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Nairn BL, Lima BP, Chen R, Yang JQ, Wei G, Chumber AK, Herzberg MC. Effects of fluid shear stress on oral biofilm formation and composition and the transcriptional response of Streptococcus gordonii. Mol Oral Microbiol 2024. [PMID: 39158270 DOI: 10.1111/omi.12481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 06/19/2024] [Accepted: 07/23/2024] [Indexed: 08/20/2024]
Abstract
Biofilms are subjected to many environmental pressures that can influence community structure and physiology. In the oral cavity, and many other environments, biofilms are exposed to forces generated by fluid flow; however, our understanding of how oral biofilms respond to these forces remains limited. In this study, we developed a linear rocker model of fluid flow to study the impact of shear forces on Streptococcus gordonii and dental plaque-derived multispecies biofilms. We observed that as shear forces increased, S. gordonii biofilm biomass decreased. Reduced biomass was largely independent of overall bacterial growth. Transcriptome analysis of S. gordonii biofilms exposed to moderate levels of shear stress uncovered numerous genes with differential expression under shear. We also evaluated an ex vivo plaque biofilm exposed to fluid shear forces. Like S. gordonii, the plaque biofilm displayed decreased biomass as shear forces increased. Examination of plaque community composition revealed decreased diversity and compositional changes in the plaque biofilm exposed to shear. These studies help to elucidate the impact of fluid shear on oral bacteria and may be extended to other bacterial biofilm systems.
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Affiliation(s)
- Brittany L Nairn
- Department of Biological Sciences, Bethel University, St. Paul, Minnesota, USA
| | - Bruno P Lima
- Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ruoqiong Chen
- Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Judy Q Yang
- Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Guanju Wei
- Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, Minnesota, USA
- Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ashwani K Chumber
- Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, USA
| | - Mark C Herzberg
- Department of Diagnostic and Biological Sciences, University of Minnesota, Minneapolis, Minnesota, USA
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2
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Montoya C, Baraniya D, Chen T, Al-Hebshi NN, Orrego S. The effect of dental material type and masticatory forces on periodontitis-derived subgingival microbiomes. Biofilm 2024; 7:100199. [PMID: 38800100 PMCID: PMC11127099 DOI: 10.1016/j.bioflm.2024.100199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 04/19/2024] [Accepted: 05/04/2024] [Indexed: 05/29/2024] Open
Abstract
Restorative dental materials can frequently extend below the gingival margin, serving as a potential haven for microbial colonization, and altering the local oral microbiome to ignite infection. However, the contribution of dental materials on driving changes of the composition of the subgingival microbiome is under-investigated. This study evaluated the microbiome-modulating properties of three biomaterials, namely resin dental composites (COM), antimicrobial piezoelectric composites (BTO), and hydroxyapatite (HA), using an optimized in vitro subgingival microbiome model derived from patients with periodontal disease. Dental materials were subjected to static or cyclic loading (mastication forces) during biofilm growth. Microbiome composition was assessed by 16S rRNA gene sequencing. Dysbiosis was measured in terms of subgingival microbial dysbiosis index (SMDI). Biomaterials subjected to cyclic masticatory loads were associated with enhanced biofilm viability except on the antibacterial composite. Biomaterials held static were associated with increased biofilm biomass, especially on HA surfaces. Overall, the microbiome richness (Chao index) was similar for all the biomaterials and loading conditions. However, the microbiome diversity (Shannon index) for the HA beams was significantly different than both composites. In addition, beta diversity analysis revealed significant differences between composites and HA biomaterials, and between both loading conditions (static and cyclic). Under static conditions, microbiomes formed over HA surfaces resulted in increased dysbiosis compared to composites through the enrichment of periopathogens, including Porphyromonas gingivalis, Porphyromonas endodontalis, and Fretibacterium spp., and depletion of commensals such as Granulicatella and Streptococcus spp. Interestingly, cyclic loading reversed the dysbiosis of microbiomes formed over HA (depletion of periopathogenes) but increased the dysbiosis of microbiomes formed over composites (enrichment of Porphyromonas gingivalis and Fusobacterim nucleatum). Comparison of species formed on both composites (control and antibacterial) showed some differences. Commercial composites enriched Selenomonas spp. and depleted Campylobacter concisus. Piezoelectric composites effectively controlled the microbiome viability without significantly impacting the species abundance. Findings of this work open new understandings of the effects of different biomaterials on the modulation of oral biofilms and the relationship with oral subgingival infections.
