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characterization of the external female genitalia of six species of triatominae (hemiptera: reduviidade) by scanning electron microscopy.by macroscopic and microscopic dorsal side observation, it was noted that the ix and x segments of two species each of panstrongylus and triatoma terminate in an elongated way, whereas they terminate abruptly in the two species of rhodnius. scanning observation of the dorsal, ventral, lateral and posterior sides of the female genitalia of panstrongylus herreri, panstrongylus megistus, rhodnius colombiensis, rhodnius prolixus, triatoma infestans and triatoma vitticeps revealed that these six spec ...201020512241
the first pacifastin elastase inhibitor characterized from a blood sucking animal.pacifastin-like protease inhibitors belong to a recent classified protease inhibitor family and they are the smallest protease inhibitors described in animals. in this work, we purified and characterized, for the first time, two neutrophil elastase inhibitors belonging to the pacifastin family from the blood sucking insect triatoma infestans eggs. the inhibitors showed the same n-terminal sequences, molecular masses of 4257 and 4024da by maldi-tof mass spectrometry and dissociation constants (ki ...201020381560
ultrastructural analysis of the nucleolar aspects at spermiogenesis in triatomines (heteroptera, triatominae).in this study the ultrastructural technique was used to analyze seminiferous tubule cells of the triatomine species panstrongylus megistus, rhodnius pallescens and triatoma infestans. the data obtained provided evidence of the phenomenon known as persistence of the nucleolar material in initial spermatids at early differentiation. our results confirmed the presence of the nucleolus and its products during spermiogenesis up to the formation of the axoneme and during spermatid elongation in all th ...201020619665
cardioacceleratory and myostimulatory activity of allatotropin in triatoma infestans.haematophagous insects incorporate a large quantity of blood with each meal, producing a big quantity of urine in a few hours. the activity of the malpighian tubules (mts) is facilitated by the increase of the circulation of the haemolymph produced by the increase of the aorta contractions as well as, of the peristaltic waves of the anterior midgut. mts of triatoma infestans secrete an allatotropin-like peptide, which has a myostimulatory effect on the hindgut, inducing the mixing and voiding of ...201019995615
distribution and characterization of corazonin in the central nervous system of triatoma infestans (insecta: heteroptera).the distribution of corazonin in the central nervous system of the heteropteran insect triatoma infestans was studied by immunohistochemistry. the presence of corazonin isoforms was investigated using maldi-tof mass spectrometry in samples containing the brain, the subesophageal ganglion, the corpora cardiaca-corpus allatum complex and the anterior part of the aorta. several groups of immunopositive perikarya were detected in the brain, the subesophageal ganglion and the thoracic ganglia. regard ...201121029760
[chagas disease control program in the state of são paulo, brazil: seroepidemiological aspects of homogeneous geographic microregions].between the years 1976 and 1980, the american trypanosomiasis was searched for among residents in two geographic microregions of the state of são paulo: campos de itapetininga, in the region of sorocaba, and encosta ocidental da mantiqueira paulista, in the region of campinas. both areas have in the past been colonized by triatoma infestans. campos de itapetininga remained, until the beginning of the 1970s as a stronghold of this species in the state of são paulo. panstrongylus megistus has curr ...201121584362
composition and anti-insect activity of essential oils from tagetes l. species (asteraceae, helenieae) on ceratitis capitata wiedemann and triatoma infestans klug.essential oils from four species of the genus tagetes l. (asteraceae, helenieae) collected in tucumán province, argentina, were evaluated for their chemical composition, toxicity, and olfactory activity on mediterranean fruit fly ceratitis capitata wiedemann adults and for repellent properties on triatoma infestans (klug) (chagas disease vector). yields of essential oils range from 0.2 to 0.8% (v/w). the same main constituents among tagetes minuta l., tagestes rupestris cabrera, and tagetes ter ...201121469658
activity of metarhizium spp. and isaria spp. from the central brazilian cerrado against triatoma infestans nymphs.entomopathogenic fungi attack chagas disease vectors, and there is a need of effective isolates for development of biological control. ten isolates of metarhizium spp., four of isaria cateniannulata and two of an isaria sp., all isolated with triatoma infestans as a bait insect from soils collected in central brazil, and tested under laboratory conditions were effective against third instar nymphs of t. infestans. this is the first report of pathogenicity of m. flavoviride var. pemphigi, m. robe ...201121621234
[control program of chagas disease in são paulo, brazil: the control and surveillance of vector transmission].the control of the vectors of chagas' disease in the state of sao paulo are discussed, mainly those activities that led to the elimination of triatoma infestans. secondary factors that helped the control such as rural exodus are also analyzed. the article shows that since 1965 the control became a campaign with different phases due to the epidemiological situation, the acquired knowledge and the entomological surveillance. after 25 years of work, the elimination of all the focus of triatoma infe ...201121584361
spatial distribution of at- and gc-rich dna within interphase cell nuclei of triatoma infestans klug.heterochromatin bodies in single- and multichromocentered interphase cell nuclei of triatoma infestans, a vector of chagas disease, have been suggested to contain at-rich dna, based on their positive response to q-banding and hoechst 33248 treatment. no information exists on whether gc-rich dna is also present in these nuclei and whether it plays a role on chromatin condensation. considering that methodologies more precise than those previously used to determine dna base composition in situ are ...201121382722
transport and utilization of free fatty acids in triatoma infestans.triatoma infestans hemolymph has 0.31 mg/ml of free fatty acids and 2.8 mg/ml of diacylglycerols. almost all the diacylglycerols are transported by lipophorin whereas free fatty acids are carried by lipophorin and a very high density lipoprotein. the binding of cis-parinaric acid to lipophorin was employed to specify the free fatty acid binding properties of lipophorin. lipophorin has 10 binding sites of high affinity (3 x 10(7)) and approximately 45 binding sites of low affinity (1 x 10(6)). th ...20113060117
hidden sylvatic foci of the main vector of chagas disease triatoma infestans: threats to the vector elimination campaign?establishing the sources of reinfestation after residual insecticide spraying is crucial for vector elimination programs. triatoma infestans, traditionally considered to be limited to domestic or peridomestic (abbreviated as d/pd) habitats throughout most of its range, is the target of an elimination program that has achieved limited success in the gran chaco region in south america.201122039559
