51
|
Cheng X, Redanz S, Treerat P, Qin H, Choi D, Zhou X, Xu X, Merritt J, Kreth J. Magnesium-Dependent Promotion of H 2O 2 Production Increases Ecological Competitiveness of Oral Commensal Streptococci. J Dent Res 2020; 99:847-854. [PMID: 32197054 PMCID: PMC7313347 DOI: 10.1177/0022034520912181] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The pyruvate oxidase (SpxB)-dependent production of H2O2 is widely distributed among oral commensal streptococci. Several studies confirmed the ability of H2O2 to antagonize susceptible oral bacterial species, including caries-associated Streptococcus mutans as well as several periodontal pathobionts. Here we report a potential mechanism to bolster oral commensal streptococcal H2O2 production by magnesium (Mg2+) supplementation. Magnesium is a cofactor for SpxB catalytic activity, and supplementation increases the production of H2O2 in vitro. We demonstrate that Mg2+ affects spxB transcription and SpxB abundance in Streptococcus sanguinis and Streptococcus gordonii. The competitiveness of low-passage commensal streptococcal clinical isolates is positively influenced in antagonism assays against S. mutans. In growth conditions normally selective for S. mutans, Mg2+ supplementation is able to increase the abundance of S. sanguinis in dual-species biofilms. Using an in vivo biophotonic imaging platform, we further demonstrate that dietary Mg2+ supplementation significantly improves S. gordonii oral colonization in mice. In summary, our results support a role for Mg2+ supplementation as a potential prebiotic to promote establishment of oral health-associated commensal streptococci.
Collapse
Affiliation(s)
- X. Cheng
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China,Department of Geriatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - S. Redanz
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
| | - P. Treerat
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
| | - H. Qin
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
| | - D. Choi
- Department of Community Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA,School of Public Health, Oregon Health & Science University, Portland, OR, USA
| | - X. Zhou
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China,Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - X. Xu
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China,Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - J. Merritt
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA,Department of Restorative Dentistry, Oregon Health and Science University, Portland, OR, USA
| | - J. Kreth
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA,Department of Restorative Dentistry, Oregon Health and Science University, Portland, OR, USA,J. Kreth, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., MRB433, Portland, OR 97239, USA.
| |
Collapse
|
52
|
Smith AB, Soto Ocana J, Zackular JP. From Nursery to Nursing Home: Emerging Concepts in Clostridioides difficile Pathogenesis. Infect Immun 2020; 88:IAI.00934-19. [PMID: 32122939 PMCID: PMC7309631 DOI: 10.1128/iai.00934-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Clostridioides difficile is a Gram-positive, spore-forming, anaerobic bacterium that infects the human gastrointestinal tract, causing a wide range of disorders that vary in severity from mild diarrhea to toxic megacolon and/or death. Over the past decade, incidence, severity, and costs associated with C. difficile infection (CDI) have increased dramatically in both the pediatric and adult populations. The factors driving this rapidly evolving epidemiology remain largely unknown but are likely due in part to previously unappreciated host, microbiota, and environmental factors. In this review, we will cover the risks and challenges of CDI in adult and pediatric populations and examine asymptomatic colonization in infants. We will also discuss the emerging role of diet, pharmaceutical drugs, and pathogen-microbiota interactions in C. difficile pathogenesis, as well as the impact of host-microbiota interactions in the manifestation of C. difficile-associated disease. Finally, we highlight new areas of research and novel strategies that may shed light on this complex infection and provide insights into the future of microbiota-based therapeutics for CDI.
Collapse
Affiliation(s)
- Alexander B Smith
- Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joshua Soto Ocana
- Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Joseph P Zackular
- Division of Protective Immunity, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|
53
|
Chathoth K, Martin B, Cornelis P, Yvenou S, Bonnaure-Mallet M, Baysse C. The events that may contribute to subgingival dysbiosis: a focus on the interplay between iron, sulfide and oxygen. FEMS Microbiol Lett 2020; 367:5860280. [DOI: 10.1093/femsle/fnaa100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 06/19/2020] [Indexed: 12/21/2022] Open
Abstract
ABSTRACT
This minireview considers the disruption of the host–microbiota harmless symbiosis in the subgingival niche. The establishment of a chronic infection by subversion of a commensal microbiota results from a complex and multiparametric sequence of events. This review narrows down to the interplay between oxygen, iron and sulfide that can result in a vicious cycle that would favor peroxygenic and glutathione producing streptococci as well as sulfidogenic anaerobic pathogens in the subgingival niche. We propose hypothesis and discuss strategies for the therapeutic modulation of the microbiota to prevent periodontitis and promote oral health.
Collapse
Affiliation(s)
- Kanchana Chathoth
- NuMeCan INSERM U1241, CIMIAD, Université de Rennes 1, F-35043 Rennes, France
| | - Bénédicte Martin
- NuMeCan INSERM U1241, CIMIAD, Université de Rennes 1, F-35043 Rennes, France
| | - Pierre Cornelis
- Department of Bioengineering Sciences, Laboratory of Microbiology, Vrije Universiteit Brussel, B-1050 Brussels, Belgium
- Laboratoire de Microbiologie Signaux et Microenvironnement, LMSM EA4312, Université de Rouen Normandie, Normandie Université, F-27000 Évreux, France
| | - Stéven Yvenou
- NuMeCan INSERM U1241, CIMIAD, Université de Rennes 1, F-35043 Rennes, France
| | - Martine Bonnaure-Mallet
- NuMeCan INSERM U1241, CIMIAD, Université de Rennes 1, F-35043 Rennes, France
- CHU Pontchaillou Rennes, 35000 Rennes, France
| | - Christine Baysse
- NuMeCan INSERM U1241, CIMIAD, Université de Rennes 1, F-35043 Rennes, France
| |
Collapse
|
54
|
Pacheco AR, Segrè D. A multidimensional perspective on microbial interactions. FEMS Microbiol Lett 2020; 366:5513995. [PMID: 31187139 PMCID: PMC6610204 DOI: 10.1093/femsle/fnz125] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/10/2019] [Indexed: 12/16/2022] Open
Abstract
Beyond being simply positive or negative, beneficial or inhibitory, microbial interactions can involve a diverse set of mechanisms, dependencies and dynamical properties. These more nuanced features have been described in great detail for some specific types of interactions, (e.g. pairwise metabolic cross-feeding, quorum sensing or antibiotic killing), often with the use of quantitative measurements and insight derived from modeling. With a growing understanding of the composition and dynamics of complex microbial communities for human health and other applications, we face the challenge of integrating information about these different interactions into comprehensive quantitative frameworks. Here, we review the literature on a wide set of microbial interactions, and explore the potential value of a formal categorization based on multidimensional vectors of attributes. We propose that such an encoding can facilitate systematic, direct comparisons of interaction mechanisms and dependencies, and we discuss the relevance of an atlas of interactions for future modeling and rational design efforts.
Collapse
Affiliation(s)
- Alan R Pacheco
- Graduate Program in Bioinformatics and Biological Design Center, Boston University, 24 Cummington Mall, Boston, MA, 02215, USA
| | - Daniel Segrè
- Graduate Program in Bioinformatics and Biological Design Center, Boston University, 24 Cummington Mall, Boston, MA, 02215, USA.,Department of Biomedical Engineering, Department of Biology and Department of Physics, Boston University, 24 Cummington Mall, Boston, MA, 02215, USA
| |
Collapse
|
55
|
Ibberson CB, Whiteley M. The social life of microbes in chronic infection. Curr Opin Microbiol 2020; 53:44-50. [PMID: 32145635 DOI: 10.1016/j.mib.2020.02.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/24/2020] [Accepted: 02/02/2020] [Indexed: 01/21/2023]
Abstract
Chronic infections place a significant burden on healthcare systems, requiring over $25 billion in treatment annually in the United States alone [1,2]. Notably, the majority of chronic infections, which include cystic fibrosis (CF), chronic wounds, otitis media, periodontitis, urinary tract infections, and osteomyelitis, are considered polymicrobial and are often recalcitrant to antibiotic treatment [1-9]. Although we know that diverse communities of microbes comprise these infections, how microbes interact and the impacts of these interactions on human disease are less understood. Here, we discuss recent advances in our understanding of how bacteria communicate in chronic infection, with a focus on Staphylococcus aureus and Pseudomonas aeruginosa, and we highlight outstanding questions and controversies in the field.
Collapse
Affiliation(s)
- Carolyn B Ibberson
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States; Emory-Children's Cystic Fibrosis Center, Atlanta, GA 30332, United States; Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332, United States.
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States; Emory-Children's Cystic Fibrosis Center, Atlanta, GA 30332, United States; Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332, United States
| |
Collapse
|
56
|
Vuong HQ, McFrederick QS. Comparative Genomics of Wild Bee and Flower Isolated Lactobacillus Reveals Potential Adaptation to the Bee Host. Genome Biol Evol 2020; 11:2151-2161. [PMID: 31243442 PMCID: PMC6685495 DOI: 10.1093/gbe/evz136] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/24/2019] [Indexed: 01/18/2023] Open
Abstract
Symbiosis with bacteria is common across insects, resulting in adaptive host phenotypes. The recently described bacterial symbionts Lactobacillus micheneri, Lactobacillus timberlakei, and Lactobacillus quenuiae are found in wild bee pollen provisions, bee guts, and flowers but have small genomes in comparison to other lactobacilli. We sequenced, assembled, and analyzed 27 new L. micheneri clade genomes to identify their possible ecological functions in flower and bee hosts. We determined possible key functions for the L. micheneri clade by identifying genes under positive selection, balancing selection, genes gained or lost, and population structure. A host adherence factor shows signatures of positive selection, whereas other orthologous copies are variable within the L. micheneri clade. The host adherence factors serve as strong evidence that these lactobacilli are adapted to animal hosts as their targets are found in the digestive tract of insects. Next, the L. micheneri clade is adapted toward a nutrient-rich environment, corroborating observations of where L. micheneri is most abundant. Additionally, genes involved in osmotolerance, pH tolerance, temperature resistance, detoxification, and oxidative stress response show signatures of selection that allow these bacteria to thrive in pollen and nectar masses in bee nests and in the bee gut. Altogether, these findings not only suggest that the L. micheneri clade is primarily adapted to the wild bee gut but also exhibit genomic features that would be beneficial to survival in flowers.
