Newly-synthesized chalcones-inhibition of adherence and biofilm formation of methicillin-resistant Staphylococcus aureus

Abstract

Biofilm formation and adherence of bacteria to host tissue are one of the most important virulence factors of methicillin-resistant strains of Staphylococcus aureus (MRSA). The number of resistant strains is seriously increasing during the past years and bacteria have become resistant, not only to methicillin, but also to other commonly used antistaphylococcal antibiotics. There is a great need for discovering a novel antimicrobial agent for the treatment of staphylococcal infections. One of the most promising groups of compounds appears to be chalcones. In present study we evaluated the in vitro effect of three newly synthesized chalcones: 1,3- Bis-(2-hydroxy-phenyl)-propenone, 3-(3-Hydroxy-phenyl)-1-(2-hydroxy-phenyl)-propenone and 3-(4-Hydroxy-phenyl)-1-(2-hydroxy-phenyl)-propenone on glycocalyx production, biofilm formation and adherence to human fibronectin of clinical isolates and laboratory control strain of MRSA (ATCC 43300). Subinhibitory concentrations of the tested compounds reduced the production of glycocalyx, biofilm formation and adherence to human fibronectin of all MRSA strains. Inhibition of biofilm formation was dose dependent and the most effective was 1,3- Bis-(2-hydroxy-phenyl)-propenone. In our study we demonstrated that three newly-synthesized chalcones exhibited significant effect on adherence and biofilm formation of MRSA strains. Chalcones may be considered as promising new antimicrobial agents that can be used for prevention of staphylococcal infections or as adjunct to antibiotics in conventional therapy.

Antibacterial activity of flavonoids and their structure–activity relationship: An update review

“…pylori urease indicated that 4′,7,8‐trihydroxy‐isoflavene ( 141 ) was the most active compound with IC 50 0.85 mM, which was 20‐fold more potent than standard urease inhibitor (acetohydroxamic acid; Xiao et al, ). Bozic, Milenkovic, Ivkovic, and Cirkovic () reported that among three newly synthesized chalcones with OH at positions 2, 3, and 4 of B ring of 1,3‐bis‐(2‐hydroxy‐phenyl) ( 145 ; with hydroxy group in position 2) exhibited significant effect on adherence and biofilm formation of MRSA strains. In the synthetic fluoroquinolone‐flavonoid hybrids, naringenin‐ethylidene‐ciprofloxacin ( 146 ; with cyclopropan on the N atom) was the most active compound and showed eightfold to 88‐fold more potent activity than the standard drug ciprofloxacin against E .…”

Licheniocin 50.2 and Bacteriocins from Lactococcus lactis subsp. lactis biovar. diacetylactis BGBU1-4 Inhibit Biofilms of Coagulase Negative Staphylococci and Listeria monocytogenes Clinical Isolates

“…Hence, the prevention of biofilms is of utmost importance for modern medicine. The fact is that subinhibitory concentration of various antimicrobial agents possesses inhibitory effects on biofilm formation by different microorganisms [30,31]. On the other hand, it has also been reported that subinhibitory concentrations of some antimicrobial agents even enhance biofilm formation, for example erythromycin, nafcillin, quinupristin-dalfopristin, tetracycline and vancomycin on staphylococcal biofilm formation [32].…”

Modulation of Biofilm Growth by Sub‐Inhibitory Amounts of Antibacterial Substances

“…The effects of sub-MICs of three newly synthesized chalcones on methicillin-resistant S. aureus were examined. Both biofilm formation and adherence to human fibronectin were reduced, as well as the release of EPS [87].…”