Reversible Changes in the Isoenzyme Electrophoretic Mobility Pattern and Infectivity in Clones of Trypanosoma cruzi

Alves, Ada M. B.; Tanuri, Amílcar; Almeida, Darcy Fontoura de; Krüger, Wanda M. A. von

doi:10.1006/expr.1993.1081

Cited by 21 publications

(24 citation statements)

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“…Isoenzyme and RAPD analyses showed a reversibility of the genetic profile of two T. cruzi isolates to the parental strain after 25 passages in mice. Alves et al (1993) have also observed reversible The biological diversity observed among the isolates could be attributed to the genetic potential of each vertebrate-host, in this case dogs and mice, in selecting parasite clones or subpopulations that are more adapted to the new environment. This phenomenon seems to be host-dependent, because although each dog had been inoculated with the same T. cruzi strain, they displayed different clinical forms of the disease.…”

Section: Discussionmentioning

confidence: 91%

Influence of the long-term Trypanosoma cruzi infection in vertebrate host on the genetic and biological diversity of the parasite

et al. 2005

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The influence of the long-term Trypanosoma cruzi infection in vertebrate host on the biological and genetic properties of the parasite was evaluated. Four T. cruzi isolates obtained from different chronic chagasic dogs infected with Berenice-78 T. cruzi strain during 2 and 7 years were comparatively analyzed. The long-term T. cruzi infection has led to alterations in parasitemia, virulence and pathogenicity of Be-78 strain for mice. These biological parameters varied from low to high in realation to the parental strain. Randomly amplified polymorphic DNA and isoenzyme profiles detected two distinct genetic groups of parasites. The first group included the parental strain and two T. cruzi isolates, and the second group the two other isolates. Interestingly, the isolates of the second group showed a reversibility of the genetic profile to the parental strain after 25 passages in mice. No correlation between the genetic groups and biological properties of the isolates was observed. Our findings confirmed the population heterogeneity of the Be-78 strain, and showed how differently it responds to the long-term infection in the same vertebrate hosts.

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Section: Discussionmentioning

confidence: 91%

Influence of the long-term Trypanosoma cruzi infection in vertebrate host on the genetic and biological diversity of the parasite

et al. 2005

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“…These microsatellite profile changes were unexpected because we used clonal T. cruzi stocks predicted to remain genetically stable (38), even considering the possibility of genetic exchange (24). However, genetic changes have already been observed in cultures of clonal protozoan parasites as a result of drug resistance selection or even spontaneously or by modification of the culture conditions used (1,2,27,30,31,45). Furthermore, we cannot exclude the possibility that these original stocks possessed different subpopulations present at levels too low for detection by conventional molecular techniques and/or that the passage of these stocks in laboratory animals or culture propitiated the preferential growth of such subpopulations.…”

Section: Discussionmentioning

confidence: 99%

Impact of Dual Infections on Chemotherapeutic Efficacy in BALB/c Mice Infected with Major Genotypes ofTrypanosoma cruzi

Martins

Silva

Valadares

et al. 2007

Antimicrob Agents Chemother

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The aim of this work was to investigate the impact of dual infections with stocks of Trypanosoma cruzi major genotypes on benznidazole (BZ) treatment efficacy. For this purpose, T. cruzi stocks representative of the genetic T. cruzi lineages, displaying different susceptibilities to BZ, belonging to the major T. cruzi genotypes broadly dispersed in North and South America and important in Chagas' disease epidemiology were used. Therapeutic efficacy was observed in 27.8% of the animals treated. Following BZ susceptibility classification, significant differences were observed in dual infections on the major genotype level, demonstrating that combinations of genotypes 19؉39 and genotypes 19؉32 led to a shift in the expected BZ susceptibility profile toward the resistance pattern. Analysis on the T. cruzi stock level demonstrated that 9 out of 24 dual infections shifted the expected BZ susceptibility profile compared with the respective single infections, including shifts toward lower and higher BZ susceptibilities. Microsatellite identification was able to identify a mixture of T. cruzi stocks in 7.7% of the T. cruzi isolates from infected and untreated mice (6.9%) and infected and treated but not cured mice (9.0%), revealing in some mixtures of BZ-susceptible and -resistant stocks that the T. cruzi stock identified after BZ treatment was previously susceptible in single infections. Considering the clonal structure and evolution of T. cruzi, an unexpected result was the identification of parasite subpopulations with distinct microsatellite alleles in relation to the original stocks observed in 12.2% of the isolates. Taken together, the data suggest that mixed infections, already verified in nature, may have an important impact on the efficacy of chemotherapy.