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Affiliation(s)
- Carolina Montoya
- Smart Biomaterials Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Divyashri Baraniya
- Oral Microbiome Research Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Tsute Chen
- Department of Microbiology, Forsyth Institute, Cambridge, MA, USA
| | - Nezar Noor Al-Hebshi
- Oral Microbiome Research Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
| | - Santiago Orrego
- Smart Biomaterials Laboratory, Department of Oral Health Sciences, Kornberg School of Dentistry, Temple University, Philadelphia, PA, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA, USA
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3
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Ramachandra SS, Wright P, Han P, Abdal‐hay A, Lee RSB, Ivanovski S. Evaluating models and assessment techniques for understanding oral biofilm complexity. Microbiologyopen 2023; 12:e1377. [PMID: 37642488 PMCID: PMC10464519 DOI: 10.1002/mbo3.1377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/07/2023] [Accepted: 08/17/2023] [Indexed: 08/31/2023] Open
Abstract
Oral biofilms are three-dimensional (3D) complex entities initiating dental diseases and have been evaluated extensively in the scientific literature using several biofilm models and assessment techniques. The list of biofilm models and assessment techniques may overwhelm a novice biofilm researcher. This narrative review aims to summarize the existing literature on biofilm models and assessment techniques, providing additional information on selecting an appropriate model and corresponding assessment techniques, which may be useful as a guide to the beginner biofilm investigator and as a refresher to experienced researchers. The review addresses previously established 2D models, outlining their advantages and limitations based on the growth environment, availability of nutrients, and the number of bacterial species, while also exploring novel 3D biofilm models. The growth of biofilms on clinically relevant 3D models, particularly melt electrowritten fibrous scaffolds, is discussed with a specific focus that has not been previously reported. Relevant studies on validated oral microcosm models that have recently gaining prominence are summarized. The review analyses the advantages and limitations of biofilm assessment methods, including colony forming unit culture, crystal violet, 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt assays, confocal microscopy, fluorescence in situ hybridization, scanning electron microscopy, quantitative polymerase chain reaction, and next-generation sequencing. The use of more complex models with advanced assessment methodologies, subject to the availability of equipment/facilities, may help in developing clinically relevant biofilms and answering appropriate research questions.
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Affiliation(s)
- Srinivas Sulugodu Ramachandra
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- Preventive Dental Sciences, College of DentistryGulf Medical UniversityAjmanUnited Arab Emirates
| | - Patricia Wright
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
| | - Pingping Han
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
| | - Abdalla Abdal‐hay
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- Department of Engineering Materials and Mechanical Design, Faculty of EngineeringSouth Valley UniversityQenaEgypt
- Faculty of Industry and Energy Technology, Mechatronics Technology ProgramNew Cairo Technological University, New Cairo‐Fifth SettlementCairoEgypt
| | - Ryan S. B. Lee
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
| | - Saso Ivanovski
- Centre for Orofacial Regeneration, Rehabilitation and Reconstruction (COR3), School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
- School of Dentistry, Faculty of Health and Behavioural SciencesThe University of QueenslandBrisbaneAustralia
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4
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Ramachandra SS, Abdal-Hay A, Han P, Lee RSB, Ivanovski S. Fabrication and characterization of a 3D polymicrobial microcosm biofilm model using melt electrowritten scaffolds. BIOMATERIALS ADVANCES 2023; 145:213251. [PMID: 36580768 DOI: 10.1016/j.bioadv.2022.213251] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 11/19/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
