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Gurunathan S, Thangaraj P, Das J, Kim JH. Antibacterial and antibiofilm effects of Pseudomonas aeruginosa derived outer membrane vesicles against Streptococcus mutans. Heliyon 2023; 9:e22606. [PMID: 38125454 PMCID: PMC10730581 DOI: 10.1016/j.heliyon.2023.e22606] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 11/09/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023] Open
Abstract
Antimicrobial resistance (AMR) is a serious and most urgent global threat to human health. AMR is one of today's biggest difficulties in the health system and has the potential to harm people at any stage of life, making it a severe public health issue. There must be fewer antimicrobial medicines available to treat diseases given the rise in antibiotic-resistant organisms. If no new drugs are created or discovered, it is predicted that there won't be any effective antibiotics accessible by 2050. In most cases, Streptococcus increased antibiotic resistance by forming biofilms, which account for around 80 % of all microbial infections in humans. This highlights the need to look for new strategies to manage diseases that are resistant to antibiotics. Therefore, development alternative, biocompatible and high efficacy new strategies are essential to overcome drug resistance. Recently, bacterial derived extracellular vesicles have been applied to tackle infection and reduce the emergence of drug resistance. Therefore, the objective of the current study was designed to assess the antibacterial and antibiofilm potential of outer membrane vesicles (OMVs) derived from Pseudomonas aeruginosa againstStreptococcus mutans. According to the findings of this investigation, the pure P. aeruginosa outer membrane vesicles (PAOMVs) display a size of 100 nm. S. mutans treated with PAOMVs showed significant antibacterial and antibiofilm activity. The mechanistic studies revealed that PAOMVs induce cell death through excessive generation of reactive oxygen species and imbalance of redox leads to lipid peroxidation, decreased level of antioxidant markers including glutathione, superoxide dismutase and catalase. Further this study confirmed that PAOMVs significantly impairs metabolic activity through inhibiting lactate dehydrogenase activity (LDH), adenosine triphosphate (ATP) production, leakage of proteins and sugars. Interestingly, combination of sub-lethal concentrations of PAOMVs and antibiotics enhances cell death and biofilm formation of S. mutans. Altogether, this work, may serve as an important basis for further evaluation of PAOMVs as novel therapeutic agents against bacterial infections.
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Affiliation(s)
- Sangiliyandi Gurunathan
- Department of Biotechnology, Rathinam College of Arts and Science, Rathinam Techzone Campus, Eachanari, Coimbatore, 641 021, Tamil Nadu, India
| | - Pratheep Thangaraj
- Department of Biotechnology, Rathinam College of Arts and Science, Rathinam Techzone Campus, Eachanari, Coimbatore, 641 021, Tamil Nadu, India
| | - Joydeep Das
- Department of Chemistry, Mizoram University, Aizawl, 796 004, Mizoram, India
| | - Jin-Hoi Kim
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, Seoul, 05029, South Korea
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Zuber P, Kreth J. Aspects of oral streptococcal metabolic diversity: Imagining the landscape beneath the fog. Mol Microbiol 2023; 120:508-524. [PMID: 37329112 DOI: 10.1111/mmi.15106] [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: 03/15/2023] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/18/2023]
Abstract
It is widely acknowledged that the human-associated microbial community influences host physiology, systemic health, disease progression, and even behavior. There is currently an increased interest in the oral microbiome, which occupies the entryway to much of what the human initially encounters from the environment. In addition to the dental pathology that results from a dysbiotic microbiome, microbial activity within the oral cavity exerts significant systemic effects. The composition and activity of the oral microbiome is influenced by (1) host-microbial interactions, (2) the emergence of niche-specific microbial "ecotypes," and (3) numerous microbe-microbe interactions, shaping the underlying microbial metabolic landscape. The oral streptococci are central players in the microbial activity ongoing in the oral cavity, due to their abundance and prevalence in the oral environment and the many interspecies interactions in which they participate. Streptococci are major determinants of a healthy homeostatic oral environment. The metabolic activities of oral Streptococci, particularly the metabolism involved in energy generation and regeneration of oxidative resources vary among the species and are important factors in niche-specific adaptations and intra-microbiome interactions. Here we summarize key differences among streptococcal central metabolic networks and species-specific differences in how the key glycolytic intermediates are utilized.
