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Rajasekaran JJ, Krishnamurthy HK, Bosco J, Jayaraman V, Krishna K, Wang T, Bei K. Oral Microbiome: A Review of Its Impact on Oral and Systemic Health. Microorganisms 2024; 12:1797. [PMID: 39338471 PMCID: PMC11434369 DOI: 10.3390/microorganisms12091797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2024] [Revised: 08/07/2024] [Accepted: 08/16/2024] [Indexed: 09/30/2024] Open
Abstract
PURPOSE OF REVIEW This review investigates the oral microbiome's composition, functions, influencing factors, connections to oral and systemic diseases, and personalized oral care strategies. RECENT FINDINGS The oral microbiome is a complex ecosystem consisting of bacteria, fungi, archaea, and viruses that contribute to oral health. Various factors, such as diet, smoking, alcohol consumption, lifestyle choices, and medical conditions, can affect the balance of the oral microbiome and lead to dysbiosis, which can result in oral health issues like dental caries, gingivitis, periodontitis, oral candidiasis, and halitosis. Importantly, our review explores novel associations between the oral microbiome and systemic diseases including gastrointestinal, cardiovascular, endocrinal, and neurological conditions, autoimmune diseases, and cancer. We comprehensively review the efficacy of interventions like dental probiotics, xylitol, oral rinses, fluoride, essential oils, oil pulling, and peptides in promoting oral health by modulating the oral microbiome. SUMMARY This review emphasizes the critical functions of the oral microbiota in dental and overall health, providing insights into the effects of microbial imbalances on various diseases. It underlines the significant connection between the oral microbiota and general health. Furthermore, it explores the advantages of probiotics and other dental care ingredients in promoting oral health and addressing common oral issues, offering a comprehensive strategy for personalized oral care.
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Affiliation(s)
- John J. Rajasekaran
- Vibrant Sciences LLC, Santa Clara, CA 95054, USA; (H.K.K.); (V.J.); (K.K.); (T.W.); (K.B.)
| | | | - Jophi Bosco
- Vibrant America LLC, Santa Clara, CA 95054, USA;
| | - Vasanth Jayaraman
- Vibrant Sciences LLC, Santa Clara, CA 95054, USA; (H.K.K.); (V.J.); (K.K.); (T.W.); (K.B.)
| | - Karthik Krishna
- Vibrant Sciences LLC, Santa Clara, CA 95054, USA; (H.K.K.); (V.J.); (K.K.); (T.W.); (K.B.)
| | - Tianhao Wang
- Vibrant Sciences LLC, Santa Clara, CA 95054, USA; (H.K.K.); (V.J.); (K.K.); (T.W.); (K.B.)
| | - Kang Bei
- Vibrant Sciences LLC, Santa Clara, CA 95054, USA; (H.K.K.); (V.J.); (K.K.); (T.W.); (K.B.)
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Pham C, Guo S, Han X, Coleman L, Sze CW, Wang H, Liu J, Li C. A pleiotropic role of sialidase in the pathogenicity of Porphyromonas gingivalis. Infect Immun 2024; 92:e0034423. [PMID: 38376159 PMCID: PMC10929438 DOI: 10.1128/iai.00344-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 02/01/2024] [Indexed: 02/21/2024] Open
Abstract
As one of the keystone pathogens of periodontitis, the oral bacterium Porphyromonas gingivalis produces an array of virulence factors, including a recently identified sialidase (PG0352). Our previous report involving loss-of-function studies indicated that PG0352 plays an important role in the pathophysiology of P. gingivalis. However, this report had not been corroborated by gain-of-function studies or substantiated in different P. gingivalis strains. To fill these gaps, herein we first confirm the role of PG0352 in cell surface structures (e.g., capsule) and serum resistance using P. gingivalis W83 strain through genetic complementation and then recapitulate these studies using P. gingivalis ATCC33277 strain. We further investigate the role of PG0352 and its counterpart (PGN1608) in ATCC33277 in cell growth, biofilm formation, neutrophil killing, cell invasion, and P. gingivalis-induced inflammation. Our results indicate that PG0352 and PGN1608 are implicated in P. gingivalis cell surface structures, hydrophobicity, biofilm formation, resistance to complement and neutrophil killing, and host immune responses. Possible molecular mechanisms involved are also discussed. In summary, this report underscores the importance of sialidases in the pathophysiology of P. gingivalis and opens an avenue to elucidate their underlying molecular mechanisms.
