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Eimeria tiliquae n. sp. (Apicomplexa: Eimeriidae) from the shingleback skink (Tiliqua rugosa rugosa)
Supplementary resources (3)
Nucleotide Sequence
September 2012
Nucleotide Sequence
September 2012
Nucleotide Sequence
September 2012
... At the COI gene locus, this new isolate was most closely related to Isospora sp. isolate COI-178 and Eimeria tiliquae [25,26], presented 96.5% and 96.2% genetic similarity, respectively. Based on the morphological and molecular data, this isolate is a new species of coccidian parasite, which is named Eimeria briceae n. sp. ...
... Phylogenetic analysis showed that E. briceae n. sp. shared a clade with Eimeria tiliquae [25,26] (JX839284), which was identified from a shingleback skink (Tiliqua rugosa rugosa (Gray, 1825)) in Western Australia [25] (Fig. 5). In addition, an Isospora sp. ...
... Phylogenetic analysis showed that E. briceae n. sp. shared a clade with Eimeria tiliquae [25,26] (JX839284), which was identified from a shingleback skink (Tiliqua rugosa rugosa (Gray, 1825)) in Western Australia [25] (Fig. 5). In addition, an Isospora sp. ...
A new Eimeria Schneider, 1875 species is described from an Australian pelican Pelecanus conspicillatus Temminck, 1824 in Western Australia. Sporulated oocysts (n = 23) subspheroidal, 33-35 × 31-33 (34.1 × 32.0) μm; length/width (L/W) ratio 1.0-1.1 (1.07). Wall bi-layered, 1.2-1.5 (1.4) μm thick, outer layer smooth, c.2/3 of total thickness. Micropyle absent, but 2 or 3 polar granules surrounded by a thin membrane, apparently residual, are present. Sporocysts (n = 23) elongate ellipsoidal or capsule shaped, 19-20 × 5-6 (19.5 × 5.6) μm; L/W ratio 3.4-3.8 (3.51). Stieda body vestigial and barely discernible, 0.5 × 1.0 μm; sub-Stieda and para-Stieda bodies absent; sporocyst residuum present, composed of a few dense spherules dispersed among the sporozoites. Sporozoites with robust anterior and posterior refractile bodies and centrally located nucleus. Molecular analysis was conducted at three loci; the 18S and 28S ribosomal RNA genes and the cytochrome c oxidase subunit I (COI) gene. At the 18S locus, the new isolate shared 98.6% genetic similarity with Eimeria fulva Farr, 1953 (KP789172), which was identified from a goose in China. At the 28S locus, the new isolate shared the highest similarity of 96.2% with Eimeria hermani Farr, 1953 (MW775031) identified from a whooper-swan (Cygnus cygnus (Linnaeus, 1758)) in China. At the COI gene locus, this new isolate was most closely related to Isospora sp. isolate COI-178 and Eimeria tiliquae [25,26], presented 96.5% and 96.2% genetic similarity, respectively. Based on the morphological and molecular data, this isolate is a new species of coccidian parasite, which is named Eimeria briceae n. sp.
... In an experimental infection of the lizards Heremites vittatus (Olivier, 1804) (reported as Mabuya vitatta) and Stellagama stellio (Linnaeus, 1758) (reported as Agama stellio) with H. mariae, it was found that the developmental schedule of the parasite was retarded (Paperna & Smallridge, 2001), which may suggest a degree of host specificity. Another potentially host-specific protozoan parasite of sleepy lizards is Eimeria tiliquae Yang, Brice, Ryan, and Bennett, 2013 (Family: Eimeriidae), which was found in the faeces of T. rugosa from Western Australia (Yang et al., 2013). Eimeria infections are usually via the oralfaecal route, and although most of these protozoans are host specific, a particular host may be infected by multiple species (Rose, 1985). ...
... Eimeria infections are usually via the oralfaecal route, and although most of these protozoans are host specific, a particular host may be infected by multiple species (Rose, 1985). In a survey of T. rugosa specimens that were admitted to a rehabilitation centre in Western Australia, it was found that about 21% were infected by Eimeria sp., and although some of the infected lizards had symptoms of upper respiratory tract infections, none had signs of gastrointestinal infections (Yang et al., 2013). ...
... (Family: Trichomonadidae) and Balantidium spp. (Family: Balantiididae) trophozoites were recorded from sleepy lizards from Western Australia (Yang et al., 2013). Johnston (1932) ...
Parasitism is a very common life strategy and although it results in harm to the host, it plays a vital ecological role in host population and community dynamics. The sleepy lizard, Tiliqua rugosa, is one of the best studied lizard species in Australia, to a large extent due to studies involving ticks that infest these lizards. In spite of this, little is known about most of the parasites that are known to infect sleepy lizards. The purpose of this review is to provide a synopsis of the species that have been reported as parasites of T. rugosa as a foundation for future studies.
... Eimeria tiliquae Yang, Brice, Ryan, and Bennett, 2013 Type host: Tiliqua rugosa rugosa Gray, 1825, shingleback skink. Remarks: This species was originally discovered and named in Australia based on sporulated oocyst morphometric data and 2 partial 18S rDNA sequences (1,300 and 1,302 bp) and mitochondrial cytochrome c oxidase (CO1) gene sequences (720 bp). ...
... Remarks: This species was originally discovered and named in Australia based on sporulated oocyst morphometric data and 2 partial 18S rDNA sequences (1,300 and 1,302 bp) and mitochondrial cytochrome c oxidase (CO1) gene sequences (720 bp). Although their phylogenetic analysis of the 18S rDNA sequence showed 96.4-96.5 similarity to A. (E.) tropidurua, they did not include sequences of any Acroeimeria in their phylogenetic analyses and, consequently, did not attempt to reassign E. tiliquae to the Acroeimeria (Yang et al., 2013). Their phylogenetic analysis of E. tiliquae placed it ''in a clade by itself but grouping closest (92% similarity) with a novel isolate from a King's skink (Egernia kingii) from Western Australia'' (Yang et al., 2013, p. 144). ...
