Bacteriostatic Potency of Fe2O3 Against Enterococcus faecalis in Synergy with Antibiotics by DDST Method

  In this study, bacteriostatic potency of the Iron oxide nanoparticles against Enterococcus faecalis (E. faecalis) (a clinical sample and the ATCC11700 strain) was investigated. Nanoparticles’ bacteriostatic concentration was determined and used to appraise the characteristics of the Iron Oxide (Fe2O3) against the isolates. Antimicrobial examinations with 108cfu.ml-1 were performed at the baseline. Due to evaluation level of potency, after performing Minimum Inhibitory Concentration (MIC), the assessment of death kinetic and susceptibility constant of nanoparticles was done by suspension at two MICs in 0 to 360 min treatment time. Fe2O3 nanoparticles in size range of 10-50 nm demonstrated the most effective susceptibility reaction against E. faecalis and ATCC11700 strain in Z=78.125 ml/μg-1 and 39.0625 ml/μg-1, respectively. The kinetic reaction of E. faecalis against Fe2O3 suspension was supposed to be decreased through the elapse of treatment time, whereas increased concentration was along with bacteria growth after a certain time. So, the efficient concentration of nanoparticles was applied with semi-sensitive and antibiotic resistant for both strains. However, synergism of Fe2O3 nanoparticles with Ceftazidime and Clindamycin revealed a higher susceptibility compared with Fe2O3 nanoparticles alone against E. faecalis. The experimental results reveal that Fe2O3 has a strong antimicrobial effect at a certain concentration over the time so could potentially be used for bacterial inhibition and this feature will be strengthened in combination with antibiotics.