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Affiliation(s)
- Christopher Pham
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Shuaiqi Guo
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Xiao Han
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Laurynn Coleman
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Ching Wooen Sze
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Huizhi Wang
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jun Liu
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, USA
| | - Chunhao Li
- Department of Oral Craniofacial Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, USA
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, USA
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Crowley C, Selvaraj A, Hariharan A, Healy CM, Moran GP. Fusobacterium nucleatum subsp. polymorphum recovered from malignant and potentially malignant oral disease exhibit heterogeneity in adhesion phenotypes and adhesin gene copy number, shaped by inter-subspecies horizontal gene transfer and recombination-derived mosaicism. Microb Genom 2024; 10:001217. [PMID: 38529905 PMCID: PMC10995627 DOI: 10.1099/mgen.0.001217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 02/29/2024] [Indexed: 03/27/2024] Open
Abstract
Fusobacterium nucleatum is an anaerobic commensal of the oral cavity associated with periodontitis and extra-oral diseases, including colorectal cancer. Previous studies have shown an increased relative abundance of this bacterium associated with oral dysplasia or within oral tumours. Using direct culture, we found that 75 % of Fusobacterium species isolated from malignant or potentially malignant oral mucosa were F. nucleatum subsp. polymorphum. Whole genome sequencing and pangenome analysis with Panaroo was carried out on 76 F. nucleatum subsp. polymorphum genomes. F. nucleatum subsp. polymorphum was shown to possesses a relatively small core genome of 1604 genes in a pangenome of 7363 genes. Phylogenetic analysis based on the core genome shows the isolates can be separated into three main clades with no obvious genotypic associations with disease. Isolates recovered from healthy and diseased sites in the same patient are generally highly related. A large repertoire of adhesins belonging to the type V secretion system (TVSS) could be identified with major variation in repertoire and copy number between strains. Analysis of intergenic recombination using fastGEAR showed that adhesin complement is shaped by horizontal gene transfer and recombination. Recombination events at TVSS adhesin genes were not only common between lineages of subspecies polymorphum, but also between different subspecies of F. nucleatum. Strains of subspecies polymorphum with low copy numbers of TVSS adhesin encoding genes tended to have the weakest adhesion to oral keratinocytes. This study highlights the genetic heterogeneity of F. nucleatum subsp. polymorphum and provides a new framework for defining virulence in this organism.
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Affiliation(s)
- Claire Crowley
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Ajith Selvaraj
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Arvind Hariharan
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Claire M. Healy
- Division of Oral and Maxillofacial Surgery, Oral Medicine and Oral Pathology, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
| | - Gary P. Moran
- Division of Oral Biosciences, Dublin Dental University Hospital and School of Dental Science, Trinity College Dublin, Dublin, Ireland
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Lamont RJ, Miller DP, Bagaitkar J. Illuminating the oral microbiome: cellular microbiology. FEMS Microbiol Rev 2023; 47:fuad045. [PMID: 37533213 PMCID: PMC10657920 DOI: 10.1093/femsre/fuad045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 07/11/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023] Open
Abstract
Epithelial cells line mucosal surfaces such as in the gingival crevice and provide a barrier to the ingress of colonizing microorganisms. However, epithelial cells are more than a passive barrier to microbial intrusion, and rather constitute an interactive interface with colonizing organisms which senses the composition of the microbiome and communicates this information to the underlying cells of the innate immune system. Microorganisms, for their part, have devised means to manipulate host cell signal transduction pathways to favor their colonization and survival. Study of this field, which has become known as cellular microbiology, has revealed much about epithelial cell physiology, bacterial colonization and pathogenic strategies, and innate host responses.
