| antioxidant gene expression and function in in vitro-developing schistosoma mansoni mother sporocysts: possible role in self-protection. | the ability of the larval forms of schistosoma mansoni to invade and parasitize their molluscan host, biomphalaria glabrata, is determined by a multitude of factors. in this study we sought to elucidate the possible mechanisms by which the invading larvae are able to counteract the potentially harmful oxidative environment presented by the host upon initial miracidial infection. this was attempted by examining the gene expression profile of parasite antioxidant enzymes of the linked glutathione- ... | 2007 | 17445325 |
| high performance column liquid chromatographic analysis of selected carboxylic acids in biomphalaria glabrata patently infected with schistosoma mansoni. | high-performance liquid chromatography (hplc) was used to determine the effects of a patent schistosoma mansoni infection on certain carboxylic acids in the digestive gland gonad complex (dgg) and hemolymph of biomphalaria glabrata. an analysis of dgg samples was done using extraction with 50% locke's solution, cleanup of the extract by anion exchange solid phase extraction (spe), and ion exclusion hplc with ultraviolet detection. hemolymph was applied directly to the spe column. acetic, fumaric ... | 2007 | 17483962 |
| evaluation of the effect of oxamniquine, praziquantel and a combination of both drugs on the intramolluscan phase of schistosoma mansoni. | the activity of oxamniquine (oxa), praziquantel (pzq), and a combination of both drugs was evaluated at the intramolluscan phase of schistosoma mansoni. biomphalaria glabrata snails infected with s. mansoni were treated with 500 mg/kg oxa, 1000 mg/kg pzq or with 250 mg/kg oxa and 500 mg/kg pzq, in association, at the pre-patent and patent phases of infection. the results showed that either treatments with oxa or pzq, alone, at the pre-patent period, delayed the parasite's development, increasing ... | 2007 | 17498638 |
| nimbus (bgi): an active non-ltr retrotransposon of the schistosoma mansoni snail host biomphalaria glabrata. | the freshwater snail biomphalaria glabrata is closely associated with the transmission of human schistosomiasis. an ecologically sound method has been proposed to control schistosomiasis using genetically modified snails to displace endemic, susceptible ones. to assess the viability of this form of biological control, studies towards understanding the molecular makeup of the snail relative to the presence of endogenous mobile genetic elements are being undertaken since they can be exploited for ... | 2007 | 17521654 |
| interplay between host genetic variation and parasite transmission in the biomphalaria glabrata-schistosoma mansoni system. | genetic variability is often predicted to enhance host fitness in the face of parasitism, yet this idea is rarely tested in an experimental setting, particularly with animal hosts. to assess this question, we used a relatively resistant line of snail hosts (biomphalaria glabrata) to generate inbred and outcrossed progeny that were then either exposed or sham-exposed to the trematode parasite, schistosoma mansoni. results showed no difference in prevalence between the groups; however, large diffe ... | 2007 | 17564726 |
| is host-schistosome coevolution going anywhere? | that pathogens and hosts coevolve is a powerful concept with broad theoretical and applied implications spanning from genetic theory to the medical and veterinary sciences, particularly in the context of infectious disease epidemiology. a substantial body of theory has been developed to explore the likelihood and consequences of coevolution, but few empirical studies have been conducted to test these theories, particularly for indirectly-transmitted pathogen-host systems. we initiated replicate ... | 2007 | 17567519 |
| excretory-secretory proteome of larval schistosoma mansoni and echinostoma caproni, two parasites of biomphalaria glabrata. | schistosoma mansoni and echinostoma caproni are two trematode species that use different strategies (mimicry and immunosuppression, respectively) to interfere with the snail innate immune system. parasites excretory-secretory (es) products have been shown to play a key role in these host-parasite immune interactions. however, they remain largely uncharacterized in larval trematodes. we developed a global proteomic approach to characterize the es proteome of s. mansoni and e. caproni primary spor ... | 2007 | 17606306 |
| ki-67 is expressed in multiplying forms of schistosoma mansoni, but not in snail host tissues. | ki-67 is a protein expressed in the nucleus of several species during cell-division, being absent during the go resting phase of the cellular cycle. during attempts to disclose mitosis in the so-called " amebocyte-producing organ " in biomphalaria glabrata infected with schistosoma mansoni, the parasite multiplying forms appeared strongly marked for ki-67, while the snail tissues were completely negative. these data are worth registering to complement general data on ki-67, and to help future st ... | 2007 | 17710314 |
| characterization of immune genes from the schistosome host snail biomphalaria glabrata that encode peptidoglycan recognition proteins and gram-negative bacteria binding protein. | peptidoglycan (pgn) recognition proteins (pgrps) and gram-negative bacteria binding proteins (gnbps) play an essential role in toll/imd signaling pathways in arthropods. the existence of homologous pathways involving pgrps and gnbps in other major invertebrate phyla such as the mollusca remains unclear. in this paper, we report four full-length pgrp cdnas and one full-length gnbp cdna cloned from the snail biomphalaria glabrata, the intermediate host of the human blood fluke schistosoma mansoni, ... | 2007 | 17805526 |
| surface membrane proteins of biomphalaria glabrata embryonic cells bind fucosyl determinants on the tegumental surface of schistosoma mansoni primary sporocysts. | previous observations that in vitro adherence of biomphalaria glabrata embryonic (bge) cells to sporocyst larval stages of schistosoma mansoni was strongly inhibited by fucoidan, a sulfated polymer of l-fucose, suggested a role for lectinlike bge cell receptors in sporocyst binding interactions. in the present investigation, monoclonal antibodies with specificities to 3 major glycan determinants found on schistosomes, lacdinac, fucosylated lacdinac (ldnf), and the lewis x antigen, were used in a ... | 2007 | 17918362 |
