Identification of Trypanosoma cruzi Genotypes Circulating in Chilean Chagasic Patients

Solari, Aldo; Campillay, R.; Ortíz, Sylvia; Wallace, Anne M.

doi:10.1006/expr.2001.4607

Cited by 51 publications

(54 citation statements)

References 24 publications

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“…The current sampling extends epidemiological findings obtained by several groups of Latin America, 8,22,[30][31][32] and particularly of Argentina, 21,[33][34][35][36] showing the predominance of TcIId infection in human and mammalian hosts.…”

Section: Introductionsupporting

confidence: 84%

Genotyping of Trypanosoma cruzi Sublineage in Human Samples from a North-East Argentina Area by Hybridization with DNA Probes and Specific Polymerase Chain Reaction (PCR)

Diez¹,

Lorenz²,

Ortíz³

et al. 2010

The American Society of Tropical Medicine and Hygiene

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Abstract. We have evaluated blood samples of chronic and congenital Trypanosoma cruzi -infected patients from the city of Reconquista located in the northeast of Argentina where no information was previously obtained about the genotype of infecting parasites. Fourteen samples of congenital and 19 chronical patients were analyzed by hybridization with DNA probes of minicircle hypervariable regions (mHVR). In congenital patients, 50% had single infections with TcIId, 7% single infections with TcIIe, 29% mixed infections with TcIId/e, and 7% had mixed infections with TcIId/b and 7% TcIId/b, respectively. In Chronical patients, 52% had single infections with TcIId, 11% single infections with TcIIe, 26% had mixed infections with TcIId/e, and 11% had non-identified genotypes. With these samples, we evaluated the minicircle lineage-specific polymerase chain reaction assay (MLS-PCR), which involves a nested PCR to HVR minicircle sequences and we found a correlation with hybridization probes of 96.4% for TcIId and 54.8% for TcIIe.

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Section: Introductionsupporting

confidence: 84%

Genotyping of Trypanosoma cruzi Sublineage in Human Samples from a North-East Argentina Area by Hybridization with DNA Probes and Specific Polymerase Chain Reaction (PCR)

Diez¹,

Lorenz²,

Ortíz³

et al. 2010

The American Society of Tropical Medicine and Hygiene

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“…Our group verified that in mixed infections, interactions between populations of T. cruzi may occur, resulting in important changes in the biological characteristics of the parasite and the evolution of the infection (12,25,32). Moreover, the importance of mixed infections in the epidemiology of Chagas' disease (8,35) and the evidence that they may result in significant alterations in the host-parasite relationship motivated the studies on the efficacy of chemotherapy in dual infections. Therefore, the goal of the present investigation was to evaluate in BALB/c mice the impact of dual T. cruzi infections on chemotherapy effectiveness, compared with the respective single infections with stocks from distinct major T. cruzi genotypes.…”

Section: Discussionsupporting

confidence: 58%

“…The existence of mixed infections in vertebrate and invertebrate hosts has been verified (8,35) and raises questions about their relevance to the epidemiology of Chagas' disease. At least in experimental mixed infections, important interactions between subpopulations of the mixtures resulted in changes in parasite biological properties (12,13,25,32).…”

mentioning

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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“…The membranes were prehybridized for at least 2 hours at 55°C and hybridized with total T. cruzi kinetoplast P 32 -labeled DNA (1 × 10 6 cpm/ membrane). 29 After hybridization, each membrane was washed three times for 30 minutes with 2× SSC (0.3 M NaCl, 0.03 M sodium citrate), 0.1% sodium dodecyl sulfate at 55°C, and analyzed with the Molecular Imager FX (Bio-Rad Laboratories, Hercules, CA). For genotyping, different T. cruzi clones were used as probes to determine the parasite lineage infecting each animal (TCI, clonet 20 sp.104 cl1; TCIIb, clonet 33 CBB cl3; TCIId, clonet 39, NR cl3; and TCIIe, clonet 43 v195 cl1).…”

Section: Methodsmentioning

confidence: 99%

“…This method has been validated by hybridization with probes constructed by PCR amplification of T. cruzi DNA of other specific genotypes. [29][30][31] Hybridizations with genotype-specific T. cruzi probes were repeated twice, and genotyping was conducted with samples that showed a DNA fragment.…”

Section: Methodsmentioning

confidence: 99%

Coexistence of Trypanosoma cruzi Genotypes in Wild and Periodomestic Mammals in Chile

et al. 2007

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Abstract. Epidemiologic evidence suggests a preferential association of Trypanosoma cruzi genotypes TCI and TCII with marsupials and placental mammals, respectively. We identify T. cruzi genotypes from 117 infected mammals. Minicircle DNA amplified by polymerase chain reaction and hybridization with a panel of four specific probes showed frequencies for the T. cruzi genotypes TCI, TCIIb, TCIId, and TCIIe of 38%, 41%, 26%, and 9%, respectively, in wild mammals. In peridomestic mammals, frequencies for the same clones were 29%, 33%, 43%, and 14%, respectively. As a whole, mixed infections are found in more than 31% of the cases, which indicates the coexistence of multiclonal strains circulating in nature, and the absence of specific associations between T. cruzi genotypes and reservoir hosts, including marsupials. The direct characterization of parasite genotypes emphasizes the importance of obtaining unbiased epidemiologic information from parasite-endemic areas. Results are discussed in the context of competition or facilitation of T. cruzi genotypes within hosts.

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Identification of Trypanosoma cruzi Genotypes Circulating in Chilean Chagasic Patients

Cited by 51 publications

References 24 publications

Genotyping of Trypanosoma cruzi Sublineage in Human Samples from a North-East Argentina Area by Hybridization with DNA Probes and Specific Polymerase Chain Reaction (PCR)

Genotyping of Trypanosoma cruzi Sublineage in Human Samples from a North-East Argentina Area by Hybridization with DNA Probes and Specific Polymerase Chain Reaction (PCR)

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

Coexistence of Trypanosoma cruzi Genotypes in Wild and Periodomestic Mammals in Chile

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