Showing papers by "Oswaldo Cruz Foundation published in 1988"
TL;DR: The results indicate that metacyclic trypomastigotes from the Dm 28c clone obtained under chemically defined conditions reproduce the biological behaviour of T. cruzi, rendering this system very suitable for the study of cell-parasite interactions and for the isolation of trypanosome relevant macromolecules.
Abstract: The biological characterization of the Trypanosoma cruzi clone Dm 28c in terms of its growth in LIT medium, cell-cycle, infectivity to mice and interaction with professional and non-professional phagocytic cells shows that it behaves as a bona fide T. cruzi representant. The biological properties of this myotropic clone do not change according to the origin of the trypomastigote forms (i. e., from triatomines, infected mice, cell-culture or from the chemically defined TAUP and TAU3AAG media). In addition Dm 28c metacyclic trypomastigotes from TAU3AAG medium display a high infectivity level to fibroblasts and muscle cells. Experiments on binding of cationized ferritin to trypomastigotes surface show the existence of cap-like structures of ferritin in regions near the kinetoplast. However the nature and role of these anionic sites remain to be determined. The results indicate that metacyclic trypomastigotes from Dm 28c clone obtained under chemically defined conditions reproduce the biological behaviour of T. cruzi, rendering this system very suitable for the study of cell-parasite interactions and for the isolation of trypanosome relevant macromolecules.
197 citations
TL;DR: The results suggest that epimastigote must adhere to a substrate before their transformation to metacyclic trypomastigotes, being released to the medium as the meetacyclogenesis process is accomplished, which could correspond to the process naturally occurring within the triatomine invertebrate host.
Abstract: The transformation of Trypanosoma cruzi epimastigotes to the mammal infective metacyclic trypomastigotes (metacyclogenesis) can be performed in vitro under chemically defined conditions Under these conditions, differentiating epimastigotes adhere to a surface before their transformation into metacyclic trypomastigotes Scanning and transmission electron microscopy of adhered and non-adhered parasites during the metacyclogenesis process show that only epimastigotes and few transition forms are found in the first population, whereas metacyclic trypomastigotes are exclusively found in the cell culture supernatant PAGE analysis of the [35S]methionine metabolic labeling products of adhered and non-adhered parasites shows that although most of the polypeptides are conserved, adhered parasites express specifically four polypeptides in the range of 45-50 kD with an isoelectric point of 48 These proteins might be involved in the adhesion process and are recognized by an antiserum against total adhered parasite proteins This antiserum also recognized a group of 45-50 kD in the iodine-radiolabeled surface proteins of differentiating cells, providing direct evidence that these components are indeed surface antigens The results suggest that epimastigotes must adhere to a substrate before their transformation to metacyclic trypomastigotes, being released to the medium as the metacyclogenesis process is accomplished This could correspond to the process naturally occurring within the triatomine invertebrate host
169 citations
TL;DR: The results strongly suggest that guanine nucleotide binding proteins are involved in T. cruzi adenylate cyclase activation and may be useful for studying cell differentiation mechanisms in eukaryotes.
110 citations
TL;DR: The results suggest that digestion starts in the lumen of posterior midgut and ends with the action of enzymes trapped between extracellular membranes or on the surface of midGut cells.
86 citations
TL;DR: Observations suggest that this is an area of recent established L. b.
Abstract: From July 1984 to September 1986, 105 cases of American cutaneous leishmaniasis were studied in a locality closely situated to an urbanized area of the city of Rio de Janeiro, Brazil. Settlement in this area was established at least 20 years ago but the first cases were noted six months prior to the beginning of this study. Cases were almost exclusively cutaneous and ulcerated, with one to six months of evolution. Montenegro's skin tests were positive in all cases and anti-Leishmania antibodies were detected by indirect immunofluorescence test in 74.3% of the patients. Parasites were demonstrated in 69.5% of cases. Domestic animals were easily found infected: 32% of the examined dogs and 30.8% of the examined equines were positive to the presence of Leishmania in cutaneous ulcerated lesions. Parasite isolates from human, dog and equines were immunologically characterized and identified as L. b. braziliensis. 73.0% of the sandfly population were Lutzomyia intermedia mainly caught on human baits and on domestic animals. Our observations suggest that this is an area of recent established L. b. braziliensis infection and that transmission probably occurs indoors or outdoors close to the houses.
