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1.
Braz. j. biol ; 76(4): 884-887, Oct.-Dec. 2016. graf
Article in English | LILACS | ID: biblio-828101

ABSTRACT

Abstract The present study reports the first case of the presence of the intestinal nematode Strongyloides sp. in fecal examinations of a male Lutreolina crassicaudata, considered a synanthropic marsupial species with zoonotic potential. The Willis technique was used for the diagnosis. Presence of typical eggs of Strongyloides species in feces was detected. A fecal culture was performed to obtain larval stages, free-living adults and infective third stage larvae (L3) of this nematode after seven days, which was morphologically identified as Strongyloididae. This is the first report of infection by Strongyloides sp. in a tick-tailed opossum from Brazil.


Resumo O presente estudo relata o primeiro registro da presença do nematódeo intestinal Strongyloides sp. em exames de fezes de um macho de Lutreolina crassicaudata, considerado um marsupial sinantrópico com potencial zoonótico. A técnica de Willis foi empregada no diagnóstico. Presença de ovos típicos de Strongyloides spp. foi detectada nas fezes. Uma coprocultura foi realizada para obtenção de estágios larvais, adultos de vida livre e larvas infectantes de terceiro estágio (L3) deste nematódeo após sete dias, os quais foram identificados morfologicamente como Strongyloididae. Este é o primeiro relato de infecção por Strongyloides sp. em uma cuíca de cauda grossa do Brasil.


Subject(s)
Animals , Opossums/parasitology , Parasitic Diseases, Animal/parasitology , Strongyloides/isolation & purification , Strongyloidiasis/veterinary , Brazil , Feces/parasitology , Larva
2.
Braz. j. infect. dis ; 20(2): 119-126, Mar.-Apr. 2016. tab
Article in English | LILACS | ID: lil-780799

ABSTRACT

Abstract A population survey was conducted to explore the prevalence and factors associated with Leishmania infection in the Fercal region of the Federal District. The Fercal region is a group of neighborhoods in Brasília in which the first cases of visceral leishmaniasis were described. Leishmania infection was established by a positive leishmanin test. Although other tests were performed in the study (an immunochromatographic assay (Kalazar detect®) and a molecular assay), only the leishmanin skin test provided sufficient results for the measurement of the disease prevalence. Data on the epidemiological, clinical and environmental characteristics of individuals were collected along with the diagnostic tests. After sampling and enrollment, seven hundred people from 2 to 14 years of age were included in the study. The prevalence of Leishmania infection was 33.28% (95% CI 29.87–36.84). The factors associated with Leishmania infection according to the multivariate analysis were age of more than seven years and the presence of opossums near the home. Age is a known factor associated with Leishmania infection; however, the presence of wild animals, as described, is an understudied factor. The presence of opossums, which are known reservoirs of Leishmania, in peri-urban areas could be the link between the rural and urban occurrence of visceral leishmaniasis in the outskirts of largest Brazilian cities, as suggested by previous studies.


Subject(s)
Humans , Animals , Male , Female , Child, Preschool , Child , Adolescent , Opossums/parasitology , Disease Reservoirs/parasitology , Asymptomatic Infections , Leishmaniasis, Visceral/epidemiology , Brazil/epidemiology , Prevalence , Cross-Sectional Studies , Risk Factors , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/transmission
3.
Article in English | LILACS, VETINDEX | ID: biblio-875135

ABSTRACT

South American opossums are the definitive hosts of Sarcocystis neurona, Sarcocystis falcatula, Sarcocystis speeri and Sarcocystis lindsayi. The sporocysts of these species of Sarcocystis are morphologically similar and methods like infectivity and pathogenicity for intermediate hosts (immunodeficient mice and psittacine birds) and molecular tools are used for identification. Opossums are synanthropic wild animals, and widely distributed in Brazilian territory. Previous studies have shown high environmental contamination with S. neurona sporocysts in several Brazilian regions. This paper reviews information on Sarcocystis spp. shed by various opossum species and its occurrence in Brazil.(AU)


