A Study of the Effect of Silver Nanoparticles on Extended Spectrum Beta-Lactamase Producing Klebsiella Strains

Wide use of beta-lactam antibiotics increases bacterial resistance to these groups of antibiotics in pathogen bacteria through production of beta-lactamase enzyme. The present study was carried out with the aim of evaluating the isolation of ESBL producing Klebsiella spp. in clinical specimens and investigating the effect of silver nanoparticles on them. A total of 61 clinical Klebsiella isolates were examined in terms of production of extended spectrum beta-lactamase (ESBL) through disk diffusion method using the antibiotics cefixime, ceftriaxone, ceftazidime, as well as beta-lactamase inhibitor clavulanic acid, and the antibiotics’ minimal inhibitory concentration (MIC) values were determined by agar dilution method. Then, ESBL production was examined using standard ESBL disk for detection of deta-lactamase through DDT (double disk approximation test) method. Subsequently, the effect of different concentrations of nanosilver solution on isolated bacteria was studied. Student t-test was used for analysis of the data. Out of 61 multidrug resistant Klebsiella isolates, 51 (60.83%) Klebsiella pneumonea and 10 (39.16%) Klebsiella oxytoca were recognized. All samples were demonstrated to be positive in double disk method for proving ESBL production, and were sensitive to the nanosilver solution with a concentration of 500ppm. The obtained findings showed that increase in the concentration of nanosilver solutions had a direct correlation with inhibition zone diameter of ESBL producing Klebsiella spp in vitro and in completely aseptic condition. If it is proved that nanosilver solutions are non-toxic in vivo, they could be used as a new effective alternative to antibiotics.