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Li P, Zhang Y, Chen D, Lin H. Investigation of a novel biofilm model close to the original oral microbiome. Appl Microbiol Biotechnol 2024; 108:330. [PMID: 38730049 PMCID: PMC11087337 DOI: 10.1007/s00253-024-13149-8] [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: 02/15/2023] [Revised: 01/13/2024] [Accepted: 04/16/2024] [Indexed: 05/12/2024]
Abstract
A more optimized culture medium used in vitro to mimic the bacterial composition of original oral flora as similar as possible remains difficult at present, and the goal of this study is to develop a novel oral biofilm medium to restore the original oral microbiome. Firstly, we conducted a systematic literature review by searching PubMed and summarized the current reported culture media in vitro. Seven culture media were found. We used mixed saliva as the origin of oral species to compare the effects of the above media in culturing oral multispecies biofilms. Results indicated that among the seven media brain heart infusion containing 1% sucrose (BHIs) medium, PG medium, artificial saliva (AS) medium, and SHI medium could obviously gain large oral biofilm in vitro. The nutrients contained in different culture media may be suitable for the growth of different oral bacteria; therefore, we optimized several novel media accordingly. Notably, results of crystal violet staining showed that the biofilm cultured in our modified artificial saliva (MAS) medium had the highest amount of biofilm biomass. 16S rRNA gene sequencing showed that the operational taxonomic units (OTUs) and Shannon index of biofilm cultured in MAS medium were also the highest among all the tested media. More importantly, the 16S rRNA gene sequencing analysis indicated that the biofilm cultured in MAS medium was closer to the original saliva species. Besides, biofilm cultured by MAS was denser and produced more exopolysaccharides. MAS supported stable biofilm formation on different substrata. In conclusion, this study demonstrated a novel MAS medium that could culture oral biofilm in vitro closer to the original oral microbiome, showing a good application prospect. KEY POINTS: • We compare the effects of different media in culturing oral biofilms • A novel modified artificial saliva (MAS) medium was obtained in our study • The MAS medium could culture biofilm that was closer to oral microbiome.
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Affiliation(s)
- Pengpeng Li
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China
| | - Yuwen Zhang
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China
| | - Dongru Chen
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China.
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China.
| | - Huancai Lin
- Hospital of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China.
- Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China.
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2
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Vaghasiya J, Mittal S, Choudhari SR, Rishitha N. Complete versus incomplete caries removal procedures and their effects on dental pulp in primary teeth - An in vivo study. J Indian Soc Pedod Prev Dent 2024; 42:149-155. [PMID: 38957913 DOI: 10.4103/jisppd.jisppd_116_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 05/16/2024] [Indexed: 07/04/2024] Open
Abstract
INTRODUCTION Dental caries results from an ecologic shift within the dental biofilm from a balanced population of microorganisms to an acidogenic, aciduric, and cariogenic microbiological population developed and maintained by frequent consumption of fermentable dietary carbohydrates. Total caries removal (TCR) of deep lesion may result in pulpal exposure requiring more invasive treatment. Hence, current pediatric dentistry has shifted to minimally invasive treatment that avoids more complex, time-consuming procedure, and the child's discomfort. AIM The aim of this study is to evaluate and compare clinical performance and radiographic changes after complete and incomplete caries removal procedures. MATERIALS AND METHODS The study was conducted on 60 primary molars in children aged 6-9 years. Selected 60 primary molars were randomly divided into two groups. Group 1 (PCR): infected dentin was removed, while the affected dentin was maintained on the pulpal wall. Group 2 (TCR): both infected and affected dentin were removed through low-speed carbide bur and hand excavator. Teeth were evaluated at 4 and 6 months clinically and radiographically. RESULTS The proportion was compared using Fisher's exact test. The Statistical Package for the Social Sciences version 21 was used for analysis. The level of significance was kept at 5%. CONCLUSION The clinical and radiographic success rates of ICR and CCR in primary teeth with deep carious lesions were high and did not differ significantly, indicating that the retention of carious dentin does not interfere with pulp vitality. Thus, ICR is a reliable minimally invasive approach that might replace the CCR in primary teeth when correctly indicated.
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Affiliation(s)
- Jigna Vaghasiya
- Department of Pedodontics and Preventive Dentistry, Government Dental College and Hospital, Ahmedabad, Gujarat, India
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3
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Das A, Patro S, Simnani FZ, Singh D, Sinha A, Kumari K, Rao PV, Singh S, Kaushik NK, Panda PK, Suar M, Verma SK. Biofilm modifiers: The disparity in paradigm of oral biofilm ecosystem. Biomed Pharmacother 2023; 164:114966. [PMID: 37269809 DOI: 10.1016/j.biopha.2023.114966] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 05/19/2023] [Accepted: 05/29/2023] [Indexed: 06/05/2023] Open
Abstract
A biofilm is a population of sessile microorganisms that has a distinct organized structure and characteristics like channels and projections. Good oral hygiene and reduction in the prevalence of periodontal diseases arise from minimal biofilm accumulation in the mouth, however, studies focusing on modifying the ecology of oral biofilms have not yet been consistently effective. The self-produced matrix of extracellular polymeric substances and greater antibiotic resistance make it difficult to target and eliminate biofilm infections, which lead to serious clinical consequences that are often lethal. Therefore, a better understanding is required to target and modify the ecology of biofilms in order to eradicate the infection, not only in instances of oral disorders but also in terms of nosocomial infections. The review focuses on several biofilm ecology modifiers to prevent biofilm infections, as well as the involvement of biofilm in antibiotic resistance, implants or in-dwelling device contamination, dental caries, and other periodontal disorders. It also discusses recent advances in nanotechnology that may lead to novel strategies for preventing and treating infections caused by biofilms as well as a novel outlook to infection control.
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Affiliation(s)
- Antarikshya Das
- KIIT School of Dental Sciences, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Swadheena Patro
- KIIT School of Dental Sciences, KIIT University, Bhubaneswar 751024, Odisha, India.
| | | | - Dibyangshee Singh
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Adrija Sinha
- KIIT School of Biotechnology, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Khushbu Kumari
- KIIT School of Dental Sciences, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Patnala Vedika Rao
- KIIT School of Medical Sciences, KIIT University, Bhubaneswar 751024, Odisha, India
| | - Sarita Singh
- BVG Life Sciences Limited, Sagar Complex, Old Pune-Mumbai Road, Chinchwad, Pune 411034, India
| | - Nagendra Kumar Kaushik
- Plasma Bioscience Research Center, Department of Electrical and Biological Physics, Kwangwoon University, 01897 Seoul, Republic of Korea.
| | - Pritam Kumar Panda
- Condensed Matter Theory Group, Materials Theory Division, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
| | - Mrutyunjay Suar
- KIIT School of Dental Sciences, KIIT University, Bhubaneswar 751024, Odisha, India.
| | - Suresh K Verma
- KIIT School of Dental Sciences, KIIT University, Bhubaneswar 751024, Odisha, India.
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4
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Ahirwar P, Kozlovskaya V, Nijampatnam B, Rojas EM, Pukkanasut P, Inman D, Dolmat M, Law AC, Schormann N, Deivanayagam C, Harber GJ, Michalek SM, Wu H, Kharlampieva E, Velu SE. Hydrogel-Encapsulated Biofilm Inhibitors Abrogate the Cariogenic Activity of Streptococcus mutans. J Med Chem 2023; 66:7909-7925. [PMID: 37285134 PMCID: PMC11188996 DOI: 10.1021/acs.jmedchem.3c00272] [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] [Indexed: 06/08/2023]
Abstract
We designed and synthesized analogues of a previously identified biofilm inhibitor IIIC5 to improve solubility, retain inhibitory activities, and to facilitate encapsulation into pH-responsive hydrogel microparticles. The optimized lead compound HA5 showed improved solubility of 120.09 μg/mL, inhibited Streptococcus mutans biofilm with an IC50 value of 6.42 μM, and did not affect the growth of oral commensal species up to a 15-fold higher concentration. The cocrystal structure of HA5 with GtfB catalytic domain determined at 2.35 Å resolution revealed its active site interactions. The ability of HA5 to inhibit S. mutans Gtfs and to reduce glucan production has been demonstrated. The hydrogel-encapsulated biofilm inhibitor (HEBI), generated by encapsulating HA5 in hydrogel, selectively inhibited S. mutans biofilms like HA5. Treatment of S. mutans-infected rats with HA5 or HEBI resulted in a significant reduction in buccal, sulcal, and proximal dental caries compared to untreated, infected rats.
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Affiliation(s)
- Parmanand Ahirwar
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Veronika Kozlovskaya
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | | | - Edwin M. Rojas
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- School of Dentistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Piyasuda Pukkanasut
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Daniel Inman
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Maksim Dolmat
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Anna C. Law
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Norbert Schormann
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Champion Deivanayagam
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Gregory J. Harber
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Suzanne M. Michalek
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hui Wu
- Department of Integrative Biomedical and Diagnostic Sciences, Oregon Health and Science University, Portland, OR 97239, USA
| | - Eugenia Kharlampieva
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Center of Nanoscale Materials and Biointegration, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Sadanandan E. Velu
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Microbiome Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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5
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Al Mamun AAM, Wu C, Chang C, Sanchez BC, Das A, Ton-That H. A cell wall-anchored glycoprotein confers resistance to cation stress in Actinomyces oris biofilms. Mol Oral Microbiol 2022; 37:206-217. [PMID: 35289506 PMCID: PMC9474737 DOI: 10.1111/omi.12365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/27/2022] [Accepted: 03/11/2022] [Indexed: 11/26/2022]
Abstract
Actinomyces oris plays an important role in oral biofilm development. Like many gram-positive bacteria, A. oris produces a sizable number of surface proteins that are anchored to bacterial peptidoglycan by a conserved transpeptidase named the housekeeping sortase SrtA; however, the biological role of many A. oris surface proteins in biofilm formation is largely unknown. Here, we report that the glycoprotein GspA-a genetic suppressor of srtA deletion lethality-not only promotes biofilm formation but also maintains cell membrane integrity under cation stress. In comparison to wild-type cells, under elevated concentrations of mono- and divalent cations the formation of mono- and multi-species biofilms by mutant cells devoid of gspA was significantly diminished, although planktonic growth of both cell types in the presence of cations was indistinguishable. Because gspA overexpression is lethal to cells lacking gspA and srtA, we performed a genetic screen to identify GspA determinants involving cell viability. DNA sequencing and biochemical characterizations of viable clones revealed that mutations of two critical cysteine residues and a serine residue severely affected GspA glycosylation and biofilm formation. Furthermore, mutant cells lacking gspA were markedly sensitive to sodium dodecyl sulfate, a detergent that solubilizes the cytoplasmic membranes, suggesting the cell envelope of the gspA mutant was altered. Consistent with this observation, the gspA mutant exhibited increased membrane permeability, independent of GspA glycosylation, compared to the wild-type strain. Altogether, the results support the notion that the cell wall-anchored glycoprotein GspA provides a defense mechanism against cation stress in biofilm development promoted by A. oris.
