| trypanosoma rangeli interactions within the vector rhodnius prolixus: a mini review. | this article is an integrative mini review of the research on the interactions between trypanosoma rangeli and the insect vector, rhodnius prolixus. special attention is given to the interactions of these parasites with the gut environment, gut walls, with hemolymph invasion, hemocytes, hemocyte microaggregations, prophenoloxidase-activating system, superoxide, and nitric acid generation and eicosanoid pathways. we described factors affecting vectorial capacity and suggested that t. rangeli may ... | 2005 | 16184237 |
| inhibition of hemocyte microaggregation reactions in rhodnius prolixus larvae orally infected with trypanosoma rangeli. | hemocoelic inoculation of epimastigotes of trypanosoma rangeli strain h14 into 5th-instar larvae of rhodnius prolixus previously fed on blood containing the same parasites, showed reduced number of hemocyte microaggregates in the hemolymph, enhanced number of flagellates in the hemolymph as well as increased mortality of these insects. all these effects were counteracted by combined inoculation of r. prolixus with t. rangeli and arachidonic acid. in vitro assays using hemolymph taken from insect ... | 2004 | 15208035 |
| isolation of serratia marcescens in the midgut of rhodnius prolixus: impact on the establishment of the parasite trypanosoma cruzi in the vector. | the effects of resident bacteria in the stomach of 5th-instar larvae of rhodnius prolixus on the erythrocyte lysis and trypanosoma cruzi infection were studied. the bacteria population increased approximately 10,000-fold after feeding. hemolysis rose to approximately 28% within 24h postfeeding and then linearly grew until day 4 attaining almost 100%. the number of surviving y strain of t. cruzi in the stomach declined drastically, while the infection with dm28c clone was maintained stable. five ... | 2004 | 15208042 |
| trypanosoma rangeli: effects of physalin b on the immune reactions of the infected larvae of rhodnius prolixus. | physalins are seco-steroids obtained from plants of the family solanaceae. herein, we tested physalis angulata l purified physalin b as an immunomodulatory compound in 5th-instar larvae of rhodnius prolixus, which were systemically infected with the h14 trypanosoma rangeli strain protozoan. in uninfected insects, the effective concentration of physalin b, which inhibited 50% of the blood ingested (ed(50)) volume, was 15.2+/-1.6 microg/ml of the meal. ecdysis processes and mortality in uninfected ... | 2006 | 16271717 |
| lignoids in insects: chemical probes for the study of ecdysis, excretion and trypanosoma cruzi-triatomine interactions. | the effects of phytochemicals (lignans and neolignans) are reviewed in a variety of insect species with special focus on the recent advances on feeding, excretion and trypanosoma cruzi interactions with rhodnius prolixus. burchellin, podophyllotoxin, pinoresinol, sesamin, licarin a, and nordihydroguaiaretic acid (ndga) added to the diet of rhodnius prolixus larvae induce antifeedant effects only in doses up to 100 microg/ml of blood meal. additionally, pinoresinol and ndga significantly inhibit ... | 2004 | 15302525 |
| the interplay between patency, microsomal na(+)/k(+) atpase activity and juvenile hormone, in tenebrio molitor parasitized by hymenolepsis diminuta. | beetles infected with metacestodes of the rat tapeworm, hymenolepis diminuta, exhibit reduced fecundity, due to alterations in vitellogenesis. follicle cell patency is retarded and inefficient vitellogenin uptake ensues. here, we have reassessed patency and its stimulation by jh iii at day 3 post-infection, when the most detrimental changes are observed in other ovarian processes. in rhodnius prolixus, patency is believed to be brought about by the action of a jh-dependent membrane-bound na(+)/k ... | 1997 | 12769895 |
| immune responses in rhodnius prolixus: influence of nutrition and ecdysone. | starved larvae of rhodnius prolixus, when challenged with enterobacter cloacae b12, had their mortality related to their period of starvation. r. prolixus larvae fed on plasma alone, compared with insects fed on whole blood, had their immune reactivity affected as shown by: (i) a significant reduction in the ability to produce cecropin-like and lysozyme activities in the haemolymph when inoculated with e. cloacae; (ii) a reduction in numbers of haemocytes and nodule formation following challenge ... | 1997 | 12770413 |
| transformation of rhodococcus rhodnii, a symbiont of the chagas disease vector rhodnius prolixus, with integrative elements of the l1 mycobacteriophage. | elimination of vector populations through the use of insecticides is the principal means of controlling chagas disease. because of the limitations of insecticide use, we have been developing a new potential method of control, to be used in conjunction with insecticide programs, a method which utilizes genetically modified symbiotic bacteria. these transformed bacteria can express anti-parasitic agents in the gut of the bug where the trypanosomes also are found. previous studies have shown that i ... | 2003 | 12809804 |
| analysis of antenal sensilla patterns of rhodnius prolixus from colombia and venezuela. | antennal sensilla patterns were used to analyze population variation of domestic rhodnius prolixus from six departments and states representing three biogeographical regions of colombia and venezuela. discriminant analysis of the patterns of mechanoreceptors and of three types of chemoreceptors on the pedicel and flagellar segments showed clear differentiation between r. prolixus populations east and west of the andean cordillera. the distribution of thick and thin-walled trichoids on the second ... | 2006 | 16444424 |
| pyrethroid-impregnated curtains for chagas' disease control in venezuela. | the use of insecticide treated materials for the control of chagas' disease transmission is potentially a cost-effective and sustainable option where vectors are sylvatic. a study was undertaken in two rural chagas' disease endemic communities (96 households) of trujillo state, venezuela. after a baseline study (including a short questionnaire survey, assessment of housing conditions, vector behaviour and preferences in vector protection), 37 households were chosen at random for protection by im ... | 2003 | 12943974 |
| arthropod transmission of rabbit papillomatosis. | the virus of rabbit papillomatosis, a neoplastic disease studied intensively in relation to cancer because of its tendency toward malignant transformation, has been successfully transmitted by aedes aegypti, rhodnius prolixus, and triatoma infestans from papillomas induced in cottontail rabbits, and by the first species mentioned, from papillomas induced in domestic rabbits. this was accomplished by interrupted feeding, feeding after an interval of several days from the infective meal, or by app ... | 1958 | 13549638 |
| [data on trypanosoma rangeli tejera, 1920, i. technic for obtaining it from the salivary gland of rhodnius prolixus]. | | 1958 | 13586728 |
| synthesis of thiamine and folic acid by nocardia rhodnii, the micro-symbiont of rhodnius prolixus. | | 1960 | 13711570 |
| molecular characterisation of trypanosoma rangeli strains isolated from rhodnius ecuadoriensis in peru, r. colombiensis in colombia and r. pallescens in panama, supports a co-evolutionary association between parasites and vectors. | we present data on the molecular characterisation of strains of trypanosoma rangeli isolated from naturally infected rhodnius ecuadoriensis in peru, from rhodnius colombiensis, rhodnius pallescens and rhodnius prolixus in colombia, and from rhodnius pallescens in panama. strain characterisation involved a duplex pcr with s35/s36/kp1l primers. mini-exon gene analysis was also carried out using trint-1/trint-2 oligonucleotides. kdna and mini-exon amplification indicated dimorphism within both dna ... | 2005 | 15639744 |