secondary kill effect of deltamethrin on triatoma infestans.control of the chagas disease vector, triatoma infestans, relies on the application of pyrethroid insecticides, especially deltamethrin. we performed laboratory studies to determine whether a t. infestans nymph that comes into contact with a deltamethrin-treated surface horizontally transfers the insecticide to subsequent triatomines. we found that a triatomine that walks on a deltamethrin-treated surface for a short period of time has the ability to transport the insecticide in concentrations s ...201121845956
[entomological survey (1975-1983)].after the systematization and re-dimension of the vectorial control in all the country by 1975, it was considered necessary to have an up-to-date information on the distribution of vectors in brazil, and differentiate precisely the role of each of the different species on the intra-domiciliary transmission of chagas disease. for this purpose, sampling regional surveys for regions with non reliable information were performed, as well as, a house by house search for vectors on those areas consider ...201121584354
susceptibility of sylvatic triatoma infestans from andeans valleys of bolivia to deltamethrin and fipronil.we describe the susceptibility to deltamethrin and fipronil of four sylvatic triatoma infestans populations from the andean valleys of bolivia. fifty percent lethal doses were determined from topical application of insecticide on first instars, and mortality was assessed after 24 h for deltamethrin and 48 h for fipronil. in comparison with a reference strain from argentina, the bolivian populations showed deltamethrin 50 percent lethal dose ratios ranging from 1.9 to 17.4. in the case of fiproni ...201121845942
genetic variability, phylogenetic relationships and gene flow in triatoma infestans dark morphs from the argentinean chaco.the recent discovery of sylvatic populations of triatoma infestans outside the andean valleys of bolivia prompted an evolutionary question about the putative ancestral area of origin and dispersal of the species, and an epidemiological question regarding the possible role of these sylvatic populations in the recolonization process of insecticide-treated houses. the finding of a population of sylvatic melanic t. infestans (dark morphs) in the argentinean dry chaco at 7 km from a peridomestic bug ...201121352954
differential control of light-dark adaptation in the ocelli and compound eyes of triatoma infestans.the adaptation to light of compound eyes in insects has been extensively documented and their adaptive role is well understood. much less attention has been paid, however, to the control of ocelli sensitivity, a study which could help us to understand the functional role of these simple eyes. we analyzed the dynamic changes in the distribution of screening pigments which occur in the ocelli of the haematophagous bug, triatoma infestans, when the insects are subjected either to light/dark cycles ...201121856308
head morphometry and isoenzymatic profile of two triatoma infestans klůg, 1834 (hemiptera, reduviidae) populations.the triatomine bug triatoma infestans was probably originated in bolivia and dispersed passively over large areas of south america, where it is the major vector of trypanosoma cruzi. in its probable origin area this species shows two different patterns of behaviour, being found both in sylvatic and human related habitats. such behaviour is not observed in other areas of its distribution, where it is exclusive to human related habitats. the main objective of the present study was to evaluate head ...201119653989
molecular phylogeography of the chagas' disease vector triatoma infestans in argentina.triatoma infestans is the main vector of chagas' disease in south america between latitudes 10°s and 46°s. a multilocus microsatellite data set of 836 individuals from 27 populations of t. infestans, from all its range of distribution in argentina, was analyzed. our results favor the hypothesis of two independent migration events of colonization in argentina and secondary contacts. the majority of the populations of the western provinces of catamarca, la rioja, san juan and the west of cordoba p ...201121224874
new insights on the chagas disease main vector triatoma infestans (reduviidae, triatominae) brought by the genetic analysis of bolivian sylvatic populations.triatoma infestans is the main and most widespread vector of chagas disease in south america. for the first time, a large sample of sylvatic populations of t. infestans was analyzed by its-2 and mtcytb sequencing. its-2 showed a low level of polymorphism but revealed a dichotomy between the andean and non-andean sylvatic populations. on the contrary, mtcytb sequences showed a high polymorphism (19 haplotypes determined by 35 variable sites) revealing a strong structuring between most of the sylv ...201121463708
[chagas disease control program in the state of são paulo, brazil: serological and entomological aspects of primary school-children surveys].two serological surveys were carried out to evaluate the effectiveness of measures put into effect in the state of são paulo (brazil) to control chagas disease vectors. the first one, during the period from 1968 to 1970; the complement fixation reaction was performed on serum samples from school-children resident in all municipalities of the state of são paulo, with the exception of the greater são paulo. the second one, annually, from 1973 to 1983, involving school-children resident in municipa ...201121584363
detection of trypanosoma cruzi in untreated chronic chagasic patients is improved by using three parasitological methods simultaneously.objectives this study compared three parasitological methods applied simultaneously in individuals with untreated chronic chagas' disease in order to determine their individual and combined performances. methods from a total of 100 chronic chagasic patients from endemic areas of chile, with informed consent, we extracted 2 ml of peripheral venous blood for pcr (pcr-b) and applied two xenodiagnosis (xd) boxes with seven uninfected triatoma infestans nymphs each for microscopic examination and pcr ...201121798882
Trypanosoma cruzi Genotypes of Insect Vectors and Patients with Chagas of Chile Studied by Means of Cytochrome b Gene Sequencing, Minicircle Hybridization, and Nuclear Gene Polymorphisms.Abstract Fifty-six Trypanosoma cruzi stocks from Chile and neighboring countries and different hosts, humans, and Triatoma infestans and Mepraia sp., vectors of domiciliary and natural environments were characterized by using three molecular markers. These were cytochrome b (Cyt b) gene sequencing, minicircle DNA blotting, and hybridization with five genotype-specific DNA probes and nuclear analysis of 1f8 and gp72 by polymerase chain reaction-restriction fragment length polymorphism. The resu ...201122022808
influence of the quality and quantity of blood ingested on reproductive parameters and life-span in triatoma infestans (klug).in triatominae, female fecundity and fertility may be affected by age, adult nutritional status (i.e., blood meal source and amount of blood ingested) and number of matings. triatoma infestans (klug) is the main vector of chagas disease in southern south america and considering that reproductive success is intimately associated with the potential for colonizing or re-colonizing new ecotopes in endemic areas, we studied whether the blood meal source and the amount of blood ingested have influence ...201121672510