Collapse
Affiliation(s)
- Hoang Q Vuong
- Department of Entomology, University California Riverside.,Department of Plant Pathology and Microbiology, University California Riverside
| | | |
Collapse
|
57
|
Short-range interactions govern the dynamics and functions of microbial communities. Nat Ecol Evol 2020; 4:366-375. [DOI: 10.1038/s41559-019-1080-2] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 12/02/2019] [Indexed: 11/08/2022]
|
58
|
Abstract
The etiopathogenesis of severe periodontitis includes herpesvirus-bacteria coinfection. This article evaluates the pathogenicity of herpesviruses (cytomegalovirus and Epstein-Barr virus) and periodontopathic bacteria (Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) and coinfection of these infectious agents in the initiation and progression of periodontitis. Cytomegalovirus and A. actinomycetemcomitans/P. gingivalis exercise synergistic pathogenicity in the development of localized ("aggressive") juvenile periodontitis. Cytomegalovirus and Epstein-Barr virus are associated with P. gingivalis in adult types of periodontitis. Periodontal herpesviruses that enter the general circulation may also contribute to disease development in various organ systems. A 2-way interaction is likely to occur between periodontal herpesviruses and periodontopathic bacteria, with herpesviruses promoting bacterial upgrowth, and bacterial factors reactivating latent herpesviruses. Bacterial-induced gingivitis may facilitate herpesvirus colonization of the periodontium, and herpesvirus infections may impede the antibacterial host defense and alter periodontal cells to predispose for bacterial adherence and invasion. Herpesvirus-bacteria synergistic interactions, are likely to comprise an important pathogenic determinant of aggressive periodontitis. However, mechanistic investigations into the molecular and cellular interaction between periodontal herpesviruses and bacteria are still scarce. Herpesvirus-bacteria coinfection studies may yield significant new discoveries of pathogenic determinants, and drug and vaccine targets to minimize or prevent periodontitis and periodontitis-related systemic diseases.
Collapse
Affiliation(s)
- Casey Chen
- Division of Periodontology, Diagnostic Sciences & Dental Hygiene, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA
| | - Pinghui Feng
- Section of Infection and Immunity, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA
| | - Jørgen Slots
- Division of Periodontology, Diagnostic Sciences & Dental Hygiene, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California, USA
| |
Collapse
|
59
|
Ansarizadeh M, Haddadi SA, Amini M, Hasany M, Ramazani SaadatAbadi A. Sustained release of CIP from TiO
2
‐PVDF/starch nanocomposite mats with potential application in wound dressing. J Appl Polym Sci 2020. [DOI: 10.1002/app.48916] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mohamadhasan Ansarizadeh
- Chemical and Petroleum Engineering DepartmentSharif University of Technology P.O. Box: 11365‐9465 Tehran Iran
- Oulu Center for Cell‐Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular MedicineUniversity of Oulu Oulu Finland
| | - Seyyed Arash Haddadi
- Chemical and Petroleum Engineering DepartmentSharif University of Technology P.O. Box: 11365‐9465 Tehran Iran
- School of EngineeringUniversity of British Columbia Kelowna British Columbia V1V 1V7 Canada
| | - Majed Amini
- Chemical and Petroleum Engineering DepartmentSharif University of Technology P.O. Box: 11365‐9465 Tehran Iran
| | - Masoud Hasany
- Chemical and Petroleum Engineering DepartmentSharif University of Technology P.O. Box: 11365‐9465 Tehran Iran
| | - Ahmad Ramazani SaadatAbadi
- Chemical and Petroleum Engineering DepartmentSharif University of Technology P.O. Box: 11365‐9465 Tehran Iran
| |
Collapse
|
60
|
Røder HL, Olsen NMC, Whiteley M, Burmølle M. Unravelling interspecies interactions across heterogeneities in complex biofilm communities. Environ Microbiol 2019; 22:5-16. [DOI: 10.1111/1462-2920.14834] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/15/2019] [Accepted: 10/17/2019] [Indexed: 01/29/2023]
Affiliation(s)
- Henriette L. Røder
- Section of Microbiology, Department of BiologyUniversity of Copenhagen Copenhagen Denmark
| | - Nanna M. C. Olsen
- Section of Microbiology, Department of BiologyUniversity of Copenhagen Copenhagen Denmark
| | - Marvin Whiteley
- School of Biological SciencesGeorgia Institute of Technology, Atlanta Georgia USA
- Emory‐Children's Cystic Fibrosis Center, Atlanta Georgia USA
- Center for Microbial Dynamics and InfectionGeorgia Institute of Technology, Atlanta Georgia USA
| | - Mette Burmølle
- Section of Microbiology, Department of BiologyUniversity of Copenhagen Copenhagen Denmark
| |
Collapse
|
61
|
Wang Y, Feng T, Li H, Yu Y, Han Y, Zhang J, Li X, Li Y, Zhang XH. A novel heterologous expression strategy for the quorum-quenching enzyme MomL in Lysobacter enzymogenes to the inhibit pathogenicity of Pectobacterium. Appl Microbiol Biotechnol 2019; 103:8889-8898. [PMID: 31656979 DOI: 10.1007/s00253-019-10166-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/20/2019] [Accepted: 09/28/2019] [Indexed: 01/28/2023]
Abstract
Quorum-quenching (QQ) enzymes can block the quorum-sensing (QS) system and prevent the expression of QS-controlled pathogenic factors in bacteria. However, the low expression levels of QQ proteins in the original host bacteria have affected their widespread application. In this study, we heterologously expressed momL, encoding a QQ enzyme with high activity, in Lysobacter enzymogenes. A "yellow-to-white" selection marker and the high-constitutive-expression promoter PgroEL were used in this novel heterologous expression system. In addition, we optimized the spacer between the SD sequence and the initiator to improve the efficiency of the expression system by 1.54-fold. The engineered strain LeMomL degraded the AHL molecule and the virulence factors of Pectobacterium carotovorum subsp. carotovora (Pcc). Additionally, LeMomL significantly decreased the disease caused by Pcc in Chinese cabbages and carrot root tissues. In conclusion, this novel and facile L. enzymogenes expression strategy has good prospects and is an ideal approach for foreign protein expression.
Collapse
Affiliation(s)
- Yan Wang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China. .,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China. .,Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
| | - Tao Feng
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Hui Li
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Yameng Yu
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Yong Han
- Edison Biotechnology Institute, Ohio University, Athens, OH, 45701, USA
| | - Jingjing Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Xiaoyu Li
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Yaoyao Li
- Key Laboratory of Chemical Biology, School of Pharmaceutical Sciences, Shandong University, Jinan, 250100, China
| | - Xiao-Hua Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China. .,Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China. .,Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao, 266003, China.
| |
Collapse
|
62
|
Aggregatibacter actinomycetemcomitans colonization and persistence in a primate model. Proc Natl Acad Sci U S A 2019; 116:22307-22313. [PMID: 31611409 DOI: 10.1073/pnas.1905238116] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans is associated with aggressive periodontitis resulting in premature tooth loss in adolescents. Tooth adherence and biofilm persistence are prerequisites for survival in the oral domain. Here, using a rhesus monkey model, 16S rRNA sequencing, and weighted network analysis, we assessed colonization of A. actinomycetemcomitans variants and ascertained microbial interactions in biofilm communities. Variants in A. actinomycetemcomitans leukotoxin (ltx) were created, labeled, inoculated, and compared with their progenitor strain for in vivo colonization. Samples of tooth-related plaque were assessed for colonization at baseline and after debridement and inoculation of labeled strains. Null, minimal, and hyper-Ltx-producing strains were created and assessed for hydroxyapatite binding and biofilm formation in vitro. Ltx-hyperproducing strains colonized with greater prevalence and at higher levels than wild type or ltx mutants (P = 0.05). Indigenous and inoculated A. actinomycetemcomitans strains that attached were associated with lactate-producing species (i.e., Leptotrichia, Abiotrophia, and Streptoccocci). A. actinomycetemcomitans was found at 0.13% of the total flora at baseline and at 0.05% 4 wk after inoculation. In vivo data were supported by in vitro results. We conclude that hyper-Ltx production affords these strains with an attachment advantage providing a foothold for competition with members of the indigenous microbiota. Increased attachment can be linked to ltx gene expression and up-regulation of adherence-associated genes. Growth of attached A. actinomycetemcomitans in vivo was enhanced by lactate availability due to consorting species. These associations provide A. actinomycetemcomitans with the constituents required for its colonization and survival in the complex and competitive oral environment.
Collapse
|
63
|
Melnik AV, Vázquez-Baeza Y, Aksenov AA, Hyde E, McAvoy AC, Wang M, da Silva RR, Protsyuk I, Wu JV, Bouslimani A, Lim YW, Luzzatto-Knaan T, Comstock W, Quinn RA, Wong R, Humphrey G, Ackermann G, Spivey T, Brouha SS, Bandeira N, Lin GY, Rohwer F, Conrad DJ, Alexandrov T, Knight R, Dorrestein PC, Garg N. Molecular and Microbial Microenvironments in Chronically Diseased Lungs Associated with Cystic Fibrosis. mSystems 2019; 4:e00375-19. [PMID: 31551401 PMCID: PMC6759567 DOI: 10.1128/msystems.00375-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/02/2019] [Indexed: 02/07/2023] Open
Abstract
To visualize the personalized distributions of pathogens and chemical environments, including microbial metabolites, pharmaceuticals, and their metabolic products, within and between human lungs afflicted with cystic fibrosis (CF), we generated three-dimensional (3D) microbiome and metabolome maps of six explanted lungs from three cystic fibrosis patients. These 3D spatial maps revealed that the chemical environments differ between patients and within the lungs of each patient. Although the microbial ecosystems of the patients were defined by the dominant pathogen, their chemical diversity was not. Additionally, the chemical diversity between locales in the lungs of the same individual sometimes exceeded interindividual variation. Thus, the chemistry and microbiome of the explanted lungs appear to be not only personalized but also regiospecific. Previously undescribed analogs of microbial quinolones and antibiotic metabolites were also detected. Furthermore, mapping the chemical and microbial distributions allowed visualization of microbial community interactions, such as increased production of quorum sensing quinolones in locations where Pseudomonas was in contact with Staphylococcus and Granulicatella, consistent with in vitro observations of bacteria isolated from these patients. Visualization of microbe-metabolite associations within a host organ in early-stage CF disease in animal models will help elucidate the complex interplay between the presence of a given microbial structure, antibiotics, metabolism of antibiotics, microbial virulence factors, and host responses.IMPORTANCE Microbial infections are now recognized to be polymicrobial and personalized in nature. Comprehensive analysis and understanding of the factors underlying the polymicrobial and personalized nature of infections remain limited, especially in the context of the host. By visualizing microbiomes and metabolomes of diseased human lungs, we reveal how different the chemical environments are between hosts that are dominated by the same pathogen and how community interactions shape the chemical environment or vice versa. We highlight that three-dimensional organ mapping methods represent hypothesis-building tools that allow us to design mechanistic studies aimed at addressing microbial responses to other microbes, the host, and pharmaceutical drugs.