81 citations
TL;DR: Results support the suggestion that macrophages participate in the control of neutrophil migration induced by acute inflammatory stimuli.
Abstract: Previous experiments of our group have shown that neutrophil migration induced by inflammatory stimuli is reduced by agents which block the release from macrophages of a specific factor for neutrophil migration (MNCF, [1, 2]). The present paper evaluated the influence of macrophage depletion induced by lavage of the peritoneal cavity on neutrophil migration. In both normal and thioglycollate-stimulated peritoneal cavities, lavage with saline reduced the resident macrophage population by about 80% and significantly blocked neutrophil migration induced by inflammatory stimuli such as carrageenin, zymosan and E. coli endotoxin. Peritoneal lavage, however, did not affect neutrophil migration induced by MNCF. Thus, these results support the suggestion that macrophages participate in the control of neutrophil migration induced by acute inflammatory stimuli.
76 citations
TL;DR: The results favor the view that oligomers derived from partial digestion of polymeric food are hydrolyzed down to monomers by enzymes trapped between microvillar membranes or on the surface of midgut cells.
75 citations
TL;DR: The rates of prevalence observed in Amazonas for both HBV and HDV are perhaps among the highest in the world, demonstrating that these viruses are endemic in this region of Brazil.
Abstract: Serum samples were non-randomly obtained from apparently healthy inhabitants of 5 villages in the Amazonas State, Brazil. Sera were tested by enzyme immunoassay for the presence of hepatitis B surface antigen (HBsAg) and, if this was found, for antibody to hepatitis delta virus (HDV). Of 574 people tested, 96 (16.7%) were reactive for HBsAg and 33 of these (34.4%) for anti-HDV. The results were analysed according to sex, age and history of jaundice and showed a high prevalence of hepatitis B virus (HBV) and HDV infections in these asymptomatic persons, mainly in young people. The rates of prevalence observed in Amazonas for both HBV and HDV are perhaps among the highest in the world, demonstrating that these viruses are endemic in this region of Brazil.
67 citations
TL;DR: An IgM capture test was applied with clear and reproducible results for diagnosis and evaluation of virus circulation; IgM antibodies appeared soon after start of clinical disease, and persisted for about 90 days in most patients.
Abstract: A dengue outbreak started in March, 1986 in Rio de Janeiro and spread very rapidly to other parts of the country. The great majority of cases presented classical dengue fever but there was one fatal case, confirmed by virus isolation. Dengue type 1 strains were isolated from patients and vectors (Aedes aegypti) in the area by cultivation in A. albopictus C6/36 cell line. The cytopathic effect (CPE) was studied by electron microscopy. An IgM capture test (MAC-ELISA) was applied with clear and reproducible results for diagnosis and evaluation of virus circulation; IgM antibodies appeared soon after start of clinical disease, and persisted for about 90 days in most patients. The test was type-specific in about 50% of the patients but high levels of heterologous response for type 3 were observed. An overall isolation rate of 46.8% (813 virus strains out of 1734 specimens) was recorded. The IgM test increased the number of confirmed cases to 58.2% (1479 out of 2451 suspected cases). The importance of laboratory diagnosis in all regions where the vectors are present is emphasized.
60 citations
TL;DR: The validity of Biomphalaria kuhniana (Clessin, 1883) is confirmed through morphological study of specimens from Surinam and the area of Tucurui and throught crossing experiments which revealed complete reproductive isolation between the two species.
