title: Antimicrobial Activity of Ferulic Acid Against Cronobacter sakazakii and Possible Mechanism of Action.
abstract: Cronobacter sakazakii is an opportunistic pathogen transmitted by food that affects mainly newborns, infants, and immune-compromised adults. In this study, the antibacterial activity of ferulic acid was tested against C. sakazakii strains. Minimum inhibitory concentration of ferulic acid against C. sakazakii strains was determined using the agar dilution method. Changes in intracellular pH, membrane potential and intracellular ATP concentration were measured to elucidate the possible antibacterial mechanism. Moreover, SYTO 9 nucleic acid staining was used to assess the effect of ferulic acid on bacterial membrane integrity. Cell morphology changes were observed under a field emission scanning electron microscope. The minimum inhibitory concentrations of ferulic acid against C. sakazakii strains ranged from 2.5 to 5.0 mg/mL. Addition of ferulic acid exerted an immediate and sustained inhibition of C. sakazakii proliferation. Ferulic acid affected the membrane integrity of C. sakazakii, as evidenced by intracellular ATP concentration decrease. Moreover, reduction of intracellular pH and cell membrane hyperpolarization were detected in C. sakazakii after exposure to ferulic acid. Reduction of green fluorescence indicated the injury of cell membrane. Electronic microscopy confirmed that cell membrane of C. sakazakii was damaged by ferulic acid. Our results demonstrate that ferulic acid has moderate antimicrobial activity against C. sakazakii. It exerts its antimicrobial action partly through causing cell membrane dysfunction and changes in cellular morphology. Considering its antimicrobial properties, together with its well-known nutritional functions, ferulic acid has potential to be developed as a supplement in infant formula or other foods to control C. sakazakii.
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Chao
authors.initials: C
authors.lastname: Shi
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Miaochun
authors.initials: M
authors.lastname: Yang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Kaikuo
authors.initials: K
authors.lastname: Song
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Yifei
authors.initials: Y
authors.lastname: Chen
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Jia
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Rui
authors.initials: R
authors.lastname: Dong
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Lu
authors.initials: L
authors.lastname: Cui
authors.affiliation: College of Food Science and Engineering, Northwest A&F University , Yangling, Shaanxi, China .
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xia
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000378:metabolism* / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D049109:Cell Proliferation / Q000187:drug effects; D002681:China; D015169:Colony Count, Microbial; D003373:Coumaric Acids / Q000378:metabolism* / Q000494:pharmacology; D044083:Cronobacter sakazakii / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D019587:Dietary Supplements; D024881:Drug Resistance, Bacterial; D005520:Food Preservatives / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007223:Infant; D007225:Infant Food / Q000382:microbiology; D041943:Infant Formula / Q000382:microbiology; D007424:Intracellular Fluid / Q000187:drug effects / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008855:Microscopy, Electron, Scanning; D013045:Species Specificity
chemical_list: D000900:Anti-Bacterial Agents; D003373:Coumaric Acids; D005520:Food Preservatives; D000255:Adenosine Triphosphate; C004999:ferulic acid