| regulation of hydrogen peroxide release in circulating hemocytes of the planorbid snail biomphalaria glabrata. | biomphalaria spp. serve as obligate intermediate hosts for the human blood fluke schistosoma mansoni. following s. mansoni penetration of biomphalaria glabrata, hemocytes of resistant snails migrate towards the parasite, encasing the larva in a multicellular capsule resulting in its destruction via a cytotoxic reaction. recent studies have revealed the importance of hydrogen peroxide (h(2)o(2)) and nitric oxide (no) in parasite killing [hahn uk, bender rc, bayne cj. killing of schistosoma manson ... | 2008 | 17981329 |
| specific tyrosine phosphorylation induced in schistosoma mansoni miracidia by haemolymph from schistosome susceptible, but not resistant, biomphalaria glabrata. | molecular interplay during snail-schistosome interactions is poorly understood and there is much to discover concerning the effect of snail host molecules on molecular processes in schistosomes. using the biomphalaria glabrata - schistosoma mansoni host-parasite system, the effects of exposure to haemolymph, derived from schistosome-resistant and susceptible snail strains, on protein tyrosine phosphorylation in miracidia have been investigated. western blotting revealed several tyrosine phosphor ... | 2008 | 18053291 |
| molecular determinants of compatibility polymorphism in the biomphalaria glabrata/schistosoma mansoni model: new candidates identified by a global comparative proteomics approach. | the co-evolutionary dynamics that exist in host-parasite interactions sometimes lead to compatibility polymorphisms, the molecular bases of which are rarely investigated. to identify key molecules that are involved in this phenomenon in the schistosoma mansoni/biomphalaria glabrata model, we developed a comparative proteomics approach using the larval stages that interact with the invertebrate host. we used qualitative and quantitative analyses to compare the total proteomes of primary sporocyst ... | 2008 | 18083248 |
| physiological changes and molluscicidal effects of crude latex and milin on biomphalaria glabrata. | euphorbian latex is commonly used as molluscicides and the euphorbia milii latex was reported as most powerful molluscicidal agents. the physiological and lethal effects of the latex components of euphorbia milii, on the intermediate host biomphalaria spp., of the human liver parasite schistosoma mansoni were described in this study. the standard methodologies for testing plant derived molluscicides formulated by world health organisation (who) were followed with some modifications. the young sp ... | 2008 | 18262588 |
| molecular and functional characterization of a tandem-repeat galectin from the freshwater snail biomphalaria glabrata, intermediate host of the human blood fluke schistosoma mansoni. | in the present study, a tandem-repeat type galectin was characterized from an embryonic cell line (bge) and circulating hemocytes of the snail biomphalaria glabrata, intermediate host of the human blood fluke schistosoma mansoni. the predicted b. glabrata galectin (bggal) protein of 32 kda possessed 2 carbohydrate recognition domains, each displaying 6 of 8 conserved amino acids involved in galactoside-binding activity. a recombinant bggal (rbggal) demonstrated hemagglutinating activity against ... | 2008 | 18280060 |
| sublethal effects of ultraviolet b radiation on miracidia and sporocysts of schistosoma mansoni: intramolluscan development, infectivity, and photoreactivation. | schistosoma mansoni occurs in tropical regions where levels of ultraviolet b (uvb; 290-320 nm) light are elevated. however, the effects of uvb on parasite transmission are unknown. this study examines effects of uvb on the miracidia and sporocysts of s. mansoni, focusing specifically on intramolluscan development, infectivity, and the ability to photoreactivate (repair dna damage using visible light). histology revealed that miracidia irradiated with 861 j x m(-2) underwent abnormal development ... | 2007 | 18314673 |
| fibrinogen-bearing protein genes in the snail biomphalaria glabrata: characterization of two novel genes and expression studies during ontogenesis and trematode infection. | all fibrinogen (fbg)-bearing proteins documented to date in the freshwater snail biomphalaria glabrata, the intermediate host of the human blood fluke schistosoma mansoni, possess the same molecular structure; one or two immunoglobin superfamily (igsf) domains at the n-terminus and a fbg domain at the c-terminus (named as fbg-related protein (frep)). here we report two novel genes that encode fbg-bearing proteins from b. glabrata. different from all known freps, the first gene encodes a protein ... | 2008 | 18417215 |
| localization of carbohydrate determinants common to biomphalaria glabrata as well as to sporocysts and miracidia of schistosoma mansoni. | the presence of antigenic carbohydrate epitopes shared by biomphalaria glabrata as well as by the sporocysts and miracidia representing snail-pathogenic larval stages of schistosoma mansoni was assayed by immunohistochemical staining of paraformaldehyde-fixed tissues. to this end, both polyclonal rabbit antiserum raised against soluble egg antigens (sea) of s. mansoni and monoclonal antibodies recognizing the carbohydrate epitopes ldn [galnac(beta1-4)glcnac(beta1-)], f-ldn [fuc(alpha1-3)galnac(b ... | 2008 | 18507884 |
| effects of intermediate host genetic background on parasite transmission dynamics: a case study using schistosoma mansoni. | for parasites that require multiple hosts to complete their development, genetic interplay with one host may impact parasite transmission and establishment in subsequent hosts. in this study, we used microsatellite loci to address whether the genetic background of snail intermediate hosts influences life-history traits and transmission patterns of dioecious trematode parasites in their definitive hosts. we performed experimental schistosoma mansoni infections utilizing two allopatric populations ... | 2008 | 18538767 |