trypanosoma cruzi discrete typing units (dtus): microsatellite loci and population genetics of dtus tcv and tci in bolivia and peru.trypanosoma cruzi, the agent of chagas disease, is usually subdivided into six discrete typing units (dtus), tci to tcvi, among which tci and tcv are most common in human infections in bolivia. multilocus microsatellite typing (mlmt) was selected to further explore the structure of the natural populations belonging to these dtus. the analysis showed that microsatellite clustering does not fully match the six dtus, but it is relevant for the within dtus analyses. population genetics analysis was ...201121801854
variability of the susceptibility to deltamethrin in triatoma infestans: the female factor.we analyzed the variability of susceptibility to deltamethrin in putatively susceptible triatoma infestans klug (hemiptera: reduviidae), and evaluated the sample size implications on the hypotheses used in the current world health organization protocol for the measure of insecticide resistance in triatominae. following the protocol, using topical application of deltamethrin to unfed first instar nymphs of t. infestans, we found that susceptibility showed significant differences between offspring ...201122238875
Factors affecting infestation by Triatoma infestans in a rural area of the humid Chaco in Argentina: a multi-model inference approach.Transmission of Trypanosoma cruzi by Triatoma infestans remains a major public health problem in the Gran Chaco ecoregion, where understanding of the determinants of house infestation is limited. We conducted a cross-sectional study to model factors affecting bug presence and abundance at sites within house compounds in a well-defined rural area in the humid Argentine Chaco.201122028941
infestin 1r, an intestinal subtilisin inhibitor from triatoma infestans able to impair mammalian cell invasion by trypanosoma cruzi.infestins are kazal-type serine protease inhibitors described in the midgut of triatoma infestans, chagas disease vector. of all infestins, only infestin 1r (inf1r) does not control host blood coagulation, due to its inhibitory specificity for chymotrypsin-like proteases. we further investigated the effect of inf1r on cell infection by trypanosoma cruzi. the importance of inf1r reactive site to inhibit t. cruzi cell invasion was confirmed using 1rsfti, a synthetic cyclic peptide containing the i ...201121963772
retracing micro-epidemics of chagas disease using epicenter regression.vector-borne transmission of chagas disease has become an urban problem in the city of arequipa, peru, yet the debilitating symptoms that can occur in the chronic stage of the disease are rarely seen in hospitals in the city. the lack of obvious clinical disease in arequipa has led to speculation that the local strain of the etiologic agent, trypanosoma cruzi, has low chronic pathogenicity. the long asymptomatic period of chagas disease leads us to an alternative hypothesis for the absence of cl ...201121935346
contribution of at-, gc-, and methylated cytidine-rich dna to chromatin composition in malpighian tubule cell nuclei of panstrongylus megistus (hemiptera, reduviidae).the malpighian tubule cell nuclei of male panstrongylus megistus, a vector of chagas disease, contain one chromocenter, which is composed solely of the y chromosome. considering that different chromosomes contribute to the composition of chromocenters in different triatomini species, the aim of this study was to determine the contribution of at-, gc-, and methylated cytidine-rich dna in the chromocenter as well as in euchromatin of malpighian tubule cell nuclei of p. megistus in comparison with ...201122197484
Diatomaceous earth and oil enhance effectiveness of Metarhizium anisopliae against Triatoma infestans.Entomopathogenic fungi, especially Metarhizium anisopliae, have potential for integrated control of peridomestic triatomine bugs. However, the high susceptibility of these vectors to fungal infection at elevated ambient humidities decreases in the comparatively dry conditions that often prevail in their microhabitats. A formulation adapted to this target pest that induces high and quick mortality can help to overcome these drawbacks. In the present study diatomaceous earth, which is used against ...201122155570
Intestinal aspartate proteases TiCatD and TiCatD2 of the haematophagous bug Triatoma infestans (Reduviidae): Sequence characterisation, expression pattern and characterisation of proteolytic activity.Two aspartate protease encoding complementary deoxyribonucleic acids (cDNA) were characterised from the small intestine (posterior midgut) of Triatoma infestans and the corresponding genes were named TiCatD and TiCatD2. The deduced 390 and 393 amino acid sequences of both enzymes contain two regions characteristic for cathepsin D proteases and the conserved catalytic aspartate residues forming the catalytic dyad, but only TiCatD2 possesses an entire C-terminal proline loop. The amino acid sequen ...201122210150
The infra-red (IR) landscape of Triatoma infestans. An hypothesis about the role of IR radiation as a cue for Triatominae dispersal.This paper presents the infrared (IR) emission spectrum of hosts and habitats of Triatoma infestans in the chaco region of NW Argentina, representing the first attempt to correlate the natural infrared stimulus with the known behaviour of these blood-sucking insect, vectors of Trypanosoma cruzi - causative agent of Chagas disease. The study was carried out in two rural villages of La Rioja Province (Argentina). A FLYR i40 camera was used to obtain IR pictures which were analyzed to determine the ...201121856443
Tigutcystatin, a cysteine protease inhibitor from Triatoma infestans midgut expressed in response to Trypanosoma cruzi.The insect Triatoma infestans is a vector of Trypanosoma cruzi, the etiological agent of Chagas disease. A cDNA library was constructed from T. infestans anterior midgut, and 244 clones were sequenced. Among the EST sequences, an open reading frame (ORF) with homology to a cystatin type 2 precursor was identified. Then, a 288-bp cDNA fragment encoding mature cystatin (lacking signal peptide) named Tigutcystatin was cloned fused to a N-terminal His tag in pET-14b vector, and the protein expressed ...201121875578
geographical structuring of trypanosoma cruzi populations from chilean triatoma infestans triatomines and their genetic relationship with other latino american counterparts.in order to obtain more information about the population structure of chilean trypanosoma cruzi, and their genetic relationship with other latino american counterparts, we performed the study of t. cruzi samples detected in the midgut content of triatoma infestans insects from three endemic regions of chile. the genetic characteristics of these samples were analysed using microsatellite markers and pcr conditions that allow the detection of predominant t. cruzi clones directly in triatomine midg ...201122325822
Cuticular hydrocarbon pattern as a chemotaxonomy marker to assess intraspecific variability in Triatoma infestans, a major vector of Chagas' disease.Triatoma infestans Klug (Hemiptera: Reduviidae) populations were sampled in various localities throughout most of the species' geographic range of distribution in Argentina, Bolivia, Paraguay and Peru. In order to contribute to understanding of the diversity and population structure of this major vector of Chagas' disease, cuticular hydrocarbon (CHC) profiles were analysed by capillary gas chromatography and variations evaluated by statistical methods of classification and ordination. High level ...201121929581
