Erwinia carotovora ssp. atroseptica SCRI1043 is a plant pathogenic bacterium. Many species of enterobacteria including Erwinia sp. can induce the onset or the progression of opportunistic or persistent infections in humans. The existence of these bacteria within different ecological niches is related to their significant adaptive potential. The triggering of adaptive reactions, which are needed for bacterial persistence, is controlled in many cases by intercellular communication; hence, the ability to survive under unfavourable conditions is regulated in a cell-density-dependent manner. In this study, we showed that, during starvation of E. carotovora ssp. atroseptica SCRI1043, the initial stage of the response to stress was stabilization of the density of culturable cells in the range 10(6)-10(7) CFU mL(-1). The number of culturable cells increased (up to approximately 10(6) CFU mL(-1)) when cultures were inoculated at a low cell density (10(3)-10(5) CFU mL(-1)), and at the same time, acylhomoserine lactone (AHL)-dependent quorum sensing was activated. Our results showed that the regulation of cell density in starving populations of E. carotovora ssp. atroseptica SCRI1043 occurred and this regulation was carried out with the involvement of the cell-to-cell communication.