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Affiliation(s)
- Abu Amar M. Al Mamun
- Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX, USA
| | - Chenggang Wu
- Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX, USA
| | - Chungyu Chang
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Belkys C. Sanchez
- Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX, USA
- Baylor College of Medicine, Houston, TX, USA
| | - Asis Das
- Department of Medicine, Neag Comprehensive Cancer Center, University of Connecticut Health Center, Farmington, CT, USA
| | - Hung Ton-That
- Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA, USA
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, USA
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6
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Costa RC, Bertolini M, Costa Oliveira BE, Nagay BE, Dini C, Benso B, Klein MI, Barāo VAR, Souza JGS. Polymicrobial biofilms related to dental implant diseases: unravelling the critical role of extracellular biofilm matrix. Crit Rev Microbiol 2022; 49:370-390. [PMID: 35584310 DOI: 10.1080/1040841x.2022.2062219] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Biofilms are complex tri-dimensional structures that encase microbial cells in an extracellular matrix comprising self-produced polymeric substances. The matrix rich in extracellular polymeric substance (EPS) contributes to the unique features of biofilm lifestyle and structure, enhancing microbial accretion, biofilm virulence, and antimicrobial resistance. The role of the EPS matrix of biofilms growing on biotic surfaces, especially dental surfaces, is largely unravelled. To date, there is a lack of a broad overview of existing literature concerning the relationship between the EPS matrix and the dental implant environment and its role in implant-related infections. Here, we discuss recent advances in the critical role of the EPS matrix on biofilm growth and virulence on the dental implant surface and its effect on the etiopathogenesis and progression of implant-related infections. Similar to other biofilms associated with human diseases/conditions, EPS-enriched biofilms on implant surfaces promote microbial accumulation, microbiological shift, cross-kingdom interaction, antimicrobial resistance, biofilm virulence, and, consequently, peri-implant tissue damage. But intriguingly, the protagonism of EPS role on implant-related infections and the development of matrix-target therapeutic strategies has been neglected. Finally, we highlight the need for more in-depth analyses of polymicrobial interactions within EPS matrix and EPS-targeting technologies' rationale for disrupting the complex biofilm microenvironment with more outstanding translation to implant applications in the near future.
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Affiliation(s)
- Raphael C Costa
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil
| | - Martinna Bertolini
- Department of Oral Health and Diagnostic Sciences, University of Connecticut Health Center, Farmington, CT, USA
| | | | - Bruna E Nagay
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil
| | - Caroline Dini
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil
| | - Bruna Benso
- School of Dentistry, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, CA, Chile
| | - Marlise I Klein
- Department of Dental Materials and Prosthodontics, São Paulo State University, São Paulo, Brazil
| | - Valentim A R Barāo
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil
| | - Joāo Gabriel S Souza
- Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil.,Dental Science School (Faculdade de Ciências Odontológicas - FCO), Montes Claros, Brazil.,Dental Research Division, Guarulhos University, Sāo Paulo, Brazil
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7
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Intracellular glucose starvation affects gingival homeostasis and autophagy. Sci Rep 2022; 12:1230. [PMID: 35075260 PMCID: PMC8786886 DOI: 10.1038/s41598-022-05398-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 01/11/2022] [Indexed: 12/15/2022] Open
Abstract
Human gingival fibroblasts (HGnFs) maintain periodontal tissue homeostasis through active proliferation and migration. Clinically, it is considered that the wound-healing ability of the gingival tissue is maintained even in environments with insufficient supply of nutrients, such as glucose, immediately after periodontal surgery. However, the effects of such glucose-deficient environments on HGnFs remain unclear. This study aimed to investigate the effects of low-glucose environment on HGnFs homeostasis. We evaluated gingival wound healing by examining cell proliferation and migration and collagen synthesis in HGnFs cultured in 100, 50, 25, and 0 mg/dL glucose in vitro. The cellular stress levels were determined by measuring the lactate dehydrogenase (LDH) and reactive oxygen species (ROS) levels. The glucose metabolism of HGnFs in the low-glucose concentrations was studied by measuring glucose transporter type 1 (GLUT1) mRNA expression, glucose uptake assays, lactate and ATP productions. Molecular effects were examined with a focus on the LKB1-AMPK signaling pathway. Autophagy activity in glucose-deprived HGnFs was evaluated by measuring the levels of autophagy-related proteins. Low glucose levels increased cellular stress levels, autophagy activity, and enhanced glucose metabolism through the LKB1-AMPK signaling pathway, providing more ATPs to promote wound healing. Our results regarding glucose transfer suggest the rapid healing of gingival wounds.
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8
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Holguin-Loya B, Soto-Barreras U, Martinez-Martinez R, Martinez-Mata G, Sanin L, Nevarez-Rascon M, Dominguez-Perez R. Relationship between fluoride exposure and count of Streptococcus mutans in supragingival biofilm of mexican scholar children. J Dent Sci 2022; 17:211-216. [PMID: 35028040 PMCID: PMC8739274 DOI: 10.1016/j.jds.2021.04.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/16/2021] [Accepted: 04/16/2021] [Indexed: 11/19/2022] Open
Abstract
Background/purpose The use of fluoride is known to reduce the risk of dental caries. There is limited information on the relationship between Streptococcus mutans (S. mutans) and fluoride exposure. This study investigated the association between the count of S. mutans on supragingival biofilm and fluoride exposure of scholar children. Materials and methods In this cross-sectional study, 56 children from 9 to 11 years of age were selected. Fluoride concentration in drinking water, urine and saliva of each participant were assessed. The count of S. mutans was estimated by calculating the DNA copy number through a quantitative real time polymerase chain reaction (qPCR) assay. Also, sociodemographic data, oral and general health information and variables related to caries risk were evaluated. A stepwise multiple linear regression was performed in all caries related predictor variables with the count of S. mutans as the dependent variable. Results The multiple linear regression analysis showed that the concentration of fluoride in saliva (β = −3.029, p < 0.001) and urine (β = −2.057, p = 0.017), time of last visit to the dentist (β = 1.968, p = 0.001), plaque index (β = 1.637, p = 0.006) and number of surfaces with codes 3–6 (D3-6MFS) of ICDAS II criteria (β = 0.283, p = 0.076) were significantly associated with the count of S. mutans (Adjusted R square = 0.427, p < 0.001). Conclusion Fluoride levels in urine and saliva were negatively associated with the count of S. mutans in supragingival biofilm. Plaque index, D3-6MFS and time of last visit to the dentist showed a positive association.
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Affiliation(s)
- B Holguin-Loya
- Facultad de Odontología, Universidad Autónoma de Chihuahua, Chihuahua, México
| | - U Soto-Barreras
- Facultad de Odontología, Universidad Autónoma de Chihuahua, Chihuahua, México
| | - R Martinez-Martinez
- Maestría en Ciencias Odontológicas, Universidad Autónoma de San Luis Potosí, SLP, México
| | - G Martinez-Mata
- Facultad de Odontología, Universidad Autónoma de Chihuahua, Chihuahua, México
| | - L Sanin
- Facultad de Medicina, Universidad Autónoma de Chihuahua, Chihuahua, México
| | - M Nevarez-Rascon
- Facultad de Odontología, Universidad Autónoma de Chihuahua, Chihuahua, México
| | - R Dominguez-Perez
- Facultad de Medicina, Universidad Autónoma de Querétaro, Santiago de Querétaro, México
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9
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Redox Sensing Modulates the Activity of the ComE Response Regulator of Streptococcus mutans. J Bacteriol 2021; 203:e0033021. [PMID: 34516285 DOI: 10.1128/jb.00330-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus mutans, a dental pathogen, encodes the ComDE two-component system comprised of a histidine kinase (ComD) and a response regulator (ComE). This system is necessary for production of bacteriocins and development of genetic competence. ComE interacts with its cognate promoters to activate the transcription of bacteriocin and competence-related genes. Previous transcriptomic studies indicated that expressions of bacteriocin genes were upregulated in the presence of oxygen. To understand the relationship between the aerobic condition and bacteriocin expression, we analyzed the S. mutans ComE sequence and its close homologs. Surprisingly, we noticed the presence of cysteine (Cys) residues located at positions 200 and 229, which are highly conserved among the ComE homologs. Here, we investigated the role of Cys residues of S. mutans ComE in the activation of bacteriocin transcription using the PnlmA promoter that expresses bacteriocin NlmA. We constructed both single mutants and double mutants by replacing the Cys residues with serine and performed complementation assays. We observed that the presence of Cys residues is essential for PnlmA activation. With purified ComE mutant proteins, we found that ComE double mutants displayed a nearly 2-fold lower association rate than wild-type ComE. Furthermore, 1-anilinonaphthalene-8-sulfonic acid (ANS) fluorescence studies indicated that the double mutants displayed wider conformation changes than wild-type ComE. Finally, we demonstrated that close streptococcal ComE homologs successfully activate the PnlmA expression in vivo. This is the first report suggesting that S. mutans ComE and its homologs can sense the oxidation status of the cell, a phenomenon similar to the AgrA system of Staphylococcus aureus but with different outcomes. IMPORTANCE Streptococci are an important species that prefer to grow under anaerobic or microaerophilic environments. Studies have shown that streptococci growth in an aerobic environment generates oxidative stress responses by activating various defense systems, including production of antimicrobial peptides called bacteriocins. This study highlights the importance of a two-component response regulator (ComE) that senses the aerobic environment and induces bacteriocin production in Streptococcus mutans, a dental pathogen. We believe increased bacteriocin secretion under aerobic conditions is necessary for survival and colonization of S. mutans in the oral cavity by inhibiting other competing organisms. Redox sensing by response regulator might be a widespread phenomenon since two other ComE homologs from pathogenic streptococci that inhabit diverse environmental niches also perform a similar function.
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10
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Liu N, Li X, Wang M, Zhang F, Wang C, Zhang K, Wang H, Xu S, Hu W, Gu L. DexA70, the Truncated Form of a Self-Produced Dextranase, Effectively Disrupts Streptococcus mutans Biofilm. Front Microbiol 2021; 12:737458. [PMID: 34650538 PMCID: PMC8505985 DOI: 10.3389/fmicb.2021.737458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/30/2021] [Indexed: 11/30/2022] Open
Abstract
Billions of people suffer from dental caries every year in spite of the effort to reduce the prevalence over the past few decades. Streptococcus mutans is the leading member of a specific group of cariogenic bacteria that cause dental caries. S. mutans forms biofilm, which is highly resistant to harsh environment, host immunity, and antimicrobial treatments. In this study, we found that S. mutans biofilm is highly resistant to both antimicrobial agents and lysozyme. DexA70, the truncated form of DexA (amino acids 100–732), a dextranase in S. mutans, prevents S. mutans biofilm formation and disassembles existing biofilms within minutes at nanomolar concentrations when supplied exogenously. DexA70 treatment markedly enhances biofilm sensitivity to antimicrobial agents and lysozyme, indicating its great potential in combating biofilm-related dental caries.
