Screening of Anti-Biofilm Compounds from Marine-Derived Fungi and the Effects of Secalonic Acid D on Staphylococcus aureus Biofilm

Abstract

Biofilm formation of Staphylococcus aureus is one of its mechanisms of drug resistance. Antibiofilm screening of 106 compounds from marine-derived fungi displayed that 12 compounds inhibited S. aureus biofilm formation by >50% at the concentration of 100 µg/ml, and only secalonic acid D (SAD) and B inhibited by >90% at 6.25 µg/ml without inhibiting cell growth after 24-h incubation. Meanwhile, it was found that the double bond between C-1 and C-10 of citrinin derivatives and the CC connection position of two chromone monomers may be important for their anti-biofilm activities. Moreover, SAD slightly facilitated biofilm eradication and influenced its architecture. Furthermore, SAD slowed the cell growth rate in the preceding 18-h incubation and differentially regulated transcriptional expression of several genes, such as agr, isaA, icaA, and icaD, associated with biofilm formation in planktonic and biofilm cells, which may be the reason for the anti-biofilm activity of SAD. Finally, SAD acted synergistically against S. aureus growth and biofilm formation with other antibiotics. These findings indicated that various natural products from marine-derived fungi, such as SAD, could be used as a potential biofilm inhibitor against S. aureus.

Phialomyces macrosporus: Chemical Constituents, Antimicrobial Activity and Complete NMR Assignments for the 7,7′‐Biphyscion

“…Compounds 2 and 3 were assayed for their antimicrobial activities, in which only compound 3 (secalonic acid D) displayed marked growth inhibition at concentrations of 15.6 μg/mL for Staphylococcus aureus and Salmonella choleraesius ) and 0.97 μg/mL for Bacillus subtilis (positive control chloramphenicol exhibited MIC values of 0.97, 15.6 and 0.48 μg/mL, respectively). These results demonstrate a significant antimicrobial activity of compound 3 reinforcing the reports observed in other studies . However, this compound is most notably recognized because of its cytotoxicity, teratogenicity and mutagenicity …”

“…These results demonstrate a significant antimicrobial activity of compound 3 reinforcing the reports observed in other studies. [35,36] However, this compound is most notably recognized because of its cytotoxicity, teratogenicity and mutagenicity. [37 -40] Since the fungus P. macrosporus is being studied as a promising biocontrol agent in plants of agricultural interest, [15,41] our results suggest that it will be necessary to review this purpose since we detect that this fungus produces a compound with harmful activities and, therefore, its use must be such that it does not cause any risk to the society.…”

The Evaluation of Antimicrobial and Antibiofilm Activity of Bioactive Compounds Obtained from Aspergillus Sclerotiorum

“…But there must be different methods for purification at the higher concentrations of the densest band to achieve more effective results and to keep the work going. Similarly, Wang et al (2017) reported that 18 components obtained from marine-derived fungi showed S. aureus growth at a concentration of 100 μg ml -1 and an antibiofilm activity of 50% on biofilm formation.…”

PYED-1 Inhibits Biofilm Formation and Disrupts the Preformed Biofilm of Staphylococcus aureus

“…In contrast, the transcriptional levels of isaA were increased by PYED-1 in planktonic cells [11]. Changes in the transcriptional control of isaA in planktonic cells and preformed biofilms were also observed when treating planktonic and biofilm cells with secalonic acid D [31].…”