| expression of fluorescent genes in trypanosoma cruzi and trypanosoma rangeli (kinetoplastida: trypanosomatidae): its application to parasite-vector biology. | two trypanosoma cruzi-derived cloning vectors, ptrex-n and pbs:calb1/cub01, were used to drive the expression of green fluorescent protein (gfp) and dsred in trypanosoma rangeli tejera, 1920, and trypanosoma cruzi chagas, 1909, isolates, respectively. regardless of the species, group, or strain, parasites harboring the transfected constructs as either episomes or stable chromosomal integrations showed high-level expression of fluorescent proteins. tagged flagellates of both species were used to ... | 2005 | 15691008 |
| effect of blood components, abdominal distension, and ecdysone therapy on the ultrastructural organization of posterior midgut epithelial cells and perimicrovillar membranes in rhodnius prolixus. | the effects of blood components, nerve-cord severance, and ecdysone therapy on the posterior midgut epithelial cells of 5th-instar rhodnius prolixus nymphs 10 days after feeding were analyzed by transmission electron microscopy. cutting the nerve-cord of the blood-fed insects partially reduced the development of microvilli and perimicrovillar membranes (pmm), and produced large vacuoles and small electrondense granules; insects fed on ringer's saline diet exhibited well developed microvilli and ... | 2004 | 15761596 |
| insecticidal effects of canatoxin on the cotton stainer bug dysdercus peruvianus (hemiptera: pyrrhocoridae). | canatoxin (cntx) is a variant form of urease isolated from canavalia ensiformis (leguminosaea) seeds. a possible role in the plant defense was proposed for cntx, due to its toxicity upon feeding to the beetle callosobruchus maculatus, and the hematophagous bug, rhodnius prolixus. the toxic effect is caused by a canatoxin-derived peptide ( approximately 10kda) formed by insect cathepsin-like digestive enzymes. in order to evaluate their potential as bioinsecticides, the effects of cntx and its pe ... | 2005 | 15804524 |
| structural determinants of factor ix(a) binding in nitrophorin 2, a lipocalin inhibitor of the intrinsic coagulation pathway. | nitrophorin 2 (np2) is a salivary lipocalin from rhodnius prolixus that binds with coagulation factors ix (fix) and ixa (fixa). binding of np2 with fixa results in potent inhibition of the intrinsic factor xase complex. a panel of site-directed surface mutants of np2 was generated to locate determinants of high affinity fix(a) binding. the locations of the mutations were based on comparisons with the related, but less potent, inhibitor nitrophorin 3 (np3). three point mutants (k21a, k92a, and v9 ... | 2005 | 15866866 |
| biological effect of 1-dodecanol in teneral and post-teneral rhodnius prolixus and triatoma infestans (hemiptera: reduviidae). | topical application of 1-dodecanol was significantly more toxic against teneral first nymphs (1-3 h old) than post-teneral first nymphs (24 h old). the lethal dose ratios were 711,500 for rhodnius prolixus and 3613 for triatoma infestans. no significative difference between ld50 was found when 1-dodecanol was injected in recently hatched adult r. prolixus (1-4 h old) nor in older adults (24 h old). these values were similar to those calculated for deltamethrin (an effective triatomicide), showin ... | 2005 | 15867966 |
| identifying health centers in honduras infested with rhodnius prolixus using the seroprevalence of chagas disease in children younger than 13 years. | the objective of this study is to determine if a chagas disease protocol starting with a serological survey is as reliable at identifying insect-infested areas as one using the gold standard entomological survey. the study found that health center areas infested with rhodnius prolixus were identified using a threshold seroprevalence of 0.1%. the serological survey took half the time and was 30% less expensive than the entomological survey. developing countries with limited resources may find thi ... | 2005 | 16103595 |
| towards an understanding of the interactions of trypanosoma cruzi and trypanosoma rangeli within the reduviid insect host rhodnius prolixus. | this review outlines aspects on the developmental stages of trypanosoma cruzi and trypanosoma rangeli in the invertebrate host, rhodnius prolixus. special attention is given to the interactions of these parasites with gut and hemolymph molecules and the effects of the organization of midgut epithelial cells on the parasite development. the vector insect's permissiveness to t. cruzi, which develops in the vector gut, largely depends on the host nutritional state, the parasite strain and the molec ... | 2005 | 16127548 |
| could the chagas disease elimination programme in venezuela be compromised by reinvasion of houses by sylvatic rhodnius prolixus bug populations? | the andean pact initiative (1997) committed andean countries to eliminate vectorial transmission of chagas disease by 2010 via widespread residual insecticide spraying. in venezuela, this aim could be compromised by reinvasion of houses by palm tree populations of the major vector rhodnius prolixus. to test this hypothesis, a multivariate logistic regression was undertaken of risk factors for triatomine infestation and colonization in 552 houses and 1068 peri-domestic outbuildings in barinas sta ... | 2006 | 17002733 |
| structural and morphological characterization of hemozoin produced by schistosoma mansoni and rhodnius prolixus. | hemozoin (hz) is a heme crystal produced upon the digestion of hemoglobin (hb) by blood-feeding organisms as a main mechanism of heme disposal. the structure of hz consists of heme dimers bound by reciprocal iron-carboxylate interactions and stabilized by hydrogen bonds. we have recently described heme crystals in the blood fluke, schistosoma mansoni, and in the kissing bug, rhodnius prolixus. here, we characterized the structures and morphologies of the heme crystals from those two organisms an ... | 2005 | 16229843 |
| suppression of the prophenoloxidase system in rhodnius prolixus orally infected with trypanosoma rangeli. | investigations were carried out to compare aspects of the prophenoloxidase (propo)-activating pathway in rhodnius prolixus hemolymph in response to oral infection and inoculation of the insects with two developmental forms of trypanosoma rangeli epimastigotes strain h14. in vivo experiments demonstrated that in control insects fed on uninfected blood, inoculation challenge with short epimastigotes resulted in high phenoloxidase (po) activity. in contrast, previous feeding on blood containing eit ... | 2003 | 16256685 |
| temperature and moisture requirements for conidial germination of an isolate of beauveria bassiana, pathogenic to rhodnius prolixus. | the effects of temperature, relative humidity and water activity on germination of conidia of an isolate of beauveria bassiana (bals.) vuill. pathogenic to the triatomine vector of chagas' disease, rhodnius prolixus stål., were investigated in vitro. germination occurred at temperatures between 15 degrees c and 35 degrees c under saturated atmosphere and the optima ranged from 25 degrees c to 30 degrees c. at the extreme temperatures tested (15 degrees c and 35 degrees c) the germination process ... | 1997 | 16283112 |