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Affiliation(s)
- Nan Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xin Li
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Maofeng Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Fengyu Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Chuandong Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Kundi Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Hongwei Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Sujuan Xu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Wei Hu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Lichuan Gu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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11
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Lindsay EL, Faustoferri RC, Quivey RG. Repression of the TreR transcriptional regulator in Streptococcus mutans by the global regulator, CcpA. FEMS Microbiol Lett 2021; 368:6102557. [PMID: 33452880 DOI: 10.1093/femsle/fnab004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 01/13/2021] [Indexed: 11/15/2022] Open
Abstract
Streptococcus mutans, the etiologic agent of dental caries in humans, is considered a dominating force in the oral microbiome due to its highly-evolved propensity for survival. The oral pathogen encodes an elaborate array of regulatory elements, including the carbon catabolite-responsive regulator, CcpA, a global regulator key in the control of sugar metabolism and in stress tolerance response mechanisms. The recently characterized trehalose utilization operon, integral for the catabolism of the disaccharide trehalose, is controlled by a local regulator, TreR, which has been implicated in a number of cellular functions outside of trehalose catabolism. Electrophoretic mobility shift assays demonstrated that CcpA bound a putative cre site in the treR promoter. Loss of ccpA resulted in elevated expression of treR in cultures of the organism grown in glucose or trehalose, indicating that CcpA not only acts as a repressor of trehalose catabolism genes, but also the local regulator. The loss of both CcpA and TreR in S. mutans resulted in an impaired growth rate and fitness response, supporting the hypothesis that these regulators are involved in carbon catabolism control and in induction of components of the organism's stress response.
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Affiliation(s)
- E L Lindsay
- Department of Microbiology and Immunology, Box 672, University of Rochester School of Medicine and Dentistry, Rochester, 601 Elmwood Avenue, NY 14642, USA
| | - R C Faustoferri
- Center for Oral Biology, Box 611, University of Rochester School of Medicine and Dentistry, Rochester, 601 Elmwood Avenue, NY 14642, USA
| | - R G Quivey
- Department of Microbiology and Immunology, Box 672, University of Rochester School of Medicine and Dentistry, Rochester, 601 Elmwood Avenue, NY 14642, USA.,Center for Oral Biology, Box 611, University of Rochester School of Medicine and Dentistry, Rochester, 601 Elmwood Avenue, NY 14642, USA
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12
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Nijampatnam B, Ahirwar P, Pukkanasut P, Womack H, Casals L, Zhang H, Cai X, Michalek SM, Wu H, Velu SE. Discovery of Potent Inhibitors of Streptococcus mutans Biofilm with Antivirulence Activity. ACS Med Chem Lett 2021; 12:48-55. [PMID: 33488963 DOI: 10.1021/acsmedchemlett.0c00373] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/25/2020] [Indexed: 11/28/2022] Open
Abstract
Dental caries is a bacterial infectious disease characterized by demineralization of the tooth enamel. Treatment of this disease with conventional antibiotics is largely ineffective as the cariogenic bacteria form tenacious biofilms that are resistant to such treatments. The main etiological agent for dental caries is the bacterium Streptococcus mutans. S. mutans readily forms biofilms on the tooth surface and rapidly produces lactic acid from dietary sucrose. Glucosyl transferases (Gtfs) secreted by S. mutans are mainly responsible for the production of exopolysaccharides that are crucial for the biofilm architecture. Thus, inhibiting S. mutans' Gtfs is an effective approach to develop selective biofilm inhibitors that do not affect the growth of oral commensals. Herein, we report a library of 90 analogs of the previously identified lead compound, G43, and exploration of its structure activity relationships (SAR). All compounds were evaluated for the inhibition of S. mutans biofilms and bacterial growth. Selected compounds from this library were further evaluated for enzyme inhibition against Gtfs using a zymogram assay and for growth inhibition against oral commensal bacterial species such as Streptococcus gordonii and Streptococcus sanguinis. This study has led to the discovery of several new biofilm inhibitors with enhanced potency and selectivity. One of the leads, III F1 , showed marked reduction in buccal, sulcal, and proximal caries scores in a rat model of dental caries.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Hui Wu
- Department of Integrative Biomedical and Diagnostic Sciences, Oregon Health and Science University, Portland, Oregon 97239, United States
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Bayoumy EED, Abi Elhassan M, Al-Zohairy AF, Al-Awady B. Clinical and microbiological evaluation of calcium silicate versus calcium hydroxide in two-step indirect pulp treatment: A randomized clinical trial. J Int Oral Health 2021. [DOI: 10.4103/jioh.jioh_33_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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14
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Panwar H, Rokana N, Aparna SV, Kaur J, Singh A, Singh J, Singh KS, Chaudhary V, Puniya AK. Gastrointestinal stress as innate defence against microbial attack. J Appl Microbiol 2020; 130:1035-1061. [PMID: 32869386 DOI: 10.1111/jam.14836] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 08/09/2020] [Accepted: 08/21/2020] [Indexed: 12/13/2022]
Abstract
The human gastrointestinal (GI) tract has been bestowed with the most difficult task of protecting the underlying biological compartments from the resident commensal flora and the potential pathogens in transit through the GI tract. It has a unique environment in which several defence tactics are at play while maintaining homeostasis and health. The GI tract shows myriad number of environmental extremes, which includes pH variations, anaerobic conditions, nutrient limitations, elevated osmolarity etc., which puts a check to colonization and growth of nonfriendly microbial strains. The GI tract acts as a highly selective barrier/platform for ingested food and is the primary playground for balance between the resident and uninvited organisms. This review focuses on antimicrobial defense mechanisms of different sections of human GI tract. In addition, the protective mechanisms used by microbes to combat the human GI defence systems are also discussed. The ability to survive this innate defence mechanism determines the capability of probiotic or pathogen strains to confer health benefits or induce clinical events respectively.
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Affiliation(s)
- H Panwar
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - N Rokana
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - S V Aparna
- Department of Dairy Microbiology, College of Dairy Science and Technology, Kerala Veterinary and Animal Science University, Mannuthy, Thrissur, India
| | - J Kaur
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - A Singh
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - J Singh
- Department of Dairy Microbiology, College of Dairy Science and Technology, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab, India
| | - K S Singh
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - V Chaudhary
- Department of Microbiology, Punjab Agriculture University, Ludhiana, Punjab, India
| | - A K Puniya
- Dairy Microbiology Division, ICAR-National Dairy Research Institute, Karnal, Haryana, India
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15
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Dioguardi M, Quarta C, Alovisi M, Crincoli V, Aiuto R, Crippa R, Angiero F, Laneve E, Sovereto D, De Lillo A, Troiano G, Lo Muzio L. Microbial Association with Genus Actinomyces in Primary and Secondary Endodontic Lesions, Review. Antibiotics (Basel) 2020; 9:E433. [PMID: 32707891 PMCID: PMC7460180 DOI: 10.3390/antibiotics9080433] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/14/2020] [Accepted: 07/21/2020] [Indexed: 12/26/2022] Open
Abstract
The main reason for root canal treatment failure is the persistence of microorganisms after therapy, or the recontamination of the root canal system due to an inadequate seal. In the mouth, Actinomyces spp. constitute a significant part of the normal flora, which is indicative of their ability to adhere to oral tissue and resist cleansing mechanisms, such as salivary flow. This review, performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), aims to clarify the prevalence of microbial genera that are associated with the genus Actinomyces in primary and secondary endodontic infections (primary outcome), and to identify the most prevalent species of the Actinomyces genus in endodontic lesions (secondary outcome). A total of 11 studies were included in the qualitative and quantitative analysis, and a total of 331 samples were analyzed. Bacteria of the genus Actinomyces were found in 58 samples, and 46 bacterial genera were detected in association with bacteria of the genus Actinomyces. Bacteria of the genus Streptococcus and Propionibacterium were those most frequently associated with Actinomyces in the endodontic lesions considered, and Actinomyces israelii was the most frequently involved species.
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Affiliation(s)
- Mario Dioguardi
- Department of Clinical and Experimental Medicine, University of Foggia, Via Rovelli 50, 71122 Foggia, Italy; (C.Q.); (E.L.); (D.S.); (A.D.L.); (G.T.); (L.L.M.)
| | - Cristian Quarta
- Department of Clinical and Experimental Medicine, University of Foggia, Via Rovelli 50, 71122 Foggia, Italy; (C.Q.); (E.L.); (D.S.); (A.D.L.); (G.T.); (L.L.M.)
| | - Mario Alovisi
- Department of Surgical Sciences, Dental School, University of Turin, 10127 Turin, Italy;
| | - Vito Crincoli
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, Division of Complex Operating Unit of Dentistry, “Aldo Moro” University of Bari, Piazza G. Cesare 11, 70124 Bari, Italy;
| | - Riccardo Aiuto
- Department of Biomedical, Surgical, and Dental Science, University of Milan, 20122 Milan, Italy;
| | - Rolando Crippa
- Department of Oral Pathology, Italian Stomatological Institute, 20122 Milan, Italy;
| | - Francesca Angiero
- Department of Medical Sciences and Diagnostic Integrated, S. Martino Hospital, University of Genova, 16132 Genova, Italy;
| | - Enrica Laneve
- Department of Clinical and Experimental Medicine, University of Foggia, Via Rovelli 50, 71122 Foggia, Italy; (C.Q.); (E.L.); (D.S.); (A.D.L.); (G.T.); (L.L.M.)
| | - Diego Sovereto
- Department of Clinical and Experimental Medicine, University of Foggia, Via Rovelli 50, 71122 Foggia, Italy; (C.Q.); (E.L.); (D.S.); (A.D.L.); (G.T.); (L.L.M.)
| | - Alfredo De Lillo
- Department of Clinical and Experimental Medicine, University of Foggia, Via Rovelli 50, 71122 Foggia, Italy; (C.Q.); (E.L.); (D.S.); (A.D.L.); (G.T.); (L.L.M.)
| | - Giuseppe Troiano
- Department of Clinical and Experimental Medicine, University of Foggia, Via Rovelli 50, 71122 Foggia, Italy; (C.Q.); (E.L.); (D.S.); (A.D.L.); (G.T.); (L.L.M.)
| | - Lorenzo Lo Muzio
- Department of Clinical and Experimental Medicine, University of Foggia, Via Rovelli 50, 71122 Foggia, Italy; (C.Q.); (E.L.); (D.S.); (A.D.L.); (G.T.); (L.L.M.)
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16
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Damé-Teixeira N, Parolo CCF, Malz M, Devine DA, DO T. Gene expression profile of Scardovia spp. in the metatranscriptome of root caries. Braz Oral Res 2020; 34:e042. [PMID: 32401932 DOI: 10.1590/1807-3107bor-2020.vol34.0042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/16/2020] [Indexed: 11/22/2022] Open
Abstract
A few investigations of caries biofilms have identified Scardovia spp.; however, little is known about its involvement in caries pathogenesis. The purpose of this study was to assess the gene expression profile of Scardovia spp. in root caries, and compare it with other microorganisms. Clinical samples from active root caries lesions were collected. Microbial mRNA was isolated and cDNA sequenced. The function and composition of the Scardovia were investigated using two methods: a) de novo assembly of the read data and mapping to contigs, and b) reads mapping to reference genomes. Pearson correlation was performed (p < 0.05). Proportion of Scardovia inopinata and Scardovia wiggsiae sequences ranged from 0-6% in the root caries metatranscriptome. There was a positive correlation between the transcriptome of Lactobacillus spp. and Scardovia spp. (r = 0.70; p = 0.03), as well as with other Bifidobacteriaceae (r = 0.91; p = 0.0006). Genes that code for fructose 6-phosphate phosphoketolase (the key enzyme for "Bifid shunt"), as well as ABC transporters and glycosyl-hydrolases were highly expressed. In conclusion, "Bifid shunt" and starch metabolism are involved in carbohydrate metabolism of S. inopinata and S. wiggsiae in root caries. There is a positive correlation between the metabolism abundance of Lactobacillus spp., Bifidobacteriaceae members, and Scardovia in root caries.