Collapse
Affiliation(s)
- Alexey V Melnik
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Yoshiki Vázquez-Baeza
- Jacobs School of Engineering, University of California, San Diego, La Jolla, California, USA
- UC San Diego Center for Microbiome Innovation, University of California, San Diego, La Jolla, California, USA
| | - Alexander A Aksenov
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Embriette Hyde
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Andrew C McAvoy
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Mingxun Wang
- Department of Computer Science & Engineering, University of California, San Diego, La Jolla, California, USA
| | - Ricardo R da Silva
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Ivan Protsyuk
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jason V Wu
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Amina Bouslimani
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Yan Wei Lim
- Biology Department, San Diego State University, San Diego, California, USA
| | - Tal Luzzatto-Knaan
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - William Comstock
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Robert A Quinn
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Richard Wong
- Department of Pathology, University of California, San Diego, La Jolla, California, USA
| | - Greg Humphrey
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Gail Ackermann
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
| | - Timothy Spivey
- Department of Radiology, University of California, San Diego, La Jolla, California, USA
| | - Sharon S Brouha
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Nuno Bandeira
- Department of Computer Science & Engineering, University of California, San Diego, La Jolla, California, USA
| | - Grace Y Lin
- Department of Pathology, University of California, San Diego, La Jolla, California, USA
| | - Forest Rohwer
- Biology Department, San Diego State University, San Diego, California, USA
| | - Douglas J Conrad
- Department of Medicine, University of California, San Diego, La Jolla, California, USA
| | - Theodore Alexandrov
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Rob Knight
- Department of Pediatrics, University of California, San Diego, La Jolla, California, USA
- Department of Computer Science & Engineering, University of California, San Diego, La Jolla, California, USA
- UC San Diego Center for Microbiome Innovation, University of California, San Diego, La Jolla, California, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Pieter C Dorrestein
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
| | - Neha Garg
- Collaborative Mass Spectrometry Innovation Center, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California, USA
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
- Emory-Children's Center for Cystic Fibrosis and Airways Disease Research, Atlanta, Georgia, USA
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, Georgia, USA
| |
Collapse
|
64
|
Lewin GR, Stacy A, Michie KL, Lamont RJ, Whiteley M. Large-scale identification of pathogen essential genes during coinfection with sympatric and allopatric microbes. Proc Natl Acad Sci U S A 2019; 116:19685-19694. [PMID: 31427504 PMCID: PMC6765283 DOI: 10.1073/pnas.1907619116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Recent evidence suggests that the genes an organism needs to survive in an environment drastically differ when alone or in a community. However, it is not known if there are universal functions that enable microbes to persist in a community and if there are functions specific to interactions between microbes native to the same (sympatric) or different (allopatric) environments. Here, we ask how the essential functions of the oral pathogen Aggregatibacter actinomycetemcomitans change during pairwise coinfection in a murine abscess with each of 15 microbes commonly found in the oral cavity and 10 microbes that are not. A. actinomycetemcomitans was more abundant when coinfected with allopatric than with sympatric microbes, and this increased fitness correlated with expanded metabolic capacity of the coinfecting microbes. Using transposon sequencing, we discovered that 33% of the A. actinomycetemcomitans genome is required for coinfection fitness. Fifty-nine "core" genes were required across all coinfections and included genes necessary for aerobic respiration. The core genes were also all required in monoinfection, indicating the essentiality of these genes cannot be alleviated by a coinfecting microbe. Furthermore, coinfection with some microbes, predominately sympatric species, induced the requirement for over 100 new community-dependent essential genes. In contrast, in other coinfections, predominately with nonoral species, A. actinomycetemcomitans required 50 fewer genes than in monoinfection, demonstrating that some allopatric microbes can drastically alleviate gene essentialities. These results expand our understanding of how diverse microbes alter growth and gene essentiality within polymicrobial infections.
Collapse
Affiliation(s)
- Gina R Lewin
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332
- Emory-Children's Cystic Fibrosis Center, Atlanta, GA 30324
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332
| | - Apollo Stacy
- Metaorganism Immunity Section, Laboratory of Immune System Biology, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892
- Postdoctoral Research Associate Training Program, National Institute of General Medical Sciences, Bethesda, MD 20892
| | - Kelly L Michie
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332
- Emory-Children's Cystic Fibrosis Center, Atlanta, GA 30324
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY 40202
| | - Marvin Whiteley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332;
- Emory-Children's Cystic Fibrosis Center, Atlanta, GA 30324
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332
| |
Collapse
|
65
|
Keshvardoust P, Huron VAA, Clemson M, Constancias F, Barraud N, Rice SA. Biofilm formation inhibition and dispersal of multi-species communities containing ammonia-oxidising bacteria. NPJ Biofilms Microbiomes 2019; 5:22. [PMID: 31482007 PMCID: PMC6711990 DOI: 10.1038/s41522-019-0095-4] [Citation(s) in RCA: 12] [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: 12/11/2018] [Accepted: 08/02/2019] [Indexed: 02/01/2023] Open
Abstract
Despite considerable research, the biofilm-forming capabilities of Nitrosomonas europaea are poorly understood for both mono and mixed-species communities. This study combined biofilm assays and molecular techniques to demonstrate that N. europaea makes very little biofilm on its own, and relies on the activity of associated heterotrophic bacteria to establish a biofilm. However, N. europaea has a vital role in the proliferation of mixed-species communities under carbon-limited conditions, such as in drinking water distribution systems, through the provision of organic carbon via ammonia oxidation. Results show that the addition of nitrification inhibitors to mixed-species nitrifying cultures under carbon-limited conditions disrupted biofilm formation and caused the dispersal of pre-formed biofilms. This dispersal effect was not observed when an organic carbon source, glucose, was included in the medium. Interestingly, inhibition of nitrification activity of these mixed-species biofilms in the presence of added glucose resulted in increased total biofilm formation compared to controls without the addition of nitrification inhibitors, or with only glucose added. This suggests that active AOB partially suppress or limit the overall growth of the heterotrophic bacteria. The experimental model developed here provides evidence that ammonia-oxidising bacteria (AOB) are involved in both the formation and maintenance of multi-species biofilm communities. The results demonstrate that the activity of the AOB not only support the growth and biofilm formation of heterotrophic bacteria by providing organic carbon, but also restrict and limit total biomass in mixed community systems.
Collapse
Affiliation(s)
- Pejhman Keshvardoust
- The School of Biotechnology and Biomolecular Sciences, UNSversatile open source tool for metagenomicsW Sydney, Sydney, NSW Australia
- The Centre for Marine Bio-Innovation, UNSW Sydney, Sydney, NSW Australia
| | - Vanessa A. A. Huron
- The School of Biotechnology and Biomolecular Sciences, UNSversatile open source tool for metagenomicsW Sydney, Sydney, NSW Australia
- The Centre for Marine Bio-Innovation, UNSW Sydney, Sydney, NSW Australia
| | - Matthew Clemson
- The School of Biotechnology and Biomolecular Sciences, UNSversatile open source tool for metagenomicsW Sydney, Sydney, NSW Australia
- Rural Clinical School, UNSW Sydney, Sydney, NSW Australia
| | - Florentin Constancias
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Nicolas Barraud
- The Centre for Marine Bio-Innovation, UNSW Sydney, Sydney, NSW Australia
- Genetics of Biofilms Unit, Institut Pasteur, 25-28 Rue de Dr Roux, 75015 Paris, France
| | - Scott A. Rice
- The Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- The School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- Ithree Institute, University of Technology Sydney, UTS Faculty of Science Store, Building 1, Level 2, Thomas Street, Ultimo, NSW 2007 Australia
| |
Collapse
|
66
|
Miller DP, Fitzsimonds ZR, Lamont RJ. Metabolic Signaling and Spatial Interactions in the Oral Polymicrobial Community. J Dent Res 2019; 98:1308-1314. [PMID: 31356756 DOI: 10.1177/0022034519866440] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Oral supra- and subgingival biofilms are complex communities in which hundreds of bacteria, viruses, and fungi reside and interact. In these social environments, microbes compete and cooperate for resources, such as living space and nutrients. The metabolic activities of bacteria can transform their microenvironment and dynamically influence the fitness and growth of cohabitating organisms. Biofilm communities are temporally and spatially organized largely due to cell-to-cell communication, which promotes synergistic interactions. Metabolic interactions maintain biofilm homeostasis through mutualistic cross-feeding, metabolic syntrophy, and cross-respiration. These interactions include reciprocal metabolite exchanges that promote the growth of physiologically compatible bacteria, processive catabolism of complex substrates, and unidirectional interactions that are globally important for the polymicrobial community. Additionally, oral bacterial interactions can lead to detoxification of oxidative compounds, which will provide protection to the community at large. It has also been established that specific organisms provide terminal electron acceptors to partner species that result in a shift from fermentation to respiration, thus increasing ATP yields and improving fitness. Indeed, many interspecies relationships are multidimensional, and the net outcome can be spatially and temporally dependent. Cross-kingdom interactions also occur as oral yeast are antagonistic to some oral bacteria, while numerous mutualistic interactions contribute to yeast-bacterial colonization, fitness in the oral community, and the pathogenesis of caries. Consideration of this social environment reveals behaviors and phenotypes that are not apparent through the study of microbes in isolation. Here, we provide a comprehensive overview of the metabolic interactions that shape the oral microbial community.
Collapse
Affiliation(s)
- D P Miller
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA
| | - Z R Fitzsimonds
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA
| | - R J Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA
| |
Collapse
|
67
|
Lukumbuzya M, Schmid M, Pjevac P, Daims H. A Multicolor Fluorescence in situ Hybridization Approach Using an Extended Set of Fluorophores to Visualize Microorganisms. Front Microbiol 2019; 10:1383. [PMID: 31275291 PMCID: PMC6593226 DOI: 10.3389/fmicb.2019.01383] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/03/2019] [Indexed: 01/21/2023] Open
Abstract
Fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes is a key method for the detection of (uncultured) microorganisms in environmental and medical samples. A major limitation of standard FISH protocols, however, is the small number of phylogenetically distinct target organisms that can be detected simultaneously. In this study, we introduce a multicolor FISH approach that uses eight fluorophores with distinct spectral properties, which can unambiguously be distinguished by confocal laser scanning microscopy combined with white light laser technology. Hybridization of rRNA-targeted DNA oligonucleotide probes, which were mono-labeled with these fluorophores, to Escherichia coli cultures confirmed that the fluorophores did not affect probe melting behavior. Application of the new multicolor FISH method enabled the differentiation of seven (potentially up to eight) phylogenetically distinct microbial populations in an artificial community of mixed pure cultures (five bacteria, one archaeon, and one yeast strain) and in activated sludge from a full-scale wastewater treatment plant. In contrast to previously published multicolor FISH approaches, this method does not rely on combinatorial labeling of the same microorganisms with different fluorophores, which is prone to biases. Furthermore, images acquired by this method do not require elaborate post-processing prior to analysis. We also demonstrate that the newly developed multicolor FISH method is compatible with an improved cell fixation protocol for FISH targeting Gram-negative bacterial populations. This fixation approach uses agarose embedding during formaldehyde fixation to better preserve the three-dimensional structure of spatially complex samples such as biofilms and activated sludge flocs. The new multicolor FISH approach should be highly suitable for studying structural and functional aspects of microbial communities in virtually all types of samples that can be analyzed by conventional FISH methods.
