The effect of sublethal concentrations of the molluscicide niclosamide on the infectivity ofSchistosoma mansonicercariae

1975 ◽  
Vol 49 (4) ◽  
pp. 245-250 ◽  
Author(s):  
A. M. Ghandour
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Mammalian Host ◽  
Mesenteric Veins ◽  
Worm Recovery ◽  
Consequent Reduction ◽  
Sublethal Concentrations

ABSTRACTExperiments were conducted to assess the effect of sublethal concentrations of niclosamide on the infectivity ofSchistosoma mansonicercariae. Exposure of cercariae to 0.02 mg/1 and 0.05 mg/1 of niclosamide, respectively, for only two hours increased their mortality during penetration of mammalian host skin. The observed increase in mortality in the skin resulted in a consequent reduction of adult worm recovery from the liver and mesenteric veins of animals infected with the treated cercariae.

A study of the relationship between temperature and the infectivity of Schistosoma mansoni and Schistosoma haematobium cercariae

1976 ◽  
Vol 50 (3) ◽  
pp. 193-196 ◽  
Author(s):  
A. M. Ghandour
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
High Temperatures ◽  
Schistosoma Haematobium ◽  
Mammalian Host ◽  
Worm Recovery ◽  
The Relationship

AbstractIt was shown that maintenance of cercariae of S. mansoni and S. haematobium at low (10°C) and high temperatures (40°C) markedly increased their mortality during penetration of mammalian host skin. These increased losses in the skin accounted for the known decrease in infectivity, as measured by adult worm recovery, of cercariae kept at low or high temperatures.

scholarly journals Immunopathology of Schistosoma mansoni infection in rabbits: (A preliminary report)

1982 ◽  
Vol 77 (2) ◽  
pp. 165-171
Author(s):  
Nelia S. Tan-Liu ◽  
Moyses Sadigursky ◽  
Zilton A. Andrade
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Preliminary Report ◽  
Egg Production ◽  
Natural Antibodies ◽  
Eosinophilic Infiltration ◽  
Pathological Changes ◽  
Worm Recovery ◽  
Granulomatous Formation ◽  
Marked Resistance

Five rabbits infected with Schistosoma mansoni showed marked resistance, which resulted in low worm recovery and low egg production. Pathological changes appeared in liver and intestines as scattered foci of eosinophilic infiltration around immature eggs, with only occasional granulomatous formation. Antibodies to ovular and adult worm structures were demonstrated by immunofluorescence in the sera of rabbits prior to infection (natural antibodies) and specially following infection by S. mansoni. These findings point out to the peculiarities of the immunopathology of schistosomiasis in rabbits.

scholarly journals Kinectics of the pulmonary phase of Schistosoma mansoni in mice treated with dexamethasone

1990 ◽  
Vol 32 (3) ◽  
pp. 168-171 ◽  
Author(s):  
Marco Victor Hermeto ◽  
Rosilene Siray Bicalho ◽  
Alan Lane de Melo ◽  
Leógenes Horácio Pereira
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Worm Burden ◽  
Early Death ◽  
Portal System ◽  
The Third ◽  
Schistosomiasis Mansoni ◽  
Worm Recovery

In the experimental schistosomiasis mansoni glucocorticoids cause a reduction in the worm burden when administered in the week of infection or, the longest, at the next week. In order to determinate the probable(s) site(s) of reduction of the worm burden, mice were infected with cercariae of LE strain of S. mansoni and dexamethasone was administered daily (50 mg/kg, subcutaneously) starting 1 hour before infection until the eighth day. Mice were sacrificed daily starting on the third day after infection until the ninth day, and schistosomula from lungs were collected. Six weeks after infection, the remaining mice were sacrificed and perfused for adult worm recovery. Analysis of the results showed that the non-treated mice presented larger numbers of lung larvae than the treated ones, and this difference was also found later in the worm burden in the portal system. This difference may reflect the early death of larvae in treated animals, before or after reaching the lungs.

Effects of praziquantel and oxamniquine on a Saudi Arabian strain of Schistosoma mansoni in mice

1990 ◽  
Vol 64 (1) ◽  
pp. 62-64 ◽  
Author(s):  
A. M. Ghandour ◽  
A. A. Banaja ◽  
I. M. Shalaby
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Marked Reduction ◽  
Saudi Arabian ◽  
Low Doses ◽  
Worm Recovery

ABSTRACTThe prophylactic and curative effects of praziquantel and oxamniquine on a Saudi Arabian strain of Schistosoma mansoni in MF-1 mice were assessed. The drugs were administered orally. At 240 mg/kg praziquantel, there was a reduction of 89·1% in adult worm recovery and a marked reduction in tissue deposited eggs. The reduction in adult worm recovery after dosing with 50 mg/kg oxamniquine was 89·2%. At low doses (40 mg/kg praziquantel and 30 mg/kg oxamniquine) administered at 11 days, 5 days and 3 h before and 5, 21 and 49 days after infection, the reduction in adult worm recovery was 0·0%, 65·1%, 58·8%, 33·6%, 0·0% and 76·0% for praziquantel and 0·0%, 66·0%, 60·0%, 41·3%, 10·8% and 79·0% for oxamniquine. Numbers of lung schistosomula and the size of hepatic granulomata were also reduced.

scholarly journals Multiomic analysis of Schistosoma mansoni reveals unique expression profiles in cercarial heads and tails

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
James R. Hagerty ◽  
Hyung Chul Kim ◽  
Emmitt R. Jolly
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Expression Profiles ◽  
Snail Host ◽  
Differentially Expressed ◽  
Mammalian Host ◽  
Weak Correlation ◽  
Translational Activity ◽  
Host Invasion

AbstractSchistosomes require both molluscan and mammalian hosts for development. The larval cercaria exits the snail host and swims to identify and invade the mammalian host. The cercaria has two macrostructures, the head and the tail. The head invades the host, where it matures into an adult worm. The tail is lost after host invasion. Translation in the cercaria differs in each macrostructure, with higher levels of translation in the cercarial tail and little to no translational activity in the cercarial head. We compared the transcriptome and proteome of the cercarial head and tail and observed stark differences between the two macrostructures. We identified unique and differentially expressed transcripts and proteins, including ribosomal components expressed in higher levels in tails than in heads, which may explain the differences in translation levels between heads and tails. We also characterized the weak correlation between transcription and translation in infectious cercarial heads and tails.

