes, Coccidia and uncultured Chytridiomycota were inhibited, and only a few were positively stimulated by fumigation. Despite the inhibited Sordariomycetes, the fumigated communities mainly consisted of Eurotiomycetes and Sordariomycetes (21.9% and 36.5% relative frequency, respectively, which are able to produce hydrolytic enzymes associated with SOC mineralization. Our study suggests that fumigation not only decreases biomass size, but modulates the composition and diversity of the soil microeukaryotic communities, which are capable of driving SOC mineralization by release of hydrolytic enzymes during short-term fumigation-incubation.

  14. Comparative genomics of the apicomplexan parasites Toxoplasma gondii and neospora caninum: Coccidia differing in host range and transmission strategy

    KAUST Repository

    Reid, Adam James

    2012-03-22

    Toxoplasma gondii is a zoonotic protozoan parasite which infects nearly one third of the human population and is found in an extraordinary range of vertebrate hosts. Its epidemiology depends heavily on horizontal transmission, especially between rodents and its definitive host, the cat. Neospora caninum is a recently discovered close relative of Toxoplasma, whose definitive host is the dog. Both species are tissue-dwelling Coccidia and members of the phylum Apicomplexa; they share many common features, but Neospora neither infects humans nor shares the same wide host range as Toxoplasma, rather it shows a striking preference for highly efficient vertical transmission in cattle. These species therefore provide a remarkable opportunity to investigate mechanisms of host restriction, transmission strategies, virulence and zoonotic potential. We sequenced the genome of N. caninum and transcriptomes of the invasive stage of both species, undertaking an extensive comparative genomics and transcriptomics analysis. We estimate that these organisms diverged from their common ancestor around 28 million years ago and find that both genomes and gene expression are remarkably conserved. However, in N. caninum we identified an unexpected expansion of surface antigen gene families and the divergence of secreted virulence factors, including rhoptry kinases. Specifically we show that the rhoptry kinase ROP18 is pseudogenised in N. caninum and that, as a possible consequence, Neospora is unable to phosphorylate host immunity-related GTPases, as Toxoplasma does. This defense strategy is thought to be key to virulence in Toxoplasma. We conclude that the ecological niches occupied by these species are influenced by a relatively small number of gene products which operate at the host-parasite interface and that the dominance of vertical transmission in N. caninum may be associated with the evolution of reduced virulence in this species.

  15. Phylogenetic Analysis of Nucleus-Encoded Acetyl-CoA Carboxylases Targeted at the Cytosol and Plastid of Algae.

    KAUST Repository

    Huerlimann, Roger

    2015-07-01

    The understanding of algal phylogeny is being impeded by an unknown number of events of horizontal gene transfer (HGT), and primary and secondary/tertiary endosymbiosis. Through these events, previously heterotrophic eukaryotes developed photosynthesis and acquired new biochemical pathways. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the fatty acid synthesis and elongation pathways in algae, where ACCase exists in two locations (cytosol and plastid) and in two forms (homomeric and heteromeric). All algae contain nucleus-encoded homomeric ACCase in the cytosol, independent of the origin of the plastid. Nucleus-encoded homomeric ACCase is also found in plastids of algae that arose from a secondary/tertiary endosymbiotic event. In contrast, plastids of algae that arose from a primary endosymbiotic event contain heteromeric ACCase, which consists of three nucleus-encoded and one plastid-encoded subunits. These properties of ACCase provide the potential to inform on the phylogenetic relationships of hosts and their plastids, allowing different hypothesis of endosymbiotic events to be tested. Alveolata (Dinoflagellata and Apicomplexa) and Chromista (Stramenopiles, Haptophyta and Cryptophyta) have traditionally been grouped together as Chromalveolata, forming the red lineage. However, recent genetic evidence groups the Stramenopiles, Alveolata and green plastid containing Rhizaria as SAR, excluding Haptophyta and Cryptophyta. Sequences coding for plastid and cytosol targeted homomeric ACCases were isolated from Isochrysis aff. galbana (TISO), Chromera velia and Nannochloropsis oculata, representing three taxonomic groups for which sequences were lacking. Phylogenetic analyses show that cytosolic ACCase strongly supports the SAR grouping. Conversely, plastidial ACCase groups the SAR with the Haptophyta, Cryptophyta and Prasinophyceae (Chlorophyta). These two ACCase based, phylogenetic relationships suggest that the plastidial homomeric ACCase was acquired by the

  16. Identification of putative cis-regulatory elements in Cryptosporidium parvum by de novo pattern finding

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    Kissinger Jessica C

    2007-01-01

    Full Text Available Abstract Background Cryptosporidium parvum is a unicellular eukaryote in the phylum Apicomplexa. It is an obligate intracellular parasite that causes diarrhea and is a significant AIDS-related pathogen. Cryptosporidium parvum is not amenable to long-term laboratory cultivation or classical molecular genetic analysis. The parasite exhibits a complex life cycle, a broad host range, and fundamental mechanisms of gene regulation remain unknown. We have used data from the recently sequenced genome of this organism to uncover clues about gene regulation in C. parvum. We have applied two pattern finding algorithms MEME and AlignACE to identify conserved, over-represented motifs in the 5' upstream regions of genes in C. parvum. To support our findings, we have established comparative real-time -PCR expression profiles for the groups of genes examined computationally. Results We find that groups of genes that share a function or belong to a common pathway share upstream motifs. Different motifs are conserved upstream of different groups of genes. Comparative real-time PCR studies show co-expression of genes within each group (in sub-sets during the life cycle of the parasite, suggesting co-regulation of these genes may be driven by the use of conserved upstream motifs. Conclusion This is one of the first attempts to characterize cis-regulatory elements in the absence of any previously characterized elements and with very limited expression data (seven genes only. Using de novo pattern finding algorithms, we have identified specific DNA motifs that are conserved upstream of genes belonging to the same metabolic pathway or gene family. We have demonstrated the co-expression of these genes (often in subsets using comparative real-time-PCR experiments thus establishing evidence for these conserved motifs as putative cis-regulatory elements. Given the lack of prior information concerning expression patterns and organization of promoters in C. parvum we

