Chitosan-Thioglycolic Acid as a Versatile Antimicrobial Agent

Abstract

As functionalized chitosans hold great potential for the development of effective and broad-spectrum antibiotics, representative chitosan derivatives were tested for antimicrobial activity in neutral media: trimethyl chitosan (TMC), carboxy-methyl chitosan (CMC), and chitosan-thioglycolic acid (TGA; medium molecular weight: MMW-TGA; low molecular weight: LMW-TGA). Colony forming assays indicated that LMW-TGA displayed superior antimicrobial activity over the other derivatives tested: a 30 min incubation killed 100% Streptococcus sobrinus (Gram-positive bacteria) and reduced colony counts by 99.99% in Neisseria subflava (Gram-negative bacteria) and 99.97% in Candida albicans (fungi). To elucidate LMW-TGA effects at the cellular level, microscopic studies were performed. Use of fluorescein isothiocyanate (FITC)-labeled chitosan derivates in confocal microscopy showed that LMW-TGA attaches to microbial cell walls, while transmission electron microscopy indicated that this derivative severely affects cell wall integrity and intracellular ultrastructure in all species tested. We therefore propose LMW-TGA as a promising and effective broad-band antimicrobial compound.

Chitosan-Polyoxometalate Nanocomposites: Synthesis, Characterization and Application as Antimicrobial Agents

“…CS has been reported to suit water disinfection applications when incorporated into membranes, sponges, or surface coatings of water storage systems [31]. Because of its activity against bacteria, viruses and fungi, and its low toxicity towards animals and humans, CS is widely employed as a cheap and abundant antimicrobial agent [32,33].…”

Chitosan, Chitosan Derivatives and their Biomedical Applications

“…Chitosan modiied with monomethyl fumaric acid presented antibacterial activity against Gram-positive and Gram-negative bacteria [85]. Other chitosan derivatives with antimicrobial activity included the following: chitosan modiied with thioglycolic acid [86] and chitosan with polyethylene glycol diacrylate (PEGDA) [87].…”

Preparation of Chitosan Material and its Antifungal Activity for Bamboo

“…Chitosan has emerged not only as a promising and economic source for efficient and versatile antimicrobial material but also as a biocompatible and biodegradable polymer with various applications (Geisberger et al, 2013). It has been extensively used as edible coatings to preserve the quality of many foods (Huang et al, 2012) and as a bioactive fungicide (EI Ghaouth et al, 1992).…”