MOLECULAR CHARACTERIZATION OF ISOSPOROID COCCIDIA (ISOSPORA AND ATOXOPLASMA SPP.) IN PASSERINE BIRDS

Isospora and Lankesterella Parasites (Eimeriidae, Apicomplexa) of Passeriform Birds in Europe: Infection Rates, Phylogeny, and Pathogenicity

Wild birds are common hosts to numerous intracellular parasites such as single-celled eukaryotes of the family Eimeriidae (order Eucoccidiorida, phylum Apicomplexa). We investigated the infection rates, phylogeny, and pathogenicity of Isospora and Lankesterella parasites in wild and captive passerine birds. Blood and tissue samples of 815 wild and 15 deceased captive birds from Europe were tested using polymerase chain reaction and partial sequencing of the mitochondrial cytochrome b and cytochrome c oxidase I and the nuclear 18S rRNA gene. The infection rate for Lankesterella in wild birds was 10.7% compared to 5.8% for Isospora. Chromogenic in situ hybridization with probes targeting the parasites' 18S rRNA was employed to identify the parasites' presence in multiple organs, and hematoxylin-eosin staining was performed to visualize the parasite stages and assess associated lesions. Isospora parasites were mainly identified in the intestine, spleen, and liver. Extraintestinal tissue stages of Isospora were accompanied by predominantly lymphohistiocytic inflammation of varying severity. Lankesterella was most frequently detected in the spleen, lung, and brain; however, infected birds presented only a low parasite burden without associated pathological changes. These findings contribute to our understanding of Isospora and Lankesterella parasites in wild birds.

Mate choice is affected by parasite infestation rate of the choosing individual as well as of potential mating partners

Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioral traits being used. However, there is little experimental evidence on how the parasite's burden of the choosing individual is integrated into the mate-choice process and how it affects decision-making, especially in relation to parasite infestation of potential mates. Thus, the aim of our study was to determine whether female house sparrows Passer domesticus adjust their mate preference according to their own as well as the parasite load of prospective partners. To do this, we experimentally manipulated female parasite load and determined their mate preferences prior to and after parasite treatment. We manipulated the chronic coccidian parasite burden of females either by initiating the acute infection phase via re-infecting them with coccidian or by temporally reducing the parasite load of coccidia. We then measured the effect of this manipulation on mate preference by presenting females with a choice of four stimuli: three males with similar ornaments, but unmanipulated, naturally varying chronic coccidiosis levels, and an unmanipulated control female. Additionally, we recorded some males' behavior in relation to their infection status pointing toward an increased or reduced interest in mating. We found that females preferred highly infested males prior to manipulation, regardless of their own infestation level. However, after manipulation, infested females avoided highly infested males probably in response to the deterioration of their health condition by parasites. Our study suggests that mate-choice decisions are more complex when they are mediated by parasites. The implications of parasites for evolutionary theories of sexual signaling and mate choice are discussed.

THE PHARMACOKINETICS AND PHARMACODYNAMICS OF ORAL PONAZURIL IN THE TREATMENT OF SYSTEMIC ISOSPOROSIS IN PASSERINE BIRDS

Systemic isosporosis, previously atoxoplasmosis, is a significant cause of mortality in juvenile passerine birds. Recommended treatment regimens are empiric and vary in efficacy. The goal of this study was to determine the pharmacokinetics and pharmacodynamics of ponazuril for treatment of systemic isosporosis. Ponazuril, diluted with water to create an oral suspension (50 mg/ml), was administered (100 mg/kg) to 72 European starlings (Sturnus vulgaris) by a single dose via direct oral gavage (n = 24), a single dose injected into superworm larvae (Zophobas morio; n = 24), or a daily dose mixed with commercial dog food to top-dress feed for 5 d (n = 24). Peak plasma concentrations were 5.84, 2.46, and 9.13 µg/ml for the direct gavage, injected larvae, and top-dressed feed groups, respectively. With repeated dosing, mean plasma concentrations from the top-dressed feed group were maintained between 8.12 to 13.11 µg/ml. Results suggested ponazuril at a dosage of 100 mg/kg administered via direct gavage or top-dressed feed, but not via injected larvae, would exceed the concentrations needed to inhibit merogony of other apicomplexan parasites in cell culture (5 µg/ml). To assess the pharmacodynamics of this dose, seven passerine birds, red-vented bulbuls (Pycnonotus cafer; n = 2), blue-grey tanager (Thraupis episcopus; n = 1), and red-capped cardinals (Paroaria gularis; n = 4), were identified as shedders of systemic Isospora spp. via fecal qPCR. Birds were then treated with ponazuril (100 mg/kg) daily on top-dressed feed for 14 d. Fecal shedding was assessed via qPCR for 6 wk from the initiation of treatment. Treatment was associated with reduction in proportions of fecal shedding during the treatment period and the week following treatment, but shedding resumed in all birds by the end of sampling. Results support that treatment of breeding birds with 100 mg/kg ponazuril could reduce the shedding of active oocysts and decrease risk of clinical infection in susceptible juveniles.

Morphological and molecular characterization of Isospora elliotae n. sp. (Apicomplexa: Eimeriidae) from the Australian magpie Gymnorhina tibicen (Latham, 1801) (Passeriformes: Artamidae) in Western Australia

A new coccidian species, Isospora elliotae n. sp., from the Australian magpie Gymnorhina tibicen (Latham, 1801) in Western Australia, is described and characterized morphologically and molecularly. Microscopic analysis of a faecal sample identified subspheroidal oocysts (n = 20), 20-22 × 18-20 (20.7 × 18.7); length/width (L/W) ratio 1.05-1.14 (1.10). Wall bi-layered, 1.0-1.3 (1.2) thick, outer layer smooth, c. 2/3 of total thickness. Micropyle and oocyst residuum absent, but usually two polar granules are present. Sporocysts (n = 28) ovoidal, 12-13 × 9-11 (12.6 × 9.7); L/W ratio 1.22-1.35 (1.30). Stieda body present, flattened to half-moon-shaped, c. 0.5 deep × 2.0 wide; sub-Stieda indistinct or barely discernible, c. 1.0 deep × 2.5 wide; para-Stieda body absent; sporocyst residuum present, composed of granules dispersed among the sporozoites. Sporozoites vermiform, with anterior and posterior refractile bodies and nucleus. Segments of three gene loci (18S rRNA, 28S rRNA and COI) were sequenced and I. elliotae n. sp. exhibited 99.8% genetic similarity to Isospora sp. MAH-2013a (KF648870) followed by 99.7% genetic similarity to Isospora neochmiae (Yang, Brice & Ryan, 2016) (KT224380) at the 18S rRNA gene locus. It shared 97.0% genetic similarity with an unnamed Isospora sp. (AY283852) at the 28S rRNA gene locus and it also shared the highest genetic similarity of 99.8% with the unnamed Isospora sp. from an American crow (OL999120) at the COI gene locus. Based on morphological and molecular data, this isolate is a new species named as I. elliotae n. sp.