Between June 2016 and June 2019, we surveyed 62 Mediterranean geckos, Hemidactylus turcicus, from Abu Rawash, Giza, Egypt, for the presence of endoparasites. In June 2016, we found 3 individuals to be infected with Eimeria lineri. We studied the morphology and inner structures of its sporulated oocysts, and the locations of its intestinal endogenous stages. We also extracted genomic DNA from these sporulated oocysts and successfully sequenced a 632-bp fragment of the 18S rRNA gene. Phylogenetic analyses using this partial sequence allowed us to support previous studies that assigned E. lineri to the genus Acroeimeria. Our consensus sequence was used to query similar 18S rDNA sequences from GenBank, and 14 sequences were selected. The phylogenetic analysis inferred by maximum likelihood and Bayesian inference methods gave similar results, as both separated the sequences into 2 clades: (1) a monophyletic group of Goussia species (from fish); and (2) a strongly supported clade that separated 4 Choleoeimeria species from a polyphyletic group of species that clustered A. lineri with 3 other Acroeimeria species and 3 Eimeria species from lizards, including Eimeria tiliquae from Tiliqua rugosa (Gray, 1825), Eimeria tokayae from Gecko gecko (L., 1758), and Eimeria eutropidis from Eutropis macularia (Blyth, 1853). Our study supports the placement of E. lineri into the Acroeimeria and contributes additional life history information toward understanding the evolutionary origin of the Eimeria-like species that have sporocysts without Stieda bodies in their oocysts and that infect saurian reptiles. We also support the concept that several traits (morphological, endogenous, and gene sequences) are both necessary and important for authors to include when making generic reassignments within the eimeriid coccidia.
... Amplification of the Eimeria 18S rRNA region was performed using PCR according to the protocols described by Yang et al. (2016). To identify singular species, cloning of the PCR product was performed as described previously by Yang et al. (2013a) while sequencing and DNA purification were conducted according to previously described protocols (Yang et al., 2013b). ...
A novel Eimeria Schneider, 1875 species is described from an Australian pied oystercatcher Haematopus longirostris Vieillot, in Western Australia. The pied oystercatcher was admitted to the Kanyana Wildlife Rehabilitation Centre (KWRC), Perth, Western Australia in a poor body condition, abrasion to its right hock and signs of partial delamination to its lower beak. Investigation into potential medical causes resulted in a faecal sample being collected and screened for gastrointestinal parasites. Unsporulated coccidian oocysts were initially observed in the faeces and identified as Eimeria upon sporulation. The sporulated oocysts (n = 20) are ellipsoidal, 20–21 × 12–13 μm in shape and have thick bi-layered walls which are c.2/3 of the total thickness. Micropyle is present, robust and protruding, and occasionally has a rounded polar body attached to the micropyle. Within the oocyst, a residuum, in addition, two to five polar granules are present. There are four ellipsoidal sporocysts 9–11 × 5–6 μm with flattened to half-moon shaped Stieda bodies. Sub-Stieda body and para-Stieda body are absent. The sporocysts contain sporocyst residuums composed of a few spherules scattered among the sporozoites. Within the sporozoites, anterior and posterior refractile bodies are present, but the nucleus is indiscernible. To further characterise the novel Eimeria species from H. longirostris, molecular analysis was conducted at the 18S ribosomal RNA locus, using PCR amplification and cloning. Two cloned sequences from the novel Eimeria were compared with those from other Eimeria spp. with the highest genetic similarity of 97.6% and 97.2% from Clone 1 and 2, respectively with Eimeria reichenowi (AB544308) from a hooded crane (Grus monacha Temminck) in Japan. Both sequences grouped in a clade with the Eimeria spp. isolated from wetland birds, which include Eimeria paludosa (KJ767187) from a dusky moorhen (Gallinula tenebrosa Gould) in Western Australia, Eimeria reichenowi (AB544308) and Eimeria gruis (AB544336) both from hooded cranes. Based on the morphological and molecular data, this Eimeria sp. is a new species of coccidian parasite and is named Eimeria haematopusin. sp. after its host H. longirostris.
... These approaches have been very useful and have highlighted many issues with the taxonomy of Eimeria including its paraphyletic nature (Morrison et al. 2004). However, one of the difficulties with genetic characterisation of Eimeria species using Sanger sequencing of PCR amplicons is the inability to reliably audit multiple species present in individual hosts due to mixed chromatograms, which has resulted in some studies resorting to the use of micromanipulation to isolate individual oocysts for molecular analyses Al-Habsi et al. 2017) or molecular cloning of amplicons, which is time-consuming and expensive, to obtain individual sequences from mixed Eimeria infections (Yang et al. 2013). ...
Eimeria is an important coccidian enteric parasite that infects a wide range of hosts and can cause substantial economic losses in the poultry and livestock industries. It is common for multiple Eimeria species to infect individual hosts, and this can make species identification difficult due to morphological similarities between species and mixed chromatograms when using Sanger sequencing. Relatively few studies have applied next-generation amplicon sequencing (NGS) to determining the genetic diversity of Eimeria species in different hosts. The present study screened 408 faecal samples from a range of hosts including livestock and wildlife using a previously developed quantitative polymerase chain reaction (qPCR) at the 18S locus and conducted amplicon NGS on the positives using a ~ 455-bp fragment of the 18S locus. A total of 41 positives (10.1%) were identified by qPCR from various hosts and NGS was successful for 38 of these positives. Fifteen Eimeria species and three genotypes were detected by NGS: E. ferrisi, E. kanyana, E. potoroi, E. quokka, E. setonicis, E. trichosuri, E. reichenowi, E. angustus, E. ahsata, E. auburnensis, E. bovis, E. brasiliensis, E. christenseni, E. crandallis, E. ovinoidalis, Eimeria sp. (JF419345), Eimeria sp. (JF419349) and Eimeria sp. (JF419351). Mixed infections were detected in 55.3% (21/38) of positive samples. The most striking finding was the identification of the same species in different hosts. This could be due to contamination and/or mechanical transmission or may provide support for previous studies suggesting that Eimeria species can infect not just closely related hosts but different genera and further research is required. This is also the first study to audit Eimeria populations in livestock (sheep and cattle) by NGS and could be applied in the future to determine the extent of pathogenic species and outcomes of Eimeria control strategies.
