An in vitro investigation of effect of chitosan and turmeric (Curcuma longa) extract against the planktonic and biofilm forms of the multiple drug resistant bacteria

Background and Aim : Turmeric belongs to the ginger family, has been traditionally used as a spice and medicine from ancient times and its potential in other fields has been harnessed in recent years. In this study, we aimed to investigate the antibacterial and anti-biofilm effects of turmeric and chitosan against the planktonic and biofilm forms of the multiple drug-resistant (MDR) bacteria.Methods : Forty MDR strains including ۱۰ MRSA strains, ۱۰ strains of CRP, ۱۰ strains of CRE and ۱۰ strains of AmpC-producing Enterobacteriaceae obtained from various clinical specimens. MDR strains were confirmed by the phenotypic and genotypic tests. The broth micro-dilution method was used to investigate the minimum inhibitory concentration of turmeric aqueous extract and chitosan. To investigate the synergistic effect of the combination of these natural compounds, we used the checkerboard assay.Results : The turmeric and chitosan showed inhibitory effects on MDR bacteria, especially on the planktonic form of MRSA as a Gram-positive compared with tested Gram-negative bacteria (carbapenem-resistant Pseudomonas, carbapenem-resistant Enterobacteriaceae, and AmpC-producing Enterobacteriaceae). The antibiofilm effect of turmeric and chitosan were more found in carbapenem-resistant Pseudomonas isolates. There was no significant difference between the tested Gram-negative bacteria because most of the tested strains were inhibited in ۵۱۲ µg/mL and ۱۰۲۴ µg/mL concentrations of chitosan and turmeric aqueous extract.Conclusion : The results of this study demonstrate that turmeric and chitosan substances have an in vitro inhibitory effect on the planktonic and biofilm form of MDR bacteria. Further examination is needed to completely understand turmeric aqueous and chitosan to improve formulations to make it usable as a drug.

Keywords:

Biofilm , Chitosan , Multiple drug-resistant , Turmeric