Advisor(s)
Abstract(s)
Several studies have explored the antimicrobial properties of manuka honey (MkH).
However, the data available regarding antibacterial action mechanisms are scarcer. The aim of
this study was to scrutinize and characterize primary e ects of manuka honey (MkH) upon the
physiological status of Staphylococcus aureus and Escherichia coli (as Gram-positive and Gram-negative
bacteria models, respectively), using flow cytometry (FC) to reveal its antibacterial action mechanisms.
E ects of MkH 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 carried out
under the same conditions. Additionally, MkH e ect on e ux pumps was also studied in an E. coli
strain with an over-expression of several e ux pumps. Exposure of bacteria to MkH resulted in
physiological changes related to membrane potential and membrane integrity; these e ects displayed
slight di erences among bacteria. MkH induced a remarkable metabolic disruption as primary
physiological effect upon S. aureus and was able to block effux pump activity in a dose-dependent
fashion in the E. coli strain.
Description
Keywords
Antibacterial effects Bacteria models Efflux pump Flow cytometry Manuka honey Metabolic activity
Pedagogical Context
Citation
Combarros-Fuertes, Patricia; Estevinho, Leticia M.; Teixeira-Santos, Rita; Rodrigues, Acácio G.; Pina-Vaz, Cidália; Fresno, Jose M.; Tornadijo, M. Eugenia (2019). Evaluation of physiological effects induced by manuka honey upon staphylococcus aureus and escherichia coli. Microorganisms. ISSN 2076-2607. 7, p. 1-13