ABSTRACT

Objectives: To compare the in vitro activity of mutacins D-123.1 and F-59.1 against different bacteria including antibiotic-resistant strains, in order to evaluate their application potential.

Design and Methods: The antibacterial activity spectrum of purified F-59.1 and the MIC and MBC of F-59.1 and D-123.1 against target bacteria were determined.

Results: Most bacteria were inhibited by the purified mutacins. Mutacin F-59.1 shows a relatively wide activity spectrum. Mutacin D-123.1 has low Minimum Inhibitory Concentrations [MICs] (0.25-4 μg/ml) against human pathogens while F-59.1 has higher MICs (3.2-12.8 μg/ml) mainly against food-borne pathogens.

Conclusion: The effectiveness of mutacins D-123.1 and F-59.1 against human and food-borne pathogens is demonstrated. Mutacin D-123.1 shows potential as a new antibiotic while F-59.1 shows promising application in food products.

Abbreviations: MALDI-TOF MS, matrix assisted laser desorption ionisation-time of flight mass spectrometry; MB(I)C, minimum bactericidal (inhibitory) concentrations; OD, optical density; RPHPLC, reverse-phase high-pressure liquid chromatography; TSBYE, trypticase soy broth yeast extract.