Abstract: The validity of Biomphalaria kuhniana (Clessin, 1883) is confirmed through morphological study of specimens from Surinam (type locality) and the area of Tucurui (Tocantins river, state of Para, Brazil) in comparison with B. straminea (Dunker, 1848), and throught crossing experiments which revealed complete reproductive isolation between the two species. The full-grown shell of kuhniana is smaller (about 7.5 mm) than that of straminea (11 mm to 16.5 mm). Anatomically they differ in the degree of corrugation of the vaginal wall (little developed in kuhniana, conspicuous in straminea), number and shape of prostatic diverticula (kuhniana 4 to 9, shorter and less branched; straminea 9 to 18, longer and more branched),number of muscle layers at the middle of the penis (two in kuhniana, three in straminea), distal segment of the spermiduct usually straight or slightly wavy in kuhniana, more or less curly in straminea. Differences between B. kuhniana and B. intermedia (paraense & Deslandes, 1962) are less marked. The latter has a shell up to about 12 mm in diameter, 7 to 15 prostatic diverticula, two muscle layers at the middle of the penis, and a vaginal wall with a combination of a more or less developed corrugation (or sometimes a mere swelling) on the left of the spermathecal duct and a rudimentary pouch on the right of the duct. A Biomphalaria straminea complex is proposed to include that species as well as B. kuhniana and B. intermedia.
58 citations
TL;DR: It was observed that IF-IgM titers were significantly higher amongst the cutaneous leishmaniasis patients with less than four months of disease as compared to those with longer periods of disease and that IF -IgG titerswere significantly higher in patients with multiple lesions as compared with those with single lesions.
Abstract: The indirect immunofluorescence test (IF) for anti-Leishmania antibodies (IgG and IgM) was performed with sera from the following groups of individuals: 214 cutaneous leishmaniasis patients, 28 healthy subjects with positive Montenegro's skin test (MST), 29 healthy subjects with negative MST and 16 visceral leishmaniasis patients. The first four groups came from a suburban area of Rio de Janeiro (Jacarepagua) where cutaneous leishmaniasis caused by Leishmania braziliensis braziliensis is endemic. It was observed that IF-IgM titers were significantly higher amongst the cutaneous leishmaniasis patients with less than four months of disease as compared to those with longer periods and that IF-IgG titers were significantly higher in patients with multiple lesions as compared to those with single lesions. The visceral leishmaniasis patients had IF-IgG titers significantly higher than those from cutaneous leishmaniasis patients. A group of 28 individuals selected amongst the 214 cutaneous leishmaniasis patients had their IF-titers (IgG and IgM) compared to those of the two control groups of healthy subjects from the endemic area, respectively with positive and negative MST. Significantly higher titers of IF-IgG and IF-IgM were found in the group with active disease. The same group of patients showed IF-IgG titers significantly lower at the end of the antimonial therapy than those observed during this treatment.
TL;DR: The larvicidal properties of 34 plant extracts were tested against Aedes fluviatilis (Lutz) larvae, at 100, 10 and 1 ppm concentrations; 26,6% of the extracts enhanced larval mortality.
Abstract: The larvicidal properties of 34 plant extracts were tested against Aedes fluviatilis (Lutz) (Diptera: Culicidae) larvae, at 100, 10 and 1 ppm concentrations; 26.6% of the extracts enhanced larval mortality (alpha = 0.05) at 100 ppm (Anacardium occidentale, Agave americana, Allium sativum, Coriandrum sativum, Nerium oleander, Spatodea campanulata, Tibouchina scrobiculata and Vernonia salzmanni). Anacardic acid (A. occidentale) was effective at 10 ppm and A. sativum (crude extract) at 1 ppm.
TL;DR: The authors conclude that breast-feeding should not be avoided for children of chronic chagasic women, however, as these mothers had intermittent parasitemia, they should avoid nursing when there is nipple bleeding.
