Characterization of curtobacterium flaccumfaciens pathovars by AFLP, rep-PCR and pulsed-field gel electrophoresis.

The bacterial species Curtobacterium flaccumfaciens encompasses a group of closely related phytopathogens subdivided into pathovars that exhibit differences in host range. To date, reliable differentiation of pathovars and identification of unknown isolates to the pathovar-level can only be achieved on the basis of host testing. In this study, representative strains from C. flaccumfaciens pathovars and related species were examined using a range of genomic fingerprinting techniques to ascertain their application as additional or potential alternatives to host testing. Amplified fragment length polymorphism (AFLP) and repetitive sequence polymerase chain reaction (rep-PCR) analyses enabled the categorisation of some, but not all strains, in their respective pathovars. In contrast, all strains were correctly assigned to pathovars using HindIII and XbaI macro-restriction digests in conjunction with pulsed-field gel electrophoresis (PFGE). Fingerprints generated by PFGE not only supported the current pathovar rankings within C. flaccumfaciens, they also identified subgroups within pathovars flaccumfaciens, oortii and poinsettiae.