plant extracts, isolated phytochemicals, and plant-derived agents which are lethal to arthropod vectors of human tropical diseases--a review.the recent scientific literature on plant-derived agents with potential or effective use in the control of the arthropod vectors of human tropical diseases is reviewed. arthropod-borne tropical diseases include: amebiasis, chagas disease (american trypanosomiasis), cholera, cryptosporidiosis, dengue (hemorrhagic fever), epidemic typhus (brill-zinsser disease), filariasis (elephantiasis), giardia (giardiasis), human african trypanosomiasis (sleeping sickness), isosporiasis, leishmaniasis, lyme di ...201121432748
epicuticle lipids mediate mate recognition in triatoma infestans.epicuticular lipids are contact cues in intraspecific chemical communication in insects, both for aggregation and sexual behavior. triatomine bugs are vectors of the parasite trypanosoma cruzi, the cause of chagas disease. in triatoma infestans, the major epicuticular lipids are hydrocarbons, fatty alcohols, and free and esterified fatty acids. previously, we found that epicuticular lipid extracts, or selected fatty acid components, trigger aggregation and arrestment behavior in this bug. using ...201121373991
gene discovery in triatoma infestans.triatoma infestans is the most relevant vector of chagas disease in the southern cone of south america. since its genome has not yet been studied, sequencing of expressed sequence tags (ests) is one of the most powerful tools for efficiently identifying large numbers of expressed genes in this insect vector.201121418565
anti-triatomine saliva immunoassays for the evaluation of impregnated netting trials against chagas disease transmission.insecticide-impregnated nets can kill triatomine bugs, but it remains unclear whether they can protect against chagas disease transmission. in a field trial in quequeña, peru, sentinel guinea pigs placed in intervention enclosures covered by deltamethrin-treated nets showed significantly lower antibody responses to saliva of triatoma infestans compared with animals placed in pre-existing control enclosures. our results strongly suggest that insecticide-treated nets prevent triatomine bites and c ...201121426907
influence of the intestinal anticoagulant in the feeding performance of triatomine bugs (hemiptera; reduviidae).triatomines are haematophagous insects in all post-embryonic life stages. they are vectors of trypanosoma cruzi, the causative agent of chagas disease. their vectorial ability is influenced by their feeding performance, which varies greatly amongst species. recent work showed that inhibition of the coagulation process in the anterior midgut (crop) environment considerably influences the blood meal size. in this work, we performed a comparative study of the level of anticoagulant activity in the ...201121447340
"andean" and "non-andean" its-2 and mtcytb haplotypes of triatoma infestans are observed in the gran chaco (bolivia): population genetics and the origin of reinfestation.in bolivia, the gran chaco ecoregion suffers from serious problems of house reinfestation with triatoma infestans despite vector control by insecticides spraying. in order to identify the origin of the triatomines collected after spraying, the genetic structure of t. infestans populations collected in four neighboring villages, before and after spraying, was analyzed using its-2 and mtcytb sequencing. before spraying, only the mtcytb marker detected genetic differentiation among the 4 population ...201121457795
importance and physiological effects of hemolymphagy in triatomines (hemiptera: reduviidae).triatomines are hematophagous insects and the vectors for trypanosoma cruzi in the americas. although their preferred meal is blood from vertebrate hosts, unfed triatomine nymphs are often seen feeding on different arthropod species. triatomine saliva has a wide range of activities that aid the hematophagic process. however, nothing is known about its role during hemolymphagy. in the current study, we reproduced hemolymphagy under laboratory conditions and evaluated the influence of hemolymphagy ...201121485376
structure elucidation and synthesis of dioxolanes emitted by two triatoma species (hemiptera: reduviidae).volatiles from the metasternal glands of two species of true bugs of the triatominae subfamily, triatoma brasiliensis and triatoma infestans, were analyzed by spme-gc/ms. two sets of new natural products were found: (4s,5s)- and (4r,5r)-2,2,4-triethyl-5-methyl-1,3-dioxolane (1) (major component) and (4s*,5s*)-2,4-diethyl-2,5-dimethyl-1,3-dioxolane (2) (trace component), (2r/s,4s,5s)- as well as (2r/s,4r,5r)-4-ethyl-5-methyl-2-(1-methylethyl)-1,3-dioxolane (3) (minor component), (2r/s,4s*,5s*)-4- ...201121486009
dispersal of triatoma infestans and other triatominae species in the arid chaco of argentina: flying, walking or passive carriage? the importance of walking females.the aim of this paper was to analyse the active dispersal of triatoma infestans and the role of chickens as passive carriers of this insect in peridomestic areas of la rioja, argentina. to measure active dispersal, monthly catches were made on six consecutive nights for five months (in the warm season) using light traps (for flying insects) and sticky dispersal barriers (for walking insects). the nutritional and reproductive states of adults were evaluated. over the course of the sampling period ...201121537686
essential oils of medicinal plants from the central andes of argentina: chemical composition, and antifungal, antibacterial, and insect-repellent activities.the antifungal, antibacterial, and insect-repellent activities of the essential oils (eos) of acantholippia seriphioides, artemisia mendozana, gymnophyton polycephalum, satureja parvifolia, tagetes mendocina, and lippia integrifolia, collected in the central andes area, province of san juan, argentina, were investigated. the dermatophytes microsporum gypseum, trichophyton mentagrophytes, and t. rubrum were inhibited by the eos of g. polycephalum, l. integrifolia, and s. parvifolia, with minimum ...201121560241
first report of colonies of sylvatic triatoma infestans (hemiptera: reduviidae) in the paraguayan chaco, using a trained dog.in the gran chaco region, control of triatoma infestans has been limited by persistent domestic infestations despite the efforts of the vector control services. in paraguay, this region is the highest endemic area in the country, showing high levels of indoor and outdoor infestation. although sylvatic t. infestans have been found in the bolivian and argentine chaco, similar searches for sylvatic populations of this species in paraguay had been unsuccessful over the last 20 years. here we present ...201121572522
[summary of results from the national surveys].this article aims to correlate the main results of three large national surveys on chagas disease (entomologic, seroprevalence and electrocardiographic) carried out in brazil from late 1970's to early 1980's, which served as baseline for definition of the control measures adopted in the country. the proportion of infected people was much higher in areas where triatoma infestans, the most efficient vector of chagas disease among the five principal species involved in transmission at that time, wa ...201121584357
