Ocotea pulchellaas an alternative against schistosomiasis: chemical analysis, development of nanoemulsion and biological control activity / Ocotea pulchellacomo una alternativa ante esquistosomiasis: análisis químico, desarrollo de una nanoemulsión y actividad en control biológico

The aim of this work was to evaluate the potential of the essential oil (EO) from Ocotea pulchella leaves as an alternative in the control of schistosomiasis. It was tested O. pulchella EO nanoformulation to assess its activity against adult Biomphalaria glabrata, their spawning and Schistossoma mansoni cercariae. Additionally, the EO chemical composition was investigated by gas-chromatography. Nanoemulsion were elaborated by the low energy method. The adult mollusks, their spawning and cercariae were placed in contact with nanoemulsion to calculate lethal concentrations. Myristicin, bicyclogermacrene and α-Pinene were the main substances in the EO. Nanoemulsion caused mortality of adult B. glabrata, its egg embryos and S. mansoni. These results suggest the use of this nanoemulsion as an alternative in the control of the schistosomiasis cycle.

El objetivo de este trabajo fue evaluar el potencial de los aceites esenciales (AE) de las hojas de Ocotea pulchellacomo una alternativa en el control de esquistosomiasis. Se probó una nanoformulación de AE de O. pulchellapara evaluar su actividad ante adultos de Biomphalaria glabrata, sus huevos y cercarías de Schistossoma mansoni. La nanoemulsión fue elaborada por el método de baja energía. Los moluscos adultos, sus huevos y cercarías se colocaron en contacto con la nanoemulsión para calcular concentraciones letales. Los compuestos mayoritarios en el AE fueron miristicina, biciclogermacreno y α-pineno. La nanoemulsión causó mortalidad en adultos de B. glabrata, sus huevos y a S. mansoni. Los resultados sugieren el uso de esta nanoemulsión como una alternativa en el control del ciclo de esquistosomiasis.

Xiphidiocercariae from naturally infected Lymnaea columella (Mollusca, Gastropoda) in urban area: morphology and ultrastructure of the larvae and histological changes in the mollusc host / Xifidiocercárias obtidas em Lymnaea columella (Mollusca, Gastropoda) naturalmente infectadas em área urbana: morfologia e ultraestrutura da larva e alterações histológicas do molusco hospedeiro

Abstract Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.

Resumo Agricultura urbana é muito comum nas cidades, como Rio de Janeiro e adjacências, sendo uma importante atividade econômica de subsistência. No entanto, esta prática pode criar condições adequadas para o estabelecimento e manutenção do ciclo de vida de muitos parasitos. Os moluscos limneídeos podem atuar como hospedeiros intermédios de muitas espécies de trematódeos, incluindo aqueles que infectam humanos e animais selvagens e domésticos. No presente estudo, o molusco Lymnaea columella foi coletado de plantações urbanas de agrião e a morfologia das cercárias liberadas por eles foi analisada por microscopia eletrônica de varredura leve e de varredura. As larvas foram identificadas como xifidiocercárias, pertencentes ao grupo das Cercariae Ornatae, Ordem Plagiorchiiformes. Análises histológicas da glândula digestiva dos moluscos infectados evidenciaram esporocistos, com formação de granuloma e metaplasia do tecido epitelial.

Freshwater snails as the intermediate host of trematodes in Iran: a systematic review / 한국역학회지

Freshwater snails, as the first intermediate hosts of trematodes, can cause health hazards in animals and humans. Recently, the World Health Organization has included Iran in a list of 6 countries known to have serious problems with fascioliasis. In addition, cercarial dermatitis is a job-related disease that is seen often in paddy workers, agricultural labourers, and fishermen in Iran, particularly in Mazandaran Province. Many studies have been conducted in Iran to survey larval trematodes in freshwater snails. However, to the best of our knowledge, no comprehensive data exist regarding infections in gastropods. Therefore, the aim of the present study was to estimate the types and prevalence of cercarial infections in snails in Iran. Electronic English-language and Persian-language databases were searched to identify 24 published articles reporting the prevalence of trematode infections in snails (9 species from 6 families) in various provinces of Iran. In total, 4.4% of gastropods were infected with the larval stages of trematodes. According to the studies reviewed in this meta-analysis‚ the highest infection prevalence was found in Radix auricularia (9.9%). Twelve larval species of trematodes were identified, and the highest prevalence of cercariae was found for Echinostomatidae cercariae (4.3%). Among the provinces explored, West Azerbaijan had the highest prevalence of infected snails (16.9%). The presence of trematodes in snails could pose a serious health problem in Iran. Thus, further studies are necessary to characterize these infections in other provinces.

