| [presence of neuraminidase in rhodnius prolixus infected with trypanosoma rangeli]. | using three different methods, the activity of neuraminidase was studied in the promesenteron, postmesenteron, rectal ampulla, haemolymph and salivary glands in 600 rhodnius prolixus experimentally infected with trypanosoma rangeli stock san agustín. the haemagglutination method with peanut lectin, and the fluorescence test with peanut lectin conjugated with fluorescein isothiocyanate, and the fluorescence emitted by 4-methylumbelliferone showed in all cases the presence of neuraminidase in the ... | 1992 | 1345317 |
| the distribution of agglutinins and lytic activity against trypanosoma rangeli and erythrocytes in rhodnius prolixus and triatoma infestans tissue extracts and haemolymph. | haemolymph, heads, salivary glands, crops, midguts, hindguts, and malpighian tubules from rhodnius prolixus and triatoma infestans were extracted in phosphate or tris buffer saline with calcium, and tested for agglutination and lytic activities by microtitration against both vertebrate erythrocytes and cultured epimastigote forms of trypanosoma rangeli. haemagglutination activity against rabbit erythrocytes was found in the crop, midgut and hindgut extracts of t. infestans but only in the haemol ... | 1991 | 1842412 |
| the prophenoloxidase system and in vitro interaction of trypanosoma rangeli with rhodnius prolixus and triatoma infestans haemolymph. | the presence of the prophenoloxidase (propo) system in the haemolymph of rhodnius prolixus and triatoma infestans and the role played by trypanosoma rangeli in the in vitro activation of propo were tested. both r. prolixus and t. infestans whole blood preparations showed a very active propo system. the propo cascade of the two insect species were differentially activated by microbial-derived extracts: laminarin was a better activator of t. infestans haemolymph than of r. prolixus blood, and lipo ... | 1991 | 1956701 |
| development and interactions of trypanosoma rangeli in and with the reduviid bug rhodnius prolixus. | two strains of trypanosoma rangeli and three strains of rhodnius prolixus were used in various combinations to transmit the trypanosomes via the reduviid bug. a persisting infection in the midgut lumen posterior to the stomach resulted in all 2,500 bugs being third and fourth instars. infectious, metacyclic forms developed exclusively in the salivary glands; forms excreted with bug feces were noninfectious to mice. the midgut epithelium was the main barrier to transmission of the parasite. in on ... | 1990 | 2186407 |
| use of total parasite dna probes for the direct detection of trypanosoma cruzi and trypanosoma rangeli in domicilliary rhodnius prolixus. | | 1990 | 2189249 |
| binding of lectins to culture and vector forms of trypanosoma rangeli tejera, 1920 (protozoa, kinetoplastida) and to structures of the vector gut. | culture forms of trypanosoma rangeli could be agglutinated with canavalia ensiformis (con a) lectin and, less effectively with pisum sativum agglutinin (pea), at a concentration of 200 micrograms/ml. ricinus communis agglutinin i (rca i) agglutinated trypanosomes only if they were not previously washed with physiological ringer's solution. three other lectins did not react with the same parasite forms. direct or indirect lectin-gold labeling techniques were applied to lr-white embedded thin sect ... | 1989 | 2689636 |
| the affinity of the lectins ricinus communis and glycine maxima to carbohydrates on the cell surface of various forms of trypanosoma cruzi and trypanosoma rangeli, and the application of these lectins for the identification of t. cruzi in the feces of rhodnius prolixus. | flagellates of trypanosoma cruzi (stock molino 1), obtained from the intestine of experimentally infected rhodnius prolixus, grown in cellular or acellular culture, as well as from the blood of infected mice, were examined by a direct fluorescence test using the lectins rca (ricinus communis-120) and sba (soy bean agglutinin; glycine maxima), conjugated with fluorescein isothiocyanate, for the detection of beta-d-galactose and alpha,beta-n-acetyl-d-galactosamine on the membranes of the flagellat ... | 1986 | 2877548 |
| trypanosoma (herpetosoma) leeuwenhoeki in choloepus hoffmanni and didelphis marsupialis of the pacific coast of colombia. | trypanosoma (herpetosoma) leeuwenhoeki, originally described in panamanian sloths, was isolated from didelphis marsupialis (marsupialia) and choloepus hoffmanni (edentata) inhabiting the pacific coast of colombia. trypanosomes were characterized by their large blood forms (total length 51-53 microns), poor infectivity for mice, and lack of development in rhodnius prolixus. isoenzyme studies, with either strains or clones, revealed homogeneous profiles clearly distinct from trypanosoma cruzi and ... | 1989 | 2926591 |
