Résumé
Xanthomonas citri pv. citri (Xcc), the causal agent of Asiatic Citrus Canker, is an internationally major bacterial pathogen currently not reported from countries in the Mediterranean basin, including the EU. Some pathological diversity among strains was reported, leading to the description in Xcc of pathotypes differing in host range and aggressiveness. Xcc is recognized as a monomorphic pathogen and the very low intrapathovar diversity at housekeeping genes precludes the use of the increasingly popular MLST (MultiLocus Sequence Typing) for the global molecular surveillance of Xcc. We developed a new MLVA (MultiLocus Variable number of tandem repeats Analysis) scheme. It targeted 51 minisatellite loci dispersed over the Xcc genome with tandem repeat size ranging from 10 to 217-bp, thus allowing the use of standard agarose gel electrophoresis in laboratories that are not equipped with a genotyper. Among these loci, 34 were found to be polymorphic within a strain collection composed of strains from all continents where Xcc has been recorded, including recent outbreaks in Africa where the bacterium is reemerging. This typing scheme displayed a maximal typeability and repeatability. The produced data support the usefulness of this new MLVA scheme for global surveillance of Xcc. (Texte integral)