Collapse
Affiliation(s)
- Michael Lukumbuzya
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Markus Schmid
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Petra Pjevac
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Holger Daims
- Centre for Microbiology and Environmental Systems Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria.,The Comammox Research Platform, University of Vienna, Vienna, Austria
| |
Collapse
|
68
|
Maquera Huacho PM, Rodriguez Herrero E, Verspecht T, Pauwels M, Marcantonio E, Palomari Spolidorio DM, Teughels W. Terpinen-4-ol and carvacrol affect multi-species biofilm composition. BIOFOULING 2019; 35:561-572. [PMID: 31282200 DOI: 10.1080/08927014.2019.1630386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/04/2019] [Accepted: 06/07/2019] [Indexed: 06/09/2023]
Abstract
The aim of this study was to investigate the cytotoxic activity and inhibitory effect of terpinen-4-ol (T4ol) and carvacrol against single- and multi-species biofilms. The toxicity of each compound was tested on oral keratinocytes and evaluated by XTT assay. Inhibition and eradication of single-species biofilms were analyzed by crystal violet assay and the effect on multi-species biofilm composition was evaluated by qPCR. T4ol and carvacrol did not affect the epithelial cell viability, in contrast to chlorhexidine, which showed a high cytotoxic effect. Inhibition and eradication of single-species biofilms treated with T4ol and carvacrol were observed. The same inhibitory effect was observed for multi-species biofilms, especially on periodontal pathogens. In conclusion, specific concentrations of T4ol and carvacrol without toxicity towards the epithelial cells reduced the numbers of periodontal pathogens in single- and multi-species biofilms.
Collapse
Affiliation(s)
| | - Esteban Rodriguez Herrero
- Department of Oral Health Sciences, University of Leuven & Dentistry University Hospitals Leuven , Leuven , Belgium
| | - Tim Verspecht
- Department of Oral Health Sciences, University of Leuven & Dentistry University Hospitals Leuven , Leuven , Belgium
| | - Martine Pauwels
- Department of Oral Health Sciences, University of Leuven & Dentistry University Hospitals Leuven , Leuven , Belgium
| | - Elcio Marcantonio
- Department of Oral Diagnosis and Surgery, School of Dentistry, São Paulo State University (Unesp) , Araraquara , Brazil
| | | | - Wim Teughels
- Department of Oral Health Sciences, University of Leuven & Dentistry University Hospitals Leuven , Leuven , Belgium
| |
Collapse
|
69
|
Gordon V, Bakhtiari L, Kovach K. From molecules to multispecies ecosystems: the roles of structure in bacterial biofilms. Phys Biol 2019; 16:041001. [PMID: 30913545 DOI: 10.1088/1478-3975/ab1384] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Biofilms are communities of sessile microbes that are bound to each other by a matrix made of biopolymers and proteins. Spatial structure is present in biofilms on many lengthscales. These range from the nanometer scale of molecular motifs to the hundred-micron scale of multicellular aggregates. Spatial structure is a physical property that impacts the biology of biofilms in many ways. The molecular structure of matrix components controls their interaction with each other (thereby impacting biofilm mechanics) and with diffusing molecules such as antibiotics and immune factors (thereby impacting antibiotic tolerance and evasion of the immune system). The size and structure of multicellular aggregates, combined with microbial consumption of growth substrate, give rise to differentiated microenvironments with different patterns of metabolism and gene expression. Spatial association of more than one species can benefit one or both species, while distances between species can both determine and result from the transport of diffusible factors between species. Thus, a widespread theme in the biological importance of spatial structure in biofilms is the effect of structure on transport. We survey what is known about this and other effects of spatial structure in biofilms, from molecules up to multispecies ecosystems. We conclude with an overview of what experimental approaches have been developed to control spatial structure in biofilms and how these and other experiments can be complemented with computational work.
Collapse
Affiliation(s)
- Vernita Gordon
- Department of Physics, University of Texas at Austin, Austin TX 78712, United States of America. Center for Nonlinear Dynamics, University of Texas at Austin, Austin TX 78712, United States of America. Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin TX 78712, United States of America. Author to whom any correspondence should be addressed
| | | | | |
Collapse
|
70
|
Fine DH, Patil AG, Velusamy SK. Aggregatibacter actinomycetemcomitans ( Aa) Under the Radar: Myths and Misunderstandings of Aa and Its Role in Aggressive Periodontitis. Front Immunol 2019; 10:728. [PMID: 31040843 PMCID: PMC6476972 DOI: 10.3389/fimmu.2019.00728] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 03/19/2019] [Indexed: 11/23/2022] Open
Abstract
Aggregatibacter actinomycetemcomitans (Aa) is a low-abundance Gram-negative oral pathobiont that is highly associated with a silent but aggressive orphan disease that results in periodontitis and tooth loss in adolescents of African heritage. For the most part Aa conducts its business by utilizing strategies allowing it to conceal itself below the radar of the host mucosal immune defense system. A great deal of misinformation has been conveyed with respect to Aa biology in health and disease. The purpose of this review is to present misconceptions about Aa and the strategies that it uses to colonize, survive, and evade the host. In the process Aa manages to undermine host mucosal defenses and contribute to disease initiation. This review will present clinical observational, molecular, and interventional studies that illustrate genetic, phenotypic, and biogeographical tactics that have been recently clarified and demonstrate how Aa survives and suppresses host mucosal defenses to take part in disease pathogenesis. At one point in time Aa was considered to be the causative agent of Localized Aggressive Periodontitis. Currently, it is most accurate to look at Aa as a community activist and necessary partner of a pathogenic consortium that suppresses the initial host response so as to encourage overgrowth of its partners. The data for Aa's activist role stems from molecular genetic studies complemented by experimental animal investigations that demonstrate how Aa establishes a habitat (housing), nutritional sustenance in that habitat (food), and biogeographical mobilization and/or relocation from its initial habitat (transportation). In this manner Aa can transfer to a protected but vulnerable domain (pocket or sulcus) where its community activism is most useful. Aa's “strategy” includes obtaining housing, food, and transportation at no cost to its partners challenging the economic theory that “there ain't no such thing as a free lunch.” This “strategy” illustrates how co-evolution can promote Aa's survival, on one hand, and overgrowth of community members, on the other, which can result in local host dysbiosis and susceptibility to infection.
Collapse
Affiliation(s)
- Daniel H Fine
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, United States
| | - Amey G Patil
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, United States
| | - Senthil K Velusamy
- Department of Oral Biology, Rutgers School of Dental Medicine, Newark, NJ, United States
| |
Collapse
|
71
|
Aggregatibacter actinomycetemcomitans mediates protection of Porphyromonas gingivalis from Streptococcus sanguinis hydrogen peroxide production in multi-species biofilms. Sci Rep 2019; 9:4944. [PMID: 30894650 PMCID: PMC6426879 DOI: 10.1038/s41598-019-41467-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/06/2019] [Indexed: 01/10/2023] Open
Abstract
Mixed species biofilms are shaped and influenced by interactions between species. In the oral cavity, dysbiosis of the microbiome leads to diseases such as periodontitis. Porphyromonas gingivalis is a keystone pathogen of periodontitis. In this study, we showed that polymicrobial biofilm formation promoted the tolerance of Porphyromonas gingivalis to oxidative stress under micro-aerobic conditions. The presence of Streptococcus sanguinis, an oral commensal bacterium, inhibited the survival of P. gingivalis in dual-species biofilms via the secretion of hydrogen peroxide (H2O2). Interestingly, this repression could be attenuated by the presence of Aggregatibacter actinomycetemcomitans in tri-species biofilms. It was also shown that the katA gene, encoding a cytoplasmic catalase in A. actinomycetemcomitans, was responsible for the reduction of H2O2 produced by S. sanguinis, which consequently increased the biomass of P. gingivalis in tri-species biofilms. Collectively, these findings reveal that polymicrobial interactions play important roles in shaping bacterial community in biofilm. The existence of catalase producers may support the colonization of pathogens vulnerable to H2O2, in the oral cavity. The catalase may be a potential drug target to aid in the prevention of periodontitis.
Collapse
|
72
|
Miller DP, Lamont RJ. Signaling Systems in Oral Bacteria. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1197:27-43. [PMID: 31732932 DOI: 10.1007/978-3-030-28524-1_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The supra- and subgingival plaque biofilm communities of plaque are composed of hundreds of different microbes. These communities are spatially and temporally structured, largely due to cell-cell communications that coordinate synergistic interactions, and intracellular signaling systems to sense changes in the surrounding environment. Homeostasis is maintained through metabolic communication, mutualistic cross-feeding, and cross-respiration. These nutritional symbioses can reciprocally influence the local microenvironments by altering the pH and by detoxifying oxidative compounds. Signal transduction mechanisms include two-component systems, tyrosine phosphorelays, quorum sensing systems, and cyclic nucleotide secondary messengers. Signaling converges on transcriptional programs and can result in synergistic or antagonistic interbacterial interactions that sculpt community development. The sum of all these interactions can be a well-organized polymicrobial community that remains in homeostasis with the host, or a dysbiotic community that provokes pathogenic responses in the host.
Collapse
Affiliation(s)
- Daniel P Miller
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, KY, USA.
| |
Collapse
|
73
|
Taran O, Patel V, Lynn DG. Small molecule reaction networks that model the ROS dynamics of the rhizosphere. Chem Commun (Camb) 2019; 55:3602-3605. [DOI: 10.1039/c8cc08940j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Molecules released by plants and bacteria form complex abiotic reaction diffusion networks that might regulate the ROS dynamics along the roots of the plants.
Collapse
Affiliation(s)
- Olga Taran
- Departments of Chemistry and Biology
- Emory University
- USA
| | - Vraj Patel
- Departments of Chemistry and Biology
- Emory University
- USA
| | - David G. Lynn
- Departments of Chemistry and Biology
- Emory University
- USA
| |
Collapse
|
74
|
Regulation of Biofilm Aging and Dispersal in Bacillus subtilis by the Alternative Sigma Factor SigB. J Bacteriol 2018; 201:JB.00473-18. [PMID: 30396900 DOI: 10.1128/jb.00473-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 10/25/2018] [Indexed: 11/20/2022] Open
Abstract
Bacterial biofilms are important in natural settings, biotechnology, and medicine. However, regulation of biofilm development and its persistence in different niches is complex and only partially understood. One key step during the biofilm life cycle is dispersal, when motile cells abandon the mature biofilm to spread out and colonize new niches. Here, we show that in the model bacterium Bacillus subtilis the general stress transcription factor SigB is essential for halting detrimental overgrowth of mature biofilm and for triggering dispersal when nutrients become limited. Specifically, SigB-deficient biofilms were larger than wild-type biofilms but exhibited accelerated cell death, significantly greater sensitivity to different stresses, and reduced dispersal. Interestingly, the signal detected by SigB to limit biofilm growth was transduced through the RsbP-dependent metabolic arm of the SigB regulatory cascade, which in turn positively controlled expression of SinR, the master regulator of biofilm formation and cell motility. This novel SigB-SinR regulatory circuit might be important in controlling the fitness of biofilms (either beneficial or harmful) in diverse environments.IMPORTANCE Biofilms are crucial for bacterial survival, adaptation, and dissemination in natural, industrial, and medical systems. Sessile cells embedded in the self-produced extracellular matrix of the biofilm benefit from a division of labor and are protected from environmental insults. However, as the biofilm ages, cells become stressed because of overcrowding, starvation, and accumulation of waste products. How does the sessile biofilm community sense and respond to stressful conditions? Here, we show that in Bacillus subtilis, the transcription factors SigB and SinR control whether cells remain in or leave a biofilm when metabolic conditions become unfavorable. This novel SigB-SinR regulatory circuit might be important for controlling the fitness of biofilms (either beneficial or harmful) in diverse environments.
