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.

A RETROSPECTIVE ANALYSIS OF MORBIDITY AND MORTALITY IN CAPTIVE BLUE-CROWNED LAUGHING THRUSHES (PTERORHINUS COURTOISI): 1998-2018.

The blue-crowned laughingthrush (BCLT) (Pterorhinus courtoisi) is a species of critically endangered passerine that is part of a Global Species Management Plan and experiences high mortality rates in some collections. Complete necropsy and medical records from 15 European institutions that housed BCLT between 1998 and 2018 were assessed to evaluate morbidity and mortality in the captive population. Medical records for 407 BCLT were received; a total of 191 morbidity events were recorded from 111 individual BCLT. The most common cause of morbidity was coccidial disease, including systemic isosporosis (30.4%, n = 58). Age was a significant factor contributing to mortality, with 53% of deaths occurring between 0 and 14 d old and 78% by 1 yr of age. The most common cause of death was trauma (22.8%, n = 31), followed by systemic isosporosis (22%, n = 30). Of the 343 deceased birds for which records were provided, 50.4% had a necropsy performed and 40.5% had histopathology carried out postmortem. Based on these findings, BCLT should be managed carefully to mitigate risk of trauma, and screening for isosporosis should be performed. Institutions should carry out standardized necropsies and histopathology on every BCLT that dies in their collection to elucidate the etiology of disease in this critically endangered species.

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.

SYSTEMIC ISOSPORIASIS (ATOXOPLASMOSIS) IN PASSERINE BIRDS AT THE ZOOLOGICAL SOCIETY OF LONDON, LONDON ZOO.

Infection with systemic Isospora species (systemic isosporiasis [SI]) is common in passerine birds and may cause substantial mortality in zoological collections. Ten years of postmortem records of 26 species of captive, nonnative passerine birds maintained at the Zoological Society of London, London Zoo, plus seven free-ranging species found dead within the zoo, were reviewed to assess cause of death and occurrence of SI (presence of merozoites in tissue impression smears and/or polymerase chain reaction [PCR] testing for Isospora DNA). The records of 287 juveniles and adults were reviewed, of which 161 had SI test results. The most common cause of death was physical (trauma, predation, drowning, and hypothermia), diagnosed in 39.0% of cases. Virulent SI was considered the cause of death in only nine individuals from five species (3.1% of all cases, 5.6% of tested birds). However, merozoites were recorded in 36.0% of the 150 individuals examined cytologically (representing 18 of the 33 species), while 45.3% of 53 spleen samples (14 species) were positive for Isospora DNA. Test agreement for the 42 birds tested by both methods was 69.0%. Assuming that the PCR result was correct in these, 37.9% of the 161 birds (21 species) were positive for SI at the time of death. These figures might underestimate prevalence because of poor DNA preservation and low numbers of individuals of some species tested. Eight new 28S rDNA sequences and 12 new internal transcriber spacer 1/2 sequences were amplified. Sequences from individuals of the same host species clustered together, suggesting a single Isospora species, and there was no evidence of overlap among hosts. These results confirm that systemic infection with Isospora species in zoo passerines is generally of low pathogenicity and most likely coevolved with their hosts. Severe disease may occur, however, with overwhelming exposure, secondary to immunosuppression, or following coinfection with another pathogen.

Antibiotic treatment increases yellowness of carotenoid feather coloration in male greenfinches (Chloris chloris).

Carotenoid plumage coloration is an important sexually selected trait in many bird species. However, the mechanisms ensuring the honesty of signals based on carotenoid pigments remain unclear. It has recently been suggested that intestinal integrity, which is affected by gut parasites and microbiota and influences nutrient absorption and acquisition, mediates the relationship between carotenoid ornamentation and individual quality. Here, we test whether carotenoid plumage coloration in greenfinches (Chloris chloris) is affected by the treatment of an antibiotic or an antiparasitic drug. We captured wild greenfinches (N = 71) and administered anticoccidial medication toltrazuril (TOLTRA) to one group, antibiotic metronidazole (METRO) to the second group to target trichomonosis, and the third group received no medication. In the METRO group, feathers grown during the experiment had significantly higher chroma of yellow parts, but there was no effect of TOLTRA on feather chroma. The results suggest that METRO increased the efficiency of carotenoid modification or deposition to the feathers rather than nutrient acquisition and/or freed energy resources that could be invested in coloration. Alternatively, though not measured, METRO might have affected microbial community and host physiology as microbial metabolites can modulate mitochondrial and immune function.