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Affiliation(s)
- Naile Damé-Teixeira
- Universidade de Brasília - UnB, Faculty of Heath Sciences, Department of Dentistry, Brasília, DF, Brazil
| | - Clarissa Cavalcanti Fatturi Parolo
- Univeridade Federal do Rio Grande do Sul - UFRGS, Faculty of Dentistry, Department of Social and Preventive Dentistry, Porto Alegre, RS, Brazil
| | - Marisa Malz
- Univeridade Federal do Rio Grande do Sul - UFRGS, Faculty of Dentistry, Department of Social and Preventive Dentistry, Porto Alegre, RS, Brazil
| | - Deirdre Ann Devine
- University of Leeds, School of Dentistry, Division of Oral Biology, Leeds, England
| | - Thuy DO
- University of Leeds, School of Dentistry, Division of Oral Biology, Leeds, England
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Duanis-Assaf D, Kenan E, Sionov R, Steinberg D, Shemesh M. Proteolytic Activity of Bacillus subtilis upon κ-Casein Undermines Its "Caries-Safe" Effect. Microorganisms 2020; 8:microorganisms8020221. [PMID: 32041335 PMCID: PMC7074799 DOI: 10.3390/microorganisms8020221] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 01/28/2020] [Accepted: 02/04/2020] [Indexed: 02/06/2023] Open
Abstract
Milk is believed to be a relatively “caries-safe” food. This belief relies on the fact that caseins, which constitute around 80% of milk’s protein content, were found to inhibit the adhesion of Streptococcus mutans to enamel and, therefore, decrease biofilm formation. While S. mutans is considered a leading cause of dental disorders, Bacillus subtilis is a non-pathogenic foodborne bacterium, frequently contaminating milk and its products. This study aimed to investigate the effects of dairy-associated foodborne bacteria such as B. subtilis on biofilm formation by S. mutans in the presence of casein proteins. Our results indicate that there is a significant decrease in total biofilm formation by S. mutans exposed to a casein protein mixture in a mono-species culture, whereas, in the co-culture with B. subtilis, an inhibitory effect of the caseins mixture on S. mutans biofilm formation was observed. Proteolytic activity analysis suggested that B. subtilis is capable of breaking down milk proteins, especially κ-casein, which enables biofilm formation by S. mutans in the presence of milk caseins. Therefore, these findings may challenge the assumption that milk is “caries-safe”, especially in a complex microbial environment.
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Affiliation(s)
- Danielle Duanis-Assaf
- Department of Food Sciences, Institute for Postharvest Technology and Food Sciences, Agricultural Research Organization (ARO), Volcani Center, Rishon LeZion 7505101, Israel;
- Biofilm Research Laboratory, Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem 9112001, Israel; (E.K.); (R.S.); (D.S.)
| | - Eli Kenan
- Biofilm Research Laboratory, Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem 9112001, Israel; (E.K.); (R.S.); (D.S.)
| | - Ronit Sionov
- Biofilm Research Laboratory, Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem 9112001, Israel; (E.K.); (R.S.); (D.S.)
| | - Doron Steinberg
- Biofilm Research Laboratory, Institute of Dental Sciences, Faculty of Dental Medicine, Hebrew University-Hadassah, Jerusalem 9112001, Israel; (E.K.); (R.S.); (D.S.)
| | - Moshe Shemesh
- Department of Food Sciences, Institute for Postharvest Technology and Food Sciences, Agricultural Research Organization (ARO), Volcani Center, Rishon LeZion 7505101, Israel;
- Correspondence: ; Tel.: +972-3-968-3868
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18
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Transcriptomic Analysis of Aggregatibacter actinomycetemcomitans Core and Accessory Genes in Different Growth Conditions. Pathogens 2019; 8:pathogens8040282. [PMID: 31816971 PMCID: PMC6963384 DOI: 10.3390/pathogens8040282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 11/21/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans genome can be divided into an accessory gene pool (found in some but not all strains) and a core gene pool (found in all strains). The functions of the accessory genes (genomic islands and non-island accessory genes) are largely unknown. We hypothesize that accessory genes confer critical functions for A. actinomycetemcomitans in vivo. This study examined the expression patterns of accessory and core genes of A. actinomycetemcomitans in distinct growth conditions. We found similar expression patterns of island and non-island accessory genes, which were generally lower than the core genes in all growth conditions. The median expression levels of genomic islands were 29%–37% of the core genes in enriched medium but elevated to as high as 63% of the core genes in nutrient-limited media. Several putative virulence genes, including the cytolethal distending toxin operon, were found to be activated in nutrient-limited conditions. In conclusion, genomic islands and non-island accessory genes exhibited distinct patterns of expression from the core genes and may play a role in the survival of A. actinomycetemcomitans in nutrient-limited environments.
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Katalinić I, Budimir A, Bošnjak Z, Jakovljević S, Anić I. The photo-activated and photo-thermal effect of the 445/970 nm diode laser on the mixed biofilm inside root canals of human teeth in vitro: A pilot study. Photodiagnosis Photodyn Ther 2019; 26:277-283. [DOI: 10.1016/j.pdpdt.2019.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 03/26/2019] [Accepted: 04/12/2019] [Indexed: 12/19/2022]
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20
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Figueiredo JAPD, Machado AM, Oliveira VPD, Hartmann R, Waltrick SBG, Borba MGD, Brew MC, Estrela CRDA, Böttcher DE. Dendritic cells and their relation to apical peridontitis. Braz Oral Res 2018; 32:e71. [PMID: 30365612 DOI: 10.1590/1807-3107bor-2018.vol32.0071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2018] [Accepted: 06/07/2018] [Indexed: 02/03/2023] Open
Abstract
The purpose of this manuscript was to re-discuss apical periodontitis, apical biofilm, and its possible relationship with dendritic cells (DC). DCs are potent regulators of the immune system and their function is divided into three categories that involve the presentation of antigens: the presentation of antigens and activation of T cells; a not well established category suggested that DCs induce and maintain immunological tolerance; and the maintenance of the immune memory in conjunction with B cells. DCs in periapical inflammatory lesions are composed of at least two subpopulations that can be distinguished on the basis of ultrastructure and phenotype. These populations might differ in lineage, state of maturation, differentiation, activation, and/or function. The authors hereby analyzed the root apexes of teeth under SEM, after performing apicoectomy due to the failure of conventional endodontic treatment. Microbial biofilm with multispecies and areas of resorption with the presence of Howship lacunae, and images suggestive of denditric cells could be observed. The presence of DCs in periapical lesion could be an indication of the severity of the lesion, with a constant presence of antigen in the periradicular region.
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Affiliation(s)
- José Antonio Poli de Figueiredo
- Universidade Federal do Rio Grande do Sul - UFRGS, School of Dentistry, Department of Morphological Sciences, Porto Alegre, RS, Brazil
| | - Audrey Moraes Machado
- Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS, School of Dentistry, Clinical Department, Porto Alegre, RS, Brazil
| | - Vinícius Pasqualotti de Oliveira
- Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS, School of Dentistry, Clinical Department, Porto Alegre, RS, Brazil
| | - Rafael Hartmann
- Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS, School of Dentistry, Clinical Department, Porto Alegre, RS, Brazil
| | | | - Maristela Gutierrez de Borba
- Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS, School of Dentistry, Clinical Department, Porto Alegre, RS, Brazil
| | | | | | - Daiana Elisabeth Böttcher
- Pontifícia Universidade Católica do Rio Grande do Sul - PUCRS, School of Dentistry, Clinical Department, Porto Alegre, RS, Brazil
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21
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Characterization of the Trehalose Utilization Operon in Streptococcus mutans Reveals that the TreR Transcriptional Regulator Is Involved in Stress Response Pathways and Toxin Production. J Bacteriol 2018; 200:JB.00057-18. [PMID: 29632089 DOI: 10.1128/jb.00057-18] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/30/2018] [Indexed: 11/20/2022] Open
Abstract
Streptococcus mutans, the organism most frequently associated with the development of dental caries, is able to utilize a diverse array of carbohydrates for energy metabolism. One such molecule is trehalose, a disaccharide common in human foods, which has been recently implicated in enhancing the virulence of epidemic strains of the pathogen Clostridium difficile In this study, mutants with deletions of all three genes in the putative S. mutans trehalose utilization operon were characterized, and the genes were shown to be required for wild-type levels of growth when trehalose was the only carbohydrate source provided. Interestingly, the TreR transcriptional regulator appeared to be critical for responding to oxidative stress and for mounting a protective stress tolerance response following growth at moderately acidic pH. mRNA sequencing (RNA-seq) of a treR deletion mutant suggested that in S. mutans, TreR acts as a trehalose-sensing activator of transcription of the tre operon, rather than as a repressor, as described in other species. In addition, deletion of treR caused the downregulation of a number of genes involved in genetic competence and bacteriocin production, supporting the results of a recent study linking trehalose and the S. mutans competence pathways. Finally, deletion of treR compromised the ability of S. mutans to inhibit the growth of the competing species Streptococcus gordonii and Lactococcus lactis Taking the results together, this study solidifies the role of the S. mutans tre operon in trehalose utilization and suggests novel functions for the TreR regulator, including roles in the stress response and competitive fitness.IMPORTANCES. mutans is the primary etiologic agent of dental caries, which globally is the most common chronic disease. S. mutans must be able to outcompete commensal organisms in its dental plaque niche in order to establish persistence and pathogenesis. To that end, S. mutans metabolizes a diverse array of carbohydrates to generate acid and impede its acid-sensitive neighbors. Additionally, S. mutans utilizes quorum signaling through genetic competence-associated pathways to induce production of toxins to kill its rivals. This study definitively shows that the S. mutans trehalose utilization operon is required for growth in trehalose. Furthermore, this study suggests that the S. mutans TreR transcriptional regulator has a novel role in virulence through regulation of genes involved in genetic competence and toxin production.