Host specificity of passerine Lankesterella (Apicomplexa: Coccidia)

Lankesterella parasites are blood coccidians that have recently gained attention as their records in common passerine species emerge. To date, their occurrence has been molecularly confirmed in several passerine genera, mainly among members of the families Paridae and Acrocephalidae. Despite their relatively high prevalence in some host populations, their life cycles remain unclear, mosquitoes or mites being the proposed vectors. The aim of this study was to reveal Lankesterella host specificity, focusing mainly on parasites of tit and warbler species (families Paridae and Acrocephalidae). We have determined the 18S rRNA gene sequences of Lankesterella from 35 individuals belonging to eight different host species. Phylogenetic analysis revealed that passerine Lankesterella are host-specific, with specificity at the host genus or species level. Besides Lankesterella, Isospora sequences were obtained from avian blood as well, pointing out the need for barcoding.

Novel viral and microbial species in a translocated Toutouwai (Petroica longipes) population from Aotearoa/New Zealand

BACKGROUND

Translocation is a common tool in wildlife management and its implementation has resulted in many conservation successes. During translocations, any associated infectious agents are moved with their wildlife hosts. Accordingly, translocations can present a risk of infectious disease emergence, although they also provide an opportunity to restore natural infectious communities ('infectome') and mitigate the long-term risks of reduced natural resistance.

METHODS

We used metatranscriptomic sequencing to characterise the cloacal infectome of 41 toutouwai (North Island robin, Petroica longipes) that were translocated to establish a new population within the North Island of New Zealand. We also screened for pathogenic bacteria, fungi and parasites.

RESULTS

Although we did not detect any known avian diseases, which is a positive outcome for the translocated toutouwai population, we identified a number of novel viruses of interest, including a novel avian hepatovirus, as well as a divergent calici-like virus and four hepe-like viruses of which the host species is unknown. We also revealed a novel spirochete bacterium and a coccidian eukaryotic parasite.

CONCLUSIONS

The presumably non-pathogenic viruses and microbial species identified here support the idea that most microorganisms likely do not cause disease in their hosts, and that translocations could serve to help restore and maintain native infectious communities. We advise greater surveillance of infectious communities of both native and non-native wildlife before and after translocations to better understand the impact, positive or negative, that such movements may have on both host and infectome ecology.

The performance of field sampling for parasite detection in a wild passerine

Parasites can impact the behavior of animals and alter the interplay with ecological factors in their environment. Studying the effects that parasites have on animals thus requires accurate estimates of infections in individuals. However, quantifying parasites can be challenging due to several factors. Laboratory techniques, physiological fluctuations, methodological constraints, and environmental influences can introduce measurement errors, in particular when screening individuals in the wild. These issues are pervasive in ecological studies where it is common to sample study subjects only once. Such factors should be carefully considered when choosing a sampling strategy, yet presently there is little guidance covering the major sources of error. In this study, we estimate the reliability and sensitivity of different sampling practices at detecting two internal parasites-Serratospiculoides amaculata and Isospora sp.-in a model organism, the great tit Parus major. We combine field and captive sampling to assess whether individual parasite infection status and load can be estimated from single field samples, using different laboratory techniques-McMaster and mini-FLOTAC. We test whether they vary in their performance, and quantify how sample processing affects parasite detection rates. We found that single field samples had elevated rates of false negatives. By contrast, samples collected from captivity over 24 h were highly reliable (few false negatives) and accurate (repeatable in the intensity of infection). In terms of methods, we found that the McMaster technique provided more repeatable estimates than the mini-FLOTAC for S. amaculata eggs, and both techniques were largely equally suitable for Isospora oocysts. Our study shows that field samples are likely to be unreliable in accurately detecting the presence of parasites and, in particular, for estimating parasite loads in songbirds. We highlight important considerations for those designing host-parasite studies in captive or wild systems giving guidance that can help select suitable methods, minimize biases, and acknowledge possible limitations.

Mitochondrial Gene Diversity and Host Specificity of Isospora in Passerine Birds

Isospora infections are common in both wild and captive passerine species. Many bird species have been shown to have co-evolved with a particular species of Isospora. Disease can range from subclinical to severe and fatal, making infection and transmission of this parasite a concern for birds under managed care, particularly in institutions housing endangered species for breeding and reintroduction purposes. Whether birds in mixed-species enclosures represent a risk factor for severe isosporiasis due to infection with non-host-adapted strains is of concern for institutions managing these populations. To begin answering this question, we sought to characterize the host-specificity of Isospora spp. in a large number of passerine birds via retrospective sequencing of mitochondrial gene cytochrome c oxidase subunit I (COI). Despite outliers, Isospora sequences largely grouped by host species and/or host family. Additional research is warranted into the degree of interspecies transmission and host-switching of Isospora parasites, and risk factors for the development of severe disease in passerine birds.

Unique Isospora-associated histologic lesions in white-rumped shama (Copsychus malabaricus)

Twenty-one white-rumped shamas (19 necropsied, 2 biopsied) (Copsychus malabaricus) housed at the San Diego Zoo between 1992 and 2020 were diagnosed with Isospora infection based on evaluation of histologic sections. Review of these cases revealed a consistent histologic lesion characterized by nodular aggregates of atypical epithelioid macrophages containing few intracytoplasmic protozoa, with or without lymphocytic infiltrates. Of the 19 necropsied cases, 16 (84%) had systemic lesions variably affecting the liver, spleen, gastrointestinal tract, lung, pancreas, connective tissues, or bone marrow, while all 21 diagnosed cases had skin involvement. The findings suggest that white-rumped shamas have a unique inflammatory response to isosporosis with a predilection for the skin. Skin may be a diagnostically sensitive sampling site for histologic diagnosis of Isospora in this species.

The First Isospora Species (Apicomplexa: Eimeriidae) Described from the Northern Yellow-Shafted Flicker (Colaptes auratus luteus) in Ontario, Canada

PURPOSE

Members of the genus Isospora commonly infect a wide variety of wild birds. By combining morphometric and genetic data, we are able to differentiate and describe a new apicomplexan parasite, Isospora picoflavae n. sp., from the Northern Yellow-shafted Flicker (Colaptes auratus luteus) in Ontario, Canada.

METHODS

Unsporulated oocysts were observed in intestinal contents obtained during necropsy; these oocysts completed exogenous sporulation within 7 days at room temperature. Complete nuclear 18S rDNA and complete mitochondrial genome sequences were obtained from this previously undescribed Isospora sp. to compare with related coccidia.

RESULTS

Sporulated oocysts were subspherical in shape measuring an average of 22.7 × 21.7 μm (n = 53; mean shape index 1.05) containing a near-spherical polar granule. Sporocysts were ovoidal to ellipsoidal in shape, measuring an average size of 17.0 × 10.5 μm (n = 9; mean shape index 1.62). Sporocyst residuum was concentrated in an irregular, spherical mass in the middle of each sporocyst. The isolated oocysts differed morphologically from other Isospora species reported to infect members of the family Picidae. Based on phylogenetic analyses using either combined nuclear 18S rDNA and mitochondrial cytochrome c oxidase I (COI) sequences or complete mitochondrial genome sequences, this Isospora sp. n. isolated from the Northern Flicker grouped within a clade containing Isospora species described from various passeriform hosts.

