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Sikdar R, Beauclaire MV, Lima BP, Herzberg MC, Elias MH. N-acyl homoserine lactone signaling modulates bacterial community associated with human dental plaque. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.15.585217. [PMID: 38559107 PMCID: PMC10980036 DOI: 10.1101/2024.03.15.585217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
N-acyl homoserine lactones (AHLs) are small diffusible signaling molecules that mediate a cell density-dependent bacterial communication system known as quorum sensing (QS). AHL-mediated QS regulates gene expression to control many critical bacterial behaviors including biofilm formation, pathogenicity, and antimicrobial resistance. Dental plaque is a complex multispecies oral biofilm formed by successive colonization of the tooth surface by groups of commensal, symbiotic, and pathogenic bacteria, which can contribute to tooth decay and periodontal diseases. While the existence and roles of AHL-mediated QS in oral microbiota have been debated, recent evidence indicates that AHLs play significant roles in oral biofilm development and community dysbiosis. The underlying mechanisms, however, remain poorly characterized. To better understand the importance of AHL signaling in dental plaque formation, we manipulated AHL signaling by adding AHL lactonases or exogenous AHL signaling molecules. We find that AHLs can be detected in dental plaque grown under 5% CO2 conditions, but not when grown under anaerobic conditions, and yet anaerobic cultures are still responsive to AHLs. QS signal disruption using lactonases leads to changes in microbial population structures in both planktonic and biofilm states, changes that are dependent on the substrate preference of the used lactonase but mainly result in the increase in the abundance of commensal and pioneer colonizer species. Remarkably, the opposite manipulation, that is the addition of exogenous AHLs increases the abundance of late colonizer bacterial species. Hence, this work highlights the importance of AHL-mediated QS in dental plaque communities, its potential different roles in anaerobic and aerobic parts of dental plaque, and underscores the potential of QS interference in the control of periodontal diseases.
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Affiliation(s)
- Rakesh Sikdar
- Biotechnology Institute, University of Minnesota, Saint Paul, MN 55108, USA
| | - Mai V. Beauclaire
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Saint Paul, MN 55108, USA
| | - Bruno P. Lima
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mark C. Herzberg
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Mikael H. Elias
- Biotechnology Institute, University of Minnesota, Saint Paul, MN 55108, USA
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Saint Paul, MN 55108, USA
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Zhao ZZ, Wang J, Liu X, Wang Z, Zheng X, Li W, Cheng T, Zhang J. N-acyl homoserine lactones lactonase est816 suppresses biofilm formation and periodontitis in rats mediated by Aggregatibacter actinomycetemcomitans. J Oral Microbiol 2024; 16:2301200. [PMID: 38193137 PMCID: PMC10773656 DOI: 10.1080/20002297.2023.2301200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 12/28/2023] [Indexed: 01/10/2024] Open
Abstract
Aims The current study aimed to explore the adjuvant therapeutic effect of N-acyl homoserine lactones (AHLs)-lactonase est816 on Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) biological behaviors and periodontitis progression. Methods The inhibitory properties of est816 were detected by live/dead bacterial staining, scanning electron microscope (SEM), crystal-violet staining and reverse-transcription quantitative PCR (RT-qPCR). Biocompatibility of est816 on human gingival fibroblasts (HGFs) and human gingival epithelial cells (HGEs) was evaluated by CCK8 and ELISA. The ligature-induced periodontitis model was established in rats. Micro computed tomography and immunohistochemical and histological staining served to evaluate the effect of est816 on the prevention of periodontitis in vivo. Results est816 significantly attenuated biofilm formation, reduced the mRNA expression of cytolethal distending toxin, leukotoxin and poly-N-acetyl glucosamine (PNAG) and downregulated expressions of interleukin-6 and tumor necrosis factor-α with low cell toxicity. In vivo investigations revealed est816 decreased alveolar bone resorption, suppressed matrix metalloproteinase-9 expression and increased osteoprotegerin expression. Conclusion est816 inhibited A. actinomycetemcomitans biofilm formation and virulence release, resulting in anti-inflammation and soothing of periodontitis in rats, indicating that est816 could be investigated in further research on periodontal diseases.
