IS6110 element distribution in Tunisian clinical strains and phylogenetic relationship generated by its mobility

The dynamics of IS6110 transposition is a valuable epidemiological tool in tuberculosis studies. In the present work, we studied IS6110 distribution along the genome of 58 unrelated clones and go over phylogenetic relationship between them by performing a molecular study with GL-PCR methodology. A total number of 309 insertion sites have been detected showing that IS6110 integration in samples studied crossed randomly several positions through the Mycobacterium tuberculosis genome. These sites were divided into 232 sequences having homologous in reference strains mainly in M. tuberculosis H37Rv strain and 77 other unique regions that did not have counterparts in reference strains fully sequenced and available in global databases. Most insertions occurred in coding regions. 114 insertions took place in the direction of the replication fork and 118 insertions were oriented against the direction of the replication fork, carried by the complementary strand of the chromosome. No clustered patterns have been illustrated. Several genetic statistical tests have been performed with language R package software to study the distribution and the symmetry of IS6110 insertion events. Our data confirm that IS6110 element prevalence and effect on genome function demonstrate the potential of this transposon as an evolutionary marker and as the best indicator of essential/virulence genes. In fact, survey of patterns of IS6110 insertions in circulating isolates may provide useful information for populational studies mainly in epidemic situations

کلیدواژه ها:

Mycobacterium tuberculosis ، IS6110 element ، Clinical strains ، Phylogeny ،