[the control of vectorial transmission].between 1950 and 1951, the first prophylactic campaign against chagas diseases was carried on in brazil by the so existing serviço nacional de malária. the actions involving chemical vector control comprehended 74 municipalities along the rio grande valley, between the states of são paulo and minas gerais. ever since, until 1975, the activities were performed according the availability of resources, being executed with more or less regularity and coverage. at that time, chagas disease did no rep ...201121584358
[new challenges and the future of control].the epidemiological situation of chagas disease in brazil was substantially altered in the last decades, partially as a consequence of the control measures implemented and partially due to the environmental, economical and social changes that took place in the country. domicile vector transmission was interrupted when caused by triatoma infestans and importantly controlled when associated with native species of the vector. transfusion transmission is no longer a problem since generalized screeni ...201121584365
cholinesterase activity during embryonic development in the blood-feeding bug triatoma patagonica.triatoma patagonica del ponte (hemiptera: reduviidae), a vector of chagas' disease, is widely distributed in argentina and is found in sylvatic and peridomiciliary ecotopes, as well as occasionally in human dwellings after the chemical control of triatoma infestans. anti-cholinesteratic products can be applied in peridomiciliary areas and thus knowledge of cholinesterase activity during embryonic development in this species might contribute further information relevant to effective chemical cont ...201121671969
western blotting method (tesacruzi) as a supplemental test for confirming the presence of anti-trypanosoma cruzi antibodies in finger prick blood samples from children aged 0-5 years in brazil.some latin american countries have plans for total control and/or eradication of chagas disease by the main vector (triatoma infestans) and by blood transfusion. to achieve this, patients with chagas disease must be identified. a western blotting test, tesacruzi, is described as a supplemental test for diagnosis of chagas disease using samples collected from children <5 years living in different states of brazil. blood samples collected by finger prick on filter paper were sent to the test labor ...201120858452
[biochemistry of the development cycle of triatoma infestans (vinchuca). x. hemolymph lipoproteins of females].a lipoprotein of high density (hdl) and three of very high density (vhdl-i, vhdl-f and vhdl-ii) were separated by ultracentrifugation from t. infestans female hemolymph. lipids were mainly transported by hdl, whereas vhdl-ii presented the highest protein content. in all the lipoproteins, 1,2 and 1,3-diacylglycerols, triacylglycerols, free fatty acids, cholesterol, cholesterol esters and hydrocarbons, were present. phosphatidylcholine and phosphatidylethanolamine were also identified. the main li ...20123554896
morphology and molecular taxonomy of evlachovaea-like fungi, and the status of this unusual conidial genus.the entomopathogenic anamorphic genus evlachovaea was described to differ from other fungi in forming its conidia obliquely to the axis of the conidiogenous cell and with successive conidia having alternate orientations with a zipper- or chevron-like arrangement resulting in flat, ribbon-like chains. morphological and molecular studies of six evlachovaea-like isolates baited from central brazilian soils using triatoma infestans (a vector of chagas disease) and of other entomopathogens with evlac ...201223332828
the residual efficacy of a cypermethrin pour-on formulation applied on goats on the mortality and blood intake of triatoma infestans.triatoma infestans is the main vector of trypanosoma cruzi, the aetiological agent of chagas disease in the gran chaco region of south america. as a frequent blood meal source for triatomine bugs, domestic goats play a key role in the eco-epidemiology of chagas disease. the aim of this study was to evaluate the mortality and blood intake of t. infestans fed on goats that had been treated with different doses of pour-on insecticide. third-instar nymphs were fed on goats that had been treated with ...201223295751
selective factor xiia inhibition attenuates silent brain ischemia: application of molecular imaging targeting coagulation pathway.the purpose of this study was use molecular imaging targeting coagulation pathway and inflammation to better understand the pathophysiology of silent brain ischemia (sbi) and monitor the effects of factor xiia inhibition.201223153913
temporal differences in blood meal detection from the midguts of triatoma infestans.we used genus/species specific pcrs to determine the temporal persistence of host dna in triatoma infestans experimentally fed on blood from six common vertebrate species: humans, domestic dogs, guinea pigs, chickens, mice, and pigs. twenty third or fourth instar nymphs per animal group were allowed to feed to engorgement, followed by fasting-maintenance in the insectary. at 7, 14, 21, or 28 days post-feeding, the midgut contents from five triatomines per group were tested with the respective pc ...201222499421
identification of (l)-3-hydroxykynurenine o-sulfate in the buccal gland secretion of the parasitic lamprey, lethenteron japonicum.parasitic lampreys are known to secrete proteins having anticoagulant and vasodilator activities from the buccal glands during feeding on their host's blood. however, small molecules in the secretion have never been explored in detail. we examined the secretion of japanese liver lamprey (lethenteron japonicum) for small molecules and found an intensely fluorescent substance upon gel filtration. after purification by anion-exchange chromatography and reversed-phase hplc, structure of the compound ...201222648634
excito-repellency effect of deltamethrin on triatomines under laboratory conditions.this work demonstrates that deltamethrin in low doses produces an excito-repellency effect on triatomines, as already observed for mosquitoes. a wooden box covered with a cloth impregnated with deltamethrin at doses of 2.5 and 5mg ai/m2 was utilized for the experiment. the triatomine species studied were triatoma infestans, panstrongylus megistus, rhodnius neglectus and triatoma sordida. adults were released in one of the sides of the box and their position was noted in subsequent periods. the o ...201210967592
the development and validation of a risk score for household infestation by triatoma infestans, a bolivian vector of chagas disease.chagas disease, primarily spread in bolivia by the vector triatoma infestans, persists as an important public health problem. preventative insecticide campaigns target spraying on the basis of anecdotal evidence and there is a need for an accurate classification score to correctly identify 'at risk' houses. data were collected from 337 households on 11 variables through the use of a standardised questionnaire and survey. risk factors for infestation were identified and a risk score was developed ...201222975298
spatial heterogeneity and risk maps of community infestation by triatoma infestans in rural northwestern argentina.fifty years of residual insecticide spraying to control triatoma infestans in the gran chaco region of northern argentina, paraguay and bolivia shows that vertically coordinated interventions aiming at full coverage have limited effects and are unsustainable. we quantified the spatial distribution of t. infestans domestic infestation at the district level, identified environmental factors associated with high infestation and then explored the usefulness of risk maps for the spatial stratificatio ...201222905276
