ABSTRACT
Schistosomiasis a prevalent parasitic disease in tropical and sub-tropical areas, which comes in the second place in terms of socioeconomic and public health burden. Around 600 million people in 74 countries are infected yearly, predominantly in the developing world. The aim of this work was to assess the efficiency of three extracts from Carica papaya (methanol, ethanol and butanol extracts) for their molluscicidal and anti-schistosomal activities. The LC50of methanol, ethanol and butanol extracts of Carica papaya against B. alexandrinea were 180, 499.3 and 509.1 mg/L while the respective LC90values were 220.3, 700.6, 769.6 mg/L respectively. The effect of these extracts on Biomphalaria alexandrina snails and larval stages of Schistosma mansoni, for miracidia the LC50of methanol, ethanol and butanol extracts ofCaricapapaya against miracidia were 3.4, 15.4and 8.1 mg/L, respectively, while the respective LC90values were 8.4, 38.2, 11.2 mg/L, and for cercariae the LC50of methanol, ethanol and butanol extracts ofCaricapapaya were 2, 20and 4mg/L, while the respective LC90values were 13.5, 80.5, 18.5mg/L respectively was evaluated, in addition to flowcytometric analysis of CD4, CD25, FOXP3 and TGF-βlevels during S. mansoniinfection in mice. The in-vivo results showed that the three extracts have variable potential against snails and miracidia and cercariae ofS. mansoni. The mortality rate in B. alexandrinasnails for methanol, ethanol and butanol extracts ofCarcia papaywere 86%, 45% and 64%, respectively. While it was 83%, 35% and 66%, respectively in miracidia and 92%, 40% and 70%, respectively in cercariae. The results indicated that methanol extract from Carica papaya recorded higher activity against snails, miracidia and cercariae. The levels of CD4, CD25, FOXP3 regulatory T (Treg) cells were decreased significantly (p<0.001) in infected mice compared to healthy controls. However, there was a significant (p<0.001) increase in levels of TGF-β. A significant increase in the levels of CD4, CD25, and FOXP3 Treg in Carica papaya treated group compared to infected control group, with a significant (p<0.001) decrease in TGF-βlevel than infected group. In conclusion, methanol extract was more effective at concentration of LC50 180 and LC90 220.3than ethanol and butanol extracts ofCaricapapaya therefore controlling B. alexandrinasnails by methanol extract is a promising way as it is an eco-friendly strategy in rural areas of developing countries, where schistosomiasis is endemic. Moreover, the increased immune defense mechanism in treated group with the same extracts is a promising target for new immune modulatory strategies against schistosomiasis
ABSTRACT
Abstract:Schistosomiasis remains a disease of major global public health concern since it is a chronic and debilitating illness. The widely distributed Schistosoma mansoni that causes intestinal schistosomiasis represents a great threat. Its world-wide distribution is permitted by the broad geographic range of the susceptible species of its intermediate host, Biomphalaria, which serves as an obligatory host for the larval stage, at which humans get infected. The objectives were to identify the proteins responsible for the snails' compatibility outcome through differentiation between the total proteins among Biomphalaria alexandrina snails at different ages. The work was conducted on snails that differ in age and genetic backgrounds. Four subgroups (F1) from the progeny of self-reproduced susceptible and resistant snails (F0) were studied. Infection rates of these subgroups (young susceptible, adult susceptible, young resistant and adult resistant) were 90 %, 75 %, 40 % and 0 %, respectively. Using Sodium Dodecyl Sulphate Polyacrylamide Gel electrophoresis (SDS-PAGE), differences in protein expression were evaluated between adult and young snails of different subgroups. Dice similarity coefficient was calculated to determine the percentage of band sharing among the experimental subgroups. The results showed that the combination of similarities between age and compatibility status of the snails, lead to the highest similarity coefficient, followed by the combination of similarities of both genetic origin and age, even though they differ in the compatibility status. On the other hand, the differences in the genetic background, age and compatibility status, lead to the least similarity index. It was also found that the genetic background in young snails plays a major role in the determination of their compatibility, while the internal defense system has the upper hand in determining the level of adult compatibility. In conclusion, the findings of the present work highlight the great impact of the snail age in concomitance with the genetics and the internal defense in the determination of B. alexandrina/S.mansoni compatibility. Future works are recommended, as further characterization of the shared protein bands among the studied subgroups is needed to clarify their role in host-parasite relationship. Rev. Biol. Trop. 64 (4): 1747-1757. Epub 2016 December 01.
