Compatibility of Schistosoma mansoni Cameroon and Biomphalaria pfeifferi Senegal

Parasitology ◽  
2000 ◽  
Vol 121 (5) ◽  
pp. 501-505 ◽  
Author(s):  
V. R. SOUTHGATE ◽  
L. A. TCHUEM TCHUENTÉ ◽  
A. THÉRON ◽  
J. JOURDANE ◽  
A. LY ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Schistosoma Mansoni ◽  
Infection Rate ◽  
Post Infection ◽  
Vectorial Capacity ◽  
Patent Period ◽  
Snail Infection ◽  
Biomphalaria Pfeifferi ◽  
Emergence Pattern ◽  
The Mean

The vectorial capacity of Biomphalaria pfeifferi from Ndiangue, Senegal, was investigated with an allopatric isolate of Schistosoma mansoni from Nkolbisson, Cameroon. The snail infection rate after exposure to a single miracidium per snail (MD1) was 56·3%, and 91·6% for snails exposed to 5 miracidia per snail (MD5). The minimum pre-patent period was 21 days. The mean total cercarial production for the MD1 group was 18511 cercariae per snail, and 9757 cercariae for the MD5 group. The maximum production of cercariae for 1 day was 4892 observed in a snail from the MD1 group at day 43 post-infection. The mean longevity of snails was higher in group MD1 (88 days p.i.) than in group MD5 (65 days p.i.). The chronobiological emergence pattern revealed a circadian rhythm with one shedding peak at mid-day. Comparisons are made with the vectorial capacity of the sympatric combination of B. pfeifferi Senegal/S. mansoni Senegal.

scholarly journals Die invloed van blootstelling aan mirasidiums Schistosoma mansoni op mortaliteitskoerse van kohorte van vier geografiese stamme van Biomphalaria pfeifferi

1995 ◽  
Vol 14 (1) ◽  
pp. 12-16
Author(s):  
K. N. De Kock
Keyword(s):  
Life Expectancy ◽  
Schistosoma Mansoni ◽  
First Generation ◽  
Mortality Rates ◽  
Biomphalaria Pfeifferi ◽  
Generation Cohorts ◽  
The Mean ◽  
Per Capita

First generation cohorts of 25 specimens each of parental populations of Biomphalaria pfeifferi from four different localities, were each exposed to three Schistosoma mansoni miracidia per snail at an age of four weeks. The effect on survival was evaluated by calculating the weekly per capita mortality rates and the mean life-expectancy of the exposed snails. No significant differences could be demonstrated between the per capita mortality rates of F₁ cohorts of the two parental strains originating from localities in endemic bilharzia areas. Likewise there were no significant differences in this respect as far as F₁ cohorts of the two strains originating from localities in non-endemic bilharzia areas were concerned.

scholarly journals Susceptibility of Biomphalaria glabrata submitted to concomitant infection with Angiostrongylus costaricensis and Schistosoma mansoni

2016 ◽  
Vol 77 (3) ◽  
pp. 451-458 ◽  
Author(s):  
L. R. Guerino ◽  
J. F. Carvalho ◽  
L. A. Magalhães ◽  
E. M. Zanotti-Magalhães
Keyword(s):  
Schistosoma Mansoni ◽  
Infection Rate ◽  
Biomphalaria Glabrata ◽  
Prior Exposure ◽  
Intermediate Hosts ◽  
Patent Period ◽  
Concomitant Infection ◽  
Freshwater Molluscs

Abstract The easy adaptation of Angiostrongylus costaricensis, nematode responsible for abdominal angiostrongyliasis to several species of terrestrial and freshwater molluscs and the differences observed in the interactions of trematodes with their intermediate hosts have induced us to study the concomitant infection of Biomphalaria glabrata with Schistosoma mansoni and A. costaricensis. Prior exposure of B. glabrata to A. costaricensis (with an interval of 48 hours), favored the development of S. mansoni, observing higher infection rate, increased release of cercariae and increased survival of molluscs, when compared to molluscs exposed only to S. mansoni. Prior exposure of B. glabrata to A. costaricensis and then to S. mansoni also enabled the development of A. costaricensis since in the ninth week of infection, higher amount of A. costaricensis L3 larvae was recovered (12 larvae / mollusc) while for molluscs exposed only to A. costaricensis, the number of larvae recovered was lower (8 larvae / mollusc). However, pre-exposure of B. glabrata to S. mansoni (with an interval of 24 hours), and subsequently exposure to A. costaricensis proved to be very harmful to B. glabrata, causing extensive mortality of molluscs, reduced pre-patent period to release cercariae and greater recovery of L3 A. costaricensis larvae.