Abstract: On hundred milk or colostrum samples from 78 mothers with chronic Chagas' disease were parasitologically studied for Trypanosoma cruzi infection by means of direct examination and inoculation of mice. The mice were submitted to direct bllod examination three times a week. At the end of 45 days, xenodiagnosis and indirect immunofluorescent test (IFAT) for T. cruzi antibodies were carried out in the animals. No parasitized sample was observed even though five mothers had parasitemia at milk collection. In addition, 97 breast-fed children of chronic chagasic mothers, born free of infection, were tested for IgG antibodies to T. cruzi using IFAT. No case of T. cruzi infection was detected. The authors conclude that breast-feeding should not be avoided for children for chronic chagasic women. However, as these mothers had intermittent parasitemia, they should avoid nursing when there is nipple bleeding.
TL;DR: Standard and stabilized yellow fever vaccines were compared and the vaccine fulfilled WHO recommendations in inducing 100% serological conversion in volunteers given about 200 pfu or 600 LD50.
TL;DR: Ethanolic extracts of leaves from Potomorphe umbellata and Potomorfhe peltata, popularly said to have antimalarial capacity, were submitted to the 4-day suppressive test in Plasmodium berghei-infected mice and evidenced strong antimalaria activity.
TL;DR: The results indicate that a number of mouse TEC subsets can be distinguished by cytokeratin expression and can be applied to analyze TEC sensitivity to drugs and might also be useful to further understanding of differential TEC function regarding intrathymic T-cell differentiation.
Abstract: A major component of the thymic microenvironment is a network of thymic epithelial cells (TEC) which are able to express class II major histocompatibility complex products and to secrete thymic hormones. In the present investigation, we used a panel of anti-cytokeratin (CK) antibodies to establish distinct cytokeratin-defined TEC subsets. Four subpopulations were identified. One, in the cortex, is defined by anti-CK8 and anti-CK18 monoclonal antibodies (MAb). The other three subsets are medullary, two minor ones respectively reactive with anti-CK19 and KL1 monoclonal antibodies (the latter being specific for CK3 and 10), and a major one characterized by negative reaction with the above-mentioned MAb but strongly positive after labeling with a polyclonal (and polyspecific) anti-keratin immunoserum. Ontogenetic studies revealed that the CK8+/18+ TEC subset is the first to be detected in fetal life. Moreover, the numbers of CK3/10+ cells and CK19+ cells decrease in aging normal mice, a phenomenon that seems to occur early in autoimmune mice. We also observed that these two medullary TEC subsets are sensitive to high-dose in vivo treatment with hydrocortisone, which stimulates a dramatic increase in CK3/10+ cells and a certain decrease in CK19+ cells. Our results indicate that a number of mouse TEC subsets can be distinguished by cytokeratin expression. Such a strategy can be applied to analyze TEC sensitivity to drugs and might also be useful to further understanding of differential TEC function regarding intrathymic T-cell differentiation.
TL;DR: E examinada e comparada a reacao de nove especies vetoras da doenca de Chagas a infeccao, por sete diferentes cepas do T.cruzi, os dois ultimos grupos encontram mais frequentemente condicoes that lhes permitem maior convivencia com o homem e animais domesticos.