  17. The evolutionary history of sarco(endoplasmic calcium ATPase (SERCA.

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    Ianina Altshuler

    Full Text Available Investigating the phylogenetic relationships within physiologically essential gene families across a broad range of taxa can reveal the key gene duplication events underlying their family expansion and is thus important to functional genomics studies. P-Type II ATPases represent a large family of ATP powered transporters that move ions across cellular membranes and includes Na(+/K(+ transporters, H(+/K(+ transporters, and plasma membrane Ca(2+ pumps. Here, we examine the evolutionary history of one such transporter, the Sarco(endoplasmic reticulum calcium ATPase (SERCA, which maintains calcium homeostasis in the cell by actively pumping Ca(2+ into the sarco(endoplasmic reticulum. Our protein-based phylogenetic analyses across Eukaryotes revealed two monophyletic clades of SERCA proteins, one containing animals, fungi, and plants, and the other consisting of plants and protists. Our analyses suggest that the three known SERCA proteins in vertebrates arose through two major gene duplication events after the divergence from tunicates, but before the separation of fishes and tetrapods. In plants, we recovered two SERCA clades, one being the sister group to Metazoa and the other to Apicomplexa clade, suggesting an ancient duplication in an early eukaryotic ancestor, followed by subsequent loss of one copy in Opisthokonta, the other in protists, and retention of both in plants. We also report relatively recent and independent gene duplication events within invertebrate taxa including tunicates and the leech Helobdella robusta. Thus, it appears that both ancient and recent gene duplication events have played an important role in the evolution of this ubiquitous gene family across the eukaryotic domain.

  18. Cryptic Eimeria genotypes are common across the southern but not northern hemisphere.

    Science.gov (United States)

    Clark, Emily L; Macdonald, Sarah E; Thenmozhi, V; Kundu, Krishnendu; Garg, Rajat; Kumar, Saroj; Ayoade, Simeon; Fornace, Kimberly M; Jatau, Isa Danladi; Moftah, Abdalgader; Nolan, Matthew J; Sudhakar, N R; Adebambo, A O; Lawal, I A; Álvarez Zapata, Ramón; Awuni, Joseph A; Chapman, H David; Karimuribo, Esron; Mugasa, Claire M; Namangala, Boniface; Rushton, Jonathan; Suo, Xun; Thangaraj, Kumarasamy; Srinivasa Rao, Arni S R; Tewari, Anup K; Banerjee, Partha S; Dhinakar Raj, G; Raman, M; Tomley, Fiona M; Blake, Damer P

    2016-08-01

    The phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp. cause intestinal coccidiosis in all major livestock animals and are the most important parasites of domestic chickens in terms of both economic impact and animal welfare. Despite having significant negative impacts on the efficiency of food production, many fundamental questions relating to the global distribution and genetic variation of Eimeria spp. remain largely unanswered. Here, we provide the broadest map yet of Eimeria occurrence for domestic chickens, confirming that all the known species (Eimeria acervulina, Eimeria brunetti, Eimeria maxima, Eimeria mitis, Eimeria necatrix, Eimeria praecox, Eimeria tenella) are present in all six continents where chickens are found (including 21 countries). Analysis of 248 internal transcribed spacer sequences derived from 17 countries provided evidence of possible allopatric diversity for species such as E. tenella (FST values ⩽0.34) but not E. acervulina and E. mitis, and highlighted a trend towards widespread genetic variance. We found that three genetic variants described previously only in Australia and southern Africa (operational taxonomic units x, y and z) have a wide distribution across the southern, but not the northern hemisphere. While the drivers for such a polarised distribution of these operational taxonomic unit genotypes remains unclear, the occurrence of genetically variant Eimeria may pose a risk to food security and animal welfare in Europe and North America should these parasites spread to the northern hemisphere. PMID:27368611

  19. Basal body structure and composition in the apicomplexans Toxoplasma and Plasmodium.

    Science.gov (United States)

    Francia, Maria E; Dubremetz, Jean-Francois; Morrissette, Naomi S

    2015-01-01

    The phylum Apicomplexa encompasses numerous important human and animal disease-causing parasites, including the Plasmodium species, and Toxoplasma gondii, causative agents of malaria and toxoplasmosis, respectively. Apicomplexans proliferate by asexual replication and can also undergo sexual recombination. Most life cycle stages of the parasite lack flagella; these structures only appear on male gametes. Although male gametes (microgametes) assemble a typical 9+2 axoneme, the structure of the templating basal body is poorly defined. Moreover, the relationship between asexual stage centrioles and microgamete basal bodies remains unclear. While asexual stages of Plasmodium lack defined centriole structures, the asexual stages of Toxoplasma and closely related coccidian apicomplexans contain centrioles that consist of nine singlet microtubules and a central tubule. There are relatively few ultra-structural images of Toxoplasma microgametes, which only develop in cat intestinal epithelium. Only a subset of these include sections through the basal body: to date, none have unambiguously captured organization of the basal body structure. Moreover, it is unclear whether this basal body is derived from pre-existing asexual stage centrioles or is synthesized de novo. Basal bodies in Plasmodium microgametes are thought to be synthesized de novo, and their assembly remains ill-defined. Apicomplexan genomes harbor genes encoding δ- and ε-tubulin homologs, potentially enabling these parasites to assemble a typical triplet basal body structure. Moreover, the UNIMOD components (SAS6, SAS4/CPAP, and BLD10/CEP135) are conserved in these organisms. However, other widely conserved basal body and flagellar biogenesis elements are missing from apicomplexan genomes. These differences may indicate variations in flagellar biogenesis pathways and in basal body arrangement within the phylum. As apicomplexan basal bodies are distinct from their metazoan counterparts, it may be possible to