toxicity of non-pyrethroid insecticides against triatoma infestans (hemiptera: reduviidae).triatoma infestans (klug) is the main vector of chagas disease, which is a public health concern in most latin american countries. the prevention of chagas disease is based on the chemical control of the vector using pyrethroid insecticides. in the last decade, different levels of deltamethrin resistance have been detected in certain areas of argentina and bolivia. because of this, alternative non-pyrethroid insecticides from different chemical groups were evaluated against two t. infestans popu ...201222850959
lack of segregation between two species of chagas disease vectors.triatoma infestans and panstrongylus megistus are relevant chagas disease vectors. an apparent segregation among these triatomine species inside human households was suggested to rely on mutual repellence between them. however, p. megistus and t. infestans show aggregation responses to chemical signals emitted by the other species. these findings do not rule out the possibility that stimuli other than chemical signals could mediate repellence when these species exploit shelters simultaneously. i ...201222764300
geographic distribution of chagas disease vectors in brazil based on ecological niche modeling.although brazil was declared free from chagas disease transmission by the domestic vector triatoma infestans, human acute cases are still being registered based on transmission by native triatomine species. for a better understanding of transmission risk, the geographic distribution of brazilian triatomines was analyzed. sixteen out of 62 brazilian species that both occur in >20 municipalities and present synanthropic tendencies were modeled based on their ecological niches. panstrongylus genicu ...201222523500
identification of a point mutation associated with pyrethroid resistance in the para-type sodium channel of triatoma infestans, a vector of chagas' disease.the voltage-gated sodium channel is the target site of pyrethroid insecticides. point mutations in the domain ii region of the channel have been implicated in pyrethroid resistance of several insect species. we identified the sequence of domain ii from the para sodium channel in rhodnius prolixus, a vector of chagas' disease. with this information, we cloned and sequenced the domain ii of the sodium channel from the other main chagas' disease vector: triatoma infestans. we also identified the pr ...201222210132
post-control surveillance of triatoma infestans and triatoma sordida with chemically-baited sticky traps.chagas disease prevention critically depends on keeping houses free of triatomine vectors. insecticide spraying is very effective, but re-infestation of treated dwellings is commonplace. early detection-elimination of re-infestation foci is key to long-term control; however, all available vector-detection methods have low sensitivity. chemically-baited traps are widely used in vector and pest control-surveillance systems; here, we test this approach for triatoma spp. detection under field condit ...201223029583
susceptibility and resistance to deltamethrin of wild and domestic populations of triatoma infestans (reduviidae: triatominae) in bolivia: new discoveries.bolivia is a high-endemic country for chagas disease, for which the principal vector is triatoma infestans (triatominae). this is a mainly domestic species that is also found in the wild environment. recently, an increasing number of studies have shown the importance of triatominae resistance to insecticides, especially in bolivia. data regarding the susceptibility/resistance of wild and domestic populations of t. infestans to deltamethrin are presented. for the first time, domestic populations ...201223295756
mortality due to chagas disease in brazil from 1979 to 2009: trends and regional differences.studies on mortality due to parasitic diseases such as chagas disease are useful to understand the epidemiology and to plan and guide control measures for these diseases. we analyzed mortality trends due to chagas disease in brazil and regions, between 1979 and 2009.201223277508
scientific evidence of three different insecticide-resistant profiles in triatoma infestans (hemiptera: reduviidae) populations from argentina and bolivia.triatoma infestans (klug, 1834) (hemiptera, reduviidae) is the main vector of chagas disease in the southern cone south america. chemical control to the vectors appears to be the best option to reduce the incidence of the disease. however, since 2002, high resistance to insecticides that correlated with field control failures was detected in t. infestans from argentina and bolivia. in this paper, we analyzed three t. infestans populations whose pyrethroid-resistance had been recently detected, a ...201223270163
essential oil of azorella cryptantha collected in two different locations from san juan province, argentina: chemical variability and anti-insect and antimicrobial activities.the essential oils (eos) of two populations of azorella cryptantha (clos) reiche, a native species from san juan province, were obtained by hydrodistillation in a clevenger-type apparatus and characterized by gc-fid and gc/ms analyses. the compounds identified amounted to 92.3 and 88.7% of the total oil composition for a. cryptantha from bauchaceta (ac-bau) and agua negra (ac-an), respectively. the eo composition for the two populations was similar, although with differences in the identity and ...201222899606
new triatoma virus hosts in wild habitats of argentina.triatoma virus (trv), a member of the dicistroviridae family, replicates in intestinal epithelial cells, causing delayed development and death of infected individuals. the aims of this study were to find naturally infected species of triatominae in the wild in the region endemic for chagas disease and analyze and compare the sequence diversity of trv obtained from different triatominae. a total of 253 triatominae belonging to 10 species were captured by active or passive collection. three new se ...201222484232
differential pattern of infection of sylvatic nymphs and domiciliary adults of triatoma infestans with trypanosoma cruzi genotypes in chile.in chile, the main vector of chagas disease, triatoma infestans, is under control after insecticide spraying. however, it has been found colonizing wild habitats. this study evaluated trypanosoma cruzi infection of sylvatic and domiciliary t. infestans and identified their parasite genotypes. the sample studied was composed mainly of t. infestans sylvatic nymphs and domiciliary adults from a semi-urban area with human dwellings under vector control surveillance. results showed prevalences of 57. ...201222802439
genetic characterization of trypanosoma cruzi dtus in wild triatoma infestans from bolivia: predominance of tci.the current persistence of triatoma infestans (one of the main vectors of chagas disease) in some domestic areas could be related to re-colonization by wild populations which are increasingly reported. however, the infection rate and the genetic characterization of the trypanosoma cruzi strains infecting these populations are very limited.201222685616