| trypanosoma cruzi: effects of infection on cathepsin d activity in the midgut of rhodnius prolixus. | cathepsin d activity was estimated in midgut homogenates from rhodnius prolixus, uninfected and experimentally infected with trypanosoma cruzi, at different times after blood ingestion. no enzyme activity was found in the anterior midgut and rectum. in the posterior midgut, enzyme activity was found both in lumen and wall. in starved uninfected insects, in lumen and wall, cathepsin d activity was high, decreasing to a constant rate at 1-15 days after feeding. in insects infected with t. cruzi ca ... | 2006 | 16288741 |
| mortality profiles of rhodnius prolixus (heteroptera: reduviidae), vector of chagas disease. | life table data of rhodnius prolixus (heteroptera: reduviidae) kept at laboratory conditions were analysed in search for mortality patterns. gompertz and weibull mortality models seem adequate to explain the sigmoid shape of the survivorship curve. a significant fit was obtained with both models for females (r(2) = 0.70, p < 0.0005 for the gompertz model; r(2) = 0.78, p < 0.0005 for the weibull model) and for males (r(2) = 0.39, p < 0.0005 for the gompertz model; r(2) = 0.48, p < 0.0005 for the ... | 2004 | 15350863 |
| chlorinated tyrosine derivatives in insect cuticle. | a method for quantitative measurement of 3-monochlorotyrosine and 3,5-dichlorotyrosine in insect cuticles is described, and it is used for determination of their distribution in various cuticular regions in nymphs and adults of the desert locust, schistocerca gregaria. the two chlorinated tyrosine derivatives were present in all analyzed regions in mature adult locusts, the highest concentrations were found in the sclerotized cuticle of femur and tibia, but significant amounts were also present ... | 2004 | 15475302 |
| phagocytosis of latex beads and bacteria by hemocytes of the triatomine bug rhodnius prolixus (hemiptera: reduvidae). | insect circulating hemocytes are primarily responsible for the immune defense against parasites and pathogens. here, we have analyzed phagocytosis of both biotic (bacteria) and abiotic (latex) particles by circulating hemocytes of 5th-instar nymphs of the triatomine bug rhodnius prolixus. the following hemocyte types were identified: prohemocytes, plasmatocytes, granulocytes, oenocytoids and adipohemocytes. there was a considerable change in the relative percentage of plasmatocytes and prohemocy ... | 2008 | 17368036 |
| mixed domestic infestation by rhodnius prolixus stal, 1859 and panstrongylus geniculatus latreille, 1811, vector incrimination, and seroprevalence for trypanosoma cruzi among inhabitants in el guamito, lara state, venezuela. | mixed infestation of nymphs and adults of rhodnius prolixus stal, 1859 and panstrongylus geniculatus latreille, 1811 was detected in 3 (15%) of 20 dwellings in el guamito, an endemic focus of chagas disease in lara state, venezuela. in one of the houses, both species were positive for trypanosoma cruzi: 14.3% (r. prolixus) and 20% (p. geniculatus ). the overall infection rate in 143 of 352 r. prolixus was 16.1%. parasites isolated from r. prolixus were identified as t. cruzi i by random amplifie ... | 2004 | 15516649 |
| trypanosoma rangeli: characterization of a mg-dependent ecto atp-diphosphohydrolase activity. | in this work we describe the ability of living trypanosoma rangeli to hydrolyze extracellular atp. in these intact parasites whose viability was assessed before and after the reactions by motility and by trypan blue dye exclusion, there was a low level of atp hydrolysis in the absence of any divalent metal (1.53+/-0.12 nmol p(i)/h x 10(7) cells). the atp hydrolysis was stimulated by mgcl(2) and the mg-dependent ecto-atpase activity was 5.24+/-0.64 nmol p(i)/h x 10(7) cells. the mg-dependent ecto ... | 2006 | 16289087 |
| acid phosphatase activity distribution in salivary glands of triatomines (heteroptera, reduviidae, triatominae). | acid phosphatase activity (gömori technique) in salivary gland cells was investigated in adult insects (males and females) of four species of triatomines: triatoma infestans, panstrongylus megistus, rhodnius neglectus, and rhodnius prolixus. binucleated cells with bulky and polyploidy nuclei were detected, with acid phosphatase activity in the heterochromatin and nucleolus, which showed the most intense response. thus, the activity of these phosphatases during rrna molecule transcription, possib ... | 2007 | 17469069 |
| [triatomines (reduviidae: triatominae) in a chagas disease focus in talaigua nuevo (bolívar, colombia)]. | the epidemiological importance and ecological characteristics of triatomines were investigated in a chagas disease focus in talaigua nuevo, bolivar province. | 2005 | 16433183 |
| take-off activity and orientation of triatomines (heteroptera: reduviidae) in relation to the presence of artificial lights. | we analysed the flying activity of triatoma infestans and rhodnius prolixus when confronted to artificial lights of different spectral quality. we found that the presence of light sources (white or ultraviolet) did not affect their spontaneous take-off rate. the comparison between species showed that r. prolixus was more prone to fly than t. infestans. females of t. infestans initiated flight more frequently than males of the same species. although the same tendency was observed in r. prolixus, ... | 2006 | 16460653 |
| parasitogenic alterations of vector behaviour. | in many parasite-vector systems, alterations of the behaviour of the blood-sucking arthropods result in an increase of the transmission rate, but the underlying mechanisms are elucidated in only some systems. the more sluggish movements of the trypanosoma rangeli-infected triatomine rhodnius prolixus might increase the rate of predation by insectivorous mammals but also the transmission rate between the triatomines via cannibalism. alterations of the feeding behaviour by which the number of atta ... | 2006 | 16530007 |
| salivation pattern of rhodnius prolixus (reduviidae; triatominae) in mouse skin. | the objective of this work was to study the pattern of salivation of triatomines during feeding in mouse skin. rhodnius prolixus was fed with a solution of the dye acridine orange or fluorescein. the saliva was efficiently labelled with acridine orange, probably due to the difference in ph between the salivary gland (6.0) and the hemolymph (6.5-7.0). this procedure was not effective at labelling the saliva of triatoma infestans, however, fluorescent labelling of r. prolixus saliva allowed us to ... | 2006 | 16580013 |
| a multiplex pcr assay that separates rhodnius prolixus from members of the rhodnius robustus cryptic species complex (hemiptera: reduviidae). | rhodnius prolixus is one of the most important primary vectors of human chagas disease in latin america. its morphology is, however, identical to that of the members of the rhodnius robustus cryptic species complex, which includes secondary vectors. the correct identification of these taxa with differential vector competence is, therefore, of great epidemiological relevance. we used the alignment of 26 mitochondrial cytochrome b haplotypes (663 bp) to select for pcr-amplifiable species-specific ... | 2007 | 17550472 |
| sulfated glycosaminoglycans in two hematophagous arthropod vectors of chagas disease, triatoma brasiliensis and rhodnius prolixus (hemiptera: reduviidae). | the characterization of sulfated glycosaminoglycans (gags) in hematophagous arthropod vectors in general has been limited, with the exception of the studies in the triatomine rhodnius prolixus. heparan sulfate (hs) and chondroitin sulfate (cs) were previously identified and structurally characterized in extracts of whole bodies of fourth instar larvae of r. prolixus. recently, we showed the expression of these two sulfated gags in specific body tissues of adult males and females and in embryos o ... | 2004 | 15581795 |
