FIG. 2.

Competition between El Tor and classical biotype strains in the death phase. The El Tor N16961 and classical O395 strains were grown separately for 24 h and then mixed at a ratio of 1:1. The individual cultures and the mixed culture were incubated at 37°C with aeration for a further 12 h, and the numbers of CFU of each strain in the individual and mixed cultures were determined at regular intervals. Circles and squares represent the number of CFU per ml of each strain in individual cultures and mixed cultures, respectively.