Efficacy of Trans-cinnamaldehyde and Eugenol in Reducing Acinetobacter baumannii Adhesion to and Invasion of Human Keratinocytes and Controlling Wound Infection In Vitro.

ABSTRACT

The study investigated the efficacy of two natural, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC), and eugenol (EG) for decreasing Acinetobacter baumannii adhesion to and invasion of human keratinocytes (HEK001). Moreover, the efficacy of two PDAs for inhibiting A. baumannii biofilm formation was determined using an in vitro collagen matrix wound model. Additionally, the effect of TC and EG on A. baumannii biofilm architecture was visualized using confocal scanning microscopy. Further the effect of both PDAs on genes critical for biofilm synthesis was determined using real-time quantitative polymerase chain reaction. Both TC and EG significantly reduced A. baumannii adhesion and invasion to HEK001 by ~2 to 3 log10 CFU/mL (p < 0.05) compared with the controls (p < 0.05). Further, after 24 and 48 h, TC and EG inhibited biofilm formation by ~1.5 to 2 and ~2 to 3.5 log10 CFU/mL, compared with controls (p < 0.05). Confocal microscopy revealed that TC and EG disrupted the biofilm architecture. RT-qPCR results indicated that two phytochemicals significantly down-regulated the transcription of genes associated with A. baumannii biofilm production. The results suggest that both TC and EG could potentially be used to treat A. baumannii wound infections; however, their efficacy in in vivo models needs to be validated. Copyright © 2016 John Wiley & Sons, Ltd.