| nitric oxide interaction with insect nitrophorins and thoughts on the electron configuration of the {feno}6 complex. | the nitrophorins are no-carrying heme proteins that are found in the saliva of two species of blood-sucking insects, the kissing bug (rhodnius prolixus) and the bedbug (cimex lectularius). in both insects the no is bound to the ferric form of the protein, which gives rise to kds in the micromolar to nanomolar range, and thus upon injection of the saliva into the tissues of the victim the no can dissociate to cause vasodilation and inhibition of platelet aggregation. the structures of the protein ... | 2005 | 15598503 |
| heme-assisted s-nitrosation of a proximal thiolate in a nitric oxide transport protein. | certain bloodsucking insects deliver nitric oxide (no) while feeding, to induce vasodilation and inhibit blood coagulation. we have expressed, characterized, and determined the crystal structure of the cimex lectularius (bedbug) nitrophorin, the protein responsible for no storage and delivery, to understand how the insect successfully handles this reactive molecule. surprisingly, no binds not only to the ferric nitrophorin heme, but it can also be stored as an s-nitroso (sno) conjugate of the pr ... | 2005 | 15637157 |
| antiserum against perimicrovillar membranes and midgut tissue reduces the development of trypanosoma cruzi in the insect vector, rhodnius prolixus. | antiserum raised against rhodnius prolixus perimicrovillar membranes (pmm) and midgut tissue interfered with the midgut structural organization and reduced the development of trypanosoma cruzi in the r. prolixus insect vector. sds-page and western blot analyses confirmed the specific recognition of midgut proteins by the antibody. feeding, mortality, molt, and oviposition of the insects were unaffected by feeding with the antiserum. however, the eclosion of the eggs were reduced from r. prolixus ... | 2006 | 16759654 |
| cellular immune response in rhodnius prolixus: role of ecdysone in hemocyte phagocytosis. | in this paper we investigate in vivo and in vitro effects of orally administered azadirachtin and ecdysone on the phagocytic responses of rhodnius prolixus 5th-instar larval hemocytes to the yeast saccharomyces cerevisiae. groups of insects fed non-treated blood (control) and insects that received azadirachtin plus ecdysone in the blood meal were inoculated with yeast cells in the hemocele. the injected yeast cells disappeared rapidly from the hemolymph, being removed completely by 90min after i ... | 2006 | 16759667 |
| web 2086, a platelet-activating factor antagonist, inhibits prophenoloxidase-activating system and hemocyte microaggregation reactions induced by trypanosoma rangeli infection in rhodnius prolixus hemolymph. | the effects of the triazolodiazepine web 2086, a platelet-activating factor (paf) antagonist, on hemocyte microaggregation and prophenoloxidase (propo)-activating system in the hemolymph, hemocoelic infection and mortality in fifth-instar larvae of rhodnius prolixus inoculated with trypanosoma rangeli were investigated. hemocoelic injection of short t. rangeli epimastigotes (1x10(4) parasites/insect) in r. prolixus that were previously fed with blood containing 1mum of web 2086 resulted in (i) r ... | 2006 | 16777137 |
| taxonomic study of the phyllosoma complex and other triatomine (insecta: hemiptera: reduviidae) species of epidemiological importance in the transmission of chagas disease: using its-2 and mtcytb sequences. | the purpose of this work was to clarify the taxonomy and phylogenetic relationship of the phyllosoma complex and other important vectors in mexico. the internal transcribed spacer 2 (its-2) of rdna and the cytochrome b gene of mtdna (mtcytb) were analyzed for the following species of triatomine: triatoma bassolsae, t. longipennis, t. mazzottii, t. mexicana, t. pallidipennis, t. picturata, and t. phyllosoma belonging to the phyllosoma complex, as well as t. dimidiata, t. rubida, t. infestans, and ... | 2006 | 16815044 |
| rhodnius prolixus: identification of immune-related genes up-regulated in response to pathogens and parasites using suppressive subtractive hybridization. | we report the identification of immune-related molecules from the fat body, and intestine of rhodnius prolixus, an important vector of chagas disease. insects were challenged by introducing pathogens or trypanosoma cruzi, the parasite that causes chagas disease, into the hemocoel. rna from intestines, or fat body were isolated 24h after stimulation. we used suppressive subtractive hybridization to identify immune-related genes, generated three subtracted libraries, sequenced the clones and assem ... | 2007 | 16824597 |
| a micro-spreading improvement for spermatogenic chromosomes from triatominae (hemiptera-reduviidae). | cytogenetics of triatomines have been a valuable biological tool for the study of evolution, taxonomy, and epidemiology of these vectors of trypanosoma cruzi. here we present a single microtube protocol that combines micro-centrifugation and micro-spreading, allowing high quality cytogenetic preparations from male gonadal material of rhodnius prolixus and triatoma lecticularia. the amount of cellular scattering can be modulated, which can be useful if small aggregates of synchronous cells are de ... | 2006 | 16862334 |
| rna interference of the salivary gland nitrophorin 2 in the triatomine bug rhodnius prolixus (hemiptera: reduviidae) by dsrna ingestion or injection. | mass sequencing of cdna libraries from salivary glands of triatomines has resulted in the identification of many novel genes of unknown function. the aim of the present work was to develop a functional rna interference (rnai) technique for rhodnius prolixus, which could be widely used for functional genomics studies in triatomine bugs. to this end, we investigated whether double-stranded rna (dsrna) can inhibit gene expression of r. prolixus salivary nitrophorin 2 (np2) and what impact this migh ... | 2006 | 16935217 |
| exploring the role of insect host factors in the dynamics of trypanosoma cruzi-rhodnius prolixus interactions. | members of the subfamily triatominae, family reduviidae, comprise a large number of insect species of which some are vectors of trypanosoma cruzi, the causative agent of chagas' disease. this article outlines research on the process of transformation and the dynamics of developmental stages of trypanosoma cruzi in the triatomine insect hosts. special attention is given to the interactions of parasites with gut molecules, and the gut environment, and with host developmental physiology and intesti ... | 2007 | 17141801 |
| [population structure and genetic variability of rhodnius prolixus (hemiptera: reduviidae) from different geographic areas of colombia]. | rhodnius prolixus is the most important vector of chagas disease in colombia. genetic characterization of this species is useful to understand its potential of dispersion. the distribution of the vector and the genetic population structure are important factors for the adequate implementation of control programs and epidemiological surveillance of chagas disease. | 2007 | 18154243 |
| [comparison of feeding and defecation patterns of rhodnius colombiensis and rhodnius prolixus(hempitera, reduviidae, triatominae) under laboratory conditions]. | rhodnius colombiensis occasionally comes into human dwellings and consequently its role as an important potential vector in the transmission of american trypanosomiasis has been suggested. | 2007 | 18154250 |
| trypanosoma cruzi: attachment to perimicrovillar membrane glycoproteins of rhodnius prolixus. | studies were carried out to identify proteins involved in the interface of trypanosoma cruzi with the perimicrovillar membranes (pmm) of rhodnius prolixus. video microscopy experiments demonstrated high level of adhesion of t. cruzi dm 28c epimastigotes to the surface of posterior midgut cells of non-treated r. prolixus. the parasites however were unable to attach to gut cells obtained from decapitated or azadirachtin-treated insects. the influence of carbohydrates on the adhesion to insect midg ... | 2007 | 17250827 |