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Affiliation(s)
- Zelda Ziyi Zhao
- Stomatological Hospital and College, Key Lab. of Oral Diseases Research of Anhui Province, Anhui Medical University, Hefei, Anhui, China
| | - Junmin Wang
- Stomatological Hospital and College, Key Lab. of Oral Diseases Research of Anhui Province, Anhui Medical University, Hefei, Anhui, China
| | - Xinpai Liu
- Stomatological Hospital and College, Key Lab. of Oral Diseases Research of Anhui Province, Anhui Medical University, Hefei, Anhui, China
| | - Zezhi Wang
- Stomatological Hospital and College, Key Lab. of Oral Diseases Research of Anhui Province, Anhui Medical University, Hefei, Anhui, China
| | - Xianyu Zheng
- Stomatological Hospital and College, Key Lab. of Oral Diseases Research of Anhui Province, Anhui Medical University, Hefei, Anhui, China
| | - Wuli Li
- Stomatological Hospital and College, Key Lab. of Oral Diseases Research of Anhui Province, Anhui Medical University, Hefei, Anhui, China
| | - Tianfan Cheng
- Division of Periodontology & Implant Dentistry, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Jing Zhang
- Stomatological Hospital and College, Key Lab. of Oral Diseases Research of Anhui Province, Anhui Medical University, Hefei, Anhui, China
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Lopez Marin MA, Strejcek M, Uhlik O. Joining the bacterial conversation: increasing the cultivation efficiency of soil bacteria with acyl-homoserine lactones and cAMP. Microbiol Spectr 2023; 11:e0186023. [PMID: 37787516 PMCID: PMC10715134 DOI: 10.1128/spectrum.01860-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 08/17/2023] [Indexed: 10/04/2023] Open
Abstract
IMPORTANCE Microorganisms are a repository of interesting metabolites and functions. Therefore, accessing them is an important exercise for advancing not only basic questions about their physiology but also to advance technological applications. In this sense, increasing the culturability of environmental microorganisms remains an important endeavor for modern microbiology. Because microorganisms do not live in isolation in their environments, molecules can be added to the cultivation strategies to "inform them" that they are present in growth-permissive environmental conditions. Signaling molecules such as acyl-homoserine lactones and 3',5'-cyclic adenosine monophosphate belong to the plethora of molecules used by bacteria to communicate with each other in a phenomenon called quorum sensing. Therefore, including quorum sensing molecules can be an incentive for microorganisms, specifically soil bacteria, to increase their numbers on solid media.
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Affiliation(s)
- Marco A. Lopez Marin
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Faculty of Food and Biochemical Technology, Prague, Czech Republic
- Department of Water Technology and Environmental Engineering, University of Chemistry and Technology Prague, Prague, Czechia
| | - Michal Strejcek
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Faculty of Food and Biochemical Technology, Prague, Czech Republic
| | - Ondrej Uhlik
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Faculty of Food and Biochemical Technology, Prague, Czech Republic
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Parga A, Balboa S, Otero-Casal P, Otero A. New Preventive Strategy against Oral Biofilm Formation in Caries-Active Children: An In Vitro Study. Antibiotics (Basel) 2023; 12:1263. [PMID: 37627682 PMCID: PMC10451667 DOI: 10.3390/antibiotics12081263] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 07/27/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023] Open
Abstract
Quorum quenching (QQ) is the inhibition of bacterial communication, i.e., quorum sensing (QS). QS is a key mechanism in regulating biofilm formation and phenotype in complex bacterial communities, such as those found within cariogenic biofilms. Whereas QQ approaches were shown to effectively reduce biomass, knowledge of their impact on the taxonomic composition of oral polymicrobial biofilms remains scarce. Here, we investigate the effect of the QQ lactonase Aii20J on biomass production and taxonomical composition of biofilms. We collected supragingival plaque samples from 10 caries-free and 10 caries-active children and cultured them to generate in vitro biofilms. We describe significant biomass reductions upon Aii20J exposure, as assessed by crystal violet assays. Taxonomical profiling using 16S rRNA gene amplicon sequencing revealed no significant changes in bacterial composition at the genus level. Interestingly, at the species level Aii20J-treatment increased the abundance of Streptococcus cristatus and Streptococcus salivarius. Both S. cristatus and S. salivarius express pH-buffering enzymes (arginine deiminase and urease, respectively) that catalyze ammonia production, thereby potentially raising local pH and counteracting the biofilm's cariogenic potential. Within the limitations of the study, our findings provide evidence of the biofilm-modulating ability of QQ and offer novel insights into alternative strategies to restore homeostasis within dysbiotic ecosystems.