... Abbreviations: PG, polar granule; SP, sporocyst; SR, sporocyst residuum. Scale-bars: 10 lm 1993, 2014aPaperna, 2007;Yang et al., 2013). The low scientific effort in this part of the world, however, suggests that much of the eimerian diversity remains to be discovered as very few hosts have been surveyed. ...
A new species of Eimeria Schneider, 1875 from rainbow skinks, Carlia ailanpalai Zug and Carlia
eothen Zug is described from specimens collected in Papua New Guinea (PNG). Oöcysts of Eimeria
zugi n. sp. from one of one (100%) C. eothen are ellipsoidal to cylindroidal, with a smooth, colourless, bi-layered wall, measure 25.1 × 15.5 μm and have a length/width ratio of 1.6. The micropyle and the oöcyst residuum are absent, but a polar granule is present. The sporocysts are ovoidal to ellipsoidal and 10.3 × 7.1 μm in size and do not contain Stieda, sub-Stieda or para-Stieda bodies; and the sporocyst residuum is composed of a compact mass of large globules. The sporozoites are elongate, 12.8 × 2.9 μm in size, and contain anterior and posterior refractile bodies with a nucleus between them. This is the ninth species of coccidium described from skinks from PNG, and the new species described herein is apparently endemic to the skink genus Carlia (Gray).
A respiratory disease syndrome has been observed in large numbers of wild shingleback lizards (Tiliqua rugosa) admitted to wildlife care facilities in the Perth metropolitan region of Western Australia. Mortality rates are reportedly high without supportive treatment and care. Here we used next generation sequencing techniques to screen affected and unaffected individuals admitted to Kanyana Wildlife Rehabilitation Centre in Perth between April and December 2015, with the resultant discovery of a novel nidovirus significantly associated with cases of respiratory disease according to a case definition based on clinical signs. Interestingly this virus was also found in 12% of apparently healthy individuals, which may reflect testing during the incubation period or a carrier status, or it may be that this agent is not causative in the disease process. This is the first report of a nidovirus in lizards globally. In addition to detection of this virus, characterisation of a 23,832 nt segment of the viral genome revealed the presence of characteristic nidoviral genomic elements providing phylogenetic support for the inclusion of this virus in a novel genus alongside Ball Python nidovirus, within the Torovirinae sub-family of the Coronaviridae. This study highlights the importance of next generation sequencing technologies to detect and describe emerging infectious diseases in wildlife species, as well as the importance of rehabilitation centres to enhance early detection mechanisms through passive and targeted health surveillance. Further development of diagnostic tools from these findings will aid in detection and control of this agent across Australia, and potentially in wild lizard populations globally.
The occurrence of apicomplexan parasites in Podarcis sp. wall lizards from the Iberian Peninsula and Balearic islands was studied by amplification and sequencing of the 18S rRNA gene. Species from 3 genera, Hepatozoon , Sarcocystis , and Eimeria , were found. The phylogenetic analysis of the 18S rRNA gene provides unexpected insights into the evolutionary history of these parasites. All Hepatozoon spp. specimens were recovered as part of a clade already identified in lizards from North Africa. The Sarcocystis species, detected in Podarcis lilfordi from Cabrera Island in the Balearic Islands, appears related to Sarcocystis gallotiae , known only from endemic Gallotia sp. lizards from the Canary Islands. Based on the lack of snake predators on this island, this parasite presumably presents an atypical transmission cycle that uses the same host species as both intermediate and final host through cannibalism, like S. gallotiae . Eimeria sp. is reported for the first time from Podarcis spp. lizards. This study shows the power of detecting multiple different apicomplexan parasites through screening of tail tissue samples and blood drops that are often collected in reptiles for other purposes.
Identification of the protozoan parasite, Eimeria has traditionally relied on oocyst morphology, host range and life-cycle attributes. However, it is increasingly recognized that Eimeria species can vary in size and shape across their host range, an attribute known as 'polymorphism' that presents a unique challenge for identification. Advances in molecular tools hold promise for characterising Eimeria that may otherwise be misclassified based on morphology. Our study used morphologic and molecular traits of the oocyst life stage to identify a polymorphic parasite, Eimeria macropodis in a captive Tammar wallaby (Macropus eugenii) population in Australia. Molecular characterization highlighted the need to use multiple genetic markers (18S SSU and cytochrome c oxidase subunit I) to accurately identify E. macropodis owing to heterozygous alleles at the 18S SSU locus. This study provided an opportunity to assess the utility and shortcomings of morphologic and molecular techniques for 'pinning down' a polymorphic species. Moreover, our study was able to place E. macropodis in an evolutionary context and enhance resolution of the under-studied marsupial clade.