| trypanosoma cruzi and trypanosoma rangeli in saimiri sciureus from bolivia and saguinus mistax from brazil. | examination of blood films for trypanosomes in primates housed at the tulane university delta regional primate research center showed that 47% (32/68) of the bolivian saimiri sciureus and 51% (68/135) of brazilian saguinus mistax harbored one or more types: trypanosoma (schizotrypanum) cruzi in 6% to 7% and trypanosoma (herpetosoma) spp. or trypanosoma (megatrypanum) spp. in 39% and 45%, respectively. trypanosomes were isolated from a sample of the infected monkeys and morphobiological studies w ... | 1986 | 3082228 |
| [laboratory maintenance of trypanosoma (herpetosoma) rangeli tejera, 1920]. | two laboratory maintenance systems of trypanosoma rangeli were compared. the maintenance by weekly subinoculations in tobie's culture medium and the intrafemoral inoculation of rhodnius prolixus with cultured flagellates, resulted in loss of infectivity of the metacyclic salivarian trypomastigotes for mice, ten months after maintenance in culture. with the system of cyclical passes through culture-rhodnius-mouse-culture-rhodnius, the infectivity of the metacyclic trypomastigotes for mice, was ma ... | 1986 | 3313550 |
| studies on trypanosoma rangeli tejera, 1920. ix. course of infection in different stages of rhodnius prolixus. | frequent individual observations od different stages of rhodnius prolixus exposed to trypanosoma rangeli, revealed a higher susceptibility to infection in the bugs exposed during the two first instars. the mortality rate in infected bugs was significantly higher than in controls, indicating that the parasite was responsible for the majority of deaths. an analysis of the mortality distribution, per instar, is presented. statistical analysis of deaths among the different infected instars, showed t ... | 1987 | 3333807 |
| rhodnius neivai: a new experimental vector of trypanosoma rangeli. | rhodnius neivai was as efficient as rhodnius prolixus and rhodnius robustus in transmitting by bite a colombian strain of trypanosoma rangeli following its inoculation into the hemocoel. under conditions of the study the strain of t. rangeli had a high and constant infectivity to the salivary glands of r. prolixus, its natural vector in colombia. six species of triatoma and dipetalogaster maximus likewise inoculated did not develop metatrypomastigotes in the salivary glands. of the 12 known spec ... | 1986 | 3518505 |
| lack of enzyme polymorphism in trypanosoma rangeli stocks from sylvatic and domiciliary transmission cycles in colombia. | although trypanosoma rangeli is biologically and morphologically distinct from trypanosoma cruzi, these two hemoflagellates are epidemiologically linked. we report the results of enzyme electrophoretic studies of t. rangeli stocks isolated from sylvatic and domiciliary rhodnius prolixus, and infected humans inhabiting foci in which t. cruzi was sympatrically transmitted. t. rangeli stocks displayed electrophoretically detectable polymorphism for only a single enzyme, isocitrate dehydrogenase (ic ... | 1987 | 3812885 |
| natural infections and behavior of trypanosoma rangeli and trypanosoma cruzi in the vector rhodnius prolixus in colombia. | | 1969 | 4980776 |
| histology of rhodnius prolixus infected with trypanosoma rangeli. | | 1971 | 4997588 |
| observations on the development of trypanosoma rangeli in the hemocoel of rhodnius prolixus. | | 1970 | 5442845 |
| trypanosoma rangeli: effect on excretion in rhodnius prolixus. | | 1971 | 5558074 |
| pathogenicity of trypanosoma rangeli for rhodnius prolixus stal in nature (hemiptera: reduviidae) (kinetoplastida: trypanosomatidae). | | 1968 | 5699971 |
| biological factors influencing transmission of trypanosoma rangeli by rhodnius prolixus. | | 1965 | 5857287 |
| studies on trypanosoma rangeli tejera, 1920. vii--its effect on the survival of infected triatomine bugs. | the pathological effects of trypanosoma rangeli on rhodnius prolixus and r. robustus, and the relation of mortality to infection, were studied under laboratory conditions. frequent observations revealed that when the first instar nymphs of r. prolixus and r. robustus were infected with t. rangeli, survival of the bugs during the stages of development to the adult stage decreased. this decrease was statistically significant when compared with uninfected control-bugs, indicating that t. rangeli is ... | 1984 | 6399091 |
