Investigation of the effect of n-acetylcysteine on mic values of various antibiotics in pseudomonas aeruginosa strains isolated from clinical specimens

P. aeruginosa is one of the most important causes of nosocomial infections. As well as viral factors make Pseudomonas important in nosocomial infections, plasmid-mediated factors and beta-lactamases in plasmid control are also present. Acetylcysteine is the N-acetylated derivative of L-cysteine, a natural amino acid, which is the mucolytic agent. In this study, it was aimed to determine the effect of N-acetylcysteine (NAC) on Minimal Inhibitory Concentration (MIC) values of P. aeruginosa strains isolated from clinical samples of patients. 50 P. aeruginosa strains were considered. MIC values antibiotics were investigated with liquid micro diffusion method according to Clinical and Laboratory Standards Institute (CLSI) recommendations. Then the MIC values were re-determined via combining the same antibiotics with NAC (10 mM, 1.6 mg/ml). P. aeruginosa ATCC 27853 was used as a control strain in our study. The mean MIC value of 37 P. aeruginosa strains susceptible to colistin determined as 1.07±0.65 µg/mL and the mean MIC value of Colistin+NAC combination as 1.62±1.36 (p<0.05), the mean MIC value of 11 P. aeruginosa strains susceptible to ciprofloxacin is 0.78±0.31 µg/mL and mean MIC value of the ciprofloxacin+NAC combination is 1.36±.63 µg/mL (p<0.05), the mean MIC value of 42 P. aeruginosa strains susceptible to amikacin was determined as 6.80±1.92 µg/mL and amikacin+NAC combination as 8.09±3.36 µg/mL (p<0.05), the mean MIC value of 40 P. aeruginosa strains susceptible to meropenem was determined as 2.52±1.36 µg/mL and amikacin+NAC combination as 53.70±17.65 µg/mL (p<0.05), the mean MIC value of 37 P. aeruginosa strains susceptible to ceftazidime was determined as 6.05±2.18 µg/mL and amikacin+NAC combination as 10.05±5.76 µg/mL (p<0.05). The increase in MIC values of the combination of studied antibiotics with NAC is conspicuous and the most significant increase was observed in meropenem+NAC combination. This should be taken into consideration in clinical use. Also, further studies should be carried out on this issue