The majority of current biofilm models or substrates are two-dimensional (2D) and support biofilm growth in the horizontal plane only. Three-dimensional (3D) substrates may support both horizontal and vertical biofilm growth. This study compared biofilm growth quantity and quality between highly porous 3D micrometric fibrous scaffolds and 2D film substrates fabricated from medical grade polycaprolactone (mPCL). Melt electrowriting (MEW), a high-resolution additive manufacturing technology, was employed to design orderly aligned fine (~12 μm) fibre-based 3D scaffolds, while 2D films were fabricated by a casting method. The 3D scaffolds with a controlled pore size of 100 and 250 μm and thickness of ~0.8 mm and 2D films were incubated in pooled saliva collected from six volunteers for 1, 2, 4, 7 and 10 days at 37 °C to facilitate polymicrobial biofilm formation. Crystal violet assay demonstrated greater biofilm biomass in 3D MEW scaffolds than in 2D films. Biofilm thickness in 3D scaffolds was significantly higher compared to the biofilm thickness in 2D films. Both biovolume and substratum coverage of the biofilms was higher in the 3D scaffolds compared to 2D films. Polymeric bridges, pores, and channels characteristic of biofilms could be demonstrated by scanning electron microscopy. 16S rRNA sequencing demonstrated that the polymicrobial biofilms in the 3D scaffolds were able to retain 60-70 % of the original inoculum microbiome after 4 days. The MEW-fabricated 3D fibrous scaffold is a promising substrate for supporting multidirectional biofilm growth and modelling of a polymicrobial microcosm.
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Affiliation(s)
- Srinivas Sulugodu Ramachandra
- School of Dentistry, Centre of Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), The University of Queensland, Brisbane, Australia; Department of Preventive Dental Sciences, College of Dentistry, Gulf Medical University, Ajman, United Arab Emirates
| | - Abdalla Abdal-Hay
- School of Dentistry, Centre of Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), The University of Queensland, Brisbane, Australia; Department of Engineering Materials and Mechanical Design, Faculty of Engineering, South Valley University, Qena, Egypt; Faculty of Industry and Energy Technology, Mechatronics Technology Program, New Cairo Technological University, New Cairo - Fifth Settlement, Cairo, Egypt
| | - Pingping Han
- School of Dentistry, Centre of Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), The University of Queensland, Brisbane, Australia
| | - Ryan S B Lee
- School of Dentistry, Centre of Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), The University of Queensland, Brisbane, Australia
| | - Sašo Ivanovski
- School of Dentistry, Centre of Orofacial Regeneration, Reconstruction and Rehabilitation (COR3), The University of Queensland, Brisbane, Australia.
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5
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Abstract
Microbial communities are eubiotic ecosystems that interact dynamically and synergistically with the human body. Imbalances in these interactions may cause dysbiosis by enhancing the occurrence of inflammatory conditions, such as periodontal or inflammatory bowel diseases. However, the mechanisms that lie behind eubiosis-dysbiosis transitions are still unclear and constantly being redefined. While the societal impact of these diseases is steadily increasing, the lack of a clear understanding behind the onset of the inflammatory conditions prevents the proper clinical strategies from being formulated. Although preclinical and clinical models and short-term planar in vitro cultures represent superb research tools, they are still lacking human relevance and long-term use. Bioreactors and organs-on-a-chip have attracted interest because of their ability to recreate and sustain the physical, structural, and mechanical features of the native environment, as well as to support long-term coculture of mammalian cells and the microbiome through modulation of pH and oxygen gradients. Existing devices, however, are still under development to sustain the microbiome-host coculture over long periods of time. In this scenario, to understand disease triggers and develop therapeutics, research efforts should command the development of three-dimensional constructs that would allow the investigation of processes underlying the microbial community assembly and how microorganisms influence host traits in both acute and chronic conditions.