Freshwater snails as the intermediate host of trematodes in Iran: a systematic review / 한국역학회지

Freshwater snails, as the first intermediate hosts of trematodes, can cause health hazards in animals and humans. Recently, the World Health Organization has included Iran in a list of 6 countries known to have serious problems with fascioliasis. In addition, cercarial dermatitis is a job-related disease that is seen often in paddy workers, agricultural labourers, and fishermen in Iran, particularly in Mazandaran Province. Many studies have been conducted in Iran to survey larval trematodes in freshwater snails. However, to the best of our knowledge, no comprehensive data exist regarding infections in gastropods. Therefore, the aim of the present study was to estimate the types and prevalence of cercarial infections in snails in Iran. Electronic English-language and Persian-language databases were searched to identify 24 published articles reporting the prevalence of trematode infections in snails (9 species from 6 families) in various provinces of Iran. In total, 4.4% of gastropods were infected with the larval stages of trematodes. According to the studies reviewed in this meta-analysis‚ the highest infection prevalence was found in Radix auricularia (9.9%). Twelve larval species of trematodes were identified, and the highest prevalence of cercariae was found for Echinostomatidae cercariae (4.3%). Among the provinces explored, West Azerbaijan had the highest prevalence of infected snails (16.9%). The presence of trematodes in snails could pose a serious health problem in Iran. Thus, further studies are necessary to characterize these infections in other provinces.

Freshwater Snail Diversity in Mae Lao Agricultural Basin (Chiang Rai, Thailand) with a Focus on Larval Trematode Infections

The aim of this study was to conduct a freshwater snail survey in Mae Lao agricultural basin to assess the diversity with a focus on habitat types and their larval trematode infections. Snails were collected and examined in 14 sites of Mae Lao agricultural basin from August 2016 to October 2017. A total of 1,688 snail individuals were collected and classified into 7 families, 8 genera, and 12 species. Snail diversity and habitat types were higher in rice paddies than irrigation canals and streams. The most abundant species was Bithynia siamensis siamensis, representing 54.6% of the sample. Three species of snails act as first intermediate host were found with cercarial infections. They were Filopaludina sumatrensis polygramma, B. s. siamensis, and Melanoides tuberculata. The cercariae were categorized into 7 types; echinostome, monostome, gymnocephalous, virgulate, parapleurolophocercous, pleurolophocercous and megalurous cercariae. Parapleurolophocercous cercariae constituted the most common type of cercariae recovered, contributing 41.2% of all infections in snails. Echinostome metacercariae infections were found in 6 snail species with 7.6% prevalence. In addition, the metacercaria of avian trematode, Thapariella sp. were found in Filopaludina spp. snails and B. funiculata with a prevalence of 0.5%. This is the first report for Thapariella metacercariae in the snail host, B. funiculata, and also confirmed that viviparid and bithyniid snails act as the second intermediate hosts of this trematode. This work will provide new information on the distribution and intermediate host of trematode in this area.

Host-parasite relationship between Biomphalaria amazonica (Paraense, 1966) and Schistosoma mansoni (Sambon, 1907) / Relação parasito-hospedeiro entre Biomphalaria amazonica e Schistosoma mansoni

Abstract Biomphalaria amazonica is a planorbid species considered a potential host of Schistosoma mansoni. It is widely distributed in the Neotropical zone, particularly in the North and Centre-West of Brazil and in the North of Bolivia. The aim of the present study was to determine the host-parasite relationship between B. amazonica and S. mansoni (BH and SJ strains). Specimens of B. amazonica and their snail-conditioned water were examined in terms of their ability to attract miracidia. The infectivity of the mollusks was determined by exposing them to 20 miracidia of both strains. Sporocyst development and amebocyte reactions were studied after each mollusk specimen was exposed to 100 miracidia. Although no cercariae were eliminated, specimens of B. amazonica proved capable of attracting 77% of the miracidia they were exposed to. Viable sporocysts with no amebocyte reaction were found 96 hours after the exposure to miracidia. These results indicate the susceptibility of B. amazonica to the BH and SJ strains of S. mansoni, and therefore demonstrate the importance of this planorbid species as a potential vector of the trematode in the areas where it occurs.

