RESUMO
Trypanosoma cruzi I, a discrete typing unit (DTU) found in human infections in Venezuela and other countries of the northern region of South America and in Central America, has been recently classified into five intra-DTU genotypes (Ia, Ib, Ic, Id, Ie) based on sequence polymorphisms found in the spliced leader intergenic region. In this paper we report the genotype identification of T. cruzi human isolates from one outbreak of acute orally acquired Chagas disease that occurred in a non-endemic region of Venezuela and from T. cruzi triatomine and rat isolates captured at a guava juice preparation site which was identified as the presumptive source of infection. The genotyping of all these isolates as TcId supports the view of a common source of infection in this oral Chagas disease outbreak through the ingestion of guava juice. Implications for clinical manifestations and dynamics of transmission cycles are discussed.
Assuntos
Doença de Chagas/epidemiologia , Doença de Chagas/parasitologia , Surtos de Doenças , Genes de Protozoários , Trypanosoma cruzi/genética , Animais , Sequência de Bases , Bebidas/parasitologia , Doença de Chagas/transmissão , Genótipo , Técnicas de Genotipagem , Humanos , Dados de Sequência Molecular , Psidium , Ratos/parasitologia , Instituições Acadêmicas , Alinhamento de Sequência , Trypanosoma cruzi/classificação , Trypanosoma cruzi/isolamento & purificação , Venezuela/epidemiologiaRESUMO
Dos ejemplares de Panstrongylus rufotuberculatus fueron capturados en una vivienda de El Hatillo, estado Miranda. En ambos se confirma la presencia de Trypanosoma cruzi. Se estudian algunos parámetros biológicos para estimar el comportamiento de uno de los aislados (Pr), encontrándose que tanto el cultivo en medios acelulares como la inoculación en ratones fueron exitosos. Así mismo, 73,3% de los Rhodnius de laboratorio se infectaron y 30,6% de los parásitos presentaron metaciclogénesis, mientras que in vitro se obtuvo 25,5%. La identificación molecular correspondió a T. cruzi. Este hallazgo es importante debido a la posible emergencia de esta especie silvestre que por alteración antrópica de sus hábitats naturales puede estar en proceso de dispersión, penetración y domiciliación de las viviendas, implicando la posibilidad de transmisión del parásito al ser humano y animales domésticos.
Two specimens of Panstrongylus rufotuberculatus were captured in a house in El Hatillo, Estado Miranda. In both specimens the presence of Trypanosoma cruzi was confirmed. We studied some biological parameters for estimating the behavior of the isolates, finding in both that cell-free culture media as inoculation in mice were successful. Also, 73.3% of Rhodnius prolixus fed on infected mice became infected and 30.6% of the parasites developed to metacyclic forms whereas in vitro only 25.5% was obtained. Furthermore, the molecular identification corresponded to T. cruzi. This finding is important due to the possible emergence of wild species by anthropogenic alteration of their natural habitats, and this may become a process of dispersion, penetration and clearance of houses, implying the possibility of transmitting the parasite to humans and pets.
Assuntos
Humanos , Masculino , Feminino , Doença de Chagas/transmissão , Panstrongylus/microbiologia , Parasitos/isolamento & purificação , Trypanosoma cruzi , Doenças Transmissíveis , Saúde PúblicaRESUMO
This study contains the first report of stridulatory sound observed in Panstrongylus rufotuberculatus Champion, 1899, and also a new record of this species in Venezuela. The conditions in which stridulation occurred are described, as well as the general environmental characteristics of the localities where it was found. This triatomine only performs the sound in conditions of extreme provocation.
Assuntos
Panstrongylus/fisiologia , Vocalização Animal/fisiologia , Animais , Masculino , Microscopia Eletrônica de Varredura , Panstrongylus/ultraestrutura , VenezuelaRESUMO
Este estudo contém o primeiro reporte da estridulação observada em Panstrongylus rufotuberculatus Champion, 1899, e um novo registro desta espécie na Venezuela. Descrevem-se as condições em que ocorre a estridulação, como também as características gerais das localidades onde foi capturado. Este triatomino só emite som em condições de extrema provocação.
Assuntos
Animais , Masculino , Panstrongylus/fisiologia , Vocalização Animal/fisiologia , Microscopia Eletrônica de Varredura , Panstrongylus/ultraestrutura , VenezuelaRESUMO
This study contains the first report of stridulatory sound observed in Panstrongylus rufotuberculatus Champion, 1899, and also a new record of this species in Venezuela. The conditions in which stridulation occurred are described, as well as the general environmental characteristics of the localities where it was found. This triatomine only performs the sound in conditions of extreme provocation.
Este estudo contém o primeiro reporte da estridulação observada em Panstrongylus rufotuberculatus Champion, 1899, e um novo registro desta espécie na Venezuela. Descrevem-se as condições em que ocorre a estridulação, como também as características gerais das localidades onde foi capturado. Este triatomino só emite som em condições de extrema provocação.
RESUMO
This study contains the first report of stridulatory sound observed in Panstrongylus rufotuberculatus Champion, 1899, and also a new record of this species in Venezuela. The conditions in which stridulation occurred are described, as well as the general environmental characteristics of the localities where it was found. This triatomine only performs the sound in conditions of extreme provocation.
Este estudo contém o primeiro reporte da estridulação observada em Panstrongylus rufotuberculatus Champion, 1899, e um novo registro desta espécie na Venezuela. Descrevem-se as condições em que ocorre a estridulação, como também as características gerais das localidades onde foi capturado. Este triatomino só emite som em condições de extrema provocação.