Morphological and molecular characterization of Isospora amphiboluri (Apicomplexa: Eimeriidae), a coccidian parasite, in a central netted dragon (Ctenophorus nuchalis) (De Vis, 1884) in Australia.

An Isospora species, Isospora amphiboluri, originally described by Canon in 1967 and later by McAllister et al. (1995), was isolated from a central netted dragon (Ctenophorus nuchalis) housed at a wildlife rehabilitation centre in Perth, Western Australia. Sporulated oocysts of Isospora amphiboluri (n = 30) are spherical, 24.2 (26.5-23.0) µm in length and 23.9 (22.4-25.9) µm in width, with a shape index of 1.01. The bilayered oocyst wall is smooth and light-yellow in color. Polar granule, oocyst residuum and micropyle are absent. The sporocysts are lemon-shaped, 15.7 (15.2-18.0) × 10.2 (8.9-11.2) µm, with a shape index (length/width) of 1.53. Stieda and substieda bodies are present, the Stieda body being small and hemidome-shaped and the substieda half-moon-shaped. Each sporocyst contains four vermiform sporozoites arranged head to tail. The sporozoites are 11.7 (9.9-16.2) × 3.0 (2.4-3.5) µm, with a shape index (length/width) of 3.87. A sporocyst residuum is present. Sporozoites contain a central nucleus with a finely distributed granular residuum. Comparison of oocyst measurements and their features with other valid Isospora species from hosts in the Agamid family confirmed that this Isospora species is Isospora amphiboluri. Molecular characterization of I. amphiboluri at the 18S rRNA and MTCOI loci showed the highest similarity with I. amphiboluri from the central bearded dragon, 99.8% and 99.7% respectively. This is the first report of I. amphiboluri from a central netted dragon in Australia.

Distribution, redescription, and molecular identification of Isospora striata McQuistion et al. 1997 (Eimeriidae), from woodcreepers (Dendrocolaptidae) in South America.

Woodcreepers are passerines of the family Dendrocolaptidae, which have a high forest dependency. The current work aimed to redescribe Isospora striata McQuistion et al. 1997, from two new hosts in protected areas in Brazil, revealing new localities of parasitism, in addition to providing preliminary genotypic identifications via sequencing of the mitochondrial cytochrome c oxidase subunit 1 (COI) gene from both host species. Isospora striata has oocysts that are subspheroidal to ovoidal, 19.4 × 16.8 µm with smooth wall. Oocyst residuum is absent, but micropyle and polar granules are present. Sporocysts are ovoidal, 13.6 × 8.3 µm, with both Stieda and sub-Stieda bodies. Sporocyst residuum is present and sporozoites with refractile body, nucleus, and striations. The morphological study and the 100% similarity in sequencing of the COI gene between samples of different dendrocolaptid species confirmed the identification of a single species, supporting the identification of I. striata in the Brazilian Atlantic forest and consequently the wide distribution of this coccidian species in the Neotropical Region.

Morphological and molecular description of a new species of Isospora (Apicomplexa) from a New Holland honeyeater (Phylidonyris novaehollandiae).

A new Isospora species is described from New Holland honeyeaters (Phylidonyris novaehollandiae). Sporulated oocysts (n = 25) were characterised as subspheroidal, 29-32 × 28-31 (29.8 × 29.4); length/width (L/W) ratio 1.01-1.02 (1.01). Wall bi-layered, 1.3-1.6 (1.5) thick, outer layer smooth, c.2/3 of total thickness. Micropyle and oocyst residuum absent, but usually two polar granules are present. Sporocysts (n = 25) ovoidal, 18-19 × 12-14 (18.4 × 12.3); L/W ratio 1.42-1.53 (1.50). Stieda body present, flattened, c.0.5 deep × 2.5 wide; sub-Stieda present, rounded, c.2.5 deep × 3.5 wide; para-Stieda body absent; sporocyst residuum present, usually a distinctly irregular body consisting of numerous small granules that appear to be membrane-bound. Sporozoites vermiform, with robust anterior and posterior refractile bodies. Molecular characterization was conducted at the 18S and 28S ribosomal RNA and the mitochondrial (mt) cytochrome oxidase (COI) loci. Phylogenetic analysis of genomic 18S and mt COI sequences indicated that Isospora phylidonyrisae n. sp. was genetically similar to Isospora coronoideae, isolated from an Australian raven (Corvus coronoides) in Western Australia, with a 99.3% and 98.4% homology, respectively. The 28S rRNA sequence was most similar to Isospora anthochaerae (KF766053) and Isospora manorinae (KT224381), both with a 98.2% genetic similarity. Based on morphological and genetic data, this isolate is a new species of Isospora, which is named Isospora phylidonyrisae n. sp. after its host.

