Application of chitosan-alginate microspheres for the sustained release of bacteriophage in simulated gastrointestinal conditions

초록

This study was designed to evaluate the acid stability, release property and antimicrobial efficacy of Escherichia coli O157:H7 bacteriophages encapsulated in chitosan-alginate microspheres under the simulated gastrointestinal conditions. The bacteriophages belonging to Myoviridae family were stable at the pH above 4 in trypticase soy broth. The chitosan-alginate microspheres exhibited protective effect on the viability of bacteriophages in the simulated gastric conditions at pH 2.0 and pH 2.5, showing 4.8 and 5.6 log PFUmL(-1), respectively, after 1h of incubation at 37 degrees C. The release per cent of bacteriophages from microspheres gradually increased up to 65% in the simulated intestinal condition (pH 7.5) at 37 degrees C for 6h. The lytic efficacy of chitosan- and alginate-encapsulated bacteriophages against E.coli O157:H7 was significantly maintained in the simulated intestinal conditions to 10h of incubation (1.3 log reduction). The results suggest that the chitosan-alginate microspheres can be used as a reliable delivery system for bacteriophages.

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