| studies on trypanosoma rangeli tejera, 1920. vi. developmental pattern in the haemolymph of rhodnius prolixus. | the morphological sequence of trypanosoma rangeli development in the body cavity of rhodnius prolixus is described. the metacyclic trypanosome is the product of successive division and transformation during the intra and extracellular development in the haemocoele. the significance of the early invasion of t. rangeli into the haemolymph is discussed. the epidemiological importance of the developmental pattern of t. rangeli in the vectors haemolymph and the host-response to the parasite are consi ... | 1983 | 6400168 |
| epidemiology of trypanosoma cruzi in the oriental plains of colombia. | epidemiologic studies to define the domiciliary and extradomiciliary transmission cycles of trypanosoma cruzi and trypanosoma rangeli in the oriental plains of colombia were conducted in the gallery forests near carimagua and el porvenir. one-hundred and seven palm trees belonging to nine genera were examined; triatomines were found in only three palm species, the leaves of which are locally used for roof thatching: 2/29 maximiliana elegans, 1/7 mauritia flexuosa and 7/7 scheelea sp. bugs were a ... | 1984 | 6439062 |
| the effect of lampit on trypanosoma rangeli in experimentally infected mice. | mice experimentally inoculated with metacyclic forms of trypanosoma rangeli were given orally 10, 25, 50 or 100 mg/kg of body weight/day of lampit on 20 consecutive days. the results of combined examinations of fresh blood, giemsa stained blood preparations, blood cultures, blood concentration, repeated xenodiagnosis with rhodnius prolixus and blind passages via triatomine bites to other mice demonstrated that a dose of 50 to 100 mg/kg/day of the drug eliminated t. rangeli from the blood of all ... | 1982 | 6814024 |
| the penetration of the salivary glands of rhodnius prolixus by trypanosoma rangeli. | ultrastructural studies of the mechanism of penetration of the salivary gland of the reduviid bug rhodnius prolixus by trypanosoma rangeli showed that trypanosomes from the haemocoele penetrate the outer "membranes" of the gland flagellum foremost, disrupting the inner layers, to pass between the muscle cells to reach the gland cell basement membrane. this latter is also penetrated flagellum foremost, the parasite invaginating the gland cell plasmalemma beneath, to create a vacuole in which the ... | 1980 | 6994382 |
| early invasion of trypanosoma rangeli into the haemolymph of rhodnius prolixus. | | 1980 | 7001694 |
| detection of trypanosoma rangeli by salivation of infected rhodnius prolixus on glass slides. | | 1980 | 7008724 |
| infectivity of trypanosoma rangeli in a promonocytic mammalian cell line. | the existence of an intracellular stage of trypanosoma rangeli in the vertebrate host was evaluated by experimental infection of the u937 histiocytic cell line with the san agustín strain and the ub66-5b clone. the identity of the parasites at the beginning and end of the experiments was confirmed through biological behavior in the vector and mammal hosts, isoenzymes, polymerase chain reaction (pcr), and monoclonal antibodies. infectivity to u937 cells of t. rangeli obtained from culture and sal ... | 1995 | 7472856 |
| trypanosoma cruzi and trypanosoma rangeli: interplay with hemolymph components of rhodnius prolixus. | studies were carried out on the course of infection of trypanosoma cruzi (clone dm28c) and trypanosoma rangeli (clone san agustin) and their interactions with hemolymph components of rhodnius prolixus. these parasites when inoculated into the hemocoel of adult r. prolixus (i) had different courses of infection (t. rangeli had high rates of both multiplication and infection and t. cruzi had no division and disappeared soon from the hemolymph); (ii) induced high but no differential increases in ly ... | 1995 | 7745280 |
| randomly amplified polymorphic dna (rapd) and isoenzyme analysis of trypanosoma rangeli strains. | sixteen trypanosoma rangeli strains were compared by isoenzyme and randomly amplified polymorphic dna (rapd) analysis. eight strains were isolated from either rhodnius prolixus or homo sapiens from honduras, colombia and venezuela. another eight strains were isolated from either panstrongylus megistus or the rodent echimys dasythrix from the state of santa catarina, southern brazil. all six t. rangeli strains isolated from p. megistus were co-infections with trypanosoma cruzi, demonstrating an o ... | 1994 | 8049688 |
| rhodnius prolixus: salivary antihemostatic components decrease with trypanosoma rangeli infection. | feeding behavior and some antihemostatic properties of the saliva of rhodnius prolixus infected with trypanosoma rangeli were studied and compared with those of uninfected controls. insects with salivary gland infection pierced host skin more often and drew less blood and at a lower rate than controls when feeding on a rabbit. none of these differences was observed when feeding was performed through a membrane feeder. salivary gland homogenates from infected insects, at 30 days after feeding/inf ... | 1994 | 8162960 |
