Unusual Multiple Production of N-Acylhomoserine Lactones a by Burkholderia sp. Strain C10B Isolated from Dentine Caries

Abstract

Bacteria realize the ability to communicate by production of quorum sensing (QS) molecules called autoinducers, which regulate the physiological activities in their ecological niches. The oral cavity could be a potential area for the presence of QS bacteria. In this study, we report the isolation of a QS bacterial isolate C10B from dentine caries. Preliminary screening using Chromobacterium violaceum CV026 biosensor showed that isolate C10B was able to produce N-acylhomoserine lactones (AHLs). This bacterium was further identified as a member of Burkholderia, an opportunistic pathogen. The isolated Burkholderia sp. was confirmed to produce N-hexanoyl-L-homoserine lactone (C6-HSL), N-octanoyl-L-homoserine lactone (C8-HSL), N-decanoyl-L-homoserine lactone (C10-HSL) and N-dodecanoyl-L-homoserine lactone (C12-HSL).

Short-Chain N -Acylhomoserine Lactone Quorum-Sensing Molecules Promote Periodontal Pathogens in In Vitro Oral Biofilms

“…It is well known that while the cognate AHLs can activate the QS circuits, noncognate AHLs, even of a very similar structure, may act to inhibit the same receptor (43,44). The signaling molecules C 6 -HSL, C 8 -HSL, C 10 -HSL, and C 16 -HSL, which generated the most important changes in the model biofilms, have been previously described in bacteria isolated from the oral environment (23)(24)(25)(26). In contrast, other signals such as OC 6 -HSL, C 18 -HSL, and OC 18 -HSL, which showed the highest effect on the studied phenotypes, have not been described in the oral environment so far.…”

“…Despite the widespread ability among Gram-negatives to produce AHLs, attempts to establish production of these QS signals by oral bacteria using different bacterial reporter strains have remained unsuccessful (10,20,21). AHL-producing bacteria have been isolated from the oral cavity (22)(23)(24)(25)(26), although these isolates are not considered members of the core oral microbiome. Additionally, AHLs seem to influence growth and protein expression in P. gingivalis (27,28).…”

Acyl homoserine lactone-mediated quorum sensing in the oral cavity: a paradigm revisited

“…The current accepted paradigm does not assign a significant role to AHLs in dental plaque formation since these signals are almost completely excluded from the literature reviews on QS mechanisms in oral biofilms [13][14][15][16] . Although a few strains with the ability to produce AHLs were isolated from the human tongue surface and dental plaque samples [21][22][23][24][25] , the fact that AHLs could not be detected in pure cultures of pathogenic oral bacteria in previous studies [10][11][12] is the reason why a minor role is attributed to these signals in the oral cavity. The low sensitivity of the biosensors may be partially responsible for the low number of AHL-producing strains isolated from the oral cavity.…”

“…Additionally, several AHL-producing strains of Enterobacter sp., Klebsiella pneumoniae, Pseudomonas putida, Citrobacter amalonaticus (Levinea amalonaticus) L8A and Burkholderia sp. have been isolated from the human tongue surface and dental plaque samples [21][22][23][24][25] . Furthermore, a homologue of the AHL-synthase HdtS, as well as a LuxR-type receptor homologue, were identified in P. gingivalis W83 and P. gingivalis ATCC33277, respectively [26][27][28] .…”

Isolation of Marine Paracoccus sp. Ss63 from the Sponge Sarcotragus sp. and Characterization of its Quorum‐Sensing Chemical‐Signaling Molecules by LC‐MS/MS Analysis

“…The latter belong to different categories, including, among others: acylated homoserine lactones (AHLs), used by Gram‐negative bacteria (sometimes referred to as autoinducer‐1 [AI‐1]);1 oligopeptide‐based signals, used by Gram‐positive bacteria;2 and a shared furanone‐based system (autoinducer‐2, AI‐2), used by both Gram‐negative and Gram‐positive bacteria 3. QS acts as a tool that diversifies physiological activities of bacteria based on cell density and by means of genetic regulation 4…”