the kazal-type inhibitors infestins 1 and 4 differ in specificity but are similar in three-dimensional structure.blood coagulation is an important process in haemostasis, and disorders of blood coagulation can lead to an increased risk of haemorrhage and thrombosis. coagulation is highly conserved in mammals and has been comprehensively studied in humans in the investigation of bleeding or thrombotic diseases. some substances can act as inhibitors of blood coagulation and may affect one or multiple enzymes throughout the process. a specific thrombin inhibitor called infestin has been isolated from the midg ...201222683792
chromatoid body: remnants of nucleolar proteins during spermatogenesis in triatomine (heteroptera, triatominae).in this study, we analyzed fibrillarin nucleolar protein expression in cbs of spermatogenic cells from testicular follicles of triatoma sordida and triatoma infestans. in the structural and ultrastructural analysis, it was used impregnation by silver ions, immunocytochemistry, immunofluorescence and transmission electron microscopy using antibodies against fibrillarin. regarding the results, the fibrillarin nucleolar protein marked the nucleus and some cytoplasmic spots of germ cells during sper ...201222575217
mg2+-dependent atpase activity in malpighian tubules of triatoma infestans klug.mg(2+)-dependent atpases were investigated in malpighian tubules of the blood-sucking insect, triatoma infestans, with cytochemical procedures for light and electron microscopy. the aim was to establish patterns of enzyme occurrence in the blood-sucking insect under control rearing conditions for further comparisons with animals subjected to the action of stress factors. enzyme activity was found in laminated "concretions" present in distal cells, in edges of urate crystals at the lumen of the p ...201222024318
microgeographic spatial structuring of triatoma infestans (hemiptera: reduviidae) populations using wing geometric morphometry in the argentine chaco.we investigated the occurrence of spatial structuring in triatoma infestans (klug) (hemiptera: reduviidae) populations 12 yr after the last community-wide insecticide spraying campaign in rural pampa del indio, in the gran chaco of northeastern argentina. in total, 172 male and 149 female right wings collected at 16 georeferenced sites with at least 10 individuals of the same sex were analyzed using geometric morphometry. mean female body length and wing centroid size (cs) were significantly lar ...201222679857
unexpected failures to control chagas disease vectors with pyrethroid spraying in northern argentina.effectiveness of the elimination efforts against triatoma infestans (klug) in south america through residual application of pyrethroid insecticides has been highly variable in the gran chaco region. we investigated apparent vector control failures after a standard community-wide spraying with deltamethrin sc in a rural area of northeastern argentina encompassing 353 houses. insecticide spraying reduced house infestation less than expected: from 49.5% at baseline to 12.3 and 6.7% at 4 and 8 mo po ...201223270166
scarce events of mitochondrial introgression in trypanosoma cruzi: new case with a bolivian strain.trypanosoma cruzi, the agent of chagas disease, presents a predominantly clonal structure that has been shaped by recombination events leading to six genetic groups (dtus, discrete typing units, tci-tcvi). several conventional and unconventional genetic exchange events have been described, including hybridization and mitochondrial introgression, which is explored here among bolivian and peruvian strains belonging to tci because recombination events have been previously suspected by means of the ...201222982157
effects of fipronil on dogs over triatoma infestans, the main vector of trypanosoma cruzi, causative agent of chagas disease.chagas disease is the most important endemic disease in latin america, mainly transmitted by triatoma infestans in the southern cone countries of south america. dogs are one of the main domestic reservoirs of trypanosoma cruzi, the etiological agent of chagas disease. the presence of dogs in rural households of endemic areas significantly increases the likelihood of the vectorial transmission of the parasite. we studied the mortality and blood intake of t. infestans exposed to dogs treated with ...201222669692
phylogenetic analysis of bolivian bat trypanosomes of the subgenus schizotrypanum based on cytochrome b sequence and minicircle analyses.the aim of this study was to establish the phylogenetic relationships of trypanosomes present in blood samples of bolivian carollia bats. eighteen cloned stocks were isolated from 115 bats belonging to carollia perspicillata (phyllostomidae) from three amazonian areas of the chapare province of bolivia and studied by xenodiagnosis using the vectors rhodnius robustus and triatoma infestans (trypanosoma cruzi marenkellei) or haemoculture (trypanosoma dionisii). the pcr dna amplified was analyzed b ...201222590570
new discoveries of sylvatic triatoma infestans (hemiptera: reduviidae) throughout the bolivian chaco.sylvatic populations of triatoma infestans might be involved in the recolonization of human dwellings. we report here the discoveries of new t. infestans sylvatic foci in the bolivian chaco. eighty-one triatomines were caught, 38 of which were identified as t. infestans. triatoma sordida and panstrongylus geniculatus were the other species collected. one t. infestans and one t. sordida were infected with trypanosoma cruzi tci; one t. infestans was infected with tcii. these discoveries add to the ...201222403316
synanthropic triatomines (hemiptera, reduviidae) in the state of pernambuco, brazil: geographical distribution and natural trypanosoma infection rates between 2006 and 2007.the present study shows a descriptive analysis of triatomine occurrence and its natural trypanosoma infection rates in the state of pernambuco, brazil, between 2006 and 2007.201222370830
real-time pcr in faecal samples of triatoma infestans obtained by xenodiagnosis: proposal for an exogenous internal control.the polymerase chain reaction (pcr) has proved to be a sensitive technique to detect trypanosoma cruzi in the chronic phase of chagas disease, which is characterized by low and fluctuating parasitemia. another technique proposed for parasitological diagnosis in this phase of infection combines a microscopic search for motile trypomastigote forms in faecal samples (fs) obtained by xenodiagnosis (xd) with conventional pcr (xd-pcr). in this study we evaluate the use of human blood dna as an exogeno ...201222448961
direct molecular identification of trypanosoma cruzi discrete typing units in domestic and peridomestic triatoma infestans and triatoma sordida from the argentine chaco.we assessed the distribution of trypanosoma cruzi discrete typing units (dtus) in domestic and peridomestic triatoma infestans and triatoma sordida specimens collected in a well-defined rural area in pampa del indio, northeastern argentina. microscopically-positive bugs were randomly selected with a multi-level sampling design, and dtus were identified using direct pcr strategies. tcvi predominated in 61% of 69 t. infestans and in 56% of 9 t. sordida. tcv was the secondary dtu in t. infestans (1 ...201223036510