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Affiliation(s)
- Peter Zuber
- Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, Oregon, USA
| | - Jens Kreth
- School of Dentistry, Oregon Health & Science University, Portland, Oregon, USA
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Jiang W, Xie Z, Huang S, Huang Q, Chen L, Gao X, Lin Z. Targeting cariogenic pathogens and promoting competitiveness of commensal bacteria with a novel pH-responsive antimicrobial peptide. J Oral Microbiol 2022; 15:2159375. [PMID: 36570976 PMCID: PMC9788686 DOI: 10.1080/20002297.2022.2159375] [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] [Indexed: 12/24/2022] Open
Abstract
Novel ecological antimicrobial approaches to dental caries focus on inhibiting cariogenic pathogens while enhancing the growth of health-associated commensal communities or suppressing cariogenic virulence without affecting the diversity of oral microbiota, which emphasize the crucial role of establishing a healthy microbiome in caries prevention. Considering that the acidified cariogenic microenvironment leads to the dysbiosis of microecology and demineralization of enamel, exploiting the acidic pH as a bioresponsive trigger to help materials and medications target cariogenic pathogens is a promising strategy to develop novel anticaries approaches. In this study, a pH-responsive antimicrobial peptide, LH12, was designed utilizing the pH-sensitivity of histidine, which showed higher cationicity and stronger interactions with bacterial cytomembranes at acidic pH. Streptococcus mutans was used as the in vitro caries model to evaluate the inhibitory effects of LH12 on the cariogenic properties, such as biofilm formation, biofilm morphology, acidurance, acidogenicity, and exopolysaccharides synthesis. The dual-species model of Streptococcus mutans and Streptococcus gordonii was established in vitro to evaluate the regulation effects of LH12 on the mixed species microbial community containing both cariogenic bacteria and commensal bacteria. LH12 suppressed the cariogenic properties and regulated the bacterial composition to a healthier condition through a dual-functional mechanism. Firstly, LH12-targeted cariogenic pathogens in response to the acidified microenvironment and suppressed the cariogenic virulence by inhibiting the expression of multiple virulence genes and two-component signal transduction systems. Additionally, LH12 elevated H2O2 production of the commensal bacteria and subsequently improved the ecological competitiveness of the commensals. The dual-functional mechanism made LH12 a potential bioresponsive approach to caries management.
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Affiliation(s)
- Wentao Jiang
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, GuangdongChina
| | - Zhuo Xie
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, GuangdongChina
| | - Shuheng Huang
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, GuangdongChina
| | - Qiting Huang
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, GuangdongChina
| | - Lingling Chen
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, GuangdongChina
| | - Xianling Gao
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, GuangdongChina
| | - Zhengmei Lin
- Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, GuangdongChina,CONTACT Zhengmei Lin Hospital of Stomatology, Guangdong Provincial Key Laboratory of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong510055, China
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Zeng L, Walker AR, Calderon PDS, Xia X, Ren F, Esquivel-Upshaw JF. The Effect of Amino Sugars on the Composition and Metabolism of a Microcosm Biofilm and the Cariogenic Potential against Teeth and Dental Materials. J Funct Biomater 2022; 13:223. [PMID: 36412864 PMCID: PMC9680229 DOI: 10.3390/jfb13040223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/18/2022] [Accepted: 10/24/2022] [Indexed: 11/09/2022] Open
Abstract
Amino sugars N-acetylglucosamine (GlcNAc) and glucosamine (GlcN) are abundant sources of carbon and nitrogen in the oral cavity. The aim of this study was to investigate the effects of GlcNAc metabolism on the genomics and biochemistry of a saliva-derived microbial community, and on the surface integrity of human teeth and restorative surfaces. Pooled cell-containing saliva (CCS) was used to establish a microcosm biofilm in vitro in a biofilm medium (BM) containing 5 different carbohydrates. The microbial composition of each biofilm was analyzed by 16S rRNA amplicon sequencing, and the concentrations of eight organic acids were determined for selected sugars by targeted metabolomics. Meanwhile, extracted human teeth and polished titanium and ceramic disks were submerged in BM supplemented with 1% of glucose or GlcNAc, inoculated with CCS and Streptococcus mutans UA159, and incubated for 30 days. To mimic the effects of other microbial byproducts, the specimens were immersed in 10 mM hydrogen peroxide and 10 mM ammonium hydroxide for 30 days. The surface of each specimen was evaluated by profilometry for roughness (Ra) and imaged by scanning electron microscopy. The pH of the biofilm supernatant was significantly higher for the medium containing GlcNAc (p < 0.0001), and was higher in samples containing teeth than the two restorative disks for media containing the same sugar. For both teeth and titanium specimens, the samples treated with glucose-biofilm presented higher roughness values (Ra) than those with GlcNAc-biofilm and every other group. SEM images of the teeth and titanium disks largely supported the profilometry results, with glucose-biofilm samples demonstrating the largest deviation from the reference. For ceramic disks, slightly higher Ra values were obtained for the ammonia group. These findings provide the first direct evidence to support the ability of amino sugars to significantly reduce the cariogenic potential of oral biofilms by altering their biochemistry and bacterial composition. Additionally, amino sugar metabolism appears to be less detrimental to teeth and restorative surfaces than glucose metabolism.
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Affiliation(s)
- Lin Zeng
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, FL 32610, USA
| | - Alejandro Riveros Walker
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, FL 32610, USA
| | | | - Xinyi Xia
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Fan Ren
- Department of Chemical Engineering, University of Florida, Gainesville, FL 32611, USA
| | - Josephine F. Esquivel-Upshaw
- Department of Restorative Dental Sciences, Division of Prosthodontics, University of Florida, Gainesville, FL 32611, USA
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Akimbekov NS, Digel I, Yerezhepov AY, Shardarbek RS, Wu X, Zha J. Nutritional factors influencing microbiota-mediated colonization resistance of the oral cavity: A literature review. Front Nutr 2022; 9:1029324. [PMID: 36337619 PMCID: PMC9630914 DOI: 10.3389/fnut.2022.1029324] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 10/06/2022] [Indexed: 11/07/2023] Open
Abstract
The oral cavity is a key biocenosis for many distinct microbial communities that interact with both the external environment and internal body systems. The oral microbiota is a vital part of the human microbiome. It has been developed through mutual interactions among the environment, host physiological state, and microbial community composition. Indigenious microbiota of the oral cavity is one of the factors that prevent adhesion and invasion of pathogens on the mucous membrane, i.e., the development of the infectious process and thereby participating in the implementation of one of the mechanisms of local immunity-colonization resistance. The balance between bacterial symbiosis, microbial virulence, and host resistance ensures the integrity of the oral cavity. In this review we have tried to address how nutritional factors influence integrity of the oral indigenous microbiota and its involvement in colonization resistance.