Collapse
|
75
|
Darch SE, Koley D. Quantifying microbial chatter: scanning electrochemical microscopy as a tool to study interactions in biofilms. Proc Math Phys Eng Sci 2018; 474:20180405. [PMID: 30602930 DOI: 10.1098/rspa.2018.0405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 11/09/2018] [Indexed: 12/12/2022] Open
Abstract
Bacteria are often found in their natural habitats as spatially organized biofilm communities. While it is clear from recent work that the ability to organize into precise spatial structures is important for fitness of microbial communities, a significant gap exists in our understanding regarding the mechanisms bacteria use to adopt such physical distributions. Bacteria are highly social organisms that interact, and it is these interactions that have been proposed to be critical for establishing spatially structured communities. A primary means by which bacteria interact is via small, diffusible molecules including dedicated signals and metabolic by-products; however, quantitatively monitoring the production of these molecules in time and space with the micron-scale resolution required has been challenging. In this perspective, scanning electrochemical microscopy (SECM) is discussed as a powerful tool to study microbe-microbe interactions through the detection of small redox-active molecules. We highlight SECM as a means to quantify and spatially resolve the chemical mediators of bacterial interactions and begin to elucidate the mechanisms used by bacteria to regulate the emergent properties of biofilms.
Collapse
Affiliation(s)
- Sophie E Darch
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.,Emory-Children's Cystic Fibrosis Center, Atlanta, GA, USA
| | - Dipankar Koley
- Department of Chemistry, Oregon State University, Corvallis, OR, USA
| |
Collapse
|
76
|
Abstract
The dynamic and polymicrobial oral microbiome is a direct precursor of diseases such as dental caries and periodontitis, two of the most prevalent microbially induced disorders worldwide. Distinct microenvironments at oral barriers harbour unique microbial communities, which are regulated through sophisticated signalling systems and by host and environmental factors. The collective function of microbial communities is a major driver of homeostasis or dysbiosis and ultimately health or disease. Despite different aetiologies, periodontitis and caries are each driven by a feedforward loop between the microbiota and host factors (inflammation and dietary sugars, respectively) that favours the emergence and persistence of dysbiosis. In this Review, we discuss current knowledge and emerging mechanisms governing oral polymicrobial synergy and dysbiosis that have both enhanced our understanding of pathogenic mechanisms and aided the design of innovative therapeutic approaches for oral diseases.
Collapse
Affiliation(s)
- Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA.
| | - Hyun Koo
- Department of Orthodontics and Divisions of Pediatric Dentistry and Community Oral Health, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - George Hajishengallis
- Department of Microbiology, Penn Dental Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
77
|
Mutha NVR, Mohammed WK, Krasnogor N, Tan GYA, Choo SW, Jakubovics NS. Transcriptional responses of Streptococcus gordonii
and Fusobacterium nucleatum
to coaggregation. Mol Oral Microbiol 2018; 33:450-464. [DOI: 10.1111/omi.12248] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 09/14/2018] [Accepted: 10/12/2018] [Indexed: 12/30/2022]
Affiliation(s)
- Naresh V. R. Mutha
- Institute of Biological Sciences, Faculty of Science; University of Malaya; Kuala Lumpur Malaysia
| | - Waleed K. Mohammed
- School of Dental Sciences; Centre for Oral Health Research, Newcastle University; Newcastle upon Tyne UK
- Department of Basic Science, College of Dentistry; University of Anbar; Anbar Iraq
| | - Natalio Krasnogor
- Interdisciplinary Computing and Complex Biosystems (ICOS) Research Group, School of Computing; Newcastle University; Newcastle upon Tyne UK
| | - Geok Y. A. Tan
- Institute of Biological Sciences, Faculty of Science; University of Malaya; Kuala Lumpur Malaysia
| | - Siew W. Choo
- Department of Biological Sciences; Xi’an Jiaotong-Liverpool University, Suzhou Dushu Lake Science and Education Innovation District; Suzhou China
- Suzhou Genome Centre (SGC); Health Technologies University Research Centre (HT-URC), Xi’an Jiaotong-Liverpool University, Suzhou Dushu Lake Science and Education Innovation District; Suzhou China
| | - Nicholas S. Jakubovics
- School of Dental Sciences; Centre for Oral Health Research, Newcastle University; Newcastle upon Tyne UK
| |
Collapse
|
78
|
Marsh PD, Zaura E. Dental biofilm: ecological interactions in health and disease. J Clin Periodontol 2018; 44 Suppl 18:S12-S22. [PMID: 28266111 DOI: 10.1111/jcpe.12679] [Citation(s) in RCA: 244] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND The oral microbiome is diverse and exists as multispecies microbial communities on oral surfaces in structurally and functionally organized biofilms. AIM To describe the network of microbial interactions (both synergistic and antagonistic) occurring within these biofilms and assess their role in oral health and dental disease. METHODS PubMed database was searched for studies on microbial ecological interactions in dental biofilms. The search results did not lend themselves to systematic review and have been summarized in a narrative review instead. RESULTS Five hundred and forty-seven original research articles and 212 reviews were identified. The majority (86%) of research articles addressed bacterial-bacterial interactions, while inter-kingdom microbial interactions were the least studied. The interactions included physical and nutritional synergistic associations, antagonism, cell-to-cell communication and gene transfer. CONCLUSIONS Oral microbial communities display emergent properties that cannot be inferred from studies of single species. Individual organisms grow in environments they would not tolerate in pure culture. The networks of multiple synergistic and antagonistic interactions generate microbial inter-dependencies and give biofilms a resilience to minor environmental perturbations, and this contributes to oral health. If key environmental pressures exceed thresholds associated with health, then the competitiveness among oral microorganisms is altered and dysbiosis can occur, increasing the risk of dental disease.
Collapse
Affiliation(s)
- P D Marsh
- Department of Oral Biology, School of Dentistry, University of Leeds, Leeds, UK
| | - Egija Zaura
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands
| |
Collapse
|
79
|
Ramenzoni LL, Zuellig RA, Hussain A, Lehmann R, Heumann C, Attin T, Schmidlin PR. Bacterial supernatants elevate glucose-dependent insulin secretion in rat pancreatic INS-1 line and islet β-cells via PI3K/AKT signaling. Mol Cell Biochem 2018; 452:17-27. [PMID: 30039349 PMCID: PMC6373304 DOI: 10.1007/s11010-018-3408-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2017] [Accepted: 07/13/2018] [Indexed: 01/04/2023]
Abstract
Diabetes and periodontitis are considered associated chronic diseases, and hyperinsulinemia in prediabetes has been shown to be present in normoglycemic animals with periodontitis. As periodontal bacterial species are significant sources of endotoxemia and may directly stimulate insulin secretion, we hypothesized that increased bacterial virulence may exert an adverse effect on rat pancreatic β-cell function via PI3K/AKT signaling. INS-1 cells and isolated pancreatic islets were cultured separately with the following supernatants: Streptococcus anginosus, Streptococcus mutans, Fusobacterium nucleatum, Prevotella intermedia, Porphyromonas gingivalis (P.g), and Treponema denticola (T.d). Supernatants were purified from single bacterial cultures and prepared at different dilutions (100 pg/ml, 50 ng/ml, 200 ng/ml, and 500 ng/ml) to challenge INS-1 and islets. Gene expression (IL-1β, TNFα, IL-6, TLR2, TLR4, Ins1, and Ins2) and insulin secretion were measured. The results showed upregulation of gene expression up to 5.5-fold, not only as a result of the different dilutions used, but also due to bacterial virulence (p < 0.05). P.g and T.d supernatants demonstrated an increase in insulin secretion to fivefold at hypo- and hyperglycemia, yet stimulation from hypo- to hyperglycemia stays in the same ratio. Activation of TLR4/PI3K/AKT signaling by supernatants in INS-1 cells resulted in increased IL-1β, TNFα, IL-6 gene expression levels, and AKT phosphorylation, which were abolished by TLR4 and PI3K/AKT signaling inhibitor. We demonstrated that bacterial supernatants derived from gram-negative species increasingly stimulate insulin secretion in β-cells and TLR4 may promote inflammation by activating the PI3K/AKT signaling pathway to induce pro-inflammatory molecules. Bacterial species, depending on their virulence, appear to play a role in the relationship between periodontitis and prediabetes by promoting insulin resistance and β-cell compensatory response.
Collapse
Affiliation(s)
- Liza L Ramenzoni
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Richard A Zuellig
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Abbas Hussain
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Roger Lehmann
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Rämistrasse 100, 8091, Zurich, Switzerland
| | - Christian Heumann
- Department for Statistics, Ludwig-Maximilians-University Munich, Theresienstrasse 39/I, 80333, Munich, Germany
| | - Thomas Attin
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland
| | - Patrick R Schmidlin
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland.
| |
Collapse
|
80
|
Redanz S, Cheng X, Giacaman RA, Pfeifer CS, Merritt J, Kreth J. Live and let die: Hydrogen peroxide production by the commensal flora and its role in maintaining a symbiotic microbiome. Mol Oral Microbiol 2018; 33:337-352. [PMID: 29897662 DOI: 10.1111/omi.12231] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2018] [Indexed: 02/05/2023]
Abstract
The majority of commensal oral streptococci are able to generate hydrogen peroxide (H2 O2 ) during aerobic growth, which can diffuse through the cell membrane and inhibit competing species in close proximity. Competing H2 O2 production is mainly dependent upon the pyruvate oxidase SpxB, and to a lesser extent the lactate oxidase LctO, both of which are important for energy generation in aerobic environments. Several studies point to a broad impact of H2 O2 production in the oral environment, including a potential role in biofilm homeostasis, signaling, and interspecies interactions. Here, we summarize the current research regarding oral streptococcal H2 O2 generation, resistance mechanisms, and the ecological impact of H2 O2 production. We also discuss the potential therapeutic utility of H2 O2 for the prevention/treatment of dysbiotic diseases as well as its potential role as a biomarker of oral health.