Os gambás Sul-americanos são os hospedeiros definitivos de Sarcocystis falcatula, Sarcocystis neurona, Sarcocystis speeri e Sarcocystis lindsayi. Estas espécies de Sarcocystis são morfologicamente similares, mas podem ser distinguidas por sua patogenicidade e infectividade em hospedeiros intermediários (aves e camundongos imunodeficientes) e técnicas moleculares. Os gambás são animais silvestres e sinantrópicos e amplamente distribuídos no território nacional. Estudos anteriores demonstraram uma alta contaminação ambiental com esporocistos de S. neurona em diversas regiões brasileiras. Este artigo revisa informações sobre Sarcocystis spp. excretados por gambás e sua ocorrência no Brasil.(AU)


Subject(s)
Animals , Didelphis/parasitology , Opossums/parasitology , Parasite Egg Count/veterinary , Sarcocystis/parasitology , Sarcocystis/pathogenicity , Brazil
4.
Cad. saúde pública ; 30(4): 746-756, abr. 2014. tab, graf
Article in Spanish | LILACS | ID: lil-711201

ABSTRACT

Colombia tiene un registro de 11 casos de Chagas agudo y 80 casos por contaminación oral con Trypanosoma cruzi. Este trabajo analiza los hallazgos entomológicos y parasitológicos del brote de Aguachica, Cesar, en 2010. Un grupo interdisciplinario de profesionales de la salud y de universidades regionales realizó las pruebas de laboratorio a los pacientes y el estudio del foco de transmisión. Se detectaron 11 casos agudos de enfermedad de Chagas en una sola familia con vivienda sin triatominos domiciliados y, Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus y dos Didelphis marsupialis infectados con T. cruzi en palmas de Attalea butyracea y Elaeis oleifera del área urbana de Aguachica. Se analiza la participación del R. pallescens y el rol de las palmas en el ciclo silvestre de T. cruzi y para la transmisión oral de la enfermedad de Chagas. Incursiones esporádicas de R. pallescens, P. geniculatus y E. cuspidatus silvestres desde palmas cercanas al domicilio humano pueden provocar brotes cada vez más frecuentes de Chagas oral.


Colombia recorded 11 cases of acute Chagas disease and 80 cases of oral contamination with Trypanosoma cruzi. The current study analyzes the entomological and parasitological characteristics of the outbreak in Aguachica, Cesar Department, in 2010. An interdisciplinary group of health professionals and regional university personnel conducted the laboratory tests in the patients and the investigation of the transmission focus. Eleven cases of acute Chagas diseases were detected in a single family in a dwelling with domiciliated triatomines and Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus, and two Didelphis marsupialis opossums infected with T. cruzi in Attalea butyracea and Elaeis oleifera palm trees in the urban area of Aguachica. The study analyzes the role of R. pallescens and palm trees in the wild cycle of T. cruzi and in oral transmission of Chagas disease. Sporadic incursions by wild R. pallescens, P. geniculatus, and E. cuspidatus from the nearby palm trees into human dwellings may cause increasingly frequent outbreaks of oral Chagas disease.


A Colômbia tem registro de 11 surtos da doença de Chagas e 80 casos agudos por contaminação oral com Trypanosoma cruzi. Esta pesquisa analisa os achados entomológicos e parasitológicos do surto de Aguachica, Cesar, em 2010. Um grupo interdisciplinar de profissionais da saúde e de universidades regionais efetuou os testes laboratoriais nos pacientes e o estudo de foco de transmissão. Encontraram 11 casos agudos da doença de Chagas em uma única família com domicilio sem triatomíneos e Rhodnius pallescens, Pantrongylus geniculatus, Eratyrus cuspidatus e dois Didelphis marsupialis infectados com T. cruzi em palmeiras de Attalea butyracea e Elaeis oleifera da área urbana de Aguachica. Analisa-se a participação de R. pallescens e a função das palmeiras em o ciclo silvestre de T. cruzi e para a transmissão oral da doença de Chagas. Incursões esporádicas de R. pallescens, P. geniculatus e E. cuspidatus silvestres das palmeiras próximas ao domicilio humano podem provocar surtos cada vez mais frequentes de Chagas oral.