| expression profiling and binding properties of fibrinogen-related proteins (freps), plasma proteins from the schistosome snail host biomphalaria glabrata. | a growing body of evidence suggests an important role for fibrinogen-like proteins in innate immunity in both vertebrates and invertebrates. it has been shown that fibrinogen-related proteins (freps), plasma proteins present in the freshwater snail biomphalaria glabrata, the intermediate host for the human blood fluke schistosoma mansoni, are diverse and involved in snail innate defense responses. to gain further insight into the functions of freps, recombinant frep proteins (rfreps) were produc ... | 2008 | 18562576 |
| comparative orestes-sampling of transcriptomes of immune-challenged biomphalaria glabrata snails. | the snail biomphalaria glabrata (gastropoda, mollusca) is an important intermediate host for the human parasite schistosoma mansoni (digenea, trematoda). anti-pathogen responses of b. glabrata were studied towards a better understanding of snail immunity and host-parasite compatibility. open reading frame ests (orestes) were sampled from different transcriptomes of m line strain b. glabrata, 12h post-challenge with escherichia coli (gram-negative), micrococcus luteus (gram-positive) bacteria or ... | 2008 | 18590737 |
| differences in cysteine protease activity in schistosoma mansoni-resistant and -susceptible biomphalaria glabrata and characterization of the hepatopancreas cathepsin b full-length cdna. | biomphalaria glabrata snails are known to display a wide range of susceptibility phenotypes to schistosoma mansoni infection depending on the genetics of both the snail and the invading parasite. evidence exists for a role of hydrolytic enzymes in the defense of molluscs against invading parasites. to elucidate the role of these enzymes in the outcome of infection in the snail, proteolysis was examined in parasite-resistant and -susceptible snails. zymographs of extracts from the whole snail or ... | 2008 | 18605796 |
| disruption of erk signalling in biomphalaria glabrata defence cells by schistosoma mansoni: implications for parasite survival in the snail host. | biomphalaria glabrata is an intermediate snail host for the human blood fluke schistosoma mansoni. to survive in b. glabrata, s. mansoni must suppress the snail's haemocyte-mediated defence response; the molecular mechanisms by which this is achieved remain largely unknown. we report here that s. mansoni excretory-secretory products (esps) attenuate phosphorylation of extracellular signal-regulated kinase (erk) in haemocytes from a b. glabrata strain susceptible to s. mansoni. whole s. mansoni s ... | 2008 | 18619674 |
| a mathematical model of schistosoma mansoni in biomphalaria glabrata with control strategies. | we describe and analyze a mathematical model for schistosomiasis in which infected snails are distinguished from susceptible through increased mortality and no reproduction. we based the model on the same derivation as anderson and may (j. anim. ecol. 47:219-247, 1978), feng and milner (a new mathematical model of schistosomiasis, mathematical models in medical and health science, nashville, tn, 1997. innov. appl. math., vanderbilt univ. press, nashville, pp. 117-128, 1998), and may and anderson ... | 2008 | 18668296 |
| [temporary and permanent breeding sites for biomphalaria in jaboatão dos guararapes, pe]. | a malacological survey of permanent and temporary breeding sites was conducted in the piedade neighborhood of jaboatão dos guararapes, pernambuco, between november 2006 and november 2007, with the aim of determining the malacological fauna at this locality, along with the potential for schistosomiasis mansoni transmission. in addition to biomphalaria glabrata (say, 1818), the molluscs drepanotrema cimex (moricand, 1837), pomacea sp and melanoides tuberculatus (muller, 1774) were collected. among ... | 2008 | 18719804 |
| wild and domesticated animals as reservoirs of schistosomiasis mansoni in brazil. | natural infection with schistosoma mansoni in wild vertebrates and domesticated animals in brazil is described in this review from an epidemiological viewpoint. some species of wild rodents are small-sized animals, with a short expectation of life, a limited territory, and present high infection rates under natural conditions. a successful maintenance of the parasite's life cycle under artificial conditions can be achieved with biomphalaria glabrata. on the other hand, despite showing low natura ... | 2008 | 18722335 |
| in vitro mitotic responses of the amebocyte-producing organ of biomphalaria glabrata to extracts of schistosoma mansoni. | amebocyte-producing organs (apos) of biomphalaria glabrata were maintained in nonnutritive saline with, or without, extracts of miracidia and adults of schistosoma mansoni, and examined histologically. the hematopoietic cells remained viable and showed measurable mitotic activity for up to 6 days, with little evidence of tissue death. apos accumulated fluid and became swollen by as soon as 24 hr, but no cell exomigration was observed. parasite extracts elicited an increase in the number of divid ... | 2008 | 18973421 |
| controlled chaos of polymorphic mucins in a metazoan parasite (schistosoma mansoni) interacting with its invertebrate host (biomphalaria glabrata). | invertebrates were long thought to possess only a simple, effective and hence non-adaptive defence system against microbial and parasitic attacks. however, recent studies have shown that invertebrate immunity also relies on immune receptors that diversify (e.g. in echinoderms, insects and mollusks (biomphalaria glabrata)). apparently, individual or population-based polymorphism-generating mechanisms exists that permit the survival of invertebrate species exposed to parasites. consequently, the g ... | 2008 | 19002242 |
| simultaneous infection of schistosoma mansoni and s. rodhaini in biomphalaria glabrata: impact on chronobiology and cercarial behaviour. | abstract: | 2008 | 19055722 |