Within its life cycle Eimeria bovis undergoes a long lasting intracellular development into large macromeronts in endothelial cells. Since little is known about the molecular basis of E. bovis-triggered host cell regulation we applied a microarray-based approach to define transcript variation in bovine endothelial cells early after sporozoite invasion (4 h post inoculation (p.i.)), during trophozoite establishment (4 days p.i.), during early parasite proliferation (8 days p.i.) and towards macromeront maturation (14 days p.i.). E. bovis infection led to significant changes in the abundance of many host cell gene transcripts. As infection progressed, the number of regulated genes increased such that 12, 45, 175 and 1184 sequences were modulated at 4 h, 4, 8 and 14 days p.i., respectively. These genes significantly interfered with several host cell functions, networks and canonical pathways, especially those involved in cellular development, cell cycle, cell death, immune response and metabolism. The correlation between stage of infection and the number of regulated genes involved in different aspects of metabolism suggest parasite-derived exploitation of host cell nutrients. The modulation of genes involved in cell cycle arrest and host cell apoptosis corresponds to morphological in vitro findings and underline the importance of these aspects for parasite survival. Nevertheless, the increasing numbers of modulated transcripts associated with immune responses also demonstrate the defensive capacity of the endothelial host cell. Overall, this work reveals a panel of novel candidate genes involved in E. bovis-triggered host cell modulation, providing a valuable tool for future work on this topic.
The Barcode of Life Data System (bold) is an informatics workbench aiding the acquisition, storage, analysis and publication of DNA barcode records. By assembling molecular, morphological and distributional data, it bridges a traditional bioinformatics chasm. bold is freely available to any researcher with interests in DNA barcoding. By providing specialized services, it aids the assembly of records that meet the standards needed to gain BARCODE designation in the global sequence databases. Because of its web-based delivery and flexible data security model, it is also well positioned to support projects that involve broad research alliances. This paper provides a brief introduction to the key elements of bold, discusses their functional capabilities, and concludes by examining computational resources and future prospects.
From 1990 through 1994, fecal samples were collected and examined for coccidian parasites from 26 giant land tortoises Geochelone nigra, from 715 lava lizards Tropidurus spp., from 139 land iguanas Conolophus subcristatus, and from 128 marine iguanas Amblyrhynchus cristatus, all of which inhabit various islands in the Galápagos Archipelago. None of the samples from A. cristatus or from C. subcristatus was infected with coccidia. Only 1 of 26 (4%) G. nigra was infected with a single Eimeria species that we describe here as new. A total of 262 of 715 (37%) individuals representing 3 species of Tropidurus discharged oocysts of 1-3 different coccidian species; these included 2 previously described species Eimeria tropidura and Isospora insularius, and an eimerian that we describe here as new. Additionally, 104 fecal samples from Tropidurus spp. were from 51 animals recaptured in either 2 or 3 yr; 21 had no infections in any year, 15 were infected at least once, 14 were infected in 2 yr, and only 1 was infected during 3 yr. No animal was recaptured and sampled during each of the 4 yr of this study. Of the 262 infected individuals, 30 (12%) had multiple coccidial infections at the time of collection (eimerian and isosporan, or 2 eimerians). Where determination of the sexes was possible in the lava lizards, there was no difference in prevalence rates between males (39%) and females (41%). Sporulated oocysts of the new eimerian from Tropidurus are ellipsoidal, 27.1 x 15.6 (25-31 x 14-18) microns, with a polar body, but without a micropyle or oocyst residuum; they contain ellipsoidal sporocysts, 11.8 x 6.7 (10-14 x 6-8) microns, without Stieda, sub-, or parastieda bodies, but with a sporocyst residuum. Sporulated oocysts of the new eimerian from G. nigra are ellipsoidal to ovoidal, 21.6 x 18.1 (18-25 x 16-20) microns, with a large polar body, but without a micropyle or oocyst residuum; they contain ellipsoidal sporocysts 10.7 x 7.0 (8-12 x 5-8) microns, with Stieda body but no sub- or parastieda bodies. Also present is a sporocyst residuum of medium to large granules randomly distributed among the sporocysts.
Members of the suborder Eimeriina (phylum Apicomplexa: class Sporozoea: order Eucoccidiorida) have complex 1 or 2 host life cycles that involve endogenous development in the tissues of vertebrates or invertebrates and exogenous development in an oocyst, usually outside the host(s). Because tissue stages are logistically difficult or even impossible to obtain in natural (wild) host-parasite systems, the vast majority (> 98%) of species in this parasite complex are known only from the structure of their sporulated oocyst. Unfortunately, the quality of these species descriptions is uneven because no guidelines are available for workers in the field to follow. Here we propose a specific set of guidelines for the preparation of species descriptions of coccidia based predominently on the structure of the sporulated oocyst, because the oocyst is the most readily available stage in the life cycle. In addition, we emphasize that ancillary data be incorporated whenever possible with the species description; these data may include, but are not limited to, ecological parameters, prevalence, seasonal data, and the deposition of both host symbiotypes and parasite hepantotypes (= phototypes) into accredited musecums so that accurate identification of both host and parasite material can be assured in perpetuity. And finally, if oocysts are collected in pure suspension, that is, if only one coccidian species (morphotype) is present in the sample, then some oocysts should be saved in 70% ethanol and archived in an accredited museum in the event that future workers might wish to amplify and, later, sequence the parasite's DNA.
Whereas terminological recommendations require authors to use mean intensity or mean abundance to quantify parasites in a sample of hosts, awkward statistical limitations also force them to use either the median or the geometric mean of these measures when making comparisons across different samples. Here, we propose to reconsider this inconsistent practice by giving priority to biological realism in the interpretation of different statistical descriptors and choosing the statistical tools appropriate to our decisions. Prevalence, mean intensity, and indices of parasite distribution (such as median intensity) are suitable descriptors to quantify parasites in a sample of hosts. These measures have different biological interpretations and need different statistical methods to be compared between samples.