Subject(s)
Adolescent , Adult , Aged , Animals , Child , Humans , Middle Aged , Young Adult , Chagas Disease/epidemiology , Chagas Disease/transmission , Disease Outbreaks , Trypanosoma cruzi/isolation & purification , Acute Disease , Arecaceae/parasitology , Colombia/epidemiology , Disease Reservoirs/parasitology , Insect Vectors/parasitology , Opossums/parasitology , Triatominae/parasitology
5.
Rev. bras. parasitol. vet ; 22(1): 152-154, Jan.-Mar. 2013. tab
Article in English | LILACS, VETINDEX | ID: lil-671626

ABSTRACT

The aim of this paper is to record new hosts for Ixodes luciae Sénevet in the State of Para, Brazil, and present a case of malformation (teratogeny) in a nymph of this species. The new host records are Marmosa murina (parasitized by females) and Philander opossum (parasitized by nymphs). One of these nymphs showed malformation in the posterior margin of the opisthosoma resulting in a heart shaped posterior end.


O objetivo deste trabalho foi registrar novos hospedeiros para Ixodes luciae Sénevet no estado do Pará, Brasil, e um caso de malformação em uma ninfa dessa espécie de carrapato. Os novos hospedeiros são Marmosa murina (parasitado por fêmeas) e Philander opossum (parasitado por ninfas). Uma dessas ninfas apresentou uma malformação na parte posterior do opistossoma em forma de coração.


Subject(s)
Animals , Male , Female , Ixodidae/physiology , Opossums/parasitology , Teratogenesis , Brazil , Nymph
6.
Biomédica (Bogotá) ; 32(2): 196-205, abr.-jun. 2012. ilus, tab
Article in Spanish | LILACS | ID: lil-656828

ABSTRACT

Introducción. La enfermedad de Chagas, causada por Trypanosoma cruzi, es uno de los problemas más graves de salud pública en el continente americano. El benzonidazol es uno de los dos medicamentos utilizados para tratar la enfermedad de Chagas. Sin embargo, la variación de la sensibilidad del parásito a este medicamento es una de las principales causas del fracaso del tratamiento. Objetivo. Evaluar la sensibilidad in vitro al benzonidazol de cepas colombianas de T. cruzi de diferentes orígenes y procedencia geográfica. Materiales y métodos. Treinta y tres cepas colombianas de T. cruzi aisladas de humanos, vectores y mamíferos, se analizaron in vitro mediante el micrométodo enzimático de MTT para determinar la concentración inhibitoria 50 (CI50) al benzonidazol. Se estudió la correlación entre la sensibilidad in vitro al medicamento y diferentes parámetros biológicos y eco-epidemiológicos. Resultados. El análisis de sensibilidad al medicamento indicó que el 36 % de las cepas eran sensibles, el 48 %, parcialmente resistentes y, el 16 %, resistentes al benzonidazol. Los análisis de correlación entre las CI50 con algunos parámetros biológicos y eco-epidemiológicos, mostraron diferencias en cuanto a la sensibilidad según el origen biológico y el área geográfica de procedencia de la cepa. Conclusiones. Existe una gran variabilidad en cuanto a la sensibilidad al benzonidazol de las cepas circulantes de T. cruzi en Colombia, lo cual sugiere la presencia de cepas naturalmente resistentes en el país.


Introduction. Chagas disease caused by Trypanosoma cruzi is one of the most serious public health problems in the Americas. Benznidazole is one of two drugs used to treat Chagas´ disease. However, the variation in susceptibility of the parasite to this drug is one of the main causes of treatment failure. Objective. The in vitro susceptibility to benznidazole was assessed in Colombian strains of T. cruzi from several sources and geographical regions. Materials and methods. Thirty-three Colombian T. cruzi strains were isolated from humans, vectors and mammals. These were analyzed in vitro by the MTT enzymatic micromethod to determine the IC50 to benznidazole. Additionally, the in vitro susceptibility was correlated with several biological and ecoepidemiological parameters. Results. Thirty-six percent of the strains were considered to be sensitive, 48% partially resistant, and 16% were resistant. Correlations between the IC50 and several biological and eco-epidemiological parameters indicated that differences in susceptibility depended on the biological source and geographical origin of the strain. Conclusions. A high degree of variability exists in the susceptibility to benznidazole of T. cruzi strains in Colombia. The distribution data indicate the presence and circulation of naturally resistant strains.