scholarly journals Experimental infection of dogs with Echinococcus granulosus (Batsch, 1986) from protoscoleces of donkey's hydatid cyst

2004 ◽  
Vol 28 (1) ◽  
pp. 15-21
Author(s):  
Raad Harbi Rahif ◽  
Amal Hassan Atae
Keyword(s):  
Small Intestine ◽  
Hydatid Cyst ◽  
Dose Rate ◽  
Echinococcus Granulosus ◽  
Infection Rate ◽  
Experimental Infection ◽  
Post Infection ◽  
Gravid Proglottid ◽  
Total Length ◽  
The Mean

This study was conducted, for the 1st time in Iraq, to infect 5 puppies, 1 - 5 month old, with protoscoleces of hydatid cyst isolated from the liver of donkey, slaughtered at zoo abattoir of Al-Zawra park in Baghdad, at a dose rate of 10000 protoscoieces i puppy (n=2) and 20000 protoscoleces / puppy (n=3) for 35 and 40 days post infection. The dogs were killed and the developed Echinococcus granulosus were isolated from the small intestine. Results of the study revealed  variation in the period of maturation of the collected cestodes, and the mean total length of the mature worms at 35 days PI was 4.53+ 0.24 mm, and for those at 40 days PI was 7+ 0.20 mm, whereas for the gravid ones at the same age of the latter was 8.57 + 0.25 mm. Results found that infection rate with E. granulosus, which their strobilae composed from 4 proglottids at 35 days PI, was 29.03%, and with those, which their strobilae composed from 5 proglottids at 40 days PI, the rate was 0.76%. It was found that the mean length of the gravid proglottid equal to or longer than half the total worm length with a ratio of 1.77 + 0.05 for those at 35 days of age, and 2.2 + 0.35 and 1.93 + 0.01 for mature and gravid cestodes at the age of 40 days.

Attenuation of Schistosoma mansoni cercariae with a molluscicide derived from Millettia thonningii

Parasitology ◽  
1994 ◽  
Vol 109 (5) ◽  
pp. 559-563 ◽  
Author(s):  
S. Perrett ◽  
P. J. Whitfield ◽  
A. Bartlett ◽  
L. Sanderson
Keyword(s):  
Schistosoma Mansoni ◽  
Post Infection ◽  
Secondary Compounds ◽  
Chloroform Extract ◽  
West African ◽  
Elisa Assay ◽  
Plant Secondary Compounds ◽  
The Mean ◽  
Pre Treatment ◽  
Antibody Levels

A chloroform extract of molluscicidal plant secondary compounds from the seeds of a West African legume Millettia thonningii was used to attenuate cercariae of Schistosoma mansoni prior to infection of NMRI female mice. Exposure of cercariae to 0·3, 0·6, 1·3, 2·5, 10 or 20 mg/l concentrations of extract for 30 mm, immediately before standardized infection, was associated with a concentration-dependent decline in worm establishment at 55 days post-infection. The mean numbers of adult worms established declined from about 17 worms/mouse with control cercariae and those exposed to 0·3 mg/l Millettia to 0·1 worms/mouse after 10 mg/l pre-treatment. Mice exposed to cercariae after 20 mg/l pre-treatment had no adult worms at 55 days post-infection. The activities of cercariae 30 mm after exposure to Millettia extract at concentrations up to 2·5 mg/l were similar to those of control larvae: none was immobile. Exposure to higher concentrations of Millettia progressively reduced swimming activity and increased the proportion of immobile cercariae. After pretreatment with 20 mg/l Millettia the majority of larvae were immobile. Levels of anti-parasite antibodies (estimated by ELISA assay using an adult worm-based antigen preparation) rose between 21 and 55 days p.i. with control cercariae and those pre-treated with 2·5 mg/l Millettia. After 5 mg/l pre-treatment, cercariae induced a reduced antibody rise, while mice exposed to cercariae after 10 mg/l pre-treatment showed no rise in anti-parasite antibody levels. These results are discussed in the context of protocols which could possibly use Millettia-attenuated cercariae to induce useful levels of protection in mice towards further cercarial challenge.