This paper reports prevalence of coccidial oocysts in fecal samples from 6 endemic and 2 introduced lizard species on Mauritius, an island nation in the Indian Ocean. Total coccidian prevalence was 54% (n = 341) for the endemic 'ornate day gecko,' Phelsuma ornata; 48% (n = 159) for the endemic 'Durrell's night gecko,' Nactus durrelli; 53% (n = 15) for the endemic 'Serpent Island night gecko,' N. serpensinsula; and 78% (n = 248) for the introduced gecko, Hemidactylus frenatus. These high prevalences may reflect lack of long-lasting immune response to coccidial infection. There were few significant differences in prevalence among age, island, sex, or body condition within species, suggesting that these coccidia are relatively nonpathogenic and have little effect on host fitness. Prevalence was higher in the dry season than the wet season. These data suggest other factors, such as low host immune response to reinfection, affect overall prevalence more significantly than the effect of humidity on oocyst survival on Mauritius. No coccidia were found in samples from the endemic 'Gunner's Quoin night gecko,' N. coindemirensis (n = 155), probably reflecting parasite extinction due to a host population bottleneck following historical introduction of rats. There was no evidence of competitive or facilitative interactions between Eimeria sp. and Isospora sp., but evidence of competition between 2 Eimeria species in the 'ornate day gecko,' Phelsuma ornata. No evidence was found of cross-species infection, suggesting that reptile coccidia have high host specificity and are, therefore, poor subjects for studies of parasite-mediated competition and the evolution of sex.
We revisit statistical tests for branches of evolutionary trees reconstructed upon molecular data. A new, fast, approximate likelihood-ratio test (aLRT) for branches is presented here as a competitive alternative to nonparametric bootstrap and Bayesian estimation of branch support. The aLRT is based on the idea of the conventional LRT, with the null hypothesis corresponding to the assumption that the inferred branch has length 0. We show that the LRT statistic is asymptotically distributed as a maximum of three random variables drawn from the chi(0)2 + chi(1)2 distribution. The new aLRT of interior branch uses this distribution for significance testing, but the test statistic is approximated in a slightly conservative but practical way as 2(l1- l2), i.e., double the difference between the maximum log-likelihood values corresponding to the best tree and the second best topological arrangement around the branch of interest. Such a test is fast because the log-likelihood value l2 is computed by optimizing only over the branch of interest and the four adjacent branches, whereas other parameters are fixed at their optimal values corresponding to the best ML tree. The performance of the new test was studied on simulated 4-, 12-, and 100-taxon data sets with sequences of different lengths. The aLRT is shown to be accurate, powerful, and robust to certain violations of model assumptions. The aLRT is implemented within the algorithm used by the recent fast maximum likelihood tree estimation program PHYML (Guindon and Gascuel, 2003).
A total of 430 avian-derived fecal specimens were randomly collected from selected Western Australian commercial aviaries,
poultry farms, hatcheries, wildlife parks, and the Perth Zoo and screened for the presence of Cryptosporidium by PCR. Of these, 27 Cryptosporidium-positive isolates were detected, characterized, and compared with 11 avian-derived isolates from the Czech Republic at the
18S rRNA and actin gene loci. Sequence and phylogenetic analysis identified four genetically distinct genotypes, avian genotypes
I to IV, from various avian hosts. In addition, the host range for Cryptosporidium galli was extended. Cryptosporidium muris and Cryptosporidium andersoni were also identified in a tawny frogmouth and a quail-crested wood partridge, respectively.
Phylogenetic analyses are central to many research areas in biology and typically involve the identification of homologous sequences, their multiple alignment, the phylogenetic reconstruction and the graphical representation of the inferred tree. The Phylogeny.fr platform transparently chains programs to automatically perform these tasks. It is primarily designed for biologists with no experience in phylogeny, but can also meet the needs of specialists; the first ones will find up-to-date tools chained in a phylogeny pipeline to analyze their data in a simple and robust way, while the specialists will be able to easily build and run sophisticated analyses. Phylogeny.fr offers three main modes. The 'One Click' mode targets non-specialists and provides a ready-to-use pipeline chaining programs with recognized accuracy and speed: MUSCLE for multiple alignment, PhyML for tree building, and TreeDyn for tree rendering. All parameters are set up to suit most studies, and users only have to provide their input sequences to obtain a ready-to-print tree. The 'Advanced' mode uses the same pipeline but allows the parameters of each program to be customized by users. The 'A la Carte' mode offers more flexibility and sophistication, as users can build their own pipeline by selecting and setting up the required steps from a large choice of tools to suit their specific needs. Prior to phylogenetic analysis, users can also collect neighbors of a query sequence by running BLAST on general or specialized databases. A guide tree then helps to select neighbor sequences to be used as input for the phylogeny pipeline. Phylogeny.fr is available at: http://www.phylogeny.fr/
new genera are proposed to accomodate new and previously described species of eimerian coccidia from reptiles which undergo endogenous development either in the bile epithelium — Choloœimoria n. gen., or in the microvillous zone of the intestinal epithelium — Acroeimeria n. gen. Endogenous development is described from 3 species, all from geckoes: C. turcicus (syn. Eimeria turcicus Upton, McAllister and Freed, 1988) from Hemidactylus turcicus in Israel; C. pachydactyli n. sp. from Pachydactylus capensis in South Africa and A. lineri (syn. Eimeria linen McAllister, Upton and Freed, 1988) from H. turcicus, Israel and H. mabouia, South Africa. Biliary epithelial cells infected by Choleœimeria become hypertrophic and are displaced to the surface of the epithelial layer. Oocysts are cyllndroid to oval, lack a stieda body and sporulate in the gall bladder. The developing endogenous stages of Acroeimeria, enclosed in the microvillous border of the host cell, expand into the intestinal lumen. Oocysts are oval-spherical, lack a stieda body and sporulation is exogenous.Twee nuwe genera word voorgestel vir nuwe sowel as reeds beskryfde spesies van reptiel Coccidia wat endogene ontwikkeling in òf die milt — Choleoeimeria n. gen., òf in die mikrovilli-sone van die intestinale epiteel — Acroeimeria n. gen. ondergaan. Endogene ontwikkeling word vir drie spesies beskryf wat almal in geitjies voorkom, d.i. C. turcicus (sin. Eimeria turcicus Upton, McAllister en Freed, 1988) van Hemidactylus turcicus in Israel; C. pachydactyli n. sp. van Pachydactylus capensis in Suid-Afrika en A. lineri (sin. Eimeria lineri McAllister, Upton en Freed, 1988) van H. turcicus, Israel en H. mabouia, Suid-Afrika. Galepiteelselle, besmet met Choleoeimeria, word hipertrofies en na die oppervlak van die epiteellaag verplaas. Oösiste is silindries tot ovaal, die stieda-liggaam is afwesig en sporulasie kom in die galblaas voor. Die ontwikkelende endogene stadium van Acroeimeria, ingesluit in die rand van die mikrovilli van die gasheerselle, verleng tot in die intestinale lumen. Die oösiste is ovaal-sferies, ’n stieda-liggaam is afwesig en sporulasie is eksogeen.