A New Isospora (Apicomplexa: Eimeriidae) from the Summer Tanager, Piranga rubra (Aves: Passeriformes: Cardinalidae), in Oklahoma.

The summer tanager, Piranga rubra (L., 1758) is a medium-sized songbird formerly belonging to the tanager family Thraupidae but now has been placed within the family Cardinalidae. Nothing is known about the coccidian parasites of this stunningly colorful bird. Feces from 2 P. rubra found dead in McCurtain County, Oklahoma were collected and examined for coccidia; 1 was found to be passing a new species of Isospora. Oocysts of Isospora mccurtainensis n. sp. are subspheroidal to ovoidal with a smooth bilayered wall, measure (length × width [L × W]) 21.7 × 19.5 µm, and have a L/W ratio of 1.1; a micropyle and oocyst residuum were absent but a bilobed and refractile polar granule is present. Sporocysts are ellipsoidal and measure 13.9 × 8.6 µm, L/W 1.6; a knoblike Stieda body is present as well as a distinct sub-Stieda body. The sporocyst residuum is composed of a granular compact cluster with a dense, irregular mass of granules lying between and dispersed among the sporozoites. This is the first coccidian reported from P. rubra and, most important, only the first known from the Cardinalidae in the mainland of the United States.

Morphological and genetic characterization of the first Isospora species (I. lugensae n. sp.) from a Kerguelen petrel (Lugensa brevirostris).

A new coccidian species, Isospora lugensae n. sp., was described from a single Kerguelen petrel (Lugensa brevirostris). Sporulated oocysts (n = 25) were characterized as subspheroidal to ellipsoidal measuring 24-25 µm × 21-23 µm (24.8 × 22.2 µm) in length/width (L/W), respectively, with a ratio of 1.07-1.14 µm (1.12). They contained a bi-layered wall with a thickness of 0.8-1.2 µm (1.0) and the outer layer smooth, with c.2/3 of total thickness. The oocyst contained two polar granules with both micropyle and oocyst residuum absent. Ovoidal sporocysts (n = 25) measured 15-16 µm × 10-11 µm (15.7 × 10.8 µm) in L/W, with a ratio of 1.41-1.49 µm (1.46). A flattened to knob-like Stieda body was present (c.0.5 µm deep × 2.5 µm wide) as well as a rounded to trapezoidal sub-Stieda (c.1.5 µm deep × 3.0 µm wide); however, no para-Stieda body was detected. The sporocyst residuum was composed of scattered spherules of different sizes, while vermiform sporozoites contained a refractile body, nucleus and visible striations. Analysis of the full-length mitochrondrial (mtDNA) genome revealed 3 protein-coding genes, (CytB, COI and COIII), 18 LSU and 14 small subunit (SSU) rDNA fragments, without transfer RNA genes with a total length of 6257 bp. Phylogenetic analysis of genomic SSU ribosomal sequences indicated that Isospora lugensae n. sp. is genetically similar to Eimeria reichenowi, isolated from a red-crowned crane (Grus japonensis) from Japan, with a 96.6% homology. The mtDNA sequence is most similar to Isospora serinuse with a 95.8% genetic similarity. Based on morphological and molecular data, this isolate is a new species of coccidian parasite that to date has only been found in a Kerguelen petrel.

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.

Morphological and molecular characterization of Cystoisospora laidlawi oocysts (Apicomplexa: Eimeriidae) in farmed American mink (Neovison vison) in Denmark.