Abstract: E examinada e comparada a reacao de nove especies vetoras da doenca de Chagas a infeccao, por sete diferentes cepas do T.cruzi (Berenice, Y, FL, CL, Sao Felipe, Colombiana e Gavea). Com base na habilidade em estabelecer e manter a infeccao, as especies vetoras podem ser divididas em dois grupos distintos, que diferem em suas reacoes a infeccao aguda por T.cruzi. Enquanto a proporcao de insetos positivos foi baixa em domiciliados (Triatoma infestans e Triatoma dimidiata), foi alta nos considerados completamente selvagens (Rhodnius neglectus e Triatoma rubrovaria), ao serem iniciadas suas colonizacoes no laboratorio, no inicio da decada de 70, e nos essencialmente silvestres (Panstrongylus megistus, Triatoma sordida e Triatoma pseudomaculata). Admite-se que devido a exploracao agropecuaria e gracas as campanhas de controle, os dois ultimos grupos encontram mais frequentemente condicoes que lhes permitem maior convivencia com o homem e animais domesticos. As proporcoes de positivos nas cinco ultimas especies acima citadas, cada qual infectada com uma das sete cepas do T.cruzi, quando somadas (34 "Overalls") variam de 90% a 100%, com excecao de 65,6% encontrada em P.megistus infectado com a cepa Gavea. A posicao intermediaria esta sendo ocupada por Triatoma brasiliensis e Rhodniusprolixus, o ultimo alternando entre biotipo natural e artificial. Achado relevante foi a uniformidade de reacoes dos vetores silvestres as infeccoes com, praticamente, todas as cepas do T.cruzi, sugerindo que o fator ou fatores responsaveis pela reacao do P.megistus a infeccao pela cepa Y tambem operam nas reacoes desta especie com as restantes cepas, embora, varias destas tenham sido bioquimicamente diferentes entre si. A comparacao dos dados aqui apresentados com os relatados por outros investigadores, forma a base da discussao sobre a superioridade de uso do D.maximus como agente no xenodiagnostico.
TL;DR: Studies performed more than forty years ago in the Rondonia State indicated that the only important local vector of malaria was Anopheles darlingi, but since then, huge uncontrolled immigration, mostly from malaria free areas from Northeastern and Southern States, has been stimulated, leading to a marked increase in the incidence of malaria in Brazil.
Abstract: KEY WORDS: Malaria; Epidemiology; Rondonia State. Studies performed more than forty years ago in the Rondonia State, as well as in other scattered localities in the Amazon Basin indicated that the only important local vector of malaria was Anopheles darlingi -u Since then, huge uncontrolled immigration, mostly from malaria free areas from Northeastern and Southern States, has been stimulated and remarkable change in the environment has occured due to human activity, leading to a marked increase in the incidence of malaria in Brazil, reaching about 500 thousands cases in 1987, more than 40% of the patients being from Rondonia". Y. Recent investigations in another Amazonian State (Para)
TL;DR: Recurrences of the disease were clearly shown through the concurrence of recently-formed granulomas with oldergranulomas, implying that this type of granulomatous process does not eliminate the disease, nor is it able to limit fungal dissemination over a prolonged period of time.
Abstract: Female albino rats were used for the sequential histopathological study of experimental paracoccidioidomycosis. The animals were inoculated intraperitoneally with a strain of Paracoccidioides brasiliensis in the yeast-like phase, and sacrificed at given intervals from 1 to 168 days after inoculation; each animal received an inoculum of 4 x 106 cells in 0.8 ml of saline. The control group received saline containing scrapings of the culture medium.
Tissue from the inoculation site was examined. The cellular population, the extracellular matrix, and the presence and characteristics of fungi were analysed in the inflammatory granulomatous process by light microscopy.
The results allowed to separate the kinetic of the inflammatory response into three stages: 1) neutrophilic or macrophagic-neutrophilic; 2) pre-granulomatous; 3) granulomatous.
Synthesis of the extracellular matrix began with the depositing of fibrin-like material, and increased gradually with deposits of collagen, proteoglycans, and glycoproteins. Parasites were present in all of the examined periods.
Recurrences of the disease were clearly shown through the concurrence of recently-formed granulomas with older granulomas, implying that this type of granulomatous process does not eliminate the disease, nor is it able to limit fungal dissemination over a prolonged period of time.
TL;DR: The antibody response to trypanosoma cruzi epimastigote and trypomastigotes, as well as to laminin, was studied in several groups of chagasic patients as discussed by the authors.
