Phylogenetic tree of MST genotypes of Rickettsia conorii isolates from humans and ticks, in Tunisia. The tree was constructed using the Neighbor joining method based on 3 concatenated intergenic spacer sequences in 34 MST genotypes. Bootstrap values (100 replicates), shown in MEGA5.2 software, were used for phylogenetic analysis. Filled triangles indicate R. conorii strains detected in the skin biopsies of Tunisian patients in this study. Filled circles indicate R. conorii strains detected in ticks.