[Uncultured status of pathogenic bacteria: known and possible factors of reversible process induction]

Reviews published reports and authors' own data on the properties of unculturable bacteria, effects of environmental factors on the time course of transition in an unculturable state of different bacterial cells. Special attention is paid to reverse transfer of bacteria from unculturable to normal vegetative state. Conditions of inducing reverse transfer in in vitro laboratory conditions under different conditions of culturing and in vivo and injection of inoculates of uncultured forms of initially virulent bacteria to susceptible hosts are discussed. Probable role of some cytokinetic factors inducing transfer of bacteria from uncultured to cultured state during their transition from the environment into a host is discussed.