Susceptibility of Escherichia coli O157 to chitosan‐arginine in beef liquid purge is affected by bacterial cell growth phase

Abstract

Summary Here, we evaluated the impact of bacterial growth stage on the effect of chitosan‐arginine (Ch‐arg) on Escherichia coli O157:H7 cell numbers and metabolic activity within contaminated beef juice held at room temperature. Using a lux‐marked metabolic reporter strain of E. coli O157:H7, the results showed that Ch‐arg was most bioactive against cells in the lag phase and exponential phase. In comparison, there was a reduced, although still significant, inhibitory effect of Ch‐arg on the viability and metabolic activity of E. coli O157 held in stationary phase. Ch‐arg reduced, but did not eliminate E. coli O157 growth in the meat juice over 48 h. Based on the evidence presented here and elsewhere, we conclude that Ch‐arg can limit the growth and activity of food spoilage bacteria; however, it cannot completely eliminate bacterial contaminants originally present. Ch‐arg should therefore be viewed as a potentially protective measure rather than a biocidal agent that completely eliminates the risk of pathogen transfer in the food chain.

Antimicrobial Chitosan and Chitosan Derivatives: A Review of the Structure–Activity Relationship

“…Chitosan has been conjugated to several cationic amino acids as well as peptides (Figure ). The synthesis of chitosan–arginine and chitosan–guanidine conjugates has been observed in many studies. , The carboxyl group of arginine was first activated by NHS/EDC at a first molar ratio and then coupled to the amino group of chitosan during different reaction times. This resulted in chitosan–arginine derivatives having DS in the range 0.08–0.28 .…”

Natural Preservatives for Extending the Shelf‐Life of Seafood: A Revisit

“…The disagreement in antimicrobial properties is attributed to the differences in the degree of deacetylation and a molecular weight between chitosan and chitooligosaccharide (No et al., ; No, Young Park, Ho Lee, & Meyers, ; Tsai et al., ). Other influencing factors include the initial microbial load, pH, concentration and type of biopolymer, temperature, and nature of the food (Alishahi & Aïder, ; Ganguly, ; Kumirska et al., ; Lahmer, Jones, Townsend, Baker, & Williams, ).…”

Metal–organic framework in anl-arginine copper(ii) ion polymer: structure, properties, theoretical studies and microbiological activity

“…It was demonstrated that antibiotics administrated with L-Arg showed 10 to 100 fold greater activity in biolm reduction than antibiotics administrated alone, which may be associated with the ability of L-arginine to increase the metabolic rate of the bacteria remaining in the lower levels of biolm, especially in anoxic conditions. 44 Another study 45,46 also demonstrated the L-Arg antimicrobial properties realized through affecting their metabolic pathways. chitosan-arginine (Ch-Arg) complexes reduce E. coli O157 growth in lag or exponential phase.…”

“…chitosan-arginine (Ch-Arg) complexes reduce E. coli O157 growth in lag or exponential phase. 45 Chitosan is a carbohydrate extracted from shellsh commonly used as an antimicrobial agent and food preservative. Chemical derivatives of chitosan with positively charged L-arginine may increase the surface charge density, thus, the Ch-Arg complex reveals greater antimicrobial effect against Gram-negative bacteria than unmodied chitosan.…”