Histopathology from liver of tuvira ( Gymnotus spp.) parasitized by larvae of nematodes

Abstract

The aim of this study was to evaluate the histological changes in the liver of thirty-five

Morphological and morphometric features of nematode-cysts in Gymnotus inaequilabiatus liver in the Brazilian Pantanal

“…In the present study, 11.2% of the livers assessed showed a higher prevalence of Brevimulticaecum sp., in accordance with what was found by Vieira et al (2010), but less with Ventura et al (2016). However, liver infection by nematodes in Gymnotus spp.…”

“…The largest cysts harbor a thicker collagen-layer, which might indicate a chronic reaction in older larvae with higher deposition time. These findings suggest that the vascular via was not used by these nematodes in G. inaequilabiatus, since vascular alterations such as perivascular inflammatory reaction, coagulative necrosis, and edematous areas, as well as obstructive thrombosis, were not observed, in contrast to other studies (SZÉKELY et al, 1996;VENTURA et al, 2016). Based on the amount of cyst structures found after the macroscopic and microscopic assessment, we inferred that this organ is a critical site of nematode infection.…”

Liver of the fish Gymnotus inaequilabiatus and nematode larvae infection: Histochemical features and expression of proliferative cell nuclear antigen

“…Its presence in MAs is associated with iron recycling, starvation and pathology (Agius, , ; Agius & Roberts, ; Wolke, ). Haemosiderin has also been described in hepatocytes in association with many pathological conditions (Batts, ; Iancu, ; Iancu et al., ) and was mentioned in the same host–parasite system of current study (Ventura et al., ). Pathological iron overload is a well known aspect during chronic inflammation as an adaptive strategy to deplete bacteria from essential iron, regardless whether the inflammation is due to bacterial infection.…”

“…Some studies on parasites of the tuvira from the Pantanal Region have shown third‐larval stage of the nematode Brevimulticaecum sp. was frequently encountered in most organs of G. inaequilabiatus (Dezfuli, Fernandes, et al., ; Isaac, Guidelli, Franca, & Pavanelli, ; Ventura et al., ; Vieira et al., ). Tuvira acts as paratenic host for Brevimulticaecum sp., and the adult individuals of this worm were found in the intestine of Pantanal caiman, Caiman yacare (Catto & Amato, ; Farias et al., ).…”

“…Moreover, liver histopathology in fish has increasingly been incorporated into programmes monitoring biological effects of environmental contaminants (Feist, Stentiford, Kent, Ribeiro Santos, & Lorance, ). Fish response to extraintestinal worms in the formation of connectival capsule or granulomas on the outer surface of the digestive tract (Dezfuli, Pironi, Shinn, Manera, & Giari, ; Dezfuli, Pironi, Simoni, Shinn, & Giari, ), on or in heart tissue (Dezfuli et al., ), in skeletal muscle (de Buron & Roumillat, ; Dezfuli, Manera, Lorenzoni, et al., ; Umberger, de Buron, Roumillat, & McElroy, ) and within the viscera for numerous helminths genera is well described (Dezfuli, Fernandes, et al., ; Horbowy et al., ; Mehrdana et al., ; Ventura et al., ). Granulomas are focal chronic inflammatory lesions that appear as nodules in tissues and organs of the host (Dezfuli, Fernandes, et al., ; Dezfuli, Manera, et al., ; Ferguson, ).…”