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Affiliation(s)
- Nuraly S. Akimbekov
- Department of Biotechnology, Al-Farabi Kazakh National University, Almaty, Kazakhstan
| | - Ilya Digel
- Institute for Bioengineering, FH Aachen University of Applied Sciences, Jülich, Germany
| | - Adil Y. Yerezhepov
- Department of Biotechnology, Al-Farabi Kazakh National University, Almaty, Kazakhstan
| | - Raiymbek S. Shardarbek
- Department of Internal Diseases, Kazakh National Medical University Named After S.D. Asfendiyarov, Almaty, Kazakhstan
| | - Xia Wu
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi’an, China
| | - Jian Zha
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi’an, China
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Yuan K, Hou L, Jin Q, Niu C, Mao M, Wang R, Huang Z. Comparative transcriptomics analysis of Streptococcus mutans with disruption of LuxS/AI-2 quorum sensing and recovery of methyl cycle. Arch Oral Biol 2021; 127:105137. [PMID: 33965851 DOI: 10.1016/j.archoralbio.2021.105137] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 04/23/2021] [Accepted: 04/24/2021] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The LuxS/AI-2 quorum sensing (QS) system has critical roles in Streptococcus mutans cariogenicity. Whereas the molecular and cellular mechanisms of the LuxS/AI-2 QS system are not thoroughly understood. Given that LuxS has roles in QS and methyl cycle, its mutation can cause QS deficiency and methyl cycle disruption. The aim of this study was to investigate effects of the LuxS/AI-2 QS system on gene expression in Streptococcus mutans when methyl cycle was recovered with exogenous sahH gene. METHODS Our previous study introduced the exogenous sahH gene from Pseudomonas aeruginosa into an S. mutans luxS-null strain to restore the disrupted methyl cycle, and this produced the solely the LuxS/AI-2 QS system deficient strain. Here, we analyzed the transcriptomics of this strain to get insights into the molecular mechanisms of the LuxS/AI-2 QS system applying RNA-seq. RESULTS With recovery of methyl cycle, 84 genes didn't change in expression trends in S. mutans luxS-null strain. These genes mainly encode the ABC transporters, sugar transporter EII and enzymes of carbohydrate metabolism, and are rich in the Phosphotransferase system, Fructose and mannose metabolism, Amino sugar and nucleotide sugar metabolism, Galactose metabolism, Glycolysis/Gluconeogenesis, RNA degradation, Lysine biosynthesis, and Glycine, serine and threonine metabolism. CONCLUSIONS The LuxS/AI-2 QS system may mainly affect ABC transporters and carbohydrate transport, transformation and metabolism via EII subunits and enzymes to influence virulence-associated traits without effects of methyl cycle inStreptococcus mutans.
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Affiliation(s)
- Keyong Yuan
- Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai JiaoTong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China
| | - Lili Hou
- Department of Nursing, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Qiaoqiao Jin
- Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai JiaoTong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China
| | - Chenguang Niu
- Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai JiaoTong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China
| | - Mengying Mao
- Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai JiaoTong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China
| | - Ruirui Wang
- Department of Stomatology, Minhang Branch, Zhongshan Hospital, Fudan University, China.
| | - Zhengwei Huang
- Department of Endodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai JiaoTong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, China.
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Paul B, Sierra MA, Xu F, Crystal YO, Li X, Saxena D, Ruff RR. Microbial population shift and metabolic characterization of silver diamine fluoride treatment failure on dental caries. PLoS One 2021; 16:e0242396. [PMID: 33720954 PMCID: PMC7959385 DOI: 10.1371/journal.pone.0242396] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 01/22/2021] [Indexed: 11/25/2022] Open
Abstract
The objective of this pilot study was to describe the microbial profiles present in the plaque and saliva of children who continued to develop new carious lesions following treatment with silver diamine fluoride ("nonresponders") compared to caries active, caries-free, and children immediately receiving SDF treatment for untreated caries in order to identify potential microbial differences that may relate to a re-incidence of caries. Saliva and plaque samples from infected and contralateral sites were obtained from twenty children who were either caries free, had active carious lesions, were caries active and received SDF treatment immediately before sampling, or had previously received SDF treatment and developed new caries. In total, 8,057,899 Illumina-generated sequence reads from 60 samples were obtained. Reads were processed using the Quantitative Insights Into Microbial Ecology pipeline. Group differences were assessed using Analysis of Variance Models and Tukey Honest Significant Differences. To identify significant taxa between treatment groups, Linear discriminant analysis Effect Size (LefSe) and Analysis of Differential Abundance Taking Sample Variation Into Account were used. Differential abundant analysis indicated that members of the Lachnospiraceae family were significantly enriched in non-responders and the genus Tannerella and species Granulicatella adiances were also highly abundant in this group. LefSe analysis between non-responders and SDF-treated groups revealed that genera Leptotrichia and Granulicatella were enriched in non-responders. We observed the highest abundance of phosphotransferase system and lowest abundance of lipopolysaccharide synthesis in non-responders. The microbiome in dental biofilms is responsible for initiation and progression of dental caries. SDF has been shown to be effective in arresting the progression carious lesions, in part due to its antimicrobial properties. Findings suggest that the differential abundance of select microbiota and specific pathway functioning in individuals that present with recurrent decay after SDF treatment may contribute to a potential failure of silver diamine fluoride to arrest dental caries. However, the short duration of sample collection following SDF application and the small sample size emphasize the need for further data and additional analysis.
