Influence of exposure Heterorhabditis bacteriophora HP88, (Rhabditida: Heterorhabditidae) on biological and physiological parameters of Pseudosuccinea columella (Basommatophora: Lymnaeidae)

Abstract

Many studies about fasciolosis control have been carried out, whether acting on the adult parasite or in Pseudosuccinea columella, compromising the development of the larval stages. The present study aimed to evaluate, under laboratory conditions, the susceptibility of P. columella to Heterorhabditis bacteriophora HP88, during for 24 and 48 hours of exposure. The snails were evaluated for 21 days for accumulated mortality; number of eggs laid; hatchability rate; biochemical changes; and histopathological analysis. We found that exposure induced a reduction in glucose and glycogen levels, characterizing a negative energy balance, due to the depletion of energy reserves as a result of the direct competition established by the nematode/endosymbiont bacteria complex in such substrates. A mortality rate of 48.25% and 65.52% was observed in the group exposed for 24 h and 48 h, respectively, along with significant impairment of reproductive biology in both exposed groups in relation to the respective controls. The results presented here show that P. columella is susceptible to the nematode H. bacteriophora, with the potential to be used as an alternative bioagent in the control of this mollusk, especially in areas considered endemic for fascioliasis, in line with the position expressed by the World Health Organization Health.

Fasciolosis in ruminants in Brazil

“…The adoption of measures to control snails is essential to reduce cases in endemic areas, and currently the use of chemicals for control in these animals is discouraged due to their low selectivity and long residual period in the environment. Several researchers in Brazil have studied alternative control, using essential oils (Ito et al, 2023;Sperandio et al, 2022), entomopathogenic nematodes (Sperandio et al, 2023;Tunholi et al, 2017;Vidal et al, 2021) and even ducks and geese as a form of physical control (Ximenes et al, 1995).…”