Proteomic analysis of the mode of antibacterial action of trans-cinnamaldehyde against Cronobacter sakazakii 415.

Cronobacter sakazakii is an opportunistic foodborne pathogen that contaminates powdered infant formula, causing a rare but life-threatening infection in neonates and infants. Contaminated powdered infant formula represents the only known source of infection in infants. We previously reported that trans-cinnamaldehyde (TC), an ingredient in cinnamon, inactivated C. sakazakii in powdered infant formula. Although the antimicrobial properties of TC have been well established, only limited information is available on its antimicrobial mechanisms, especially at the molecular level. Therefore, we performed a proteomic analysis of the outer membrane and whole cell proteins from TC-treated C. sakazakii to investigate its potential antimicrobial mechanisms against C. sakazakii. The proteomic data revealed that TC exerts antimicrobial effects by several mechanisms, including disruption of carbohydrate, amino acid, and lipid metabolism. Additionally, TC compromises motility, attachment, and invasion ability and cellular defenses of C. sakazakii against oxidative stress, thereby reducing its virulence. The results of this study suggest that TC could be potentially used for controlling C. sakazakii.