CONCLUSION

Based on combined morphological and molecular data, the oocysts found in the gastrointestinal contents of Colaptes auratus luteus represent a new species of Isospora named herein as Isospora picoflavae n. sp.

Hyaloklossia Labbé, 1896 (Alveolata: Apicomplexa) in frogs: Description of a new species and proposing a new subfamily to accommodate these enigmatic parasites

Hyaloklossia Labbé ,1896 (Alveolata: Apicomplexa) is a monotypic genus of renal coccidia found in anurans, particularly in the edible frog Pelophylax kl. esculentus (Amphibia: Anura: Ranidae), distributed in different parts of Europe. Here we propose a new Hyaloklossia species from the Tokyo daruma pond frog, Pelophylax porosus porosus. The coccidium detected in the renal tissue of P. p. porosus shared some morphological characteristics with the type species, Hyaloklossia lieberkuehni (Labbé, 1894), reported from P. kl. esculentus. However, in addition to size differences in several oocyst and sporocyst features between these parasites, phylogenetic analysis of gene fragments from two nuclear ribosomal loci and the mitochondrial cytochrome c oxidase subunit 1, exposed distinct genetic differences between H. lieberkuehni and our new species. Although our analysis validated the monophyly of Hyaloklossia with some members of the Toxoplasmatinae Biocca, 1957, Cystoisosporinae Frenkel et al., 1987, and Eumonosporinae Chou et al., 2021 (Sarcocystidae Poche, 1913), comparison of genetic differences between Hyaloklossia species from P. p. porosus and H. lieberkuehni revealed the presence of a greater number of polymorphisms than that observed when comparing inter-species (Heydornia spp., Besnoisita spp.) or inter-genus (Toxoplasma vs. Neospora, Neospora vs. Hammondia, and Neospora vs. Heydornia) variabilities among members of the Sarcocystidae. This indicates that Hyaloklossia, as re-erected and defined by Modrý et al. (2001, Int. J. Syst. Evol. Microbiol. 51, 767–772), with its homoxenous life cycle, requires placement in its own subfamily. Thus, we propose a new subfamily, Hyaloklossiinae n. subfam., to accommodate two species, H. lieberkuehni from Europe and Hyaloklossia kasumienesis n. sp. which we describe here from P. p. porosus in Japan.

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Hyaloklossia was detected from the kidney of Pelophylax porosus porosus (Amphibia: Anura).

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The species was described as Hyaloklossia kasumiensis n. sp.

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This is a new host record for Hyaloklossia and also the first report in Asia.

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Hyaloklossiinae, was proposed as a new subfamily in the Sarcocystidae.

Detection of Eumonospora henryae (Apicomplexa: Sarcocystidae) from Falco columbarius (Falconiformes: Aves): Comparison of host-parasite phylogram and comments on the family Sarcocystidae Poche, 1913

The genus Eumonospora Allen, 1933 (Apicomplexa: Sarcocystidae), an avian coccidia, is characterized by monosporocystic and octasporozoic oocysts without Stieda and substieda bodies. Some members of Eumonospora, which infect several raptor species, exhibit high levels of pathogenicity, making eumonosporiosis the leading cause of death in captive-bred raptors. The host specificity of these species appears to be mesostenoxenous, as evidenced by unsuccessful transmission between different orders of avian hosts. However, several studies have detected Eumonospora spp. in taxonomically distant avian hosts, indicating that some of these species may be euryxenous. In the current study, diarrheic fecal examination of a captive-bred juvenile merlin (Falconiformes: Aves) in Tokyo, Japan, was conducted, and a large number of oocysts were morphologically and molecularly identified as E. henryae (Yakimoff and Matschulsky, 1932), a coccidia species reported only in Strigiformes. This is a new recorded host for this coccidia. Phylogenetic analyses via Bayesian inference and maximum likelihood methods using concatenated genomic datasets consisting of nuclear 18S rDNA, nuclear 28S rDNA and mitochondrial cytochrome C oxidase subunit 1 gene, revealed a well-supported monophyletic clade of Eumonospora spp. belonging to the family Sarcocystidae Poche 1913, which largely corresponded to the avian host phylogram. Therefore, based on distinguishable oocyst morphology, a new subfamily, Eumonosporinae, within the family Sarcocystidae, is proposed, and a reconsideration of the definition of Sarcocystidae is suggested. Further molecular characterization of this emerging pathogen, as well as clarification of its complete life cycle, including cyst-forming ability, is required for more appropriate generic assessment.

Morphological and molecular characterization of a new species of Isospora Schneider, 1881 (Apicomplexa: Eimeriidae) from the western wattlebird Anthochaera lunulata Gould in Western Australia

A new coccidian species, Isospora lunulatae n. sp., from the western wattlebird Anthochaera lunulata Gould in Western Australia is described and characterised molecularly. Microscopic analysis of a faecal sample identified subspheroidal oöcysts measuring 27–34 × 26–31 (30.6 × 29.4) μm (n = 20), with a length/width (L/W) ratio of 1.0–1.1 (1.0). Oöcysts have a bi-layered wall, 0.9–1.2 (1.0) μm thick; the outer layer is smooth, representing c.2/3 of total thickness. Micropyle and oöcyst residuum are both absent, but a polar granule is present. Sporocysts are ovoidal, 17–19 × 10–12 (18.3 × 10.7) μm, with a L/W ratio of 1.6–1.8 (1.7) and occupying about 21% of the area (each one) within the oöcyst. Stieda body is flattened to rounded, measuring on average 0.9 × 1.8 μm; sub-Stieda body is rounded to rectangular, measuring on average 1.5 × 2.6 μm; para-Stieda body is absent. Sporocyst residuum has an irregular shape consisting of numerous granules and appears membrane-bound. Sporozoites are vermiform 12.8 × 3.0 μm on average, with prominent striations at the more pointed end and two refractile bodies below striations. Segments of three gene loci (18S rRNA, 28S rRNA and cox1) were sequenced and I. lunulatae n. sp. exhibited 99.6% genetic similarity to Isospora phylidonyrisae Yang, Brice, Berto & Ryan, 2021 at the 18S rRNA gene locus, 99.8% genetic similarity to Isospora anthochaerae Yang, Brice & Ryan, 2014 and shared a 98.1% genetic similarity with Isospora manorinae Yang, Brice, Jian & Ryan, 2016 at the cox1 gene locus. Morphological and molecular data support the distinct species status of the new species.

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Description of Isospora lunulatae n. sp. from the western wattlebird Anthochaera lunulata.

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Morphology study: most close to I. phylidonyrisae from the New Holland honeyeater Phylidonyrisnovaehollandiae.

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Genetic study: similar to I. phylidonyrisae (18S: 99.6%), I. anthochaerae (28S: 99.8%) and Isospora manorinae (cox1: 98.1%).