Resumen:La esquistosomiasis es una enfermedad crónica y debilitante que constituye una problemática de salud pública a nivel mundial. Debido a que Schistosoma mansoni está ampliamente distribuida y a que es el causante de la esquistosomiasis intestinal representa una gran amenaza. Biomphalaria es el hospedero intermedio y obligatorio para el estado larval, presenta una amplia distribución geográfica e infecta al ser humano. El objetivo fue identificar las proteínas responsables del efecto de compatibilidad en caracoles Biomphalaria alexandrina de distintos estadios a través de la diferenciación del total de proteínas en ellos. La investigación se llevó a cabo con caracoles de diferentes edades y antecedentes genéticos. Se estudiaron cuatro subgrupos (F1) de la progenie de caracoles susceptibles y resistentes reproducidos asexualmente (F0). Las tasas de infección de estos subgrupos (juvenil susceptible, adulto susceptible, juvenil resistente, adulto resistente) fueron 90 %, 75 %, 40 % y 0 %, respectivamente. Con la electroforesis en gel de poliacrilamida en presencia de dodecilsulfato sódico (SDS-PAGE) se evaluaron las diferencias en la expresión proteica entre los caracoles juveniles y adultos de los distintos subgrupos. Se calculó el coeficiente de similitud de Dice para determinar el porcentaje de bandas compartidas entre los subgrupos experimentales. Los resultados mostraron que la combinación de similitudes entre la edad y el estado de compatibilidad de los caracoles genera el mayor coeficiente de similitud seguido por el de la combinación de similitudes tanto de la edad como del origen genético aunque varían en el estado de compatibilidad. Por otra parte, las diferencias en los antecedentes genéticos, la edad y el estado de compatibilidad generan el índice de similitud más bajo. También se encontró que el antecedente genético en caracoles juveniles es importante en la determinación de su compatibilidad, mientras que el sistema de defensa interno es el que determina el nivel de compatibilidad en adultos. En conclusión, los resultados de este trabajo resaltan la importancia de la edad del caracol en conjunto con la genética y la defensa interna para determinar la compatibilidad de B. alexandrina/S.mansoni. Se recomienda realizar futuros trabajos así como una mayor caracterización de las bandas proteicas compartidas entre los subgrupos estudiados para esclarecer su papel en la relación hospedero-parásito.