  20. Characterisation and expression of a PP1 serine/threonine protein phosphatase (PfPP1 from the malaria parasite, Plasmodium falciparum: demonstration of its essential role using RNA interference

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    Musiyenko Alla

    2002-04-01

    Full Text Available Abstract Background Reversible protein phosphorylation is relatively unexplored in the intracellular protozoa of the Apicomplexa family that includes the genus Plasmodium, to which belong the causative agents of malaria. Members of the PP1 family represent the most highly conserved protein phosphatase sequences in phylogeny and play essential regulatory roles in various cellular pathways. Previous evidence suggested a PP1-like activity in Plasmodium falciparum, not yet identified at the molecular level. Results We have identified a PP1 catalytic subunit from P. falciparum and named it PfPP1. The predicted primary structure of the 304-amino acid long protein was highly similar to PP1 sequences of other species, and showed conservation of all the signature motifs. The purified recombinant protein exhibited potent phosphatase activity in vitro. Its sensitivity to specific phosphatase inhibitors was characteristic of the PP1 class. The authenticity of the PfPP1 cDNA was further confirmed by mutational analysis of strategic amino acid residues important in catalysis. The protein was expressed in all erythrocytic stages of the parasite. Abrogation of PP1 expression by synthetic short interfering RNA (siRNA led to inhibition of parasite DNA synthesis. Conclusions The high sequence similarity of PfPP1 with other PP1 members suggests conservation of function. Phenotypic gene knockdown studies using siRNA confirmed its essential role in the parasite. Detailed studies of PfPP1 and its regulation may unravel the role of reversible protein phosphorylation in the signalling pathways of the parasite, including glucose metabolism and parasitic cell division. The use of siRNA could be an important tool in the functional analysis of Apicomplexan genes.

  1. Effects of ionizing radiation over the structure, metabolism and infectivity of a pathogenic protozoan, Toxoplasma gondii; Efeitos da radiacao ionizante sobre a estrutura, metabolismo e infectividade de um protozoario patogenico, Toxoplasma gondii (Nicole and Manceau, 1908)

    Energy Technology Data Exchange (ETDEWEB)

    Hiramoto, Roberto Mitsuyoshi

    1998-07-01

    The intracellular parasite Toxoplasma gondii (Apicomplexa), has as definitive host domestic and wild felines and as intermediate hosts most species of mammals and birds, Including man. The infection in man is usually asymptomatic, but can become a severe and lethal illness in some special groups like the fetus of primoinfected pregnant woman, or in AIDS and transplanted patients. The transmission is due to ingestion of food or water contaminated with oocysts from cat feces as well as raw or rare cooked cyst containing meet. There is no available vaccine against toxoplasmosis, with some reports of the use ionizing radiation in order to attenuate or suppress the parasite. These studies are promising, but more research is needed to optimize the radiation process and to clarify those alterations caused on T gondii.Using a increasing doses of {sup 60} Co irradiation on T.gondii tachyzoites, we studied many parameters such as morphology, both at optical and electron microscopy level, detection of DNA fragmentation, metabolism alterations (cellular oxidative burst, protein, nucleic acids and DNA synthesis), determination of the parasite survival both in in vivo and in vitro models, antigenicity and immunogenicity after the process, cellular invasion and irradiated tachyzoite induced protection. After definition of 200 Gy of {sup 60} Co irradiation as the lower radiation dose that suppress parasite growth in vitro and in vivo, we found no detectable changes in parasite viability, its cell invasion capacity or in its structural proteins. DNA fragmentation like apoptosis or alterations of the parasite metabolism were similarly not affected by radiation. Mice infection with irradiated parasites induce partial protection when these animals were re-inoculated with non irradiated virulent parasites, inducing greater specific IgG levels as well as a longer survival. Irradiated T.gondii maintains its the ability of invasion, even under radiation effects. Based on our results we

  2. PvRON2, a new Plasmodium vivax rhoptry neck antigen

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    Curtidor Hernando

    2011-03-01

    Full Text Available Abstract Background Rhoptries are specialized organelles from parasites belonging to the phylum Apicomplexa; they secrete their protein content during invasion of host target cells and are sorted into discrete subcompartments within rhoptry neck or bulb. This distribution is associated with these proteins' role in tight junction (TJ and parasitophorous vacuole (PV formation, respectively. Methods Plasmodium falciparum RON2 amino acid sequence was used as bait for screening the codifying gene for the homologous protein in the Plasmodium vivax genome. Gene synteny, as well as identity and similarity values, were determined for ron2 and its flanking genes among P. falciparum, P. vivax and other malarial parasite genomes available at PlasmoDB and Sanger Institute databases. Pvron2 gene transcription was determined by RT-PCR of cDNA obtained from the P. vivax VCG-1 strain. Protein expression and localization were assessed by Western blot and immunofluorescence using polyclonal anti-PvRON2 antibodies. Co-localization was confirmed using antibodies directed towards specific microneme and rhoptry neck proteins. Results and discussion The first P. vivax rhoptry neck protein (named here PvRON2 has been identified in this study. PvRON2 is a 2,204 residue-long protein encoded by a single 6,615 bp exon containing a hydrophobic signal sequence towards the amino-terminus, a transmembrane domain towards the carboxy-terminus and two coiled coil α-helical motifs; these are characteristic features of several previously described vaccine candidates against malaria. This protein also contains two tandem repeats within the interspecies variable sequence possibly involved in evading a host's immune system. PvRON2 is expressed in late schizonts and localized in rhoptry necks similar to what has been reported for PfRON2, which suggests its participation during target cell invasion. Conclusions The identification and partial characterization of the first P. vivax

  3. Properties of non-coding DNA and identification of putative cis-regulatory elements in Theileria parva

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    Guo Xiang

    2008-12-01

    regulatory motifs in other species. These results suggest that these two motifs are likely to represent transcription factor binding sites in Theileria. Conclusion Theileria genomes are highly compact, with selection seemingly favoring short introns and intergenic regions. Three over-represented sequence motifs were independently identified in intergenic regions of both Theileria species, and the evidence suggests that at least two of them play a role in transcriptional control in T. parva. These are prime candidates for experimental validation of transcription factor binding sites in this single-celled eukaryotic parasite. Sequences similar to two of these Theileria motifs are conserved in Plasmodium hinting at the possibility of common regulatory machinery across the phylum Apicomplexa.