| chemokinetic effect of interleukin-1 beta on cultured biomphalaria glabrata embryonic cells. | previous studies have indicated that a molecule with cytokine activity, possibly an interleukin-1-like (il-1) molecule, plays a role in the killing of larval stages of the blood fluke schistosoma mansoni in the snail host biomphalaria glabrata. the purpose of the present experiment was to test the effects of recombinant-human il-1beta (rhil-1beta) on embryonic b. glabrata (bge) cell motility to determine whether the cells respond to the cytokine. response was measured using a variation of a chem ... | 2009 | 19090650 |
| host-parasite relationship of s. mansoni and b. glabrata. | experiments were conducted to study the host-parasite compatibility of various isolates of biomphalaria glabrata snail and schistosoma mansoni parasite isolates. a series of experiments conducted on 12 s. mansoni isolates have shown a range of infectivity potential for b. glabrata snail and 9 isolates of b. glabrata were found differentially susceptible to infection with s. mansoni trematode parasite. | 2007 | 19093502 |
| biomphalaria glabrata transcriptome: cdna microarray profiling identifies resistant- and susceptible-specific gene expression in haemocytes from snail strains exposed to schistosoma mansoni. | biomphalaria glabrata is an intermediate snail host for schistosoma mansoni, one of the important schistosomes infecting man. b. glabrata/s. mansoni provides a useful model system for investigating the intimate interactions between host and parasite. examining differential gene expression between s. mansoni-exposed schistosome-resistant and susceptible snail lines will identify genes and pathways that may be involved in snail defences. | 2008 | 19114004 |
| flow cytometry analysis of the circulating haemocytes from biomphalaria glabrata and biomphalaria tenagophila following schistosoma mansoni infection. | aiming to further characterize the haemocyte subsets in biomphalaria snails, we have performed a detailed flow cytometric analysis of whole haemolymph cellular components using a multiparametric dual colour labelling procedure. ethidium bromide/acridine orange fluorescence features were used to first select viable haemocytes followed by flow cytometric morphometric analysis based on the laser scatter properties (forward scatter-fsc and side scatter-ssc). our findings demonstrated that b. glabrat ... | 2009 | 19126270 |
| community diversity reduces schistosoma mansoni transmission, host pathology and human infection risk. | global biodiversity loss and disease emergence are two of the most challenging issues confronting science and society. recently, observed linkages between species-loss and vector-borne infections suggest that biodiversity may help reduce pathogenic infections in humans and wildlife, but the mechanisms underlying this relationship and its applicability to a broader range of pathogens have remained speculative. here, we experimentally evaluated the effects of host community structure on transmissi ... | 2009 | 19203926 |
| transcriptome analysis of schistosoma mansoni larval development using serial analysis of gene expression (sage). | summary: infection of the snail, biomphalaria glabrata, by the free-swimming miracidial stage of the human blood fluke, schistosoma mansoni, and its subsequent development to the parasitic sporocyst stage is critical to establishment of viable infections and continued human transmission. we performed a genome-wide expression analysis of the s. mansoni miracidia and developing sporocyst using long serial analysis of gene expression (longsage). five cdna libraries were constructed from miracidia a ... | 2009 | 19265565 |
| behaviour of albino and melanic variants of biomphalaria glabrata say, 1818 (mollusca: planorbidae) following infection by schistosoma mansoni sambon, 1907. | the behaviour of the albino and melanic variants of biomphalaria glabrata of belo horizonte (mg. brazil) was studied comparatively, in terms of their respective susceptibilities to infection by schistosoma mansoni of the same origin, through observation of the elimination of cercariae for a three-month period and the calculation of mortality and infection rates, in control and in infected snails. the number of amoebocytes, granulocytes and hyalinocytes in the circulating hemolymph during differe ... | 2009 | 19347168 |
| effects of host outcrossing on the interaction between an aquatic snail and its locally adapted parasite. | in this study, we investigated the interaction between host outcrossing and infection in the biomphalaria glabrata-schistosoma mansoni system. snails collected from three susceptible isofemale lines were mated with either siblings or snails recently derived from a field site in brazil. resulting inbred and outcrossed progeny were then exposed to s. mansoni larvae and monitored for a 10-week period. interestingly, all snails exhibited equal susceptibility whether they were the result of inbreedin ... | 2009 | 19352708 |
| effects of uvb on interactions between schistosoma mansoni and biomphalaria glabrata. | ultraviolet b (uvb, 280-315nm) radiation is detrimental to both of larvae of the digenetic trematode schistosoma mansoni and its snail intermediate host, biomphalaria glabrata. we explored effects of uvb on three aspects of the interaction between host and parasite: survival of infected snails, innate susceptibility and resistance of snails to infection, and acquired resistance induced by irradiated miracidia. snails infected for 1 week showed significantly lower survival than uninfected snails ... | 2009 | 19375430 |
| nitric oxide production by biomphalaria glabrata haemocytes: effects of schistosoma mansoni esps and regulation through the extracellular signal-regulated kinase pathway. | abstract: | 2009 | 19386102 |
| successful parasitism of vector snail biomphalaria glabrata by the human blood fluke (trematode) schistosoma mansoni: a 2009 assessment. | schistosomiasis, caused by infections by human blood flukes (trematoda), continues to disrupt the lives of over 200,000,000 people in over 70 countries, inflicting misery and precluding the individuals' otherwise reasonable expectations of productive lives. infection requires contact with freshwater in which infected snails (the intermediate hosts of schistosomes) have released cercariae larvae. habitats suitable for the host snails continue to expand as a consequence of water resource developme ... | 2009 | 19393158 |