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Affiliation(s)
- Bidisha Paul
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, United States of America
| | - Maria A. Sierra
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, United States of America
| | - Fangxi Xu
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, United States of America
| | - Yasmi O. Crystal
- Department of Pediatric Dentistry, New York University College of Dentistry, New York, New York, United States of America
| | - Xin Li
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, United States of America
| | - Deepak Saxena
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, New York, United States of America
| | - Ryan Richard Ruff
- Department of Epidemiology and Health Promotion, New York University College of Dentistry, New York, New York, United States of America
- New York University College of Global Public Health, New York, New York, United States of America
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Sridharan AP, Sugitha T, Karthikeyan G, Nakkeeran S, Sivakumar U. Metabolites of Trichoderma longibrachiatum EF5 inhibits soil borne pathogen, Macrophomina phaseolina by triggering amino sugar metabolism. Microb Pathog 2020; 150:104714. [PMID: 33383148 DOI: 10.1016/j.micpath.2020.104714] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 12/18/2020] [Accepted: 12/21/2020] [Indexed: 01/07/2023]
Abstract
An endophytic fungal antagonist Trichoderma longibrachiatum EF5 exhibited biocontrol activity against a soil-borne fungal pathogen Macrophomina phaseolina. Under dual co-culture, T. longibrachiatum EF5 showed 58% inhibition against M. phaseolina. Crude soluble metabolites (SMs) extracted from EF5 exhibited biocontrol activity (61%), which is more significant than the cell-free extract. Dual culture of both T. longibrachiatum EF5 and M. phaseolina displayed entangled mycelial structures and retarded hyphal growth. The metabolites responsible for antibiosis and pathogenic activity profiled through GC-MS revealed a total of 131 SMs from axenic culture and upon the interaction of T. longibrachiatum EF5 and M. phaseolina. Interestingly, potential plant-growth-promoting and antimicrobial compounds such as 1- pentanol, 1-hexanol, myristonyl pantothenate, bisabolol, d-Alanine, and diethyl trisulphide were unique with T. longibrachiatum EF5. Few compounds that were not observed or produced minimally under axenic culture were increased during their interaction (e.g., 1,6-anhydro-á-d-Glucopyranose and 5-heptyl dihydro-2(3H)-Furanone), suggesting antimicrobial action against the pathogen. This study also unraveled the induction of amino sugar metabolism when T. longibrachiatum EF5 interacts with M. phaseolina, which is responsible for colonization and counterfeiting the pathogen. Hence T. longibrachiatum EF5 could be a potential biocontrol agent employed for defense priming and plant growth promotion.
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Affiliation(s)
- A P Sridharan
- Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, 641003, India
| | - Thangappan Sugitha
- Biocatalysts Laboratory, Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, 641003, India
| | - G Karthikeyan
- Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, 641003, India
| | - S Nakkeeran
- Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, 641003, India
| | - Uthandi Sivakumar
- Biocatalysts Laboratory, Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, 641003, India.
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Amino Sugars Reshape Interactions between Streptococcus mutans and Streptococcus gordonii. Appl Environ Microbiol 2020; 87:AEM.01459-20. [PMID: 33097515 DOI: 10.1128/aem.01459-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/13/2020] [Indexed: 12/19/2022] Open
Abstract
Amino sugars, particularly glucosamine (GlcN) and N-acetylglucosamine (GlcNAc), are abundant carbon and nitrogen sources supplied in host secretions and in the diet to the biofilms colonizing the human oral cavity. Evidence is emerging that these amino sugars provide ecological advantages to beneficial commensals over oral pathogens and pathobionts. Here, we performed transcriptome analysis on Streptococcus mutans and Streptococcus gordonii growing in single-species or dual-species cultures with glucose, GlcN, or GlcNAc as the primary carbohydrate source. Compared to glucose, GlcN caused drastic transcriptomic shifts in each species of bacteria when it was cultured alone. Likewise, cocultivation in the presence of GlcN yielded transcriptomic profiles that were dramatically different from the single-species results from GlcN-grown cells. In contrast, GlcNAc elicited only minor changes in the transcriptome of either organism in single- and dual-species cultures. Interestingly, genes involved in pyruvate metabolism were among the most significantly affected by GlcN in both species, and these changes were consistent with measurements of pyruvate in culture supernatants. Differing from what was found in a previous report, growth of S. mutans alone with GlcN inhibited the expression of multiple operons required for mutacin production. Cocultivation with S. gordonii consistently increased the expression of two manganese transporter operons (slo and mntH) and decreased expression of mutacin genes in S. mutans Conversely, S. gordonii appeared to be less affected by the presence of S. mutans but did show increases in genes for biosynthetic processes in the cocultures. In conclusion, amino sugars profoundly alter the interactions between pathogenic and commensal streptococci by reprogramming central metabolism.IMPORTANCE Carbohydrate metabolism is central to the development of dental caries. A variety of sugars available to dental microorganisms influence the development of caries by affecting the physiology, ecology, and pathogenic potential of tooth biofilms. Using two well-characterized oral bacteria, one pathogen (Streptococcus mutans) and one commensal (Streptococcus gordonii), in an RNA deep-sequencing analysis, we studied the impact of two abundant amino sugars on bacterial gene expression and interspecies interactions. The results indicated large-scale remodeling of gene expression induced by GlcN in particular, affecting bacterial energy generation, acid production, protein synthesis, and release of antimicrobial molecules. Our study provides novel insights into how amino sugars modify bacterial behavior, information that will be valuable in the design of new technologies to detect and prevent oral infectious diseases.