  4. Consistent and contrasting properties of lineage-specific genes in the apicomplexan parasites Plasmodium and Theileria

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    Kissinger Jessica C

    2008-04-01

    Full Text Available Abstract Background Lineage-specific genes, the genes that are restricted to a limited subset of related organisms, may be important in adaptation. In parasitic organisms, lineage-specific gene products are possible targets for vaccine development or therapeutics when these genes are absent from the host genome. Results In this study, we utilized comparative approaches based on a phylogenetic framework to characterize lineage-specific genes in the parasitic protozoan phylum Apicomplexa. Genes from species in two major apicomplexan genera, Plasmodium and Theileria, were categorized into six levels of lineage specificity based on a nine-species phylogeny. In both genera, lineage-specific genes tend to have a higher level of sequence divergence among sister species. In addition, species-specific genes possess a strong codon usage bias compared to other genes in the genome. We found that a large number of genus- or species-specific genes are putative surface antigens that may be involved in host-parasite interactions. Interestingly, the two parasite lineages exhibit several notable differences. In Plasmodium, the (G + C content at the third codon position increases with lineage specificity while Theileria shows the opposite trend. Surface antigens in Plasmodium are species-specific and mainly located in sub-telomeric regions. In contrast, surface antigens in Theileria are conserved at the genus level and distributed across the entire lengths of chromosomes. Conclusion Our results provide further support for the model that gene duplication followed by rapid divergence is a major mechanism for generating lineage-specific genes. The result that many lineage-specific genes are putative surface antigens supports the hypothesis that lineage-specific genes could be important in parasite adaptation. The contrasting properties between the lineage-specific genes in two major apicomplexan genera indicate that the mechanisms of generating lineage-specific genes

  5. ApiAP2 Factors as Candidate Regulators of Stochastic Commitment to Merozoite Production in Theileria annulata.

    Directory of Open Access Journals (Sweden)

    Marta Pieszko

    Apicomplexa; leading to the proposal that the mechanisms that control stage differentiation will show a degree of conservation.

  6. Effects of ionizing radiation over the structure, metabolism and infectivity of a pathogenic protozoan, Toxoplasma gondii

    International Nuclear Information System (INIS)

    The intracellular parasite Toxoplasma gondii (Apicomplexa), has as definitive host domestic and wild felines and as intermediate hosts most species of mammals and birds, Including man. The infection in man is usually asymptomatic, but can become a severe and lethal illness in some special groups like the fetus of primoinfected pregnant woman, or in AIDS and transplanted patients. The transmission is due to ingestion of food or water contaminated with oocysts from cat feces as well as raw or rare cooked cyst containing meet. There is no available vaccine against toxoplasmosis, with some reports of the use ionizing radiation in order to attenuate or suppress the parasite. These studies are promising, but more research is needed to optimize the radiation process and to clarify those alterations caused on T gondii.Using a increasing doses of 60 Co irradiation on T.gondii tachyzoites, we studied many parameters such as morphology, both at optical and electron microscopy level, detection of DNA fragmentation, metabolism alterations (cellular oxidative burst, protein, nucleic acids and DNA synthesis), determination of the parasite survival both in in vivo and in vitro models, antigenicity and immunogenicity after the process, cellular invasion and irradiated tachyzoite induced protection. After definition of 200 Gy of 60 Co irradiation as the lower radiation dose that suppress parasite growth in vitro and in vivo, we found no detectable changes in parasite viability, its cell invasion capacity or in its structural proteins. DNA fragmentation like apoptosis or alterations of the parasite metabolism were similarly not affected by radiation. Mice infection with irradiated parasites induce partial protection when these animals were re-inoculated with non irradiated virulent parasites, inducing greater specific IgG levels as well as a longer survival. Irradiated T.gondii maintains its the ability of invasion, even under radiation effects. Based on our results we conclude that

  7. Morphological and molecular characterization of Isospora manorinae n. sp. in a yellow-throated miner (Manorina flavigula wayensis) (Gould, 1840).

    Science.gov (United States)