Subject(s)
Animals , Humans , Rats , Nitroimidazoles/pharmacology , Trypanocidal Agents/pharmacology , Trypanosoma cruzi/drug effects , Chagas Disease/epidemiology , Chagas Disease/parasitology , Chagas Disease/veterinary , Colombia/epidemiology , Drug Resistance , Ecology , Insect Vectors/parasitology , Opossums/parasitology , Panstrongylus/parasitology , Rhodnius/parasitology , Rodent Diseases/parasitology , Species Specificity , Triatoma/parasitology , Trypanosoma cruzi/isolation & purification
7.
Rev. bras. entomol ; 53(2): 314-317, June 2009. mapas
Article in English | LILACS | ID: lil-521146

ABSTRACT

The prevalence of Cuterebra simulans bot fly parasitism on marsupial Gracilinanus microtarsus was compared between sexes and seasons of the year. No significant difference was observed between females and males but prevalence was higher in warm-wet season than cool-dry season. This pattern agree with observations of others studies with oestrids flies in southern Neotropical areas, suggesting the occurrence of latitudinal change in the peak of bot flies reproductive activity related to seasons of the year along these systems. This is the first record of C. simulans larvae parasitism on G. microtarsus and its occurrence in southern areas of the Neotropical region.


A prevalência de parasitismo das larvas da mosca Cuterebra simulans no marsupial Gracilinanus microtarsus foi comparada entre os sexos e estações do ano. Machos e fêmeas não apresentaram diferenças significativas, mas a prevalência de parasitismo foi mais elevada na estação quenteúmida que na estação fria-seca. Este padrão está de acordo com as observações de outros estudos com moscas da família Oestridae realizados nas áreas ao sul da região Neotropical, sugerindo a ocorrência de mudanças latitudinais nos picos de atividades reprodutivas destas moscas em relação às estações do ano ao longo destes sistemas. Este também é o primeiro registro da ocorrência de C. simulans em áreas mais ao sul da região Neotropical e do parasitismo de suas larvas em G. microtarsus.


Subject(s)
Animals , Male , Female , Diptera/physiology , Opossums/parasitology , Hypodermyiasis , Myiasis , Brazil , Grassland , Larva
8.
Rev. bras. parasitol. vet ; 17(3): 158-160, jul.-set. 2008.
Article in Portuguese | LILACS | ID: lil-614857

ABSTRACT

Este é primeiro relato da ocorrência de Ixodes no Estado do Mato Grosso do Sul e primeiro caso identificado de Ixodes loricatus Neumann, 1899, parasitando Didelphis albiventris no município de Campo Grande, MS, Brasil.


This is first report of occurence of Ixodes in the State of Mato Grosso do Sul and first description of Ixodes loricatus Neumann, 1899, parasitizing Didelphis albiventris in Campo Grande, MS, Brazil.


Subject(s)
Animals , Ixodes/physiology , Opossums/parasitology , Brazil
9.
Rev. Soc. Bras. Med. Trop ; 40(4): 391-396, jul.-ago. 2007. ilus, mapas, tab
Article in English | LILACS | ID: lil-460241

ABSTRACT

Impact of the vector control program was evaluated eight years after implantation of epidemiological surveillance for ChagasÆ disease in Berilo, a municipality in the Jequitinhonha Valley of the Brazilian State of Minas Gerais. In all 5,242 domiciliary units (96 percent of the total) were inspected and 10 found to be infested by the triatomine bug Triatoma pseudomaculata. Triatomines were found associated with bats inside one house and in the peridomiciles of the other nine. None of the 111 Triatoma pseudomaculata captured was infected with Trypanosoma cruzi. Noireau et al16 traps were installed in (n=8) and around (n=100) the infested house but no Trypanpsoma cruzi-infected triatomines were found. None bat, opossums (Didelphis albiventris) and rat captured in the peridomicile were infected with Trypanosoma cruzi although 24 percent of the inhabitants of the house infested by Triatoma pseudomaculata were seropositive for the parasite, based on ELISA, IHA and IIF.


