Author(s): Combarros-Fuertes, Patricia ; Estevinho, Leticia M. ; Teixeira-Santos, Rita ; Rodrigues, Acácio G. ; Pina-Vaz, Cidália ; Fresno, José María ; Tornadijo, María Eugenia
Date: 2020
Persistent ID: http://hdl.handle.net/10198/22323
Origin: Biblioteca Digital do IPB
Subject(s): Antibacterial mechanisms; Avocado honey; Chestnut honey; Escherichia coli; Flow cytometry; Polyfloral honey; Staphylococcus aureus
Numerous studies have explored the antibacterial properties of di erent types of honey from all around the world. However, the data available describing how honey acts against bacteria are few. The aim of this study was to apply a flow cytometry (FC) protocol to examine and characterize the primary e ects of three varieties of honey (avocado, chestnut and polyfloral) upon physiological status of Staphylococcus aureus and Escherichia coli cells to reveal their antibacterial action mechanisms. The e ects of honey samples on membrane potential, membrane integrity, and metabolic activity were assessed using di erent fluorochromes, in a 180 min time course assay. Time-kill experiments were also carried out under similar conditions. Exposure of S. aureus and E. coli to the distinct honey samples resulted in physiological changes related to membrane polarization and membrane integrity. Moreover, honey induced a remarkable metabolic disruption as primary physiological e ect upon S. aureus. The di erent honey samples induced quite similar e ects on both bacteria. However, the depth of bacteria response throughout the treatment varied depending on the concentration tested and among honey varieties, probably due to compositional di erences in the honey.