Subject(s)
Animals , Biomphalaria/parasitology , Biomphalaria/chemistry , Schistosomiasis mansoni/parasitology , Proteins/analysis , Reference Values , Biomphalaria/genetics , Biomarkers/analysis , Proteins/genetics , Age Factors , Electrophoresis, Polyacrylamide Gel , Host-Parasite Interactions , Molecular WeightABSTRACT
Of the approximately 34 identified
Subject(s)
Animals , Female , Male , Mice , Biomphalaria/parasitology , Host-Parasite Interactions/genetics , Schistosoma mansoni/physiology , Age Factors , Alleles , Biomphalaria/enzymology , Biomphalaria/genetics , Superoxide Dismutase/analysisABSTRACT
The African species of Biomphalaria appeared as a result of the relatively recent west-to-east trans-Atlantic dispersal of the Biomphalaria glabrata-like taxon. In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. Biomphalaria alexandrina originated in the area between Alexandria and Rosetta and has historically been confined to the Nile Delta. Schistosoma mansoni reached Egypt via infected slaves and baboons from the Land of Punt through migrations that occurred as early as the Vth Dynasty. The suggestion of the presence of Schistosoma mansoni infection in Lower Egypt during Pharaonic times is discussed despite the fact that that there is no evidence of such infection in Egyptian mummies. It is only recently that Biomphalaria alexandrina colonized the Egyptian Nile from the Delta to Lake Nasser. This change was likely due to the construction of huge water projects, the development of new water resources essential for land reclamation projects and the movement of refugees from the Suez Canal zone to the Delta and vice versa. The situation with respect to Biomphalaria in Egypt has become complicated in recent years by the detection of Biomphalaria glabrata and a hybrid between both species; however, follow-up studies have demonstrated the disappearance of such species within Egypt. The National Schistosoma Control Program has made great strides with respect to the eradication of schistosoma; however, there has unfortunately been a reemergence of Schistosoma mansoni resistant to praziquantel. There are numerous factors that may influence the prevalence of snails in Egypt, including the construction of water projects, the increase in reclaimed areas, global climate change and pollution. Thus, continued field studies in addition to the cooperation of several scientists are needed to obtain an accurate representation of the status of this species. In addition, the determination of the genome sequence for Biomphalaria alexandrina and the use of modern technology will allow for the study of the host–parasite relationship at a molecular level.
ABSTRACT
Objective: To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes. Methods:Susceptible laboratory-bred Biomphalaria alexandrina (B. alexandrina) snails were exposed to lab-maintained rotifers; Philodina spp., two weeks before and after being infected with Schistosoma mansoni (S. mansoni) miracidia. The consequent histopathological impact on snail tissues and cercarial biology were investigated before and after emergence from snails. Results:Contamination of B. alexandrina snails with philodina, two weeks before miracidial exposure, was found to hinder the preliminary development of S. mansoni cercariae inside the snail tissues. Furthermore, when snails were contaminated with rotifers two weeks post miracidial exposure; growth of already established cercariae was found to be retarded. The consequent influence of internalized rotifers within the snail tissue was clearly reflected on cercarial emergence, activity and infectivity along the four weeks duration of shedding. In the present study, comparison of snail histopathological findings and altered cercarial biology observed between the experimental and control groups indicated that the rotifers may have affected the levels of snail's energy reservoirs, which eventually was found to have had an adverse impact on reproduction, growth and survival of the parasite within the snail host, coupled with its performance outside the snail. Conclusions:In future biological control strategies of schistosomiasis, ritifers should be considered as a parasitic scourge of humanity.
ABSTRACT
Objective: To test Candonocypris novaezelandiae (Baird) (C. novaezelandiae), sub-class Ostracoda, obtained from the Nile, Egypt for its predatory activity on snail, Biomphalariaalexandrina (B. alexandrina), intermediate host of Schistosoma mansoni (S. mansoni) and on the free-living larval stages of this parasite (miracidia and cercariae). Methods:The predatory activity of C. novaezelandiae was determined on B. alexandrina snail (several densities of eggs, newly hatched and juveniles). This activity was also determined on S. mansoni miracidia and cercariae using different volumes of water and different numbers of larvae. C. novaezelandiae was also tested for its effect on infection of snails and on the cercarial production. Results: C. novaezelandiae was found to feed on the eggs, newly hatched and juvenile snails, but with significant reduction in the consumption in the presence of other diet like the blue green algae (Nostoc muscorum). This ostracod also showed considerable predatory activity on the free-living larval stages of S. mansoni which was affected by certain environmental factors such as volume of water, density of C. novaezelandiae and number of larvae of the parasite.Conclusions:The presence of this ostracod in the aquatic habitat led to significant reduction of snail population, infection rate of snails with schistosme miracidia as well as of cercarial production from the infected snails. This may suggest that introducing C. novaezelandiae into the habitat at schistosome risky sites could suppress the transmission of the disease.