| schistosomin from the snail biomphalaria glabrata: expression studies suggest no involvement in trematode-mediated castration. | by inhibiting reproductive hormones, the neuropeptide schistosomin produced by the snail lymnaea stagnalis plays an essential role in parasitic castration mediated by the schistosome parasite trichobilharzia ocellata during late stage infection. here we report on the presence and expression of schistosomin in the snail biomphalaria glabrata, a prominent intermediate host of the parasite schistosoma mansoni, one of the causative agents of human schistosomiasis. the deduced amino acid (aa) sequenc ... | 2009 | 19393164 |
| [immunity in parasite-vector snails]. | aquatic snails play a key role in the transmission of parasites such as the human blood or liver flukes (schistosomes and fasciola sp.). during the last decade, particular efforts have been made by a small number of scientists to progress in our understanding of the molecular mechanisms underlying snail immune responses and/or host parasite interactions. complementary approaches using the gastropod snail biomphalaria glabrata, an intermediate host of schistosoma mansoni, have yielded a number of ... | 2009 | 19409193 |
| molecular epidemiology of brazilian biomphalaria: a review of the identification of species and the detection of infected snails. | the three vector species of schistosoma mansoni in brazil, biomphalaria glabrata, b. tenagophila and b. straminea show different susceptibility levels to the trematode besides a wide geographical distribution. the identification of such molluscs is important to further understand the disease epidemiology. considering the fact that morphological identification may become difficult or even impossible under particular circumstances, the use of molecular-based methods have permitted the generation o ... | 2009 | 19426656 |
| activities of naphthoquinones against aedes aegypti (linnaeus, 1762) (diptera: culicidae), vector of dengue and biomphalaria glabrata (say, 1818), intermediate host of schistosoma mansoni. | larvicidal (against aedes aegypti linnaeus, 1762) and molluscicidal (against biomphalaria glabrata say, 1818) activities of several natural and synthetic naphthoquinones were measured, with significant results. the best larvicidal compound is 3-bromojuglone, while the better molluscicides are 2-bromo- and 3-bromo-5-acetoxy-1,4-naphthoquinones together with the 3-bromo-5-methoxy derivative. the present results reinforce the potential use of substituted hydroxyquinones, their salts and halogenated ... | 2009 | 19426662 |
| biomphalaria glabrata peroxiredoxin: effect of schistosoma mansoni infection on differential gene regulation. | to identify gene(s) that may be associated with resistance/susceptibility in the intermediate snail host biomphalaria glabrata to schistosoma mansoni infection, a snail albumen gland cdna library was differentially screened and a partial cdna encoding an antioxidant enzyme thioredoxin peroxidase (tpx), or peroxiredoxin (prx), was identified. the 753bp full-length, single-copy, constitutively expressed gene now referred to as bgprx4 was later isolated. bgprx4 is a 2-cys peroxiredoxin containing t ... | 2009 | 19439374 |
| glycotope analysis in miracidia and primary sporocysts of schistosoma mansoni: differential expression during the miracidium-to-sporocyst transformation. | fucosylated carbohydrate epitopes (glycotopes) expressed by larval and adult schistosomes are thought to modulate the host immune response and possibly mediate parasite evasion in intermediate and definitive hosts. while previous studies showed glycotope expression is developmentally and stage-specifically regulated, relatively little is known regarding their occurrence in miracidia and primary sporocysts. in this study, previously defined monoclonal antibodies were used in confocal laser scanni ... | 2009 | 19545571 |
| schistosoma mansoni infection of juvenile biomphalaria glabrata induces a differential stress response between resistant and susceptible snails. | schistosomes develop successfully in susceptible snails but are encapsulated and killed in resistant ones. mechanism(s) shaping these outcomes involves the parasites ability to evade the snail's defenses. rna analysis from resistant (bs-90), non-susceptible (lac2) and susceptible (nmri) juvenile biomphalaria glabrata to schistosoma mansoni revealed that stress-related genes, heat shock protein 70 (hsp 70) and reverse transcriptase (rt), were dramatically co-induced early in susceptible snails, b ... | 2009 | 19660454 |
| susceptibility to praziquantel of male and female cercariae of praziquantel-resistant and susceptible isolates of schistosoma mansoni. | praziquantel (pzq) is now widely used for the treatment of human schistosomiasis. however, in recent years, there has been a growing concern about the resistance of schistosoma to pzq. the mechanisms of pzq action against schistosoma and resistance of schistosoma to pzq are poorly understood. here, we report differential susceptibilities to pzq between male and female cercariae in the pzq-susceptible and pzq-resistant isolates of schistosoma mansoni, using tail loss as a measurement of pzq actio ... | 2010 | 19765323 |
| identification of immediate response genes dominantly expressed in juvenile resistant and susceptible biomphalaria glabrata snails upon exposure to schistosoma mansoni. | resistance or susceptibility of the snail host biomphalaria glabrata to schistosoma mansoni is determined by the genetics of both the snail and parasite. although mendelian genetics governs adult resistance to infection, juvenile resistance and susceptibility are complex traits. in this study, suppression subtractive hybridization was used to construct forward and reverse cdna libraries to identify genes involved in the immediate response of juvenile resistant (bs-90), non-susceptible (lac2) sna ... | 2010 | 19815034 |