Resumo Biomphalaria amazonica é uma espécie de planorbídeo considerada vetora potencial do Schistosoma mansoni. É amplamente distribuída na zona neotropical, especialmente no Norte e Centro-Oeste do Brasil e Norte da Bolívia. O presente trabalho teve por objetivo estudar a relação parasito-hospedeiro entre B. amazonica e S. mansoni (linhagens BH e SJ). Espécimes de B. amazonica e sua água de condicionamento foram examinados em relação à sua capacidade de atração miraxonal. A infectividade dos moluscos foi testada expondo-os a 20 miracídios de ambas as linhagens. A viabilidade dos esporocistos e o desenvolvimento de reações amebocitárias foram estudados após cada molusco ser exposto a 100 miracídios. Apesar de não eliminarem cercárias, B. amazonica provou ser capaz de atrair 77% dos miracídios a que foram expostos. Esporocistos viáveis sem reação amebócitaria foram encontrados 96 horas após a exposição aos miracídios. Esses resultados indicam a suscetibilidade de B. amazonica às linhagens BH e SJ de S. mansoni e, portanto, demonstram a importância desta espécie de planorbídeo como um vetor potencial do trematodeo na área onde ele ocorre.

In vivo and in vitro activity of oil extract of garlic (Allium sativum Linnaeus) against Schistosoma japonicum cercariae

Abstract: INTRODUCTION: The activity of garlic oil extract against Schistosoma japonicum cercariae was evaluated. METHODS: The in vitro and in vivo cercaricidal activities against S. japonicum larvae were determined. RESULTS: Exposure to ≥ 10-6 (v/v) garlic emulsions for 30 min led to 100% cercariae mortality; pre-exposure treatment with ≥ 10-4 (v/v) garlic emulsions showed 100% preventive efficacy against S. japonicum infection, while pre-treatment with 10-5 and 10-6 (v/v) emulsions achieved 20%-40% preventive efficacy and 35.2%-63.6% worm burden reduction. CONCLUSIONS: Garlic oil extract has activity against S. japonicum larvae and a promising preventive efficacy against S. japonicum infection.

Morphological Characteristics and Phylogenetic Trends of Trematode Cercariae in Freshwater Snails from Nakhon Nayok Province, Thailand

The prevalence of cercarial infection in freshwater snails and their evolutionary trends were studied in Nakhon Nayok province, Thailand. A total of 2,869 individual snails were examined for parasitic infections. The results showed that 12 snail species were found to host larval stages of trematodes with an overall prevalence of 4.7%. The infected specimens included 7 types at the cercarial stage; cercariae, megalurous cercariae, echinostome cercariae, furcocercous cercariae, parapleurolophocercous cercariae, virgulate cercariae, and xiphidiocercariae. Regarding molecular identification, ITS2 sequence data of each larval trematode were analyzed, and a dendrogram was constructed using the neighbor-joining method with 10,000 replicates. The dendrogram was separated into 6 clades (order/family), including Echinostomatida/Echinostomatidae, Echinostomatida/Philophthalmidae, Opisthorchiida/Heterophyidae, Plagiorchiida/Prosthogonimidae, Plagiorchiida/Lecithodendriidae, and Strigeatida/Cyathocotylidae. These findings were used to confirm morphological characteristics and evolutionary trends of each type of cercariae discovered in Nakhon Nayok province. Furthermore, this investigation confirmed that the ITS2 data of cercariae could be used to study on phylogenetic relationships or to determine classification of this species at order and/or family level when possible.