Detection and characterization of the Isospora lunaris infection from different finch hosts in southern Iran

This study was conducted to investigate the Isosporoid protozoan infections in finch types. Fecal samples were collected from marketed domestic Java sparrows (Lonchura oryzivora), colored and white Zebra finch (Taeniopygia guttata), and European goldfinch (Carduelis carduelis) in southern Iran. The coccidial oocysts were recovered and investigated according to the morphological features and the ribosomal gene markers. Additionally, a challenge infection was conducted with 5 × 10⁴ and 5 × 10³ sporulated oocysts in four java sparrows to estimate the clinical manifestations. Based on the morphology, the oocysts of Isospora lunaris were identified in all sampled bird types; however, the molecular method revealed the isolates had considerable similarities with some of Isospora and systemic Isospora-like organisms named as Atoxoplasma. Phylogenetic data also constructed an Atoxoplasma/Isospora clade with high sequence identities. High dose of the challenge with the parasite led to severe depression and sudden death, but it did not coincide with remarkable lesions and parasitic invasion in visceral organs. Contrary to molecular results, this feature is consistent with the common Isospora infections in passerines and differs from those described for Atoxoplasma species. Because of the prevalence, possibility of transmission, and clinical consequences, preventive measures are necessary to avoid outbreaks of isosporoid infections among finch type birds.

A QPCR ASSAY AND TESTING GUIDELINES FOR THE MOLECULAR DIAGNOSIS OF SYSTEMIC ISOSPOROSIS (FORMERLY ATOXPLASMOSIS) IN PASSERINE BIRDS

Systemic isosporosis (formerly atoxoplasmosis), is a protozoal infection that causes death in nestling and fledgling passerine birds impacting ex situ breeding and reintroduction programs. Because current antemortem diagnostic tests lack sensitivity, a qPCR was developed for detection of Isospora spp. using primers and a fluorescent-tagged MGB probe targeting the large subunit (28s) ribosomal RNA gene (assay efficiency = >100%; sensitivity = <1 dsDNA copy). The assay was used to screen postmortem frozen or formalin-fixed paraffin-embedded tissue samples from passerine birds (n = 24; 12 with confirmed systemic isosporosis), whole blood and feces (n = 38) from live passerines, and other tissues infected with phylogenetically similar protozoa. The qPCR identified Isospora sp. DNA in tissues from 21/24 birds including 12/12 birds with cytologically-histologically confirmed infection (100% sensitivity) and 9/12 birds lacking microscopic organisms. The assay also amplified Eimeria sp. DNA; however, sequence analysis ruled out infection in the passerine cases. Blood and/or feces were positive in 30/38 birds, and in only 7/38 birds, blood and feces both contained Isospora sp. DNA. Finally, the qPCR was utilized to screen 30 consecutive daily fecal samples from live passerines (n = 20) to determine optimal sampling protocols. One or more of the daily fecal samples were positive in all 20 birds. In individual birds, the interval between positive qPCR amplification results ranged from 0 to 23 days, with an average of 5.85 days. Simulated application of 13 potential sample collection schedules was used to identify the sensitivity of repeated testing for identification of infected birds. Increased sampling days resulted in higher sensitivity but increased both cost and animal handling requirements. Based on statistical analysis and clinical considerations, the testing recommendation for detection of fecal shedding was collection and assay of five consecutive daily fecal samples, which had an average diagnostic sensitivity of 0.86.

Clinical and Pathological Aspects of Systemic Isospora Infection in Blue-crowned Laughing Thrushes (Garrulax courtoisi) at Jersey Zoo

Based on a review of species mortalities, systemic Isospora species was identified as the primary cause of death in 22% (19 of 87) of blue-crowned laughing thrushes (BCLTs; Garrulax courtoisi) at the Jersey Zoo between 1997 and 2016. Fifty-eight percent of the affected birds were between 1 and 2 years old, and in 89% of cases, death occurred between August and December. Abnormal clinical findings in BCLTs with Isospora species infections included hepatomegaly and pectoral muscle myositis in 79% of the cases. The results of diagnostic blood testing in 90% of infected BCLTs 30 days before death were consistent with a severe leukocytosis with greater than 20% of mononuclear cells infected by merozoites. The most common lesions identified during gross necropsy examination were splenomegaly (100%), hepatomegaly (95%), and multifocal, raised, white foci in pectoral (84%) and heart (79%) muscle. Lymphohistiocytic inflammation was identified in the liver, heart, spleen, lung, striated muscle, and kidney tissue of birds with positive results for Isospora species. Merozoites were often observed in spleen, liver, pectoral muscle, and hearts of infected BCLTs. Polymerase chain reaction diagnostic testing that targeted the cytochrome c oxidase subunit, followed by Sanger sequencing, was used to confirm Isospora species in all 14 birds tested. Of samples tested, the highest genetic correlation was with GenBank accession number KT203397 (Isospora species JRB-2016 mitochondrion).

Investigation of systemic isosporosis outbreaks in an aviary of greenfinch (Carduelis chloris) and goldfinch (Carduelis carduelis) and a possible link with local wild sparrows (Passer domesticus)

CASE REPORT

An outbreak of systemic isosporosis caused mortalities in greenfinches (Carduelis chloris) and goldfinches (Carduelis carduelis) kept in an aviary in the western suburbs of Melbourne. The following year, a further outbreak in the same aviary occurred in a different flock of goldfinches. At the time of the second outbreak, dead and sick common sparrows (Passer domesticus) discovered near the aviary were also found to have systemic isosporosis.

METHOD

The systemic isosporosis was investigated and described using histopathology, electron microscopy and sequence analysis of the 18s gene.

RESULTS

Isospora spp. infecting the greenfinch and the goldfinch caused significant thickening of the duodenal lamina propria. Measurements in the goldfinches showed an inverse correlation coefficient between the thickening of the duodenum and the weightof the birds. Electron microscopy confirmed the presence of Isospora spp. within lymphocytes migrating into the lamina propria of the duodenum. Analysis of the 18s sequence discovered two different gene sequences across the three species of birds that didn't completely match any sequences previously deposited in GenBank.

CONCLUSION

Although the sparrows were found to have died from causes other than systemic Isospora, molecular studies of samples from their liver revealed the presence of an Isospora with 18s gene sequence identical to that found in the captive greenfinches.

Molecular identification of Eimeria hestermani and Eimeria prionotemni from a red-necked wallaby (Macropodidae; Macropus rufogriseus) in Japan

To date, more than 50 Eimeria spp. have been isolated from marsupials of the family Macropodidae. Although 18 species of Eimeria have been previously detected from multiple animal species belonging to the genus Macropus of the family, limited genetic analyses of the parasites are available, and their pathogenicity remains unclear. Here, we report the isolation of Eimeria spp. from a zoo specimen of red-necked wallaby (Macropodidae; Macropus rufogriseus). Specifically, two distinct types of Eimeria oocysts were recovered, one from the feces before treatment with an anthelmintic and the second from the intestinal contents after death of the animal. The oocysts obtained from the two sources were morphologically identified as E. hestermani and E. prionotemni, respectively. We successfully determined partial gene sequences from the two isolates, including segments of the 18S rRNA genes, and for the first time have used phylogenetic analyses of these sequences to assign the species to distinct clades. In combination with further genetic data, these results are expected to help elucidate the pathogenicity and host ranges of Eimeria spp. within the respective family and genus.

