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Michel Tibayrenc - One of the best experts on this subject based on the ideXlab platform.

  • Multilocus Enzyme Electrophoresis for Parasites and Other Pathogens
    Methods of Molecular Biology, 2009
    Co-Authors: Michel Tibayrenc
    Abstract:

    In this chapter, I expose the main properties and theoretical background of a somewhat out-of-fashion technique, Multilocus Enzyme Electrophoresis (MLEE). I show that the remarkable properties of this marker-clear Mendelian inheritance, codominance, strong phylogenetic signal-are still valid, although of course more modern markers now are able to yield far more refined results. MLEE can still be used in many circumstances when a cheap and reliable marker is required. I summarize what have been the main contributions of MLEE to the study of parasites and other pathogens.

  • corrigendum to phylogenetic diversity of bat trypanosomes of subgenus schizotrypanum based on Multilocus Enzyme Electrophoresis random amplified polymorphic dna and cytrochrome b nucleotide sequence analyses inf gen evol 2 2003 201 208
    Infection Genetics and Evolution, 2003
    Co-Authors: Christian Barnabé, Sylvain Brisse, Michel Tibayrenc
    Abstract:

    Corrigendum to “Phylogenetic diversity of bat trypanosomes of subgenus Schizotrypanum based on Multilocus Enzyme Electrophoresis, random amplified polymorphic DNA, and cytrochrome b nucleotide sequence analyses” [Inf. Gen. Evol. 2 (2003) 201–208] C. Barnabe a,∗, S. Brisse b, M. Tibayrenc a a Genetique des Maladies Infectieuses, Unite Mixte de Recherche Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Developpement (IRD) n 9926 IRD BP 64501, 34394 Montpellier Cedex 05, France b Eijkman-Winkler Center for Microbiology, University Medical Center Utrecht, AZU G04.614, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands

  • Corrigendum to “Phylogenetic diversity of bat trypanosomes of subgenus Schizotrypanum based on Multilocus Enzyme Electrophoresis, random amplified polymorphic DNA, and cytrochrome b nucleotide sequence analyses” [Inf. Gen. Evol. 2 (2003) 201–208]
    Infection Genetics and Evolution, 2003
    Co-Authors: Christian Barnabé, Sylvain Brisse, Michel Tibayrenc
    Abstract:

    Corrigendum to “Phylogenetic diversity of bat trypanosomes of subgenus Schizotrypanum based on Multilocus Enzyme Electrophoresis, random amplified polymorphic DNA, and cytrochrome b nucleotide sequence analyses” [Inf. Gen. Evol. 2 (2003) 201–208] C. Barnabe a,∗, S. Brisse b, M. Tibayrenc a a Genetique des Maladies Infectieuses, Unite Mixte de Recherche Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Developpement (IRD) n 9926 IRD BP 64501, 34394 Montpellier Cedex 05, France b Eijkman-Winkler Center for Microbiology, University Medical Center Utrecht, AZU G04.614, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands

  • population structure and genetic typing of trypanosoma cruzi the agent of chagas disease a Multilocus Enzyme Electrophoresis approach
    Parasitology, 2000
    Co-Authors: Christian Barnabé, Sylvain Brisse, Michel Tibayrenc
    Abstract:

    A set of 434 Trypanosoma cruzi stocks from a wide ecogeographical range was analysed by Multilocus Enzyme Electrophoresis for 22 genetic loci. Strong linkage disequilibrium, not associated with geographical distance, and 2 main genetic clusters each considerably heterogeneous, was observed. These results support the hypotheses previously proposed that T. cruzi natural populations are composed of highly diversified genetic clones distributed into 2 main phylogenetic lineages: lineage 1, the most ubiquitous in the endemic area, was more frequently observed in sylvatic cycles, whereas lineage 2, predominant in humans and domestic cycles, in the southern part of the area surveyed, was further partitioned into 5 lesser genetic subdivisions. T. cruzi appears therefore subdivided into at least 6 discrete typing units' or DTUs (Tibayrenc, 1998a-c). We have identified various specific isoEnzyme markers (tags'; Tibayrenc, op. fit.) suitable for the routine identification of these DTUs for epidemiological tracking purposes. We discuss the correspondence with previous classifications and with the recent recommendations of the 90th anniversary of the discovery of Chagas disease symposium, as well as the impact of T. cruzi genetic variability on this parasite's hiomedical diversity.