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Affiliation(s)
- Ana Parga
- Department of Microbiology and Parasitology, CIBUS-Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
| | - Sabela Balboa
- Department of Microbiology and Parasitology, Center of Cross-Disciplinary Research in Environmental Technologies (CRETUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Paz Otero-Casal
- Department of Surgery and Medical-Surgical Specialties, Faculty of Medicine and Odontology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
- Unit of Oral Health, Centro de Saúde Santa Comba-Negreira, SERGAS, 15841 Santa Comba, Spain
| | - Ana Otero
- Department of Microbiology and Parasitology, CIBUS-Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain;
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Parga A, Muras A, Otero-Casal P, Arredondo A, Soler-Ollé A, Àlvarez G, Alcaraz LD, Mira A, Blanc V, Otero A. The quorum quenching enzyme Aii20J modifies in vitro periodontal biofilm formation. Front Cell Infect Microbiol 2023; 13:1118630. [PMID: 36816581 PMCID: PMC9932050 DOI: 10.3389/fcimb.2023.1118630] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 01/20/2023] [Indexed: 02/05/2023] Open
Abstract
Introduction Recent studies have revealed the presence of N-acyl-homoserine lactones (AHLs) quorum sensing (QS) signals in the oral environment. Yet, their role in oral biofilm development remains scarcely investigated. The use of quorum quenching (QQ) strategies targeting AHLs has been described as efficient for the control of pathogenic biofilms. Here, we evaluate the use of a highly active AHL-targeting QQ enzyme, Aii20J, to modulate oral biofilm formation in vitro. Methods The effect of the QQ enzyme was studied in in vitro multispecies biofilms generated from oral samples taken from healthy donors and patients with periodontal disease. Subgingival samples were used as inocula, aiming to select members of the microbiota of the periodontal pocket niche in the in vitro biofilms. Biofilm formation abilities and microbial composition were studied upon treating the biofilms with the QQ enzyme Aii20J. Results and Discussion The addition of the enzyme resulted in significant biofilm mass reductions in 30 - 60% of the subgingival-derived biofilms, although standard AHLs could not be found in the supernatants of the cultured biofilms. Changes in biofilm mass were not accompanied by significant alterations of bacterial relative abundance at the genus level. The investigation of 125 oral supragingival metagenomes and a synthetic subgingival metagenome revealed a surprisingly high abundance and broad distribution of homologous of the AHL synthase HdtS and several protein families of AHL receptors, as well as an enormous presence of QQ enzymes, pointing to the existence of an intricate signaling network in oral biofilms that has been so far unreported, and should be further investigated. Together, our findings support the use of Aii20J to modulate polymicrobial biofilm formation without changing the microbiome structure of the biofilm. Results in this study suggest that AHLs or AHL-like molecules affect oral biofilm formation, encouraging the application of QQ strategies for oral health improvement, and reinforcing the importance of personalized approaches to oral biofilm control.
