Hepatic coccidiosis (Eimeria sp) in a wild magpie-lark (Grallina cyanoleuca)

A New Species of Eimeria Schneider, 1875 from the Saffron Finch, Sicalis flaveola (Aves: Passeriformes) in Brazil

PURPOSE

The present study describes a new species of Eimeria found in free-living S. flaveola that inhabit the city of Eugenópolis in the state of Minas Gerais, Brazil.

METHODS

Fecal samples from all captured birds were filtered through double gauze, mixed with 2.5% potassium dichromate (K₂Cr₂O₇), placed in a Petri dish and incubated at 23-28 °C until 70% of the oocysts were sporulated.

RESULTS

Eimeria flaveola n. sp. from the saffron finch, Sicalis flaveola (Aves: Passeriformes), was described in Brazil. Sporulated oocysts are subspherical; 22.67 ± 1.57 (18.47-26.48) × 21.19 ± 1.42 (16.69-24.91) µm; with a shape-index of 1.07 ± 0.05 (1.00-1.25) µm and a smooth, bilayered wall, ~ 1.09 μm. A micropyle and an oocyst residuum are absent, but one polar granule is present. Sporocysts are ovoidal, 14.24 ± 1.71 (9.02-19.33) × 9.98 ± 1.02 (6.80-12.87) μm; with a shape-index of 1.43 ± 0.16 (0.74-2.11). The Stieda body is button-shaped; sub-Stieda body and para-Stieda absent. The sporocyst residuum is formed by a compact rounded mass of granules. The sporozoite is claviform, 11.53 µm in length and 2.84 µm in width, with a refractile body and a nucleus.

CONCLUSIONS

Based on its morphological and morphometric characteristics, we consider E. flaveola a newly identified species.

Molecular and morphological analysis of a Caryospora-like isolate (Apicomplexa: Eimeriidae) from the magpie-lark (Grallina cyanoleuca) (Latham, 1801) in Western Australia

A new Caryospora-like isolate is described from a magpie-lark (Grallina cyanoleuca) in Western Australia. Sporulated oocysts of the Caryospora-like isolate (n = 35) are subspherical with a shape index of 1.13 ((21.5 (19.7-23.6) × 19.0 (18.1-19.8) μm). The bilayered oocyst wall is smooth. Micropyle, polar granule and oocyst residuum are absent. The sporocyst is ellipsoidal, 18.9 (17.2-20.8) × 12.3 (11.9-12.8) μm, with a shape index (length/width) of 1.54. The sporocyst wall is bilayered. Stieda and substieda bodies are present, the Stieda body is small and flattened and the substieda is trapezoidal. Sporocyst with eight sporozoites arranged head to tail. The sporozoites are vermiform, 18.9 (17.2-20.8) × 12.3 (11.9-12.8) μm and have striations at the anterior end. Each sporozoite has both anterior and posterior refractile bodies. A sporocyst residuum is present. Molecular characterization of the isolated Caryospora-like oocysts was conducted at the 18S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) loci. At the 18S rRNA locus, the Caryospora-like isolate exhibited 88.8% to 96.5% similarity with other Caryospora spp. from different hosts. At the COI locus, it showed 91.5% similarity to Caryospora cf. bigenetica JB-2013 (KF859856) from the rattlesnake, Sistrurus catenatus.

Extra-intestinal coccidiosis in the kiwi (Apteryx spp.)

Despite significant conservation intervention, the kiwi (Apteryx spp.) is in serious population decline. To increase survival in the wild, conservation management includes rearing of young birds in captivity, safe from introduced mammalian predators. However, an increase in density of immunologically naïve kiwi increases the risk of exposure to disease, including coccidia. Intestinal coccidiosis has recently been described in the kiwi, and although extra-intestinal coccidiosis was first recognized in kiwi in 1978, very little is known about this disease entity. This study used archived histological tissues and reports from routine necropsies to describe the pathology of naturally occurring extra-intestinal coccidiosis. At least 4.5% of all kiwi necropsied during 1991 to 2011 (n=558) were affected by extra-intestinal coccidiosis, and it is estimated that it caused death in 0.9 to 1.2% of kiwi in the study group. Four forms were recognized: renal, hepatic, and, less commonly, splenic and pulmonary. At necropsy, renal coccidiosis was associated with miliary white streaks and foci through the kidneys, renomegaly, and renal pallor or congestion. Renal meronts and gametocytes were confined to the distal convoluted tubules and collecting ducts, and were associated with renal tubular necrosis and tubular obstruction. Hepatic miliary pinpoint foci were present throughout the hepatic parenchyma associated microscopically with macromeronts measuring 304×227 µm. In two cases, clusters of splenic meronts were identified, and a similar lesion was identified in the pulmonary interstitium of another case. Juvenile, captive kiwi were most often affected with extra-intestinal coccidiosis, illustrating an increased expression of disease with population manipulation for conservation purposes.