FIG 1.

OmpR controls colony morphology and phase variation. A. baumannii colonies were photographed through a dissecting scope with oblique illumination from below after 24 h of growth. (A) Wild-type strain AB5075 opaque variant; (B) wild-type strain AB5075 translucent variant; (C) KT4 (ΔompR) mutant. (D) Phase variation frequency represented as percentages of translucent variants in 24-h-old colonies of A. baumannii opaque colonies. Data are presented as the averages ± the standard deviations for six separate colonies. (E) Phase variation frequency represented as percentages of opaque variants in 24-h-old colonies of A. baumannii translucent colonies. Data are presented as the averages ± the standard deviations for six separate colonies. ***, P < 0.0001.