Energy constraint exerted by the parasite Schistosoma mansoni on the locomotion of its snail host, Biomphalaria glabrata

1996 ◽  
Vol 74 (4) ◽  
pp. 594-598 ◽  
Author(s):  
Claudia Gérard
Keyword(s):  
Resource Allocation ◽  
Schistosoma Mansoni ◽  
Biomphalaria Glabrata ◽  
Snail Host ◽  
Locomotory Activity ◽  
Patent Period ◽  
Energy Constraint

The consequences of the constraint caused by the parasite Schistosoma mansoni on the locomotory activity of its snail host, Biomphalaria glabrata, were studied during the patent period. Rates of locomotion were determined 6 times per 24-h period for juvenile and adult snails with single-miracidium infections, then compared with those of healthy snails of the same age. The locomotory activity of infected snails was the same during the day and at night, whereas control snails moved less at night than during the day. The locomotion of snails infected when immature was similar to that of the controls during the day and superior at night. The locomotion of snails infected when mature decreased regularly during patency and clearly decreased in comparison with that of healthy snails. The results are interpreted in terms of energy constraint on the mode of resource allocation of the host due to the parasite.

scholarly journals Biological implications of the phenotypic plasticity in the Schistosoma mansoni - Nectomys squamipes model

2008 ◽  
Vol 50 (4) ◽  
pp. 229-232 ◽  
Author(s):  
Elaine Machado Martinez ◽  
Michele Costa-Silva ◽  
Renata Heisler Neves ◽  
Regina Maria Figueiredo de Oliveira ◽  
José Roberto Machado-Silva
Keyword(s):  
Phenotypic Plasticity ◽  
Schistosoma Mansoni ◽  
Biological Behavior ◽  
Egg Viability ◽  
Patent Period ◽  
Water Contact ◽  
Schistosomiasis Mansoni ◽  
Infectivity Rate ◽  
Biological Modification

The water-rat Nectomys squamipes is mostly important non-human host in schistosomiasis mansoni transmission in Brazil, due to its susceptibility, high abundance and water-contact pattern. During experimental infection of N. squamipes with Schistosoma mansoni, adult worms show phenotypic plasticity. This finding led us to investigate whether biological behavior is also affected. This was assessed comparing the biological characteristics of four S. mansoni strains: BE (State of Belém do Pará), CE (State of Pernambuco), CMO (State of Rio Grande do Norte) and SJ (State of São Paulo) using laboratory-bred N. squamipes. The infection was monitored by determination of the pre-patent period, fecal egg output, egg viability, intestinal egg count and, infectivity rate. No biological modification was observed in these parameters. Overall results highlight that N. squamipes was susceptible to several S. mansoni strains, suggesting that it might contribute to the maintenance of schistosomiasis mansoni in Brazil.

scholarly journals QUANTIFICATION OF THE POPULATION AND PHAGOCYTARY ACTIVITY OF HEMOCYTES OF RESISTANT AND SUSCEPTIBLE STRAINS OF Biomphalaria glabrata AND Biomphalaria tenagophila INFECTED WITH Schistosoma mansoni

1997 ◽  
Vol 39 (4) ◽  
pp. 197-202 ◽  
Author(s):  
F. S. de M. BEZERRA ◽  
J. A. NOGUEIRA-MACHADO ◽  
M. M. CHAVES ◽  
R. L. MARTINS ◽  
P. M. Z. COELHO
Keyword(s):  
Schistosoma Mansoni ◽  
Cell Population ◽  
Metabolic Activity ◽  
Post Infection ◽  
Biomphalaria Glabrata ◽  
Determinant Factors ◽  
Circulating Cells ◽  
Resistant Strains ◽  
First Time

Among the determinant factors in the resistance and susceptibility of Biomphalaria to Schistosoma mansoni, hemocytes play an important role. Aiming at studying S. mansoni/Biomphalaria interactions related to hemocytes, the first step is certainly connected with the standardization of this cell population in uninfected Biomphalaria. In this way, quantification of this cell population in hemolymph, as well as its phagocitary capacity, have been determined for the first time. Furthermore, using susceptible and resistant strains of B. glabrata and B. tenagophila, the hemocytegram and phagocytary capacity of hemocytes after infection with S. mansoni were determined too. Resistant and susceptible strains of B.glabrata (BA and BH, respectively), as well as resistant and susceptible strains of B. tenagophila (Taim and CF, respectively) were infected with 10 miracidia of the LE and SJ strains of S. mansoni, respectively. These infected snails and respective uninfected controls were assessed in relation to the number of circulating hemocytes and alteration in the phagocytary capacity, by using Zymozan and MTT. Reading was taken by means of a spectrophotometer at 5 hours and 1,2,5,10,20 and 30 days after infection. The results showed a decrease in population of the circulating phagocytary cells, 5 hours after infection. One day post-infection, the circulating cells of the susceptible snails showed an increased metabolic activity, but the same event could not be observed in the resistant strains. In the subsequent observation periods, significant differences among the strains studied could not be observed until the end of the experiment

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