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Affiliation(s)
- Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, KY, KY40202, United States
| | - Daniel P Miller
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, VA23298, United States
| | - Juhi Bagaitkar
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, OH43205, United States
- Department of Pediatrics, The Ohio State College of Medicine, Columbus, OH, OH43210, United States
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Gains AF, Lambert DW, Stafford GP. Identification of a Czc-like operon of the periodontal pathobiont P. gingivalis involved in metal ion efflux. Anaerobe 2023; 80:102696. [PMID: 36642290 DOI: 10.1016/j.anaerobe.2023.102696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
OBJECTIVE The study aimed to investigate the role of the PGN2012 gene of the periodontitis contributing pathobiont Porphyromonas gingivalis. PGN2012 is a homolgue of TolC and is a gene our group previously showed was overexpressed in hyperinvasive cells. METHODS The study used a combination of bioinformatics, knockout mutagenesis, growth experiments, biofilm assays and human cell invation assays to investigate PGN2012 function. RESULTS Bioinformatics identified that PGN2012 is part of one of four TolC containing gene loci in P. gingivalis that we predicted may encode a metal resistance RND family tripartite pump, similar to those present in other Gram-negative bacteria, but which are not well understood in anaerobic bacteria. A ΔPGN2012 deletion displayed slightly reduced growth in liquid culture but did not effect biofilm formation or human cell invasion. When metal ions were included in the medium the mutant displayed significantly increased sensitivity to the divalent metal ions Zn2+ (500 μM), Co2+ (2 mM), and Cd2+(0.1 mM) but not Cu2+. CONCLUSIONS We propose to rename the PGN2012-2014 genes czcCBA, which we suggest plays a role in intracellular stress resistance where zinc is often employed by host cells in antibacterial defence with implications for chronic infection in humans.
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Affiliation(s)
- A F Gains
- School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - D W Lambert
- School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK
| | - G P Stafford
- School of Clinical Dentistry, University of Sheffield, Sheffield, S10 2TA, UK.
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Li Z, Chen G, Wang P, Sun M, Zhao J, Li A, Sun Q. Alterations of the Oral Microbiota Profiles in Chinese Patient With Oral Cancer. Front Cell Infect Microbiol 2021; 11:780067. [PMID: 34956932 PMCID: PMC8696029 DOI: 10.3389/fcimb.2021.780067] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/08/2021] [Indexed: 01/14/2023] Open
Abstract
Oral cancer is the most common malignant tumor in the oral and maxillofacial region, of which more than 90% is squamous cell carcinoma. The incidence of oral cancer is on the rise worldwide. An imbalance between the microorganism composition and its host may lead to the occurrence of oral malignant tumors. Accumulating evidence suggests that the oral microbiota plays an important role in oral cancer; however, the association between oral microbiota and oral cancer has not yet been comprehensively studied. In this study, metagenomic sequencing was used to compare the microbial composition of three groups of samples from Chinese patients with oral cancer, patients with precancerous lesion, and normal individuals. In terms of microbiota richness, the oral microbiota of patients with precancerous lesions was richer than that of oral cancer patients and healthy controls, whereas in terms of microbiota diversity, there was little difference between the three groups. The three groups of samples exhibited statistically significant differences in microbiota composition and metabolic function at the family, genus, and species levels (P < 0.05). The differentially enriched phylum in oral cancer samples was Bacteroidetes (P < 0.05). At the genus level, the main differentially enriched taxa were Prevotella, Peptostreptococcus, Carnobacterium, and Diastella (P < 0.05). The species level was differentially enriched in Prevotella intermedia and Peptostreptococcus stomatis (p < 0.05). The prediction of microbiota function shows that oral cancer is mainly associated with coenzyme A biosynthesis, phosphopantothenic acid biosynthesis, inosine 5’-phosphate degradation, and riboflavin biosynthesis. Furthermore, the increase in C-reactive protein level in oral cancer patients was found to be closely related to P. intermedia. Overall, oral bacterial profiles showed significant differences between the oral cancer group and normal group. Hence, microbes can be employed as diagnostic markers and treatment targets for oral cancer.
