DiversiLab rep-PCR dendrogram. Representative strains are shown to demonstrate the segregation of different serotypes by rep-PCR. Cluster A was comprised of duplicate serovars of subspecies I (Typhimurium, Choleraesuis, and Enteritidis), while cluster B included duplicate serovars of subspecies III (Arizonae). Within each individual serovar, analyzed in triplicates, >94% DNA similarity was observed. More than 70% DNA relatedness was noted between serovars of the same serovars. The scale at the bottom indicates the percentage similarity among fingerprints of each genotype.