Synthetic bromated furanone inhibits autoinducer‐2‐mediated communication and biofilm formation in oral streptococci

Abstract

We suggest that the effect is linked to interference with the AI-2 signaling pathway because adding furanone to the medium had no effect on the ability of the AI-2-defective S. anginosus luxS and S. intermedius luxS mutants to form biofilms.

Inhibition ofSteptococcus mutansbiofilm formation by extracts ofTenacibaculumsp. 20J, a bacterium with wide-spectrum quorum quenching activity

“…To exclude that 20J-PCE affects bioluminescence in V. harveyi through factors nondependent on QS, the mutant V. harveyi JAF548 [31] in which bioluminescence is expressed independently of QS control was used. Moreover, the Furanone C30, which was suggested to prevent biofilm formation in S. mutans previously [22,23], and extracts obtained from the closely related species T. maritimum NCBI2154 T , a strain with no AHL-lactonase activity [36], were also tested. Results showed that after 8 h, the 20J extract completely eliminates light production by the reporters BB170 and JMH597 compared to control wells (Figure 1(a)).…”

“…Furanone has been reported as a QS inhibitor that affects biofilm formation in S. mutans using the safranine staining and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assays as quantification methods [22,23], although the active concentrations (0.15–4 μg ml −1 ) were significantly higher than those assayed in the present study (0.02 μg ml −1 ) and close to the toxicity threshold for this molecule that has been established at concentrations ≥1 µM (0.2 μg ml −1 ) [44]. He et al [23] indicate that the furanone acts through an unknown mechanism not dependent of the production of the QS-signal AI-2 since it affected not only S. mutans but also the luxS mutant strain.…”

“…However, the structure of the AI-2 produced by streptococci is unknown [22], more studies being needed to understand the interference of 20J extracts and other inhibitors with the AI-2 QS system in this species. Although additional experiments using mixed species models would be required in order to evaluate the potential of 20J extracts to prevent dental plaque formation and to control the progress of oral chronic infections such as periodontitis, the inhibition of the biofilm formation observed in another two oral streptococci, S. oralis and S. dentisani , indicates a wide spectrum activity.…”

“…Furanones, which are known to inhibit communication based on acyl homoserine lactone (AHL) and AI-2 signals [21], have been reported to affect biofilm formation in S. mutans . A previous study indicated that the biofilm inhibition observed in S. mutans supplemented with the furanone C52 is linked with the interference with AI-2-controlled processes [22]. However, another study reported the inhibition of biofilm formation in S. mutans by the synthetic furanone C30 through an unknown mechanism not dependent of QS-signal AI-2, since the luxS mutant was also affected [23].…”

StreptococcusAdherence and Colonization

“…Bromofuranone interferes with AI-2 signaling pathways and inhibits the formation of single-species biofilms of S. mutans and S. intermedius (361). However, halogenated furanones show toxic side effects on human cells and possible carcinogenic properties that make them unsuitable for use as pharmaceuticals for humans (56).…”