| replication of flock house virus in three genera of medically important insects. | flock house virus (family nodaviridae, genus alphanodavirus, fhv) was originally isolated from grass grubs costelytra zealandica (white) (coleoptera: scarabaeidae) in new zealand and belongs to a family of divided genome, plus-sense rna insect viruses. fhv replicates in insects, a nematode, plants, and yeast. we previously reported replication of fhv in four genera of mosquitoes and expression of green fluorescent protein in aedes aegypti (l.) produced by an fhv-based vector. we report here that ... | 2007 | 17294927 |
| morphometric evidence for a possible role of rhodnius prolixus from palm trees in house re-infestation in the state of barinas (venezuela). | the main vector of chagas disease in venezuela is rhodnius prolixus. specimens of rhodnius sp., identified elsewhere as r. prolixus by molecular tools, were collected in barinas state (venezuela) before insecticide application, and compared by morphometric techniques with post-spraying, re-infesting insects after control. geometric morphometry was applied, allowing separate analyses of shape and size. the idea of a single species sharing silvatic and domestic/peri-domestic ecotopes was supported ... | 2007 | 17306204 |
| trypanosoma cruzi: involvement of glycoinositolphospholipids in the attachment to the luminal midgut surface of rhodnius prolixus. | trypanosoma cruzi epimastigotes adhere in vivo to the luminal surface of their triatomid vector digestive tract by molecular mechanisms, as yet, unknown. here, we show that the administration of 0.5 microm epimastigote major surface glycoinositolphospholipids (gipls) to the infected bloodmeal inhibits up to 90% parasite infection in rhodnius prolixus. the parasite behavior was investigated in vitro using fragments of the insect midgut. the addition of gipls in concentration as low as 50-100 nm i ... | 2007 | 17306256 |
| [defecation index and reproductive success of triatoma maculata (hemiptera: reduviidae) under laboratory conditions]. | the reproductive and defecating behavior of triatoma maculata (erichson 1848) was studied on animals from an university culture in venezuela. this species does not reach the importance of rhodnius prolixus stal 1859 as chagas disease vector in venezuela. this study addressed the role of defecating frequency, an index of how dangerous the animals are for the human population, and its relationship with why t. maculata is a less important vector than r. prolixus. human blood was fed to the insects ... | 2004 | 17354403 |
| identification and characterization of two novel lysozymes from rhodnius prolixus, a vector of chagas disease. | lysozymes have been described in invertebrates as digestive or immune molecules. we report here the characterization of two novel c-type lysozymes, rplys-a (eu250274) and rplys-b (eu250275), isolated from the fat body and digestive tract of immune stimulated rhodnius prolixus, a major vector of chagas disease. transcriptional profiles indicate that the temporal and spatial expression patterns of these two peptides are very different. rplys-a is expressed predominantly in the midgut after ingesti ... | 2008 | 18258253 |
| overexpression in escherichia coli and functional reconstitution of the liposome binding ferriheme protein nitrophorin 7 from the bloodsucking bug rhodnius prolixus. | a number of ferriheme proteins, termed nitrophorins (nps), occur in the saliva of the bloodsucking insect rhodnius prolixus ('kissing bug'), which is a vector for chagas' disease. nitrophorins bind the heme b cofactor in the beta-barrel of their lipocalin fold, which is further anchored through a proximal histidine-fe(iii) bond. the distal fe(iii) coordination site then binds nitric oxide (no) for delivery into a host's tissues during blood feeding, where, upon no release, the distal fe(iii) sit ... | 2007 | 17428677 |
| differential modulation of rhodnius prolixus nitric oxide activities following challenge with trypanosoma rangeli, t. cruzi and bacterial cell wall components. | nitric oxide (no) is a key immune effector and signaling molecule in many organisms. however, the contribution no makes towards insect immunity has received little attention, particularly in non-dipteran species. in this study, tissue- and time-specific alterations in no synthase (nos) gene expression and no production were documented in the hemipteran vector of chagas' disease, rhodnius prolixus, following in vivo immune challenge by trypanosoma cruzi, t. rangeli and crude bacterial lipopolysac ... | 2007 | 17456439 |
| [epidemiology of chagas disease in andrés eloy blanco, lara, venezuela: triatomine infestation and human seroprevalence]. | a seroepidemiological survey and vector captures were performed in four rural communities in andrés eloy blanco, lara state, venezuela. systematic random sampling was based on family clusters, with samples drawn from 869 individuals to determine anti-trypanosoma cruzi and anti-leishmania sp. antibodies by indirect immunofluorescence. positive individuals were defined as > or = 1:32 for anti-t. cruzi antibody and non-reactive to leishmania sp. antigen, revealing an antibody frequency of 6.9% (n = ... | 2007 | 17486235 |
| risk factors for trypanosoma cruzi human infection in barinas state, venezuela. | this study attempted to quantify the transmission of trypanosoma cruzi in children less than 15 years of age in barinas state, venezuela and investigate risk factors for infection. among 3,296 children, 4 (0.12%) were seropositive. the mother of one child also was also seropositive, which suggested that congenital transmission is a possible risk factor for chagas disease in this area. seroprevalence among the dwellers of 10 localities was 3.3%. rhodnius prolixus was detected in 7 localities and ... | 2007 | 17488916 |
| lipid metabolism in rhodnius prolixus (hemiptera: reduviidae): role of a midgut triacylglycerol-lipase. | the utilization of dietary lipids was studied in adult females of rhodnius prolixus with the use of radiolabeled triacylglycerol (tag). it was shown that (3)h-triolein, when added to blood meal, was hydrolyzed to free fatty acids in the posterior midgut lumen. subsequently, free fatty acids were absorbed by posterior midgut epithelium and used in the synthesis of phospholipids, diacylglycerol (dag) and tag. phospholipids, dag and free fatty acids were then found in hemolymph, from where they wer ... | 2007 | 17517335 |
| effect of ectoparasitic pimeliaphilus plumifer mites (acari: pterygosomatidae) on meccus pallidipennis (hemiptera: reduviidae) and several other chagas' disease vectors under laboratory conditions. | several biological parameters were evaluated to determine the capacity of pimeliaphilus plumifer as biological control agent of triatominae bugs. when p. plumifer and bugs of a variety of triatomine species were forced together in cages in the laboratory, the incidence of mite infestation was the following: meccus pallidipennis > m. bassolsae > triatoma rubida > m. longipennis > m. picturatus, and practically no mites were found on t. infestans and rhodnius prolixus. adults and hexapod larvae of ... | 2007 | 17549587 |