From a longitudinal survey conducted on 30 Danish mink farms in 2016, 11.0% of faecal samples (456/4140) were positive for Cystoisospora laidlawi oocysts by microscopy, with 60% (189/315) of mink being positive at least once during the study period. Morphological analysis of sporulated oocysts identified Cystoisospora oocysts measuring 34.3 × 29.5 µm with an oocyst length/width (L/W) ratio of 1.2. The morphological features of the oocysts were identical to Isospora laidlawi previously morphological identified in farmed mink from Denmark and elsewhere. Phylogenetic analysis of 18S rDNA sequences (1221 bp) from three positive mink indicated that Cystoisospora from mink shared the highest genetic similarity to C. canis from a Canadian dog (99.6%). The phylogenetic analysis placed Cystoisospora from mink in a clade with other Cystoisospora isolates.

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.

A New Isosporan (Apicomplexa: Eimeriidae) from Wood Thrush, Hylocichla mustelina (Aves: Passeriformes: Turdidae), in Oklahoma.

The wood thrush, Hylocichla mustelina, is a North American passerine bird closely related to other thrushes and is widely distributed across North America. Nothing is known of the coccidian parasites of this bird. Feces from a single H. mustelina found dead in McCurtain County, Oklahoma were collected and examined for coccidia; it was found to be passing a new species of Isospora. Oocysts of Isospora gmelini n. sp. are subspheroidal to ellipsoidal with a smooth bilayered wall, measure (length [L] × width [W]) 19.5 × 16.5 µm, and have a L/W ratio of 1.2; a micropyle and oocyst residuum were absent but polar granule(s) are present. Sporocysts are ellipsoidal to elongate and measure 13.4 × 8.9 µm, L/W 1.5; a buttonlike Stieda body is present, but sub-Stieda and para-Stieda bodies are absent. The sporocyst residuum is composed of a compact spheroid with a dense, irregular mass of finer granules lying between and dispersed among the sporozoites. Although several isosporans have been reported from other turdid birds, mainly from Brazil and Costa Rica, this is the initial coccidian reported from H. mustelina and only the second known from the Turdidae in the mainland of the United States.

Morphological and molecular identification of Isospora massardi Lopes, Berto, Luz, Galvão, Ferreira & Lopes, 2014 (Chromista: Miozoa: Eimeriidae) from thrushes Turdus spp. (Passeriformes: Turdidae) in South America.

In the current work, Isospora massardi Lopes, Berto, Luz, Galvão, Ferreira & Lopes, [10] is identified from white-necked thrushes Turdus albicollis Vieillot, 1818, rufous-bellied thrushes Turdus rufiventris Vieillot, 1818 and from a new host, the yellow-legged thrush Turdus flavipes (Vieillot, 1818) in a new locality, the Itatiaia National Park, in Southeastern Brazil, providing a preliminary genotypic characterization via sequencing of the mitochondrial cytochrome c oxidase subunit 1 (COI) and 18S small subunit ribosomal RNA genes. The oocysts and sporocysts of I. massardi of the current study are morphologically similar to the original description and are uniform in the proportionality of width on length, but exhibited different patterns of size associated with each host species. Furthermore, a genotypic difference of 3% was found in the COI sequences from T. flavipes and T. albicollis. Therefore, an ecological discussion is introduced aimed at associating these morphometric and genotypic differences with an ongoing speciation process.

Isospora svecica sp. n. (Apicomplexa: Eimeriidae), a new species of coccidium from the white-spotted bluethroat Luscinia svecica cyanecula (Aves: Passeriformes: Muscicapidae).