Collapse
Affiliation(s)
- Sylvio Redanz
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
| | - Xingqun Cheng
- The State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China.,The Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Rodrigo A Giacaman
- Cariology Unit, Department of Oral Rehabilitation and Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), University of Talca, Talca, Chile
| | - Carmen S Pfeifer
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
| | - Justin Merritt
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
| | - Jens Kreth
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, Oregon
| |
Collapse
|
81
|
Estrela S, Brown SP. Community interactions and spatial structure shape selection on antibiotic resistant lineages. PLoS Comput Biol 2018; 14:e1006179. [PMID: 29927925 PMCID: PMC6013025 DOI: 10.1371/journal.pcbi.1006179] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Accepted: 05/06/2018] [Indexed: 01/21/2023] Open
Abstract
Polymicrobial interactions play an important role in shaping the outcome of antibiotic treatment, yet how multispecies communities respond to antibiotic assault is still little understood. Here we use an individual-based simulation model of microbial biofilms to investigate how competitive and mutualistic interactions between an antibiotic-resistant and a susceptible strain (or species) influence the two-lineage community response to antibiotic exposure. Our model predicts that while increasing competition and antibiotics leads to increasing competitive release of the antibiotic-resistant strain, hitting a mutualistic community of cross-feeding species with antibiotics leads to a mutualistic suppression effect where both susceptible and resistant species are harmed. We next show that the impact of antibiotics is further governed by emergent spatial feedbacks within communities. Mutualistic cross-feeding communities can rescue susceptible members by subsidizing their growth inside the biofilm despite lack of access to the nutrient-rich and high-antibiotic growing front. Moreover, we show that antibiotic detoxification by resistant cells can protect nearby susceptible cells, but such cross-protection is more effective in mutualistic communities because mutualism drives mixing of resistant and susceptible cells. In contrast, competition leads to segregation, which ultimately prevents susceptible cells to profit from detoxification. Understanding how the interplay between microbial metabolic interactions and community spatial structuring shapes the outcome of antibiotic treatment can be key to effectively leverage the power of antibiotics and promote microbiome health. Pathogens -microorganisms that make us sick- often live within dynamic and complex multispecies communities, where they may not only compete for limiting resources but also exchange beneficial resources or services with other resident species. While antibiotics are commonly used to get rid of such harmful microbes, the community-wide effects of antibiotic treatment and its consequences for antibiotic resistance are still not well understood. How do competitive or mutually beneficial interactions between antibiotic resistant and susceptible species influence community resistance to antibiotics? Here we investigate this question using a computational model. We find that antibiotic exposure favours the resistant lineage when resistant and susceptible strains are competitors but harms both types when they are mutualists. With antibiotic-detoxifying resistant cells, cross-protection of susceptible cells is more effective in mutualistic communities because mutualism drives mixing of susceptible and resistant cells. In contrast, competition leads to their segregation, precluding susceptible cells to profit from their competitor’s local detoxification. Our findings highlight that knowing not only what species are present but also how they interact with each other and arrange themselves in space is central to understanding antibiotic resistance and to informing the development of strategies that promote microbiome health.
Collapse
Affiliation(s)
- Sylvie Estrela
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, United States of America
- * E-mail:
| | - Sam P. Brown
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| |
Collapse
|
82
|
Abstract
Quorum sensing is a communication system that allows bacteria to coordinate their activities, and these systems are critical for virulence in several bacteria, including Pseudomonas aeruginosa. There is a significant gap in knowledge about how quorum sensing proceeds during infection, particularly how spatial organization of the infecting microbial community impacts signaling. Using a model that recapitulates the biogeographical properties of P. aeruginosa infection of the cystic fibrosis lung, we discovered that communication primarily occurs within P. aeruginosa aggregates and that communication between aggregates is only observed for very large aggregates containing ≥5,000 cells. This study identifies a critical role for spatial distribution and bacterial phenotypic heterogeneity in bacterial signaling during infection, and provides a platform for future ecological and evolutionary studies. Quorum sensing (QS) is a bacterial communication system that involves production and sensing of extracellular signals. In laboratory models, QS allows bacteria to monitor and respond to their own cell density and is critical for fitness. However, how QS proceeds in natural, spatially structured bacterial communities is not well understood, which significantly hampers our understanding of the emergent properties of natural communities. To address this gap, we assessed QS signaling in the opportunistic pathogen Pseudomonas aeruginosa in a cystic fibrosis (CF) lung infection model that recapitulates the biogeographical aspects of the natural human infection. In this model, P. aeruginosa grows as spatially organized, highly dense aggregates similar to those observed in the human CF lung. By combining this natural aggregate system with a micro-3D–printing platform that allows for confinement and precise spatial positioning of P. aeruginosa aggregates, we assessed the impact of aggregate size and spatial positioning on both intra- and interaggregate signaling. We discovered that aggregates containing ∼2,000 signal-producing P. aeruginosa were unable to signal neighboring aggregates, while those containing ≥5,000 cells signaled aggregates as far away as 176 µm. Not all aggregates within this “calling distance” responded, indicating that aggregates have differential sensitivities to signal. Overexpression of the signal receptor increased aggregate sensitivity to signal, suggesting that the ability of aggregates to respond is defined in part by receptor levels. These studies provide quantitative benchmark data for the impact of spatial arrangement and phenotypic heterogeneity on P. aeruginosa signaling in vivo.
Collapse
|
83
|
Schneider B, Weigel W, Sztukowska M, Demuth DR. Identification and functional characterization of type II toxin/antitoxin systems in Aggregatibacter actinomycetemcomitans. Mol Oral Microbiol 2018; 33:224-233. [PMID: 29319934 PMCID: PMC5969271 DOI: 10.1111/omi.12215] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2018] [Indexed: 11/30/2022]
Abstract
Type II toxin/antitoxin (TA) systems contribute to the formation of persister cells and biofilm formation for many organisms. Aggregatibacter actinomycetemcomitans thrives in the complex oral microbial community subjected to continual environmental flux. Little is known regarding the presence and function of type II TA systems in this organism or their contribution to adaptation and persistence in the biofilm. We identified 11 TA systems that are conserved across all seven serotypes of A. actinomycetemcomitans and represent the RelBE, MazEF and HipAB families of type II TA systems. The systems selectively responded to various environmental conditions that exist in the oral cavity. Two putative RelBE‐like TA systems, D11S_1194‐1195 and D11S_1718‐1719 were induced in response to low pH and deletion of D11S_1718‐1719 significantly reduced metabolic activity of stationary phase A. actinomycetemcomitans cells upon prolonged exposure to acidic conditions. The deletion mutant also exhibited reduced biofilm biomass when cultured under acidic conditions. The D11S_1194 and D11S_1718 toxin proteins inhibited in vitro translation of dihydrofolate reductase (DHFR) and degraded ribosome‐associated, but not free, MS2 virus RNA. In contrast, the corresponding antitoxins (D11S_1195 and D11S_1719), or equimolar mixtures of toxin and antitoxin, had no effect on DHFR production or RNA degradation. Together, these results suggest that D11S_1194‐1195 and D11S_1718‐1719 are RelBE‐like type II TA systems that are activated under acidic conditions and may function to cleave ribosome‐associated mRNA to inhibit translation in A. actinomycetemcomitans. In vivo, these systems may facilitate A. actinomycetemcomitans adaptation and persistence in acidic local environments in the dental biofilm.
Collapse
Affiliation(s)
- B Schneider
- Department of Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, KY, USA
| | - W Weigel
- Department of Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, KY, USA
| | - M Sztukowska
- Department of Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, KY, USA
| | - D R Demuth
- Department of Oral Immunology and Infectious Disease, University of Louisville School of Dentistry, Louisville, KY, USA
| |
Collapse
|
84
|
Genomic integration and expression of the Aggregatibacter actinomycetemcomitans catalase gene in Aggregatibacter aphrophilus. Arch Oral Biol 2018; 86:116-122. [DOI: 10.1016/j.archoralbio.2017.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 11/30/2017] [Accepted: 12/03/2017] [Indexed: 11/23/2022]
|
85
|
The spatial and metabolic basis of colony size variation. ISME JOURNAL 2018; 12:669-680. [PMID: 29367665 PMCID: PMC5864198 DOI: 10.1038/s41396-017-0038-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 08/11/2017] [Accepted: 08/14/2017] [Indexed: 11/15/2022]
Abstract
Spatial structure impacts microbial growth and interactions, with ecological and evolutionary consequences. It is therefore important to quantitatively understand how spatial proximity affects interactions in different environments. We tested how proximity influences colony size when either Escherichia coli or Salmonella enterica are grown on various carbon sources. The importance of colony location changed with species and carbon source. Spatially explicit, genome-scale metabolic modeling recapitulated observed colony size variation. Competitors that determine territory size, according to Voronoi diagrams, were the most important drivers of variation in colony size. However, the relative importance of different competitors changed through time. Further, the effect of location increased when colonies took up resources quickly relative to the diffusion of limiting resources. These analyses made it apparent that the importance of location was smaller than expected for experiments with S. enterica growing on glucose. The accumulation of toxic byproducts appeared to limit the growth of large colonies and reduced variation in colony size. Our work provides an experimentally and theoretically grounded understanding of how location interacts with metabolism and diffusion to influence microbial interactions.
Collapse
|
86
|
Abstract
Removable dentures are worn by 20% of the UK population and two thirds of these individuals have denture stomatitis. Poor oral hygiene is commonplace among this group, as is smoking and xerostomia, which also contribute to the development of denture stomatitis. A complex polymicrobial biofilm is able to proliferate on the surface of denture materials and matures to form visible denture plaque. This denture plaque biofilm stimulates a local inflammatory process that is detectable clinically as erythema, and hyperplasia. Systemically, denture plaque represents a potential risk factor for systemic disease, in particular aspiration pneumonia. Respiratory pathogens have been detected in the denture plaque and overnight denture wear has been linked to an increased risk of aspiration pneumonia. There is a general lack of evidence on the adequate management of denture stomatitis and we present a protocol for use in the primary care setting.
Collapse
|
87
|
|
88
|
Whiteley M, Diggle SP, Greenberg EP. Progress in and promise of bacterial quorum sensing research. Nature 2017; 551:313-320. [PMID: 29144467 PMCID: PMC5870893 DOI: 10.1038/nature24624] [Citation(s) in RCA: 668] [Impact Index Per Article: 95.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 10/09/2017] [Indexed: 12/13/2022]
Abstract
This Review highlights how we can build upon the relatively new and rapidly developing field of research into bacterial quorum sensing (QS). We now have a depth of knowledge about how bacteria use QS signals to communicate with each other and to coordinate their activities. In recent years there have been extraordinary advances in our understanding of the genetics, genomics, biochemistry, and signal diversity of QS. We are beginning to understand the connections between QS and bacterial sociality. This foundation places us at the beginning of a new era in which researchers will be able to work towards new medicines to treat devastating infectious diseases, and use bacteria to understand the biology of sociality.