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Guo Y, Wang Y, Wang Y, Jin Y, Wang C. Heme Competition Triggers an Increase in the Pathogenic Potential of Porphyromonas gingivalis in Porphyromonas gingivalis-Candida albicans Mixed Biofilm. Front Microbiol 2020; 11:596459. [PMID: 33343538 PMCID: PMC7738433 DOI: 10.3389/fmicb.2020.596459] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022] Open
Abstract
As one of the main pathogens of periodontitis, Porphyromonas gingivalis often forms mixed biofilms with other bacteria or fungi under the gingiva, such as Candida albicans. Heme is an important iron source for P. gingivalis and C. albicans that supports their growth in the host. From the perspective of heme competition, this study aims to clarify that the competition for heme enhances the pathogenic potential of P. gingivalis during the interaction between P. gingivalis and C. albicans. Porphyromonas gingivalis single-species biofilm and P. gingivalis-C. albicans dual-species biofilm were established in a low- and high-heme environment. The results showed that the vitality of P. gingivalis was increased in the dual-species biofilm under the condition of low heme, and the same trend was observed under a laser confocal microscope. Furthermore, the morphological changes in P. gingivalis were observed by electron microscope, and the resistance of P. gingivalis in dual-species biofilm was stronger against the killing effect of healthy human serum and antibiotics. The ability of P. gingivalis to agglutinate erythrocyte was also enhanced in dual-species biofilm. These changes disappeared when heme was sufficient, which confirmed that heme competition was the cause of thepathogenicy change in P. gingivalis. Gene level analysis showed that P. gingivalis was in a superior position in the competition relationship by increasing the expression of heme utilization-related genes, such as HmuY, HmuR, HusA, and Tlr. In addition, the expression of genes encoding gingipains (Kgp, RgpA/B) was also significantly increased. They not only participate in the process of utilizing heme, but also are important components of the virulence factors of P. gingivalis. In conclusion, our results indicated that the pathogenic potential of P. gingivalis was enhanced by C. albicans through heme competition, which ultimately promoted the occurrence and development of periodontitis and, therefore, C. albicans subgingival colonization should be considered as a factor in assessing the risk of periodontitis.
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Affiliation(s)
- Yanyang Guo
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yu Wang
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yijin Wang
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yabing Jin
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Chen Wang
- Jiangsu Key Laboratory of Oral Diseases, Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
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Wang X, Huang Z, Wang C, Qi C, Gu Z, Li E, Qin JG, Chen L. A Comparative Study on Growth and Metabolism of Eriocheir sinensis Juveniles Under Chronically Low and High pH Stress. Front Physiol 2020; 11:885. [PMID: 32792987 PMCID: PMC7385324 DOI: 10.3389/fphys.2020.00885] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 06/29/2020] [Indexed: 01/27/2023] Open
Abstract
This study elucidates the effects of chronic pH stress on the growth and metabolic response of juvenile Chinese mitten crab Eriocheir sinensis. Crabs were exposed under normal pH (control, pH = 8.0 ± 0.20), low pH (pH = 6.5 ± 0.20), and high pH (pH = 9.5 ± 0.20) in an 8-week trial. Both low and high pH suppressed weight gain but low pH had more adverse effects. No difference was observed on survival, crude lipid, and protein. Acidic stress significantly reduced protein efficiency. The malondialdehyde (MDA) content in hepatopancreas was highest at low pH. The superoxide dismutase (SOD) activity in hepatopancreas and total hemocyte counts (THC) in the stress groups were higher than that in the control. Crabs under high pH had the highest ACP and AKP activities, but there was no significant difference between the control and low pH groups. In the transcriptome analysis, 500.0M clean reads were obtained from the control, low pH, and high pH groups, and assembled into 83,025 transcripts. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed to obtain the significantly changed pathways involving differently expressed genes. Ten and eight pathways in metabolism were significantly changed in low pH vs control and high pH vs control groups, respectively. According to the reported functions of these pathways, most of them participated in carbohydrate metabolism. The metabolism pathway analysis indicates the increases of stress resistance, glucose metabolism, and molting activities under chronically pH stress. This study suggests that low pH has more negative impact on crab growth, and oxidative phosphorylation is the main source of energy source under low pH stress, while aerobic glycolysis supplies most energy under high pH stress.
