Bactericidal effect of nisin and reuterin on methicillin-resistant Staphylococcus aureu(MRSA) and S. aureus ATCC 25937

Abstract

Nisin and reuterin are used in processed foods as preservatives. They are considered to be potential sources of natural antibiotics for the treatment of food contaminated by antibiotic-resistant bacteria, such as methicillin-resistant Staphylococcus aureus. We try to compare the best effect of both nisin and reuterin on the growth of methicillin-resistant S. aureus (MRSA) and S. aureus ATCC 25923. The results indicated that nisin at different concentrations inhibited the growth of methicillin-resistant S. aureus after 4 h, whereas after 12 and 24 h, the bacteria have regrown and reactivated. S. aureus ATCC 25923 was not affected by nisin concentration and has continuously grew at all times. Reuterin at different concentrations gradually inhibited the growth of methicillin-resistant S. aureus and S. aureus ATCC 25923 and declined after 12 h for both. Therefore, it can be deduced that nisin alone exerts a bacteriostatic effect on methicillin-resistant S. aureus but not on S. aureus ATCC 25923. Reuterin is considered as bactericidal effect on both microorganisms. The combination of nisin at a concentration of 25.6 and reuterin at a concentration of 5.2 mg/mL exerted a bactericidal effect on both microorganisms. By mixing nisin with reuterin, it can be more active against both microorganisms.