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Sreenivasan PK, Prasad KV. Distribution of dental plaque and gingivitis within the dental arches. J Int Med Res 2017; 45:1585-1596. [PMID: 28795618 PMCID: PMC5718714 DOI: 10.1177/0300060517705476] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 05/27/2017] [Indexed: 11/21/2022] Open
Abstract
Objective The natural accumulation of supragingival plaque on surfaces of human teeth is associated with gingival inflammation and the initiation of common oral diseases. This study evaluated the distribution of dental plaque and gingivitis scores within the dental arches after prophylaxis. Methods Adult subjects from the Dharwad, India area representing the general population who provided written informed consent were scheduled for screening. Healthy subjects over the age of 18 years, not currently requiring any medical or dental care, and presenting with a complement of at least 20 natural teeth were recruited for this parallel design study. Enrolled subjects (n = 41) underwent oral examinations for dental plaque (PI) and gingivitis (GI) using the Turesky modification of the Quigley-Hein and the Löe-Silness Index, respectively, at the baseline visit, followed by a whole mouth dental prophylaxis. Subjects were given fluoride toothpaste for twice daily oral hygiene for the next 30 days. Subjects were recalled on days 15 and 30 for PI and GI examinations identical to baseline. Results Analyses indicated that mean scores for PI and GI on either arch and the whole mouth were higher than 2 and 1, respectively, during all examinations. Anterior surfaces consistently exhibited lower PI scores than posterior regions of either arch, or the entire dentition. Regional GI differences within the dentition were similar to PI scores, with lower scores on anterior than posterior teeth. Prophylaxis reduced both the frequency and mean scores of both PI and GI, irrespective of arch, with lower scores observed on anterior than posterior regions during all recall visits. Molar and lingual regions consistently exhibited higher PI and GI scores compared with anterior surfaces. At all examinations, mean scores for both plaque and gingivitis were higher on approximal vestibular than mid-vestibular surfaces. Conclusions Differences observed in PI and GI within the dentition have several practical implications: (a) there are advantages of whole mouth assessments for oral health (b) a need for oral hygiene formulations to reduce the larger deposits of dental plaque in the posterior region and resultant gingival inflammation, and
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Affiliation(s)
| | - Kakarla V.V. Prasad
- Department of Community Dentistry, SDM College of Dental Sciences, Dharwad, India
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KESKİN E, BAĞLAR S. ACID TOLERANCE RESPONCE OF CARIOGENIC MICROORGANISMS AND MALOLACTIC FERMENTATION. CUMHURIYET DENTAL JOURNAL 2017. [DOI: 10.7126/cumudj.345960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Senneby A, Davies JR, Svensäter G, Neilands J. Acid tolerance properties of dental biofilms in vivo. BMC Microbiol 2017; 17:165. [PMID: 28743239 PMCID: PMC5525231 DOI: 10.1186/s12866-017-1074-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 07/17/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The ecological plaque hypothesis explains caries development as the result of the enrichment of acid tolerant bacteria in dental biofilms in response to prolonged periods of low pH. Acid production by an acid tolerant microflora causes demineralisation of tooth enamel and thus, individuals with a greater proportion of acid tolerant bacteria would be expected to be more prone to caries development. Biofilm acid tolerance could therefore be a possible biomarker for caries prediction. However, little is known about the stability of biofilm acid tolerance over time in vivo or the distribution throughout the oral cavity. Therefore the aim of this study was to assess intra-individual differences in biofilm acid-tolerance between different tooth surfaces and inter-individual variation as well as stability of acid tolerance over time. RESULTS The majority of the adolescents showed low scores for biofilm acid tolerance. In 14 of 20 individuals no differences were seen between the three tooth sites examined. In the remaining six, acid-tolerance at the premolar site differed from one of the other sites. At 51 of 60 tooth sites, acid-tolerance at baseline was unchanged after 1 month. However, acid tolerance values changed over a 1-year period in 50% of the individuals. CONCLUSIONS Biofilm acid tolerance showed short-term stability and low variation between different sites in the same individual suggesting that the acid tolerance could be a promising biological biomarker candidate for caries prediction. Further evaluation is however needed and prospective clinical trials are called for to evaluate the diagnostic accuracy.
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Affiliation(s)
- A Senneby
- Department of Oral and Maxillofacial Radiology, Malmö University, Faculty of Odontology, 205 06, Malmö, SE, Sweden
| | - J R Davies
- Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - G Svensäter
- Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden
| | - J Neilands
- Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden.
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Suzuki Y, Nagasawa R, Senpuku H. Inhibiting effects of fructanase on competence-stimulating peptide-dependent quorum sensing system in Streptococcus mutans. J Infect Chemother 2017; 23:634-641. [PMID: 28729051 DOI: 10.1016/j.jiac.2017.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 05/22/2017] [Accepted: 06/16/2017] [Indexed: 11/28/2022]
Abstract
Streptococcus mutans produces glucosyltransferases encoded by the gtfB and gtfC genes, which synthesize insoluble glucan, and both insoluble and soluble glucans by conversion of sucrose, and are known as principal agents to provide strong biofilm formation and demineralization on tooth surfaces. S. mutans possess a Com-dependent quorum sensing (QS) system, which is important for survival in severe conditions. The QS system is stimulated by the interaction between ComD {Receptor to competence-stimulating peptide (CSP)} encoded by the comD and CSP encoded by the comC, and importantly associated with bacteriocin production and genetic competence. Previously, we found enzyme fructanase (FruA) as a new inhibitor for the glucan-dependent biofilm formation. In the present study, inhibiting effects by FruA on glucan-independent biofilm formation of S. mutans UA159, UA159.gtfB-, UA159.gtfC-, and UA159.gtfBC- were observed in sucrose and no sucrose sugars-supplemented conditions using the plate assay. The reduction of UA159.comC- and UA159.comD- biofilm formation were also observed as compared with UA159 in same conditions. These results suggested that inhibitions of glucan-independent and Com-dependent biofilm formation were involved in the inhibiting mechanism by FruA. To more thoroughly investigate effects by FruA on the QS system, we examined on CSP-stimulated and Com-dependent bacteriocin production and genetic transformation. FruA inhibited bacteriocin production in collaboration with CSP and genetic transformation in bacterial cell conditions treated with FruA. Our findings show that FruA has multiple effects that inhibit survival functions of S. mutans, including biofilm formation and CSP-dependent QS responses, indicating its potential use as an agent for prevention of dental caries.
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Affiliation(s)
- Yusuke Suzuki
- Department of Maxillofacial Surgery, Nihon University Graduate School of Dentistry at Matsudo, Chiba, Japan; Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ryo Nagasawa
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hidenobu Senpuku
- Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
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Biofilm extracellular polysaccharides degradation during starvation and enamel demineralization. PLoS One 2017; 12:e0181168. [PMID: 28715508 PMCID: PMC5513492 DOI: 10.1371/journal.pone.0181168] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 06/27/2017] [Indexed: 01/20/2023] Open
Abstract
This study was conducted to evaluate if extracellular polysaccharides (EPS) are used by Streptococcus mutans (Sm) biofilm during night starvation, contributing to enamel demineralization increasing occurred during daily sugar exposure. Sm biofilms were formed during 5 days on bovine enamel slabs of known surface hardness (SH). The biofilms were exposed to sucrose 10% or glucose + fructose 10.5% (carbohydrates that differ on EPS formation), 8x/day but were maintained in starvation during the night. Biofilm samples were harvested during two moments, on the end of the 4th day and in the morning of the 5th day, conditions of sugar abundance and starvation, respectively. The slabs were also collected to evaluate the percentage of surface hardness loss (%SHL). The biofilms were analyzed for EPS soluble and insoluble and intracellular polysaccharides (IPS), viable bacteria (CFU), biofilm architecture and biomass. pH, calcium and acid concentration were determined in the culture medium. The data were analyzed by two-way ANOVA followed by Tukey's test or Student's t-test. The effect of the factor carbohydrate treatment for polysaccharide analysis was significant (p < 0.05) but not the harvest moment (p > 0.05). Larger amounts of soluble and insoluble EPS and IPS were formed in the sucrose group when compared to glucose + fructose group (p < 0.05), but they were not metabolized during starvation time (S-EPS, p = 0.93; I-EPS, p = 0.11; and IPS = 0.96). Greater enamel %SHL was also found for the sucrose group (p < 0.05) but the demineralization did not increase during starvation (p = 0.09). In conclusion, the findings suggest that EPS metabolization by S. mutans during night starvation do not contribute to increase enamel demineralization occurred during the daily abundance of sugar.
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Kim CH, Lee ES, Kang SM, de Josselin de Jong E, Kim BI. Bactericidal effect of the photocatalystic reaction of titanium dioxide using visible wavelengths on Streptococcus mutans biofilm. Photodiagnosis Photodyn Ther 2017; 18:279-283. [DOI: 10.1016/j.pdpdt.2017.03.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 02/17/2017] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
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Abstract
The oral ecosystem comprises the oral flora, so-called oral microbiome, the different anatomic microniches of the oral cavity, and its bathing fluid, saliva. The oral microbiome comprises a group of organisms and includes bacteria, archaea, fungi, protozoa, and viruses. The oral microbiome exists suspended in saliva as planktonic phase organisms or attached to oral surfaces as a plaque biofilm. Homeostasis of the plaque biofilm and its symbiotic relationship with the host is critical for oral health. Disequilibrium or dysbiosis within the plaque biofilms is the initiating event that leads to major oral diseases, such as caries and periodontal disease.
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Affiliation(s)
- Lakshman Samaranayake
- Faculty of Dentistry, University of Hong Kong, The Deanery, Floor 7, 34, Hospital Road, Hong Kong, China; University of Queensland, Brisbane, Australia.
| | - Victor H Matsubara
- Department of Oral Microbiology, School of Dentistry, University of São Paulo, Av Professor Lineu Prestes, 2227, São Paulo 05508-000, Brazil
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Understanding the Streptococcus mutans Cid/Lrg System through CidB Function. Appl Environ Microbiol 2016; 82:6189-6203. [PMID: 27520814 DOI: 10.1128/aem.01499-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 08/05/2016] [Indexed: 01/09/2023] Open
Abstract
The Streptococcus mutans lrgAB and cidAB operons have been previously described as a potential model system to dissect the complexity of biofilm development and virulence of S. mutans Herein, we have attempted to further characterize the Cid/Lrg system by focusing on CidB, which has been shown to be critical for the ability of S. mutans to survive and persist in a nonpreferred oxygen-enriched condition. We have found that the expression level of cidB is critical to oxidative stress tolerance of S. mutans, most likely by impacting lrg expression. Intriguingly, the impaired aerobic growth phenotype of the cidB mutant could be restored by the additional loss of either CidA or LrgA. Growth-dependent expression of cid and lrg was demonstrated to be tightly under the control of both CcpA and the VicKR two-component system (TCS), regulators known to play an essential role in controlling major catabolic pathways and cell envelope homeostasis, respectively. RNA sequencing (RNA-Seq) analysis revealed that mutation of cidB resulted in global gene expression changes, comprising major domains of central metabolism and virulence processes, particularly in those involved with oxidative stress resistance. Loss of CidB also significantly changed the expression of genes related to genomic islands (GI) TnSmu1 and TnSmu2, the CRISPR (clustered regularly interspaced short palindromic repeats)-Cas system, and toxin-antitoxin (T/A) modules. Taken together, these data show that CidB impinges on the stress response, as well as the fundamental cellular physiology of S. mutans, and further suggest a potential link between Cid/Lrg-mediated cellular processes, S. mutans pathogenicity, and possible programmed growth arrest and cell death mechanisms. IMPORTANCE The ability of Streptococcus mutans to survive a variety of harmful or stressful conditions and to emerge as a numerically significant member of stable oral biofilm communities are essential elements for its persistence and cariogenicity. In this study, the homologous cidAB and lrgAB operons, previously identified as being highly balanced and coordinated during S. mutans aerobic growth, were further characterized through the functional and transcriptomic analysis of CidB. Precise control of CidB levels is shown to impact the expression of lrg, oxidative stress tolerance, major metabolic domains, and the molecular modules linked to cell death and lysis. This study advances our understanding of the Cid/Lrg system as a key player in the integration of complex environmental signals (such as oxidative stress) into the regulatory networks that modulate S. mutans virulence and cell homeostasis.
