Influência da hidrocortisona no desenvolvimento do Schistosoma mansoni em Biomphalaria glabrata

Abstract

The effect of hydrocortisone on the development of BH strain of S. mansoni in B. glabrata snails is evaluated. Snails in a randomly chosen group were submitted to hydrocortisone during four days. In the second day of hydrocortisone exposure, the snails were exposed, each, to ten S. mansoni miracidia. Another group, not treated with hydrocortisone, was exposed to miracidia and observed in the same manner. Various items of data were observed: the infection rate, survival time, prepatent period and total number of cercariae released. It was found that the snails in the group treated with hydrocortisone had a higher infection rate, shorter prepatent periods, produced more cercariae and also had longer survival times. This suggests that the hydrocortisone in snails induces a decrease in resistance to schistosome infection and facilitates the development of the trematode, while also reducing adverse infection effects, thereby leading to longer snail survival.

The influence of hydrocortisone on cellular defence mechanisms of Biomphalaria glabrata

“…These data are in agreement with observation of Serrano et al (2002) who described an increased number of cercariae released by mollusks treated with hydrocortisone.…”

“…Cercarial shedding was not examined in this experiment but, in a previous study (Serrano et al 2002), we observed more cercarial shedding in mollusks treated with hydrocortisone. Thus in snails treated with hydrocortisone, a total of 69,519 cercariaes was obtained, whereas in untreated mollusks, only 2,514 larva were obtained.…”

“…In addition, mollusks treated with hydrocortisone released a greater number of cercariae and the time to the start of larvae elimination was shorter than that observed in untreated snails (Serrano et al 2002). These results, as well as hydrocortisone effect in mammal defence mechanisms, principally in phagocytic cells, led us to examine whether hydrocortisone could exert an immunosuppressive action on the hemocytes of B. glabrata and prevent the hemocyte reaction around trematode larvae, hereby facilitating the development of the parasite.…”

Alterations in the fatty acid profile, antioxidant enzymes and protein pattern of Biomphalaria alexandrina snails exposed to the pesticides diazinon and profenofos

“…Similar observations were noticed by Sharaf El-Din et al 2004using the herbicide dithiopyridine carboxylic acid, by Mahmoud (2006) using the insecticides: regent and mimic, by Abdel Raouf (2007) using the insecticide, by Esmaeil (2009) using the fungicide. However, Serrano et al (2002) reported that Biomphalaria glabrata snails exposed to hydrocortisone had long survival periods than control group.…”

Behavior in Mus musculus of Schistosoma mansoni from mollusks treated with hydrocortisone

“…Two experimental groups consisting of 52 mollusks each were studied: group A comprised infected mollusks not treated with hydrocortisone and group B infected mollusks treated with hydrocortisone 17 . The snails of both groups were infected on the second day of hydrocortisone treatment and in group A by exposing each snail to 10 miracidia of S. mansoni strain BH.…”