Abstract: The antibody response to Trypanosoma cruzi epimastigote and trypomastigote stages, as well as to laminin, was studied in several groups of chagasic patients. In six patients who were cured of the parasite, the serum antibody titers as revealed by indirect immunofluorescence and hemagglutination tests against epimastigotes (conventional serology) and a complement-mediated lysis test with living trypomastigotes did not differ from those of normal individuals. In seven presumably cured patients, although the complement-mediated lysis test turned negative, conventional serology remained positive. Sera from this group of so-called "dissociated" patients presented significant lower mean antibody titers against epimastigote but not trypomastigote stages than did sera from 14 untreated patients (P less than 0.01). Most of the antibodies against trypomastigotes, including the residual levels found in cured patients, were absorbed by mouse laminin. In fact, significantly higher titers of anti-laminin antibodies were observed in sera from untreated chagasic patients (1.131 +/- 0.458) and cured patients (1.103 +/- 0.572) than in sera from eight normal individuals (0.459 +/- 0.402) (P less than 0.01). The anti-laminin titers were higher in sera of patients of blood group A or O than in those of patients of group B or AB. In Western blotting (immunoblotting) analysis against trypomastigotes, sera from chronic untreated patients recognized many polypeptide bands ranging from 26 to 160 kilodaltons, whereas no protein bands were observed with sera from cured patients. Only faint bands of parasite proteins were observed with sera of dissociated patients. In conjunction, the above data suggest that the anti-trypomastigote antibodies which persist after parasitological cure of patients with Chagas' disease are due mainly to cross-reactive epitopes from mouse laminin.
TL;DR: Monogenetic insect trypanosomatids of the genera Crithidia, Leptomonas and Herpetomonas multiplied as in axenic cultures, for many months, in the lumen of the scent glands of the opossum Didelphis marsupialis.
Abstract: Monogenetic insect trypanosomatids of the genera Crithidia, Leptomonas and Herpetomonas, multiplied as in axenic cultures, for many months, in the lumen of the scent glands of the opossum Didelphis marsupialis. Specific antibodies were detected in the serum of the animals but there was no evidence of invasion of their tissues by the parasites.
TL;DR: Clinical, histopathological, and serological findings were similar to what is found in natural canine infection as well as in the human disease, suggesting dogs may be an useful model for L. b.
Abstract: Four mongrel dogs were intradermically inoculated with 3 x 10**6 Leishmania braziliensis braziliensis promastigotes. Three out of the four animals developed cutaneous lesions respectively 4, 7, and 8 months after. The fourth dog did not develop lesion at the inoculation site, but a mucosal ulcer was seen 16 months after the inoculum. Clinical, histopathological, and serological findings were similar to what is found in natural canine infection as well as in the human disease. These results suggest that dogs may be an useful model for L. b. braziliensis infection.
TL;DR: In vitro experiments confirmed the data observed in vivo demonstrating that the increase in KL1+ cells is a direct effect of hydrocortisone on TEC, demonstrating that glucocorticoid hormone can act on T EC modulating the expression of both secretory and cytoskeletal protein families.
Abstract: The thymic epithelium, a major component of the thymic microenvironment, is a heterogeneous tissue bearing distinct monoclonal antibody-defined subsets. Among these, KL1+ cells represent a mouse medullary subpopulation characterized by high mol wt cytokeratin expression. Given the fact that thymic epithelial cells (TEC) express glucocorticoid receptors and that glucocorticoid hormones are known to modulate the expression of keratins, we decided to study the in vivo effects of hydrocortisone on KLl+ cells in normal and autoimmune mice. Within 24 h after a single injection of this steroid we observed a significant increase in the number of KL1+ cells. Interestingly, this effect was reversible and was no longer detected 7 days after treatment. Parallel studies analyzing the effects of hydrocortisone on the secretion of thymulin, a chemically defined thymic hormone revealed a transient decrease in serum levels of this hormone, but with different kinetics than the effects on KL1+ cells. Ontogenetic studies sho...
TL;DR: The data show that self-fertilization is not so efficient an alternative mode of reproduction in H. duryi as in many other planorbids, and the species benefits much less from functional hermaphroditism which, besides other advantages, enables a single virgin individual to found a new population.