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Abstract
Lactic acid bacteria (LAB) are important starter, commensal, or pathogenic microorganisms. The stress physiology of LAB has been studied in depth for over 2 decades, fueled mostly by the technological implications of LAB robustness in the food industry. Survival of probiotic LAB in the host and the potential relatedness of LAB virulence to their stress resilience have intensified interest in the field. Thus, a wealth of information concerning stress responses exists today for strains as diverse as starter (e.g., Lactococcus lactis), probiotic (e.g., several Lactobacillus spp.), and pathogenic (e.g., Enterococcus and Streptococcus spp.) LAB. Here we present the state of the art for LAB stress behavior. We describe the multitude of stresses that LAB are confronted with, and we present the experimental context used to study the stress responses of LAB, focusing on adaptation, habituation, and cross-protection as well as on self-induced multistress resistance in stationary phase, biofilms, and dormancy. We also consider stress responses at the population and single-cell levels. Subsequently, we concentrate on the stress defense mechanisms that have been reported to date, grouping them according to their direct participation in preserving cell energy, defending macromolecules, and protecting the cell envelope. Stress-induced responses of probiotic LAB and commensal/pathogenic LAB are highlighted separately due to the complexity of the peculiar multistress conditions to which these bacteria are subjected in their hosts. Induction of prophages under environmental stresses is then discussed. Finally, we present systems-based strategies to characterize the "stressome" of LAB and to engineer new food-related and probiotic LAB with improved stress tolerance.
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Nie M, Chen D, Gao Z, Wu X, Li T. Natural Immunoreactivity of Secretory IgA to Indigenous Strains of Streptococcus mutans From Chinese Spousal Pairs. Jundishapur J Microbiol 2016; 9:e24662. [PMID: 27303613 PMCID: PMC4902851 DOI: 10.5812/jjm.24662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 01/09/2016] [Indexed: 11/16/2022] Open
Abstract
Background Dental caries is a well-known biofilm-mediated disease initiated by Streptococcus mutans, which should infect and colonize in a milieu perfused with components of the mucosal immune system. Little is known, however, regarding the relationship between the natural secretory IgA activity and S. mutans of a variety of diverse genotypes. Objectives The current study aimed to use spousal pairs to investigate the natural immunoreactivity of salivary secretory IgA to different genotype strains of S. mutans. Patients and Methods Indigenous strains were characterized from nine spousal pairs using polymerase reaction chain (PCR) and arbitrarily primed polymerase chain reaction (AP-PCR) by genotype monitoring. Unstimulated submandibular/sublingual secretions were collected and the concentrations of secretory IgA were determined by the enzyme-linked immunosorbent assay (ELISA). Each saliva sample was examined by Western blot to analyze the immunoreactivity of naturally occurring salivary secretory IgA antibodies for his/her own indigenous strain, spouse’s strain and reference strains including S. mutans GS-5 and Ingbritt (C). Results The results showed that naturally induced salivary IgA antibodies against S. mutans were present in all subjects. Almost all subjects had the similar individual immunoblotting profiles to different genotype strains. Conclusions The current study indicated that the immunoreactivity of secretory IgA might have no direct correlation with the colonization of indigenous flora and rejection of exogenous strains in adults. The relationship of microbes, host and dental caries should be in the light of coevolved microecosystem as a whole, but not caused by one factor alone.
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Affiliation(s)
- Min Nie
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine (Wuhan University), Ministry of Education, Wuhan, China
- Corresponding author: Min Nie, The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine (Wuhan University), Ministry of Education, Wuhan, China. Tel: +86-2787686102, Fax: +86-2787647443, E-mail:
| | - Dong Chen
- Department of Implantology, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Zhenyan Gao
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine (Wuhan University), Ministry of Education, Wuhan, China
| | - Xinyu Wu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine (Wuhan University), Ministry of Education, Wuhan, China
| | - Tong Li
- The State Key Laboratory Breeding Base of Basic Science of Stomatology, Hubei Province and Key Laboratory of Oral Biomedicine (Wuhan University), Ministry of Education, Wuhan, China
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Mohammadi Z, Jafarzadeh H, Shalavi S. Antimicrobial efficacy of chlorhexidine as a root canal irrigant: a literature review. J Oral Sci 2016; 56:99-103. [PMID: 24930745 DOI: 10.2334/josnusd.56.99] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Use of an appropriate root canal irrigant is essential during endodontic treatment, due to the complex and unpredictable anatomy of the root canal system and limitations in the mechanical instrumentation techniques used to obtain a clean, bacteria-free canal. Several irrigants, such as sodium hypochlorite, chlorhexidine, hydrogen peroxide, and normal saline, have been proposed as canal system irrigants in endodontic treatment. The widely used endodontic irrigant chlorhexidine is a positively charged lipophilic/hydrophobic molecule that interacts with phospholipids and lipopolysaccharides on the bacterial cell membrane. In endodontics, its mode of antibacterial activity is determined by its concentration (0.2% or 2%). This article reviews findings from available endodontic studies on the antibacterial, antifungal, and antibiofilm activities of chlorhexidine.
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Affiliation(s)
- Zahed Mohammadi
- Iranian Center for Endodontic Research, Shahid Beheshti University of Medical Sciences
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Kawarai T, Narisawa N, Suzuki Y, Nagasawa R, Senpuku H. Streptococcus mutans biofilm formation is dependent on extracellular DNA in primary low pH conditions. J Oral Biosci 2016. [DOI: 10.1016/j.job.2015.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Singhal DK, Acharya S, Thakur AS. Microbiological analysis after complete or partial removal of carious dentin using two different techniques in primary teeth: A randomized clinical trial. Dent Res J (Isfahan) 2016; 13:30-7. [PMID: 26962313 PMCID: PMC4770467 DOI: 10.4103/1735-3327.174695] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Background: The management of deep carious lesions can be done by various techniques but residual caries dilemma still persists and bacterial reduction in cavities treated by either partial or complete caries removal techniques is debatable. So the objective of the present randomized clinical trial was to compare microbial counts in cavities submitted to complete caries removal and partial caries removal using either hand instruments or burs before and after 3 weeks of restoration. Materials and Methods: Primary molars with acute carious lesions in inner half of dentine and vital pulp were randomly divided into three groups of 14 each: Group A: Partial caries removal using hand instruments atraumatic restorative treatment (ART) only; Group B: Partial caries removal using bur; Group C: Complete caries removal using bur and caries detector dye. Dentine sample obtained after caries removal and 3 weeks after restoration, were subjected to microbial culture and counting (colony-forming units [CFU]/mg of dentine) for total viable bacterial count, Streptococcus spp., mutans streptococci, Lactobacillus spp. Results: Three techniques of caries removal showed significant (P < 0.05) reduction in all microorganisms studied after 3 weeks of evaluation, but there was no statistically significant difference in percentage reduction of microbial count among three groups. Conclusion: Results suggest the use of partial caries removal in a single session as compared to complete caries removal as a part of treatment of deep lesions in deciduous teeth in order to reduce the risk of pulp exposure. Partial caries removal using ART can be preferred for community settings as public health procedure for caries management.
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Affiliation(s)
- Deepak Kumar Singhal
- Department of Public Health Dentistry, Manipal College of Dental Sciences, Manipal, Manipal University, Karnataka, India
| | - Shashidhar Acharya
- Department of Public Health Dentistry, Manipal College of Dental Sciences, Manipal, Manipal University, Karnataka, India
| | - Arun Singh Thakur
- Department of Public Health Dentistry, Government Dental College, Shimla, Himachal Pradesh, India
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Dige I, Baelum V, Nyvad B, Schlafer S. Monitoring of extracellular pH in young dental biofilms grown in vivo in the presence and absence of sucrose. J Oral Microbiol 2016; 8:30390. [PMID: 26894480 PMCID: PMC4759832 DOI: 10.3402/jom.v8.30390] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/18/2016] [Accepted: 01/19/2016] [Indexed: 02/01/2023] Open
Abstract
Background and objective pH in dental biofilms is of central importance for the development of caries. We used the ratiometric pH-sensitive dye C-SNARF-4 in combination with digital image analysis to monitor extracellular pH in dental biofilms grown in situ with and without sucrose supply. Design Dental biofilms (48 h) from 10 individuals were collected on glass slabs mounted on intra-oral appliances. During growth, appliances were immersed extra-orally in either physiological saline or 4% sucrose for 2 min, eight times per day. Fluorescence emissions of C-SNARF-4 in deep layers of the biofilms were recorded ex vivo with confocal microscopy for 15 min or for 1 h after exposure to 0.4% glucose. Extracellular pH was determined ratiometrically using digital image analysis. Results Extracellular pH dropped rapidly in most examined sites after addition of glucose. Distinct pH microenvironments were observed within single biofilms. The variation in pH was similar between sites within the same biofilm and sites from different individuals. pH drop patterns did not differ between biofilms exposed to sucrose-free and sucrose-rich environments. Conclusion The present study is the first of its kind to apply the combination of pH ratiometry and digital image analysis to systematically record extracellular pH in intact dental biofilms from several individuals for up to 1 h. We observed highly heterogeneous pH landscapes and the presence of acidogenic microenvironments – ‘acidogenic hotspots’ – within the biofilms. The data suggest that pH drops in young (48 h) dental biofilms are independent of the sucrose supply during growth.
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Affiliation(s)
- Irene Dige
- Department of Dentistry, HEALTH, Aarhus University, Aarhus, Denmark;
| | - Vibeke Baelum
- Department of Dentistry, HEALTH, Aarhus University, Aarhus, Denmark
| | - Bente Nyvad
- Department of Dentistry, HEALTH, Aarhus University, Aarhus, Denmark
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Photodynamic Antimicrobial Chemotherapy for Root Canal System Asepsis: A Narrative Literature Review. Int J Dent 2015; 2015:269205. [PMID: 26783392 PMCID: PMC4689923 DOI: 10.1155/2015/269205] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 10/08/2015] [Accepted: 11/04/2015] [Indexed: 11/17/2022] Open
Abstract
Aim. The aim of this comprehensive literature review was to address the question: Does photodynamic therapy (PDT) improve root canal disinfection through significant bacterial reduction in the root canal system? Methodology. A comprehensive narrative literature review was performed to compare PDT effect with sodium hypochlorite as the comparative classical irrigant. Two reviewers independently conducted literature searches using a combination of medical subject heading terms and key words to identify relevant studies comparing information found in 7 electronic databases from January 2000 to May 2015. A manual search was performed on bibliography of articles collected on electronic databases. Authors were contacted to ask for references of more research not detected on the prior electronic and manual searches. Results. The literature search provided 62 titles and abstracts, from which 29 studies were related directly to the search theme. Considering all publications, 14 (48%) showed PDT to be more efficient in antimicrobial outcome than NaOCl (0.5-6% concentration) used alone and 2 (7%) revealed similar effects between them. Toluidine blue and methylene blue are the most used photosensitizers and most commonly laser has 660 nm of wavelength with a 400 nm diameter of intracanal fiber. Conclusions. PDT has been used without a well-defined protocol and still remains at an experimental stage waiting for further optimization. The level of evidence available in clinical studies to answer this question is low and at high risk of bias.
