Alterations in the metabolism of nitrogenous products of Bulimulus tenuissimus (mollusca) in response to experimental infection with larvae of Angiostrongylus cantonensis (nematoda)

Abstract

Mollusks are an essential requirement for the completion of the life cycle by the metaastrogilid nematode Angiostrongylus cantonensis, the causative agent of infections in domestic and wild animals, mainly rodents, and also of neural angiostrongyliasis or eosinophilic meningitis in humans. The terrestrial gastropod Bulimulus tenuissimus is widely distributed in the Brazilian territory and there are other species of the same genus that occur in Brazil and other countries, overlapping with the regions where there are reports on the occurrence of A. cantonensis and angiostrongyliasis. Despite this, the records in the literature about this species as an intermediate host for A. cantonensis are recent. The present study aimed to experimentally infect the mollusk B. tenuissimus, using L1 larvae of A. cantonensis, under laboratory conditions, and to monitor the physiological changes that occurred in the metabolism of nitrogen products. The concentration of total proteins increased in the first week (19.56%), returning to values close to those observed for the control group, which seemed to be related to tissue lysis, since the same pattern of variation was observed for AST and ALT activities. Associated with this, an inversion of the excretory pattern, becoming predominantly uricotelic, was observed in the second week after exposure,  returning to the ureotelic pattern at the end of the pre-patent period. The results reveal that B. tenuissimus is an experimental host that presents a physiological response pattern to infection with A. cantonensis robust, being able to maintain its basic physiological processes, in addition to meeting the demand of the developing parasite.