Fecal samples from 3 captive Australian blue-tongued skinks, Tiliqua multifasciata Sternfeld, 1919, from the Dallas Zoo, were examined for coccidian parasites. Two of the skinks were found to be passing oocysts of an undescribed eimerian, which we describe here as new. Sporulated oocysts of Eimeria sternfeldi n. sp. were spherical to subspherical, 16.6 x 15.9 (14.6-18.4 x 14.5-18.4) µm, with a shape index (length/width) of 1.1 (1.0-1.1). A micropyle and oocyst residuum were absent but 2 (1-4) polar granules were present. Sporocysts were ellipsoidal, 7.9 x 6.9 (6.6-9.4 x 6.4-7.4) µm, with a shape index of 1.1 (1.0-1.3). A sporocyst residuum was present, but Stieda, substieda, and parastieda bodies were absent. Sporozoites were elongate, 10.1 x 1.9 (8.8-11.2 x 1.6-2.0) µm in situ, containing an ellipsoidal posterior refractile body. This is the first report of a coccidian from a member of the genus Tiliqua.
Fecal samples of 14 Conolophus subcristatus from Isla Plaza Sur and of 24 Tropidurus delanonis from Isla Española and several satellite islets, Galápagos Islands, Ecuador, collected during June and July 1987 were examined for coccidian oocysts. None of the samples from C. subcristatus contained oocysts, but 11 of 24 (46%) samples from T. delanonis had oocysts when examined. Two Eimeria and 1 Isospora spp. were present, which we describe here as new species. Sporulated oocysts of Eimeria tropidura n. sp. are ellipsoidal, 32.5 x 23.8 (21-38 x 19-30) µm, with spheroidal to subspheroidal sporocysts, 8.2 x 7.9 (7-10 x 5-10) µm. Sporulated oocysts of Eimeria galapagoensis n. sp. are cylindroidal, 32.8 x 14.0 (27-36 x 12-17) µm, with spheroidal sporocysts 7.5 (7.5) µm. Sporulated oocysts of Isospora insularius n. sp. are spheroidal to subspheroidal, 24.5 x 22.3 (19-30 x 18-27) µ, with lemon-shaped sporocysts, 16.6 x 9.3 (9-17 x 7-13) µm. Each of the 11 positive fecal samples had oocysts of only 1 coccidian species, i.e., the different coccidian species did not share individual hosts.
Coccidian ocysts recovered from the faeces of eastern ringneck snakes, Diadophis punctatus arnyi, from Kansas, USA were found to represent a previously unreported eimerian. Ocysts of Eimeria arnyi n. sp. are subspherical, 16.915.1 (15–18.513.5–16) m, with a thin, single-layered wall and a shape-index (length/width) of 1.1 (1.1–1.3). A micropyle and ocyst residuum are absent but a large polar granule is present. The sporocysts are elongate, 13.26.9 (12–14.56.5–7) m, with Stieda and substieda bodies and a shape-index of 1.9 (1.7–2.3). Each sporozoite contains one to two anterior and a single posterior refractile bodies. Sporulation was exogenous and complete within four days at 23C.
Partial (∼ 780 bp) mitochondrial cytochrome c oxidase subunit I (COI) and near complete nuclear 18S rDNA (∼ 1,780 bp) sequences were directly compared to assess their relative usefulness as markers for species identification and phylogenetic analysis of coccidian parasites (phylum Apicomplexa). Fifteen new COI partial sequences were obtained using two pairs of new primers from rigorously characterised (sensu Reid and Long, 1979) laboratory strains of seven Eimeria spp. infecting chickens as well as three additional sequences from cloned laboratory strains of Toxoplasma gondii (ME49 and GT1) and Neospora caninum (NC1) that were used as outgroup taxa for phylogenetic analyses. Phylogenetic analyses based on COI sequences yielded robust support for the monophyly of individual Eimeria spp. infecting poultry except for the Eimeria mitis/mivati clade; however, the lack of a phenotypically characterised strain of E. mivati precludes drawing any firm conclusions regarding this observation. Unlike in the 18S rDNA-based phylogenetic reconstructions, Eimerianecatrix and Eimeria tenella formed monophyletic clades based on partial COI sequences. A species delimitation test was performed to determine the probability of making a correct identification of an unknown specimen (sequence) based on either complete 18S rDNA or partial COI sequences; in almost all cases, the partial COI sequences were more reliable as species-specific markers than complete 18S rDNA sequences. These observations demonstrate that partial COI sequences provide more synapomorphic characters at the species level than complete 18S rDNA sequences from the same taxa. We conclude that COI performs well as a marker for the identification of coccidian taxa (Eimeriorina) and will make an excellent DNA 'barcode' target for coccidia. The COI locus, in combination with an 18S rDNA sequence as an 'anchor', has sufficient phylogenetic signal to assist in the resolution of apparent paraphylies within the coccidia and likely more broadly within the Apicomplexa.
