FIG. 7.

Growth advantage of other V. cholerae strains. (A) The V. cholerae El Tor strains E7946 and C6709 and O139 strain SG24 were grown in monocultures or cocultured with classical O395 (1:1), and the number of CFU of each strain was determined at regular intervals. Circles and squares represent the numbers of CFU of each strain in individual cultures and mixed cultures, respectively. (B) The El Tor strains C6709 (a) and E7946 (b) and O139 strain SG24 (c) were grown for 24 h in LB medium monocultures, centrifuged, washed, and suspended in equal volumes of 24-h culture filtrates of classical strain O395 or their own culture filtrates; the number of CFU per ml of each strain was then determined after 6 h. Growth yields were determined by dividing the number of cells of each strain in O395 culture filtrates by the number of cells in their own culture filtrates. All experiments were performed three times, and results are represented as means ± standard deviations.