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Affiliation(s)
- Miryam Adelfio
- University of Massachusetts-Lowell, Department of Biomedical Engineering, One University Avenue, Lowell, Massachusetts 01854, United States
| | - Chiara Elia Ghezzi
- University of Massachusetts-Lowell, Department of Biomedical Engineering, One University Avenue, Lowell, Massachusetts 01854, United States
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6
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Luo TL, Vanek ME, Gonzalez-Cabezas C, Marrs CF, Foxman B, Rickard AH. In vitro model systems for exploring oral biofilms: From single-species populations to complex multi-species communities. J Appl Microbiol 2022; 132:855-871. [PMID: 34216534 PMCID: PMC10505481 DOI: 10.1111/jam.15200] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/05/2021] [Accepted: 06/29/2021] [Indexed: 12/13/2022]
Abstract
Numerous in vitro biofilm model systems are available to study oral biofilms. Over the past several decades, increased understanding of oral biology and advances in technology have facilitated more accurate simulation of intraoral conditions and have allowed for the increased generalizability of in vitro oral biofilm studies. The integration of contemporary systems with confocal microscopy and 16S rRNA community profiling has enhanced the capabilities of in vitro biofilm model systems to quantify biofilm architecture and analyse microbial community composition. In this review, we describe several model systems relevant to modern in vitro oral biofilm studies: the constant depth film fermenter, Sorbarod perfusion system, drip-flow reactor, modified Robbins device, flowcells and microfluidic systems. We highlight how combining these systems with confocal microscopy and community composition analysis tools aids exploration of oral biofilm development under different conditions and in response to antimicrobial/anti-biofilm agents. The review closes with a discussion of future directions for the field of in vitro oral biofilm imaging and analysis.
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Affiliation(s)
- Ting L. Luo
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Michael E. Vanek
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Carlos Gonzalez-Cabezas
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Carl F. Marrs
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Betsy Foxman
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Alexander H. Rickard
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
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7
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Fernández CE, Luo TL, González-Cabezas C, Rickard AH. Unsweetened and Sucrose-Sweetened Black and Green Tea Modifies the Architecture of In vitro Oral Biofilms. Arch Oral Biol 2022; 135:105368. [DOI: 10.1016/j.archoralbio.2022.105368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 11/02/2022]
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8
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Makvandi P, Josic U, Delfi M, Pinelli F, Jahed V, Kaya E, Ashrafizadeh M, Zarepour A, Rossi F, Zarrabi A, Agarwal T, Zare EN, Ghomi M, Kumar Maiti T, Breschi L, Tay FR. Drug Delivery (Nano)Platforms for Oral and Dental Applications: Tissue Regeneration, Infection Control, and Cancer Management. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:2004014. [PMID: 33898183 PMCID: PMC8061367 DOI: 10.1002/advs.202004014] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/12/2020] [Indexed: 05/09/2023]
Abstract
The oral cavity and oropharynx are complex environments that are susceptible to physical, chemical, and microbiological insults. They are also common sites for pathological and cancerous changes. The effectiveness of conventional locally-administered medications against diseases affecting these oral milieus may be compromised by constant salivary flow. For systemically-administered medications, drug resistance and adverse side-effects are issues that need to be resolved. New strategies for drug delivery have been investigated over the last decade to overcome these obstacles. Synthesis of nanoparticle-containing agents that promote healing represents a quantum leap in ensuring safe, efficient drug delivery to the affected tissues. Micro/nanoencapsulants with unique structures and properties function as more favorable drug-release platforms than conventional treatment approaches. The present review provides an overview of newly-developed nanocarriers and discusses their potential applications and limitations in various fields of dentistry and oral medicine.
