Antimicrobial, antiadhesive and antibiofilm activity of an ethanolic, anthocyanin-rich blueberry extract purified by solid phase extraction

• DOI: 10.1111/jam.13215
• Publication Date: 2016-06-28T12:27:22Z
• Authors: S. Silva; E.M. Costa; M. Mendes; R.M. Morais; C. Calhau; M.M. Pintado
• Keywords: 0303 health sciences; Bacteria; Plant Extracts; Blueberry Plants; Solid Phase Extraction; Microbial Sensitivity Tests; Antimicrobial activity; Vaccinium corymbosum; Bacterial Physiological Phenomena; Blueberry; Bacterial Adhesion; Anti-Bacterial Agents; 3. Good health; Anthocyanins; Kinetics; 03 medical and health sciences; Antibiofilm activity; Biofilms; Adhesion inhibition

The present work aimed to characterize the impact of an anthocyanin-rich blueberry extract upon the growth, adhesion and biofilm formation of several pathogens including some multiresistant bacteria.A group comprised of reference strains and clinical multiresistant isolates of Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis, Acinetobacter baumannii and Staphylococcus aureus, were used to screen for antimicrobial activity. Microbial growth was determined through the measurement of the optical density while adhesion and biofilm formation was determined using the standard crystal violet staining procedure. The results showed that, while blueberry extract was only effective in hindering the growth of Staph. aureus and E. coli, it was capable of significantly inhibiting biofilm formation and bacterial adhesion for all micro-organisms tested.The extract demonstrated a considerable potential as a natural, alternative antimicrobial capable of either interfering with microbial growth or hamper the adhesion to surfaces, with Staph. aureus proving to be the most susceptible micro-organism.The overall study demonstrates the potential of anthocyanin extracts as natural effective alternative antimicrobial agents. Additionally, the extract's capacity to reduce adhesion without reducing bacterial growth reduces the likeliness of resistance development while reducing the probability of infection.