Many of the most important plant pathogens belong to the genus Xanthomonas. For this reason, five genomes belonging to three different species were already completely sequenced, two different isolates of Xanthomonas campestris pv. campestris (Xcc), Xanthomonas axonopodis pv. citri (Xac), Xanthomonas axonopodis pv. vesicatoria (Xav) and Xanthomonas oryzae pv. oryzae (Xoo). These genomes show some differences, mainly in relation to chromosomal rearrengements but variations in the sequences are also observed.
    In the present work, a shotgun genomic library was constructed for Xanthomonas campestris pv. viticola (Xcv). This bacterium causes the grape bacterial canker and is currently classified as a pathovar of Xanthomonas campestris even though it does not truly belong to this species since only pathovars with host range in the Brassicaceae and Plantaginaceae families should be considered Xanthomonas campestris sensu stricto. For being a pathogen of a plant belonging to the family Vitaceae, this bacterium was classified as Xanthomonas campestris sensu lato, until reallocated in a more appropriated species. After sequencing of 196 clones, the sequences were clusterized and generated close to 110 clusters. Their sequences were compared with the complete genomes of Xac, Xcc, Xav and Xoo using the Blastn tool. The resulting file was parsed with a perl script, which extracted the percentage of identity obtained in this analysis for each cluster and the four genomes. The average percentage of identity were 95.33, 88.95, 65.39 and 71.61 for Xac, Xav, Xcc, and Xoo, respectively. For this analysis it is clear that Xcv is not as close to Xcc as it is to Xac and therefore it should be reallocated in the Xanthomonas axonopodis species instead of Xanthomonas campestris. Interestingly, Xac and Xav may have come from the same geographic region and by the high similarity observed for the sequences from these two bacteria, they may also share the same ancestor.