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Affiliation(s)
- Pooyan Makvandi
- Chemistry Department, Faculty of ScienceShahid Chamran University of AhvazAhvaz6153753843Iran
| | - Uros Josic
- Department of Biomedical and Neuromotor SciencesUniversity of BolognaVia San Vitale 59Bologna40125Italy
| | - Masoud Delfi
- Department of Chemical SciencesUniversity of Naples “Federico II”Complesso Universitario Monte S. Angelo, Via CintiaNaples80126Italy
| | - Filippo Pinelli
- Department of Chemistry, Materials and Chemical EngineeringPolitecnico di Milano Technical UniversityMilano20133Italy
| | - Vahid Jahed
- Biomedical Engineering Division, Faculty of Chemical EngineeringTarbiat Modares UniversityTehranIran
| | - Emine Kaya
- Faculty of DentistryIstanbul Okan UniversityTuzla CampusTuzlaIstanbul34959Turkey
| | - Milad Ashrafizadeh
- Faculty of Engineering and Natural SciencesSabanci UniversityOrta Mahalle, Üniversite Caddesi No. 27, OrhanlıTuzlaIstanbul34956Turkey
- Sabanci University Nanotechnology Research and Application Center (SUNUM)TuzlaIstanbul34956Turkey
| | - Atefeh Zarepour
- Sabanci University Nanotechnology Research and Application Center (SUNUM)TuzlaIstanbul34956Turkey
| | - Filippo Rossi
- Department of Chemistry, Materials and Chemical EngineeringPolitecnico di Milano Technical UniversityMilano20133Italy
| | - Ali Zarrabi
- Sabanci University Nanotechnology Research and Application Center (SUNUM)TuzlaIstanbul34956Turkey
| | - Tarun Agarwal
- Department of BiotechnologyIndian Institute of Technology KharagpurKharagpurWest Bengal721302India
| | | | - Matineh Ghomi
- Chemistry Department, Faculty of ScienceShahid Chamran University of AhvazAhvaz6153753843Iran
| | - Tapas Kumar Maiti
- Department of BiotechnologyIndian Institute of Technology KharagpurKharagpurWest Bengal721302India
| | - Lorenzo Breschi
- Department of Biomedical and Neuromotor SciencesUniversity of BolognaVia San Vitale 59Bologna40125Italy
| | - Franklin R Tay
- The Dental College of GeorgiaAugusta University1430 John Wesley Gilbert DriveAugustaGA30192USA
- The Graduate SchoolAugusta UniversityAugustaGA30912USA
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Legner M, Jonkman J, Swift D. Evaluating the Effects of Disinfectants on Bacterial Biofilms Using a Microfluidics Flow Cell and Time-Lapse Fluorescence Microscopy. Microorganisms 2020; 8:microorganisms8111837. [PMID: 33266442 PMCID: PMC7700140 DOI: 10.3390/microorganisms8111837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 12/03/2022] Open
Abstract
A commercially available microfluidics flow cell was utilized together with widefield fluorescence microscopy to evaluate the effects of disinfectants on bacterial strains. The flow cell’s inner surface supports the formation of biofilms of numerous bacterial species. The modular setup of the flow cell accessories allows connection to syringes, pumps and collection vials, facilitating aseptic experiments in a controlled fluidics environment which can be documented with precisely timed microscopy imaging. The flow cell is inoculated with a suspension of bacteria in a nutrient medium and incubated for several days allowing bacterial cells to form a biofilm. Shortly before performing an assay, the biofilm is labelled with a dual-fluorescent DNA probe which distinguishes unharmed and damaged bacteria. Then a disinfectant sample (or control) is gently injected and time-lapse imaging is used for quantifying the course of bacterial biomass response. We use a simplified widefield microscopy method that allows intensive recording and quantification of time series of two-dimensional frames for tracking the course of disinfectant action on a variety of microbial strains. This procedure has potential for the rapid evaluation of novel products.
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Affiliation(s)
- Milos Legner
- Micrylium Laboratories, Toronto, ON M3H 5T5, Canada;
- Correspondence:
| | - James Jonkman
- Advanced Optical Microscopy Facility, University Health Network, Toronto, ON M5G 1L7, Canada;
| | - Dean Swift
- Micrylium Laboratories, Toronto, ON M3H 5T5, Canada;
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10
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Signori C, Maske TT, Digmayer Romero VH, Cenci MS. Influence of biofilm removal from the tooth-restoration interface on the progression of secondary caries lesions: a preliminary in vitro model study. BIOFOULING 2020; 36:1272-1283. [PMID: 33401970 DOI: 10.1080/08927014.2020.1870219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 12/21/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
This study investigated the effects of biofilm removal from the tooth-restoration surface on secondary caries lesion progression. Biofilms were grown for up to 28 days on resin-restored enamel-dentin disks with an interfacial gap with DMM or DMM + 1% sucrose under five different protocols of Visible Biofilm Removal (V-BR; n = 7): (1) without V-BR, (2) with partial V-BR, (3) with total V-BR, (4) with total V-BR and saliva reinoculation, and (5) without V-BR under 9 h of cariogenic challenge. V-BR was performed at 7, 14 and 21 days. ΔS and CFU counts served as outcome variables. Linear regression models showed that ΔS values were higher for outer lesions than wall lesions, and outer lesion progression generally increased over time (p < 0.01). All protocols tested, except total V-BR, increased the lactobacilli count (p < 0.005). V-BR did not influence the progression of caries lesions on the cavity wall in this biofilm model.
