Fig. 2.
Genetic mapping of CTXΦ lacking RS1 in V. cholerae O1 biotype El Tor strains isolated in Mexico during 2004–2008. The deduced genetic organization shows integration of an additional truncated CTXΦ in the upstream region of the CTXΦ in the large chromosome (Chr I) of V. cholerae whereas the dif2 site in the small chromosome did not harbor CTXΦ. Arrows indicate transcription directions of each of the genes in the CTXΦ and flanking regions. The map is without a scale bar. rstRET (blue arrow), El Tor type rtsR; ctxBET (green arrow), El Tor type ctxB; orfU (red box), truncated orfU subunit; TLC, toxin-linked cryptic; RTX, repeat in toxin. Locations of primers are also shown.