Isospora coerebae Berto, Flausino, Luz, Ferreira and Lopes, 2010

Ortúzar-Ferreira, Carlos Nei, Andrade, Lucas De Assis S., Genovezoliveira, Jhon Lennon, Oliveira, Mariana S., Mello, Ericson R., Cardozo, Sergian V., Oliveira, Águida A., Lima, Viviane M., Ferreira, Ildemar & Berto, Bruno P., 2022, Molecular identification of Isospora coerebae Berto, Flausino, Luz, Ferreira & Lopes, 2010 (Chromista: Miozoa: Eimeriidae) from the bananaquit Coereba flaveola (Linnaeus, 1758) (Passeriformes: Thraupidae: Coerebinae) from Brazil, Zootaxa 5168 (1), pp. 83-91 : 85-86

Isospora coerebae Berto, Flausino, Luz, Ferreira and Lopes, 2010

Host: Bananaquit Coereba flaveola (Linnaeus, 1758) ( Passeriformes : Thraupidae : Coerebinae )

Locality: Private Natural Heritage Reserve of Porangaba (22°48’29.83’’S; 43°49’38.77’’W), Municipality of Itaguaí , State of Rio de Janeiro, Southeastern Brazil .

Specimens: Photomicrographs are deposited 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 115/2021. Photovouchers of the host specimens are deposited in the same collection.

Representative DNA sequence: DNA amplification of the COI1 and COI2 genic regions showed clear bands around ~250 bp and ~650 bp, respectively. Representative sequences were deposited in the GenBank database under the accession numbers: OK194671 (COI1); and OK194672 (COI2).

Site of infection: Unknown.

Prevalence: 100% (1/1).

Sporulation: Exogenous. All oocysts were passed in the feces unsporulated and were fully sporulated by day 7 in K 2 Cr 2 O 7 solution at room temperature (20–25°C).

Morphology ( Fig 1 A-F): Oocyst (n = 15) sub-spherical, 22−27 × 22−25 (24.4 × 22.9); length/width (L/W) ratio 1.0−1.1 (1.07). Wall bi-layered, smooth outer wall about 2/3 total thickness, 1.5−1.8 (1.7). Micropyle, polar granules and oocyst residuum absent. Sporocyst elongate ovoidal, 16−19 × 10−11 (17.6 × 10.5); L/W ratio 1.6−1.8 (1.67). Stieda body present, prominent and rounded, 1.3−1.5 × 1.9−2.3 (1.4 × 2.1). Sub-Stieda body present, short and wide, 1.0−1.6 × 3.1−3.7 (1.3 × 3.5). Para-Stieda body absent. Crystalloid body sometimes present in the center of the sporocyst. Sporocyst residuum present, composed of many scattered granules of different sizes. Sporozoites vermiform, with a prominent posterior refractile body.

Remarks: The oocysts recovered from the bananaquit in the current work are morphologically equivalent to the original description of I. coerebae , which have a typical and easily identifiable morphology, mainly in the Stieda and Sub-Stieda bodies ( Berto et al. 2010). Table 1 compares the morphology and morphometry of the oocysts from the current work with those from the original description of I. coerebae . The typical morphology of the Stieda and Sub-Stieda bodies of I. coerebae are the basis of differentiation from another congeneric species, Isospora cagasebi Berto, Flausino, Luz, Ferreira and Lopes, 2008 , which has the same host- and locality-types: C. flaveola in the Marambaia Island (Berto et al. 2008) ( Table 1 ). However, in the current work no oocyst of I. cagasebi was observed, which, despite being similar in some characteristic features to I. coerebae , their sporocysts have knob-like Stieda body and prominent Sub-Stieda body, while I. coerebae has rounded Stieda body and short and wide Sub-Stieda body ( Berto et al. 2010).

Phylogenetic analysis: Phylogenetic analysis included sequences from coccidians available in GenBank ( Figs. 2 ; 3 ). Toxoplasma gondii (Nicolle and Manceaux, 1908) was used as the outgroup. In the phylogenetic analysis based on the COI1 gene ( Fig. 2 ), I. coerebae was recovered in a clade with the highest similarity of 99% with Isospora sepetibensis Berto, Flausino, Luz, Ferreira and Lopes, 2008 from black-goggled tanagers Trichothraupis melanops (Vieillot, 1818) of the Itatiaia National Park, which is located in the mountainous region in the interior of Southeastern Brazil. In the COI2 based phylogenetic analysis ( Fig. 3 ), I. coerebae sat in a large clade with Isospora spp. from passerines of North America, Europe and Asia, with the highest similarity of 98% with Isospora greineri Hafeez, Stasiak, Delnatte, El-Sherry, Smith and Barta, 2014 from superb starlings Lamprotornis superbus Rüppell, 1845 at the Toronto Zoo, Toronto, Canada.

Figures

FIGURE 1. Photomicrographs of sporulated oocysts of Isospora coerebae, a coccidium species recovered from the bananaquit Coereba flaveola from Southeastern Brazil. Note the posterior refractile body (prb), crystalloid body (cb), inner (il) and outer (ol) layer of the oocyst wall, sporocyst residuum (sr) and the Stieda (sb) and sub-Stieda (ssb) bodies. Scale-bar = 10 µm.

FIGURE 2. Maximum likelihood tree estimated from the COI1 gene sequences of coccidian species. Numbers at the nodes show posterior probabilities under the Bayesian Inference analysis/bootstrap values derived from Maximum Likelihood analysis. Scale bar represents the number of nucleotide substitutions per site.

FIGURE 3. Maximum likelihood tree estimated from the COI2 gene sequences of coccidian species. Numbers at the nodes show posterior probabilities under the Bayesian Inference analysis/bootstrap values derived from Maximum Likelihood analysis. Scale bar represents the number of nucleotide substitutions per site.