elimination of rhodnius prolixus in central america.rhodnius prolixus is one of the main vectors of trypanosoma cruzi, causative agent of chagas disease. in central america, it was first discovered in 1915 in el salvador, from where it spread northwest to guatemala and mexico, and southeast to nicaragua and costa rica, arriving also in honduras in the late 1950s. indoor residual spraying (irs) by the antimalaria services of costa rica prevented its spread southwards, and similar irs programmes appear to have eliminated it from el salvador by the ...201222357219
[biological susceptibility of triatoma sordida and triatoma infestans to deltamethrin and lambdacyhalothrin under field conditions].the biological susceptibility of triatoma sordida and triatoma infestans to deltamethrin and lambdacyhalothrin was evaluated in three homogeneous groups of houses in the municipality of posse, goiás. each group of houses was treated according to one of the following protocols: deltamethrin 5% wetted powder at 25 mg a.i./m2; deltamethrin 5% concentrated suspension at 25 mg a.i./m2; and lambdacyhalothrin 10% wetted powder at 30 mg a.i./m2. monitoring of susceptibility to the insecticides was done ...20121842841
the central projection of cephalic mechanosensory axons in the haematophagous bug triatoma infestans.the projections of mechanosensory hairs located on the dorsal and lateral head of the adult haematophagous bug triatoma infestans were analyzed by means of cobalt filling. axons run into the anterior and posterior tegumentary nerve and project through the brain to the ventral nerve cord. the fibres are small in diameter and run as a fascicle. some branches run into suboesophageal and prothoracic centres; others run as far as to the mesothoracic ganglion. these sensory projections resemble that o ...201310800197
[laboratory study on measuring the insecticidal activity, on triatoma infestans, of lindane stored for 20 years]. 20132435299
adipokinetic hormone causes formation of low density lipophorin in the hemolymph of triatoma infestans. 20137885251
[sensitivity of the bug triatoma infestans klug. to dieldrin in relation to its stage of development and physiological condition]. 20134615261
differential expression profiles in the midgut of triatoma infestans infected with trypanosoma cruzi.chagas disease, or american trypanosomiasis, is a parasitic disease caused by the protozoan trypanosoma cruzi and is transmitted by insects from the triatominae subfamily. to identify components involved in the protozoan-vector relationship, we constructed and analyzed cdna libraries from rna isolated from the midguts of uninfected and t. cruzi-infected triatoma infestans, which are major vectors of chagas disease. we generated approximately 440 high-quality expressed sequence tags (ests) from e ...201323658688
population structure of the chagas disease vector, triatoma infestans, at the urban-rural interface.the increasing rate of biological invasions resulting from human transport or human-mediated changes to the environment has had devastating ecological and public health consequences. the kissing bug, triatoma infestans, has dispersed through the peruvian city of arequipa. the biological invasion of this insect has resulted in a public health crisis, putting thousands of residents of this city at risk of infection by trypanosoma cruzi and subsequent development of chagas disease. here, we show th ...201324103030
risk of transmission of trypanosoma cruzi by wild triatoma infestans (hemiptera: reduviidae) in bolivia supported by the detection of human blood meals.we analyzed the food sources of bolivian wild triatoma infestans (the main vector of chagas disease in this country), to assess the role of these populations in the epidemiological context of chagas disease. ninety-eight blood meals were identified by heteroduplex assay and sequencing. most of them were from wild mammals but surprisingly 27 were from humans. this brings to light the occurrence of human-vector contacts at risk of trypanosoma cruzi transmission in the wild environment by highly in ...201323856437
novel adipokinetic hormones in the kissing bugs rhodnius prolixus, triatoma infestans, dipetalogaster maxima and panstrongylus megistus.peptides of the adipokinetic hormone (akh)/red pigment-concentrating hormone (rpch) family were isolated and sequenced from the retrocerebral corpora cardiaca of four kissing bugs which are all vectors of the protozoan trypanosoma cruzi responsible for chagas' disease. the sequence of three novel akhs were deduced from the multiple ms(n) electrospray mass data: the octapeptide pglu-leu-thr-phe-ser-thr-asp-trp amide (denoted rhopr-akh) in rhodnius prolixus and panstrongylus megistus, the nonapept ...201323137850
predominance of hybrid discrete typing units of trypanosoma cruzi in domestic triatoma infestans from the bolivian gran chaco region.in the gran chaco region the reinfestation by triatoma infestans remains a major problem for control of chagas disease. trypanosoma cruzi the agent of the illness presents a broad genetic intraspecific variability which is poorly documented in the bolivian gran chaco. this work presents the identification of the discrete typing units (dtus) currently recognized for t. cruzi in t. infestans populations collected before and after residual insecticide spraying in four villages in this region. befor ...201323047136
trypanosoma cruzi genotypes in mepraia gajardoi from wild ecotopes in northern chile.we evaluated trypanosoma cruzi infection in 397 wild mepraia gajardoi specimens from five coastal localities in northern chile by detection of minicircle dna by polymerase chain reaction. the wild capture sites were classified into two ecotopes: a fully wild ecotope (ecotope 1) and a wild ecotope near human dwellings (ecotope 2). infection rates varied between 11% and 27%. minicircle hybridization assays showed that t. cruzi lineages tc ii and tc vi were commonly detected in ecotope 1 and ecotop ...201323249691
a country bug in the city: urban infestation by the chagas disease vector triatoma infestans in arequipa, peru.interruption of vector-borne transmission of trypanosoma cruzi remains an unrealized objective in many latin american countries. the task of vector control is complicated by the emergence of vector insects in urban areas.201324171704
microsatellite loci-based distribution of trypanosoma cruzi genotypes from chilean chronic chagas disease patients and triatoma infestans is concordant with a specific host-parasite association hypothesis.the objective of this study was to investigate if there is specific host-parasite association in chilean populations of trypanosoma cruzi. for this purpose, two groups of parasites were analyzed, one from chronic chagasic patients, and the other from triatoma infestans triatomines in three regions of the country. the first group consisted of four types of samples: parasites from peripheral blood of non-cardiopathic t. cruzi infected patients (nb); parasites from their corresponding xenodiagnosis ...201323666648
american trypanosomiasis.american trypanosomiasis is a parasitic disease caused by the flagellate protozoan trypanosoma cruzi. chagas disease is endemic in latin america, where an estimated 10-14 million people are infected, and an emerging disease in europe and the usa. trypanosoma cruzi is transmitted by blood-sucking bugs of the family reduviidae. rhodnius prolixus, panstrongylus megistus, triatoma infestans, and t. dimidiata are the main vectors in the sylvatic cycle. non vector-borne transmission includes blood tra ...201323829903
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