| trypanosoma cruzi and erythrocyte agglutinins: a comparative study of occurrence and properties in the gut and hemolymph of rhodnius prolixus. | the activity of agglutinins found in the gut tissues and hemolymph of rhodnius prolixus was tested using rabbit erythrocytes, trypanosoma cruzi, or trypanosoma rangeli as test particles. in addition, investigations were made of the influence of parasitic infection and insect diet on the agglutination titers. a range of physicochemical tests and carbohydrate-binding studies were performed and inhibitors were subsequently found for both the crop agglutinin (p-nitrophenol-derived sugars) and the he ... | 1996 | 8654555 |
| studies on a haemolymph lectin isolated from rhodnius prolixus and its interaction with trypanosoma rangeli. | we demonstrated that in rhodnius prolixus haemocyte monolayers, both trypanosoma cruzi and trypanosoma rangeli are capable of inducing haemocyte/parasite clump formation. we also purified, by one-step affinity chromatography, a haemolymph galactoside-binding lectin from r. prolixus which we believe could play an important role in the development of t. rangeli in the haemocoel of the insect vector. this lectin markedly enhanced the activation of clump formation by t. rangeli in r. prolixus haemoc ... | 1999 | 10092472 |
| species specific detection of trypanosoma cruzi and trypanosoma rangeli in vector and mammalian hosts by polymerase chain reaction amplification of kinetoplast minicircle dna. | several groups have recently developed molecular tests for the detection of trypanosoma cruzi, the causative agent of chagas' disease. polymerase chain reaction (pcr) amplification of kinetoplast minicircle dna sequences appears to be the most sensitive method. however, the specificity of pcr-based diagnostic methods was challenged when the complete sequence of trypanosoma rangeli dna minicircles was discovered. in the present study, we conducted. pcr experiments using the s35/s36 primers in rho ... | 1999 | 10206119 |
| rhodnius prolixus infected with trypanosoma rangeli: in vivo and in vitro experiments. | studies were carried out on the activation of the prophenoloxidase (propo) in adults of rhodnius prolixus infected by short and long epimastigote forms of trypanosoma rangeli. the in vitro activation of the propo cascade using l-dopa as substrate was very low in the absence of fat body extract, hemolymph, and parasites. on the other hand, a higher po activity was observed when short, but not long, epimastigotes of t. rangeli were incubated with fresh hemolymph, fat body extract, and l-dopa. supe ... | 1999 | 10222183 |
| metalloproteases in trypanosoma rangeli-infected rhodnius prolixus. | protease activities in the haemolymph and fat body in a bloodsucking insect, rhodnius prolixus, infected with trypanosoma rangeli, were investigated. after sds-polyacrylamide gel electrophoresis containing gelatin as substrate, analysis of zymograms performed on samples of different tissues of controls and insects inoculated or orally infected with short or long epimastigotes of t. rangeli, demonstrated distinct patterns of protease activities: (i) proteases were detected in the haemolymph of in ... | 1999 | 10585653 |
| an electron microscopic study of penetration by trypanosoma rangeli into midgut cells of rhodnius prolixus. | the process of interaction of the choachi strain of trypanosoma rangeli with intestinal epithelial cells of rhodnius prolixus was analyzed in experiments carried out in vitro and in vivo. for the in vitro experiments small fragments of the anterior region of the posterior midgut were incubated in the presence of the parasites, fixed, and processed for observation with the scanning electron microscope. parasites attached to the surface of some epithelial cells, especially to the extracellular mem ... | 2001 | 11161989 |
| amplification of a specific repetitive dna sequence for trypanosoma rangeli identification and its potential application in epidemiological investigations. | trypanosoma rangeli can infect humans as well as the same domestic and wild animals and triatomine vectors infected by trypanosoma cruzi in central and south america. this overlapping distribution complicates the epidemiology of american trypanosomiasis due to the cross-reactivity between t. rangeli and t. cruzi antigens and the presence of conserved dna sequences in these parasites. we have isolated a t. rangeli-specific dna repetitive element which is represented in approximately 103 copies pe ... | 2000 | 11162365 |
