Is Phase Variation in Bordetella Caused by Mutation and Selection?

Abstract

In vitro growth conditions of B. bronchiseptica led to an enrichment of phase variants. The frequency of phase variation was about 10-6 per cell per generation. Therefore phase variation in Bordetella may result from a random mutation in a controlling region, followed by selection. Phase variation may result in the simultaneous loss of several putative virulence determinants such as toxins, adenylate cyclase, hemolysins and agglutinins.