Akademik Veri Yönetim Sistemi
TURKIYE KLINIKLERI TIP BILIMLERI DERGISI, cilt.32, sa.5, ss.1319-1326, 2012 (SCI-Expanded)
Objective: Pseudomonas aeruginosa (P. aeruginosa) is a human opportunistic pathogen that colonizes biotic and abiotic surfaces and has been emerging as an important source of nosocomial infections. Quorum sensing (QS) systems are interbacterial signaling systems and have a role in the regulation of virulence factors. These systems are efficient with extracellular signaling molecules and are used to detect the local concentration of bacteria. Material and Methods: Minimum inhibitory concentrations (MICs) for aminoglycosides (gentamicin, amikacin and netilmicin) of two clinical isolates from catheter site and (Cl, C2) an ATCC 27853 P. aeruginosa isolate were determined. Then the relationship between las and rhl QS systems and biofilm formation, gelatinase, alkaline protease, oxidase, catalase, which are extracellular virulence factors of P. aeruginosa were investigated at these MIC and sub-MIC levels. Results: Biofilm formation, and protease-gelatinase activities were positive under all concentrations of aminoglycosides (gentamicin, amikacin, and netilmicin) at 18 hours of the experiments for all Pseudomonas strains. Enzymatic activities of catalase and oxidase, and the signal molecules of the QS systems were present under MIC and sub-MIC concentrations. Conclusion: Our study showed that different aminoglycoside (gentamicin, amikacin, netilmicin) concentrations had different effects on "bacterial phenotypic changes". According to our results, different "chemical microenvironments" have different effects on the "bacterial behavior". On the next step of translational experiments, it may be useful to organize experimental infection models in animals, against different susceptible antibiotics.