Bactericidal effect of nisin and reuterin on methicillin-resistant Staphylococcus aureus (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.

Nisin: Prerequisites and Prospects for Application in the Medical Field

“…However, it should be noted that there are conflicting data regarding certain bacteria. On the one hand, the antimicrobial efficacy of nisin against the entire genus Staphylococcus is reported, on the other hand, there is evidence of its selective activity against representatives of this genus (e.g., nisin exhibits bacteriostatic activity against MRSA and does not inhibit the growth of S. aureus ATCC 25937) [4,5,9,13,27,[32][33][34][35][36]. Gram-negative bacteria are usually much less sensitive or resistant to nisin.…”

“…Nisin has attracted considerable attention due to its broad spectrum of antimicrobial activity, low probability of developing bacterial resistance, and low cellular cytotoxicity at antimicrobial concentrations [5]. A number of studies have demonstrated antimicrobial and antibiofilm activity of nisin against multidrug-resistant S. pneumoniae, MRSA, multidrug-resistant P. aeruginosa, and vancomycin-resistant enterococci (VRE) [5,13,19,20,32,34,49,50]. Lipid II is also a molecular target for vancomycin, the glycopeptide antibiotic of the last resort treatment of infection caused by certain antibiotic-resistant gram-positive bacteria, including MRSA.…”

“…The antibacterial activity of nisin can be enhanced when combined with other antimicrobials such as buforin I, reuterin, 3-phenyllactic acid, 2, 3-dihydroxybenzoic acid, chelators, surface-layer proteins derived from lactobacilli, plant-derived small substances, milk-derived peptides, lactoferrin, lysozyme [9,32,35,[56][57][58][59][60].…”

Application of the Reuterin System as Food Preservative or Health-Promoting Agent: A Critical Review

“…Presently, there is no report on the resistance of pathogenic microorganisms to the reuterin system. Reuterin was considered to have a bactericidal effect on methicillin-resistant S. aureus [ 13 ]. Bennett et al [ 14 ] reported that reuterin was the most effective against multidrug-resistant bacteria causing bovine mastitis, compared with nisin, bactofein and pediocin.…”

“…The antimicrobial mechanism of the reuterin system remains unclear due to the complexity and dynamic nature of the system. Nevertheless, the reuterin system exhibits a broad-spectrum antimicrobial activity against pathogens and spoilage organisms, including Gram-positive and Gram-negative bacteria, yeasts, fungi, protozoa, viruses [ 12 ] and even antibiotic-resistant bacteria [ 13 , 14 ]. Gram-negative bacteria are usually more sensitive to the reuterin system than Gram-positive bacteria [ 15 , 16 , 17 ].…”