Coccidosis is one of the most commonly prevalent and economically important parasitic diseases of poultry worldwide. Chicken coccidia are protozoan parasites of the genus Eimeria. This study aimed at analysing the molecular prevalence of seven species of Eimeria infecting chickens in Tamil Nadu, India. Tissue samples (caecum, rectum and upper and mid intestines) collected from chickens exhibiting symptoms of coccidiosis were used for DNA extraction, followed by amplification of the internal transcribed spacer (ITS) region of Eimeria genome with genus-specific primers and speciation in nested polymerase chain reaction (PCR) with species-specific primers. Of 43 tissue samples examined, 25 were positive in ITS PCR and all the seven species could be identified. However, the prevalence of each species varied. In broilers, Eimeria necatrix was present in all infected chickens with Eimeria brunetti, Eimeria tenella, Eimeria maxima and Eimeria acervulina present in more than 50% of infected chickens, while Eimeria praecox and Eimeria mitis were only present in 11% to 16%. Although only 7 samples were positive among layers, the prevalence was largely similar, but with a higher prevalence of E. praecox and E. mitis and a lower prevalence of E. tenella. Multiple infections were most common, with 2-6 Eimeria species infecting the same chickens. In order to estimate the preponderance of each infecting species of Eimeria, a random cloning technique was adopted. The genus-specific ITS PCR product was cloned in a TA vector and ten clones were randomly picked and used as template for amplification of all the seven genera of Eimeria. If the specific species of Eimeria is preponderant, then the frequency of the clones showing that species-specific PCR amplification would be higher. Using this method, the most preponderant species present in the rectum, mid and upper intestines of layers was assessed to be E. acervulina, E. brunetti and E. necatrix. E. acervulina was present in 60-90%, E. necatrix in 10-30% and E. brunetti in 10-20% of the clones screened, indicating that these species could be the most preponderant Eimeria species. Intervention strategies should aim at these species. This new method of estimating preponderance of infecting Eimeria species could be used to assess the relative importance of each species at the farm or region level instead of relying only on prevalence estimates.
Eimeria spp. are the causative agents of coccidiosis, a major disease affecting many intensively-reared livestock, especially poultry. The chicken is host to 7 species of Eimeria that develop within intestinal epithelial cells and produce varying degrees of morbidity and mortality. Control of coccidiosis by the poultry industry is dominated by prophylactic chemotherapy but drug resistance is a serious problem. Strongly protective but species-specific immunity can be induced in chickens by infection with any of the Eimeria spp. At the Institute of Animal Health in Houghton, UK in the 1980s we showed that all 7 Eimeria spp. could be stably attenuated by serial passage in chickens of the earliest oocysts produced (i.e. the first parasites to complete their endogenous development) and this process resulted in the depletion of asexual development. Despite being highly attenuated, the precocious lines retained their immunizing capacity. Subsequent work led to the commercial introduction of the first live attenuated vaccine, Paracox, that has now been in use for 20 years. As much work still remains to be done before the development of recombinant vaccines becomes a reality, it is likely that reliance upon live, attenuated vaccines will increase in years to come.
Five new species of Eimeria are described, viz. E. ablephari from Ablepharus boutonii (Scincidae), E. egerniae from Egernia whitii (Scincidae), E. gehyrae from Gehyra variegata (Gekkonidae), E. lampropholidus from Lampropholis guichenoti and E. leiolopismatis from Leiolopisma challengeri. The characters of these species and the other coccidia from lizards are tabulated and a host check-list is given. Gall bladder parasitism is discussed as is the significance of complete sporogony occurring within the host's body. Some ideas concerning the possible events occurring in the evolution of the Haemosporina are presented.
I wish to thank Miss J. Arnold of the Zoology Department, University of Western Australia, for her identification of many of the lizards and Miss S. Curtis for her drawings. Finally I wish to thank Dr H. M. D. Hoyte, Department of Parasitology, University of Queensland, for his interest and helpful criticism of the manuscript.
Three new species of Isospora from Australian lizards are described, viz. Isospora amphiboluri from Amphibolurus barbatus (Agamidae), I. egerniae from Egernia whitii (Scincidae), and I. ablephari from Ablepharus boutonii (Scincidae) and Heteronota bineoi (Gekkonidae). A further Isospora sp. is mentioned from Phyllurus cornutus (Gekkonidae). A table of comparative data of lacertilian Isospora is given, and also a host check-list.
I would like to thank Miss J. Arnold of the Department of Zoology, University of Western Australia, for her identification of many of the lizards, and Miss S. Curtis for her drawings. Finally I wish to thank Dr H. M. D. Hoyte, Department of Parasitology, University of Queensland, for his interest, and helpful criticism of the manuscript.
