Evaluation of antimicrobial and antibiofilm properties of proanthocyanidins from Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves against Staphylococcus epidermidis

Abstract

Staphylococcus epidermidis has emerged in recent years as one of the most important opportunistic pathogens owing to its ability to attach to processing surfaces in the food industry. Demands of foodstuffs maintaining microbiological safety and stability enhance the need to develop natural antimicrobial agents as food preservatives. Proanthocyanidins from Chinese bayberry leaves (BLPs) belonging to the class of polyphenols promise to be a potential antibacterial material against bacterial adhesion and biofilm formation. The aim of the present study was to investigate the effects of BLPs on S. epidermidis growth and biofilm formation. BLPs possessed antimicrobial activity with MIC and MBC of 320 and 640 μg/ml, respectively. Scanning electron microscopy, transmission electron microscopy, and flow cytometry analysis revealed a loss of the cell structure and function after treatment of BLPs, evidenced by cell membrane hyperpolarization and changes in cellular morphology. BLPs inhibited the biofilm formation by S. epidermidis on polystyrene microplates. Atomic force microscopy analysis showed that BLPs could decrease the stiffness and adhesion force of the cell envelope, which might account for the inhibition of biofilm formation. In summary, this study indicated that BLPs have potential to be developed as natural preservatives to control S. epidermidis in foods.

Simultaneous determination of the mechanical properties and turgor of a single bacterial cell using atomic force microscopy

“…Atomic force microscopy (AFM) techniques have been shown to be an effective approach to measure the mechanical properties of bacterial cells. 3,13,[23][24][25][26][27][28][29][30] The Young's modulus of various bacterial cells measured by AFM nanoindentation were in the range of 0.05-769 MPa depending on the type of bacterium, environmental conditions, and theoretical models. 8 For example, Eaton et al 31 measured a higher elastic modulus for the rod-shaped model bacterium Escherichia coli than for the spherical bacterium Staphylococcus aureus using AFM in airdried conditions, which may be caused by different cell wall architectures and geometry effects on the applicability of the Hertz contact model using a pyramidal probe.…”

Antibacterial Activity of Plant Polyphenols

“…The antimicrobial activity of lavandula against Staphylococcus epidermidis was described in detail by Zou et al [22]. The antimicrobial activity of the lavandula phenolic extract was reported by a Moroccan research team [23].…”

Ressourcenschonende Synthesen im Zeitalter der Nachhaltigkeit am Beispiel der Procyanidine

“…In Deutschland werden täglich 144 mg über die Nahrung aufgenommen. [8] Proanthocyanidinen werden zahlreiche positive physiologische Wirkungen zugeschrieben, darunter antioxidative [9], blutdrucksenkende [10], entzündungshemmende [10], antidiabetische [11], anti-mutagene [12] sowie antimikrobielle Effekte [13]. Systematische Untersuchungen zur Struktur-Wirkungsbeziehung von Proanthocyanidinen sind aufgrund fehlender Referenzsubstanzen bisher kaum durchgeführt wurden.…”