Oito anos após a implantação da vigilância epidemiológica para doença de Chagas em Berilo, Vale do Jequitinhonha, MG, Brasil, foi realizada uma pesquisa para verificar o impacto do Programa de Controle Vetorial. Neste trabalho, 5. 242 (96 por cento) unidades domiciliares foram vistoriadas. Dez estavam infestadas por Triatoma pseudomaculata. Em nove delas os insetos estavam infestando o peridomicílio e em uma casa foi constatado um foco intradomiciliar associado a morcegos. Foram capturados 111 insetos da espécie Triatoma pseudomaculata e nenhum exemplar estava infectado por Trypanosoma cruzi. Na casa infestada e em torno dela foram instaladas respectivamente 8 e 100 armadilhas de Noireau et al16 e nenhum triatomíneo foi capturado. Oitenta morcegos capturados e examinados também estavam negativos para Trypanosoma cruzi bem como três gambás (Didelphis albiventris) e um roedor, todos capturados no peridomicílio. Um porcentual de 24 por cento dos moradores das casas infestadas por Triatoma pseudomaculata foi sororeativo (ELISA, HAI e IFI) para Tripanosoma cruzi.


Subject(s)
Adolescent , Adult , Animals , Female , Humans , Middle Aged , Rats , Disease Reservoirs , Housing , Insect Vectors , Triatoma , Trypanosoma cruzi/isolation & purification , Brazil/epidemiology , Chagas Disease/diagnosis , Chagas Disease/epidemiology , Chagas Disease/transmission , Chiroptera/parasitology , Opossums/parasitology , Population Density , Population Surveillance , Prevalence
11.
Mem. Inst. Oswaldo Cruz ; 100(5): 471-473, Aug. 2005. mapas
Article in English | LILACS | ID: lil-409962

ABSTRACT

In Brazil, the colonization of human dwellings by triatomines occurs in areas with native vegetation of the caatinga or cerrado types. In areas of Atlantic forest such as in the Brazilian state of Espírito Santo, there are no species adapted to live in human habitations. The few autochthonous cases of Chagas disease encountered in Espírito Santo have been attributed to adult specimens of Triatoma vitticeps that invade houses from forest remnants. In recent years, the entomology unit of the Espírito Santo State Health Secretariat has recorded nymphs infected with flagellates similar to Trypanosoma cruzi in rural localities. Entomological surveys were carried out in the residences and outbuildings in which the insects were found, and serological examinations for Chagas disease performed on the inhabitants. Four colonies were found, all associated with nests of opossums (Didelphis aurita), 111 specimens of T. vitticeps, and 159 eggs being collected. All the triatomines presented flagellates in their frass. Mice inoculated with the faeces presented trypomastigotes in the circulating blood and groups of amastigotes in the cardiac muscle fibres. Serological tests performed on the inhabitants were negative for T. cruzi. Even with the intense devastation of the forest in Espírito Santo, there are no indications of change in the sylvatic habits of T. vitticeps. Colonies of this insect associated with opossum nests would indicate an expansion of the sylvatic environment into the peridomicile.


Subject(s)
Humans , Animals , Mice , Insect Vectors/parasitology , Triatoma/parasitology , Trypanosoma cruzi/isolation & purification , Brazil , Chagas Disease/diagnosis , Chagas Disease/transmission , Nymph , Opossums/parasitology , Rural Population , Trees
12.
Rev. Soc. Bras. Med. Trop ; 36(2): 241-248, mar.-abr. 2003. ilus
Article in English | LILACS | ID: lil-340903