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Affiliation(s)
- Ana Parga
- Department of Microbiology and Parasitology, CIBUS-Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Andrea Muras
- Department of Microbiology and Parasitology, CIBUS-Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Paz Otero-Casal
- Department of Surgery and Medical-Surgical Specialties, Faculty of Medicine and Odontology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
- Unit of Oral Health, Santa Comba-Negreira, (CS) SERGAS, Santiago de Compostela, Spain
| | - Alexandre Arredondo
- Department of Microbiology, Dentaid Research Center, Cerdanyola Del Vallès, Spain
| | - Agnès Soler-Ollé
- Department of Microbiology, Dentaid Research Center, Cerdanyola Del Vallès, Spain
| | - Gerard Àlvarez
- Department of Microbiology, Dentaid Research Center, Cerdanyola Del Vallès, Spain
| | - Luis D. Alcaraz
- Department of Cellular Biology, Faculty of Sciences, National Autonomous University of Mexico, Coyoacán, Mexico
| | - Alex Mira
- Department of Genomics and Health, FISABIO Foundation, Valencia, Spain
| | - Vanessa Blanc
- Department of Microbiology, Dentaid Research Center, Cerdanyola Del Vallès, Spain
| | - Ana Otero
- Department of Microbiology and Parasitology, CIBUS-Faculty of Biology, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
- *Correspondence: Ana Otero,
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Chua KO, Liew YJM, See-Too WS, Tan JY, Yong HS, Yin WF, Chan KG. Formicincola oecophyllae gen. nov. sp. nov., a novel member of the family Acetobacteraceae isolated from the weaver ant Oecophylla smaragdina. Antonie van Leeuwenhoek 2022; 115:995-1007. [DOI: 10.1007/s10482-022-01750-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 05/12/2022] [Indexed: 11/28/2022]
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Quorum-Sensing Inhibition by Gram-Positive Bacteria. Microorganisms 2022; 10:microorganisms10020350. [PMID: 35208805 PMCID: PMC8875677 DOI: 10.3390/microorganisms10020350] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/27/2022] [Accepted: 01/28/2022] [Indexed: 12/01/2022] Open
Abstract
The modern paradigm assumes that interspecies communication of microorganisms occurs through precise regulatory mechanisms. In particular, antagonism between bacteria or bacteria and fungi can be achieved by direct destruction of the targeted cells through the regulated production of antimicrobial metabolites or by controlling their adaptive mechanisms, such as the formation of biofilms. The quorum-quenching phenomenon provides such a countermeasure strategy. This review discusses quorum-sensing suppression by Gram-positive microorganisms, the underlying mechanisms of this process, and its molecular intermediates. The main focus will be on Gram-positive bacteria that have practical applications, such as starter cultures for food fermentation, probiotics, and other microorganisms of biotechnological importance. The possible evolutionary role of quorum-quenching mechanisms during the development of interspecies interactions of bacteria is also considered. In addition, the review provides possible practical applications for these mechanisms, such as the control of pathogens, improving the efficiency of probiotics, and plant protection.
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Oecophyllibacter saccharovorans gen. nov. sp. nov., a bacterial symbiont of the weaver ant Oecophylla smaragdina. J Microbiol 2020; 58:988-997. [DOI: 10.1007/s12275-020-0325-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/19/2020] [Accepted: 09/10/2020] [Indexed: 01/06/2023]
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Muras A, Mallo N, Otero-Casal P, Pose-Rodríguez JM, Otero A. Quorum sensing systems as a new target to prevent biofilm-related oral diseases. Oral Dis 2020; 28:307-313. [PMID: 33080080 DOI: 10.1111/odi.13689] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/23/2020] [Accepted: 10/11/2020] [Indexed: 12/13/2022]
Abstract
OBJECTIVE The present study summarizes the current knowledge on the role of bacterial extracellular signaling systems, known as quorum sensing (QS), in oral biofilm formation, and on the possibility of blocking these microbial communication systems as a potential approach to prevent and treat oral infectious diseases. METHODS A detailed literature review of the current knowledge of QS in the oral cavity was performed, using the databases MEDLINE (through PubMed) and Web of Science. RESULTS Accumulating direct and indirect evidence indicates an important role of QS molecules in the oral microbial ecosystem. CONCLUSIONS The mechanisms regulating gene expression through bacterial communication systems constitute a promising target to control oral biofilm formation. Although cell-to-cell communication is pivotal for biofilm formation of many pathogenic bacteria, knowledge concerning microbial interactions and signaling processes within multispecies biofilms in the oral cavity is still limited.
