The present invention relates to a method of preventing or treating a disease caused by bacterial infection by administering an effective amount of a modulator of bacterial adenylyl cyclase. The invention also provides pharmaceutical compositions useful for preventing or treating a disease, with the compositions containing a therapeutically effective amount of a modulator of bacterial adenylyl cyclase. The invention also provides screening methods for identifying selective modulators of bacterial adenylyl cyclase that do not substantially modulate adenylyl cyclase of the subject. The invention also provides methods for culturing bacterial pathogens and methods for inducing the pathogenic state in vitro.