Evaluation of antimicrobial efficacy of 1% phytic acid incorporated with 0.2% chitosan nanoparticles against Enterococcus faecalis: An in vitro study

Abstract

ABSTRACT Aim: The aim of the study was to evaluate the antimicrobial activity of 1% phytic acid and ethylenediaminetetraacetic acid (EDTA) incorporated with 0.2% of chitosan nanoparticles (Csnps) against Enterococcus faecalis (E. faecalis) by agar diffusion and biofilm model. Materials and Methods: Antimicrobial efficacy was evaluated in two stages: (i) agar well-diffusion method and (ii) biofilm model. E faecalis (American Type Culture Collection 29212) strain was subcultured and grown on the blood agar plates, followed by placement of test solutions in punched holes (5 mm diameter) and incubated for 24 h at 37°C as follows (n = 10): Group 1: normal saline (control), Group 2: EDTA, Group 3: EDTA +0.2% Csnps, Group 4: 1% phytic acid, and Group 5: 1% phytic acid + 0.2% Csnps followed by measurement of inhibition zone. For biofilm model, standardized dentin blocks were prepared from fifty human-extracted single-rooted premolars and sterilized and contaminated for 2 weeks by transferring 50 μl of bacterial inoculum to sterilized test tubes containing 1 mL of Mueller–Hinton agar broth (MHA) with alternate day replenishment of the broth. The specimens were cleaned and subjected to test solutions as mentioned above. Serial decimal dilutions were prepared, followed by inoculation on MHA plates and incubation for 24 h, accompanied by counting of the colonies per milliliter (colony-forming unit per milliliter). Results were statistically analyzed using one-way analysis of variance and Post hoc Tukey’s tests (P < 0.05). Results: Phytic acid incorporated with Csnps exhibited a greater zone of inhibition and least colony count against E. faecalis biofilm compared to all groups. Conclusion: Combination of Csnps and phytic acid exhibits effective antimicrobial activity against E. faecalis.