| differential susceptibility of triatomines of the genus rhodnius to trypanosoma rangeli strains from different geographical origins. | the susceptibility of four rhodnius species to different trypanosoma rangeli strains was evaluated using both intracoelomic inoculation and oral infection. rhodnius prolixus, rhodnius domesticus, rhodnius neglectus and rhodnius nasutus were infected with trypanosoma rangeli macias (venezuela), choachi (colombia) and sc-58 (brazil) strains, revealing distinct haemolymph and salivary glands infection rates. the obtained infection rates were revealed to be dependent on the method of infection and t ... | 2001 | 11334954 |
| role of superoxide and reactive nitrogen intermediates in rhodnius prolixus (reduviidae)/trypanosoma rangeli interactions. | this study compares aspects of the superoxide, nitric oxide and prophenoloxidase pathways in rhodnius prolixus hemolymph, measured in parallel, in response to trypanosoma rangeli inoculation. responses to two strains of t. rangeli, and two developmental forms, were studied, and the results obtained were correlated with the ability of the parasites to survive, multiply, and complete their life cycles in the hemolymph of the host. t. rangeli h14 strain parasites, which fail to complete their life ... | 2001 | 11426951 |
| kdna markers define two major trypanosoma rangeli lineages in latin-america. | trypanosoma rangeli is a hemoflagellate parasite of man, domestic and wild animals in central and south america. the genus rhodnius is particularly susceptible to infection by t. rangeli and transmission by salivary inoculation has been demonstrated in 12 of 14 nominal species of naturally and experimentally infected insects. this report describes the molecular characterization of 37 strains of t. rangeli isolated from vertebrate and invertebrate hosts. strains were analyzed by hybridization wit ... | 2002 | 11755434 |
| development of symbionts in triatomine bugs and the effects of infections with trypanosomatids. | in the intestinal tract of fifth instars of the hematophagous reduviid bugs rhodnius prolixus and triatoma infestans blood ingestion induced an initial decrease of the concentration of the respective symbiotic bacteria rhodococcus rhodnii and nocardia sp. and then within 10 days a 15- or 18-fold increase of the total population/bug to about 0.8 x 10(9) colony-forming units in r. prolixus and 1.8 x 10(9) colony-forming units in t. infestans. about 95-99% of the total populations of both symbionts ... | 2002 | 11971650 |
| effects of gamma irradiation on the development of trypanosoma rangeli in the vector rhodnius prolixus. | studies on the effects of gamma radiation on the infectivity of trypanosoma rangeli (strain h14) for the vector rhodnius prolixus revealed that (i) the ld(50) (lethal dose for 50% of bugs) for uninfected insects was 4147 rads; (ii) irradiated insects with a dose of 1200 rads subsequently infected with the flagellates exhibited a mortality of 45%, while uninfected irradiated insects showed a mortality of 5%, and infected nonirradiated insects exhibited 10% mortality; (iii) flagellates were presen ... | 2002 | 12095237 |
| identification and distribution of carbohydrate moieties on the salivary glands of rhodnius prolixus and their possible involvement in attachment/invasion by trypanosoma rangeli. | in the present study, fitc-labelled lectins (wga, con a, pna, hpa, and tpa) were utilized to investigate carbohydrate residues on the surface of rhodnius prolixus salivary glands. the results revealed that the salivary glands are rich in carbohydrate moieties and the diversity in binding pattern of particular lectins showed the presence of specific carbohydrate residues in the basal lamina, muscle, and cell layers of the glands. subsequently, the sugars detected on the salivary gland surface wer ... | 2002 | 12128049 |
| epidemiology of chagas disease in guatemala: infection rate of triatoma dimidiata, triatoma nitida and rhodnius prolixus (hemiptera, reduviidae) with trypanosoma cruzi and trypanosoma rangeli (kinetoplastida, trypanosomatidae). | a five-year domiciliary collection in the 22 departments of guatemala showed that out of 4,128 triatomines collected, 1,675 were triatoma dimidiata (latreille, 1811), 2,344 were rhodnius prolixus stal 1859, and only 109 were t. nitida usinger 1939. the chagas disease parasite, trypanosoma cruzi, was found in all three species. their natural infection rates were similar in the first two species (20.6%; 19.1%) and slightly lower in t. nitida(13.8%). however there was no significant difference in t ... | 2003 | 12886407 |
| [data on trypanosoma rangeli tejera, 1920, i. technic for obtaining it from the salivary gland of rhodnius prolixus]. | | 1958 | 13586728 |
| increased infectivity of a cyclically maintained strain of trypanosoma rangeli to rhodnius prolixus and mode of transmission by invertebrate host. | | 1964 | 14215475 |