  • identification of six trypanosoma cruzi phylogenetic lineages by random amplified polymorphic dna and Multilocus Enzyme Electrophoresis
    International Journal for Parasitology, 2000
    Co-Authors: Sylvain Brisse, Christian Barnabé, Michel Tibayrenc
    Abstract:

    Abstract Genetic characterisation of Trypanosoma cruzi variants is of foremost importance, due to considerable genetic and biological heterogeneity in the parasite populations. Two major phylogenetic lineages, each highly heterogeneous, have been previously described within this species. Here we characterised a geographically and ecologically diverse sample of stocks representative of the breadth of the known clonal diversity of each major lineage, using random amplified polymorphic DNA with 20 primers and Multilocus Enzyme Electrophoresis at 22 loci. Molecular hybridisation experiments were performed to control the homology of randomly amplified DNA markers. Both sets of data were highly consistent and supported the existence of two major lineages. Additionally, we found that lineage 2 appeared further partitioned into five sharply delineated phylogenetic clusters, each comprising one of the following reference strains: CanIII cl1 (Z3 reference), M5631 cl5, Esmeraldo cl3 (Z2 reference), CL Brener, and MN cl2. The two first clusters were found mainly in sylvatic environments, whereas the three latter were restricted to domestic transmission cycles and were only collected South to the Amazon Basin. In contrast, lineage 1, which included Miles' Z1 reference strain X10 cl1, was not further subdivided and was encountered across the entire endemic area, in both domestic and sylvatic cycles. Thus, T. cruzi appeared to be subdivided into six discrete typing units, or DTUs, exhibiting distinct geographic and ecological ranges. Reliable diagnostic markers for the two major lineages and the five smaller DTUs of lineage 2 are described, and correspondence with previous classifications of T. cruzi genotypes is given in order to help communication on T. cruzi phylogenetic diversity.

José Francisco Höfling - One of the best experts on this subject based on the ideXlab platform.

  • Clonal characterization of Streptococcus mutans strains by Multilocus Enzyme Electrophoresis
    Brazilian Journal of Microbiology, 2006
    Co-Authors: Rosimeire Takaki Rosa, José Francisco Höfling, Reginaldo Bruno Gonçalves, Marcelo Henrique Napimoga, Edvaldo Antonio Ribeiro Rosa
    Abstract:

    Twenty-one Streptococcus mutans strains were clustered by Multilocus Enzyme Electrophoresis (MLEE). Six isoEnzymes showed strong infra-specific discriminatory power (M1P, MPI, PLP, NSP, GOT, and LAP). MLEE is a robust technique that may be used to explore clonal diversity of S. mutans isolates in epidemiological surveys.

  • TYPING STREPTOCOCCUS MUTANS BY Multilocus Enzyme Electrophoresis
    2005
    Co-Authors: Rosimeire Takaki Rosa, José Francisco Höfling, Reginaldo Bruno Gonçalves, Marcelo Henrique Napimoga, Edvaldo Antonio Ribeiro Rosa
    Abstract:

    OBJECTIVES: It was evaluated the use of Multilocus Enzyme Electrophoresis (MLEE) for the characterization of Streptococcus mutans. MATERIAL AND METHODS: Five strains of such microrganisms were grown in liquid culture medium and their cytoplasm proteins were extracted. After gel electrophoreses, the catalytic activity was explored for 23 isoEnzymes. RESULTS: Six Enzymes (mannitol-1-phosphate dehydrogenase, mannose-phosphate isomerase, nucleoside phosphorylase, phenylalanyl-leucine peptidase, leucine aminopeptidase, and glutamic-oxalacetic transaminase) furnished bands that allowed the strains characterization at intra-specific level. CONCLUSION: MLEE is a robust technique that may be used to explore diversity among clinical isolates of cariogenic S. mutans in epidemiological surveys.

