FIG 1.

Phylogenetic trees and sequence alignments of ctxB, rstR, and tcpA. (A, C, and D) Phylogenetic trees of ctxB, rstR, and tcpA, respectively. (B) Alignment of deduced amino acid sequences of ctxB from V. cholerae strains. The serogroups and GenBank accession numbers of the reference sequences for ctxB, rstR, and tcpA are shown in parentheses in panels A, C, and D. Sequence characters in black on a white background represent rare substitutions; sequence characters in white on a black background represent identical sequences in all genotypes; sequence characters in white on a gray background represent common substitutions. El, El Tor biotype; CL, classical biotype.