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Affiliation(s)
- Andrea Muras
- Department of Microbiology and Parasitology, Faculty of Biology-CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Natalia Mallo
- Department of Microbiology and Parasitology, Faculty of Biology-CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Paz Otero-Casal
- Department of Surgery and Medical-Surgical Specialty, Faculty of Medicine and Dentistry, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.,Unit of Oral Health, C.S. Santa Comba-Negreira, SERGAS, Santa Comba, Spain
| | - José M Pose-Rodríguez
- Department of Surgery and Medical-Surgical Specialty, Faculty of Medicine and Dentistry, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Ana Otero
- Department of Microbiology and Parasitology, Faculty of Biology-CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
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Guzman JPMD, De las Alas TPL, Lucban MC, Sevilla CEC. Green tea ( Camellia sinensis) extract inhibits biofilm formation in acyl homoserine lactone-producing, antibiotic-resistant Morganella morganii isolated from Pasig River, Philippines. Heliyon 2020; 6:e05284. [PMID: 33134581 PMCID: PMC7586116 DOI: 10.1016/j.heliyon.2020.e05284] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 08/12/2020] [Accepted: 10/14/2020] [Indexed: 12/25/2022] Open
Abstract
The drastic development of urban districts around the world has caused changes in the environment, specifically on metropolitan waterways such as the Pasig River in the Philippines. These significant changes resulted in diversity of microorganisms and their mechanisms employed such as antibiotic resistance and their communication system or quorum sensing (QS). In this study, four bacterial isolates from Pasig River, identified as Aeromonas salmonicida, Acinetobacter sp., Morganella morganii, and Citrobacter freundii, were observed to employ short-chain acyl homoserine lactone (AHL) as their signalling molecule based on in vitro assays using the biosensor strain Chromobacterium violaceum CV026. Furthermore, M. morganii isolate was shown to be resistant to chloramphenicol. This poses a significant threat not just to public health but also to the aquatic life present in the river. Thus, green tea (Camellia sinensis) extract was tested for its capability to inhibit in vitro biofilm formation in M. morganii, as well as the short-chain acyl homoserine lactone QS system using C. violaceum ATCC 12472. Results showed that the extract significantly (p < 0.05) inhibited biofilm formation in M. morganii at as low as 62.5 μg/mL (31.55%). Increasing the concentration (500 μg/mL) did not significantly (p > 0.05) enhance the activity (41.21%). Furthermore, the extract also inhibited pigmentation in C. violaceum ATCC 12472, suggesting QS inhibition. This study adds into record the production of short-chain AHLs by Aeromonas salmonicida, Acinetobacter sp., Morganella morganii, and Citrobacter freundii, as well as the potential of green tea extract as inhibitor of biofilm formation in antibiotic-resistant M. morganii possibly through QS inhibition.