    Yang, Rongchang; Brice, Belinda; Jian, Fuchun; Ryan, Una

    2016-04-01

    A new Isospora (Apicomplexa:Eimeriidae) species is described from a single yellow-throated miner bird (Manorina flavigula) (subspecies M. f. wayensis) in Western Australia. Sporulated oocysts (n = 32) of this isolate are spherical to subspherical, 22.8 (20.3-23.8) × 18.3 (17.7-18.7) μm, with a shape index (length/width) of 1.25 (1.2-1.3); and a smooth and bilayered oocyst wall, 1.3 μm thick (outer layer 0.9 μm, inner 0.4 μm). A polar granule is present, but the micropyle and oocyst residuum are absent. The sporocysts are lemon-shaped, 15.5 (14.6-15.8) × 9.5 (9.5-10.2) μm, with a shape index of 1.6. Stieda and substieda bodies are present, the Stieda body being knob-like and the substieda body being subspherical-shaped. A sporocyst residuum is present and composed of numerous granules of different size scattered among the sporozoites, a spheroid or subspheroid refractile body is present in the sporozoite. Morphologically, the oocysts from this isolate are different from those of all known valid Isospora spp. Molecular analysis was conducted at 3 loci; the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) gene. At the 18S locus, this new isolate exhibited 99.2% similarity to Isospora gryphoni and three other Isospora spp. Further analysis of a subgroup of 300 bp long 18S sequences (8), including Isospora anthochaerae was conducted. This new isolate grouped in a clade with I. anthochaerae and exhibited 99.3% similarity. At the 28S locus, this new isolate grouped with I. anthochaerae with which it shared 99.1% similarity. At the COI locus, this new isolate exhibited 96.8% similarity to Isospora sp. JCI-2015 from a spectacled warbler (Sylvia conspicillata) in Spain. Further analysis from a subgroup of shorter COI sequences (n = 13) was performed and this new isolate exhibited 99.1% similarity to I. anthochaerae. Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora manorinae n. sp

  8. A complex small RNA repertoire is generated by a plant/fungal-like machinery and effected by a metazoan-like Argonaute in the single-cell human parasite Toxoplasma gondii.

    Science.gov (United States)

    Braun, Laurence; Cannella, Dominique; Ortet, Philippe; Barakat, Mohamed; Sautel, Céline F; Kieffer, Sylvie; Garin, Jérôme; Bastien, Olivier; Voinnet, Olivier; Hakimi, Mohamed-Ali

    2010-05-27

    In RNA silencing, small RNAs produced by the RNase-III Dicer guide Argonaute-like proteins as part of RNA-induced silencing complexes (RISC) to regulate gene expression transcriptionally or post-transcriptionally. Here, we have characterized the RNA silencing machinery and exhaustive small RNAome of Toxoplasma gondii, member of the Apicomplexa, a phylum of animal- and human-infecting parasites that cause extensive health and economic damages to human populations worldwide. Remarkably, the small RNA-generating machinery of Toxoplasma is phylogenetically and functionally related to that of plants and fungi, and accounts for an exceptionally diverse array of small RNAs. This array includes conspicuous populations of repeat-associated small interfering RNA (siRNA), which, as in plants, likely generate and maintain heterochromatin at DNA repeats and satellites. Toxoplasma small RNAs also include many microRNAs with clear metazoan-like features whose accumulation is sometimes extremely high and dynamic, an unexpected finding given that Toxoplasma is a unicellular protist. Both plant-like heterochromatic small RNAs and metazoan-like microRNAs bind to a single Argonaute protein, Tg-AGO. Toxoplasma miRNAs co-sediment with polyribosomes, and thus, are likely to act as translational regulators, consistent with the lack of catalytic residues in Tg-AGO. Mass spectrometric analyses of the Tg-AGO protein complex revealed a common set of virtually all known RISC components so far characterized in human and Drosophila, as well as novel proteins involved in RNA metabolism. In agreement with its loading with heterochromatic small RNAs, Tg-AGO also associates substoichiometrically with components of known chromatin-repressing complexes. Thus, a puzzling patchwork of silencing processor and effector proteins from plant, fungal and metazoan origin accounts for the production and action of an unsuspected variety of small RNAs in the single-cell parasite Toxoplasma and possibly in other

  9. Utilization of inherent miRNAs in functional analyses of Toxoplasma gondii genes.

    Science.gov (United States)

    Crater, Anna K; Manni, Emad; Ananvoranich, Sirinart

    2015-01-01

    MicroRNAs (miRNAs) are crucial genetic effectors partaking in numerous mechanisms of gene regulation in eukaryotic organisms. Recent discoveries of miRNA in Toxoplasma gondii, an intracellular obligate parasite of the phylum Apicomplexa, suggested possible roles of T. gondii miRNAs (Tg-miRNAs) in the post-transcriptional gene regulation and in the cell biology of the parasite. To gain a better understanding of the involvement of Tg-miRNAs in regulating the parasite gene expression, a dual luciferase reporter system was used in the examination and evaluation of the effects of endogenous Tg-miRNAs, their mimics and inhibitors. A Renilla luciferase (Rnluc) transcript was engineered to carry independent binding sites of two abundant species, namely Tg-miR-60a and Tg-miR-4a, so that the expression of Rnluc was silenced in a sequence specific manner by Tg-miR-60a and Tg-miR-4a. Notably, Tg-miR-60a, but not Tg-miR-4a, caused the levels of Rnluc transcripts to decrease. These findings strongly suggested that T. gondii employs the Tg-miRNA species-specific mode of silencing actions: transcript degradation by Tg-miR-60a, and translational suppression by Tg-miR-4a. Herein we developed a genetic system that exploits and directs the most abundant Tg-miR-60a for loss-of-function analyses in T. gondii. As a proof of principle, we showed that when the binding sites for Tg-miR-60a were introduced into the parasite transcripts via homologous recombination at the locus of (i) DEAD-box RNA helicase (TgHoDI), or (ii) lactate dehydrogenase isoform 1 (TgLDH1), the expression levels of the selected genes can be altered. It was thus proven that inherit Tg-miR-60a could be directed and used to assist in the loss-of-function analyses.