| further morphological studies on the behavior of trypanosoma rangeli in the hemocytes of rhodnius prolixus. | the hemocytes of rhodnius prolixus were analyzed during the course of infection with the protozoan trypanosoma rangeli. the following cell types were identified: prohemocyte, plasmatocyte, adipocyte, granular cell and oenocytoid. the number of these cells changes during the infection course thus indicating a cell response to infection of r. prolixus by t. rangeli. transmission electron microscopy showed that plasmatocytes were able to ingest epimastigote forms of the parasite, which were then fo ... | 2003 | 14665386 |
| effects of eicosanoid biosynthesis inhibitors on the prophenoloxidase-activating system and microaggregation reactions in the hemolymph of rhodnius prolixus infected with trypanosoma rangeli. | investigations on the effects of eicosanoid biosynthesis inhibitors on the hemocyte microaggregation and prophenoloxidase (propo)-activating system in the hemolymph, parasitemia and mortality of rhodnius prolixus infected with trypanosoma rangeli were performed. hemocoelic injection of live t. rangeli epimastigotes into fifth-instar larvae of r. prolixus that previously fed on blood containing an inhibitor of phospholipase a(2) (dexamethasone), a specific inhibitor of the cyclooxygenase pathway ... | 2004 | 15019517 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 rangeli: a new perspective for studying the modulation of immune reactions of rhodnius prolixus. | abstract: insects are exposed to a wide range of microorganisms (bacteria, fungi, parasites and viruses) and have interconnected powerful immune reactions. although insects lack an acquired immune system they have well-developed innate immune defences that allow a general and rapid response to infectious agents.over the last few decades we have observed a dramatic increase in the knowledge of insect innate immunity, which relies on both humoral and cellular responses. however, innate reactions t ... | 2009 | 19615044 |
| trypanosoma rangeli genotypes association with rhodnius prolixus and r. pallescens allopatric distribution in central america. | previous kdna polymorphism-based reports have revealed the existence of two trypanosoma rangeli genotypes (kp1+ and kp1-): sl and ssu rrna gene polymorphism-based studies have revealed that five genotypes (a-e) are distributed throughout different latin-american countries. some evidence has shown that the genotypes' biogeographical distribution is associated with sympatric rhodnius species. 12 t. rangeli isolates from humans and reservoirs from el salvador, guatemala, honduras, costa rica and pa ... | 2009 | 19778637 |
| trypanosoma rangeli: differential expression of ecto-phosphatase activities in response to inorganic phosphate starvation. | in this work, we showed that living cells of trypanosoma rangeli express different ecto-phosphatase activities in response to different inorganic phosphate (pi) concentrations in the culture medium. the ecto-phosphatase activity from t. rangeli grown at low-pi concentration was inhibited by the increase of the ph, while the ecto-phosphatase of the cells grown at high pi concentration was not modulated by the change of the ph of the medium. okadaic acid inhibited only the ecto-phosphatase activit ... | 2010 | 20034491 |
| a standardizable protocol for infection of rhodnius prolixus with trypanosoma rangeli, which mimics natural infections and reveals physiological effects of infection upon the insect. | trypanosoma rangeli is a protozoan parasite that shares hosts - mammals and triatomines - with trypanosoma cruzi, the etiological agent of chagas disease. although t. rangeli is customarily considered to be non-pathogenic to human hosts, it is able to produce pathologies in its invertebrate hosts. however, advances are hindered by a lack of standardization of infection procedures and these pathologies need documentation. to establish a suitable, and standardizable, infection protocol, the durati ... | 2010 | 20546751 |
| effects of infection by trypanosoma cruzi and trypanosoma rangeli on the reproductive performance of the vector rhodnius prolixus. | the insect rhodnius prolixus is responsible for the transmission of trypanosoma cruzi, which is the etiological agent of chagas disease in areas of central and south america. besides this, it can be infected by other trypanosomes such as trypanosoma rangeli. the effects of these parasites on vectors are poorly understood and are often controversial so here we focussed on possible negative effects of these parasites on the reproductive performance of r. prolixus, specifically comparing infected a ... | 2014 | 25136800 |