| role of the endogenous antioxidant system in the protection of schistosoma mansoni primary sporocysts against exogenous oxidative stress. | antioxidants produced by the parasite schistosoma mansoni are believed to be involved in the maintenance of cellular redox balance, thus contributing to larval survival in their intermediate snail host, biomphalaria glabrata. here, we focused on specific antioxidant enzymes, including glutathione-s-transferases 26 and 28 (gst26 and 28), glutathione peroxidase (gpx), peroxiredoxin 1 and 2 (prx1 and 2) and cu/zn superoxide dismutase (sod), known to be involved in cellular redox reactions, in an at ... | 2009 | 19924224 |
| differential transcriptomic responses of biomphalaria glabrata (gastropoda, mollusca) to bacteria and metazoan parasites, schistosoma mansoni and echinostoma paraensei (digenea, platyhelminthes). | a 70-mer-oligonucleotide-based microarray (1152 features) that emphasizes stress and immune responses factors was constructed to study transcriptomic responses of the snail biomphalaria glabrata to different immune challenges. in addition to sequences with relevant putative id and gene ontology (go) annotation, the array features non-immune factors and unknown b. glabrata ests for functional gene discovery. the transcription profiles of b. glabrata (3 biological replicates, each a pool of 5 snai ... | 2010 | 19962194 |
| attraction of schistosoma mansoni sambon, 1907 miracidia to biomphalaria glabrata (say, 1818) in the presence of angiostrongylus costaricensis morera and céspedes, 1971 infection. | the attraction exerted by biomphalaria glabrata infected with angiostrongylus costaricensis on schistosoma mansoni miracidia of the bh strain was tested, using a glass apparatus composed by two circular chambers connected to a channel. one mollusk or a sample of a snail conditioning water (scw) was placed in one of the chambers, randomly selected, and the remaining of the apparatus was filled with chlorine-free water. ten miracidia were placed in the centre of the channel and their behaviour was ... | 2009 | 19967180 |
| identification of protein components of egg masses indicates parental investment in immunoprotection of offspring by biomphalaria glabrata (gastropoda, mollusca). | the macromolecules contributed by the freshwater gastropod biomphalaria glabrata, intermediate host of schistosoma mansoni, to developing offspring inside egg masses are poorly known. sds-page fractionated egg mass fluids (emf) of m line and bb02 b. glabrata were analyzed by maldi-tof (ms and tandem ms). a mascot database was assembled with est data from b. glabrata and other molluscs to aid in sequence characterization. of approximately 20 major emf polypeptides, 16 were identified as defense-r ... | 2010 | 19995576 |
| effect of amphotericin b on the infection success of schistosoma mansoni in biomphalaria glabrata. | in the present study, we examined the effect of amphotericin b on larval stages (miracidia and primary sporocyst) of the helminth schistosoma mansoni, the causative agent of human schistosomiasis. amphotericin b (amb) is a polyene macrolide that disturbs the function of the cell membrane; it is widely used as prophylactic antimycotic agent in in vitro culture. we show for the first time that s. mansoni miracidia infectivity is considerably reduced after amb treatment. moreover we demonstrate tha ... | 2010 | 20067790 |
| time series analysis of the transcriptional responses of biomphalaria glabrata throughout the course of intramolluscan development of schistosoma mansoni and echinostoma paraensei. | successful colonization of a compatible snail host by a digenetic trematode miracidium initiates a complex, proliferative development program requiring weeks to reach culmination in the form of production of cercariae which, once started, may persist for the remainder of the life span of the infected snail. how are such proliferative and invasive parasites able to circumvent host defenses and establish chronic infections? using a microarray designed to monitor the internal defense and stress-rel ... | 2010 | 20083115 |
| larval excretory-secretory products from the parasite schistosoma mansoni modulate hsp70 protein expression in defence cells of its snail host, biomphalaria glabrata. | synthesis of heat shock proteins (hsps) following cellular stress is a response shared by many organisms. amongst the hsp family, the approximately 70 kda hsps are the most evolutionarily conserved with intracellular chaperone and extracellular immunoregulatory functions. this study focused on the effects of larval excretory-secretory products (esps) from the parasite schistosoma mansoni on hsp70 protein expression levels in haemocytes (defence cells) from its snail intermediate host biomphalari ... | 2010 | 20182834 |
| effect of crude extract of solanum xanthocarpum against snails and mosquito larvae. | the ethanolic crude extract from solanum xanthocarpum was investigated for its molluscicidal activity against biomphalaria glabrata, the snail vector of schistosoma mansoni, and indoplanorbis exustus, the snail vector of intestinal echinostomiasis and schistosoma spindale, together with the larvicidal activity against the larvae of aedes aegypti, mosquito vector of dengue hemorrhagic fever and culex quinquefasciatus, the mosquito vector of urban bancroftian filariasis. the bioassays were carried ... | 2010 | 20578514 |
| n-glycosylation patterns of hemolymph glycoproteins from biomphalaria glabrata strains expressing different susceptibility to schistosoma mansoni infection. | comparative analyses of the n-glycosylation pattern of hemolymph glycoproteins from biomphalaria glabrata strains puerto rico (bgpr) and salvador (bgbs-90), differing in their susceptibility towards schistosoma mansoni infection, were performed by western blotting, enzyme-linked immunosorbent assays, two-dimensional high-performance liquid chromatography and mass spectrometry. obtained data demonstrated an enhanced expression of serologically cross-reacting, fucosylated carbohydrate epitopes by ... | 2010 | 20599986 |