Collapse
Affiliation(s)
- Marvin Whiteley
- Department of Molecular Biosciences, Institute of Cellular and Molecular Biology, John Ring LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, TX USA
| | - Stephen P. Diggle
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA USA
| | - E. Peter Greenberg
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA USA, Guangdong Innovative and Entrepreneurial Research Team of Sociomicrobiology Basic Science and Frontier Technology, South China Agricultural University, Guangzhou, China
| |
Collapse
|
89
|
Rice SA. Interactions between microbial community members. ENVIRONMENTAL MICROBIOLOGY REPORTS 2017; 9:471-473. [PMID: 28772026 DOI: 10.1111/1758-2229.12571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Scott A Rice
- The Singapore Centre for Environmental Life Sciences Engineering and the School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- The ithree institute, The University of Technology Sydney, Sydney, NSW, Australia
| |
Collapse
|
90
|
Fuller AW, Young P, Pierce BD, Kitson-Finuff J, Jain P, Schneider K, Lazar S, Taran O, Palmer AG, Lynn DG. Redox-mediated quorum sensing in plants. PLoS One 2017; 12:e0182655. [PMID: 28902851 PMCID: PMC5597120 DOI: 10.1371/journal.pone.0182655] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 07/22/2017] [Indexed: 11/19/2022] Open
Abstract
The rhizosphere, the narrow zone of soil around plant roots, is a complex network of interactions between plants, bacteria, and a variety of other organisms. The absolute dependence on host-derived signals, or xenognosins, to regulate critical developmental checkpoints for host commitment in the obligate parasitic plants provides a window into the rhizosphere's chemical dynamics. These sessile intruders use H2O2 in a process known as semagenesis to chemically modify the mature root surfaces of proximal host plants and generate p-benzoquinones (BQs). The resulting redox-active signaling network regulates the spatial and temporal commitments necessary for host attachment. Recent evidence from non-parasites, including Arabidopsis thaliana, establishes that reactive oxygen species (ROS) production regulates similar redox circuits related to root recognition, broadening xenognosins' role beyond the parasites. Here we compare responses to the xenognosin dimethoxybenzoquinone (DMBQ) between the parasitic plant Striga asiatica and the non-parasitic A. thaliana. Exposure to DMBQ simulates the proximity of a mature root surface, stimulating an increase in cytoplasmic Ca2+ concentration in both plants, but leads to remarkably different phenotypic responses in the parasite and non-parasite. In S. asiatica, DMBQ induces development of the host attachment organ, the haustorium, and decreases ROS production at the root tip, while in A. thaliana, ROS production increases and further growth of the root tip is arrested. Obstruction of Ca2+ channels and the addition of antioxidants both lead to a decrease in the DMBQ response in both parasitic and non-parasitic plants. These results are consistent with Ca2+ regulating the activity of NADPH oxidases, which in turn sustain the autocatalytic production of ROS via an external quinone/hydroquinone redox cycle. Mechanistically, this chemistry is similar to black and white photography with the emerging dynamic reaction-diffusion network laying the foundation for the precise temporal and spatial control underlying rhizosphere architecture.
Collapse
Affiliation(s)
- Alexandra W. Fuller
- Departments of Biology and Chemistry, Emory University, Atlanta, GA, United States of America
| | - Phoebe Young
- Departments of Biology and Chemistry, Emory University, Atlanta, GA, United States of America
| | - B. Daniel Pierce
- Departments of Biology and Chemistry, Emory University, Atlanta, GA, United States of America
- Gottwald Science Center, University of Richmond, Richmond, VA, United States of America
| | - Jamie Kitson-Finuff
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, United States of America
| | - Purvi Jain
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, United States of America
| | - Karl Schneider
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, United States of America
| | - Stephen Lazar
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, United States of America
| | - Olga Taran
- Departments of Biology and Chemistry, Emory University, Atlanta, GA, United States of America
| | - Andrew G. Palmer
- Department of Biological Sciences, Florida Institute of Technology, Melbourne, FL, United States of America
| | - David G. Lynn
- Departments of Biology and Chemistry, Emory University, Atlanta, GA, United States of America
| |
Collapse
|
91
|
Keke Z, Xuedong Z, Xin X. [The origin of hydrogen peroxide in oral cavity and its role in oral microecology balance]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2017; 35:215-220. [PMID: 28682556 DOI: 10.7518/hxkq.2017.02.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hydrogen peroxide, an important antimicrobial agent in oral cavity, plays a significant role in the balance of oral microecology. At the early stage of biofilm formation, about 80% of the detected initial colonizers belong to the genus Streptococcus. These oral streptococci use different oxidase to produce hydrogen peroxide. Recent studies showed that the produced hydrogen peroxide plays a critical role in modulating oral microecology. Hydrogen peroxide modulates biofilm development attributed to its growth inhibitory nature. Hydrogen peroxide production is closely associated with extracellular DNA(eDNA) release from microbe and the development of its competent cell which are critical for biofilm development and also serves as source for horizontal gene transfer. Microbe also can reduce the damage to themselves through several detoxification mechanisms. Moreover, hydrogen peroxide is also involved in the regulation of interactions between oral microorganisms and host. Taken together, hydrogen peroxide is an imperative ecological factor that contributes to the microbial equilibrium in the oral cavity. Here we will give a brief review of both the origin and the function in the oral microecology balance of hydrogen peroxide.
Collapse
Affiliation(s)
- Zhang Keke
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Zhou Xuedong
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Xu Xin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| |
Collapse
|
92
|
Gong H, Shi Y, Xiao X, Cao P, Wu C, Tao L, Hou D, Wang Y, Zhou L. Alterations of microbiota structure in the larynx relevant to laryngeal carcinoma. Sci Rep 2017; 7:5507. [PMID: 28710395 PMCID: PMC5511217 DOI: 10.1038/s41598-017-05576-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/31/2017] [Indexed: 02/07/2023] Open
Abstract
The microbial communities that inhabit the laryngeal mucosa build stable microenvironments and have the potential to influence the health of the human throat. However, the associations between the microbiota structure and laryngeal carcinoma remain uncertain. Here, we explored this question by comparing the laryngeal microbiota structure in laryngeal cancer patients with that in control subjects with vocal cord polyps through high-throughput pyrosequencing. Overall, the genera Streptococcus, Fusobacterium, and Prevotella were prevalent bacterial populations in the laryngeal niche. Tumor tissue samples and normal tissues adjacent to the tumor sites (NATs) were collected from 31 laryngeal cancer patients, and the bacterial communities in laryngeal cancer patients were compared with control samples from 32 subjects. A comparison of the laryngeal communities in the tumor tissues and the NATs showed higher α-diversity in cancer patients than in control subjects, and the relative abundances of seven bacterial genera differed among the three groups of samples. Furthermore, the relative abundances of ten bacterial genera in laryngeal cancer patients differed substantially from those in control subjects. These findings indicate that the laryngeal microbiota profiles are altered in laryngeal cancer patients, suggesting that a disturbance of the microbiota structure might be relevant to laryngeal cancer.
Collapse
Affiliation(s)
- Hongli Gong
- Shanghai Key Clinical Disciplines of Otorhinolaryngology, Department of Otorhinolaryngology, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
| | - Yi Shi
- Department of Clinical Laboratory, Shanghai Pudong Hospital, Fudan University Pudong Medical Center, 2800 Gongwei Road, Shanghai, 201399, China.
| | - Xiyan Xiao
- Shanghai Key Clinical Disciplines of Otorhinolaryngology, Department of Otorhinolaryngology, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
| | - Pengyu Cao
- Shanghai Key Clinical Disciplines of Otorhinolaryngology, Department of Otorhinolaryngology, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
| | - Chunping Wu
- Shanghai Key Clinical Disciplines of Otorhinolaryngology, Department of Otorhinolaryngology, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
| | - Lei Tao
- Shanghai Key Clinical Disciplines of Otorhinolaryngology, Department of Otorhinolaryngology, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China
| | - Dongsheng Hou
- Shanghai Key Laboratory for Reproductive Medicine, Department of Histology and Embryology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China
| | - Yuezhu Wang
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Sequencing Centre, 250 Bibo Road, Shanghai, 201203, China
| | - Liang Zhou
- Shanghai Key Clinical Disciplines of Otorhinolaryngology, Department of Otorhinolaryngology, Eye, Ear, Nose, and Throat Hospital of Fudan University, 83 Fenyang Road, Shanghai, 200031, China.
| |
Collapse
|
93
|
Kreth J, Giacaman RA, Raghavan R, Merritt J. The road less traveled - defining molecular commensalism with Streptococcus sanguinis. Mol Oral Microbiol 2017; 32:181-196. [PMID: 27476770 PMCID: PMC5288394 DOI: 10.1111/omi.12170] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2016] [Indexed: 12/15/2022]
Abstract
The commensal oral microbial flora has evolved with the human host to support colonization of the various intraoral sites without triggering a significant immune response. In exchange, the commensal microbes provide critical protection against invading pathogens. The intrinsic ability of the oral flora to create a symbiotic microbial community with the host can be disturbed, selecting for the overgrowth of a dysbiotic community that can result in dental diseases, such as caries and periodontitis. Although the mechanisms of molecular pathogenesis in oral diseases are well characterized, much less is known about the molecular mechanisms used by the commensal flora to maintain oral health. Here we focus on the commensal species Streptococcus sanguinis, which is found in abundance in the early oral biofilm and is strongly correlated with oral health. Streptococcus sanguinis exhibits a variety of features that make it ideally suited as a model organism to explore the molecular basis for commensalism. As such, this review will describe our current mechanistic understanding of S. sanguinis commensalism and speculate upon its molecular traits that may be exploitable to maintain or restore oral health under conditions that would otherwise lead to disease.
Collapse
Affiliation(s)
- Jens Kreth
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, OR, USA
| | - Rodrigo A. Giacaman
- Cariology Unit, Department of Oral Rehabilitation and Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), University of Talca, Talca, Chile
| | - Rahul Raghavan
- Department of Biology and Center for Life in Extreme Environments, Portland State University, Portland, OR, USA
| | - Justin Merritt
- Department of Restorative Dentistry, Oregon Health and Science University, Portland, OR, USA
| |
Collapse
|
94
|
Abstract
Chronic polymicrobial infections are associated with increased virulence compared to monospecies infections. However, our understanding of microbial dynamics during polymicrobial infection is limited. A recent study by Limoli and colleagues (D. H. Limoli, G. B. Whitfield, T. Kitao, M. L. Ivey, M. R. Davis, Jr., et al., mBio 8:e00186-17, 2017, https://doi.org/10.1128/mBio.00186-17) provides insight into a mechanism that may contribute to the coexistence of Pseudomonas aeruginosa and Staphylococcus aureus in the cystic fibrosis (CF) lung. CF lung infections have frequently been used to investigate microbial interactions due to both the complex polymicrobial community and chronic nature of these infections. The hypothesis of Limoli et al. is that the conversion of P. aeruginosa to its mucoidy phenotype during chronic CF infection promotes coexistence by diminishing its ability to kill S. aureus Highlighting a new facet of microbial interaction between two species that are traditionally thought of as competitors, this study provides a platform for studying community assembly in a relevant infection setting.