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Affiliation(s)
- Cácia Signori
- Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil
- School of Dentistry, UniAvan University Center, Balneário Camboriú, Brazil
| | - Tamires Timm Maske
- Graduate Program in Dentistry, Federal University of Pelotas, Pelotas, Brazil
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11
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Mouhat M, Moorehead R, Murdoch C. In vitro Candida albicans biofilm formation on different titanium surface topographies. Biomater Investig Dent 2020; 7:146-157. [PMID: 33134957 PMCID: PMC7580804 DOI: 10.1080/26415275.2020.1829489] [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] [Indexed: 11/23/2022] Open
Abstract
Objectives To investigate if differences in titanium implant surface topography influence Candida albicans biofilm formation. Materials and Methods Titanium discs were prepared and characterized using a profilometer: Group A (Ra 0.15 µm, smooth), Group B (Ra 0.64 µm, minimally rough) and Group C (Ra 1.3 µm, moderately rough). Contact angle and surface free energy (SFE) were determined for each group. Non-preconditioned titanium discs were incubated with C. albicans for 24 h. In additional experiments, the titanium discs were initially coated with human saliva, bovine serum albumin or phosphate-buffered saline for 2 h before incubation with C. albicans for 24 h. The amount of fungal biofilm formation was quantified using a colorimetric assay. Results C. albicans biofilm formation was significantly lower (p < 0.05) on the minimally rough titanium surface compared to smooth and moderately rough surfaces. The titanium surface displaying the lowest SFE (Group B) was associated with significantly lower (p < 0.05) C. albicans biofilm formation than the other two groups. Salivary coating resulted in greater adherence of C. albicans with increased surface roughness. Conclusions The minimally rough titanium discs displayed lowest SFE compared to smooth and moderately rough surfaces and showed the least C. albicans biofilm formation. This study demonstrated that C. albicans biofilm formation increased in a SFE-dependent manner. These findings suggest that SFE might be a more explanatory factor for C. albicans biofilm formation on titanium surfaces than roughness. The presence of a pellicle coating may negate the impact of SFE on C. albicans biofilm formation on titanium surfaces.
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Affiliation(s)
- Mathieu Mouhat
- Department for Clinical Dentistry, Faculty of Health Sciences, The Arctic University of Norway (UiT), Tromsø, Norway.,School of Clinical Dentistry, The University of Sheffield, Sheffield, UK
| | - Robert Moorehead
- The Henry Royce Institute, The University of Sheffield, Sheffield, UK
| | - Craig Murdoch
- School of Clinical Dentistry, The University of Sheffield, Sheffield, UK
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12
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Turner ME, Huynh K, Carney OV, Gross D, Carroll RK, Ahn SJ, Rice KC. Genomic instability of TnSMU2 contributes to Streptococcus mutans biofilm development and competence in a cidB mutant. Microbiologyopen 2019; 8:e934. [PMID: 31599128 PMCID: PMC6925190 DOI: 10.1002/mbo3.934] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/20/2019] [Accepted: 08/21/2019] [Indexed: 02/06/2023] Open
Abstract
Streptococcus mutans is a key pathogenic bacterium in the oral cavity and a primary contributor to dental caries. The S. mutans Cid/Lrg system likely contributes to tolerating stresses encountered in this environment as cid and/or lrg mutants exhibit altered oxidative stress sensitivity, genetic competence, and biofilm phenotypes. It was recently noted that the cidB mutant had two stable colony morphologies: a “rough” phenotype (similar to wild type) and a “smooth” phenotype. In our previously published work, the cidB rough mutant exhibited increased sensitivity to oxidative stress, and RNAseq identified