Bisdemethoxycurcumin Reduces Methicillin-Resistant Staphylococcus aureus Expression of Virulence-Related Exoproteins and Inhibits the Biofilm Formation

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen of nosocomial infection, which is resistant to most antibiotics. Presently, anti-virulence therapy and anti-biofilm therapy are considered to be promising alternatives. In the current work, we investigated the influence of bisdemethoxycurcumin (BDMC) on the virulence-related exoproteins and the biofilm formation using a reference strain and clinic isolated strains. Western blotting, quantitative RT-PCR, and tumor necrosis factor (TNF) release assay were performed to assess the efficacy of BDMC in reducing the expression of Staphylococcus enterotoxin-related exoproteins (enterotoxin A, enterotoxin B) and α-toxin in MRSA. The anti-biofilm activity of BDMC was evaluated through a biofilm inhibition assay. The study suggests that sub-inhibitory concentrations of BDMC significantly inhibited the expression of sea, seb, and hla at the mRNA level in MRSA. Moreover, the expression of virulence-related exoproteins was significantly decreased by down-regulating accessory gene regulator agr, and the inhibition of biofilms formation was demonstrated by BDMC at sub-inhibitory concentrations. Consequently, the study suggests that BDMC may be a potential natural antibacterial agent to release the pressure brought by antibiotic resistance.

Antibiofilm Activity of a Curcuma zedoaria Rosc Rhizome Extract against Methicillin-Resistant and Susceptible Staphylococcus aureus

“…Newton Suwal et [38]. Moreover, demethoxycurcumin, a major constituent of curcuminoids found in this study, has also been reported for antibiofilm activity in Candida albicans [39], while bisdemethoxycurcumin reduced biofilm formation in MRSA [40]. Factually, the adhesion of the bacterial cell to abiotic or biotic surfaces is the initial step in biofilm formation.…”

Antimicrobial effect of pimozide by targeting ROS‐mediated killing in Staphylococcus aureus

“…Anti‐virulence property of PMZ was tested by reducing the production level of the important toxin HLA (α‐hemolysin) by the ELISA method according to 35 with some modifications. Briefly, overnight‐grown cultures of S. aureus were re‐cultured in TSB at 37°C until the mid‐log phase.…”