Gestation and breastfeeding in schistosomotic mothers differently modulate the immune response of adult offspring to postnatal Schistosoma mansoni infection

Schistosoma mansoni antigens in the early life alter homologous and heterologous immunity during postnatal infections. We evaluate the immunity to parasite antigens and ovalbumin (OA) in adult mice born/suckled by schistosomotic mothers. Newborns were divided into: born (BIM), suckled (SIM) or born/suckled (BSIM) in schistosomotic mothers, and animals from noninfected mothers (control). When adults, the mice were infected and compared the hepatic granuloma size and cellularity. Some animals were OA + adjuvant immunised. We evaluated hypersensitivity reactions (HR), antibodies levels (IgG1/IgG2a) anti-soluble egg antigen and anti-soluble worm antigen preparation, and anti-OA, cytokine production, and CD4+FoxP3+T-cells by splenocytes. Compared to control group, BIM mice showed a greater quantity of granulomas and collagen deposition, whereas SIM and BSIM presented smaller granulomas. BSIM group exhibited the lowest levels of anti-parasite antibodies. For anti-OA immunity, immediate HR was suppressed in all groups, with greater intensity in SIM mice accompanied of the remarkable level of basal CD4+FoxP3+T-cells. BIM and SIM groups produced less interleukin (IL)-4 and interferon (IFN)-g. In BSIM, there was higher production of IL-10 and IFN-g, but lower levels of IL-4 and CD4+FoxP3+T-cells. Thus, pregnancy in schistosomotic mothers intensified hepatic fibrosis, whereas breastfeeding diminished granulomas in descendants. Separately, pregnancy and breastfeeding could suppress heterologous immunity; however, when combined, the responses could be partially restored in infected descendants.

Conservation and developmental expression of ubiquitin isopeptidases in Schistosoma mansoni

Several genes related to the ubiquitin (Ub)-proteasome pathway, including those coding for proteasome subunits and conjugation enzymes, are differentially expressed during the Schistosoma mansoni life cycle. Although deubiquitinating enzymes have been reported to be negative regulators of protein ubiquitination and shown to play an important role in Ub-dependent processes, little is known about their role in S. mansoni . In this study, we analysed the Ub carboxyl-terminal hydrolase (UCHs) proteins found in the database of the parasite’s genome. An in silico ana- lysis (GeneDB and MEROPS) identified three different UCH family members in the genome, Sm UCH-L3, Sm UCH-L5 and Sm BAP-1 and a phylogenetic analysis confirmed the evolutionary conservation of the proteins. We performed quantitative reverse transcription-polymerase chain reaction and observed a differential expression profile for all of the investigated transcripts between the cercariae and adult worm stages. These results were corroborated by low rates of Z-Arg-Leu-Arg-Gly-Gly-AMC hydrolysis in a crude extract obtained from cercariae in parallel with high Ub conjugate levels in the same extracts. We suggest that the accumulation of ubiquitinated proteins in the cercaria and early schistosomulum stages is related to a decrease in 26S proteasome activity. Taken together, our data suggest that UCH family members contribute to regulating the activity of the Ub-proteasome system during the life cycle of this parasite.

Description of two new cercariae [an echinostome cercaria and a xiphidiocercaria] procured from biomphalaria pfeifferi [Krauss] from Nigeria

During parasitological examination of Biomphalaria pfeifferi snails obtained from Niger state [Nigeria], 2 new types of cercariae were found. They are identified to the level of referring to the major group and described here for the first time. They were examined viable and stained with vital stains as well as fixed in 70% alcohol. They were drawn with a camera lucida and photographed. They are identified as an echinostome cercaria and a xiphidiocercaria. The echinostome is characterized by having a ventral sucker almost double in size the oral one. It has a semicircular structure located beyond the oral sucker. Three pairs of penetration glands are found at the anterior portion of the body. The number of collar spines is relatively large [44-46]. The flame cells are 17x2 in number. Two main lateral excretory ducts extend anteriorly, form two typical echinostome loops then pass posteriorly to open together in a diverticulat-ed excretory vesicle. Its tail is relatively long and flattened with 3 fin folds. The tail [640 microm] is longer than the body [475microm].The xiphidiocercaria belongs to the [ornatae] group. It is relatively small [180.5x110microm] with a long stylet [3'0nm]. Its oral sucker is one and half times the size of the ventral sucker. Two excretory ducts extend posteriorly in both sides and become dilated and unite to open in a circular excretory vesicle. Tail is slender shorter than the body and has a dorso-ventral fin fold. Key words: Echinostome cercaria, xixphidiocercaria, Biomphalaria pfeifferi

Epidemiology of cercarial stage of trematodes in freshwater snails from Chiang Mai province, Thailand