ABSTRACT

Philander frenata and Didelphis marsupialis harbor parasitism by Trypanosoma cruzi without developing any apparent disease and on the contrary to D. marsupialis, P. frenata maintains parasitism by T. cruzi II subpopulations. Here we compared the humoral immune response of the two didelphids naturally and experimentally infected with T. cruzi II group, employing SDS-PAGE/Western blot techniques and by an Indirect immunofluorescence assay. We also studied the histopathological pattern of naturally and experimentally infected P. frenata with T. cruzi. P. frenata sera recognized more antigens than D. marsupialis, and the recognition pattern did not show any change over the course of the follow up of both didelphid species. Polypeptides of 66 and 90kDa were the most prominent antigens recognized by both species in the soluble and enriched membrane fractions. P. frenata recognized intensely also a 45kDa antigen. Our findings indicate that: 1) there were no quantitative or qualitative differences in the patent or subpatent phases in the recognition pattern of P. frenata; 2) the significant differences in the recognition pattern of parasitic antigens by P. frenata and D. marsupialis sera suggest that they probably "learned" to live in harmony with T. cruzi by different strategies; 3) although P. frenata do not display apparent disease, tissular lesions tended to be more severe than has been described in D. marsupialis; and 4) Both didelphids probably acquired infection by T. cruzi after their evolutionary divergence


Subject(s)
Animals , Humans , Antibodies, Protozoan/biosynthesis , Chagas Disease/veterinary , Opossums/parasitology , Trypanosoma cruzi/physiology , Antibodies, Protozoan/blood , Antigens, Protozoan/immunology , Blotting, Western , Brazil , Chagas Disease/immunology , Chagas Disease/pathology , Disease Models, Animal , Disease Reservoirs , Fluorescent Antibody Technique, Indirect , Host-Parasite Interactions , Trypanosoma cruzi/immunology
13.
Mem. Inst. Oswaldo Cruz ; 96(2): 265-71, Feb. 2001. ilus, tab
Article in English | LILACS | ID: lil-281578

ABSTRACT

Tetratrichomonas didelphidis (Hegner & Ratcliffe, 1927) Andersen & Reilly, 1965 is a flagellate protozoan found in the intestine, cecum, and colon of Didelphis marsupialis. The parasitic protozoa used in this study was found and isolated in the intestine of opossums in Pavlova starch-containing medium in Florianópolis, State of Santa Catarina, Brazil, from D. marsupialis and Lutreolina crassicaudata. The strains were cultivated in Diamond medium without maltose and with starch solution, pH 7.5 at 28§ C. The specimens were stained by the Giemsa method and Heidenhain's iron hematoxylin. The light microscopy study of the trophozoites revealed the same morphologic characteristics as specimens previously described


Subject(s)
Animals , Opossums/parasitology , Trichomonas/isolation & purification , Azure Stains , Intestines/parasitology , Trichomonas/classification , Trichomonas/ultrastructure
14.
Mem. Inst. Oswaldo Cruz ; 95(6): 795-800, Nov.-Dec. 2000. mapas, tab
Article in English | LILACS | ID: lil-273433

ABSTRACT

Between 1984 and 1993 the prevalence of the Trypanosoma cruzi infection in opossums (Didelphis marsupialis) was studied in Santa Catarina and Arvoredo Islands, State of Santa Catarina, Brazil. The association of the triatomine bug Panstrongylus megistus with opossums nests and the infection rate of these triatomines by T. cruzi was also studied. Thirteen different locations were studied in Santa Catarina Island (SCI), in which 137 D. marsupialis were collected. Sixty two opossums were collected at the Arvoredo Island (AI), located 12 miles north from SCI. All captured animals were submitted to parasitological examinations that revealed the presence of T. cruzi in 21.9 percent of the opossums captured in SCI and 45.2 percent among opossums captured in the AI. The presence of P. megistus was detected in most of the D. marsupialis nests collected in the SCI, however, in the non-inhabited AI only eight triatomines were collected during the whole study. The presence of T. cruzi-infected D. marsupialis associated with P. megistus in human dwellings in the SCI, and the high infection rate of D. marsupilais by T. cruzi in the absence of a high vector density are discussed


Subject(s)
Animals , Male , Female , Humans , Chagas Disease/epidemiology , Opossums/parasitology , Trypanosoma cruzi/isolation & purification , Brazil/epidemiology , Disease Reservoirs , Insect Vectors/parasitology , Panstrongylus/parasitology , Prevalence
16.
Parasitol. día ; 23(3/4): 121-2, jul.-dic. 1999.
Article in English | LILACS | ID: lil-258106