Coprological examination of 83 East African chameleon specimens revealed 32.5% prevalence of coccidian parasites. Six species are described as new: Eimeria tilburyi n. sp. from Chamaeleo jacksonii has cylindrical oocysts, 28.9 (26-33) x 16.0 (14-18) microm and occasionally a small polar granule. Sporocysts are oval to ellipsoidal, 10.6 (9-12) x 7.2 (6-8) microm, without Stieda and substieda bodies; endogenous stages were found in the gall bladder. Oocysts of Eimeria largeni n. sp. from Chamaeleo gracilis are broadly cylindrical, 31.2 (29.5-34) x 19.3 (18.5-20) microm, with 1-3 polar granules. Sporocysts are oval, 10.2 (10-11) x 7.6 (7-8.5) microm, without Stieda and substieda bodies. Eimeria bohemii n. sp. from Chamaeleo melleri has cylindrical oocysts, 25.0 (24-26) x 14.0 (13-15) microm, without a polar granule. Sporocysts are broadly oval, 9.4 (9-10) x 6.5 (6-7) microm, without Stieda and substieda bodies. Isospora wildi n. sp. from Chamaeleo dilepis has subspherical to broadly oval oocysts, 25 (22-28) x 21.4 (18-24) microm, with a smooth wall 1 microm thick. Sporocysts are broadly oval to ellipsoidal, 12.3 (12-13) x 9.7 (9-10) microm, with Stieda and substieda bodies. Oocysts of Isospora necasi n. sp. from C. melleri are subspherical to broadly oval, 26.6 (21-30) x 24.3 (20-27) microm, with a velvetlike wall 2 microm thick. Sporocysts are broadly ellipsoidal, 12.8 (12-14) x 9.8 (9-10) microm, with slightly pointed end and with Stieda and substieda bodies. Oocysts of Isospora munriyu n. sp. from C. jacksonii are spherical to subspherical, 23.6 (21.5-25) x 21.9 (21-23) microm, with a finely granulated wall 1.5 microm thick. Sporocysts are broadly ellipsoidal, 12.4 (12-13) X 8.7 (8-10) microm, with Stieda and substieda bodies.
At the joint meeting of the 8th International Coccidiosis Conference and the Annual Scientific Meeting of the Australian Society for Parasitology in Palm Cove, Australia, in July 2001, a Controversial Roundtable was held on 'New classification of coccidia'. The aim of this Roundtable was to stimulate and encourage discussion and debate on current classification schemes for the group of parasitic protozoa known as the eimeriid coccidia. In the past, such classifications have been based only on phenotypic characters such as morphology, ultrastructure, life cycles, and host specificity. However, over the past 10-15 years, molecular phylogenetic studies on taxa of the eimeriid coccidia have revealed that several of the families, subfamilies, and genera that have been erected based on non-molecular characters are paraphyletic. Therefore, this Roundtable was an important forum for initial discussions on how a new and more comprehensive classification of the eimeriid coccidia, which takes into consideration both phenotypic and molecular characters, can be devised. The stimulus came from invited speakers who gave introductions into selected areas of taxonomy and classification. Following these introductions, a more general discussion with the audience addressed potential steps that may be taken in future work. This review is the immediate outcome of the Roundtable. It describes advantages and disadvantages of the use of phenotypic or molecular characters as the base for taxonomic schemes for eimeriid coccidia. It gives specific examples for drawbacks of current classifications based only on phenotypic characters as well as potential pitfalls associated with the use of only molecular phylogenies. It addresses current controversies as well as rules of taxonomy and nomenclature relevant for the eimeriid coccidia. Finally, it recommends the establishment of an international group of scientists to meet on a regular basis, stimulate further discussions, and give direction on how the final goal, i.e. a proposal for a revised, and widely accepted, classification of the eimeriid coccidia, may be achieved.
The phylogenetic relationships of Goussia janae and Choleoeimeria sp. were analyzed using the small subunit ribosomal RNA gene (SSU rDNA). This is a first attempt to study the molecular phylogeny of coccidian genera parasitizing strictly poikilotherm hosts. The biliary Eimeria-like coccidia of reptiles classified into the genus Choleoeimeria form a sister clade to the family Eimeriidae, which confirms the separate generic status of the genus Choleoeimeria. The position of Goussia is less robustly resolved, since it forms a trichotomy with the Eimeriidae and Sarcocystidae, or alternatively constitutes the earliest branch of the coccidian lineage. Morphological similarities, namely the extracytoplasmic location of the endogenous stages, and the presence of sutures in the sporocyst wall are discussed in the context of the traditional classification of eimeriids. In contrast to the morphology-based systematics, the monophyly of Goussia and Choleoeimeria is not supported by the SSU rDNA data.
Eimeria jamescooki sp. n. was recovered from the skink Cryptoblepharus virgatus (Garman) found on the grounds of James Cook University, Townsville (type locality), North Queensland, Australia. Oocysts were 17.5-25.0 (22.1 +/- 1.9) x 15-22.5 (17.7 +/- 1.6) microm and sporocysts 6.25-10.0 (7.9 +/- 1.15) x 3.75-6.25 (5.3 +/- 1.0) microm in size. Endogenous stages are described from histological material examined by light microscope and by transmission electron microscope. Both merogony stages and gamonts were found to develop in the cytoplasm of the anterior gut mucosal epithelium. Meront progeny were comprised of 10 to 21 merozoites. Premature macrogamonts were elongate; some host cells contained two elongate macrogamonts. Unique to the presently described species were the Golgi "plaques" and an enclosure of tubuli. Mature macrogamonts and young oocysts ranged in size from 14 x 7 to 21 x 11 microm and contained two types of wall-forming bodies, canaliculi and amylopectin granules. Differentiating microgamonts conformed in fine structure with that observed in other eimerians. Their sizes increased from 15.4 x 4.2 to 28 x 8.4 microm while dividing to over 70 nuclei, which formed a corresponding yield of microgametes.
The parasites of the stumpy-tail lizard, Tachysaurus rugosus
- T H Johnson
Johnson, T.H., 1932. The parasites of the stumpy-tail lizard, Tachysaurus rugosus.
Trans. R. Soc. S. Aust. 56, 62-70.
Coccidia of the world
- D W Duszynski
- L Couch
- S J Upton
Duszynski, D.W., Couch, L. Upton, S.J., 2000. Coccidia of the world. Available at:
<http://biology.unm.edu/biology/coccidia/home.html>.