Multivariate analysis of adaptive response to ferulic acid and p ‐coumaric acid after physiological stresses in Cronobacter sakazakii

Abstract

Aim: The present study demonstrated the antimicrobial activity of ferulic acid and p-coumaric acid against unstressed and stressed (cold stressed, starved and desiccated) Cronobacter sakazakii in laboratory media (37°C) and reconstituted powdered infant formulation (PIF) with mild heat treatment (50°C). Methods and results: Five phenolics, namely, quercetin, rutin, caffeic acid, ferulic acid and p-coumaric acid, were tested for antimicrobial activities against five strains of C. sakazakii either unstressed or stressed. Strain specific higher resistance to ferulic acid and p-coumaric acid was observed after stress adaptation in laboratory media. The effect of cross protection was validated using reconstituted PIF as delivery vehicle of selected compounds. Both pcoumaric acid and ferulic acid showed inhibition of C. sakazakii in a dose and time dependent manner as revealed by their viable cell counts. Principal component analysis revealed that the desiccated cells were more sensitive to phenolics in reconstituted PIF. Conclusions: Only ferulic acid and p-coumaric acid showed marked antibacterial activity with minimum inhibitory concentration in the range of 2Á5-5 mg ml À1 for unstressed C. sakazakii cells in tryptone soy broth. The maximum inhibition was achieved with 20 mg ml À1 of both the tested polyphenols in reconstituted PIF. Cold stress and starvation stress did not impart any protection nor increased the susceptibility of C. sakazakii, whereas desiccation resulted in increased susceptibility to phenolic compounds. Significance and Impact of the Study: The results obtained in this study helps in understanding the effect of environmental stresses during processing on susceptibility of C. sakazakii to natural antimicrobial agents. Future transcriptomic studies and functional genetic studies are warranted to understand the strain specific stress responses for the development of better control methods possibly by using these natural antagonists.

Alkyl ferulic acid esters: Evaluating their structure and antibacterial properties

“…Plant antimicrobials were widely used for their safety, environment-friendly, no drug resistance, and low residue, among other advantages. Studies have revealed that some phenolic substances showed antibacterial activities, for example, they be inserted into the phospholipid layer of bacterial membranes, disrupting the van der Waals interaction between the fatty acyl chains and destroying the phospholipid bilayer and membrane integrity ( Burt, 2004 ; Chauhan et al, 2021 ; Li et al, 2021 ). As the ion gradient of the cell membrane is disrupted, important components such as ions and macromolecules are released from within the cell, resulting in the death of the bacteria.…”

Comparison of Origanum Essential Oil Chemical Compounds and Their Antibacterial Activity against Cronobacter sakazakii

“…Natural plant extracts, such as essential oils and organic acids, have a specific antibacterial effect [ 1 ]. Essential oil exerts a bacteriostatic effect on multiple targets in bacteria by disrupting the bacterial membrane and reducing the intracellular ATP concentration and intracellular pH value [ 2 , 3 ]; thus, developing antibiotic resistance is not easy.…”