  10. Bovine besnoitiosis in Switzerland: imported cases and local transmission.

    Science.gov (United States)

    Basso, Walter; Lesser, Maren; Grimm, Felix; Hilbe, Monika; Sydler, Titus; Trösch, Luzia; Ochs, Hansueli; Braun, Ueli; Deplazes, Peter

    2013-12-01

    Bovine besnoitiosis is an economically important disease of cattle, caused by Besnoitia besnoiti (Protozoa, Apicomplexa). A considerable spreading of this parasitic infection has been observed in Europe in the last ten years, mainly related to animal trade. In order to investigate the possibility of B. besnoiti being unnoticed introduced and getting established in Switzerland through the import of breeding cattle from France, a total of 767 animals (650 cattle imported from France and 117 cattle that had contact with B. besnoiti positive cattle in Swiss farms) were screened for antibodies against B. besnoiti by both a commercial ELISA and by the indirect fluorescent antibody test (IFAT). A total of 101 (13.17%) samples showed a positive reaction in ELISA (cut-off: percent of positivity [PP] ≥ 15) and 16 (2.09%) samples had IFAT titers ≥ 1:100. Eight of those samples reacted positive in Western blot (WB), corresponding to five imported Limousin cattle (two cows and one bull from France and two cows from Germany) and to three cattle born in Switzerland (one Limousin heifer born from one of the positive German cows, and two adult Braunvieh cows, that had been in contact with one of the French cows at a Swiss farm). Seven of those animals were subclinically infected and one animal showed only very mild signs. They were subsequently slaughtered, and the serological diagnosis could be confirmed by real-time PCR and/or histopathology in seven animals. The most frequent parasite localizations were the tendons and surrounding connective tissue of the distal limbs and the skin of the head region. Furthermore, B. besnoiti could be successfully isolated in vitro from one French, one German and one Swiss cattle (isolates Bb-IPZ-1-CH, Bb-IPZ-2-CH and Bb-IPZ-3-CH). In the current situation in Switzerland, prophylactic and control measures should include a serological examination of cattle to be imported from endemic areas and the culling of all confirmed positive animals from

  11. Genome BLAST distance phylogenies inferred from whole plastid and whole mitochondrion genome sequences

    Directory of Open Access Journals (Sweden)

    Holland Barbara R

    2006-07-01

    judged by their δ values, distance methods are able to recover all major plant lineages, and are more in accordance with Apicomplexa organelles being derived from "green" plastids than from plastids of the "red" type. GBDP-like methods can be used to reliably infer phylogenies from different kinds of genomic data. A framework is established to further develop and improve such methods. δ values are a topology-independent tool of general use for the development and assessment of distance methods for phylogenetic inference.

  12. 不同引物扩增对东海陆架沉积物真核微型生物多样性的影响%EFFECTS OF AMPLIFICATION WITH DIFFERENT PRIMERS ON MICROEUKARYOTIC DIVERSITY IN THE SURFACE LAYER SEDIMENTS OF THE EAST CHINA SEA

    Institute of Scientific and Technical Information of China (English)

    俞凯成; 王健鑫; 陶诗; 刘明华; 蒋然; 刘雪珠; 黄备

    2014-01-01

    采用三对通用引物(ITS1/ITS4,EF3/EF4,NS1/NS4)检测其对东海陆架DH-13站点表层沉积物真核微型生物的扩增特异性和多样性差异.对323个有效克隆子进行OTU分型和多样性分析,结果表明,NS1/NS4引物扩增所获得的文库多样性最高,EF3/EF4其次,ITS 1/ITS4最后.通过NCBI比对和分类学研究,发现优势种群主要为原生生物界,包括丝足虫门(Cercozoa,占所有OTU的36.4%)、横裂甲藻纲(Dinophyceae,占14.2%)、不等鞭毛门(Stramenopiles,占7.4%)和纤毛虫门(Ciliophora,占6.3%);另含部分真菌界如子囊菌门(Ascomycota,占7.4%)和壶菌门(Chytridiomycota,占6.3%).原生生物方面,NS1/NS4引物表现的多样性最高,适合于扩增丝足虫门、横裂甲藻纲和不等鞭毛门,并扩增到独有的眼虫门(Euglenozoa)、隐藻门(Cryptophyta)和顶复门(Apicomplexa);ITS1/ITS4适合于扩增甲藻和纤毛虫门;EF3/EF4则适合于丝足虫门.真菌方面,ITS1/ITS4适合于扩增子囊菌门;EF3/EF4适合于子囊菌门和壶菌门,而NS1/NS4适合于壶菌门.系统发育分析表明,三对引物的原生生物系统树中的相似序列多来自海洋环境样品,真菌序列则分别来自陆地土壤真菌和海洋真菌,说明三对引物更适合于海洋沉积环境微型原生生物的分子生态分析.%Three pairs of universal primer (ITS1/ITS4,EF3/EF4 and NS1/NS4) were applied to determine the amplification specificity and diversity difference in microeukaryotes isolated from surface sediment at station DH-13,on the East China Sea shelf.After the OTU classification and diversity analysis on 323 valid clones,we demonstrate that the library generated by the amplification of primer NS1/NS4 obtains the highest diversity,followed by the EF3/EF4,and then the ITS 1/ITS4.Through comparison with NCBI and taxonomical study,we found that the dominant species mainly belong to the Protista,which includes Cercozoa (accounting for 36.4% of the total OTU),Dinophyceae (14

  13. Antiprotozoan lead discovery by aligning dry and wet screening: prediction, synthesis, and biological assay of novel quinoxalinones.