Avian Papilloma and Squamous Cell Carcinoma: a Histopathological, Immunohistochemical and Virological study

In this retrospective study, we describe the histopathological findings in seven papillomas and 45 squamous cell carcinomas (SCCs) from psittacine birds, raptors and domestic fowl. The age of affected birds ranged from 3 to 40 years, with median age significantly higher in psittacines (P = 0.014). The majority of tumours were located in the skin (24/52, 46.2%) or uropygial gland (10/52, 19.2%). Thirty of the SCCs (66.7%) were well differentiated and 15 (33.3%) were poorly-differentiated. SCCs exhibited a significantly higher degree of nuclear pleomorphism (P = 0.005) and a greater proportion were ulcerated (P = 0.001) compared with papillomas; however, there was no significant difference in mitotic count (MC) or inflammation score. The expression of cyclo-oxygenase (COX)-2 and E-cadherin was investigated by immunohistochemistry. The COX-2 total score (TS) was significantly higher in SCCs compared with papillomas (P = 0.002), but the difference between COX-2 TS of well- and poorly-differentiated SCCs was not significant. COX-2 labelling was predominantly cytoplasmic, but some tumours had concurrent membranous and/or perinuclear labelling. SCCs with membranous labelling had a significantly higher MC (P = 0.028). A significantly higher proportion of SCCs were negative for E-cadherin compared with papillomas (P = 0.042), but there was no significant difference between well- and poorly-differentiated SCCs. Fourteen papillomas and SCCs from psittacines were also tested by polymerase chain reaction for the presence of Psittacus erithacus papillomavirus 1 and Psittacid herpesvirus 1, but all samples tested negative. We demonstrate for the first time the expression of COX-2 and E-cadherin in avian tissues, and suggest that these markers may be useful in differentiating papillomas from SCCs, particularly when sample size is small.

Isospora coronoideae n. sp. (Apicomplexa: Eimeriidae) from the Australian raven (Corvus coronoides) (Passeriformes: Corvidae) (Linnaeus, 1758) in Western Australia

A new Isospora (Apicomplexa: Eimeriidae) species is described from an Australian raven (Corvus coronoides) in Western Australia. Sporulated oocysts (n = 21) are ovoid, 21.2 (18.4-23.9) μm in length and 18.8 (16.9-20.6) μm in width, with a shape index of 1.13. The bi-layered oocyst wall is smooth and colourless, 1.2 μm thick. A polar granule and oocyst residuum is present, but the micropyle is absent. The sporocysts are ovoid-shaped, 16.3 (13.7-18.9) × 10.7 (8.4-12.9) μm, with a shape index (length/width) of 1.52. Stieda and substieda bodies are present, the Stieda body being small and hemidome-shaped and the substieda being indistinct. Each sporocyst with four vermiform sporozoites arranged head to tail. The sporozoites are crescent-shaped, 9.0 (8.9-9.2) × 2.7 (2.3-3.0) μm, with a shape index (length/width) of 3.33. The sporocyst residuum is present. The isolated oocysts had different morphological characteristics when compared with all known Isospora spp. The coccidian parasite was analysed at the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) loci. At the 18S locus, I. coronoideae n. sp. exhibited 98.9% similarity to I. neochmiae from a captive-bred red-browed finch (KT224380) and Isospora sp. from domestic pigeons (Columba livia domestica) (AB757860), 98.5% similarity to I. gryphoni (AF080613) from an American goldfinch and 98.3% similarity to I. manorinae (KT224379) from a yellow-throated miner. At the 28S locus, it exhibited 95.4% and 94.8% similarity to I. manorinae (KT224381) and I. anthochaerae (KF766053), respectively. At the COI locus, it exhibited 99.8% and 99.7% similarity to I. butcherae (KY801687) and I. neochmiae (KT224378), respectively. Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora coronoideae n. sp. after its host, the Australian raven (Corvus coronoides) (Passeriformes: Corvidae) (Linnaeus, 1758).

Molecular survey of coccidian infections of the side-blotched lizard Uta stansburiana on San Benito Oeste Island, Mexico

Blood parasites are found in many vertebrates, but the research on blood parasites of lizards is still at its onset. We analyzed blood samples from side-blotched lizards Uta stansburiana from San Benito Oeste Island, Mexico, to test for the presence of hemoparasites. We found a high prevalence (23 out of 27 samples) of a blood parasite of the genus Lankesterella (Coccidia, Eimeriorina, Lankesterellidae) according to phylogenetic analyses of the parasite 18S rRNA gene. Similar parasites (97-99% similarity) have recently been described for Uta stansburiana from California. The parasite 18S rRNA gene showed high variability, both within San Benito and compared to California. The next closest matches of the parasite DNA with 97-98% similarity included a range of different genera (Lankesterella, Schellackia, Eimeria, Isospora and Caryospora). A high uncertainty in the deeper branches of the phylogenetic trees, and many missing links in genetic network analysis, were in line with previous suggestions that the coccidians are an understudied group with large knowledge gaps in terms of their diversity and taxonomy. Further studies are needed to resolve the evolutionary relationships within the Eimeriorina.

Molecular identification of two Eimeria species, E. uekii and E. raichoi as type B, in wild Japanese rock ptarmigans, Lagopus muta japonica

Thus far, two types of Eimeria parasites (E. uekii and type B) have been morphologically identified in wild Japanese rock ptarmigans, Lagopus muta japonica. Although high prevalences were reported for these parasites, genetic analyses have not been conducted. We first clarified the phylogenetic positions of two eimerian isolates using genetic analyses of 18S rRNA and mitochondrial cytochrome c oxidase subunit I gene regions. Consequently, of 61 samples examined, 21 and 11 samples were positive for E. uekii and type B, respectively. Additionally, the infection rate increased in the summer. Molecular analyses revealed both Eimeria isolates formed their own clusters; E. uekii was included in clades of chicken Eimeria and type B was include in clades of turkey Eimeria. Based on our findings in this study and previous data, we herein propose type B as E. raichoi. These genetic data will be helpful to conduct detailed classification and understand the impact of these parasites for conservation of endangered Japanese rock ptarmigans.

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Molecular analyses revealed Eimeria isolates from Japanese rock ptarmigans formed own clades.

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The species was phylogenetically closely related to virulent chicken Eimeria spp.

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Based on morphological data and sequences, Eimeria type B was proposed as a new species E. raichoi.

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These parasites could be the key factor for conservation of the endangered birds.

Pathological and molecular characterization of systemic isosporosis (atoxoplasmosis) in captive green-winged saltator (Saltator similis)

Systemic isosporosis, also called atoxoplasmosis or visceral coccidiosis, is a disease that affects birds in general. Pathogenesis of systemic isosporosis and its etiologic agent have not been well characterized, but taxonomically Atoxoplasma is currently considered a junior objective synonym of Isospora. The present report aimed to describe pathological and molecular findings of systemic isosporosis in captive green-winged saltators (Saltator similis) from the State of Espírito Santo, Brazil. In a commercial breeding facility eleven birds with two to nine months of age died from 2015 to 2016. These birds developed nonspecific clinical signs, including bristly feathers, hyporexia, loss of weight, and apathy. Two birds were necropsied, and grossly there were hepatomegaly, splenomegaly, necrosis of lymphoid follicles, hepatic necrosis, and severe enteritis. Merozoites were observed in the heart, small intestine, proventriculus, brain, liver, spleen, and kidneys. 23 S RNA PCR amplicons from DNA extracted from the liver and the intestinal contents had 99% identity with Atoxoplasma sp., whereas amplicons of mitochondrial cytochrome c oxidase subunit 1 ha d 97% identity with Isospora greineri. In conclusion, this report indicates that systemic isosporosis in green-winged saltator is a disease that affects the spleen, liver, and small intestine, with high mortality for young birds, resulting in significant loses to commercial breeding facilities.