<p><b>OBJECTIVE</b>To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand.</p><p><b>METHODS</b>The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012. The prevalence of cercarial infection in snails was investigated using the crushing method. The drawing was done with the help of a camera lucida for the morphological study.</p><p><b>RESULTS</b>A total of 2 479 snail individuals were collected and classified into 7 families, 11 genera, and 14 species, Among them, 8 snails species were found to be infected with an overall prevalence of 17.27% (428/2 479), which infected with nine groups of cercariae; gymnocephalous cercaria, strigea cercaria, megalurous cercaria, monostome cercaria, parapleurolophocercous cercaria (Haplorchis cercaria), pleurolophocercous cercaria, furcocercous cercaria (Transversotrema cercaria), xiphidiocercaria, and virgulate cercaria. The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails (64.25%).</p><p><b>CONCLUSIONS</b>The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals. This work will provide new information on both the distribution and first intermediate host of trematodes.</p>

Schistosoma mansoni cercarial host location and infection under simulated natural conditions in Egypt

This study was performed in water ditches under simulated natural conditions in Egypt to elucidate the effect of various environmental factors on Schistosoma mansoni cercarial host location and infection of the definitive host [using albino mice]. Evaluation of these factors was dependent on both infection rate of exposed mice as well as the schistosome worm load under the same experimental conditions. The seasonal water temperature proved to be a very important factor and this was proven by the infection rate of mice and the worm load recovered were lower in January and April [16°C and 22°C midday water temperature] and much higher in July and October [29°C and 25°C]. The daytime factor is similarly important as temperature illustrated by the schistosome infection of mice groups exposed at 8-10 am was much higher than in groups exposed between 1pm and 3pm [p<0.001]. The greatest infection rate of mice and worm load were obtained when the shedding snails were close to the exposed group of mice. Both criteria increased with the increase of cercarial density in the water. The length of exposure period is also an extremely important factor for schistosome infection, being highest 87.5% [p<0.001] in3 hours exposure period. Infection rate was found to be 88.2% and 55.6% of shedding snails were located at water surface and midway to the bottom, respectively, and no infection occurred when located at the bottom. The schistosome infection of mice decreased in presence of increasing density of the floating plant Eichhornia crassipes in the ditch water, but low condensation of the submersed plant Ceratophyllum demersum appeared to have stimulating effect

Development and effects of schistosoma japonicum [trematoda] on its intermediate host, oncomelania hupensis [gastropoda]

Trematodes belonging to the genus Schistosoma cause schistosomiasis. The relationship between schistosomes and their intermediate hosts varies among snails. This study investigated the effects of S. japonicum on its snail host, Oncomelania hupensis, and cercarial release rythmicity of S. japonicum and the effects of light on it. Seven groups of O. hupensis [n = 40 each] were exposed individually to 0 [control], 2, 4, 6, 10, 15, and 20 S. japonicum miracidia. Mortality of the snails was recorded for 10 weeks. Snails in each group were checked for infection at seven weeks post-exposure. Positive snails were exposed to arti-ficial light from 06:00 am - 18:00 pm and the liberated cercariae were collected every 2 hours to de-termine the rhythmicity of cercarial release. Three groups of positive snails [n = 6 each] were ex-posed to artificial light, daylight, and darkness from 06:00 am - 18:00 pm, the liberated cercariae were collected every 2 hours to determine the effects of light. The highest infection rate and host mortality occurred among snails in the groups exposed to 15 and 20 miracidia. Cercariae were liberated after eight weeks of exposure of O. hupensis to S. japonicum. The circarial emerging pattern was circadian, with a single peak of emerging between 10:00 am and 12:00 pm. Light intensity had a positive influence on cercariae shedding and rhythmicity. Further research, including the influence of biotic and abiotic factors is deemed necessary to fine-tune elucidation of the effects of S. japonicum upon O. hupensis snail.

Cercaria caribbea LVIII Cable, 1963 (Digenea: Cyathocotylidae) in the Republic of Korea and Its Surface Ultrastructure

Cercaria caribbea LVIII Cable, 1963 (Digenea: Cyathocotylidae) was detected from a brackish water gastropod species (Cerithideopsilla cingulata) in a coatal area of Shinan-gun, Jeollanam-do (Province), the Republic of Korea, and its surface ultrastructure was studied using a scanning electron microscope. The cercariae were found freely swimming or enveloped within daughter sporocysts when the snail host was mechanically broken. They were morphologically characterized by a linguiform and ventrally concave body, a long and bifurcated tail, and the presence of a holdfast (=tribocytic) organ posterior to the ventral sucker. On the whole ventral and dorsal surfaces, peg-like tegumental spines were densely distributed. Around the oral sucker, several sensory papillae, each with a short cilium, were distributed, and on the tail, sensory papillae, each with an extensively long cilium, were observed. This is the first record describing a cyathocotylid cercaria from a brackish water gastropod in the Republic of Korea.