RESUMO
The high similarity between Trypanosoma cruzi and human ubiquitin prompted us to characterize the human humoral immunity to host and parasite ubiquitin in Chagas disease and its possible role in Chagas autoimmunity. We have used a simplified one step purification procedure to partially purify T. cruzi ubiquitin. Using this preparation we have performed ELISA and Western blots, to show that chagasic sera recognise T. cruzi but not human or Leishmania ubiquitin indicating a species-specific response. Our results show that despite the high degree of similarity in the primary structure of human and T. cruzi ubiquitins, the three amino acid difference is sufficient to distinguish parasite versus host proteins.
Assuntos
Doença de Chagas/imunologia , Trypanosoma cruzi/imunologia , Ubiquitinas/química , Ubiquitinas/imunologia , Sequência de Aminoácidos , Animais , Autoanticorpos/sangue , Autoimunidade , Western Blotting , Doença de Chagas/parasitologia , Ensaio de Imunoadsorção Enzimática , Humanos , Leishmania mexicana/imunologia , Leishmania mexicana/metabolismo , Dados de Sequência Molecular , Trypanosoma cruzi/química , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/metabolismo , Ubiquitinas/isolamento & purificaçãoRESUMO
Eleven antigenic clones were isolated from a Trypanosoma cruzi cDNA expression library using a pool of Chagasic sera from Venezuelan patients. These clones were tested with 26 Chagasic sera and 11 sera from patients with other diseases. One clone (Clone 2) reacted with the majority of the Chagasic sera and did not react with the non-Chagasic sera. Restriction enzyme digestion of Clone 2 DNA showed that it contained an insert of 5.2 kb. In a Southern blot of a pulse field gel electrophoresis, Clone 2 hybridized to three T. cruzi chromosomal fragments. By Northern blot analyses, it was observed that the clone hybridizes to a major T. cruzi RNA band of 0.97 kb and to two minor bands of 4.8 and 6.3 kb. The expression of these three RNAs was higher in trypomastigotes than in epimastigotes or spheromastigotes. Specific antibodies isolated against the beta-galactosidase-Clone 2 fusion protein expressed in E. coli reacted with a 28 kilodalton protein in T. cruzi.
Assuntos
Antígenos de Protozoários/isolamento & purificação , Proteínas de Protozoários/isolamento & purificação , Trypanosoma cruzi/imunologia , Animais , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Doença de Chagas/imunologia , Clonagem Molecular , DNA Complementar/genética , DNA de Protozoário/genética , Regulação da Expressão Gênica , Genes de Protozoários , Humanos , Peso Molecular , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Proteínas Recombinantes/imunologia , Sensibilidade e Especificidade , Trypanosoma cruzi/genéticaRESUMO
We demonstrate the presence of cyclic adenosine monophosphate (cAMP) in the fluid secreted by isolated Malpighian tubules of Rhodnius prolixus. In addition, we show that fifth-instar R. prolixus excrete cAMP in the urine after a meal of human blood. Nonstimulated isolated Malpighian tubules secrete small amounts of cAMP that increase about 10-fold after the addition of 5-hydroxytryptamine (5-HT). 5-HT is known to mimic R. prolixus diuretic hormone. The present findings demonstrate that 5-HT also acts via cAMP. The presence of cAMP in the rectal sac of the insect could be of importance in the differentiation of Trypanosoma cruzi and in the cycle of Chagas disease.
Assuntos
Cloaca/metabolismo , AMP Cíclico/metabolismo , Túbulos de Malpighi/metabolismo , Rhodnius/metabolismo , Triatominae/metabolismo , Animais , AMP Cíclico/urina , Humanos , Técnicas In Vitro , Serotonina/metabolismoRESUMO
We have studied the cell differentiation of Trypanosoma cruzi in an vitro system that allows the transformation of epimastigotes into metacyclic trypomastigotes. Intracellular cAMP levels of epimastigotes increased 3 fold prior to their differentiation into metacyclics where cAMP remained elevated 3.7 fold with respect to epimastigotes. We also observed a 3 fold increase in the specific activity of cAMP-binding of metacyclics crude homogenates. This activity resided in a cAMP-binding receptor protein (CARPT) which was different from the typical cAMP-binding subunits (RI and RII) of cAMP-dependent protein kinases, as shown by the use of polyclonal antibodies prepared against these two types of proteins. Anti-RI antibodies did not react with CARPT, and anti-RII antibodies gave a cross reaction with CARPT which was at least 1,000 fold less sensitive than the one shown by the homologous antigen. On Western blots CARPT displayed a major band with Mr = 87,000 instead of Mr = 56,000 for RII. These studies implicate that cAMP may act as a mediator of the cell differentiation of T. cruzi by a mechanism involving a novel type of cAMP-binding receptor.
Assuntos
Proteína Receptora de AMP Cíclico , AMP Cíclico/fisiologia , Transdução de Sinais , Trypanosoma cruzi/fisiologia , Animais , Proteínas de Transporte/fisiologia , Receptores de AMP Cíclico/fisiologiaRESUMO
The addition to epimastigotes cultures of T. cruzi, of either cAMP, monobutyryl-cAMP, dibutyryl-cAMP, 8-Br-cAMP (at 2 mM each), or the cAMP-phosphodiesterase inhibitor, papaverine (0.2 mM), promoted the in vitro differentiation of these parasite forms into metacyclics. This effect of cAMP may also be exerted in vivo in the insect vector, since cAMP was detected in the urine and in the Malpighi secretion fluids of Rodnius prolixus.