widespread transcriptomic changes in central carbon metabolism and oxidative stress response genes. In this current report, we conducted Illumina‐based genome resequencing of wild type, cidB rough, and cidB smooth mutants and compared their resistance to oxidative and acid stress, biofilm formation, and competence phenotypes. Both cidB mutants exhibited comparable aerobic growth inhibition on agar plates, during planktonic growth, and in the presence of 1 mM hydrogen peroxide. The cidB smooth mutant displayed a significant competence defect in BHI, which was rescuable by synthetic CSP. Both cidB mutants also displayed reduced XIP‐mediated competence, although this reduction was more pronounced in the cidB smooth mutant. Anaerobic biofilms of the cidB smooth mutant displayed increased propidium iodide staining, but corresponding biofilm CFU data suggest this phenotype is due to cell damage and not increased cell death. The cidB rough anaerobic biofilms showed altered structure relative to wild type (reduced biomass and average thickness) which correlated with decreased CFU counts. Sequencing data revealed that the cidB smooth mutant has a unique “loss of read coverage” of ~78 kb of DNA, corresponding to the genomic island TnSMU2 and genes flanking its 3′ end. It is therefore likely that the unique biofilm and competence phenotypes of the cidB smooth mutant are related to its genomic changes in this region.
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Affiliation(s)
- Matthew E Turner
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Khanh Huynh
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - O'neshia V Carney
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Dennis Gross
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH, USA
| | - Sang-Joon Ahn
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
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13
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Spontaneously Arising Streptococcus mutans Variants with Reduced Susceptibility to Chlorhexidine Display Genetic Defects and Diminished Fitness. Antimicrob Agents Chemother 2019; 63:AAC.00161-19. [PMID: 31036688 DOI: 10.1128/aac.00161-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 04/20/2019] [Indexed: 01/10/2023] Open
Abstract
Chlorhexidine (CHX) has been used to control dental caries caused by acid-tolerant bacteria such as Streptococcus mutans since the 1970s. Repeat CHX exposure for other bacterial species results in the development of variants with reduced susceptibility that also become more resistant to other antimicrobials. It has not been tested if such variants arise when streptococci are exposed to CHX. Here, we passaged S. mutans in increasing concentrations of CHX and isolated spontaneously arising reduced susceptibility variants (RSVs) from separate lineages that have MICs that are up to 3-fold greater than the parental strain. The RSVs have increased growth rates at neutral pH and under acidic conditions in the presence of CHX but accumulate less biomass in biofilms. RSVs display higher MICs for daptomycin and clindamycin but increased sensitivity to dental-relevant antimicrobials triclosan and sodium fluoride. Plate-based assays for competition with health-associated oral streptococci revealed decreased bacteriocin production by the RSVs, increased sensitivity to hydrogen peroxide, and diminished competitive fitness in a human-derived ex vivo biofilm consortium. Whole-genome sequencing identified common single nucleotide polymorphisms (SNPs) within a diacylglycerol kinase homolog and a glycolipid synthesis enzyme, which could alter the accumulation of lipoteichoic acids and other envelope constituents, as well as a variety of mutations in other genes. Collectively, these findings confirm that S. mutans and likely other streptococci can develop tolerance to CHX but that increased tolerance comes at a fitness cost, such that CHX-induced variants that spontaneously arise in the human oral cavity may not persist.