  • Multilocus Enzyme Electrophoresis typing of Candida albicans populations isolated from healthy children according to socioeconomic background
    Revista Brasileira De Epidemiologia, 2005
    Co-Authors: Marcelo Fabiano Gomes Boriollo, Wagner Luis De Carvalho Bernardo, Edvaldo Antonio Ribeiro Rosa, Reginaldo Bruno Gonçalves, Denise Madalena Palomari Spolidorio, José Francisco Höfling
    Abstract:

    The aim of this research was to evaluate the genetic diversity within and between C. albicans populations isolated from the oral cavity of healthy Brazilian children classified into five socioeconomic categories (A to E). Multilocus Enzyme Electrophoresis (MLEE) analysis was the method used to assess genetic diversity. High genetic diversity was observed in all populations that showed predominance of some C. albicans subtypes (Electrophoretic Types - ETs). However, no correlation was observed between a specific ET and a specific population of children. Clustering analysis showed one or more highly related ET clusters, suggesting the existence of indirect and direct propagation routes of C. albicans among healthy children. Microevolutionary changes were observed in some C. albicans populations isolated from children with the same or very similar socioeconomic condition. Furthermore, low transition of C. albicans subtypes can be occurring among certain populations of children coming from high and medium/high, or high and medium/low, or medium/high and medium/low socioeconomic categories, which can also be explained by their own socioeconomic and cultural characteristics.

  • Oral Candida albicans and Candida dubliniensis differentiation by Multilocus Enzyme Electrophoresis and sodium dodecylsulphate-polyacrylamide gel Electrophoresis
    Revista Argentina de microbiologia, 2003
    Co-Authors: Edvaldo Antonio Ribeiro Rosa, Rosimeire Takaki Rosa, Wagner Luis De Carvalho Bernardo, Marcelo Fabiano Gomes Boriollo, José Francisco Höfling
    Abstract:

    Five oral strains of Candida albicans and five C. dubliniensis, as well as their respective type-strains, were analyzed by Multilocus Enzyme Electrophoresis (MLEE) and sodium dodecyl-sulfate polyacrylamide gel Electrophoresis (SDS-PAGE). After electrophoreses and numerical analyses, we obtained two distinct species-specific taxa, which may justify the use of MLEE and SDS-PAGE as reliable methods for differentiation and complementary identification of C. dubliniensis.

  • Grouping oral Candida species by Multilocus Enzyme Electrophoresis.
    International Journal of Systematic and Evolutionary Microbiology, 2000
    Co-Authors: Edvaldo Antonio Ribeiro Rosa, Rosimeire Takaki Rosa, Cássio Vicente Pereira, José Francisco Höfling
    Abstract:

    Multilocus Enzyme Electrophoresis (MLEE) and numerical taxonomic methods were used to establish the degrees of relatedness among five Candida species commonly isolated from humans oral cavities. Of twenty enzymic systems assayed, five showed no enzymic activity (aspartate dehydrogenase, mannitol dehydrogenase, sorbitol dehydrogenase, glucosyl transferase and alpha-amylase). The obtained data revealed that some of these Enzymes are capable of distinguishing strains of different species, but most of them could not organize all strains in their respective species-specific clusters. Numerical classification based on MLEE polymorphism must be regarded for surveys involving just one Candida species.

Edvaldo Antonio Ribeiro Rosa - One of the best experts on this subject based on the ideXlab platform.

  • Clonal characterization of Streptococcus mutans strains by Multilocus Enzyme Electrophoresis
    Brazilian Journal of Microbiology, 2006
    Co-Authors: Rosimeire Takaki Rosa, José Francisco Höfling, Reginaldo Bruno Gonçalves, Marcelo Henrique Napimoga, Edvaldo Antonio Ribeiro Rosa
    Abstract:

    Twenty-one Streptococcus mutans strains were clustered by Multilocus Enzyme Electrophoresis (MLEE). Six isoEnzymes showed strong infra-specific discriminatory power (M1P, MPI, PLP, NSP, GOT, and LAP). MLEE is a robust technique that may be used to explore clonal diversity of S. mutans isolates in epidemiological surveys.

  • TYPING STREPTOCOCCUS MUTANS BY Multilocus Enzyme Electrophoresis
    2005
    Co-Authors: Rosimeire Takaki Rosa, José Francisco Höfling, Reginaldo Bruno Gonçalves, Marcelo Henrique Napimoga, Edvaldo Antonio Ribeiro Rosa
    Abstract:

    OBJECTIVES: It was evaluated the use of Multilocus Enzyme Electrophoresis (MLEE) for the characterization of Streptococcus mutans. MATERIAL AND METHODS: Five strains of such microrganisms were grown in liquid culture medium and their cytoplasm proteins were extracted. After gel electrophoreses, the catalytic activity was explored for 23 isoEnzymes. RESULTS: Six Enzymes (mannitol-1-phosphate dehydrogenase, mannose-phosphate isomerase, nucleoside phosphorylase, phenylalanyl-leucine peptidase, leucine aminopeptidase, and glutamic-oxalacetic transaminase) furnished bands that allowed the strains characterization at intra-specific level. CONCLUSION: MLEE is a robust technique that may be used to explore diversity among clinical isolates of cariogenic S. mutans in epidemiological surveys.