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Loss of NADH Oxidase Activity in Streptococcus mutans Leads to Rex-Mediated Overcompensation in NAD+ Regeneration by Lactate Dehydrogenase. J Bacteriol 2015; 197:3645-57. [PMID: 26350138 DOI: 10.1128/jb.00383-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 09/02/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Previous studies of the oral pathogen Streptococcus mutans have determined that this Gram-positive facultative anaerobe mounts robust responses to both acid and oxidative stresses. The water-forming NADH oxidase (Nox; encoded by nox) is thought to be critical for the regeneration of NAD(+), for use in glycolysis, and for the reduction of oxygen, thereby preventing the formation of damaging reactive oxygen species. In this study, the free NAD(+)/NADH ratio in a nox deletion strain (Δnox) was discovered to be remarkably higher than that in the parent strain, UA159, when the strains were grown in continuous culture. This unanticipated result was explained by significantly elevated lactate dehydrogenase (Ldh; encoded by ldh) activity and ldh transcription in the Δnox strain, which was mediated in part by the redox-sensing regulator Rex. cDNA microarray analysis of S. mutans cultures exposed to simultaneous acid stress (growth at a low pH) and oxidative stress (generated through the deletion of nox or the addition of exogenous oxygen) revealed a stress response synergistically heightened over that with either stress alone. In the Δnox strain, this elevated stress response included increased glucose phosphoenolpyruvate phosphotransferase system (PTS) activity, which appeared to be due to elevated manL transcription, mediated in part, like elevated ldh transcription, by Rex. While the Δnox strain does possess a membrane composition different from that of the parent strain, it did not appear to have defects in either membrane permeability or ATPase activity. However, the altered transcriptome and metabolome of the Δnox strain were sufficient to impair its ability to compete with commensal peroxigenic oral streptococci during growth under aerobic conditions. IMPORTANCE Streptococcus mutans is an oral pathogen whose ability to outcompete commensal oral streptococci is strongly linked to the formation of dental caries. Previous work has demonstrated that the S. mutans water-forming NADH oxidase is critical for both carbon metabolism and the prevention of oxidative stress. The results of this study show that upregulation of lactate dehydrogenase, mediated through the redox sensor Rex, overcompensates for the loss of nox. Additionally, nox deletion led to the upregulation of mannose and glucose transport, also mediated through Rex. Importantly, the loss of nox rendered S. mutans defective in its ability to compete directly with two species of commensal streptococci, suggesting a role for nox in the pathogenic potential of this organism.
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Morphological and proteomic analyses of the biofilms generated by Streptococcus mutans isolated from caries-active and caries-free adults. J Dent Sci 2015. [DOI: 10.1016/j.jds.2014.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Abstract
Endodontic disease is a biofilm-mediated infection, and primary aim in the management of endodontic disease is the elimination of bacterial biofilm from the root canal system. The most common endodontic infection is caused by the surface-associated growth of microorganisms. It is important to apply the biofilm concept to endodontic microbiology to understand the pathogenic potential of the root canal microbiota as well as to form the basis for new approaches for disinfection. It is foremost to understand how the biofilm formed by root canal bacteria resists endodontic treatment measures. Bacterial etiology has been confirmed for common oral diseases such as caries and periodontal and endodontic infections. Bacteria causing these diseases are organized in biofilm structures, which are complex microbial communities composed of a great variety of bacteria with different ecological requirements and pathogenic potential. The biofilm community not only gives bacteria effective protection against the host's defense system but also makes them more resistant to a variety of disinfecting agents used as oral hygiene products or in the treatment of infections. Successful treatment of these diseases depends on biofilm removal as well as effective killing of biofilm bacteria. So, the fundamental to maintain oral health and prevent dental caries, gingivitis, and periodontitis is to control the oral biofilms. From these aspects, the formation of biofilms carries particular clinical significance because not only host defense mechanisms but also therapeutic efforts including chemical and mechanical antimicrobial treatment measures have the most difficult task of dealing with organisms that are gathered in a biofilm. The aim of this article was to review the mechanisms of biofilms’ formation, their roles in pulpal and periapical pathosis, the different types of biofilms, the factors influencing biofilm formation, the mechanisms of their antimicrobial resistance, techniques to identify biofilms.
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Affiliation(s)
- Kapil Jhajharia
- Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Melaka Manipal Medical College, Melaka, Malaysia
| | - Abhishek Parolia
- Department of Restorative Dentistry, Faculty of Dentistry, International Medical University, Kuala Lumpur, Malaysia
| | - K Vikram Shetty
- Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Melaka Manipal Medical College, Melaka, Malaysia
| | - Lata Kiran Mehta
- Department of Pedodontics and Preventive Dentistry, P. D. M. Dental College and Research Institute, Jhajjar, Haryana, India
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Hasan S, Danishuddin M, Khan AU. Inhibitory effect of zingiber officinale towards Streptococcus mutans virulence and caries development: in vitro and in vivo studies. BMC Microbiol 2015; 15:1. [PMID: 25591663 PMCID: PMC4316655 DOI: 10.1186/s12866-014-0320-5] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 12/11/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Streptococcus mutans is known as a key causative agent of dental caries. It metabolizes dietary carbohydrate to produce acids which reduce the environmental pH leading to tooth demineralization. The ability of this bacterium to tolerate acids coupled with acid production, allows its effective colonization in the oral cavity leading to the establishment of highly cariogenic plaque. For this reason, S. mutans is the only bacterium found in significantly higher numbers than other bacteria in the dental plaque. The aim of this study was to evaluate the effect of crude extract and methanolic fraction of Z. officinale against S. mutans virulence properties. RESULTS We investigated in vitro and in vivo activity of crude extract and methanolic fraction at sub- MIC levels against cariogenic properties of S. mutans. We found that these extracts strongly inhibited a variety of virulence properties which are critical for its pathogenesis. The biofilm formation in S. mutans was found to be reduced during critical growth phases. Furthermore, the glucan synthesis and adherence was also found to be inhibited. Nevertheless, the insoluble glucan synthesis and sucrose dependent adherence were apparently more reduced as compared to soluble glucan synthesis and sucrose- independent adherence. Biofilm architecture inspected with the help of confocal and scanning electron microscopy, showed dispersion of cells in the treated group as compared to the control. The Quantitative Real Time PCR (qRT-PCR) data had shown the down regulation of the virulence genes, which is believed to be one of the major reasons responsible for the observed reduction in the virulence properties. The incredible reduction of caries development was found in treated group of rats as compared to the untreated group which further validate our in vitro data. CONCLUSION The whole study concludes a prospective role of crude extract and methanolic fraction of Z. officinale in targeting complete array of cariogenic properties of S. mutans, thus reducing its pathogenesis. Hence, it may be strongly proposed as a putative anti- cariogenic agent.
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Affiliation(s)
- Sadaf Hasan
- Medical Microbiology and Molecular Biology lab. Interdisciplinary Biotechnology Unit, Aligarh Muslim University, 202002, Aligarh, India.
| | - Mohd Danishuddin
- Medical Microbiology and Molecular Biology lab. Interdisciplinary Biotechnology Unit, Aligarh Muslim University, 202002, Aligarh, India.
| | - Asad U Khan
- Medical Microbiology and Molecular Biology lab. Interdisciplinary Biotechnology Unit, Aligarh Muslim University, 202002, Aligarh, India.
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Effect of Nanosilver Gel, Chlorhexidine Gluconate, and Camphorated Phenol on Enterococcus faecalis Biofilm. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:380278. [PMID: 27355067 PMCID: PMC4897455 DOI: 10.1155/2014/380278] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 07/25/2014] [Accepted: 07/25/2014] [Indexed: 11/18/2022]
Abstract
Aim. To assess the effectiveness of nanosilver gel (NSG) in comparison to chlorhexidine gluconate (CHX) and camphorated phenol (CP) against Enterococcus faecalis (E.f) biofilm. Methods and Materials. Two tests were done, methyl thiazolyl tetrazolium (MTT) assay and confocal laser scanning microscopy (CLSM) analysis, to determine the effectiveness of NSG, CHX, and CP on E.f biofilm. Polystyrene microtiter 96- and 6-well plates were used for MTT and CLSM, respectively. Nanosilver gel was in three concentrations (0.05%, 0.1%, and 0.2%), chlorhexidine gluconate used was 2%, and camphorated phenol and normal saline were as control. Analysis was done using one-way ANOVA; the post hoc test was run for multiple comparisons. The level of statistical significance was set at P < 0.05. Results. One-way ANOVA showed significant differences among groups (0.05% NSG and CP, 0.1% NSG and CP, 0.2% NSG and CP, 0.1% NSG and 2% CHX, 0.2% and NSG and 2% CHX) (P < 0.001) and also showed significant difference between groups (P < 0.001), f-ratio 87.823. A post hoc Tukey's test revealed no significant difference between chlorhexidine gluconate and 0.05% nanosilver gel (P > 0.05). Conclusions. 0.1% and 0.2% nanosilver gel is more effective on Enterococcus faecalis biofilm as compared to chlorhexidine gluconate and camphorated phenol.
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Streptococcus mutans NADH oxidase lies at the intersection of overlapping regulons controlled by oxygen and NAD+ levels. J Bacteriol 2014; 196:2166-77. [PMID: 24682329 DOI: 10.1128/jb.01542-14] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
NADH oxidase (Nox, encoded by nox) is a flavin-containing enzyme used by the oral pathogen Streptococcus mutans to reduce diatomic oxygen to water while oxidizing NADH to NAD(+). The critical nature of Nox is 2-fold: it serves to regenerate NAD(+), a carbon cycle metabolite, and to reduce intracellular oxygen, preventing formation of destructive reactive oxygen species (ROS). As oxygen and NAD(+) have been shown to modulate the activity of the global transcription factors Spx and Rex, respectively, Nox is potentially poised at a critical junction of two stress regulons. In this study, microarray data showed that either addition of oxygen or loss of nox resulted in altered expression of genes involved in energy metabolism and transport and the upregulation of genes encoding ROS-metabolizing enzymes. Loss of nox also resulted in upregulation of several genes encoding transcription factors and signaling molecules, including the redox-sensing regulator gene rex. Characterization of the nox promoter revealed that nox was regulated by oxygen, through SpxA, and by Rex. These data suggest a regulatory loop in which the roles of nox in reduction of oxygen and regeneration of NAD(+) affect the activity levels of Spx and Rex, respectively, and their regulons, which control several genes, including nox, crucial to growth of S. mutans under conditions of oxidative stress.
