POSTANTIBIOTIC EFFECT OF SOME ANTIBIOTICS ON THE METABOLISM OF PSEUDOMONAS-AERUGINOSA

The influence of the postantibiotic effects (PAEs) of ciprofloxacin, p efloxacin, imipenem, meropenem and amikacin in the suprainhibitory con centrations (2 x and 4 x MIC) on the metabolic processes of P. aerugin osa was studied. The synthesis of macromolecules was expressed by infl uencing of the incorporation rate of [C-14] adenine and [C-14] leucine . Remarkable affecting of both biosynthetic processes evoked the supra inhibitory concentration 4 x MIC of meropenem by inhibition of the nuc leic acids synthesis to 76.1% and proteins synthesis to 61.1% against the control. The suprainhibitory concentration 3 x MIC of both pefloxa cin and ciprofloxacin affected the highest suppression of the endogeno us respiration to 16.5% and to 20.3%, respectively. The respiration wa s influenced the least after the effect of meropenem in the both supra inhibitory concentrations tested. According to our knowledge, this is first report about the evaluation of the endogenous respiration after PAE. In this study we demonstrated the inhibitory effects of 4 x MIC c oncentration of antibiotics studied on the metabolic processes of P. a eruginosa. The results suggest a multiple mechanism for the PAE.