Immunoprecipitins in human schistosomiasis detected with adult worm antigens released by 3M KC1

1977 ◽  
Vol 51 (1) ◽  
pp. 71-72 ◽  
Author(s):  
Mauro Scapin ◽  
Miriam Tendler
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Calcium Chloride ◽  
Surface Proteins ◽  
Immunochemical Characterization ◽  
Human Schistosomiasis

Several methods are being applied for solubilizing adult Schistosoma mansoni antigens which may allow their immunochemical characterization and purification. Studies on antigens and immunoprecipitins in schistosome infections have been carried out with homogenized extracts of adult worms and/or larval forms of Schistosoma mansoni in saline (Biguet et al., 1962; Kagan and Norman, 1963; Silva and Ferri, 1965), or water (Kent, 1963). Kusel (1972) studied surface proteins in S. mansoni membrane, treating the worms with 0·5% saponin in 3% calcium chloride. Murrel et al. (1974) compared by immunodiffusion a crude culture antigen with extracts obtained by freeze-thawing of adult worms and by treatment in 3M KCl.

Experimental Schistosoma bovis infection in goats. Circulating antigen and antibody responses to egg and adult worm antigens during infection and following treatment with praziquantel

Parasitology ◽  
1996 ◽  
Vol 113 (4) ◽  
pp. 367-375 ◽  
Author(s):  
M. V. Johansen ◽  
Y. Fillié ◽  
J. Monrad ◽  
N. Ø. Christensen ◽  
A. Deelder
Keyword(s):  
Adult Worm ◽  
Specific Antibody ◽  
Post Treatment ◽  
Antibody Responses ◽  
Antibody Detection ◽  
Faecal Samples ◽  
Schistosoma Bovis ◽  
Worm Recovery ◽  
Circulating Antigen ◽  
Positive Correlations

SUMMARYCirculating antigen levels and antibody responses in Schistosoma bovis-infected West African Dwarf goats were evaluated during infection and following treatment with praziquantel (60 mg/kg) 13 weeks post-infection. One day, 1 week and 4 weeks post-treatment, subgroups of goats were sacrificed and perfused for worm recovery. For comparison, parasite-free control animals were included. Blood and faecal samples were collected biweekly. Two gut-associated schistosome antigens, circulating cathodic and circulating anodic antigen (CCA and CAA) and 3 specific antibody responses (total Ig, IgG and IgM) were measured. For specific antibody detection, crude S. bovis adult worm and egg homogenates were used. The level of CCA in the infected groups was significantly elevated from the time of onset of egg excretion onwards. However, following treatment, the CCA litres dropped to control levels within 1 week post-treatment. Strong positive correlations were found between CCA levels and worm counts and faecal egg counts during peak egg excretion. The correlations of CAA and specific antibody litres to egg and worm counts were poor. The antibody responses were all significantly elevated in the infected goats during patency, but only marginally affected by the treatment. Hence, CCA proved to be superior by correlating strongly to the level of infection and by being a sensitive indicator of the effect of treatment.

The relationship between the age of Schistosoma mansoni cercariae and their ability to penetrate and infect the mammalian host

Parasitology ◽  
1983 ◽  
Vol 87 (3) ◽  
pp. 481-492 ◽  
Author(s):  
J. Ruth Lawson ◽  
R. A. Wilson
Keyword(s):  
Schistosoma Mansoni ◽  
Stratum Corneum ◽  
Mass Mortality ◽  
Mammalian Host ◽  
Energy Reserves ◽  
Age Related ◽  
Abdominal Route ◽  
Relationship Of ◽  
The Relationship ◽  
Related Mortality

SummaryThe ability of the cercariae of Schistosoma mansoni to penetrate the tails of mice was shown to remain constant throughout their lives. However, their capacity to establish themselves and then reach maturity decreased as they aged. The abdominal route of penetration produced consistently higher maturation rates than the tail route. Significantly different maturation rates were obtained by modifying the standard tail infection technique. Evidence is presented that age-related mortality of schisto-somula occurs within 24 h of penetration and may be associated with the exhaustion of energy reserves during the penetration of the stratum corneum. The relationship of this age-related mortality to ‘mass mortality’ is discussed.

scholarly journals In vitro effects of artesunate on the survival of worm pairs and egg production of Schistosoma mansoni

2009 ◽  
Vol 83 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Y. Mitsui ◽  
M. Miura ◽  
Y. Aoki
Keyword(s):  
Schistosoma Mansoni ◽  
Adult Worm ◽  
Survival Time ◽  
Egg Production ◽  
Inhibitory Effect ◽  
Male And Female ◽  
Paired Male ◽  
In Vitro Effects ◽  
Paired Female

AbstractThe effect of artesunate (ART) on the survival time of adult worm pairs of Schistosoma mansoni and on their egg output during in vitro culture was assessed. ART significantly decreased the survival time of both paired male and female worms at concentrations of 5, 10, 20 and 40 mg l− 1 during in vitro cultivation. An inhibitory effect of ART on the daily egg output of paired female worms during in vitro cultivation was also observed.

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