Neighbor-joining trees based on MLST data and RFLP data for putative virulence determinants (experiment 1). Panel A, MLST; panel B, virulence gene RFLP. The MLST tree also includes MLST sequences for reference strains of major clonal complexes established by Wareing et al.  obtained from the Campylobacter jejuni MLST database . Each strain name is followed by the number of the clonal complex to which that strain belongs and the source from which it was isolated. The two most distantly related strains in the virulence gene RFLP analysis, D0121 and D2600, had a Jaccard similarity coefficient of 0.45.