Molecular evidence for host-parasite co-speciation between lizards and Schellackia parasites

Current and past parasite transmission may depend on the overlap of host distributions, potentially affecting parasite specificity and co-evolutionary processes. Nonetheless, parasite diversification may take place in sympatry when parasites are transmitted by vectors with low mobility. Here, we test the co-speciation hypothesis between lizard final hosts of the Family Lacertidae, and blood parasites of the genus Schellackia, which are potentially transmitted by haematophagous mites. The effects of current distributional overlap of host species on parasite specificity are also investigated. We sampled 27 localities on the Iberian Peninsula and three in northern Africa, and collected blood samples from 981 individual lizards of seven genera and 18 species. The overall prevalence of infection by parasites of the genus Schellackia was ∼35%. We detected 16 Schellackia haplotypes of the 18S rRNA gene, revealing that the genus Schellackia is more diverse than previously thought. Phylogenetic analyses showed that Schellackia haplotypes grouped into two main monophyletic clades, the first including those detected in host species endemic to the Mediterranean region and the second those detected in host genera Acanthodactylus, Zootoca and Takydromus. All but one of the Schellackia haplotypes exhibited a high degree of host specificity at the generic level and 78.5% of them exclusively infected single host species. Some host species within the genera Podarcis (six species) and Iberolacerta (two species) were infected by three non-specific haplotypes of Schellackia, suggesting that host switching might have positively influenced past diversification of the genus. However, the results supported the idea that current host switching is rare because there existed a significant positive correlation between the number of exclusive parasite haplotypes and the number of host species with current sympatric distribution. This result, together with significant support for host-parasite molecular co-speciation, suggests that parasites of the genus Schellackia co-evolved with their lizard hosts.

The Evolutionary Biology, Ecology and Epidemiology of Coccidia of Passerine Birds

Coccidia are intracellular parasites of the phylum Apicomplexa that cause a range of pathologies collectively termed coccidiosis. Species of coccidia of commercial importance have been well studied, with the effect of other species on passerine birds receiving increasing attention. In this chapter, we review the literature on coccidia in passerines, with a particular focus on wild populations. The taxonomy and life cycle of passerine coccidia are covered, as is their impact on the health of passerines, their epidemiology and their role in parasite-mediated natural and sexual selection. Coccidia can pose a significant threat to the health of wild passerine populations, and high rates of mortality have been observed in some studies. We examine some of the genetic factors that influence host resistance to coccidia and discuss how these parasites may be important in relation to sexually selected traits. General patterns are beginning to emerge with regard to the epidemiology of the parasites, and the influence of different aspects of the host's ecology on the prevalence and intensity of coccidia is being revealed. We examine these, as well exceptions, in addition to the phenomenon of diurnal oocyst shedding that can bias studies if not accounted for. Finally, we discuss potential future directions for research on coccidia in passerines and the importance of understanding parasite ecology in the management of threatened species.

The complete mitochondrial genome sequences of two Isospora species (Eimeriidae, Eucoccidiorida, Coccidiasina, Apicomplexa) causing coccidiosis in superb glossy starlings, Lamprotornis superbus (Aves: Sturnidae)

Complete mitochondrial genomes are reported for two Isospora species causing systemic coccidiosis in Superb Glossy Starlings (Aves: Sturnidae). The A/T rich (34.7% G/C) genomes were 6223 bp in length for Isospora greineri and 6217 bp for Isospora superbusi. Each encoded 3 protein-coding genes, (COI, COIII and CytB) plus 18 LSU and 14 SSU rDNA fragments. Arrangement of protein- and rRNA-coding regions was identical to known Eimeria sp. mt genomes; start codon usage was conventional. The mitochondrial genome structures of Isospora and Eimeria species are conserved and reflect the close phylogenetic association between these eimeriid genera of apicomplexan parasites.

Deep-sequencing to resolve complex diversity of apicomplexan parasites in platypuses and echidnas: Proof of principle for wildlife disease investigation

The short-beaked echidna (Tachyglossus aculeatus) and the platypus (Ornithorhynchus anatinus) are iconic egg-laying monotremes (Mammalia: Monotremata) from Australasia. The aim of this study was to demonstrate the utility of diversity profiles in disease investigations of monotremes. Using small subunit (18S) rDNA amplicon deep-sequencing we demonstrated the presence of apicomplexan parasites and confirmed by direct and cloned amplicon gene sequencing Theileria ornithorhynchi, Theileria tachyglossi, Eimeria echidnae and Cryptosporidium fayeri. Using a combination of samples from healthy and diseased animals, we show a close evolutionary relationship between species of coccidia (Eimeria) and piroplasms (Theileria) from the echidna and platypus. The presence of E. echidnae was demonstrated in faeces and tissues affected by disseminated coccidiosis. Moreover, the presence of E. echidnae DNA in the blood of echidnas was associated with atoxoplasma-like stages in white blood cells, suggesting Hepatozoon tachyglossi blood stages are disseminated E. echidnae stages. These next-generation DNA sequencing technologies are suited to material and organisms that have not been previously characterised and for which the material is scarce. The deep sequencing approach supports traditional diagnostic methods, including microscopy, clinical pathology and histopathology, to better define the status quo. This approach is particularly suitable for wildlife disease investigation.

Haemoprotozoa: Making biological sense of molecular phylogenies

A range of protistan parasites occur in the blood of vertebrates and are transmitted by haematophagous invertebrate vectors. Some 48 genera are recognized in bood primarily on the basis of parasite morphology and host specificity; including extracellular kinetoplastids (trypanosomatids) and intracellular apicomplexa (haemogregarines, haemococcidia, haemosporidia and piroplasms). Gene sequences are available for a growing number of species and molecular phylogenies often link parasite and host or vector evolution. This review endeavours to reconcile molecular clades with biological characters. Four major trypanosomatid clades have been associated with site of development in the vector: salivarian or stercorarian for Trypanosoma, and supra- or peri-pylorian for Leishmania. Four haemogregarine clades have been associated with acarine vectors (Hepatozoon A and B, Karyolysus, Hemolivia) and another two with leeches (Dactylosoma, Haemogregarina sensu stricto). Two haemococcidian clades (Lankesterella, Schellackia) using leeches and mosquitoes (as paratenic hosts!) were paraphyletic with monoxenous enteric coccidia. Two major haemosporidian clades have been associated with mosquito vectors (Plasmodium from mammals, Plasmodium from birds and lizards), two with midges (Hepatocystis from bats, Parahaemoproteus from birds) and two with louse-flies and black-flies (Haemoproteus and Leucocytozoon from birds). Three major piroplasm clades were recognized: one associated with transovarian transmission in ticks (Babesia sensu stricto); one with pre-erythrocytic schizogony in vertebrates (Theileria/Cytauxzoon); and one with neither (Babesia sensu lato). Broad comparative studies with allied groups suggest that trypanosomatids and haemogregarines evolved first in aquatic and then terrestrial environments, as evidenced by extant lineages in invertebrates and their radiation in vertebrates. In contrast, haemosporidia and haemococcidia are thought to have evolved first in vertebrates from proto-coccidia and then incorporated invertebrate vectors. Piroplasms are thought to have evolved in ticks and diversified into mammals. More molecular studies are required on more parasite taxa to refine current thought, but ultimately transmission studies are mandated to determine the vectors for many haemoprotozoa.

