Dataset Information

Evolution and diversity of clonal bacteria: the paradigm of Mycobacterium tuberculosis.

ABSTRACT:

Background

Mycobacterium tuberculosis complex species display relatively static genomes and 99.9% nucleotide sequence identity. Studying the evolutionary history of such monomorphic bacteria is a difficult and challenging task.

Principal findings

We found that single-nucleotide polymorphism (SNP) analysis of DNA repair, recombination and replication (3R) genes in a comprehensive selection of M. tuberculosis complex strains from across the world, yielded surprisingly high levels of polymorphisms as compared to house-keeping genes, making it possible to distinguish between 80% of clinical isolates analyzed in this study. Bioinformatics analysis suggests that a large number of these polymorphisms are potentially deleterious. Site frequency spectrum comparison of synonymous and non-synonymous variants and Ka/Ks ratio analysis suggest a general negative/purifying selection acting on these sets of genes that may lead to suboptimal 3R system activity. In turn, the relaxed fidelity of 3R genes may allow the occurrence of adaptive variants, some of which will survive. Furthermore, 3R-based phylogenetic trees are a new tool for distinguishing between M. tuberculosis complex strains.

Conclusions/significance

This situation, and the consequent lack of fidelity in genome maintenance, may serve as a starting point for the evolution of antibiotic resistance, fitness for survival and pathogenicity, possibly conferring a selective advantage in certain stressful situations. These findings suggest that 3R genes may play an important role in the evolution of highly clonal bacteria, such as M. tuberculosis. They also facilitate further epidemiological studies of these bacteria, through the development of high-resolution tools. With many more microbial genomes being sequenced, our results open the door to 3R gene-based studies of adaptation and evolution of other, highly clonal bacteria.

SUBMITTER: Dos Vultos T

PROVIDER: S-EPMC2211405 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature

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Publications

Evolution and diversity of clonal bacteria: the paradigm of Mycobacterium tuberculosis.

Dos Vultos Tiago T Mestre Olga O Rauzier Jean J Golec Marcin M Rastogi Nalin N Rasolofo Voahangy V Tonjum Tone T Sola Christophe C Matic Ivan I Gicquel Brigitte B

PloS one 20080206 2

<h4>Background</h4>Mycobacterium tuberculosis complex species display relatively static genomes and 99.9% nucleotide sequence identity. Studying the evolutionary history of such monomorphic bacteria is a difficult and challenging task.<h4>Principal findings</h4>We found that single-nucleotide polymorphism (SNP) analysis of DNA repair, recombination and replication (3R) genes in a comprehensive selection of M. tuberculosis complex strains from across the world, yielded surprisingly high levels of ...[more]

PMID: 18253486

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Dataset Information

Evolution and diversity of clonal bacteria: the paradigm of Mycobacterium tuberculosis.

Background

Principal findings

Conclusions/significance

Publications

Evolution and diversity of clonal bacteria: the paradigm of Mycobacterium tuberculosis.

Similar Datasets

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