Antimicrobial efficacy and safety of mucoadhesive exopolymer produced by Acinetobacter haemolyticus

This study evaluated five extracellular polymers of bacterial origin possessing mucoadhesive properties for their antimicrobial properties and toxicological characteristics. Of the five tested mucoadhesive biopolymers, the extracellular polymer produced by a strain of Acinetobacter haemolyticus exhibited broad antimicrobial efficacy towards Yersinia enterocolitica, Salmonella typhimurium, Listeria monocytogenes, Escherichia coli O157:H7 and Bacillus subtilis. Significant (p < 0.05) inhibition of gram negative bacterial pathogens followed by gram positives were observed with the biopolymer at a dose of 40-60 μg ml-1 at ambient temperature. The cytotoxicity under in vitro conditions and oral toxicity in murine models was also evaluated. The biopolymer did not elicit either haemolytic activity or toxicity in RAW 264.7 cell lines. Haemotological, histopathological and general examinations indicated no adverse effects in Swiss albino mice fed with the biopolymer (120 mg kg-1 body weight-1 day1) over a period of 30 days. These results suggested that the biopolymer was well tolerated without any signs of toxicity and may have several potential biomedical applications where disinfection is desired.