INVESTIGATION OF THE PRESENCE OF ATOXOPLASMA SPP. IN BLUE-CROWNED LAUGHINGTHRUSH (DRYONASTES COURTOISI) ADULTS AND NEONATES

Between 1996 and 2013, 71 blue-crowned laughingthrush (Dryonastes courtoisi) chicks, a small passerine bird endemic to China, were born at Mulhouse Zoo in northeast France. None of them survived past 1 yr, and 82% died between 0 and 6 days old of an unidentified cause and despite an attempt to establish an artificial breeding protocol. Atoxoplasma spp., causing a disease known as systemic isosporosis, is a coccidian parasite that can infect several species of birds. Mulhouse's adult birds were suspected to be infected with Atoxoplasma spp. and to transmit this parasite to their offspring. A treatment with toltrazuril (Baycox® 2.5%) was implemented in the four adult birds. Coprologic examinations were performed before, during, and after the treatment to quantify the parasite load in feces. Polymerase chain reaction (PCR) assays were used to test blood samples from the adult and liver, lung, gizzard, and kidney samples from 10 chicks to detect Atoxoplasma spp. Five of the 10 chicks had some tissue samples positive for Atoxoplasma spp. in at least one of the three repeats of the atoxoplasmosis PCR. An average of 181 Isospora spp. oocysts per gram of feces were found in the group of adults before treatment. This number was reduced to zero 1 wk after the beginning of the toltrazuril treatment. The PCR results suggest a transovarian transmission of Atoxoplasma spp., but further investigation is needed for confirmation. The treatment with toltrazuril appears to allow a significant reduction of the parasite excretion.

Isospora lunaris n. sp. (Apicomplexa: Eimeriidae) from the domestic Java sparrow in Japan

Five individuals of the domestic Java sparrows, Lonchura oryzivora (Aves: Estrildidae), were examined for coccidian parasites. Sporulated oocysts had two sporocysts containing four sporozoites each. Sporulated oocysts (n=30) were spherical, with a two splinter-like polar granules. Oocyst size was 22.1×20.7 (20.0-25.0×20.0-22.5)μm. They had a thick wall that consisted of a pale yellow outer layer and a dark yellow inner layer, and lacked micropyle and residuum. Sporocysts (n=60) were elongated ovoid 14.1×9.8 (12.5-15.0×7.5-10.0)μm, smooth walled, and colorless, with crescent-shaped Stieda and indistinct substieda bodies. Sporocyst residuum was interspersed between sporozoites. Sporozoites were oriented transverse to the sporocyst longitudinal axis. On the basis of morphological data, the species isolated in the present study is a new species of Isospora and propose the name Isospora lunaris n. sp.

Morphological and molecular characterization of Isospora neochmiae n. sp. in a captive-bred red-browed finch (Neochmia temporalis) (Latham, 1802)

A new Isospora (Apicomplexa: Eimeriidae) species is described from a single red-browed finch (Neochmia temporalis) (subspecies N. temporalis temporalis), that was part of a captive population in Western Australia. Sporulated oocysts of this isolate are spherical, 18.3 (18.2-18.9) × 18.2 (18.2-18.6) μm, with a shape index (length/width) of 1.0; and a smooth and bilayered oocyst wall, 1.2 μm thick (outer layer 0.9 μm, inner 0.3 μm). A polar granule is present, but the oocyst residuum and a micropyle are absent. The sporocysts are ovoid-shaped, 13.3 (9.5-16.4) × 8.6 (6.8-10.0) μm, with a shape index of 1.5. An indistinct Stieda body is present, but the substieda body is absent. A sporocyst residuum is present and composed of numerous granules of different size scattered among the sporozoites. Morphologically, the oocysts from this isolate are different from those of all known valid Isospora spp. Molecular analysis was conducted at 4 loci; the 18S and 28S ribosomal RNA (rRNA), the mitochondrial cytochrome oxidase (COI) gene and the heat shock protein 70 (hsp70) gene. At the 18S locus, this new isolate exhibited 99.9%, 99.8%, 99.7%, and 99.5% similarity to I. sp. MAH-2013a from a superb starling (Lamprotornis superbus), I. MS-2003 from a Southern cape sparrow (Passer melanurus), I. sp. Tokyo from a domestic pigeon (Columba livia domestica) and I. MS-2003 from a Surinam crested oropendula (Psarocolius decumanus). At the 28S locus, this new isolate exhibited 99.7% similarity to both an Isospora sp (MS-2003) from a Northern house sparrow (Passer domesticus) and an Isospora sp. (MS-2003) from a Southern cape sparrow. At the COI locus, this new isolate exhibited 98.9% similarity to an Isospora sp. ex Apodemus flavicollis. At the hsp70 locus, this new isolate exhibited 99% similarity to isolate MS-2003 (AY283879) from a wattled starling (Creatophora cinerea). Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora neochmiae n. sp. after its host, the red-browed finch (Neochmia temporalis).

Molecular phylogenetics of eimeriid coccidia (Eimeriidae, Eimeriorina, Apicomplexa, Alveolata): A preliminary multi-gene and multi-genome approach

Coccidia possess three distinct genomes: nuclear, mitochondrial, and plastid. Sequences from five genes located on these three genomes were used to reconstruct the phylogenetic relationships of members of the phylum Apicomplexa: 18S rDNA sequences from the nuclear (nu) genome, partial cytochrome c oxidase subunit I sequences from the mitochondrial (mt) genome, and partial 16S and 23S rDNA sequences and RNA polymerase B sequences from plastid (pl) genomes. Maximum parsimony, maximum likelihood, and Bayesian inference were used in conjunction with nuclear substitution models generated from data subsets in the analyses. Major groups within the Apicomplexa were well supported with the mitochondrial, nuclear, and a combination of mitochondrial, nuclear and concatenated plastid gene sequences. However, the genus Eimeria was paraphyletic in phylogenetic trees based on the nuclear gene. Analyses using the individual genes (18S rDNA and cytochrome c oxidase subunit I) resolved the various apicomplexan groups with high Bayesian posterior probabilities. The multi-gene, multi-genome analyses based on concatenated nu 18S rDNA, pl 16S, pl 23S, pl rPoB, pl rPoB1, and mt COI sequences appeared useful in resolving phylogenetic relationships within the phylum Apicomplexa. Genus-level relationships, or higher, appear best supported by 18S rDNA analyses, and species-level analyses are best investigated using mt COI sequences; for parasites for which both loci are available, nuclear 18S rDNA sequences combined with mitochondrial COI sequences provide a compact and informative molecular dataset for inferring the evolutionary relationships taxa in the Apicomplexa.