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Affiliation(s)
- John Paul Matthew D. Guzman
- The Graduate School, University of Santo Tomas, Manila, Philippines
- Environment and Biotechnology Division, Industrial Technology Development Institute, Department of Science and Technology, Taguig City, Philippines
| | - Trisha Pamela L. De las Alas
- The Graduate School, University of Santo Tomas, Manila, Philippines
- Globetek Science Foundation, Inc., Makati City, Philippines
| | - Margie C. Lucban
- The Graduate School, University of Santo Tomas, Manila, Philippines
| | - Christine Eden C. Sevilla
- The Graduate School, University of Santo Tomas, Manila, Philippines
- Service Laboratory, Food and Nutrition Research Institute, Department of Science and Technology, Taguig City, Philippines
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Muras A, Otero-Casal P, Blanc V, Otero A. Acyl homoserine lactone-mediated quorum sensing in the oral cavity: a paradigm revisited. Sci Rep 2020; 10:9800. [PMID: 32555242 PMCID: PMC7300016 DOI: 10.1038/s41598-020-66704-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 05/27/2020] [Indexed: 01/08/2023] Open
Abstract
Acyl homoserine lactones (AHLs), the quorum sensing (QS) signals produced by Gram-negative bacteria, are currently considered to play a minor role in the development of oral biofilm since their production by oral pathogens has not been ascertained thus far. However, we report the presence of AHLs in different oral samples and their production by the oral pathogen Porphyromonas gingivalis. The importance of AHLs is further supported by a very high prevalence of AHL-degradation capability, up to 60%, among bacteria isolated from dental plaque and saliva samples. Furthermore, the wide-spectrum AHL-lactonase Aii20J significantly inhibited oral biofilm formation in different in vitro biofilm models and caused important changes in bacterial composition. Besides, the inhibitory effect of Aii20J on a mixed biofilm of 6 oral pathogens was verified using confocal microscopy. Much more research is needed in order to be able to associate specific AHLs with oral pathologies and to individuate the key actors in AHL-mediated QS processes in dental plaque formation. However, these results indicate a higher relevance of the AHLs in the oral cavity than generally accepted thus far and suggest the potential use of inhibitory strategies against these signals for the prevention and treatment of oral diseases.
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Affiliation(s)
- Andrea Muras
- Departamento de Microbioloxía e Parasitoloxía, Facultade de Bioloxía-CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Paz Otero-Casal
- Departamento de Ciruxía e Especialidade Médico-Cirúrxica, Facultade de Medicina e Odontoloxía, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
- Unit of Oral Health, C.S. Santa Comba-Negreira, SERGAS, Spain
| | - Vanessa Blanc
- Department of Microbiology, Dentaid Research Center, Dentaid S.L., Barcelona, Spain
| | - Ana Otero
- Departamento de Microbioloxía e Parasitoloxía, Facultade de Bioloxía-CIBUS, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
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Short-Chain N-Acylhomoserine Lactone Quorum-Sensing Molecules Promote Periodontal Pathogens in In Vitro Oral Biofilms. Appl Environ Microbiol 2020; 86:AEM.01941-19. [PMID: 31757829 DOI: 10.1128/aem.01941-19] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/11/2019] [Indexed: 12/14/2022] Open
Abstract
Acylhomoserine lactones (AHLs), the quorum-sensing (QS) signals produced by a range of Gram-negative bacteria, are involved in biofilm formation in many pathogenic and environmental bacteria. Nevertheless, the current paradigm excludes a role of AHLs in dental plaque formation, while other QS signals, such as AI-2 and autoinducer peptides, have been demonstrated to play an important role in biofilm formation and virulence-related gene expression in oral pathogens. In the present work, we have explored the effect of externally added AHLs on in vitro oral biofilm models for commensal, cariogenic, and periodontal dental plaque. While little effect on bacterial growth was observed, some AHLs specifically affected the lactic acid production and protease activity of the biofilms. Most importantly, the analysis of bacterial diversity in the biofilms showed that the addition of C6-homoserine lactone (C6-HSL) results in a shift toward a periodontal bacterial composition profile by increasing the relative presence of the orange-complex bacteria Peptostreptococcus and Prevotella These results point to a relevant role of AHL-mediated QS in dental plaque formation and might be involved in the development of dysbiosis, the mechanism of which should be further investigated. This finding potentially opens new opportunities for the prevention or treatment of the periodontal disease.IMPORTANCE Dental plaque is omnipresent in healthy oral cavities and part of our commensal microbial colonization. At the same time, dental plaque is the cause of the most common human diseases, caries and gum disease. Dental plaque consists of billions of microbes attached to the surface of your teeth. Communication among these microbes is pivotal for development of these complex communities yet poorly studied in dental plaque. In the present study, we show that a specific communication molecule induces changes within the community related to the development of gum disease. This finding suggests that interfering with microbial communication may represent an interesting novel strategy to prevent gum disease that should be further investigated.
