Genetic relationships, geographical origins and host fish species of the 230 F. psychrophilum isolates with MLST profiles available. The tree was built based on the number of shared allele types (AT) using hierarchical clustering and a single link aggregation criterion. This choice ensures a relative robustness with respect to recombination as well as consistency with the eBURST diagram and the definition of clonal complexes. The circle associated with each sequence type (ST) reflects its number of occurrences (size) and geographical origin (color). The most frequent fish host for each ST is reported on the side together with its relative frequency (between parentheses).