Collapse
|
95
|
Guilhen C, Forestier C, Balestrino D. Biofilm dispersal: multiple elaborate strategies for dissemination of bacteria with unique properties. Mol Microbiol 2017; 105:188-210. [PMID: 28422332 DOI: 10.1111/mmi.13698] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2017] [Indexed: 01/22/2023]
Abstract
In most environments, microorganisms evolve in a sessile mode of growth, designated as biofilm, which is characterized by cells embedded in a self-produced extracellular matrix. Although a biofilm is commonly described as a "cozy house" where resident bacteria are protected from aggression, bacteria are able to break their biofilm bonds and escape to colonize new environments. This regulated process is observed in a wide variety of species; it is referred to as biofilm dispersal, and is triggered in response to various environmental and biological signals. The first part of this review reports the main regulatory mechanisms and effectors involved in biofilm dispersal. There is some evidence that dispersal is a necessary step between the persistence of bacteria inside biofilm and their dissemination. In the second part, an overview of the main methods used so far to study the dispersal process and to harvest dispersed bacteria was provided. Then focus was on the properties of the biofilm-dispersed bacteria and the fundamental role of the dispersal process in pathogen dissemination within a host organism. In light of the current body of knowledge, it was suggested that dispersal acts as a potent means of disseminating bacteria with enhanced colonization properties in the surrounding environment.
Collapse
Affiliation(s)
- Cyril Guilhen
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| | - Christiane Forestier
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| | - Damien Balestrino
- Laboratoire Microorganismes : Génome et Environnement, UMR CNRS 6023, Université Clermont Auvergne, Clermont Ferrand, F-63001, France
| |
Collapse
|
96
|
Phage Inhibit Pathogen Dissemination by Targeting Bacterial Migrants in a Chronic Infection Model. mBio 2017; 8:mBio.00240-17. [PMID: 28377527 PMCID: PMC5380840 DOI: 10.1128/mbio.00240-17] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The microbial communities inhabiting chronic infections are often composed of spatially organized micrometer-sized, highly dense aggregates. It has recently been hypothesized that aggregates are responsible for the high tolerance of chronic infections to host immune functions and antimicrobial therapies. Little is currently known regarding the mechanisms controlling aggregate formation and antimicrobial tolerance primarily because of the lack of robust, biologically relevant experimental systems that promote natural aggregate formation. Here, we developed an in vitro model based on chronic Pseudomonas aeruginosa infection of the cystic fibrosis (CF) lung. This model utilizes a synthetic sputum medium that readily promotes the formation of P. aeruginosa aggregates with sizes similar to those observed in human CF lung tissue. Using high-resolution imaging, we exploited this model to elucidate the life history of P. aeruginosa and the mechanisms that this bacterium utilizes to tolerate antimicrobials, specifically, bacteriophage. In the early stages of growth in synthetic sputum, planktonic cells form aggregates that increase in size over time by expansion. In later growth, migrant cells disperse from aggregates and colonize new areas, seeding new aggregates. When added simultaneously with phage, P. aeruginosa was readily killed and aggregates were unable to form. When added after initial aggregate formation, phage were unable to eliminate all of the aggregates because of exopolysaccharide production; however, seeding of new aggregates by dispersed migrants was inhibited. We propose a model in which aggregates provide a mechanism that allows P. aeruginosa to tolerate phage therapy during chronic infection without the need for genetic mutation.IMPORTANCE Bacteria in chronic infections often reside in communities composed of micrometer-sized, highly dense aggregates. A primary challenge for studying aggregates has been the lack of laboratory systems that promote natural aggregate formation in relevant environments. Here, we developed a growth medium that mimics chronic lung infection and promotes natural aggregate formation by the bacterium Pseudomonas aeruginosa High-resolution, single-cell microscopy allowed us to characterize P. aeruginosa's life history-seeding, aggregate formation, and dispersal-in this medium. Our results reveal that this bacterium readily forms aggregates that release migrants to colonize new areas. We also show that aggregates allow P. aeruginosa to tolerate therapeutic bacteriophage addition, although this treatment limits P. aeruginosa dissemination by targeting migrants.
Collapse
|
97
|
Szafrański SP, Deng ZL, Tomasch J, Jarek M, Bhuju S, Rohde M, Sztajer H, Wagner-Döbler I. Quorum sensing of Streptococcus mutans is activated by Aggregatibacter actinomycetemcomitans and by the periodontal microbiome. BMC Genomics 2017; 18:238. [PMID: 28320314 PMCID: PMC5359896 DOI: 10.1186/s12864-017-3618-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 03/10/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The oral cavity is inhabited by complex microbial communities forming biofilms that can cause caries and periodontitis. Cell-cell communication might play an important role in modulating the physiologies of individual species, but evidence so far is limited. RESULTS Here we demonstrate that a pathogen of the oral cavity, Aggregatibacter actinomycetemcomitans (A. act.), triggers expression of the quorum sensing (QS) regulon of Streptococcus mutans, a well-studied model organism for cariogenic streptococci, in dual-species biofilms grown on artificial saliva. The gene for the synthesis of the QS signal XIP is essential for this interaction. Transcriptome sequencing of biofilms revealed that S. mutans up-regulated the complete QS regulon (transformasome and mutacins) in the presence of A. act. and down-regulated oxidative stress related genes. A.act. required the presence of S. mutans for growth. Fimbriae and toxins were its most highly expressed genes and up-regulation of anaerobic metabolism, chaperones and iron acquisition genes was observed in co-culture. Metatranscriptomes from periodontal pockets showed highly variable levels of S. mutans and low levels of A. act.. Transcripts of the alternative sigma-factor SigX, the key regulator of QS in S. mutans, were significantly enriched in periodontal pockets compared to single cultures (log2 4.159, FDR ≤0.001, and expression of mutacin related genes and transformasome components could be detected. CONCLUSION The data show that the complete QS regulon of S. mutans can be induced by an unrelated oral pathogen and S. mutans may be competent in oral biofilms in vivo.
Collapse
Affiliation(s)
- Szymon P Szafrański
- Microbial Communication, Helmholtz-Center for Infection Research, Braunschweig, Germany.,Present address: Hannover Medical School (MHH), Hannover, Germany
| | - Zhi-Luo Deng
- Microbial Communication, Helmholtz-Center for Infection Research, Braunschweig, Germany
| | - Jürgen Tomasch
- Microbial Communication, Helmholtz-Center for Infection Research, Braunschweig, Germany
| | - Michael Jarek
- Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sabin Bhuju
- Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Helena Sztajer
- Microbial Communication, Helmholtz-Center for Infection Research, Braunschweig, Germany
| | - Irene Wagner-Döbler
- Microbial Communication, Helmholtz-Center for Infection Research, Braunschweig, Germany.
| |
Collapse
|
98
|
Sharma K, Mudgil P, Whitehall JS, Gosbell I. Aggregatibacter actinomycetemcomitans osteomyelitis in a 12 year old boy: case report emphasizing the importance of tissue culture, and review of literature. Ann Clin Microbiol Antimicrob 2017; 16:12. [PMID: 28288638 PMCID: PMC5348864 DOI: 10.1186/s12941-017-0186-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 03/06/2017] [Indexed: 12/30/2022] Open
Abstract
Background Aggregatibacter actinomycetemcomitans most commonly causes periodontitis but has been reported to infect heart valves, soft tissue, brain and lungs, and distal bones. Osteomyelitis distal to the jaw is rarely described. Case presentation We report an unusual and rare case of chronic osteomyelitis caused by A. actinomycetemcomitans in the toe of a paediatric patient, and review the available literature. The infection was managed with intravenous antibiotics followed by oral antibiotics. Conclusion This is an unusual presentation of A. actinomycetemcomitans causing chronic osteomyelitis presumed due to nidation in a minimally damaged bone, associated with bacteraemia of an oral commensal. It occurred in the toe, without obvious dental predisposition; associated with minimal clinical disturbance and with muted immune response.
Collapse
Affiliation(s)
- Ketaki Sharma
- Department of Paediatrics, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Poonam Mudgil
- Department of Paediatrics, School of Medicine, Western Sydney University, Sydney, NSW, Australia.
| | - John S Whitehall
- Department of Paediatrics, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| | - Iain Gosbell
- Department of Infectious Diseases and Microbiology, School of Medicine, Western Sydney University, Sydney, NSW, Australia
| |
Collapse
|
99
|
Mira A, Simon-Soro A, Curtis MA. Role of microbial communities in the pathogenesis of periodontal diseases and caries. J Clin Periodontol 2017; 44 Suppl 18:S23-S38. [DOI: 10.1111/jcpe.12671] [Citation(s) in RCA: 128] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Alex Mira
- Department of Health and Genomics; Center for Advanced Research in Public Health; FISABIO Foundation; Valencia Spain
| | - A. Simon-Soro
- Department of Health and Genomics; Center for Advanced Research in Public Health; FISABIO Foundation; Valencia Spain
| | - M. A. Curtis
- Institute of Dentistry; Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London UK
| |
Collapse
|
100
|
Hendrickson EL, Beck DAC, Miller DP, Wang Q, Whiteley M, Lamont RJ, Hackett M. Insights into Dynamic Polymicrobial Synergy Revealed by Time-Coursed RNA-Seq. Front Microbiol 2017; 8:261. [PMID: 28293219 PMCID: PMC5329018 DOI: 10.3389/fmicb.2017.00261] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 02/07/2017] [Indexed: 01/31/2023] Open
Abstract
Many bacterial infections involve polymicrobial communities in which constituent organisms are synergistically pathogenic. Periodontitis, a commonly occurring chronic inflammatory disorder, is induced by multispecies bacterial communities. The periodontal keystone pathogen Porphyromonas gingivalis and the accessory pathogen Streptococcus gordonii exhibit polymicrobial synergy in animal models of disease. Mechanisms of co-adhesion and community formation by P. gingivalis and S. gordonii are well-established; however, little is known regarding the basis for increased pathogenicity. In this study we used time-coursed RNA-Seq to comprehensively and quantitatively examine the dynamic transcriptional landscape of P. gingivalis in a model consortium with S. gordonii. Genes encoding a number of potential virulence determinants had higher relative mRNA levels in the context of dual species model communities than P. gingivalis alone, including adhesins, the Type IX secretion apparatus, and tetratricopeptide repeat (TPR) motif proteins. In contrast, genes encoding conjugation systems and many of the stress responses showed lower levels of expression in P. gingivalis. A notable exception to reduced abundance of stress response transcripts was the genes encoding components of the oxidative stress-related OxyR regulon, indicating an adaptation of P. gingivalis to detoxify peroxide produced by the streptococcus. Collectively, the results are consistent with evolutionary adaptation of P. gingivalis to a polymicrobial oral environment, one outcome of which is increased pathogenic potential.
Collapse
Affiliation(s)
- Erik L Hendrickson
- Center for Microbial Proteomics and Chemical Engineering, University of Washington Seattle, WA, USA
| | - David A C Beck
- Center for Microbial Proteomics and Chemical Engineering, University of WashingtonSeattle, WA, USA; eScience Institute, University of WashingtonSeattle, WA, USA
| | - Daniel P Miller
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry Louisville, KY, USA
| | - Qian Wang
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry Louisville, KY, USA
| | - Marvin Whiteley
- Department of Molecular Biosciences, University of Texas at Austin Austin, TX, USA
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry Louisville, KY, USA
| | - Murray Hackett
- Center for Microbial Proteomics and Chemical Engineering, University of Washington Seattle, WA, USA
| |
Collapse
|