Isospora sepetibensis Berto, Flausino, Luz, Ferreira, Lopes, 2008

Genovez-Oliveira, Jhon Lennon, Cardozo, Sergian V., De Oliveira, Águida A., De Lima, Viviane M., Ferreira, Ildemar & Berto, Bruno P., 2019, Morphological and Molecular Identification of Isospora sepetibensis (Chromista: Miozoa: Eimeriidae) from a New Host, Trichothraupis melanops (Passeriformes: Thraupidae: Tachyphoninae) in South America, Acta Protozoologica 58 (1), pp. 17-23 : 18-19

Isospora sepetibensis Berto, Flausino, Luz, Ferreira, Lopes, 2008 ( Fig. 1 )

Description of sporulated oocyst: Oocyst shape (n = 18) sub-spherical to elongate ovoidal; 22–29 × 19–22 (25.9 × 20.7) length/width (L/W) ratio 1.1–1.4 (1.26). Wall bi-layered, 1.1–2.0 (1.3) thick, outer layer smooth, c. 2/3 of total thickness. Micropyle and oocyst residuum absent, but one or two polar granules are present.

Description of sporocyst and sporozoites: Sporocysts (n = 18), ellipsoidal, 15–18 × 9–11 (16.8 × 10.3); L/W ratio 1.5–1.8 (1.65). Stieda body present, knob-like, 1.1–1.3 (1.2) high, 2.0–2.2 (2.1) wide; sub-Stieda body present, large to trapezoidal or, occasionally, irregular, 1.2–2.3 (1.7) high, 2.7–3.5 (3.1) wide; para-Stieda body absent. Sporocyst residuum present, consisting of numerous small granules dispersed between the sporozoites or as a distinctly sub-spherical body that appear to be membrane-bounded, 5.5–6.7 (6.1). Sporozoite vermiform with one posterior refractile body, centrally located nucleus and striations.

Host: Trichothraupis melanops (Vieillot, 1818) ( Passeriformes : Thraupidae : Tachyphoninae).

Locality: Itatiaia National Park (22°26’17.00”S, 44°37’33.00”W), Southeastern Brazil .

Specimens: Photomicrographs and oocysts in 2.5% K 2 Cr 2 O 7 solution ( Williams et al. 2010) are deposited at the Museu de Zoologia at the Universidade Federal Ru- ral do Rio de Janeiro, Brazil, under accession number MZURPTZ2019014. Photomicrographs are also de- posited and available (http://r1.ufrrj.br/labicoc/colecao. html) in the Parasitology Collection of the Laboratório de Biologia de Coccídios, at UFRRJ, under repository number 92/2019. Photographs of the host specimens are deposited in the same collection.

Site in host: Unknown.

Prevalence: 67% (15 out of 10 birds infected).

Representative DNA sequence: Representative cox1 sequence is deposited in the GenBank database under the accession number MK682606 .

Phylogenetic analysis: The amplification of the DNA from the fifteen oocysts of I. sepetibensis recovered from T. melanops showed a clear band of c. 250 bp. The phylogenetic analysis was constructed with 33 sequences of Isospora spp. closest to I. sepetibensis available on GenBank ( Fig. 2 ). Eimeria tenella (Railliet, Lucet, 1891) was used as the outgroup. Isospora sepetibensis sat in a large group with the highest similarity of 98.1% with an Isospora sp. reported as pseudoparasite of bank voles Myodes glareolus (Schreber, 1780) in Czech Republic ( Trefancová et al. 2019). It was close to the clade with Isospora isolates from the spectacled warbler Sylvia conspicillata Temminck, 1820 in Macaronesia ( Illera et al. 2015); and also was close to the clade with Isospora spp. recently sequenced from Neotropical passerines ( Silva-Carvalho et al. 2018a, 2018b; Rodrigues et al. 2019). Subsequently, a subset with only 215 bp long cox1 gene sequences was constructed ( Fig. 3 ). In this analysis, Isospora sepetibensis sat in the same clade of Isospora spp. from Neotropical passerines, with the highest similarity of 98.5% with Isospora lopesi Silva-Carvalho & Berto, 2018 ( Silva-Carvalho et al. 2018a).

Figures

Fig. 1. Photomicrographs of sporulated oocysts of Isospora sepetibensis, a coccidium species recovered from the black-goggled tanager Trichothraupis melanops. Note the inner (il) and outer (ol) layer of the oocyst wall, nucleus (n), polar granule (pg), Stieda body (sb), sub- Stieda body (ssb), sporocyst residuum (sr), striations (str) and the refractile body (rb). Sheather’s sugar solution. Scale-bar: 10 µm.

Fig. 2. Maximum likelihood tree estimated from the cox1 sequences. Numbers at nodes represent bootstrap support (1,000 replicates; only values> 50% shown) for Neighbor-Joining and Maximum Likelihood, respectively. The scale-bar represents the number of nucleotide substitutions per site.

Fig. 3. Maximum likelihood tree estimated from the 215 bp long cox1 sequences. Numbers at nodes represent bootstrap support (1,000 replicates; only values> 50% shown) for Neighbor-Joining and Maximum Likelihood, respectively. The scale-bar represents the number of nucleotide substitutions per site.