  • Multilocus Enzyme Electrophoresis typing of Candida albicans populations isolated from healthy children according to socioeconomic background
    Revista Brasileira De Epidemiologia, 2005
    Co-Authors: Marcelo Fabiano Gomes Boriollo, Wagner Luis De Carvalho Bernardo, Edvaldo Antonio Ribeiro Rosa, Reginaldo Bruno Gonçalves, Denise Madalena Palomari Spolidorio, José Francisco Höfling
    Abstract:

    The aim of this research was to evaluate the genetic diversity within and between C. albicans populations isolated from the oral cavity of healthy Brazilian children classified into five socioeconomic categories (A to E). Multilocus Enzyme Electrophoresis (MLEE) analysis was the method used to assess genetic diversity. High genetic diversity was observed in all populations that showed predominance of some C. albicans subtypes (Electrophoretic Types - ETs). However, no correlation was observed between a specific ET and a specific population of children. Clustering analysis showed one or more highly related ET clusters, suggesting the existence of indirect and direct propagation routes of C. albicans among healthy children. Microevolutionary changes were observed in some C. albicans populations isolated from children with the same or very similar socioeconomic condition. Furthermore, low transition of C. albicans subtypes can be occurring among certain populations of children coming from high and medium/high, or high and medium/low, or medium/high and medium/low socioeconomic categories, which can also be explained by their own socioeconomic and cultural characteristics.

  • Oral Candida albicans and Candida dubliniensis differentiation by Multilocus Enzyme Electrophoresis and sodium dodecylsulphate-polyacrylamide gel Electrophoresis
    Revista Argentina de microbiologia, 2003
    Co-Authors: Edvaldo Antonio Ribeiro Rosa, Rosimeire Takaki Rosa, Wagner Luis De Carvalho Bernardo, Marcelo Fabiano Gomes Boriollo, José Francisco Höfling
    Abstract:

    Five oral strains of Candida albicans and five C. dubliniensis, as well as their respective type-strains, were analyzed by Multilocus Enzyme Electrophoresis (MLEE) and sodium dodecyl-sulfate polyacrylamide gel Electrophoresis (SDS-PAGE). After electrophoreses and numerical analyses, we obtained two distinct species-specific taxa, which may justify the use of MLEE and SDS-PAGE as reliable methods for differentiation and complementary identification of C. dubliniensis.

  • Grouping oral Candida species by Multilocus Enzyme Electrophoresis.
    International Journal of Systematic and Evolutionary Microbiology, 2000
    Co-Authors: Edvaldo Antonio Ribeiro Rosa, Rosimeire Takaki Rosa, Cássio Vicente Pereira, José Francisco Höfling
    Abstract:

    Multilocus Enzyme Electrophoresis (MLEE) and numerical taxonomic methods were used to establish the degrees of relatedness among five Candida species commonly isolated from humans oral cavities. Of twenty enzymic systems assayed, five showed no enzymic activity (aspartate dehydrogenase, mannitol dehydrogenase, sorbitol dehydrogenase, glucosyl transferase and alpha-amylase). The obtained data revealed that some of these Enzymes are capable of distinguishing strains of different species, but most of them could not organize all strains in their respective species-specific clusters. Numerical classification based on MLEE polymorphism must be regarded for surveys involving just one Candida species.

Patrick Boerlin - One of the best experts on this subject based on the ideXlab platform.

  • Genetic structure of the genus Leptospira by Multilocus Enzyme Electrophoresis
    International Journal of Systematic and Evolutionary Microbiology, 1999
    Co-Authors: M Letocart, F Boerlin-petzold, Jerome Goudet, Guy Baranton, Patrick Boerlin, Philippe Perolat
    Abstract:

    Thirty strains from the 11 species of the genus Leptospira were studied by Multilocus Enzyme Electrophoresis at 12 Enzyme loci, all of which were polymorphic. The mean number of alleles per locus was 6.5. Twenty-five electrophoretic types were distinguished. Grouping of the strains by cluster analysis was in general agreement with species delineation as determined by DNA-DNA hybridization, except for the strains of Leptospira meyeri and Leptospira inadai, which were scattered throughout the genus, reflecting previously recognized taxonomic uncertainties. Analysis of the clonality within Leptospira interrogans sensu stricto indicated that this population was relatively heterogeneous and a lack of gene linkage disequilibrium could not be excluded. There was a genetic discrimination between the pathogenic species and the saprophytic ones. The phenotypically intermediate species (L. inadai and Leptospira fainei) were also genetically separated and were probably closer to the saprophytes than to the pathogens.