| genetic differences between strains of biomphalaria glabrata (planorbidae) that are susceptible and unsusceptible to schistosomiasis. | despite the implementation control programs, schistosomiasis continues to spread throughout the world. among modern control strategies, vector control is currently being emphasized. within this context, analysis of the genetic variability of intermediate host snails (biomphalaria spp) is important because it allows identification of specific sequences of the genome of this mollusk related to susceptibility/resistance to schistosoma mansoni infection. we investigated brazilian albino (non-pigment ... | 2010 | 20677134 |
| carbohydrate metabolism alterations in biomphalaria glabrata infected with schistosoma mansoni and exposed to euphorbia splendens var. hislopii latex. | this paper evaluates the alterations in the glycogen content of tissues (digestive gland and cephalopedal mass) and glucose in the haemolymph of biomphalaria glabrata bh strain infected with schistosoma mansoni bh strain and exposed to the latex of euphorbia splendens var. hislopii. a reduction in the glycogen deposits was observed in infected snails exposed and not exposed to latex. however, the exposure to latex caused a greater depletion of the glycogen levels in both sites analysed, especial ... | 2010 | 20721497 |
| the effect of early infection with echinostoma paraensei on the interaction of schistosoma mansoni with biomphalaria glabrata and biomphalaria tenagophila. | infection caused by the trematode echinostoma paraensei has been shown to interfere in the natural resistance to infection by schistosoma mansoni. biomphalaria glabrata is susceptible to infection, while taim isolate biomphalaria tenagophila is resistant to infection by s. mansoni. these two snail species were assessed for infection with e. paraensei two days after exposure to s. mansoni miracidia. the number of b. tenagophila and b. glabrata infected with e. paraensei was lower in co-infected g ... | 2010 | 20721499 |
| phylogenetic analysis of biomphalaria tenagophila (orbigny, 1835) (mollusca: gastropoda). | mitochondrial dna of biomphalaria tenagophila, a mollusc intermediate host of schistosoma mansoni in brazil, was sequenced and characterised. the genome size found for b. tenagophila was 13,722 bp and contained 13 messenger rnas, 22 transfer rnas (trna) and two ribosomal rnas (rrna). in addition to sequencing, the mitochondrial dna (mtdna) genome organization of b. tenagophila was analysed based on its content and localization of both coding and non-coding regions, regions of gene overlap and tr ... | 2010 | 20721500 |
| rural tourism: a risk factor for schistosomiasis transmission in brazil. | this paper reports an outbreak of acute schistosomiasis among 38 tourists who rented a country house in the district of igarapé, the metropolitan region of belo horizonte, brazil, during a holiday period in 2006. a total number of 32 individuals were positive for schistosoma mansoni. results of stool examinations revealed individual s. mansoni egg counts per gram of faeces (epg) ranging from 4-768 epg with a geometric mean egg count of 45. the most frequent clinical symptoms were abdominal pain ... | 2010 | 20721505 |
| factors related to transmission of and infection with schistosoma mansoni in a village in the south-eastern region of brazil. | in this transversal study, factors related to infection with and transmission of schistosoma mansoni were explored. based on stool examinations of two kato-katz smears of a single sample, the prevalences of schistosomiasis and geohelminths were established. in a multivariable analysis, sets of demographic, socio-economic and water contact pattern variables were tested for strength of relation with infection. males presented a 3.39-times higher risk for infection than females. the age groups betw ... | 2010 | 20721510 |
| a large repertoire of parasite epitopes matched by a large repertoire of host immune receptors in an invertebrate host/parasite model. | for many decades, invertebrate immunity was believed to be non-adaptive, poorly specific, relying exclusively on sometimes multiple but germ-line encoded innate receptors and effectors. but recent studies performed in different invertebrate species have shaken this paradigm by providing evidence for various types of somatic adaptations at the level of putative immune receptors leading to an enlarged repertoire of recognition molecules. fibrinogen related proteins (freps) from the mollusc biompha ... | 2010 | 20838648 |
| non-random organization of the biomphalaria glabrata genome in interphase bge cells and the spatial repositioning of activated genes in cells co-cultured with schistosoma mansoni. | biomphalaria glabrata is a major intermediate host for the parasitic trematode schistosoma mansoni, a causative agent of human schistosomiasis. to decipher the molecular basis of this host-parasite interaction, the bge embryonic cell line provides a unique in vitro model system to assess whether interactions between the snail and parasite affect the cell and genome biology in either organism. the organization of the b. glabrata genome in bge cells was studied using image analysis through positio ... | 2011 | 20849859 |
| involvement of the cytokine mif in the snail host immune response to the parasite schistosoma mansoni. | we have identified and characterized a macrophage migration inhibitory factor (mif) family member in the lophotrochozoan invertebrate, biomphalaria glabrata, the snail intermediate host of the human blood fluke schistosoma mansoni. in mammals, mif is a widely expressed pleiotropic cytokine with potent pro-inflammatory properties that controls cell functions such as gene expression, proliferation or apoptosis. here we show that the mif protein from b. glabrata (bgmif) is expressed in circulating ... | 2010 | 20886098 |
| the influence of exposure to euphorbia splendens var. hislopii latex on the concentrations of total proteins and nitrogen products in biomphalaria glabrata infected with schistosoma mansoni. | the aim of this work was to analyze the content of total protein and nitrogen degradation products in biomphalaria glabrata infected with schistosoma mansoni and exposed to euphorbia splendens var. hislopii latex. the lc(50) of this latex was 1.0mg/l. concentrations of uric acid, urea and total proteins were determined in the hemolymph of b. glabrata infected with five s. mansoni miracidia and exposed to a sublethal concentration of e. splendens var. hislopii latex for 24h. the exposure to this ... | 2010 | 21055383 |
