Bacterial communication and possible application in control and therapy ofbacterial diseases

Biological processes such as control of bioluminescence in Vibrio fisherii and Vibrio harveyi, expression of virulence factors in Pseudomonas aerugino sa and Erwinia carotovora or conjugative transfer of the Ti plasmid in Agro bacterium tumefaciens are dependent on the production and sensing of specif ic secondary metabolites derived from the structure of N-acyl homoserine la ctone. These metabolites are released and sensed by bacterial populations w hich in turn modify their metabolism accordingly. In certain bacterial spec ies, virulence is under the control of these metabolites, in genomes of Sal monella typhimuirum and E.coli homologous systems with so far unknown funct ion have been identified. This shows that communication by secondary metabo lites is widespread in bacteria. Furthemore, host organism have been shown to respond to these metabolites by non-specific immune reactions. Understan ding the biological role of this communication could enable specific modifi cation of behaviour of bacterial populations and thus open a way to new the rapeutic measures. All of this becomes even more important in a time when a ntibiotic resistance in bacteria increases and new ways of prevention and c ontrol of infectious diseases are sought.