Extraction and characterization of antibacterial marine polysaccharide K-Carrageenan from Kappaphycus alvarezii against multidrug-resistant wound associated bacteria

Antimicrobial resistance (AMR)-related diseases have ruined the lives of many people and the multidrug-resistant bacterial infections have a key role in the mortality associated with antimicrobial resistance (AMR). The focus was shifted to natural resources for the development of antimicrobial compounds in order to overcome this resistance. In this study K-Carrageenan was extracted from Kappaphycus alvarezii and characterized by the Fourier transform infrared (FTIR), Gas chromatography mass spectrometry (GC-MS), Liquid chromatography mass spectrum (LC-MS) and Nuclear Magnetic Resonance (H-NMR) analysis. The antibacterial property of carrageenan was tested using the Minimum Inhibitory Concentration and the bacterial cell growth rate. The results showed higher antibacterial activity of K-Carrageenan against S. aureus, E. coli, P. aeruginosa, P. vulgaris, and V. parahaemolyticus. Well diffusion method, growth curve studies, anti-biofilm studies were done in K-Carrageenan. Intracellular protein molecules and nucleic acid leakage confirmed that 100 µg/mL of K-Carrageenan increase membrane permeability, leading to cell death. At a concentration of 100 µg/mL of K-Carrageenan was non-cytotoxic to RBCs cells and promoted antibacterial and antibiofilm properties against the wound pathogens. From this study, these results determine the strong potential of K-Carrageenan treating MDR bacteria-infected chronic wounds.