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Affiliation(s)
- Xiaodan Wang
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhipeng Huang
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Chunling Wang
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Changle Qi
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
| | - Zhimin Gu
- Agriculture Ministry Key Laboratory of Healthy Freshwater Aquaculture, Key Laboratory of Freshwater Aquaculture Genetic and Breeding of Zhejiang Province, Zhejiang Institute of Freshwater Fisheries, Huzhou, China
| | - Erchao Li
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China.,Department of Aquaculture, College of Marine Sciences, Hainan University, Haikou, China
| | - Jian G Qin
- Department of Biological Sciences, College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Liqiao Chen
- Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China
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Fujiki M, Honda M. The investigation of synergistic activity of protamine with conventional antimicrobial agents against oral bacteria. Biochem Biophys Res Commun 2020; 523:561-566. [PMID: 31932035 DOI: 10.1016/j.bbrc.2020.01.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 01/02/2020] [Indexed: 11/18/2022]
Abstract
In this study, we applied protamine, which is an antimicrobial peptide, to oral healthcare in combination with conventional antimicrobial agents. First, we explored the antimicrobial activity of protamine, with or without other antimicrobial agents, against Streptococcus mutans (S. mutans). Co-treatment with protamine and 3-methyl-4-isopropylphenol (IPMP) decreased the viability of S. mutans synergistically within 10 min. Interestingly, sodium fluoride (NaF) did not exhibit synergistic activity with protamine. Next, S. mutans and Streptococcus gordonii (S. gordonii) were co-treated with protamine and IPMP for 5 min to simulate tooth brushing. As a result, this co-treatment killed S. mutans faster than S. gordonii. Therefore, co-treatment with protamine and IPMP could be incorporated into oral healthcare products to prevent dental caries.
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Affiliation(s)
- Masashi Fujiki
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan
| | - Michiyo Honda
- Department of Applied Chemistry, School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
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Novel Probiotic Mechanisms of the Oral Bacterium Streptococcus sp. A12 as Explored with Functional Genomics. Appl Environ Microbiol 2019; 85:AEM.01335-19. [PMID: 31420345 DOI: 10.1128/aem.01335-19] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/14/2019] [Indexed: 12/11/2022] Open
Abstract
Health-associated biofilms in the oral cavity are composed of a diverse group of microbial species that can foster an environment that is less favorable for the outgrowth of dental caries pathogens, like Streptococcus mutans A novel oral bacterium, designated Streptococcus A12, was previously isolated from supragingival dental plaque of a caries-free individual and was shown to interfere potently with the growth and virulence properties of S. mutans In this study, we applied functional genomics to begin to identify molecular mechanisms used by A12 to antagonize, and to resist the antagonistic factors of, S. mutans Using bioinformatics, genes that could encode factors that enhance the ability of A12 to compete with S. mutans were identified. Selected genes, designated potential competitive factors (pcf), were deleted. Certain mutant derivatives showed a reduced capacity to compete with S. mutans compared to that of the parental strain. The A12 pcfO mutant lost the ability to inhibit comX -inducing peptide (XIP) signaling by S. mutans, while mutants with changes in the pcfFEG locus were impaired in sensing of, and were more sensitive to, the lantibiotic nisin. Loss of PcfV, annotated as a colicin V biosynthetic protein, resulted in diminished antagonism of S. mutans Collectively, the data provide new insights into the complexities and variety of factors that affect biofilm ecology and virulence. Continued exploration of the genomic and physiological factors that distinguish commensals from truly beneficial members of the oral microbiota will lead to a better understanding of the microbiome and new approaches to promote oral health.IMPORTANCE Advances in defining the composition of health-associated biofilms have highlighted the important role of beneficial species in maintaining health. Comparatively little, however, has been done to address the genomic and physiological bases underlying the probiotic mechanisms of beneficial commensals. In this study, we explored the ability of a novel oral bacterial isolate, Streptococcus A12, to compete with the dental pathogen Streptococcus mutans using various gene products with diverse functions. A12 displayed enhanced competitiveness by (i) disrupting intercellular communication pathways of S. mutans, (ii) sensing and resisting antimicrobial peptides, and (iii) producing factors involved in the production of a putative antimicrobial compound. Research on the probiotic mechanisms employed by Streptococcus A12 is providing essential insights into how beneficial bacteria may help maintain oral health, which will aid in the development of biomarkers and therapeutics that can improve the practice of clinical dentistry.
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Amino Sugars Modify Antagonistic Interactions between Commensal Oral Streptococci and Streptococcus mutans. Appl Environ Microbiol 2019; 85:AEM.00370-19. [PMID: 30877119 DOI: 10.1128/aem.00370-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/12/2019] [Indexed: 02/05/2023] Open
Abstract
N-Acetylglucosamine (GlcNAc) and glucosamine (GlcN) enhance the competitiveness of the laboratory strain DL1 of Streptococcus gordonii against the caries pathogen Streptococcus mutans Here, we examine how amino sugars affect the interaction of five low-passage-number clinical isolates of abundant commensal streptococci with S. mutans by utilizing a dual-species biofilm model. Compared to that for glucose, growth on GlcN or GlcNAc significantly reduced the viability of S. mutans in cocultures with most commensals, shifting the proportions of species. Consistent with these results, production of H2O2 was increased in most commensals when growing on amino sugars, and inhibition of S. mutans by Streptococcus cristatus, Streptococcus oralis, or S. gordonii was enhanced by amino sugars on agar plates. All commensals except S. oralis had higher arginine deiminase activities when grown on GlcN and, in some cases, GlcNAc. In ex vivo biofilms formed using pooled cell-containing saliva (CCS), the proportions of S. mutans were drastically diminished when GlcNAc was the primary carbohydrate. Increased production of H2O2 could account in large part for the inhibitory effects of CCS biofilms. Surprisingly, amino sugars appeared to improve mutacin production by S. mutans on agar plates, suggesting that the commensals have mechanisms to actively subvert antagonism by S. mutans in cocultures. Collectively, these findings demonstrate that amino sugars can enhance the beneficial properties of low-passage-number commensal oral streptococci and highlight their potential for moderating the cariogenicity of oral biofilms.IMPORTANCE Dental caries is driven by dysbiosis of oral biofilms in which dominance by acid-producing and acid-tolerant bacteria results in loss of tooth mineral. Our previous work demonstrated the beneficial effects of amino sugars GlcNAc and GlcN in promoting the antagonistic properties of a health-associated oral bacterium, Streptococcus gordonii, in competition with the major caries pathogen Streptococcus mutans Here, we investigated 5 low-passage-number clinical isolates of the most common streptococcal species to establish how amino sugars may influence the ecology and virulence of oral biofilms. Using multiple in vitro models, including a human saliva-derived microcosm biofilm, experiments showed significant enhancement by at least one amino sugar in the ability of most of these bacteria to suppress the caries pathogen. Therefore, our findings demonstrated the mechanism of action by which amino sugars may affect human oral biofilms to promote health.
