[Interactions between bacteria of the genus Yersinia in a water environment]

Under the conditions of a prolonged experiment in sterile water at 4-6 degrees with no outside supply of any substances pathogenic Y.pseudotuberculosis, Y.enterocolitica and other Yersinia species in pure and binary cultures remained viable for the period of 12-24 months (the term of observation). In monocultures, all Yersinia actually returned to their initial amounts. In associations with Y.enterocolitica O:3, Y.frederiksenii and Y.intermedia, a delay in the lag-phase (1-2 weeks) was observed in Y.pseudotuberculosis, while in the other pair they stimulated the lag- and log-phase in Y.enterocolitica O:8. In other associations, the growth of different cultures was balanced; 12 and 24 months later their amount characteristics exceeded the initial ones by 2-4.9 and 1-3.5 orders respectively. The possibility of interaction with the signs of protocooperation between different Yersinia cells under natural conditions is discussed.