| trypanosomes modify the behavior of their insect hosts: effects on locomotion and on the expression of a related gene. | as a result of evolution, the biology of triatomines must have been significantly adapted to accommodate trypanosome infection in a complex network of vector-vertebrate-parasite interactions. arthropod-borne parasites have probably developed mechanisms, largely still unknown, to exploit the vector-vertebrate host interactions to ensure their transmission to suitable hosts. triatomines exhibit a strong negative phototaxis and nocturnal activity, believed to be important for insect survival agains ... | 2015 | 26291723 |
| rhodnius prolixus interaction with trypanosoma rangeli: modulation of the immune system and microbiota population. | trypanosoma rangeli is a protozoan that infects a variety of mammalian hosts, including humans. its main insect vector is rhodnius prolixus and is found in several latin american countries. the r. prolixus vector competence depends on the t. rangeli strain and the molecular interactions, as well as the insect's immune responses in the gut and haemocoel. this work focuses on the modulation of the humoral immune responses of the midgut of r. prolixus infected with t. rangeli macias strain, conside ... | 2015 | 25888720 |
| rhodnius prolixus: from physiology by wigglesworth to recent studies of immune system modulation by trypanosoma cruzi and trypanosoma rangeli. | this review is dedicated to the memory of professor sir vincent b. wigglesworth (vw) in recognition of his many pioneering contributions to insect physiology which, even today, form the basis of modern-day research in this field. insects not only make vital contributions to our everyday lives by their roles in pollination, balancing eco-systems and provision of honey and silk products, but they are also outstanding models for studying the pathogenicity of microorganisms and the functioning of in ... | 2017 | 27866813 |
| behavioral fever response in rhodnius prolixus (reduviidae: triatominae) to intracoelomic inoculation of trypanosoma cruzi. | behavioral fever is a response to infections with microorganisms observed in some poikilothermic animals. rhodnius prolixus is involved in the transmission of two parasites: trypanosoma cruzi (pathogenic for humans and transmitted in feces) and trypanosoma rangeli (non-pathogenic for humans, pathogenic for rhodnius and transmitted by the bite of an infected individual). only t. rangeli is found in the hemolymph of rhodnius as it travels to the salivary glands. | 2017 | 27598628 |
| glycogen synthase kinase-3 is involved in glycogen metabolism control and embryogenesis of rhodnius prolixus. | rhodnius prolixus is a blood-feeding insect that transmits trypanosoma cruzi and trypanosoma rangeli to vertebrate hosts. rhodnius prolixus is also a classical model in insect physiology, and the recent availability of r. prolixus genome has opened new avenues on triatomine research. glycogen synthase kinase 3 (gsk-3) is classically described as a key enzyme involved in glycogen metabolism, also acting as a downstream component of the wnt pathway during embryogenesis. gsk-3 has been shown to be ... | 2016 | 27574112 |
| triatomine physiology in the context of trypanosome infection. | triatomines are hematophagous insects that feed on the blood of vertebrates from different taxa, but can occasionally also take fluids from invertebrate hosts, including other insects. during the blood ingestion process, these insects can acquire diverse parasites that can later be transmitted to susceptible vertebrates if they complete their development inside bugs. trypanosoma cruzi, the etiological agent of chagas disease, and trypanosoma rangeli are protozoan parasites transmitted by triatom ... | 2017 | 27401496 |
| what is the 'true' effect of trypanosoma rangeli on its triatomine bug vector? | the phrase, "t. rangeli is pathogenic to its insect vector," is commonly found in peer-reviewed publications on the matter, such that it has become the orthodox view of this interaction. in a literature survey, we identified over 20 papers with almost the exact phrase and several others alluding to it. the idea is of particular importance in triatomine population dynamics and the study of vector-borne t. cruzi transmission, as it could mean that triatomines infected with t. rangeli have lower fi ... | 2016 | 27232121 |
| trypanosoma cruzi-trypanosoma rangeli co-infection ameliorates negative effects of single trypanosome infections in experimentally infected rhodnius prolixus. | trypanosoma cruzi, causative agent of chagas disease, co-infects its triatomine vector with its sister species trypanosoma rangeli, which shares 60% of its antigens with t. cruzi. additionally, t. rangeli has been observed to be pathogenic in some of its vector species. although t. cruzi-t. rangeli co-infections are common, their effect on the vector has rarely been investigated. therefore, we measured the fitness (survival and reproduction) of triatomine species rhodnius prolixus infected with ... | 2016 | 27174360 |