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Zeng L, Burne RA. Essential Roles of the sppRA Fructose-Phosphate Phosphohydrolase Operon in Carbohydrate Metabolism and Virulence Expression by Streptococcus mutans. J Bacteriol 2019; 201:e00586-18. [PMID: 30348833 PMCID: PMC6304665 DOI: 10.1128/jb.00586-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 10/16/2018] [Indexed: 11/20/2022] Open
Abstract
The dental caries pathogen Streptococcus mutans can ferment a variety of sugars to produce organic acids. Exposure of S. mutans to certain nonmetabolizable carbohydrates, such as xylitol, impairs growth and can cause cell death. Recently, the presence of a sugar-phosphate stress in S. mutans was demonstrated using a mutant lacking 1-phosphofructokinase (FruK) that accumulates fructose-1-phosphate (F-1-P). Here, we studied an operon in S. mutans, sppRA, which was highly expressed in the fruK mutant. Biochemical characterization of a recombinant SppA protein indicated that it possessed hexose-phosphate phosphohydrolase activity, with preferences for F-1-P and, to a lesser degree, fructose-6-phosphate (F-6-P). SppA activity was stimulated by Mg2+ and Mn2+ but inhibited by NaF. SppR, a DeoR family regulator, repressed the expression of the sppRA operon to minimum levels in the absence of the fructose-derived metabolite F-1-P and likely also F-6-P. The accumulation of F-1-P, as a result of growth on fructose, not only induced sppA expression, but it significantly altered biofilm maturation through increased cell lysis and enhanced extracellular DNA release. Constitutive expression of sppA, via a plasmid or by deleting sppR, greatly alleviated fructose-induced stress in a fruK mutant, enhanced resistance to xylitol, and reversed the effects of fructose on biofilm formation. Finally, by identifying three additional putative phosphatases that are capable of promoting sugar-phosphate tolerance, we show that S. mutans is capable of mounting a sugar-phosphate stress response by modulating the levels of certain glycolytic intermediates, functions that are interconnected with the ability of the organism to manifest key virulence behaviors.IMPORTANCEStreptococcus mutans is a major etiologic agent for dental caries, primarily due to its ability to form biofilms on the tooth surface and to convert carbohydrates into organic acids. We have discovered a two-gene operon in S. mutans that regulates fructose metabolism by controlling the levels of fructose-1-phosphate, a potential signaling compound that affects bacterial behaviors. With fructose becoming increasingly common and abundant in the human diet, we reveal the ways that fructose may alter bacterial development, stress tolerance, and microbial ecology in the oral cavity to promote oral diseases.
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Affiliation(s)
- Lin Zeng
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
| | - Robert A Burne
- Department of Oral Biology, University of Florida, Gainesville, Florida, USA
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Marsh PD, Zaura E. Dental biofilm: ecological interactions in health and disease. J Clin Periodontol 2018; 44 Suppl 18:S12-S22. [PMID: 28266111 DOI: 10.1111/jcpe.12679] [Citation(s) in RCA: 244] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND The oral microbiome is diverse and exists as multispecies microbial communities on oral surfaces in structurally and functionally organized biofilms. AIM To describe the network of microbial interactions (both synergistic and antagonistic) occurring within these biofilms and assess their role in oral health and dental disease. METHODS PubMed database was searched for studies on microbial ecological interactions in dental biofilms. The search results did not lend themselves to systematic review and have been summarized in a narrative review instead. RESULTS Five hundred and forty-seven original research articles and 212 reviews were identified. The majority (86%) of research articles addressed bacterial-bacterial interactions, while inter-kingdom microbial interactions were the least studied. The interactions included physical and nutritional synergistic associations, antagonism, cell-to-cell communication and gene transfer. CONCLUSIONS Oral microbial communities display emergent properties that cannot be inferred from studies of single species. Individual organisms grow in environments they would not tolerate in pure culture. The networks of multiple synergistic and antagonistic interactions generate microbial inter-dependencies and give biofilms a resilience to minor environmental perturbations, and this contributes to oral health. If key environmental pressures exceed thresholds associated with health, then the competitiveness among oral microorganisms is altered and dysbiosis can occur, increasing the risk of dental disease.
