Inflammatory response of "pintado" to the infection of Nomimoscolex pertierrae (Eucestoda: Proteocephalidea)

Abstract

An infectious process characterized by piercing lesion promoted by Nomimoscolex pertierrae on the intestine wall of Pseudoplatystoma corruscans (Spix & Agassiz, 1829) was analyzed by histopathology. This pathology was observed during the parasitic fauna study of P. corruscans collected on the high Paraná River floodplain. Samples of 2 cm² size from the infected and uninfected fishes have been submitted to the usual histopathologic procedure, with the samples colored with hematoxylin-eosin and observed under a microscope. Nomimoscolex pertierrae fixes itself on the intestinal epithelium through perforations, resulting on damages to the host`s intestinal epithelium, hemorrhage, lymphocytary infiltration and, on the worst observed case, tissue necrosis. These damages were observed on 2.5% of the collected fishes, and did not present any correlation (p>0.05) between the lesions gravity and the parasite abundance, what may be correlated to an intraspecific variability, which promoted higher parasite virulence.