ABSTRACT
<p><b>OBJECTIVE</b>To test Candonocypris novaezelandiae (Baird) (C. novaezelandiae), sub-class Ostracoda, obtained from the Nile, Egypt for its predatory activity on snail, Biomphalaria alexandrina (B. alexandrina), intermediate host of Schistosoma mansoni (S. mansoni) and on the free-living larval stages of this parasite (miracidia and cercariae).</p><p><b>METHODS</b>The predatory activity of C. novaezelandiae was determined on B. alexandrina snail (several densities of eggs, newly hatched and juveniles). This activity was also determined on S. mansoni miracidia and cercariae using different volumes of water and different numbers of larvae. C. novaezelandiae was also tested for its effect on infection of snails and on the cercarial production.</p><p><b>RESULTS</b>C. novaezelandiae was found to feed on the eggs, newly hatched and juvenile snails, but with significant reduction in the consumption in the presence of other diet like the blue green algae (Nostoc muscorum). This ostracod also showed considerable predatory activity on the free-living larval stages of S. mansoni which was affected by certain environmental factors such as volume of water, density of C. novaezelandiae and number of larvae of the parasite.</p><p><b>CONCLUSIONS</b>The presence of this ostracod in the aquatic habitat led to significant reduction of snail population, infection rate of snails with schistosme miracidia as well as of cercarial production from the infected snails. This may suggest that introducing C. novaezelandiae into the habitat at schistosome risky sites could suppress the transmission of the disease.</p>
Subject(s)
Animals , Crustacea , Physiology , Pest Control , Pest Control, Biological , Predatory Behavior , Schistosoma mansoni , Schistosomiasis mansoniABSTRACT
In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. The fates of Schistosoma miracidia in the snails varies between different species of Biomphalaria. The internal defense system is one of the factors that influence the susceptibility pattern of the snails. The interaction between Biomphalaria snails and S. mansoni needs to be identified for each species, and even between the members of the same species with different degrees of susceptibility. In the present study, the first generation of susceptible and resistant parents of B. alexandrina was examined histologically at the 30th day post exposure. The study includes the characterization of the immune response, as expressed by tissue reactions, of susceptible and resistant B. alexandrina snails against S. mansoni. It was also designed to determine the impact of the resistance increase in parent snails, on the mechanisms of interaction of their offspring against infection. The results showed that the infection rate of the offspring from the susceptible parents was 92%. No susceptible offspring was produced from the resistant parents. When the parents were of equal number of susceptible and resistant snails, they gave an offspring with an infection rate of 20%. Susceptible snails that had susceptible parents showed a higher degree of susceptibility than those that had both susceptible and resistant parents. A common feature of the resistant snails was the absence of any viable parasites. The tissue reactions of the resistant snails having only resistant parents occurred at the site of miracidial penetration. In resistant snails for which susceptible ones were included in their parents, the reactions occurred in the deep tissues. These results characterized the immune response of B. alexandrina snails against Schistosoma infection which was found to occur by two different mechanisms. One type of defense occurs in highly resistant snails, and employs direct miracidial destruction soon after parasite penetration. The other type occurs in less resistant snails where a delayed resistance development occurs after the dissemination of the sporocysts in the snail tissues. It seems that B. alexandrina snails respond more or less similar to B. glabrata. The results also proved that the immune response of the internal defense system increased with increasing the number of the inherited resistant genes.