  • Applications of Multilocus Enzyme Electrophoresis in medical microbiology
    Journal of Microbiological Methods, 1997
    Co-Authors: Patrick Boerlin
    Abstract:

    Abstract Multilocus Enzyme Electrophoresis has been used since the beginning of the eighties for the study of numerous microbial pathogens. The principles of this technique are presented and its application for the study of population genetics, of systematics, and of molecular epidemiology are discussed. Several examples from the work of the author and from other laboratories illustrate the usefulness of the method in these three fields of medical microbiology. Finally, Multilocus Enzyme Electrophoresis is compared with recent methods of molecular biology and the future of Multilocus Enzyme Electrophoresis is discussed.

  • Multilocus Enzyme Electrophoresis for characterization of Listeria monocytogenes isolates : results of an international comparative study
    International Journal of Food Microbiology, 1996
    Co-Authors: D A Caugant, Fraser E. Ashton, Joseph Harvey, William F. Bibb, Patrick Boerlin, William Donachie, A Gilmour, Birgit Nørrung
    Abstract:

    Abstract Multilocus Enzyme Electrophoresis (MEE) is a standard technique that is used to elucidate the epidemiology of a variety of bacterial species. Recently, the method has been employed by several laboratories for investigations of clinical and foodborne isolates of Listeria monocytogenes. To assess the sensitivity and reproducibility of MEE in characterising L. monocytogenes isolates for epidemiological purposes and, ultimately, to agree on a standard protocol, seven laboratories participated in a blinded study of 80 strains. The strain collection included both epidemiologically related and unrelated isolates. Each laboratory used its own protocol for MEE. The number of Enzymes that were assayed by the laboratories ranged from 8 to 23, and the total number of identified electrophoretic types (ETs) varied between 14 and 25. Of the 11 pairs of duplicate strains, the number of pairs recognised as identical by the seven laboratories ranged from 3 to 10 (median = 8). From 10 to 18 (median = 15) of the 22 groups of epidemiological related strains were recognised as homogeneous by the different laboratories. The discriminatory power of the method, calculated using Simpson's index of diversity for 69 strains (80 strains minus the 11 duplicates), ranged from 0.827 to 0.925. This relatively low discriminatory power is a consequence of a somewhat low genetic diversity of L. monocytogenes compared to other bacterial species. Efforts should be pursued to standardise the method in order to improve the intra-and inter-laboratory reproducibility.

  • typing candida albicans oral isolates from human immunodeficiency virus infected patients by Multilocus Enzyme Electrophoresis and dna fingerprinting
    Journal of Clinical Microbiology, 1996
    Co-Authors: Patrick Boerlin, F Boerlinpetzold, Christian Durussel, Jeanluc Pagani, Jerome Goudet, Jean Philippe Chave, Jacques Bille
    Abstract:

    A total of 189 Candida albicans isolates have been typed by Multilocus Enzyme Electrophoresis. The results obtained confirm the clonal mode of reproduction of C. albicans. The C. albicans populations found in the oropharynx of human immunodeficiency virus (HIV)-infected patients, in the oropharynx of healthy carriers, or in association with invasive candidiasis could not be distinguished. No clone or group of clones could be associated with the appearance of clinical disorders or with a reduced in vitro susceptibility to the antifungal agent fluconazole. Multiple and sequential oral isolates from 24 HIV-infected patients were also typed by restriction Enzyme analysis with the Enzymes EcoRI and HinfI and by use of the Ca3 repetitive probe. The results obtained by the combination of all three typing methods show that all but one patient each carried a unique major C. albicans clone in their oropharynx. The 21 patients with sequential isolates had the same C. albicans clones in their throats during recurrent oropharyngeal candidiasis episodes, independently of clinical status or of changes of in vitro susceptibility to fluconazole. Finally, several isolates of the same C. albicans clone found simultaneously in the oropharynx of a patient may present different levels of susceptibility to fluconazole.