Abstract: Fifty specimens of five strains (10 per strain) of Helisoma duryi from Lima (Peru), St Croix (Virgin Islands), Formosa (Brazil), Cartago (Costa Rica) and St Vincent (Lesser Antilles), reared in isolation for about 150 days, laid 103 eggs The numbers of eggs laid by the 10 specimens of each strain were respectively (viable eggs in parenthesis): 44(26), 1 (1), 5(0), 15 (7) and 38 (0) Egg production widely varied between the individuals of each strain, there being in all strains,except St Vincent, a number of specimens (3 to 9) which did not lay any eggs After the observation period the isolated specimens, including those that laid no eggs, readily engaged in cross-breeding when mated and brought forfh large numbers of eggs Self-fertilized F 1s are fully interfertile, producing normal cross-fertilized offspring Ten specimens of Helisoma trivolvis (strain from Zempoala, Mexico), also reared in isolation for about 120 days, laid 646 eggs, of which 74 were inviable our data, added to those from a few ´revious studies cited in the text, show that self-fertilization is not so efficient an alternative mode of reproduction in H duryi as in many other planorbids (it is a little more efficient in H trivolvis than in H duryi) Thus, H duryi benefits much less from functional hermaphroditism which, besides other advantages, enables a single virgin individual to found a new population
Journal Article•
TL;DR: Results are strongly suggestive that the Gal/GalNAc recognition system of the macrophages is involved in the interiorization of T. cruzi.
TL;DR: Triatoma vitticeps seems to be a poor transmissor of T. cruzi, held under laboratory conditions and fed weekly in mice, and its resistance to starvation is evaluated.
Abstract: Observations were made on the evolutive cycle of Triatoma vitticeps, held under laboratory conditions and fed weekly in mice. Of the 435 eggs obtained, from 4 virgen couples, 149 were purposed for the biological cycle study and 286 to evaluate their resistance to starvation, which shall be a second part of this work. Only 50 specimens reached the adult stage in a period of X (S) = 270 ± 45 days. At the incubation time, the first and second instars were of less than a month for each, while the third, fourth and fifth instars requires approximately one, two and three months, respectively. The search for the first meal occured clearly on the 3rd, 6th and 10th day. During all the stages,more than 50% of the specimens had only one blood-meal, except the fifth one, when two blood-meals were required. In relation to the time-lapse between the presenting of the blood-meal and the beginning of feeding, as well as the length of the blood-meal, it was observed that these increased gradually according to the stage. From the 423 blood-meals performed, 390 were not followed by defecation in the settled period of 10 min. Under this point of view, t. vitticeps seems to be a poor transmissor of T. cruzi. The experiment was carried out for 13 months and by this time the averages of minimum and maximum temperatures and the humidity were 25 ± 2°C - 28 ± 2°C and 80 ± 2%, respectively. The material belongs to the triatomine colony held at the Oswaldo Cruz Institute, Department of Entomology.
TL;DR: Pimelodus ortmanni is a new host record for P. peraccurants and S. intermedius, and three species of nematodes were recovered from 83 specimens of 12 species of fishes from the reservoir of "Salto Santiago".
Abstract: Eight species of nematodes and one larval cestode were recovered from 88 specimens of 12 species of fishes captured in the reservoir of "Salto Osorio". Capillaria sp., Contracoecum sp., (larval forms), Procamallanus peraccuratus pinto et al., 1976, Procamallanus petterae Kohn & Fernandes, 1988, Raphidascaris sp., Spirocamallanus intermedius Pinto et al., 1974 and Spirocamallanus pintoi Kohn & Fernandes, 1988. From 83 specimens of 12 species of fishes from the reservoir of "Salto Santiago", only one species of cestode and three species of nematodes were recovered: Contracoecum sp. (larval forms), procamallanus peraccuratus and Raphidascaris sp. Pimelodus ortmanni is a new host record for P. peraccurants and S. intermedius.