| trypanosoma cruzi: ultrastructural studies of adhesion, lysis and biofilm formation by serratia marcescens. | a few days after blood meal the number of bacteria in the anterior midgut (stomach) of rhodnius prolixus, a vector of trypanosoma cruzi, the causative agent of chagas' disease, increases dramatically. many of the bloodstream trypomastigotes of the pathogenic protozoan as well as ingested erythrocytes are lysed in the stomach. incubation of t. cruzi with serratia marcescens variant sm365, lead to parasite lysis. in the present study, this bacterium rapidly adhered to the protozoan surface through ... | 2007 | 17570364 |
| apo-nitrophorin 4 at atomic resolution. | the nitrophorins from rhodnius prolixus, the kissing bug, are heme-containing proteins used for the transport of nitric oxide to aide the insect in obtaining a blood meal. the rhodnius nitrophorins display an eight-stranded antiparallel beta-barrel motif, typical of lipocalins, with a histidine-linked heme in the open end of the barrel. heme is stabilized in the ferric state and highly distorted, displaying a ruffled conformation that may be of importance in the setting of the reduction potentia ... | 2007 | 17660249 |
| trypanosoma cruzi: experimental parasitism of bone and cartilage. | trypanosoma cruzi causes chagas' disease, a systemic infection that affects cells of meso-, endo-, and ectodermic origin. however, as far as we know, the presence of t. cruzi stages in bone has not been reported previously, and it has scarcely been investigated in cartilage. we inoculated 7- and 20-day-old (8 and 15 g) nmri albino mice i.p. with metacyclic trypomastigotes from rhodnius prolixus used for xenodiagnosis of mice previously infected with mammalian, human, and triatomines isolates, ch ... | 2006 | 16721600 |
| control of chagas disease. | the southern cone initiative (iniciativa de salud del cono sur, incosur) to control domestic transmission of trypanosoma cruzi is a substantial achievement based on the enthusiasm of the scientific community, effective strategies, leadership, and cost-effectiveness. incosur triggered the launch of other regional initiatives in central america and in the andean and amazon regions, which have all made progress. the central american initiative targeted the elimination of an imported triatomine bug ... | 2006 | 16735164 |
| expression of gp82 and gp90 surface glycoprotein genes of trypanosoma cruzi during in vivo metacyclogenesis in the insect vector rhodnius prolixus. | trypanosoma cruzi, the parasite causing chagas' disease, relies on triatomines for its transmission. t. cruzi metacyclic trypomastigotes express gp82 and gp90, which are developmentally regulated surface proteins that have been implicated in host cell invasion. we used quantitative rt-pcr to quantify gp90 and gp82 mrna levels expressed by t. cruzi in the digestive tract of experimentally infected rhodnius prolixus at different times post infection. translation of these transcripts was assessed b ... | 2008 | 17889817 |
| environmental determinants of the distribution of chagas disease vectors in south-eastern guatemala. | the associations between the presence of triatomines and environmental variables were studied using correlation analysis and logistic regression models for a sample of villages in the south-eastern provinces of guatemala. information on the presence of triatoma dimidiata, t. nitida and rhodnius prolixus came from entomological surveys carried out by the ministry of health of guatemala as part of its vector control programme. environmental information for each village was extracted from digital t ... | 2007 | 18686245 |
| chagas disease in andean countries. | the andean countries' initiative (aci) for controlling chagas disease was officially created in 1997 within the framework of the hipolito unanue agreement (unanue) between the ministries of health of colombia, ecuador, peru, and venezuela. its objective was to interrupt transmission via vector and transfusion in the region, taking into account that there are 12.5 million people at risk in the four andean countries forming the initiative in the area and around 3 million people are infected by try ... | 2007 | 17891273 |
| do haematophagous bugs assess skin surface temperature to detect blood vessels? | it is known that some blood-sucking insects have the ability to reach vessels under the host skin with their mouthparts to feed blood from inside them. however, the process by which they locate these vessels remains largely unknown. less than 5% of the skin is occupied by blood vessels and thus, it is not likely that insects rely on a "random search strategy", since it would increase the probability of being killed by their hosts. indeed, heterogeneities along the skin surface might offer exploi ... | 2007 | 17895973 |
| biological characterization of trypanosoma cruzi stocks from domestic and sylvatic vectors in sierra nevada of santa marta, colombia. | sierra nevada of santa marta is one of the most endemic regions of chagas disease in colombia. in this study, we compared the biological behavior and genetic features of trypanosoma cruzi stocks that were isolated from domestic and sylvatic insects in this area. rhodnius prolixus (from domestic environments) and triatoma dimidiata (from sylvatic, peridomestic and domestic environments) are the most important vectors in this region. genetic characterization showed that all stocks corresponded to ... | 2008 | 18804443 |
| biochemical properties of the major proteins from rhodnius prolixus eggshell. | two proteins from the eggshell of rhodnius prolixus were isolated, characterized and named rp30 and rp45 according to their molecular masses. purified proteins were used to obtain specific antiserum which was later used for immunolocalization. the antiserum against rp30 and rp45 detected their presence inside the follicle cells, their secretion and their association with oocyte microvilli. both proteins are expressed during the final stage of vitellogenesis, preserved during embryogenesis and di ... | 2007 | 17916507 |
| blockades of phospholipase a(2) and platelet-activating factor receptors reduce the hemocyte phagocytosis in rhodnius prolixus: in vitro experiments. | the hemocytes phagocytosis in response to microorganisms may play an important role in the cellular immune responses of insects. here, we have evaluated the effects of the platelet-activating factor (paf) and eicosanoids in the phagocytosis of hemocyte monolayers of rhodnius prolixus to the yeast saccharomyces cerevisiae. experiments showed that the phagocytosis of yeast cells by rhodnius hemocytes is very efficient in both controls and cells treated with paf and arachidonic acid. phagocytosis o ... | 2008 | 18036540 |
| haemozoin formation. | formation of malaria pigment or haemozoin is the major route of haem detoxification in the malaria parasite plasmodium falciparum as well as several other species of haematophagous organisms, including other plasmodium species, helminth worms such as schistosoma mansoni and blood-sucking insects such as rhodnius prolixus. recent advances in our understanding of the formation of haemozoin, both from new observations that it is formed within lipid bodies in p. falciparum and s. mansoni and biomime ... | 2008 | 18083247 |
| differential actions of diuretic factors on the malpighian tubules of rhodnius prolixus. | the effects of corticotropin-releasing factor (crf)-related (zoonedh), calcitonin (ct)-related (rhoprdh(31)) and kinin-related (leucokinin i) peptides on the ion composition of fluid secreted by upper rhodnius prolixus malpighian tubules and on kcl reabsorption by the lower tubules were assessed. zoonedh stimulated fluid secretion while increasing the [na(+)] of secreted fluid at the expense of [k(+)]. upper tubules responded to zoonedh with a characteristic triphasic change in the transepitheli ... | 2008 | 18083731 |