En Egipto, Biomphalaria alexandrina es el huésped intermediario de Schistosoma mansoni. La supervivencia de los miracidios de Schistosoma en los caracoles varía entre las especies de Biomphalaria. El sistema de defensa interno es uno de los factores que influyen en el patrón de susceptibilidad de los caracoles. La interacción entre los caracoles Biomphalaria y S. mansoni requiere ser identificada para cada especie e incluso, entre los miembros de la misma especie con diferente grado de susceptibilidad. En el presente estudio, la primera generación de padres susceptibles y resistentes de B. alejandrina fue examinada histológicamente al día 30, después de la exposición. El trabajo fue realizado tanto para caracterizar la respuesta inmune, según las reacciones de los tejidos, de los caracoles susceptibles y resistentes de B. alejandrina contra S. mansoni. También, el estudio se diseñó para determinar el impacto en el aumento de la resistencia en los caracoles padres, en los mecanismos de interacción de sus crías contra la infección. Los resultados mostraron que la tasa de infección para las crías, de padres susceptibles, fue del 92%. No se originaron crías susceptibles de los padres resistentes. Cuando los padres incluían un número igual de caracoles susceptibles y resistentes, dieron como resultado crías con una tasa de infección del 20%. Los caracoles susceptibles que tuvieron padres susceptibles mostraron un mayor grado de susceptibilidad que los que tenían tanto padres sensibles como resistentes. Una característica común de los caracoles resistentes fue la ausencia de parásitos viables. Las reacciones en los tejidos de los caracoles resistentes de sólo padres resistentes ocurrió en el sitio de penetración del miracidio. En los caracoles resistentes, para los que variedades susceptibles fueron incluídas entre sus padres, las reacciones se produjeron en tejidos profundos. Los resultados caracterizaron la respuesta inmune de los caracoles B. alexandrina contra la infección por Schistosoma, que ocurre por dos mecanismos diferentes. El primer tipo de defensa la cual se produce en los caracoles con alta resistencia, utiliza la destrucción directa del miracidio poco después de la penetración de los parásitos. El segundo tipo se produce en los caracoles menos resistentes, en el cual se después de la difusión de los esporocistos en los tejidos del caracol. Parece que los caracoles B. alexandrina responden de una manera más o menos similar a B. glabrata. Los resultados también demostraron que la respuesta inmune del sistema de defensa interna aumentó cuando en el número de genes de resistencia heredados es mayor.
Subject(s)
Animals , Biomphalaria/parasitology , Host-Parasite Interactions/physiology , Schistosoma mansoni/physiology , Disease Susceptibility , Schistosoma mansoni/pathogenicityABSTRACT
In the present study, Biomphalaria snails collected from five Egyptian governorates (Giza, Fayoum, Kafr El-Sheikh, Ismailia and Damietta), as well as reference control Biomphalaria alexandrina snails from the Schistosome Biological Supply Center (SBSC) (Theodor Bilharz Research Institute, Egypt), were subjected to species-specific polymerase chain reaction (PCR) assays to identify the collected species. All of the collected snails were found to be B. alexandrina and there was no evidence of the presence of Biomphalaria glabrata. Randomly amplified polymorphic DNA (RAPD)-PCR assays showed different fingerprints with varying numbers of bands for the first generation (F1) of B. alexandrina snail populations (SBSC, Giza, Fayoum, Kafr El-Sheikh, Ismailia and Damietta). The primer OPA-1 produced the highest level of polymorphism and amplified the greatest number of specific bands. The estimated similarity coefficients among the B. alexandrina populations based on the RAPD-PCR profiles ranged from 0.56 (between SBSC and Ismailia snails) to 0.72 (between Ismailia and Kafr El-Sheikh snails). Experimental infection of the F1 of progeny from the collected snails with Schistosoma mansoni (SBSC strain) showed variable susceptibility rates ranging from 15% in the Fayoum snail group to 50.3% in SBSC snails. A negative correlation was observed between the infection rates in the different snail groups and the distances separating their corresponding governorates from the parasite source. The infection rates of the snail groups and their similarity coefficients with SBSC B. alexandrina snails were positively correlated. The variations in the rates of infection of different B. alexandrina groups with S. mansoni, as well as the differences in the similarity coefficients among these snails, are dependent not only on the geographical distribution of the snails and the parasite, but also on the genetic variability of the snails. Introduction of this variability into endemic areas may reduce the ability of the parasite to infect local hosts and consequently reduce schistosomiasis epidemiology.
