Antimicrobial Activity of ɛ‐Polylysine against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in Various Food Extracts

Abstract

This study compared the antimicrobial effects of epsilon-polylysine (epsilon-PL) against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes in 6 food extracts and in broth. The food extracts (10% (w/w) in distilled water) evaluated were fat-free and whole fat milk, beef, bologna, rice, and vegetables (50:50 ratio of broccoli and cauliflower). epsilon-PL was tested at 0.005% and 0.02% (w/v) against E. coli O157:H7 and L. monocytogenes, and 0.02% and 0.04% (w/v) against S. Typhimurium. The substrates were inoculated (5 log CFU/mL) and periodically analyzed for surviving populations during storage at 12 degrees C for 6 d. In general, all 3 pathogens reached 7 to 9 log CFU/mL within 2 d in control substrates (no epsilon-PL). Immediate bactericidal effects (P < 0.05) following exposure to epsilon-PL were obtained in the rice (all pathogens) and vegetable (E. coli O157:H7 and S. Typhimurium) extracts. During storage, antimicrobial effects of epsilon-PL were more pronounced in the food extracts than in the broth medium. The greatest antimicrobial activity for all 3 pathogens was obtained in the rice and vegetable extracts, where counts were reduced (P < 0.05) to below the detection limit (0.0 log CFU/mL) by one or both epsilon-PL concentrations tested. In the other food extracts (fat-free milk, whole fat milk, beef, and bologna), both epsilon-PL concentrations tested generally resulted in lower (P < 0.05) pathogen levels at the end of storage compared to initial counts, with better bactericidal effects exerted by the higher of the 2 epsilon-PL concentrations. Additional research is needed to explore the potential antimicrobial effects of epsilon-PL in real food systems.

Food-grade cationic antimicrobial ε-polylysine transiently alters the gut microbial community and predicted metagenome function in CD-1 mice

“…[29][30][31] Thus, we hypothesized that ε-polylysine modulates specific gut microbial populations and the overall community structure during this dietary intervention. Interestingly, the microbial community adapted or compensated for ε-polylysine activity and converged on the initial equilibrium state by the final sampling.…”

“…In addition, ε-polylysine restricts a broad range of Grampositive and Gram-negative bacterial taxa, such as Bacillus coagulans, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium. [29][30][31] The antimicrobial activity of ε-polylysine has been largely attributed to its cationic charge, as this allows it to adsorb onto negatively charged microbial surfaces and disrupt the cell envelope. 32 The cationic nature of ε-polylysine often limits its application in foods as it could interact with anionic mucins in the mouth, or spontaneously complex with negatively charged molecules to impact food integrity.…”

Efficacy of ε-Polylysine, Lauric Arginate, or Acidic Calcium Sulfate Applied Sequentially for Salmonella Reduction on Membrane Filters and Chicken Carcasses

“…The effectiveness of ACS as a surface decontamination agent for reducing pathogens on beef or poultry carcasses or RTE meat products has been reported in several studies (3, 8, 10-12, 17, 25, 42). Another antimicrobial, 8-polylysine (EPL), is a cationic homopolymer of 25 to 35 L-lysine residues connected at the £-amino and a-carboxyl group juncture (6). EPL is an edible, water-soluble agent with a wide range of antimicrobial activity that includes both gram-positive and gram-negative bacteria (5,6,40,41).…”

Cationic polypeptides in a concept of oppositely charged polypeptides as prevention of postsurgical intraabdominal adhesions

“…Polypeptides are a group of macromolecules that are widely used today in biological research as drug carriers and gene vectors and for their antimicrobial properties [22][23][24][25][26][27]. They are water soluble, biodegradable and often described as non-toxic for humans and the environment [28].…”