In Vitro Antibacterial Activity and Synergistic Antibiotic Effects of Phlorotannins Isolated from Eisenia bicyclis Against Methicillin‐Resistant Staphylococcus aureus

Abstract

Six phlorotannins, isolated from Eisenia bicyclis, were evaluated for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MIC) of the compounds were in the range 32 to 64 µg/mL. Phlorofucofuroeckol-A (PFF) exhibited the highest anti-MRSA activity, with an MIC of 32 µg/mL. An investigation of the interaction between these compounds and the β-lactam antibiotics ampicillin, penicillin, and oxacillin revealed synergistic action against MRSA in combination with compound PFF. To our knowledge, this is the first report on the anti-MRSA activity of phlorotannins from E. bicyclis. The results obtained in this study suggest that the compounds derived from E. bicyclis can be a good source of natural antibacterial agents against MRSA.

Algae Polyphenolic Compounds and Modern Antibacterial Strategies: Current Achievements and Immediate Prospects

“…MRSA first appeared in the late 1970s [ 65 ]. The widespread use of methicillin, having resistance to penicillinase, has led to the emergence of this variant of S. aureus [ 66 ], which also exhibits multidrug resistance [ 67 ].…”

“…Thus, S.H. Eom et al [ 66 ] isolated six phlorotannins from an extract of the brown alga E. bicyclis and tested the sensitivity of MRSA to them. The MIC of the compounds ranges from 32 to 64 μg/mL.…”

“…Earlier, six compounds are isolated from an ethyl acetate extract, among which PFF-A is the most active against MRSA. The MIC of PFF-A against MRSA is 32 μg/mL [ 66 ].…”

“…The intracellular contents are extruded. In control, cells, on the contrary, have normal morphology and are viable [ 66 , 72 ].…”

“…Thus, the results of studies by scientists from different countries allow us to hope that PF of seaweed can be used to create drugs against antibiotic-resistant bacteria, including S. aureus , which currently claims thousands of lives in all regions of the world [ 66 , 73 ]. Understanding the genomic mechanisms of action of pharmacologically active metabolites, new possibilities for their preparation and purification, as well as more advanced methods for determining the structure of compounds should open up new possibilities for the practical use of these most interesting and promising biopolymers.…”