EFFECTS OF AMINOGLYCOSIDE, BETA-LACTAM AND QUINOLONE ANTIBIOTICS ON PSEUDOMONAS-AERUGINOSA ENZYMES

Aminoglycoside (tobramycin, netilmicin, amikacin), beta-lactam (ceftazidime, imipenem, azlocillin), as well as quinolone (ciprofloxacin, ofloxacin, pefloxacin) antibiotics in all sub-MICs, but mainly at the level of 1/4 of the MICs, significantly decreased P. aeruginosa phospholipase C activity. Netilmicin, imipenem and ciprofloxacin most strongly reduced the tested activity at this level of antibiotic concentrations. 1/4 of the MICs of the studied antibiotics were also the most effective in suppression of elastase activity, but the degree of this inhibition was not as high as that for phospholipase C activity. Tobramycin and imipenem reduced this activity in all sub-MICs. Ofloxacin (1/4 of the MIG) caused the highest suppression of elastase activity. Proteinase activity was decreased after treatment with all tested sub-MICs of tobramycin and imipenem. The most significant suppression of activity was achieved by the effect of ciprofloxacin (1/4 of the MIC).