  • Typing Candida albicans Oral Isolates from Human Immunodeficiency Virus-Infected Patients by Multilocus Enzyme Electrophoresis
    1995
    Co-Authors: Dna Fingerprinting, F Boerlin-petzold, Patrick Boerlin, Christian Durussel
    Abstract:

    A total of 189 Candida albicans isolates have been typed by Multilocus Enzyme Electrophoresis. The results obtained confirm the clonal mode of reproduction of C. albicans. The C. albicans populations found in the oro-pharynx of human immunodeficiency virus (HIV)-infected patients, in the oropharynx of healthy carriers, or in association with invasive candidiasis could not be distinguished. No clone or group of clones could be asso-ciated with the appearance of clinical disorders or with a reduced in vitro susceptibility to the antifungal agent fluconazole. Multiple and sequential oral isolates from 24 HIV-infected patients were also typed by restriction Enzyme analysis with the Enzymes EcoRI and HinfI and by use of the Ca3 repetitive probe. The results obtained by the combination of all three typing methods show that all but one patient each carried a unique major C. albicans clone in their oropharynx. The 21 patients with sequential isolates had the same C. albicans clones in their throats during recurrent oropharyngeal candidiasis episodes, independently of clinical status or of changes of in vitro susceptibility to fluconazole. Finally, several isolates of the same C. albicans clone found simultaneously in the oropharynx of a patient may present different levels of susceptibility to fluconazole. Among the numerous AIDS-associated diseases, oropharyn-geal candidiasis (OPC) is the most frequent, with up to 90 % of HIV-infected patients suffering from it at one time or anothe

Christian Barnabé - One of the best experts on this subject based on the ideXlab platform.

  • corrigendum to phylogenetic diversity of bat trypanosomes of subgenus schizotrypanum based on Multilocus Enzyme Electrophoresis random amplified polymorphic dna and cytrochrome b nucleotide sequence analyses inf gen evol 2 2003 201 208
    Infection Genetics and Evolution, 2003
    Co-Authors: Christian Barnabé, Sylvain Brisse, Michel Tibayrenc
    Abstract:

    Corrigendum to “Phylogenetic diversity of bat trypanosomes of subgenus Schizotrypanum based on Multilocus Enzyme Electrophoresis, random amplified polymorphic DNA, and cytrochrome b nucleotide sequence analyses” [Inf. Gen. Evol. 2 (2003) 201–208] C. Barnabe a,∗, S. Brisse b, M. Tibayrenc a a Genetique des Maladies Infectieuses, Unite Mixte de Recherche Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Developpement (IRD) n 9926 IRD BP 64501, 34394 Montpellier Cedex 05, France b Eijkman-Winkler Center for Microbiology, University Medical Center Utrecht, AZU G04.614, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands

  • Corrigendum to “Phylogenetic diversity of bat trypanosomes of subgenus Schizotrypanum based on Multilocus Enzyme Electrophoresis, random amplified polymorphic DNA, and cytrochrome b nucleotide sequence analyses” [Inf. Gen. Evol. 2 (2003) 201–208]
    Infection Genetics and Evolution, 2003
    Co-Authors: Christian Barnabé, Sylvain Brisse, Michel Tibayrenc
    Abstract:

    Corrigendum to “Phylogenetic diversity of bat trypanosomes of subgenus Schizotrypanum based on Multilocus Enzyme Electrophoresis, random amplified polymorphic DNA, and cytrochrome b nucleotide sequence analyses” [Inf. Gen. Evol. 2 (2003) 201–208] C. Barnabe a,∗, S. Brisse b, M. Tibayrenc a a Genetique des Maladies Infectieuses, Unite Mixte de Recherche Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Developpement (IRD) n 9926 IRD BP 64501, 34394 Montpellier Cedex 05, France b Eijkman-Winkler Center for Microbiology, University Medical Center Utrecht, AZU G04.614, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands

  • population structure and genetic typing of trypanosoma cruzi the agent of chagas disease a Multilocus Enzyme Electrophoresis approach
    Parasitology, 2000
    Co-Authors: Christian Barnabé, Sylvain Brisse, Michel Tibayrenc
    Abstract:

    A set of 434 Trypanosoma cruzi stocks from a wide ecogeographical range was analysed by Multilocus Enzyme Electrophoresis for 22 genetic loci. Strong linkage disequilibrium, not associated with geographical distance, and 2 main genetic clusters each considerably heterogeneous, was observed. These results support the hypotheses previously proposed that T. cruzi natural populations are composed of highly diversified genetic clones distributed into 2 main phylogenetic lineages: lineage 1, the most ubiquitous in the endemic area, was more frequently observed in sylvatic cycles, whereas lineage 2, predominant in humans and domestic cycles, in the southern part of the area surveyed, was further partitioned into 5 lesser genetic subdivisions. T. cruzi appears therefore subdivided into at least 6 discrete typing units' or DTUs (Tibayrenc, 1998a-c). We have identified various specific isoEnzyme markers (tags'; Tibayrenc, op. fit.) suitable for the routine identification of these DTUs for epidemiological tracking purposes. We discuss the correspondence with previous classifications and with the recent recommendations of the 90th anniversary of the discovery of Chagas disease symposium, as well as the impact of T. cruzi genetic variability on this parasite's hiomedical diversity.

  • identification of six trypanosoma cruzi phylogenetic lineages by random amplified polymorphic dna and Multilocus Enzyme Electrophoresis
    International Journal for Parasitology, 2000
    Co-Authors: Sylvain Brisse, Christian Barnabé, Michel Tibayrenc
    Abstract:

    Abstract Genetic characterisation of Trypanosoma cruzi variants is of foremost importance, due to considerable genetic and biological heterogeneity in the parasite populations. Two major phylogenetic lineages, each highly heterogeneous, have been previously described within this species. Here we characterised a geographically and ecologically diverse sample of stocks representative of the breadth of the known clonal diversity of each major lineage, using random amplified polymorphic DNA with 20 primers and Multilocus Enzyme Electrophoresis at 22 loci. Molecular hybridisation experiments were performed to control the homology of randomly amplified DNA markers. Both sets of data were highly consistent and supported the existence of two major lineages. Additionally, we found that lineage 2 appeared further partitioned into five sharply delineated phylogenetic clusters, each comprising one of the following reference strains: CanIII cl1 (Z3 reference), M5631 cl5, Esmeraldo cl3 (Z2 reference), CL Brener, and MN cl2. The two first clusters were found mainly in sylvatic environments, whereas the three latter were restricted to domestic transmission cycles and were only collected South to the Amazon Basin. In contrast, lineage 1, which included Miles' Z1 reference strain X10 cl1, was not further subdivided and was encountered across the entire endemic area, in both domestic and sylvatic cycles. Thus, T. cruzi appeared to be subdivided into six discrete typing units, or DTUs, exhibiting distinct geographic and ecological ranges. Reliable diagnostic markers for the two major lineages and the five smaller DTUs of lineage 2 are described, and correspondence with previous classifications of T. cruzi genotypes is given in order to help communication on T. cruzi phylogenetic diversity.

  • genetic characterization of six parasitic protozoa parity between random primer dna typing and Multilocus Enzyme Electrophoresis
    Proceedings of the National Academy of Sciences of the United States of America, 1993
    Co-Authors: Michel Tibayrenc, Katja Neubauer, Francoise Guerrini, Christian Barnabé, Douglas Skarecky, Francisco J Ayala
    Abstract:

    We have assayed genetic polymorphisms in several species of parasitic protozoa by means of random amplified polymorphic DNA (RAPD). One goal was to ascertain the suitability of RAPD markers for investigating genetic and evolutionary problems, particularly in organisms, such as the parasitic protozoa, unsuitable for traditional methods of genetic analysis. Another goal was to test certain hypotheses concerning Trypanosoma cruzi, and other protozoa, that have been established by Multilocus Enzyme Electrophoresis. The RAPD results corroborate the hypothesis that the population structure of T. cruzi is clonal and yield a phylogeny of the clonal lineages in agreement with the one obtained by Enzyme Electrophoresis. This parity between the two sets of results confirms that RAPD markers are reliable genetic markers. The RAPD markers are also suitable for reconstructing species phylogenies and as diagnostic characters of species and subspecific lineages. The number of DNA polymorphisms that can be detected by the RAPD method seems virtually unlimited, since the number of primers can be increased effectively at will. The RAPD method is well suited for investigating genetic and evolutionary questions in certain organisms, because it is cost effective and demands no previous genetic knowledge about the organism.