| [updated geographical distribution and ecoepidemiology of the triatomine fauna (reduviidae: triatominae) in colombia]. | information concerning triatomine records from provinces and municipalities was accumulated-including data indicating natural infections with trypanosomatides-that has been previously published or reported by colombian provincial health services and research institutes. altitude appeared to be the main factor responsible for the distribution of the insects. illustrations summarize the information provided by the above records. a triatomine fauna classification is presented that corresponds to th ... | 2007 | 18154255 |
| comparative peptidomics of four related hemipteran species: pyrokinins, myosuppressin, corazonin, adipokinetic hormone, snpf, and periviscerokinins. | we performed the first comprehensive peptidomic analysis of neurohormones from hemipteran insects by analyzing the neuropeptides of two major neurohemal organs, namely the corpora cardiaca and abdominal perisympathetic organs. for the experiments we selected four related species of polyphagous stinkbugs (pentatomidae), three of which are known to attack several important food crops. peptide sequences were identified by maldi-tof mass spectrometry; tandem fragmentation of myosuppressin, snpf, cap ... | 2008 | 18201800 |
| a panel of ten microsatellite loci for the chagas disease vector rhodnius prolixus (hemiptera: reduviidae). | rhodnius prolixus is the main vector of chagas disease in venezuela, where it is found colonising rural housing consisting of unplastered adobe walls with palm and/or metal roofs. vector control failure in venezuela may be due to the invasion of houses by silvatic populations of r. prolixus found in palms. as part of a study to determine if domestic and silvatic populations of r. prolixus are isolated, thus clarifying the role of silvatic populations in maintaining house infestations, we constru ... | 2009 | 19061974 |
| [using elisa for identifying triatominae feeding behaviour in colombia]. | standardising the elisa technique for identifying triatomine insects' feeding behaviour. | 2007 | 18209827 |
| recent advances in understanding the mechanism of hemozoin (malaria pigment) formation. | the recent literature on hemozoin/beta-hematin formation is reviewed, with an emphasis on the mechanism of its formation. recent findings from unrelated organisms that produce hemozoin, namely the malaria parasite plasmodium falciparum, the worm schistosoma mansoni and the kissing bug rhodnius prolixus all of which consume human hemoglobin show that the formation of this crystalline substance occurs within or at the surface of lipids. biomimetic experimental models of the lipid-water interface a ... | 2008 | 18226838 |
| immune depression in rhodnius prolixus by seco-steroids, physalins. | a comparative study of the effects of physalins, seco-steroidal substances of physalis angulata (solanaceae), on the immune reactions of r. prolixus was carried out. ecdysis and mortality were not affected by treatment with physalins b, d, f or g (1-10 microg/ml of blood meal). r. prolixus larvae fed with blood containing physalins and inoculated with 1 microl of enterobacter cloacae beta12 (5 x 10(3)/insect) exhibited mortality rates three times higher than controls. the insects treated with ph ... | 2008 | 18234209 |
| genomic resources for invertebrate vectors of human pathogens, and the role of vectorbase. | high-throughput genome sequencing techniques have now reached vector biology with an emphasis on those species that are vectors of human pathogens. the first mosquito to be sequenced was anopheles gambiae, the vector for plasmodium parasites that cause malaria. further mosquitoes have followed: aedes aegypti (yellow fever and dengue fever vector) and culex pipiens (lymphatic filariasis and west nile fever). species that are currently in sequencing include the body louse pediculus humanus (typhus ... | 2009 | 18262474 |
| microsatellite markers from the chagas disease vector, rhodnius prolixus (hemiptera, reduviidae), and their applicability to rhodnius species. | ten microsatellites were isolated and characterized from a partial genomic library of rhodnius prolixus, the principal chagas disease vector in venezuela, colombia and central america. these polymorphic molecular markers could be particularly useful in chagas disease control initiatives. a wider applicability of the primer-pairs isolated was shown, from 6 to 10 loci being amplifiable in five out of the ten rhodnius species tested, namely r. domesticus, r. nasutus, r. neglectus, r. neivai and r. ... | 2008 | 18304894 |
| genetic transformation of a corynebacterial symbiont from the chagas disease vector triatoma infestans. | insect-borne diseases have experienced a troubling resurgence in recent years. emergence of resistance to pesticides greatly hampers control efforts. paratransgenesis, or the genetic transformation of bacterial symbionts of disease vectors, is an alternative to traditional approaches. previously, we developed paratransgenic lines of rhodnius prolixus, a vector of chagas disease in central america. here, we report identification of a corynebacterial species as a symbiont of triatoma infestans, a ... | 2008 | 18331732 |
| molecular genetics reveal that silvatic rhodnius prolixus do colonise rural houses. | rhodnius prolixus is the main vector of chagas disease in venezuela. here, domestic infestations of poor quality rural housing have persisted despite four decades of vector control. this is in contrast to the southern cone region of south america, where the main vector, triatoma infestans, has been eliminated over large areas. the repeated colonisation of houses by silvatic populations of r. prolixus potentially explains the control difficulties. however, controversy surrounds the existence of s ... | 2008 | 18382605 |
| ecto-phosphatase activity on the external surface of rhodnius prolixus salivary glands: modulation by carbohydrates and trypanosoma rangeli. | the salivary glands of insect's vectors are target organs to study the vectors-pathogens interactions. rhodnius prolixus an important vector of trypanosoma cruzi can also transmit trypanosoma rangeli by bite. in the present study we have investigated ecto-phosphatase activity on the surface of r. prolixus salivary glands. ecto-phosphatases are able to hydrolyze phosphorylated substrates in the extracellular medium. we characterized these ecto-enzyme activities on the salivary glands external sur ... | 2008 | 18407240 |
| preliminary characterization of a rhodnius prolixus hemolymph trypanolytic protein, this being a determinant of trypanosoma rangeli kp1(+) and kp1(-) subpopulations' vectorial ability. | rhodnius prolixus is the main trypanosoma rangeli vector in several latin-american countries and is susceptible to infection with kp1(+) strains; however, it presents an invasion-resistant response to kp1(-) strains. the present work has identified a trypanolytic protein against t. rangeli kp1(-) in the r. prolixus hemolymph which was fractioned with ammonium sulfate (following dialysis). the results revealed a protein component which did not depend on divalent cations for its biological functio ... | 2008 | 18425269 |
| transmission dynamics of trypanosoma cruzi determined by low-stringency single primer polymerase chain reaction and southern blot analyses in four indigenous communities of the sierra nevada de santa marta, colombia. | this study attempted to evaluate the transmission dynamics of trypanosoma cruzi in four indigenous communities of sierra nevada de santa marta (snsm), colombia. low-stringency single primer-polymerase chain reaction (lssp-pcr) of the minicircles and southern blot analyses were used to characterize samples from patients, vectors, and reservoirs in these communities. the lssp-pcr profiles revealed a high genetic variability but with similarities among the parasites present in the samples of vector ... | 2009 | 19706903 |