Subject(s)
Animals , Biomphalaria/genetics , Biomphalaria/parasitology , Disease Vectors , Genetic Variation/genetics , Host-Parasite Interactions/genetics , Schistosoma mansoni/physiology , Egypt , Random Amplified Polymorphic DNA TechniqueABSTRACT
Carboxylic acids play an important role in both aerobic and anaerobic metabolic pathways of both the snail and the parasite. Monitoring the effects of infection by schistosome on Biomphalaria alexandrina carboxylic acids metabolic profiles represents a promising additional source of information about the state of metabolic system. We separated and quantified pyruvic, fumaric, malic, oxalic, and acetic acids using ion-suppression reversed-phase high performance liquid chromatography (HPLC) to detect correlations between these acids in both hemolymph and digestive gland gonad complex (DGG's) samples in a total of 300 B. alexandrina snails (150 infected and 150 controls) at different stages of infection. The results showed that the majority of metabolite pairs did not show significant correlations. However, some high correlations were found between the studied acids within the control group but not in other groups. More striking was the existence of reversed correlations between the same acids at different stages of infection. Some possible explanations of the underlying mechanisms were discussed. Ultimately, however, further data are required for resolving the responsible regulatory events. These findings highlight the potential of metabolomics as a novel approach for fundamental investigations of host-pathogen interactions as well as disease surveillance and control.
Subject(s)
Animals , Biomphalaria/chemistry , Carboxylic Acids/analysis , Chromatography, High Pressure Liquid , Gastrointestinal Tract/chemistry , Hemolymph/chemistry , Schistosoma mansoni/chemistryABSTRACT
Despite effective chemotherapy, schistosomiasis remains the second largest public health problem in the developing world. Currently, vaccination is the new strategy for schistosomiasis control. The presence of common antigenic fractions between Schistosoma mansoni and its intermediate host provides a source for the preparation of a proper vaccine. The objective of this paper is to evaluate the nucleoprotein extracted from either susceptible or resistant snails to protect against schistosomiasis. The vaccination schedule consisted of a subcutaneous injection of 50 µg protein of each antigen followed by another inoculation 15 days later. Analyses of marker enzymes for different cell organelles [succinate dehydrogenase, lactate dehydrogenase (LDH), glucose-6-phosphatase, acid phosphatase and 5'-nucleotidase] were carried out. Energetic parameters (ATP, ADP, AMP, phosphate potentials, inorganic phosphate, amino acids and LDH isoenzymes) were also investigated. The work was extended to record worm and ova counts, oogram determination in the liver and intestine and the histopathological pattern of the liver. The nucleoprotein of susceptible snails showed reduction in worm and ova counts by 70.96 percent and 51.31 percent, respectively, whereas the nucleoprotein of resistant snails showed reductions of 9.67 percent and 16.77 percent, respectively. In conclusion, we found that the nucleoprotein of susceptible snails was more effective in protecting against schistosomiasis.
Subject(s)
Animals , Male , Mice , Amino Acids , Biomphalaria , Liver , Nucleoproteins/immunology , Schistosoma mansoni/immunology , Schistosomiasis mansoni/immunology , Biomphalaria/immunology , Host-Parasite Interactions , Liver , Liver/enzymology , Liver/pathology , Nucleoproteins , Parasite Egg Count , Schistosomiasis mansoniABSTRACT
In this study, we looked at the inheritance of susceptibility and resistance to Schistosoma mansoni infection in the first generation of crossbred Biomphalaria alexandrina snails. Our ultimate goal is to use such information to develop a biological method of controlling schistosomiasis. We infected laboratory-bred snails with S. mansoni miracidia and examined cercarial shedding to determine susceptibility and resistance. Five parental groups were used: Group I contained 30 susceptible snails, Group II contained 30 resistant snails, Group III contained 15 susceptible and 15 resistant snails, Group IV contained 27 susceptible and three resistant snails and Group V contained three susceptible and 27 resistant snails. The percentage of resistant snails in the resulting progeny varied according to the ratio of susceptible and resistant parents per group; they are 7 percent, 100 percent, 68 percent, 45 percent and 97 percent from Groups I, II, III, IV and V, respectively. On increasing the percentage of resistant parent snails, the percentage of resistant progeny increased, while cercarial production in their susceptible progeny decreased.