    Science.gov (United States)

    Martins Alho, Miriam A; Marrero-Ponce, Yovani; Barigye, Stephen J; Meneses-Marcel, Alfredo; Machado Tugores, Yanetsy; Montero-Torres, Alina; Gómez-Barrio, Alicia; Nogal, Juan J; García-Sánchez, Rory N; Vega, María Celeste; Rolón, Miriam; Martínez-Fernández, Antonio R; Escario, José A; Pérez-Giménez, Facundo; Garcia-Domenech, Ramón; Rivera, Norma; Mondragón, Ricardo; Mondragón, Mónica; Ibarra-Velarde, Froylán; Lopez-Arencibia, Atteneri; Martín-Navarro, Carmen; Lorenzo-Morales, Jacob; Cabrera-Serra, Maria Gabriela; Piñero, Jose; Tytgat, Jan; Chicharro, Roberto; Arán, Vicente J

    2014-03-01

    which the individual QSAR outputs are the inputs of the aforementioned fusion approach. Finally, the fusion model was used for the identification of a novel generation of lead-like antiprotozoan compounds by using ligand-based virtual screening of 'available' small molecules (with synthetic feasibility) in our 'in-house' library. A new molecular subsystem (quinoxalinones) was then theoretically selected as a promising lead series, and its derivatives subsequently synthesized, structurally characterized, and experimentally assayed by using in vitro screening that took into consideration a battery of five parasite-based assays. The chemicals 11(12) and 16 are the most active (hits) against apicomplexa (sporozoa) and mastigophora (flagellata) subphylum parasites, respectively. Both compounds depicted good activity in every protozoan in vitro panel and they did not show unspecific cytotoxicity on the host cells. The described technical framework seems to be a promising QSAR-classifier tool for the molecular discovery and development of novel classes of broad-antiprotozoan-spectrum drugs, which may meet the dual challenges posed by drug-resistant parasites and the rapid progression of protozoan illnesses.

  14. Antiprotozoan lead discovery by aligning dry and wet screening: prediction, synthesis, and biological assay of novel quinoxalinones.

    Science.gov (United States)

    Martins Alho, Miriam A; Marrero-Ponce, Yovani; Barigye, Stephen J; Meneses-Marcel, Alfredo; Machado Tugores, Yanetsy; Montero-Torres, Alina; Gómez-Barrio, Alicia; Nogal, Juan J; García-Sánchez, Rory N; Vega, María Celeste; Rolón, Miriam; Martínez-Fernández, Antonio R; Escario, José A; Pérez-Giménez, Facundo; Garcia-Domenech, Ramón; Rivera, Norma; Mondragón, Ricardo; Mondragón, Mónica; Ibarra-Velarde, Froylán; Lopez-Arencibia, Atteneri; Martín-Navarro, Carmen; Lorenzo-Morales, Jacob; Cabrera-Serra, Maria Gabriela; Piñero, Jose; Tytgat, Jan; Chicharro, Roberto; Arán, Vicente J

    2014-03-01

    which the individual QSAR outputs are the inputs of the aforementioned fusion approach. Finally, the fusion model was used for the identification of a novel generation of lead-like antiprotozoan compounds by using ligand-based virtual screening of 'available' small molecules (with synthetic feasibility) in our 'in-house' library. A new molecular subsystem (quinoxalinones) was then theoretically selected as a promising lead series, and its derivatives subsequently synthesized, structurally characterized, and experimentally assayed by using in vitro screening that took into consideration a battery of five parasite-based assays. The chemicals 11(12) and 16 are the most active (hits) against apicomplexa (sporozoa) and mastigophora (flagellata) subphylum parasites, respectively. Both compounds depicted good activity in every protozoan in vitro panel and they did not show unspecific cytotoxicity on the host cells. The described technical framework seems to be a promising QSAR-classifier tool for the molecular discovery and development of novel classes of broad-antiprotozoan-spectrum drugs, which may meet the dual challenges posed by drug-resistant parasites and the rapid progression of protozoan illnesses. PMID:24513185

  15. Intestinal Coccidia

    Directory of Open Access Journals (Sweden)

    MJ Ggaravi

    2007-06-01

    Full Text Available Intestinal Coccidia are a subclass of Apicomplexa phylum. Eucoccidida are facultative heteroxenous, but some of them are monoxenous. They have sexual and asexual life cycle. Some coccidia are human pathogens, for example: Cryptosporidium: Cryptosporidiums has many species that are mammalian intestinal parasites.C. Parvum specie is a human pathogenic protozoa. Cryptosporidum has circle or ellipse shapes and nearly 4-6 mm. It is transmitted in warm seasons. Oocyst is obtained insexual life cycle that has 20% thin layer and 80% thick layer. Oocyst with thick layer is able to live a long time in nature. They are the third or forth of gastroentritis disease that have digestive disorder like anorexia, nausea, persistent diarrhoea, malabsorption and leanness. The disease forms choronic and acute stages and it is able to kill the immunodeficiency cases. Sometimes it has HIV symptoms similar to pneumonia and respiratory track infection. Laboratory diagnosis is based on Oocyst finding in stool exam and that shitter floatation and Cr (KOH2 are the best methods. Modified zyh-lnelson and fleocroum are the best staining methods too. This parasite is transmitted by zoonotic and Antroponotic origin. Molecular studies have shown two Genotypes (I&II. Genotype I is aquatic and II is zoonotic. The prevalence rate is 3% in infants and 10% in calves. Cyclospora: This parasite is novel and is bigger than cryptosporidium.It isn't known a clear life cycle but is transmitted by water, vegetables and fruits as raspberries. and mulberries. Human is a specific host. When a parasite is in the intestine it causes inflammatory reaction in Entrocyte.The patient shows watery diarrhoea with nausea, vomitting, pain, Stomach cramp, anorexia, malabsorption and cachexia. The disease period is 3 monthes in immunodeficiency cases but it is selflimited in normal cases. Autofluorescence characteristic is differential diagnosis, prevalence rate of disease is unknown. Isospora: This

  16. Resolving the Divergence Times and Major Evolutionary Relationships of Protoctists%原生生物物种分歧时间和主要演化关系的定量计算

    Institute of Scientific and Technical Information of China (English)