The complete mitochondrial genome sequence of an Isospora sp. (Eimeriidae, Eucoccidiorida, Coccidiasina, Apicomplexa) causing systemic coccidiosis in domestic Canaries (Serinus canaria Linn.)

We report a complete mitochondrial genome sequence for an Isospora sp. causing systemic coccidiosis in canaries, Serinus canaria. The A + T rich (65.2%) genome was 6216 bp in length and possessed 3 protein-coding genes, (COI; COIII and CytB), 19 LSU and 14 SSU rDNA fragments, including 1 newly identified putative LSU fragment. Arrangement of coding regions was identical to that of available Eimeria sp. mt genomes and start codon usage for protein-coding genes was conventional. The similar mitochondrial genome sequences and structures of Isospora and Eimeria species confirm the close relationship between these eimeriid genera of apicomplexan parasites.

A new Caryospora coccidian species (Apicomplexa: Eimeriidae) from the laughing kookaburra (Dacelo novaeguineae)

A new Caryospora coccidian species is described from the laughing kookaburra (Dacelo novaeguineae). Sporulated oocysts (n=30) are ovoid in shape with a smooth, colourless, bilayered oocyst wall and measure 31.4×29.3 (30.0-32.0×28.0-31.0) μm with a shape index of 1.1. Oocysts contain one spheroidal to subspheroidal sporocyst, 21.2×20.6 (20.0-24.0×20.0-21.0) μm. A spheroidal shaped sporocyst residuum is present; micropyle, Stieda, substieda and parastieda bodies are absent. Vermiform sporozoites (n=8) are arranged either parallel or randomly in the sporocyst, measuring 17.0×4.8 (16.0-18.0×4.0-6.0) μm, with a L/W ratio of 3.5. There is a large spheroidal, posterior refractile body in the middle of the sporozoite. Morphologically, this new species is most similar to Caryospora. The prevalence of this parasite was 6.7% in birds sampled in the morning and 33.3% from those sampled after midday. Further molecular characterisation was conducted at two loci; the 18S and 28S ribosomal RNA (rRNA). At the 18S locus, the new species of Caryospora was most closely related to Besnoitia besnoiti (99.2% similarity) and Hammondia triffittae (98.8% similarity). Although, no 28S partial sequences from Caryospora were available in GenBank, the highest similarity was with B.besnoiti (91.3%). Based on morphological and molecular data, this coccidian parasite is a new species that to date has not been reported. The new coccidian parasite is named Caryospora daceloe n. sp. after its host D. novaeguineae (the laughing kookaburra).

Description of two new Isospora species causing visceral coccidiosis in captive superb glossy starlings, Lamprotornis superbus (Aves: Sturnidae)

Isospora greineri sp. n. and Isospora superbusi sp. n. are described from captive superb glossy starlings, Lamprotornis superbus, from the Toronto Zoo succumbing to visceral coccidiosis. Sequence data from nuclear 18S recombinant DNA (rDNA) and mitochondrial cytochrome c oxidase subunit I (COI) loci from sporulated oocysts and infected tissues (liver, lung, or spleen) demonstrated two distinct Isospora sp. genotypes that varied in their relative abundance. In the tissues of one affected bird, as well as its associated fecal sample, two distinct COI sequences (1.7% divergence) and two distinct 18S rDNA sequences (0.6% divergence) were found at almost the same abundance; in other specimens, one of the 18S and one of the COI sequences were less abundant than the other. In the tissues of some birds, only a single COI and single 18S sequence were present. In all cases, the same pair of 18S rDNA and COI sequences fluctuated in abundance in parallel, indicating that there were two distinct species present rather than one species with more than one COI or 18S locus. The oocysts of these new species cannot be differentiated morphologically. Sporulated oocysts of both were spherical to subspherical measuring 17.7 ± 0.22 μm by 17.1 ± 0.20 μm with a mean L/W ratio of 1.03 ± 0.004. Sporocysts were ovoid measuring 13.5 ± 0.17 μm by 9.3 ± 0.15 μm with a mean L/W ratio of 1.4 ± 0.02. Sporocysts had a small Stieda body with indistinct sub-Stieda body; each sporocyst had a compact residuum. Two morphologically similar but genetically divergent Isospora species were shown to cause simultaneous enteric and extraintestinal infections in captive superb glossy starlings.

Afternoon shedding of a new species of Isospora (Apicomplexa) in the endangered Regent Honeyeater (Xanthomyza phrygia)

The Regent Honeyeater (Xanthomyza phyrigia) is an endangered Australian bird species. Breeding populations have been established at Australian zoos in support of re-introduction programmes. This species is the host of a new species of Isospora (Apicomplexa). Oocysts are spherical, 25·8 (22·5-28·75) by 23·8 (20-26·25) μm with a colourless to pale yellow smooth wall undergoing rapid exogenous sporulation, 90% sporulated oocysts in 8 h at 20°C. Each oocyst contains 1 polar granule. Sporocysts are ovoid, 18·67 (17-19) by 9·49 (9-10) μm with a flat Stieda body and spherical substieda body devoid of a hyaline body. The asexual stages and sexual phase is within the enterocytes of the duodenum and jejunum. Faeces collected in the morning (AM, n=84) and in the afternoon (PM, n=90) revealed significant diurnal periodicity in oocyst shedding; 21% (18 of 84) of the AM were positive with the mean of 499 oocysts.g-1 compared to the PM with 91% (82 of 90) bird faeces positive with the mean of 129 723 oocysts.g-1. Therefore, parasite checks for these birds should be carried out in the afternoon to obtain an accurate result. The ecological significance of the high parasite burden in captive birds requires further investigation and comparison to the wild counterparts.

Isospora anthochaerae n. sp. (Apicomplexa: Eimeriidae) from a Red wattlebird (Anthochaera carunculata) (Passeriformes: Meliphagidae) in Western Australia

A new species, Isospora anthochaerae n. sp. is described from a Red wattlebird (Anthochaera carunculata). Sporulated oocysts (n=37) are subspherical, with smooth colourless to pale brown bilayered oocyst wall, 0.8 μm thick (outer layer 0·6 μm, inner 0.2 μm thick). Oocyst with 2 spheroidal to subspheroidal sporocysts. Oocyst length, 23.4 μm (20.0-26.0); oocyst width, 20.7 μm (19.0-22.0); oocyst length/width (L/W) ratio, 1.1. Micropyle, oocyst residuum and polar granule are absent. Sporocysts with compact sporocyst residuum and 4 sporozoites. Sporocyst length, 14.5 μm; sporocyst width, 10.1 μm sporocyst L/W ratio, 1.4. Molecular analysis was conducted at four loci; the ribosomal internal transcribed spacer (ITS), the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase gene (COI). At the COI locus, I. anthochaerae n. sp. exhibited 98.5% similarity to Isospora lesouefi from a Regent honeyeater (Xanthomyza phrygia) and 98% similarity with an Isospora sp. (iSAT5) from a blackcap (Sylvia atricapilla). Based on morphological and molecular data, this isolate is a new species of coccidian parasite that to date has only been found in Red wattlebirds.