Given the dual action of prophages in acquisition of DNA and
killing of phage-susceptible cells, we hypothesized that autotransduction
could be advantageous for the lysogen during
establishment in a new environment with a pre-existing bacterial
population. For this we chose to investigate how lysogenic 8325-
SR competed against another phage-susceptible strain (USA300)
when this was already growing on the surface of agar plates, by
analysing CFU of both strains over time. After 1 day, the initial
exponential growth had ceased for both strains and the number of
CFUs gradually declined over the next 16 days. Although the
lysogen 8325-SR experienced a 200-fold reduction during the
16 days of the experiment, the USA300 population experienced
a 5,000-fold decline in the presence of 8325-SR (Fig. 3a).