Abstract
In this study, we attempt to highlight part of the adaptive and phylogenetic constraints in mycobacterialpathogenicity. For this purpose, we first provide a phylogeny ofMycobacteriabased on cladistic analyses of 64different taxa. We then performed a comparative analysis, taking into account both ecological factors andphylogenetic relationships. The GLIM modelling analysis showed that different ecological and phylogeneticfactors might be invoked to explain the variation in pathogenicity levels. Interestingly, the most harmful specieswere shown to be connected with the most diversified habitats. However, the independent contrast analysisrevealed that once phylogeny was taken into account, none of the relationships between ecological factors andpathogenicity remained significant, and the pathogenicity appeared to be phylogenetically inherited amongmycobacteria. The most pathogen were found in the slow-growing /long helix 18 group, and within this group inthe most derived taxa.