The mechanism of antibacterial activity of phlorofucofuroeckol-A against methicillin-resistant Staphylococcus aureus

Abstract

To find more effective ways of overcoming methicillin-resistant Staphylococcus aureus (MRSA), there has been considerable interest in the use of marine-derived constituents as alternatives to control pathogenic microorganisms. In this study, we investigated whether phlorofucofuroeckol-A (PFF) isolated from the edible brown alga Eisenia bicyclis suppressed production or function of penicillin-binding protein 2a (PBP2a). The antimicrobial mode of action of PFF in MRSA was identified by measuring cell membrane integrity and using the time-kill curve method. We attempted to determine the antimicrobial effects of PFF on the expression level of the resistance determinants mecA and its regulatory genes mecI and mecR1 in MRSA by reverse transcriptase polymerase chain reaction. PFF suppressed mecI, mecR1, and mecA gene expression in a dose-dependent manner. In addition, we revealed PFF mediates the suppressive effect of PBP2a expression in MRSA by Western blot analysis. PFF suppressed production of the PBP2a protein, suggesting that PFF probably acts by controlling the methicillin resistance-associated genes involved in the cell wall and production of PBP2a. These results demonstrate that PFF isolated from E. bicyclis significantly suppressed the expression of the methicillin resistance-associated genes and production of PBP2a, which is considered the primary cause of methicillin resistance.

Secondary Bacterial Infections Associated with Influenza Pandemics

“…Necrotising pneumonia is highly associated with either the presence of Panton-Valentine leukocidin (PVL) or prior/co influenza infection (DeLeo and Musser, 2010). MRSA is a particularly problematic pathogen and concern for public health as it can be hard to treat due to its multidrug-resistant properties (Wu et al, 2005; Eom et al, 2014; Fishovitz et al, 2014). …”

Phlorotannins

“…The phenolic group of phlorotannins can bind with the amino group of bacterial proteins (Wang et al, 2009). Eom et al (2012Eom et al ( , 2013Eom et al ( , 2014 reported the effective ways to overcome methicillin-resistant Staphylococcus aureus growth by phlorofucofuroeckol-A, which is derived from E. bicyclics marine algae. The phlorotannins suppressed mecI, mecR1,and mecA gene expression in a dose-dependent manner .…”

Synergistic Antibacterial Activity of Ecklonia cava (Phaeophyceae: Laminariales) against Listeria monocytogenes (Bacillales: Listeriaceae)

“…The contents of total phenolic (TP) compounds in the fractionated E. cava extracts were evaluated using the modified Folin-Ciocalteu method (Eom et al, 2013), taking phloroglucinol as a standard and with results expressed as phloroglucinol equivalents (PGE). The concentration of TP compounds was 241.0 ± 1.6 mg PEG/g in the MeOH extract, 26.8 ± 6.9 mg PEG/g in the hexane fraction, 83.3 ± 1.0 mg PEG/g in the DCM fraction, 556.8 ± 2.7 mg PEG/g in the EtOAc fraction, 416.3 ± 18.4 mg PEG/g in the BuOH fraction, and 34.3 ± 4.1 mg PEG/g in the water fraction.…”