The Dienes phenomenon: identification of the determinants of compatibility.

Two hundred and four isolates of swarming strains of Proteus species which had been typed for their ability to produce bacteriocin (proticine) and also their proticine sensitivity (P/S typing) were tested in all combinations for their Dienes compatibility with each other. Ninety-eight distinct Dienes compatibility groups were found. Physiological and genetic experiments supported the evidence of typing results that, irrespective of species, both the type of proticine a strain produces (P type) and the sensitivity of the strain to proticine (S type) were determinants of Dienes compatibility. Strains showing compatibility in the Dienes test were of the same P/S type, whereas those of different P/S types were incompatible.