The effect of antibacterial synergism of silver nanoparticles with extract of Urtica dioica and Allium hirtifolum against multidrug resistant klebsiella (MDR) isolated from ICU patients

Background: Because most bacteria responsible for hospital infections are resistant to common antibiotics, the tendency to produce effective and nontoxic anti-microbial drugs have increased. Therefore, it is attempted to substitute antibiotics with natural products, such as nanoparticles and plant extracts. The aim of this study was to investigate the synergistic antibacterial effects of silver nanoparticles with extracts of nettle and shallot plants against multi drug resistant (MDR) kebsiella. Materials and methods: Of 360 clinical samples, 112 kebsiella were isolated from ICU hospitalized patients. The klebsiella isolates were identified by biochemical tests. The antibiotic susceptibility of isolates was determined using disc diffusion method. Minimum inhibitory concentration of silver nanoparticles, nettle and shallot extracts against resistant isolates was assessed by broth microdilution method and their synergitic effects were determined using checkerboard method. Also the fractional inhibition concentration (FIC) was calculated. Results: The silver nanoparticles were more effective than plant extracts against MDR isolates. The use of silver nanoparticles and shallot extract together led to synergistic effect on both MDR klebsiella isolate and Klebsiella pneumoniae ATCC 1290. In addition, the use of the silver nanoparticles and nettel extract led to synergistic effect on MDR isolate of klebsiella and additive effect ATCC isolate. Conclusion: Due to good antibacterial effect of AgNPs, shallot and nettle extracts on resistant klebsiella isolates and their affordable production, they can be exploited in addition to antibiotic treatments. Keywords: Silver nanoparticles, Shallot extract, Nettle extract, Klebsiella, MDR.