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Affiliation(s)
- P D Marsh
- Department of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK
| | - Egija Zaura
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands
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Zeng L, Chen L, Burne RA. Preferred Hexoses Influence Long-Term Memory in and Induction of Lactose Catabolism by Streptococcus mutans. Appl Environ Microbiol 2018; 84:e00864-18. [PMID: 29752268 PMCID: PMC6029091 DOI: 10.1128/aem.00864-18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 04/29/2018] [Indexed: 02/05/2023] Open
Abstract
Bacteria prioritize sugar metabolism via carbohydrate catabolite repression, which regulates global gene expression to optimize the catabolism of preferred substrates. Here, we report an unusual long-term memory effect in certain Streptococcus mutans strains that alters adaptation to growth on lactose after prior exposure to glucose or fructose. In strain GS-5, cells that were first cultured on fructose and then transferred to lactose displayed an exceptionally long lag (>11 h) and slower growth compared to cells first cultured on glucose or cellobiose, which displayed a reduction in lag phase by as much as 10 h. When grown on lactose, mutants lacking the cellobiose-phosphotransferase (PTS) or phospho-β-glucosidase lost the accelerated growth associated with prior culturing on glucose. The memory effects of glucose or fructose on lactose catabolism were not as profound in strain UA159, but the lag phase was considerably shorter in mutants lacking the glucose-PTS EIIMan Interestingly, when S. mutans was cultivated on lactose, significant quantities of free glucose accumulated in the medium, with higher levels found in the cultures of strains lacking EIIMan, glucokinase, or both. Free glucose was also detected in cultures that were utilizing cellobiose or trehalose, albeit at lower levels. Such release of hexoses by S. mutans is likely of biological significance as it was found that cells required small amounts of glucose or other preferred carbohydrates to initiate efficient growth on lactose. These findings suggest that S. mutans modulates the induction of lactose utilization based on its prior exposure to glucose or fructose, which can be liberated from common disaccharides.IMPORTANCE Understanding the molecular mechanisms employed by oral bacteria to control sugar metabolism is key to developing novel therapies for management of dental caries and other oral diseases. Lactose is a naturally occurring disaccharide that is abundant in dairy products and commonly ingested by humans. However, for the dental caries pathogen Streptococcus mutans, relatively little is known about the molecular mechanisms that regulate expression of genes required for lactose uptake and catabolism. Two peculiarities of lactose utilization by S. mutans are explored here: (i) S. mutans excretes glucose that it cleaves from lactose, and (ii) prior exposure to certain carbohydrates can result in a long-term inability to use lactose. The study begins to shed light on how S. mutans may utilize bet hedging to optimize its persistence and virulence in the human oral cavity.
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Affiliation(s)
- Lin Zeng
- Department of Oral Biology, University of Florida, College of Dentistry, Gainesville, Florida, USA
| | - Lulu Chen
- Department of Oral Biology, University of Florida, College of Dentistry, Gainesville, Florida, USA
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Robert A Burne
- Department of Oral Biology, University of Florida, College of Dentistry, Gainesville, Florida, USA
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Coordinated Regulation of the EII Man and fruRKI Operons of Streptococcus mutans by Global and Fructose-Specific Pathways. Appl Environ Microbiol 2017; 83:AEM.01403-17. [PMID: 28821551 DOI: 10.1128/aem.01403-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 08/15/2017] [Indexed: 11/20/2022] Open
Abstract
The glucose/mannose-phosphotransferase system (PTS) permease EIIMan encoded by manLMN in the dental caries pathogen Streptococcus mutans has a dominant influence on sugar-specific, CcpA-independent catabolite repression (CR). Mutations in manL affect energy metabolism and virulence-associated traits, including biofilm formation, acid tolerance, and competence. Using promoter::reporter fusions, expression of the manLMN and the fruRKI operons, encoding a transcriptional regulator, a fructose-1-phosphate kinase and a fructose-PTS permease EIIFru, respectively, was monitored in response to carbohydrate source and in mutants lacking CcpA, FruR, and components of EIIMan Expression of genes for EIIMan and EIIFru was directly regulated by CcpA and CR, as evinced by in vivo and in vitro methods. Unexpectedly, not only was the fruRKI operon negatively regulated by FruR, but also so was manLMN Carbohydrate transport by EIIMan had a negative influence on expression of manLMN but not fruRKI In agreement with the proposed role of FruR in regulating these PTS operons, loss of fruR or fruK substantially altered growth on a number of carbohydrates, including fructose. RNA deep sequencing revealed profound changes in gene regulation caused by deletion of fruK or fruR Collectively, these findings demonstrate intimate interconnection of the regulation of two major PTS permeases in S. mutans and reveal novel and important contributions of fructose metabolism to global regulation of gene expression.IMPORTANCE The ability of Streptococcus mutans and other streptococcal pathogens to survive and cause human diseases is directly dependent upon their capacity to metabolize a variety of carbohydrates, including glucose and fructose. Our research reveals that metabolism of fructose has broad influences on the regulation of utilization of glucose and other sugars, and mutants with changes in certain genes involved in fructose metabolism display profoundly different abilities to grow and express virulence-related traits. Mutants lacking the FruR regulator or a particular phosphofructokinase, FruK, display changes in expression of a large number of genes encoding transcriptional regulators, enzymes required for energy metabolism, biofilm development, biosynthetic and degradative processes, and tolerance of a spectrum of environmental stressors. Since fructose is a major component of the modern human diet, the results have substantial significance in the context of oral health and the development of dental caries.
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