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“…Por otra parte, teniendo en cuenta los informes previos de estructura clonal del parásito, tanto para cepas oriundas de otros países de Latinoamérica (8,14) como para las de Colombia (26,27), las discrepancias entre los diferentes métodos de análisis empleados se pueden enmarcar dentro de una o varias de las siguientes situaciones: 1) los marcadores analizados poseen diferentes tasas de mutación entre ellos; por ejemplo, para el caso de las histonas, se conoce que estos genes son altamente conservados a lo largo de la escala filogenética (37), o 2) alguno de los marcadores puede estar sometido a presiones selectivas, como puede ser el caso de las isoenzimas (38). Sin embargo, tampoco se puede descartar la recombinación genética entre Dendograma basado en la distancia genética de Jaccard, obtenida según los perfiles de RAPD y agrupadas según el programa UPMGA/ NTSYS.…”

Section: Discussionunclassified

Estudio de la variabilidad de seis cepas colombianas de Trypanosoma cruzi mediante polimorfismos de longitud de fragmentos de restricción (RFLP) y amplificación aleatoria de ADN polimórfico (RAPD).

Rodríguez¹,

Escalante²,

Díez³

et al. 2002

biomedica

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La enfermedad de Chagas, causada por el hemoflagelado Trypanosoma cruzi, constituye un problema de salud pública en Colombia en donde diferentes informes indican la presencia de heterogeneidad entre poblaciones del parásito. En este estudio se analizaron seis cepas colombianas de T. cruzi, procedentes de distintas regiones geográficas del país, huéspedes y ciclos de transmisión, mediante las técnicas de amplificación aleatoria de ADN polimórfico (Random Amplified Polymorphic DNA, RAPD), isoenzimas y polimorfismo de longitud de fragmentos de restricción (Restriction Fragment Length Polymorphisms, RFLP), usando como sonda el gen de 1,2 kb que codifica para la histona H2A del parásito. Se encontró que las distancias genéticas entre los aislados varían considerablemente, ubicándose en el rango de 0,61 a 0,99, para el caso de los perfiles de RAPD (cebadores M13F y M13R), de 0 a 0,81, para el caso de los perfiles de RFLP (5 endonucleasas) y de 0,10 a 0,55, para el caso de las isoenzimas (13 sistemas enzimáticos). El elevado grado de variabilidad exhibido por los aislados colombianos del parásito podría estar implicado en el amplio espectro clínico de presentación de la enfermedad de Chagas en Colombia.Palabras clave: Trypanosoma cruzi, RAPD, RFLP, histona H2A, isoenzimas, polimorfismo. Genetic variability in six Colombian Trypanosoma cruzi strains detected by restriction fragment length polymorphisms (RFLP) and random amplified polymorphic DNA (RAPD)Chagas disease, caused by the hemoflagellate Trypanosoma cruzi, is a public health problem in Colombia. Previous reports have indicated the presence of heterogeneity among parasite populations. Six Colombian T. cruzi strains were obtained that differed by host, geographical region and transmission cycle. The genetic variability of each was compared by random amplified polymorphic DNA (RAPD), and isoenzymes. A restriction fragment length polymorphism (RFLP) was extracted using the 1.2 kb unit encoding the parasite's H2A histone as a probe. Genetic distances between the isolates varied greatly, from 0.611 to 0.99 as determined by RAPD profiles (M13F and M13R primers), between 0 and 0.81 by RFLP profiles ( 5 endonucleases), and between 0.10 and 0.55 by isoenzymes (13 enzymatic systems). Genetic distance matrixes derived from each of the three methods showed that Colombian strains exhibit a high degree of genetic differentiation. This may account for the broad clinical spectrum of Chagas disease in Colombia.

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Reversible Changes in the Isoenzyme Electrophoretic Mobility Pattern and Infectivity in Clones of Trypanosoma cruzi

Cited by 21 publications

References 0 publications

Influence of the long-term Trypanosoma cruzi infection in vertebrate host on the genetic and biological diversity of the parasite

Influence of the long-term Trypanosoma cruzi infection in vertebrate host on the genetic and biological diversity of the parasite

Impact of Dual Infections on Chemotherapeutic Efficacy in BALB/c Mice Infected with Major Genotypes ofTrypanosoma cruzi

Estudio de la variabilidad de seis cepas colombianas de Trypanosoma cruzi mediante polimorfismos de longitud de fragmentos de restricción (RFLP) y amplificación aleatoria de ADN polimórfico (RAPD).

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