| role for a somatically diversified lectin in resistance of an invertebrate to parasite infection. | invertebrates lack adaptive immune systems homologous to those of vertebrates, yet it is becoming increasingly clear that they can produce diversified antigen recognition molecules. we have previously noted that the snail biomphalaria glabrata produces a secreted lectin, fibrinogen-related protein 3 (frep3), unusual among invertebrate defense molecules because it is somatically diversified by gene conversion and point mutation. here we implicate frep3 in playing a central role in resistance to a ... | 2010 | 21084634 |
| an example of molecular co-evolution: reactive oxygen species (ros) and ros scavenger levels in schistosoma mansoni/biomphalaria glabrata interactions. | the co-evolution between hosts and parasites involves huge reciprocal selective pressures on both protagonists. however, relatively few reports have evaluated the impact of these reciprocal pressures on the molecular determinants at the core of the relevant interaction, such as the factors influencing parasitic virulence and host resistance. here, we address this question in a host-parasite model that allows co-evolution to be monitored in the field: the interaction between the mollusc, biomphal ... | 2011 | 21329695 |
| [schistosomiasis prevalence in tutóia village, maranhão, brazil]. | schistosomiasis mansoni is an endemic disease in underdeveloped or developing countries. the study aimed to define schistosomiasis prevalence in bom gosto village, tutóia, maranhão, in 2008 and detect intermediate host occurrence. | 2011 | 21340417 |
| evaluation of the antischistosomal activity of sulfated a-d-glucan from the lichen ramalina celastri free and encapsulated into liposomes. | the antischistosomal activity of the sulfated polysaccharide a-d-glucan (glu.so(4)) extracted from ramalina celastri was evaluated after encapsulation into liposomes (glu.so(4)-lipo) in schistosoma mansoni-infected mice. the effect of treatment with glu.so(4) and glu.so(4)-lipo (10 mg/kg) on egg elimination, worm burden and hepatic granuloma formation was assessed using female albino swiss mice, 35-40 days of age, weighing 25 ± 2 g, infected with 150 cercariae/animal (biomphalaria glabrata, bh s ... | 2011 | 21344137 |
| transmission dynamics of two strains of schistosoma mansoni utilizing novel intermediate and definitive hosts. | the intimate host-parasite relationship mandates adaptation to the genetic and phenotypic variability of their counterparts. here, inbred and outcrossed strains of schistosoma mansoni were challenged with "local" and "novel" intermediate and definitive hosts to examine effects of genetic variability and novelty on infection success and dynamics. genetically distinct lines of biomphalaria glabrata intermediate hosts exposed to inbred and outcrossed s. mansoni larvae were assessed for differences ... | 2011 | 21369763 |
| biomphalaria species in alexandria water channels. | of the several species of biomphalaria snails worldwide that serve as the intermediate host for schistosoma mansoni, biomphalaria alexandrina is a species that is indigenous to egypt. recently, there has been much debate concerning the presence of biomphalaria glabrata and the hybrid of the species with biomphalaria alexandrina. due to this debate, the absence of a clear explanation for the presence of b. glabrata in egyptian water channels and the probability that they may be reintroduced, we c ... | 2011 | 21458594 |
| recombinant functional multidomain hemoglobin from the gastropod biomphalaria glabrata. | the extracellular hemoglobin multimer of the planorbid snail biomphalaria glabrata, intermediate host of the human parasite schistosoma mansoni, is presumed to be a 1.44 mda complex of six 240 kda polypeptide subunits, arranged as three disulfide-bridged dimers. the complete amino acid sequence of two subunit types (bghb1 and bghb2), and the partial sequence of a third type (bghb3) are known. each subunit encompasses 13 paralogus heme domains, and n-terminally a smaller plug domain responsible f ... | 2011 | 21491558 |
| incompatibility between miracidia of schistosoma mansoni and helisoma duryi occurs at two stages: penetration and intramolluscan establishment. | abstract helisoma spp. snails are not susceptible to infection with miracidia of schistosoma mansoni because the miracidia do not penetrate them. however, in view of the phylogenetic proximity and histocompatibility between helisoma and the normal intermediate host, biomphalaria glabrata, schistosome miracidia conceivably could survive if experimentally introduced into the hemocoel of helisoma. to test this hypothesis, schistosome-susceptible nih albino b. glabrata, schistosome-resistant salvado ... | 2011 | 21506822 |
| effect of crude lipopolysaccharide from escherichia coli o127:b8 on the amebocyte-producing organ of biomphalaria glabrata (mollusca). | lipopolysaccharide (lps) is a pathogen associated molecular pattern (pamp) to which the internal defense system (ids) of both vertebrates and invertebrates responds. we measured the mitotic response of the hematopoietic tissue of the schistosome-transmitting snail, biomphalaria glabrata, to crude lps from escherichia coli 0127:b8. in a dose-response study, snails were injected with a range of concentrations of crude lps, and mitotic figures were enumerated in histological sections of amebocyte-p ... | 2011 | 21530581 |
| schistosoma mansoni: a method for inducing resistance to praziquantel using infected biomphalaria glabrata snails. | to elucidate the mechanisms of antischistosoma resistance, drug-resistant schistosoma mansoni laboratory isolates are essential. we developed a new method for inducing resistance to praziquantel (pzq) using successive drug treatments of biomphalaria glabrata snails infected with s. mansoni. infected b. glabrata were treated three times with 100 mg/kg pzq for five consecutive days with a one-week interval between them. after the treatment, the cercariae (le-pzq) produced from these snails and the ... | 2011 | 21537673 |