Caracterização morfométrica e morfológica por microscopia de campo claro, microscopia de varredura a laser confocal e microscopia eletrônica de varredura de Eurytrema coelomaticum (Giard & Billet, 1892) Looss, 1907 (Trematoda: Digenea) recuperado de bovinos no Estado do Rio de Janeiro, Brasil

Abstract

The eurytrematosis is a helminthiasis of ruminants whose etiological agents are Eurytrema coelomaticum and Eurytrema pancreaticum that lodge mainly in the parcreas and may cause changes that trigger pancreatitis and cachexia. E. coelomaticum is the prevalent species in Brazil, but there is a lack of morphological information about the adult flukes. The objective of this work was perform a characterization of E. coelomaticum slaughtered from cattle from the Santa Cruz and Barra Mansa County in the State of Rio de Janeiro and compare with specimens deposited in the Helminthological Collection of the Instituto Oswaldo Cruz (CHIOC). The specimens were stained with hydrochloric carmine, mounted on slide glass on slides with Canada balsam, analyzed by brightfield microscopy and confocal scanning laser. Some specimens were mounted in paraffin and processed according to routine histological technique for histological analysis. The other specimens were processed and gold coated 20-25nm for viewing on a scanning electron microscope. The morphometric analysis of 50 specimens showed the following values (the measures are given in millimeters), vitelline glands measured 0.67 to 2.14 (1.30 ± 0.44) in length and 0.33 to 0.93 ( 0.58 ± 0.15) width; distance between the anterior region of the body and ventral sucker 1.38 to 2.8 (2.13 ± 0.44); distance between ventral sucker and the posterior region of the body 1.98 to 5.35 (3.65 ± 1.06); distance between the cecum and posterior region of the body 0.5 to 1.69 (1.09 ± 0.35). Through the morphological analysis by brightfield microscopy proved that Mehlis' glands, ootype, yolk reservoir and yolk duct are present. The morphological analysis by confocal microscopy, first performed for helminth observation of this specie, allowed a more detailed view of the structures that constitute the cirrus pouch showing the seminal vesicle coiled and storing sperm, presence of ejaculatory duct and prostate glands; ovary with oocytes; Laurer's channel; testicles with sperm; muscles of the body, suckers and pharynx dense. The scanning electron microscopy confirmed the absence of structures in the tegument is flattened with small lumps cubic shaped; oral sucker, ventral sucker and flat cirrus also and tegument with fold. It could be concluded that the morphometric and morphological data of the present study are consistent with those described in the literature. New measures of vitelline glands; ratio of body length to the width of the body; distances between: anterior region of body and ventral sucker; ventral sucker and the posterior region of the body; cecum and posterior region of the body, analyzed in this study, as well as the order of muscle bundles of the seed coat, suckers and pharynx; the cirrus pouch structures, ovary and testicles, visualized by confocal microscopy, and to confirm the absence of structures in the inner layer of the tegument and cirrus, observed by scanning electron microscopy contribute to the description and study of the species.