ABSTRACT

Tetratrichomonas didelphidis (Hegner and Ratcliffe, 1927) Andersen and Reilly, 1965 is a flagellate protozoan from the intestine, cecum, and colon of didelphis marsupialis Linnaeus, 1758. The parasite was found and isolated in the rectal glands in Pavlova starch-containing media in Florianópolis, SC, Brasil from D. marsupialis


Subject(s)
Animals , In Vitro Techniques , Opossums/parasitology , Trichomonadida/physiology , Culture Media/analysis , Eukaryota
17.
Mem. Inst. Oswaldo Cruz ; 94(3): 371-6, May-Jun. 1999. graf
Article in English | LILACS | ID: lil-239046

ABSTRACT

Philander opossum and Didelphis marsupialis considered the most andcient mammals and an evolutionary success, maintain parasitism by Trypanosoma cruzi without developing any apparent disease or important tissue lesion. In order to elucidate this well-balanced interaction, we decided to compare the humoral immune response kinetics of the two didelphids naturally and experimentally infected with T. cruzi and immunized by different shedules of parasite antigens, employinbg an indirect fluorescence antibody test (IFAT). Both didelphids responded with high serological titers to different immuniztion routes, while the earliest response occurred with the intradermic route. Serological titers of naturally infected P. opossum showed a significant individual variation, while those of D. marsupialis remained stable during the entire follow-up period. The serological titers of the experimentally infected animals varied according to the inoculated strain. Our data suggest that (1) IFAT was sensitive for follow-up of P. opossum in natural and experimental T. cruzi infections; (2) both P. opossum and D. marsupialis are able to mount an efficient humoral immune response as compared to placental mammals; (3) experimentally infected P. opossum and D. marsupialis present distinct patterns of infection, depending on the subpopulation of T. cruzi, (4) the differences observed in the humoral immune responses between P. opossum and D. marsupialis, probably, reflect distinct strategies selected by these animals during their coevolution with T. cruzi.


Subject(s)
Animals , Antibody Formation , Chagas Disease/immunology , Opossums/immunology , Opossums/parasitology , Immunoelectrophoresis , Host-Parasite Interactions , Trypanosoma cruzi
18.
Mem. Inst. Oswaldo Cruz ; 92(3): 343-51, May-Jun. 1997. ilus, mapas, tab, graf
Article in English | LILACS | ID: lil-189305

ABSTRACT

Thrity-five Trypanosoma cruzi strains were isolated from chronic chagasic triatomines and opossums from different municipalities of the State of Rio Grande do Sul. Parasites were characterized by means of mice infectivity, enzyme electrophoresis and randomly amplified polymorphic DNA (RAPD) analysis. Twenty-nine strains were isolated from chagasic patients, 4 from triatomines (2 from Triatoma infestans and 2 from Panstrongylus megistus) and 2 from opossums Didelphis albiventris. Thirty-three T. cruzi strains were of low and 2 strains of high virulence in mice. Both virulent strains were isolated from P. megistus. Isoenzyme analysis of the strains showed 3 different zymodemes. Eleven strains islolated from chagasic patients and 2 from D. albiventris were Z2. Eighteen strains from patients and 2 from T. infestans were ZB and 2 T. cruzi strains isolated from P. megistus were Z1. RAPD profiles obtained with 4 random primers showed a high genetic heterogeneity of T. cruzi strains. Zymodeme 2 and Zb strains were the more polymorphic. A band sharing analysis of the RAPD profiles of Z2 and ZB strains using 3 primers, showed a very low percentage of shared bands, 20 per cent among 13 ZB strains and 14 per cent among 13 Z2 strains. According to the isoenzyme results, 3 T. cruzi populations were present in State of Rio Grande do Sul. Zymodeme 2 and ZB strains were found infecting man (domiciliar transmission cycle) whereas Z1 strains were found infecting the sylvatic vector P. megistus.


Subject(s)
Humans , Animals , Trypanosoma cruzi/isolation & purification , Brazil , Chagas Disease/parasitology , Opossums/parasitology , Random Amplified Polymorphic DNA Technique , Triatominae/parasitology
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