    李可群

    2016-01-01

    The divergence times and evolutionary relationships of some major protoctist clades were resolved by equation for molecular absolute evolutionary rates and several protein molecules:EF-1α,EF-2,NADH1 and CytB.The results showed that protoctists evolved from the route as:algae→fungi→protozoan.Their respective evolutionary routes are:(1) After the seperation of red algae at 1.331 Ga ago,the green algae separated from it around 1.1744 Ga ago, Mosses seperated at 0.4527 Ga ago,ferns seperated at 0.437 Ga ago.The divergence times of club-mosses,liverworts, Chlamydomonadales and Chlorellales are 0.4185,0.4457,0.5202 and 0.5239 Ga ago,respectively;(2) both Slime molds and oomycetes belonge to Fungi evolutionary branch,which separated about 1.0456 and 0.9032 Ga ago;(3) In protozoan branch,Apicomplexa and Choanoflagellates separated about 1.045 and 0.8122 Ga ago,respectively.Our results agreed well with the references work based on fossil records,and provided a new way to precisely resolve the evolutionary relationships of all protoctists.%使用本文作者提出的分子绝对进化速率的计算公式和EF-1α,EF-2,NADH1和CytB等蛋白质分子,对原生生物的一些主要类群:藻类、真菌和原生动物的物种分歧时间和演化关系进行了定量计算.结果显示,原核生物沿着藻类→真菌→原生动物的方向演化.它们的演化关系为:(1)红藻自13.31亿年前分化出后,于11.74亿年前分化出绿藻,绿藻于4.527亿年前分化出藓类,4.37亿年前分化出蕨类;其他物种如石松类、肝苔类、团藻和小球藻分别于4.185亿年前、4.457亿年前、5.202亿年前和5.239亿年前分化出;(2)黏菌和卵菌均属于真菌进化分枝,分别于10.456亿年前和9.032亿年前分化出;(3)原生动物进化分枝中于10.45亿年前分化出孢子虫等,8.122亿年前领鞭毛虫与多细胞动物分化.这些结果均与基于化石记录的文献报道相符.

  17. 艾美耳球虫子孢子从宿主细胞中逸出机制的初步研究%PRELIMINARY STUDY ON THE MECHANISMS OF RAPID EGRESS OF EIMERIA TENELLA SPOROZOITES FROM HOST CELLS

    Institute of Scientific and Technical Information of China (English)

    闫鑫磊; 计永胜; 田秀玲; 索静霞; 刘贤勇; 索勋

    2014-01-01

    Apicomplexan parasites infect nearly all vertebrate hosts even including humans and cause some severe diseases such as malaria, toxoplasmosis, cryptosporidiosis which are responsible for substantial economic losses. Like most intracellular pathogens, egress from host cells is a vital step of the apicomplexan parasites, which attracted attentions of many research groups.Unfortunately, as an important genus of Phylum Apicomplexa, little information of egress is known on Eimeria species which leads large amount of losses to poultry industry annually.In this report we used ethanol to induce egress of E.tenella M2e transgenic strain (EtM2e) sporozoites which express yellow fluorescent protein (YFP).Results showed that ethanol could induce egress of EtM2e sporozoites from infected Madin Derby Bovine Kidney ( MDBK) cells, and this process was depended on the mobility of the parasites.We also found that ethanol could also stimulate microneme protein discharge.Furthermore, both the course of egress and the secretion of microneme were controlled by the flux of intracellular Ca2+of the parasite.Taken together, our results preliminarily explained the mechanism of egress of eimerian parasites, which provided clues to the further study.%艾美耳球虫是一类重要的肠道病原,其裂殖生殖阶段的虫体逸出过程是造成畜禽肠道破坏的主要原因之一,但此逸出过程的机制仍鲜有报道。本研究以乙醇作为诱导剂研究柔嫩艾美耳球虫M2 e株子孢子从宿主细胞中逸出的机制。结果显示,乙醇可诱导子孢子从MDBK细胞中逸出,此逸出过程依赖于虫体的运动能力;同时,乙醇可激发子孢子逸出相关的微线体蛋白2( Mic2)的分泌释放。进一步实验证实,螯合虫体内部钙离子明显阻断了子孢子逸出及Mic2蛋白的释放。本研究初步证实了与柔嫩艾美耳球虫逸出相关的蛋白和离子,为深入解析球虫致病的分子机制、研发新型抗球

  18. 我国鸟类原虫种类与感染状况研究进展%RESEARCH PROGRESS ON PROTOZOAN SPECIES AND INFECTION STATUS IN BIRDS IN CHINA

    Institute of Scientific and Technical Information of China (English)

    李榴佳; 黄兵; 舒凡帆; 吴有陵

    2013-01-01

    的防控和保护鸟类具有十分重要的指导意义。%Protozoa are a group of common parasites in birds and puts a threaten to public health in humans. In order to keep abreast of the recent protozoan species and infection status in birds in China, we have reviewed a lot of literatures about protozoan studies. In summary, 70 species of protozoa have been recorded in birds of China. These species are classified into 3 phyla (Apicomplexa, Sarcomastigophora, Sarcomastigophora), 4 classes (Sporozoa, Zoomastigophora, Lobosasida, Blastocystidea), 5 orders (Eucoccidiorida,Haemospororida, Trichomonadorida, Amoebida, Blastocystida), 9 families (Eimeiridae, Cryptosporidiidae, Sarcocystidae, Plasmodiidae, Leucocystozoidae, Monocercomonadidae, Trichomonadidae, Entamoebidae, Blastocystidae), and 12 genera. There are 23 species in Plasmodium, 20 species in Eimeria, 15 species in Leucocytozoon, 3 species in Cryptosporidium, 2 species in Isospora, and 1 species in each of Toxoplasm, Haemoproteus, Histomonas, Trichomonas, Entamoeba, Endolimax and Blastocystis. All in all, common protozoa in birds are coccidia, Plasmodium and Cryptosporidium. Coccidia, Plasmodium, Haemoproteus and Trichomonad often cause infection in birds and Cryptosporidium, Toxoplasma, Amoeba and Blastocystis can infect humans. Understanding on protozoan species and infections in birds may provide important guidance for the control of protozoosis in China.