| characteristics of plasminogen binding to trypanosoma cruzi epimastigotes. | the binding constants of the interaction between plasminogen and trypanosoma cruzi epimastigotes were determined. an indirect method in which the bound plasminogen is detached from the cell by epsilon-aminocaproic acid and a direct method through biotinylated plasminogen were used. the analyses revealed a dissociation constant (kd) from 0.4 to 1.2microm, these values being compatible with recognition in vivo. moreover, epimastigotes from the gut of rhodnius prolixus were able to bind plasminogen ... | 2008 | 18501871 |
| learning and orientation to odor in the bug rhodnius prolixus stal 1859 under laboratory conditions. | two experiments are described investigating learning and orientation in the triatomine rhodnius prolixus. in experiment 1, pavlovian conditioning was investigated. the experiment differed from our previous work in that the intensity of the conditioned and unconditioned stimuli were reduced and the number of training trials increased. once again, no evidence for pavlovian conditioning was found. in experiment 2, an "orientation arena" was developed in which the orientation of r. prolixus to a hum ... | 2008 | 18509679 |
| isolation, cloning, and expression mapping of a gene encoding an antidiuretic hormone and other capa-related peptides in the disease vector, rhodnius prolixus. | after a blood meal, rhodnius prolixus undergoes a rapid diuresis to eliminate excess water and salts. during the voiding of this primary urine, r. prolixus acts as a vector of chagas' disease, with the causative agent, trypanosoma cruzi, infecting the human host via the urine. diuresis in r. prolixus is under the neurohormonal control of serotonin and peptidergic diuretic hormones, and thus, diuretic hormones play an important role in the transmission of chagas' disease. although diuretic hormon ... | 2008 | 18511504 |
| experimental transmission of the parasitic flagellates trypanosoma cruzi and trypanosoma rangeli between triatomine bugs or mice and captive neotropical bats. | trypanosoma cruzi and trypanosoma rangeli-like trypanosomes have been found in a variety of neotropical bat species. in this study, bats (artibeus lituratus, carollia perspicillata, desmodus rotundus, glossophaga soricina, molossus molossus, phyllostomus hastatus) were maintained under controlled conditions, and experiments were conducted to determine how they might become infected naturally with trypanosomes. all bats were first screened for existing infections by hemoculture and the examinatio ... | 2007 | 17710299 |
| current situation of chagas disease in central america. | chagas disease in central america is known since 1913 when the first human case was reported in el salvador. the other central american countries reported their first cases between 1933 and 1967. on october 1997 was launched the central american initiative for chagas disease control (ipca). the objectives of this sub-regional initiative are: (1) the elimination of rhodnius prolixus in central america; (2) the reduction of the domiciliary infestation of triatoma dimidiata; and (3) the elimination ... | 2007 | 17713679 |
| oral transmission of trypanosoma cruzi with opposing evidence for the theory of carnivory. | we present the first demonstration of oral transmission of trypanosoma cruzi to raccoons (procyon lotor), a natural reservoir host in the united states, by ingestion of trypomastigotes and infected bugs, but not infected tissue. to investigate an alternative, non-vector-based transmission method, we tested the hypothesis that raccoons scavenging on infected hosts results in patent infection. macerated tissue from selected organs infected with amastigote stages of t. cruzi was orally administered ... | 2009 | 18763853 |
| trypanosoma cruzi infection is enhanced by vector saliva through immunosuppressant mechanisms mediated by lysophosphatidylcholine. | trypanosoma cruzi, the etiological agent of chagas disease, is transmitted by bug feces deposited on human skin during a blood meal. however, parasite infection occurs through the wound produced by insect mouthparts. saliva of the triatominae bug rhodnius prolixus is a source of lysophosphatidylcholine (lpc). here, we tested the role of both triatomine saliva and lpc on parasite transmission. we show that vector saliva is a powerful inducer of cell chemotaxis. a massive number of inflammatory ce ... | 2008 | 18794282 |
| hyaluronidase of bloodsucking insects and its enhancing effect on leishmania infection in mice. | salivary hyaluronidases have been described in a few bloodsucking arthropods. however, very little is known about the presence of this enzyme in various bloodsucking insects and no data are available on its effect on transmitted microorganisms. here, we studied hyaluronidase activity in thirteen bloodsucking insects belonging to four different orders. in addition, we assessed the effect of hyaluronidase coinoculation on the outcome of leishmania major infection in balb/c mice. | 2008 | 18820742 |
| trypanosoma cruzi congenital transmission in wild bats. | trypanosoma cruzi congenital transmission in wild bats (molossus molossus), associated with infected rhodnius prolixus in a natural habitat from a rural locality in western venezuela, is reported. t. cruzi blood circulating trypomastigotes in a pregnant bat were detected by parasitological methods. polymerase chain reaction (pcr) assays carried out in samples from the heart and the fetus of the same infected female, revealed the presence of t. cruzi-specific dna in both of the tissues, demonstra ... | 2009 | 18823929 |
| lipid mediators and vector infection: trypanosoma rangeli inhibits rhodnius prolixus hemocyte phagocytosis by modulation of phospholipase a2 and paf-acetylhydrolase activities. | in this work we investigated the effects of trypanosoma rangeli infection through a blood meal on the hemocyte phagocytosis in experiments using the 5th instar larvae of rhodnius prolixus. hemocyte phagocytic activity was strongly blocked by oral infection with the parasites. in contrast, hemocyte phagocytosis inhibition caused by t. rangeli infection was rescued by exogenous arachidonic acid (20 microg/insect) or platelet activating factor (paf; 1 microg/insect) applied by hemocelic injection. ... | 2008 | 18835273 |
| trypanosoma cruzi: biological characterization of lineages i and ii supports the predominance of lineage i in colombia. | the causes of the particular distribution of both trypanosoma cruzi lineages throughout the american continent remain unknown. in colombia, t. cruzi i is the predominant group in both domestic and sylvatic cycles. here, we present the biological characterization of t. cruzi parasites belonging to both t. cruzi i and t. cruzi iib groups. our results show the inability of the t. cruzi iib clones to infect mammalian cells, produce trypomastigotes and replicate in rhodnius prolixus, the main vector ... | 2009 | 18950627 |
| discovery of a novel insect neuropeptide signaling system closely related to the insect adipokinetic hormone and corazonin hormonal systems. | neuropeptides and their g protein-coupled receptors (gpcrs) play a central role in the physiology of insects. one large family of insect neuropeptides are the adipokinetic hormones (akhs), which mobilize lipids and carbohydrates from the insect fat body. other peptides are the corazonins that are structurally related to the akhs but represent a different neuropeptide signaling system. we have previously cloned an orphan gpcr from the malaria mosquito anopheles gambiae that was structurally inter ... | 2010 | 20068045 |