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Xu Y, Wang C, Hou J, Wang P, You G, Miao L. Effects of cerium oxide nanoparticles on bacterial growth and behaviors: induction of biofilm formation and stress response. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:9293-9304. [PMID: 30725258 DOI: 10.1007/s11356-019-04340-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
In this paper, the effects of cerium oxide nanoparticles (CeO2 NPs) on the group bacterial behaviors were elaborated. After 36-h cultivation, the biofilm biomass was enhanced by the sub-lethal concentrations of 0.5 and 2 mg/L CeO2 NP exposure. Meanwhile, the promoted production of total amino acids in microbes further resulted in the increased surface hydrophobicity and percentage aggregation. To resist the CeO2 NPs stress, the biofilm exhibited a double-layer microstructure, with the protein (PRO) and living cells occupying the bottom, the polysaccharide (PS), and dead cells dominating the top. The bacterial diversity was highly suppressed and Citrobacter and Pseudomonas from the phylum of γ-Proteobacteria strongly dominated the biofilm, indicating the selective and enriched effects of CeO2 NPs on resistant bacteria. The stimulated inherent resistance of biofilm was reflected by the reduced adenosine triphosphate (ATP) content after 4 h exposure. The increased levels of reactive oxygen species (ROS) in the treatments of 8 h CeO2 NP exposure led to the upregulated quorum sensing signals of acylated homoserine lactone (AHL) and autoinducer 2 (AI-2), beneficial to mitigating the environmental disturbance of CeO2 NPs. These results provide evidences for the accelerating effects of CeO2 NPs on biofilm formation through oxidative stress, which expand the understanding of the ecological effects of CeO2 NPs.
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Affiliation(s)
- Yi Xu
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Chao Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Jun Hou
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China.
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Guoxiang You
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
| | - Lingzhan Miao
- Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes of Ministry of Education, College of Environment, Hohai University, 1 Xikang Road, Nanjing, 210098, People's Republic of China
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Characteristics of N-Acylhomoserine Lactones Produced by Hafnia alvei H4 Isolated from Spoiled Instant Sea Cucumber. SENSORS 2017; 17:s17040772. [PMID: 28379194 PMCID: PMC5422045 DOI: 10.3390/s17040772] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 03/22/2017] [Accepted: 04/01/2017] [Indexed: 12/24/2022]
Abstract
This study aimed to identify N-acylhomoserine lactone (AHL) produced by Hafnia alvei H4, which was isolated from spoiled instant sea cucumber, and to investigate the effect of AHLs on biofilm formation. Two biosensor strains, Chromobacterium violaceum CV026 and Agrobacterium tumefaciens KYC55, were used to detect the quorum sensing (QS) activity of H. alvei H4 and to confirm the existence of AHL-mediated QS system. Thin layer chromatography (TLC) and high resolution triple quadrupole liquid chromatography/mass spectrometry (LC/MS) analysis of the AHLs extracted from the culture supernatant of H. alvei H4 revealed the existence of at least three AHLs: N-hexanoyl-l-homoserine lactone (C6-HSL), N-(3-oxo-octanoyl)-l-homoserine lactone (3-oxo-C8-HSL), and N-butyryl-l-homoserine lactone (C4-HSL). This is the first report of the production of C4-HSL by H. alvei. In order to determine the relationship between the production of AHL by H. alvei H4 and bacterial growth, the β-galactosidase assay was employed to monitor AHL activity during a 48-h growth phase. AHLs production reached a maximum level of 134.6 Miller unites at late log phase (after 18 h) and then decreased to a stable level of about 100 Miller unites. AHL production and bacterial growth displayed a similar trend, suggesting that growth of H. alvei H4 might be regulated by QS. The effect of AHLs on biofilm formation of H. alvei H4 was investigated by adding exogenous AHLs (C4-HSL, C6-HSL and 3-oxo-C8-HSL) to H. alvei H4 culture. Biofilm formation was significantly promoted (p < 0.05) by 5 and 10 µM C6-HSL, inhibited (p < 0.05) by C4-HSL (5 and 10 µM) and 5 µM 3-oxo-C8-HSL, suggesting that QS may have a regulatory role in the biofilm formation of H. alvei H4.
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