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Evaluation of subgingival microflora in all ceramic restorations with subgingival heavy chamfer finish lines. J Indian Prosthodont Soc 2014; 13:19-23. [PMID: 24431702 DOI: 10.1007/s13191-012-0165-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 07/19/2012] [Indexed: 10/28/2022] Open
Abstract
Microbial colonization in the gingival sulci of abutment teeth receiving all ceramic retainers with subgingival margins need to be studied to assess the prognosis of periodontal health, which determine the eventual success of fixed partial dentures. This prospective observational study was done to evaluate the quantitative alteration in the microbial flora in the gingival sulci of abutment teeth adjacent to the edentulous space prior and after receiving all ceramic retainers over varying time intervals of 1 week, 1 month and 2 months respectively. Twenty, healthy partially edentulous patients, aged 20-50 years with single missing central incisor were selected for this prospective observational study and their microbial samples were collected from the gingival sulci of abutments adjacent to edentulous space with sterile paper points and cultured and the estimated values for microflora served as controls. The same abutments were prepared to receive all ceramic retainers with subgingival heavy chamfer marginal finish lines. The patients were recalled after 1 week, 1 month, 2 months intervals during which the collected subgingival microbial samples were cultured and the corresponding quantitative microbial alteration in the restored gingival sulci was recorded. The obtained data was statistically analysed using the student t test and repeated analysis of variance test. The results of the study inferred student t test expressed a statistically significant (p < 0.001) progressive increase in gingival sulcular microbial colonisation in the abutment teeth before [M = 2.52 ± SD 1.21(10(6)) CFU/ml] and after receiving all ceramic retainers over varying time intervals of 1 week [M = 3.25 ± SD 1.21(10(6)) CFU/ml], 1 month [M = 4.64 ± SD 1.13(10(6)) CFU/ml] and 2 months [M = 4.75 ± SD 1.16(10(6)) CFU/ml] respectively. The result of repeated analysis of variance test inferred that there was a statistically significant difference (p < 0.001) in the subgingival microfloral count between the pre operative and post operative samples at 1 week, 1 month and 2 months. Subgingivally placed all-ceramic retainers with heavy chamfer finish lines in the abutment teeth demonstrated a statistically significant increase in sulcular microbial colonization over varying time intervals of 1 week, 1 month and 2 months respectively and this may affect periodontal health of abutment teeth progressively.
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Netuschil L, Auschill TM, Sculean A, Arweiler NB. Confusion over live/dead stainings for the detection of vital microorganisms in oral biofilms--which stain is suitable? BMC Oral Health 2014; 14:2. [PMID: 24410850 PMCID: PMC3898065 DOI: 10.1186/1472-6831-14-2] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 12/27/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There is confusion over the definition of the term "viability state(s)" of microorganisms. "Viability staining" or "vital staining techniques" are used to distinguish live from dead bacteria. These stainings, first established on planctonic bacteria, may have serious shortcomings when applied to multispecies biofilms. Results of staining techniques should be compared with appropriate microbiological data. DISCUSSION Many terms describe "vitality states" of microorganisms, however, several of them are misleading. Authors define "viable" as "capable to grow". Accordingly, staining methods are substitutes, since no staining can prove viability.The reliability of a commercial "viability" staining assay (Molecular Probes) is discussed based on the corresponding product information sheet: (I) Staining principle; (II) Concentrations of bacteria; (III) Calculation of live/dead proportions in vitro. Results of the "viability" kit are dependent on the stains' concentration and on their relation to the number of bacteria in the test. Generally this staining system is not suitable for multispecies biofilms, thus incorrect statements have been published by users of this technique.To compare the results of the staining with bacterial parameters appropriate techniques should be selected. The assessment of Colony Forming Units is insufficient, rather the calculation of Plating Efficiency is necessary. Vital fluorescence staining with Fluorescein Diacetate and Ethidium Bromide seems to be the best proven and suitable method in biofilm research.Regarding the mutagenicity of staining components users should be aware that not only Ethidium Bromide might be harmful, but also a variety of other substances of which the toxicity and mutagenicity is not reported. SUMMARY - The nomenclature regarding "viability" and "vitality" should be used carefully.- The manual of the commercial "viability" kit itself points out that the kit is not suitable for natural multispecies biofilm research, as supported by an array of literature.- Results obtained with various stains are influenced by the relationship between bacterial counts and the amount of stain used in the test. Corresponding vitality data are prone to artificial shifting.- As microbiological parameter the Plating Efficiency should be used for comparison.- Ethidium Bromide is mutagenic. Researchers should be aware that alternative staining compounds may also be or even are mutagenic.
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Affiliation(s)
- Lutz Netuschil
- Department of Periodontology, Dental School, Philipps-University Marburg, Marburg, Germany.
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Waters MS, Kundu S, Lin NJ, Lin-Gibson S. Microstructure and mechanical properties of in situ Streptococcus mutans biofilms. ACS APPLIED MATERIALS & INTERFACES 2014; 6:327-332. [PMID: 24351115 DOI: 10.1021/am404344h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Insight into live microbial biofilm microstructure and mechanical properties and their interactions with the underlying substrate can lead to the development of new remedial strategies and/or materials. Here we report mechanical properties of dental pathogenic Streptococcus mutans biofilms, grown on a polystyrene-coated plate of a shear rheometer in physiologically relevant conditions, precisely controlled in a custom built bioreactor. In situ measurements demonstrated the importance of microstructure and composition of extracellular polymeric substances on the biofilm modulus. The biofilms behave like a weak gel with storage moduli higher than loss moduli. The simple but robust experimental technique presented here can easily be extended to other biofilm-material systems.
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Affiliation(s)
- Michael S Waters
- Material Measurement Laboratory, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
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Effect of Modified Nonequilibrium Plasma with Chlorhexidine Digluconate against Endodontic Biofilms In Vitro. J Endod 2013; 39:1438-43. [DOI: 10.1016/j.joen.2013.06.027] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 06/04/2013] [Accepted: 06/10/2013] [Indexed: 02/05/2023]
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Abstract
Bacteria in the biofilm mode of growth are protected against chemical and mechanical stresses. Biofilms are composed, for the most part, of extracellular polymeric substances (EPSs). The extracellular matrix is composed of different chemical constituents, such as proteins, polysaccharides, and extracellular DNA (eDNA). Here we aimed to identify the roles of different matrix constituents in the viscoelastic response of biofilms. Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, and Pseudomonas aeruginosa biofilms were grown under different conditions yielding distinct matrix chemistries. Next, biofilms were subjected to mechanical deformation and stress relaxation was monitored over time. A Maxwell model possessing an average of four elements for an individual biofilm was used to fit the data. Maxwell elements were defined by a relaxation time constant and their relative importance. Relaxation time constants varied widely over the 104 biofilms included and were divided into seven ranges (<1, 1 to 5, 5 to 10, 10 to 50, 50 to 100, 100 to 500, and >500 s). Principal-component analysis was carried out to eliminate related time constant ranges, yielding three principal components that could be related to the known matrix chemistries. The fastest relaxation component (<3 s) was due to the presence of water and soluble polysaccharides, combined with the absence of bacteria, i.e., the heaviest masses in a biofilm. An intermediate component (3 to 70 s) was related to other EPSs, while a distinguishable role was assigned to intact eDNA, which possesses a unique principal component with a time constant range (10 to 25 s) between those of EPS constituents. This implies that eDNA modulates its interaction with other matrix constituents to control its contribution to viscoelastic relaxation under mechanical stress. The protection offered by biofilms to organisms that inhabit it against chemical and mechanical stresses is due in part to its matrix of extracellular polymeric substances (EPSs) in which biofilm organisms embed themselves. Mechanical stresses lead to deformation and possible detachment of biofilm organisms, and hence, rearrangement processes occur in a biofilm to relieve it from these stresses. Maxwell analysis of stress relaxation allows the determination of characteristic relaxation time constants, but the biofilm components and matrix constituents associated with different stress relaxation processes have never been identified. Here we grew biofilms with different matrix constituents and used principal-component analysis to reveal that the presence of water and soluble polysaccharides, together with the absence of bacteria, is associated with the fastest relaxation, while other EPSs control a second, slower relaxation. Extracellular DNA, as a matrix constituent, had a distinguishable role with its own unique principal component in stress relaxation with a time constant range between those of other EPSs.
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Rezende TMB, Lima SMF, Petriz BA, Silva ON, Freire MS, Franco OL. Dentistry proteomics: From laboratory development to clinical practice. J Cell Physiol 2013; 228:2271-84. [DOI: 10.1002/jcp.24410] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Accepted: 05/21/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Taia M. B. Rezende
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
- Curso de Odontologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
| | - Stella M. F. Lima
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
- Curso de Odontologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
| | - Bernardo A. Petriz
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
| | - Osmar N. Silva
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
| | - Mirna S. Freire
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
| | - Octávio L. Franco
- Centro de Análises Proteômicas e Bioquímicas, Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia; Universidade Católica de Brasília; Brasília Distrito Federal Brazil
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Gorynia S, Koban I, Matthes R, Welk A, Gorynia S, Hübner NO, Kocher T, Kramer A. In vitro efficacy of cold atmospheric pressure plasma on S. sanguinis biofilms in comparison of two test models. GMS HYGIENE AND INFECTION CONTROL 2013; 8:Doc01. [PMID: 23967387 PMCID: PMC3746598 DOI: 10.3205/dgkh000201] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dental plaque critically affects the etiology of caries, periodontitis and periimplantitis. The mechanical removal of plaque can only be performed partially due to limited accessibility. Therefore, plaque still represents one of the major therapeutic challenges. Even though antiseptic mouth rinses reduce the extent of biofilm temporarily, plaque removal remains incomplete and continuous usage can even result in side effects. Here we tested argon plasma produced by kinpen09 as one option to inactivate microorganisms and to eliminate plaque. S. sanguinis biofilms cultivated in either the European Biofilm Reactor (EUREBI) or in 24 well plates were treated with argon plasma. In both test systems a homogeneous, good analyzable and stable biofilm was produced on the surface of titan plates within 72 h (>6,9 log10 CFU/ml). Despite the significantly more powerful biofilm production in EUREBI, the difference of 0.4 log10 CFU/ml between EUREBI and the 24 well plates was practically not relevant. For that reason both test models were equally qualified for the analysis of efficacy of cold atmospheric pressure plasma. We demonstrate a significant reduction of the biofilm compared to the control in both test models. After plasma application of 180 s the biofilm produced in EUREBI or in 24 well plates was decreased by 0.6 log10 CFU/ml or 0.5 log10 CFU/ml, respectively. In comparison to recently published studies analyzing the efficacy of kinpen09, S. sanguinis produces a hardly removable biofilm. Future investigations using reduced distances between plasma source and biofilm, various compositions of plasma and alternative plasma sources will contribute to further optimization of the efficacy against S. sanguinis biofilms.
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Affiliation(s)
- Susanne Gorynia
- Institute of Hygiene and Environmental Medicine, University Medicine Greifswald, Ernst-Moritz-Arndt University, Greifswald, Germany
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Abstract
Conventional antibacterial treatment fails to eradicate biofilms associated with common infections of the oral cavity. Unlike chemical agents, which are less effective than anticipated, owing to diffusion limitations in biofilms, light is more effective on bacteria in biofilm than in suspension. Effectiveness depends also on the type and parameters of the light. We tested the phototoxic effects of non-coherent blue light (wavelengths, 400-500 nm) and CO(2) laser (wavelength, 10.6 μm), which have different mechanisms of action on the oral bacterium Streptoccocus mutans, in biofilm and on tooth enamel. Exposure of S. mutans in biofilm to blue light had a delayed effect on bacterial viability throughout the biofilm and a sustained antibacterial effect on biofilm newly formed by previously irradiated bacteria. A synergistic antibacterial effect between blue light and H(2)O(2) may enhance the phototoxic effect, which involves a photochemical mechanism mediated by reactive oxygen species (ROS) formation. The effect of CO(2) laser irradiation on the viability of S. mutans in biofilm on enamel samples appeared to be higher in the deep layers, due to heating of the enamel surface by the absorbed energy. Biofilms do not interfere with the chemical changes resulting from irradiation, which may increase the enamel's resistance to acid attack.
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Affiliation(s)
- O Feuerstein
- Department of Prosthodontics, The Hebrew University-Hadassah School of Dental Medicine, P.O.B. 12272, Jerusalem 91120, Israel.
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