Using a combination of morphological and molecular data, we describe a new apicomplexan parasite, Isospora svecica sp. n., from the white-spotted bluethroat, Luscinia svecica cyanecula, from the Czech Republic. Oocysts were found in its intestinal tract. Sporulation was exogenous and took 1-3 days. The oocysts were slightly ellipsoidal, of average size 26.17 × 20.33 µm, with a smooth bilayered wall. Micropyle, oocyst residuum, and polar granules were absent. Sporocysts were bottle-shaped, of an average size of 18.82 × 8.82 µm, with a thin, colourless wall. A conspicuous knob-like Stieda body was present. Substieda body was barely visible. Sporocyst residuum was present in the form of granules of various sizes. Sporozoites were banana-shaped and contained large anterior and small posterior refractile bodies. Partial DNA sequences of three genes were obtained from oocysts of Isospora svecica sp. n., being most closely related to other isosporans described from passerines. Little is known about the parasites of the avian family Muscicapidae, including coccidia, a highly prevalent parasitic protist group in all vertebrate classes. Only six species of the genus Isospora have so far been described in Muscicapidae, together with several "Isospora sp." that in fact most likely represent Isospora lacazei. The newly described Isospora svecica sp. n. differs morphologically from other coccidia reported from muscicapid birds, and represents the first coccidian species described from Luscinia svecica.

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).

Isospora borbai n. sp. (Chromista: Apicomplexa: Eimeriidae) from gnateaters Conopophaga spp. (Passeriformes: Tyranni: Conopophagidae) in South America.

BACKGROUND: The gnateaters Conopophaga spp. are insectivorous passerines commonly observed in high and humid forests, where they remain lodged in thin branches and, sometimes, they fly to the ground to catch insects. The insectivorous feeding habit is related to low prevalence and density of coccidians in passerines; however, several coccidian species are recorded for families of insectivorous passerines. PURPOSE: This study aimed to examine the feces from gnateaters Conopophaga spp. captured in the municipality of Barra Mansa and in the Itatiaia National Park, State of Rio de Janeiro, Southeastern Brazil, to determine what coccidian parasites were present. METHODS: Nine gnateaters were captured with mist nets. Coccidian oocysts were recovered from the fecal samples by flotation in Sheather's saturated solution. Morphological observations, line drawings, photomicrographs and measurements were made in optical microscopy and digitally edited. The molecular analysis included the study of the sequence of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene, with phylogenetic reconstructions based on the neighbor-joining and maximum likelihood analysis. RESULTS: Four Conopophaga spp. were positive for oocysts. An Isospora sp. considered as new to science is described and identified from Conopophaga melanops (Vieillot, 1818) and Conopophaga lineata (Wied, 1831). Isospora borbai n. sp. has oocysts that are subspheroidal, 17-22 × 15-22 (20.2 × 19.1) µm, with rough, bilayered wall, c.1.7 µm thick. Micropyle present, but without micropyle cap. Oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal, 12-15 × 8-11 (14.1 × 9.1) µm. The Stieda body is knob-like to half-moon-shaped and sub-Stieda body is rounded. Sporocyst residuum is present, composed of scattered spherules of different sizes. Sporozoites are vermiform with refractile body and nucleus. Molecular analysis at the cox1 gene exhibited similarity greater than 99% with Isospora spp. isolates from other Neotropical passerine birds. CONCLUSION: Based on the morphological and molecular features, I. borbai is considered as new to science and the first coccidian species recorded from Conopophagidae.

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).

A review of Cystoisospora felis and C. rivolta-induced coccidiosis in cats.

Until the discovery of Toxoplasma gondii oocysts in cat feces in 1970, little was known of coccidiosis in cats. Until 1970, three coccidian parasites based on different sized oocysts were recognized, the parasite with large oocysts (∼40 µm long and called Isospora felis), medium sized oocysts (∼25 µm long, called Isospora rivolta), and small sized oocysts (14 µm or less, called Isospora bigemina) were known and they were considered not host-specific. Later, it was demonstrated that these parasites were host-specific and had also extra-intestinal stages. The Isospora bigemina turned out to be more than 25 organisms belonging to T. gondii, Hammondia spp., Sarcocystis spp., Besnoitia spp., and Neospora spp.; these subjects have been reviewed previously in detail. The present paper summarizes biology of Isospora felis, and I. rivolta (now transferred to genus Cystoisospora), including taxonomy, life cycle, diagnosis, and treatment. Re-excretion of T. gondii oocysts from chronically infected cats after superinfection with Cystoisospora felis oocysts is discussed. There are only two species of Cystoisospora species in cats, C. felis and C. rivolta; Isospora novocati and Cystoisospora frenkeli named for I. rivolta-like parasites of cats are considered synonym of C. rivolta. Clinical coccidiosis occurs more commonly in recently weaned kittens and C. felis infections are more prevalent than C. rivolta.