Repression of adenylate cyclase in the genus Bordetella

Virulent phase I strains of Bordetella pertussis synthesize the regulatory metabolite adenosine 3',5'-cyclic monophosphate (cAMP); whereas, non-virulent phase IV strains are unable to do so. These findings were confirmed and extended using additional strains of B. pertussis as well as strains of Bordetella parapertussis and Bordetella bronchiseptica. Levels of adenylate cyclase activity and subsequent cAMP production were found to correlate. High adenylate cyclase activity during exponential phase was followed by an accumulation of cAMP during late log and throughout stationary phase. Measurements obtained during the X- to C-mode transition process indicated that adenylate cyclase is subject to complete repression.