| comparative proteomic analysis of the saliva of the rhodnius prolixus, triatoma lecticularia and panstrongylus herreri triatomines reveals a high interespecific functional biodiversity. | triatomines are hematophagous arthropods that transmit trypanosoma cruzi and trypanosoma rangeli. feeding behavior and pathogen transmission is known to vary between the different species, and this characteristic is directly or indirectly dependent on the bioactive molecules of the saliva that facilitate the vector-host-parasite interaction. here, we identify, characterize and compare the sialoproteomic (from the greek sialo: saliva) repertoire of important species of the main triatomine genera ... | 2016 | 26940473 |
| genotyping of trypanosoma cruzi dtus and trypanosoma rangeli genetic groups in experimentally infected rhodnius prolixus by pcr-rflp. | the specific detection and genetic typing of trypanosomes that infect humans, mammalian reservoirs, and vectors is crucial for diagnosis and epidemiology. we utilized a pcr-rflp assay that targeted subunit ii of cytochrome oxidase and 24sα-rdna to simultaneously detect and discriminate six trypanosoma cruzi discrete typing units (dtus) and two genetic groups of trypanosoma rangeli (kp1+/kp1-) in intestinal contents of experimentally infected rhodnius prolixus. the pcr assays showed that in 23 of ... | 2016 | 26792202 |
| validation of reference genes for expression analysis in the salivary gland and the intestine of rhodnius prolixus (hemiptera, reduviidae) under different experimental conditions by quantitative real-time pcr. | rhodnius prolixus is a blood-feeding insect that can transmit trypanosoma cruzi and trypanosoma rangeli to vertebrate hosts. recently, genomic resources for invertebrate vectors of human pathogens have increased significantly, and r. prolixus has been one of the main species studied among the triatomines. however, the paucity of information on many of the fundamental molecular aspects of this species limits the use of the available genomic information. the present study aimed to facilitate gene ... | 2012 | 22395020 |
| temperature and parasite life-history are important modulators of the outcome of trypanosoma rangeli-rhodnius prolixus interactions. | trypanosoma rangeli is a protozoan parasite, which does not cause disease in humans, although it can produce different levels of pathogenicity to triatomines, their invertebrate hosts. we tested whether infection imposed a temperature-dependent cost on triatomine fitness using t. rangeli with different life histories. parasites cultured only in liver infusion tryptose medium (cultured) and parasites exposed to cyclical passages through mice and triatomines (passaged) were used. we held infected ... | 2016 | 27460893 |
| rhodnius prolixus: modulation of antioxidant defenses by trypanosoma rangeli. | trypanosoma rangeli is a protozoan parasite of insects and mammals that is challenged by the constant action of reactive oxygen species, generated either by its own metabolism or through the host immune response. the aim of this work was to investigate whether t. rangeli is able to modify the redox state of its insect vector, rhodnius prolixus, through the modulation of such antioxidant enzymes as superoxide dismutase (sod), catalase, and gpx present in the midgut of the insect. we verified that ... | 2014 | 25131776 |
| the interaction between trypanosoma rangeli and the nitrophorins in the salivary glands of the triatomine rhodnius prolixus (hemiptera; reduviidae). | the parasite trypanosoma rangeli develops in the intestinal tract of triatomines and, particularly in species of the genus rhodnius, invades the hemolymph and salivary glands, where subsequent metacyclogenesis takes place. many aspects of the interaction between t. rangeli and triatomines are still unclear, especially concerning the development of the parasite in the salivary glands and how the parasite interacts with the saliva. in this work, we describe new findings on the process of t. rangel ... | 2013 | 23295786 |
| interaction between trypanosoma rangeli and the rhodnius prolixus salivary gland depends on the phosphotyrosine ecto-phosphatase activity of the parasite. | trypanosoma rangeli is the trypanosomatid that colonizes the salivary gland of its insect vector, with a profound impact on the feeding capacity of the insect. in this study we investigated the role of the phosphotyrosine (p-tyr) ecto-phosphatase activity of t. rangeli in its interaction with rhodnius prolixus salivary glands. long but not short epimastigotes adhered to the gland cells and the strength of interaction correlated with the enzyme activity levels in different strains. differential i ... | 2012 | 22749957 |