FIG. 2.

Phylogenetic distribution of virulence genes and virulence of different S. enterica subspecies I serotypes in mice and humans. The bacterial isolates shown in this figure have been described previously (23). The left side shows a dendrogram reflecting the phylogenetic relatedness of these strains as reported by Selander and coworkers (23). ET, enzyme type determined by multilocus enzyme electrophoresis (23). The distribution of the spv (Salmonella plasmid virulence), lpf (long polar fimbriae), sef (S. enterica serotype Enteritidis fimbriae), agf (thin aggregative fimbriae), fim (type 1 fimbriae), and pef (plasmid-encoded fimbriae) operons among these isolates has been determined previously (12, 17). The presence in these strains of sequences related to viaB (Vi capsular antigen) is described elsewhere (107). Virulence of these isolates in humans or mice has been reported recently (17, 107). a, although missing in this strain, virulence plasmids are present in most isolates of this serotype.