A combined proteomic and immunologic approach for the analysis of Schistosoma mansoni cercariae and adult worm protein extracts and the detection of one of the vaccine candidates, Sm28GST, from a Venezuelan parasite isolate / Aproximación al análisis proteómico e inmunológico de extractos proteicos de cercaria y verme adulto de Schistosoma mansoni y detección de uno de los candidatos a vacuna, Sm28GST, de un aislado venezolano

Understanding the mode of Schistosoma mansoni larval invasion and the mechanism of immune evasion utilized by larvae and adult worms is essential for a rational development of vaccines or drugs to prevent or cure the disease. This parasite has a very complex molecular organization in all parasite stages, and identifying the major parasite proteins would give clues to schistosome metabolism and to the interaction of the parasite with the host immune system. Our goal was the evaluation of the protein parasite repertoire using a proteomic approach, and the characterization of protein extracts from two different parasite stages of a Venezuelan isolate, such as cercariae and adult worms, previously performed by other authors in some other strains. A comparison among authors was made. Besides, we aimed to identify different isoforms of one of the vaccine candidates, the gluthation-S-transferase protein (Sm28GST), by 2D SDS-PAGE and mass spectrometry, and to achieve its immunologic detection using sera from rabbits immunized with synthetic peptides derived from the Sm28GST protein. These techniques allowed the identification of some of the target molecules of the protective immune response that are being evaluated as potential members of a multi-component and multi-stage anti-S. mansoni vaccine and to clarify if the selected peptides induce antibodies that are able to recognize different isoforms of the Sm28GST.

Es esencial comprender la forma como las larvas de Schistosoma mansoni invaden y los mecanismos de evasión inmune utilizados por larvas y adultos, para el desarrollo racional de vacunas o drogas para prevenir o curar la esquistosomiasis. Este parásito tiene una organización molecular muy compleja en todos sus estadíos, por lo que la identificación de las proteínas más importantes es clave para investigar el metabolismo del esquistosoma y la interacción del parásito con el sistema inmune del hospedero. El objetivo de este trabajo fue evaluar el repertorio proteico del parásito utilizando una aproximación proteómica y la caracterización de extractos proteicos de dos estadios parasitarios diferentes de un aislado venezolano, como la cercaria y el verme adulto, previamente realizado por otros autores en otras aislados. Se realizó una comparación entre autores. Además, se identificaron diferentes isoformas de uno de los candidatos a vacuna, la glutation S transferasa (Sm28GST) por 2D SDS-PAGE y espectrometría de masas y se logró su detección inmunológica, usando sueros de conejos inmunizados con péptidos sintéticos derivados de la proteína Sm28GST. Estas técnicas permitieron identificar algunas de las moléculas blanco de la respuesta inmune protectora que están siendo evaluados como miembros potenciales de una vacuna multi-estadio y multi-componente y aclarar si los péptidos seleccionados indujeron anticuerpos capaces de reconocer diferentes isoformas de la Sm28GST.

Larval stages of digenetic trematodes in Melanopsis praemorsa snails from freshwater bodies in Palestine

<p><b>OBJECTIVE</b>To detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine.</p><p><b>METHODS</b>A total of 1 880 Melanopsis praemorsa snails were collected from different fresh water bodies in Palestine from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa snails were obtained by lighting and crushing methods. The behavior of cercariae was observed using a dissecting microscope.</p><p><b>RESULTS</b>Three different species of larval trematodes were identified from Melanopsis praemorsa snails collected only from Al-Bathan fresh water body, while snails from other water bodies were not infected. These species were microcercous cercaria, xiphidiocercaria and brevifurcate lophocercous cercaria. These cercariae called Cercaria melanopsi palestinia I, Cercaria melanopsi palestinia II and Cercaria melanopsi palestinia III have not been described before from this snail in Palestine. The infection rate of Melanopsis praemorsa collected from Al-Bathan fresh water body was 5.7%, while the overall infection rate of snails collected from all fresh water bodies was 4.3%. Details are presented on the morphology and behavior of the cercariae as well as their development within the snail.</p><p><b>CONCLUSIONS</b>These results have been recorded for the first time and these cercariae may be of medical and veterinary importance.</p>