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14
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Amino Sugars Modify Antagonistic Interactions between Commensal Oral Streptococci and Streptococcus mutans. Appl Environ Microbiol 2019; 85:AEM.00370-19. [PMID: 30877119 DOI: 10.1128/aem.00370-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 03/12/2019] [Indexed: 02/05/2023] Open
Abstract
N-Acetylglucosamine (GlcNAc) and glucosamine (GlcN) enhance the competitiveness of the laboratory strain DL1 of Streptococcus gordonii against the caries pathogen Streptococcus mutans Here, we examine how amino sugars affect the interaction of five low-passage-number clinical isolates of abundant commensal streptococci with S. mutans by utilizing a dual-species biofilm model. Compared to that for glucose, growth on GlcN or GlcNAc significantly reduced the viability of S. mutans in cocultures with most commensals, shifting the proportions of species. Consistent with these results, production of H2O2 was increased in most commensals when growing on amino sugars, and inhibition of S. mutans by Streptococcus cristatus, Streptococcus oralis, or S. gordonii was enhanced by amino sugars on agar plates. All commensals except S. oralis had higher arginine deiminase activities when grown on GlcN and, in some cases, GlcNAc. In ex vivo biofilms formed using pooled cell-containing saliva (CCS), the proportions of S. mutans were drastically diminished when GlcNAc was the primary carbohydrate. Increased production of H2O2 could account in large part for the inhibitory effects of CCS biofilms. Surprisingly, amino sugars appeared to improve mutacin production by S. mutans on agar plates, suggesting that the commensals have mechanisms to actively subvert antagonism by S. mutans in cocultures. Collectively, these findings demonstrate that amino sugars can enhance the beneficial properties of low-passage-number commensal oral streptococci and highlight their potential for moderating the cariogenicity of oral biofilms.IMPORTANCE Dental caries is driven by dysbiosis of oral biofilms in which dominance by acid-producing and acid-tolerant bacteria results in loss of tooth mineral. Our previous work demonstrated the beneficial effects of amino sugars GlcNAc and GlcN in promoting the antagonistic properties of a health-associated oral bacterium, Streptococcus gordonii, in competition with the major caries pathogen Streptococcus mutans Here, we investigated 5 low-passage-number clinical isolates of the most common streptococcal species to establish how amino sugars may influence the ecology and virulence of oral biofilms. Using multiple in vitro models, including a human saliva-derived microcosm biofilm, experiments showed significant enhancement by at least one amino sugar in the ability of most of these bacteria to suppress the caries pathogen. Therefore, our findings demonstrated the mechanism of action by which amino sugars may affect human oral biofilms to promote health.
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15
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Legner M, McMillen DR, Cvitkovitch DG. Role of Dilution Rate and Nutrient Availability in the Formation of Microbial Biofilms. Front Microbiol 2019; 10:916. [PMID: 31114560 PMCID: PMC6503106 DOI: 10.3389/fmicb.2019.00916] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 04/10/2019] [Indexed: 11/13/2022] Open
Abstract
We revisited the mathematical model of the chemostat and examined consequences of considerably decreasing the concentration of limiting nutrient in the inflow for the growth of both the planktonic and biofilm cells in the chemostat tank (fermenter). The model predicts a substantially lower steady-state biomass of planktonic cells in response to decreasing inflowing nutrient concentration. Contrarily, the steady-state concentration of nutrient inside the fermenter is expected to remain the same, as long as the inflowing concentration does not fall below its value. This allows the biofilm cells to grow at a rate regulated only by the exchange rate of the medium (dilution rate). We maintained a strain of Enterococcus faecalis in a chemostat of our own design with limiting nutrient in the inflow set near saturation constant at three dilution rates (0.09, 0.28, and 0.81 h-1). The highest dilution rate was near the critical rate calculated by the model. The one-day total biofilm buildup was 21× larger and its estimated growth rate 2.4× higher at highest dilution rate than at the lowest one. This increased biofilm formation with increased dilution rates is in agreement with previously published data on pure and mixed continuous flow cultures.
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Affiliation(s)
- Milos Legner
- Discipline of Microbiology, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - David R McMillen
- Department of Chemical and Physical Sciences and Impact Centre, University of Toronto Mississauga, Mississauga, ON, Canada
| | - Dennis G Cvitkovitch
- Discipline of Microbiology, Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
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16
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Fernández CE, Aspiras M, Dodds MW, González-Cabezas C, Rickard AH. Combinatorial effect of magnolia bark extract and ethyl lauroyl arginate against multi-species oral biofilms: Food additives with the potential to prevent biofilm-related oral diseases. J Funct Foods 2018. [DOI: 10.1016/j.jff.2018.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2022] Open
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