Tropheryma whipplei genome at the beginning of the post-genomic era

Tropheryma whipplei is a Gram positive human pathogen that is the causative agent of Whipple's disease. Nearly one century elapsed between the first description of the disease in 1907 and the cultivation of this bacterium within eukaryotic cell cultures in 2000. This achievement has made possible genome sequencing of this poorly studied microorganism. This review summarizes post-genomic knowledge resulting from these genomic data. To compare the theoretical genetic capabilities of T. whipplei with those of other sequenced bacteria, a virtual microarray representation was generated. This in silico analysis supports the concept of independent evolution pathways for microbial pathogens. Concrete post-genomic consequences related to clinical microbiology such as the analysis of antibiotic susceptibility or the design of molecular tools convenient for PCR detection and epidemiology studies are described. Analysis of whole-cell metabolic networks of T. whipplei also provide clues for designing axenic media for this pathogen that is particularly recalcitrant to cultivation. This opens the way to investigate transcriptome analysis of T. whipplei by microarrays. Future prospects are also discussed.