Haemolymph components of infected and none infected lymnaea snails with xiphidiocercariae

In this study the haemolymph components of infected and none infected Lymnaea gedrosiana with xiphidiocercaria larvae was compared. Five hundred Fifty Lymnaea snails were collected from Ilam and Mazandaran provinces, Iran, during 2008-2009. The snails were transported to the lab at Tehran University of Medical Sciences and their cercarial sheddings were studied. Haemolmyphs of snails were extracted and cells were counted using haemocytometer and cell-surface carbohydrate were recognized by conjugated lectin [Lentil]. Haemolymph protein concentrations were measured by Bradford protein assay method and soluble protein compositions were determined on sodium dodecyl sulphate polyacrilamide gel electrophoresis [SDS-PAGE]. From the 550 examined Lymnaea snails for cercariae, 27 snails were infected with xiphidiocercariae. Mean of haemolymph cells [haemocyte] number were obtained 93480 +/- 2.43 [cells/ml] for none infected snails [25 snail] and 124560 +/- 2800 [cells/ml] for infected snails [25 snail]. Mannose carbohydrate was recognized on haemocyte of none infected and infected snails. Mean of protein concentration of haemolymph plasma was obtained as 1354 +/- 160 micro g/ml [1.4 mg/ml] for none infected snails [25 snails] and 1802 +/- 138 micro g/ml [1.8 mg/ml] for infected snail [25 snails]. Comparing to none infected snails, the SDS-PAGE results of haemolymph plasma of infected snails, showed an extra protein band [70 kDa]. The results showed a significant difference between the amounts and the kinds of proteins in haemolymph of infected and none infected snails. This information might be useful to understand of parasite detection, adhesion, engulfment and antigen agglutination by snail

Immuno-screening of Schistosoma japonicum cercariae cDNA library by the sera of anti-soluble cercariae 66 to approximately 68 kD antigens / 中南大学学报(医学版)

OBJECTIVE@#To obtain the coding genes related to Schistosoma japonicum (Sj) cercariae 66 to approximately 68 kD antigens,and to provide antigens for diagnosis and vaccine of schistosomiasis.@*METHODS@#Sj cercariae cDNA library was screened using the monospecific anti-sera of rabbit against soluble cercariae 66 to approximately 68 kD antigens as probes.The inserted cDNA fragments of the positive clones were amplified with PCR and identified by agarose gel electrophoresis. Four strong positive clones were further sequenced and analyzed through the internet NCBI/BLAST software.@*RESULTS@#Twenty-one positive clones were obtained, 10 of which revealed a single band (0.5 to approximately 3.0 kb).The 4 strong positive clones showed high identity to SJCHGC05187,SJCHGC05173,SJCHGC06989, and SJCHGC01894 at the nucleotide level.@*CONCLUSION@#Four coding genes related with Sj antigens are obtained.

faunistic survey of cercariae from fresh water snails: melanopsis spp. and their role in disease transmission

Snail transmitted diseases are one of the major group of helminth parasitic diseases which have been established by trematode parasites. The larvae of trematodes [cercariae] use the snails as host. The purpose of the present study was to identify of cercariae released from Melanopsis spp. [M. doriae, M. costata, M. praemorsa, and M. nodosa] and evaluate their medical importance. Accordingly, 2, 266 Melanopsis spp. [fresh water snails] were collected from various agriculture canals in the central area of Khuzestan Province in the south west of Iran. 72 [3.1%] infected Melanopsis spp. snails were isolated and the cercariae were obtained by emerging or crushing methods. Subsequently, measurement and drawing were made on cercariae specimens and recognized. In some cases experimental infections were established in the animals for further iden-tification. A total of 4 cercarial families and 1 cercarial group were identified as follows: Heterophyidae: Haplorchis pumilio, H. taithui, Stellantchasmus falcatus and Centrocestus formosanus; Echinostomatidae: Echinochasmus milvi; Cyathocotyli-dae, Philophthalmidae and Monostome group cercariae [probably Notocotylidae]. These results have been recorded for the first time and these cercariae are of medical and veterinary importance