Gamaleya Research Institute of Epidemiology and Microbiology, Moscow, Russia
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-homoserine lactone (Ñ4), hexanoyl-homoserine lactone (Ñ6) and octanoyl-homoserine lactone (Ñ8) 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 Ñ4, Ñ6 and Ñ8 lactones when introduced simultaneously. Strengthening of virulence of the P.aeruginosa strain under the action of lactone Ñ6 and simultaneous action of Ñ4, Ñ6 and Ñ8 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.
Zh. Mikrobiol. (Moscow), 2006, No. 4, P. 32—37