Eimeria caviae Sheather, 1924

Flausino, Gilberto, Berto, Bruno P., Mcintosh, Douglas, Furtado, Tassia T., Teixeira-Filho, Walter L. & Lopes, Carlos Wilson G., 2014, Phenotypic and Genotypic Characterization ofEimeria caviae from Guinea Pigs (Cavia porcellus), Acta Protozoologica 53 (3), pp. 269-276 : 271-272

Eimeria caviae Sheather, 1924 ( Figs 1 , 2 )

Species description: Sporulated oocysts are polymorphic, being sub-spherical, ovoidal or ellipsoidal,

measure 20.9 (14–25) × 17.7 (14–21) µm (n = 150) and present shape-index 1.2 (1.0–1.5). They are smooth or slightly rough, with a 1.0 (0.9–1.2) µm thick bi-layered wall. Micropyle and oocyst residuum are absent, but one polar granule is present. Sporocysts are ellipsoidal and measure 10.8 (7–13) × 6.4 (4–9) µm (n = 150). They present shape-index 1.7 (1.2–2.3), are smooth, thin, with single-layered wall. Stieda body is evident and triangular, ~ 1.0 µm high × 2.0 µm wide. The parastieda body is flattened, ~ 0.5 µm high × 2.0 µm wide. Sporocyst residuum is composed of few scattered granules. The sporozoites have a robust posterior refractile body and a centrally located nucleus.

Host: The Guinea pig, Cavia porcellus Linnaeus, 1758 ( Rodentia : Caviidae ).

Locality: Municipality of Seropédica (22°44′29″S and 43°42′19″W) in the State of Rio de Janeiro, Brazil .

Material deposited: Phototypes and line drawings are deposited and available (http://r1.ufrrj.br/lcc) in the Parasitology Collection of the Laboratório de Coccídios e Coccidioses, UFRRJ, located in Seropédica, Rio de Janeiro State, Brazil. The repository number is 54/2014 .

Morphometric characterization: The histograms and linear regression of E. caviae sporulated oocysts can be visualized in Figs 3 and 4, respectively. In the histograms of length, width and shape-index it was observed that the frequencies of the different classes increased and declined gradually; in other words, the oocyst measurements are in smaller quantities in the limits of values and in greater quantity in median values. In relation to linear regression, the R 2 value was lower than 0.4 and the points were distributed distant from the regression line on the graph, which served to demonstrate the polymorphism of the oocysts.

Genotypic characterization: Amplifications using 100fg of DNA as template, generated single amplicons with an approximate size of 350 base pairs (bp). Two individual amplicons were sequenced in both directions and aligned using Sequencher 5.0. To determine the size of the ITS-1 component of the E. caviae amplicon, sequences corresponding to the genes encoding the 18S ribosomal RNA (rRNA) and 5.8S rRNA of Eimeria tenella (GenBank accession number AF026388) were aligned with the E. caviae sequence. This analysis demonstrated that the ITS-1 region was 232 nucleotides in length. The sequence did not demonstrate significant nucleotide similarity with any other sequence deposited in the GenBank, database. The sequence of the entire amplicon (352 bp), was deposited in the GenBank with the accession number (KC484340).

Figures

Fig. 1. Line drawings of sporulated oocysts of Eimeria caviae, a coccidium species recovered from Guinea pigs Cavia porcellus: (A) subspherical, (B) ellipsoidal, and (C) ovoidal oocysts; (D–G) variations of the Stieda bodies; (H–K) variations of the parastieda bodies; (L–M) variations of roughness of the oocyst wall. Scale bar: 10 µm.

Fig. 2. Photomicrographs of sporulated oocysts of Eimeria caviae, a coccidium species recovered from Guinea pigs Cavia porcellus: (A, B, D) sub-spherical, (C, D) ellipsoidal, and (D, E, F) ovoidal oocysts. In (D) three shapes can be observed in the same field. The arrowheads point the Stieda and parastieda bodies. Sheather’s sugar solution. Scale bar: 10 µm.

Fig. 3. Histograms of (A) length, width and (B) shape-index, and (C) linear regression of the oocysts of Eimeria caviae, a coccidium species recovered from Guinea pigs Cavia porcellus.