[The role of "quorum sensing" regulation system in symbiotic interaction of bacteria Burkholderia cepacia and Pseudomonas aeruginosa during mixed infection].

: Data concerning mechanisms of strengthening virulence of bacteria B.cepacia and P.aeruginosa during experimental mixed-infection are submitted. Results of in vitro studies of acylhomoserine lactones (AHL) with various length of a carbon lateral circuit have shown that butanoyl-homoser-ine lactone (C4), hexanoyl-homoserine lactone (C6) and octanoyl-homoserine lactone (C8) separately and in various combinations display different effects on growth of bacteria, formation of colonies and production of pathogenicity factors. Experiments on animals have shown strengthening virulence of bacteria B.cepacia by C4, C6 and C8 lactones when introduced simultaneously. Strengthening of virulence of the P.aeruginosa strain under the action of lactone C6 and simultaneous action of C4, C6 and C8 lactones was observed. The data obtained give grounds for assumption, that bacteria may use exogenous lactones, including those produced by closely related bacteria, during their life cycle.