Mutual kinetics of agent ? host relation in the development of pseudomonas aeruginosa infection

Pseudomonas aeruginosa is a human opportunistic pathogen that colonises biotic and abiotic surfaces and has been emerging as an important source of nosocomial infections in Turkiye as well as any other country in the world.It was shown that quorum sensing is an inter bacterial signalling system and is efficient on the regulation of virulence factors. These systems are efficient with extracellular signalling molecules and are used in order to detect the local concentration of bacteria.In planning the therapy it is getting necessary to identify the relationship between the host (in vitro system) and the Pseudomonas following the exposure of the decreasing concentrations of antibiotics (subminimal inhibitory concentrations = sub-MICs).Today it is thought that the therapy of Pseudomonas infections can not be realized only by the antibacterials but the genotyping and phenotyping are the main stones of this multifactorial therapy.In this study, following the determinations of minimum inhibitor concentrations (MICs) of gentamicin, netilmicin and amikacin; biofilm formation, alkalene protease, gelatinase, catalase productions of the two clinically isolated Pseudomonas aeruginosa (one is QS positive / one is QS negative) and standard ATCC 27853 strains (QS positive), that were exposed to MIC and sub-MICs of these antibiotics, were determined in identified time intervals.As a result, it is suggested that factors like the relation between QS positive / QS negative Pseudomonas aeruginosa strains with the host and the possible effect of QS systems on pathogenicity may play important roles in understanding the effect of QS in the new, possible therapeutic targets.Keywords: Pseudomonas aeruginosa, ?Quorum Sensing?, subminimal inhibitory concentrations