Cercariae of the bird schistosome Trichobilharzia regenti and of the human schistosome Schistosoma mansoni employ proteases to invade the skin of their definitive hosts. To investigate whether a similar proteolytic mechanism is used by both species, cercarial extracts of T. regenti and S. mansoni were biochemically characterized, with the primary focus on cysteine peptidases. A similar pattern ...

Lymnaeids in nature are subjected to temperature fluctuations that may have an influence on the shedding of cercariae. Thus, experimental infections of Lymnaea truncatula by Paramphistomum daubneyi were performed to determine whether a sudden fall in temperature--daily dipping of infected snails into spring water at 14-15 degrees C, or at 6-8 degrees C--followed by its increase at 20 degrees C ...

Biotinylation is proposed for the identification of surface proteins in Schistosoma mansoni using the streptavidin-HRP conjugate for the detection of labeled polypeptides. However, control samples also showed several endogenous biotinylated polypeptides. In an attempt to determine the possibility of nonspecific binding between the streptavidin-HRP conjugate and polypeptides from S. mansoni, the...

As abrupt changes in water temperature (thermal shock) triggered a significantly greater cercarial emergence of Fasciola hepatica from experimentally infected Galba truncatula, laboratory investigations were carried out to study the influence of light on cercarial emergence in snails subjected to a thermal shock every week (a mean of 12 °C for 3 h) during the patent period. Thermal shock for th...

The parasitic helminth Schistosoma mansoni is a major public health concern in many developing countries. Glycoconjugates, and in particular the carbohydrate component of these products, represent the main immunogenic challenge to the host and could therefore represent one of the crucial determinants for successful parasite establishment. Here we report a comparative glycomics analysis of the N...

Human complement activation by cercariae and schistosomula of the human parasite Schistosoma mansoni was studied in vitro. Cercariae are composed of tails which are shed after infection of the host and bodies which transform into the larvae or schistosomula after infection. After incubation in fresh normal human serum (NHS), cercarial tails bound more anti-C3 antibodies than did cercarial bodie...

Studies involving comparisons of taxa that vary in their degree of relatedness may allow the distinction of functional and phylogenetic components in cercarial sensory systems. In this study, cercariae of allocreadiids Bunodera Railliet, 1896 and Crepidostomum Braun, 1900, lecithodendriid Allassogonoporus Olivier, 1938 and opecoelid Allopodocotyle Pritchard, 1966 were compared as regards ultras...

Experimental infections of two South American lymnaeids (Lymnaea neotropica and L. viatrix var. ventricosa) with Paramphistomum daubneyi were carried out to determine if these snail species could sustain larval development of this digenean and, if so, to specify their potential for cercarial production. A French population of Galba truncatula infected and raised according to the same protocol s...

BACKGROUND Skin invasion is the initial step in infection of the human host by schistosome blood flukes. Schistosome larvae have the remarkable ability to overcome the physical and biochemical barriers present in skin in the absence of any mechanical trauma. While a serine peptidase with activity against insoluble elastin appears to be essential for this process in one species of schistosomes, ...

Schistosomiasis (bilharzia) is a tropical disease caused by trematode parasites (Schistosoma) that affects hundreds of millions of people in the developing world. Currently only a single drug (praziquantel) is available to treat this disease, highlighting the importance of developing new techniques to study Schistosoma. While molecular advances, including RNA interference and the availability o...