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Affiliation(s)
- Zixuan Li
- Department of Oral and Maxillofacial Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Gang Chen
- Shenzhen Stomatology Hospital (Pingshan), Southern Medical University, Shenzhen, China
| | - Panpan Wang
- Department of Oral and Maxillofacial Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Minglei Sun
- Department of Oral and Maxillofacial Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Junfang Zhao
- Department of Oral and Maxillofacial Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Ang Li
- Health Management Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Qiang Sun
- Department of Oral and Maxillofacial Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Frey AM, Satur MJ, Phansopa C, Honma K, Urbanowicz PA, Spencer DIR, Pratten J, Bradshaw D, Sharma A, Stafford G. Characterization of Porphyromonas gingivalis sialidase and disruption of its role in host-pathogen interactions. MICROBIOLOGY-SGM 2020; 165:1181-1197. [PMID: 31517596 DOI: 10.1099/mic.0.000851] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Key to onset and progression of periodontitis is a complex relationship between oral bacteria and the host. The organisms most associated with severe periodontitis are the periodontal pathogens of the red complex: Tannerella forsythia, Treponema denticola and Porphyromonas gingivalis. These organisms express sialidases, which cleave sialic acid from host glycoproteins, and contribute to disease through various mechanisms. Here, we expressed and purified recombinant P. gingivalis sialidase SiaPG (PG_0352) and characterized its activity on a number of substrates, including host sialoglycoproteins and highlighting the inability to cleave diacetylated sialic acids - a phenomenon overcome by the NanS sialate-esterase from T. forsythia. Indeed SiaPG required NanS to maximize sialic acid harvesting from heavily O-acetylated substrates such as bovine salivary mucin, hinting at the possibility of interspecies cooperation in sialic acid release from host sources by these members of the oral microbiota. Activity of SiaPG and P. gingivalis was inhibited using the commercially available chemotherapeutic zanamivir, indicating its potential as a virulence inhibitor, which also inhibited sialic acid release from mucin, and was capable of inhibiting biofilm formation of P. gingivalis on oral glycoprotein sources. Zanamivir also inhibited attachment and invasion of oral epithelial cells by P. gingivalis and other periodontal pathogens, both in monospecies but also in multispecies infection experiments, indicating potential to suppress host-pathogen interactions of a mixed microbial community. This study broadens our understanding of the multifarious roles of bacterial sialidases in virulence, and indicates that their inhibition with chemotherapeutics could be a promising strategy for periodontitis therapy.
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Affiliation(s)
- Andrew M Frey
- University of South Florida, Department of Cell Biology, Microbiology, and Molecular Biology, 4202 East Fowler Ave, ISA2015, Tampa, FL 33620, USA.,Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
| | - Marianne J Satur
- Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
| | - Chatchawal Phansopa
- Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
| | - Kiyonobu Honma
- Department of Oral Biology, University at Buffalo, Buffalo, NY, USA
| | | | | | - Jonathan Pratten
- Oral Health R&D, GlaxoSmithKline, St. Georges Avenue, Weybridge, KT13 0DE, UK
| | - David Bradshaw
- Oral Health R&D, GlaxoSmithKline, St. Georges Avenue, Weybridge, KT13 0DE, UK
| | - Ashu Sharma
- Department of Oral Biology, University at Buffalo, Buffalo, NY, USA
| | - Graham Stafford
- Integrated BioSciences, School of Clinical Dentistry, The University of Sheffield, 19 Claremont Crescent, Sheffield S10 2TA, UK
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Lu M, Xuan S, Wang Z. Oral microbiota: A new view of body health. FOOD SCIENCE AND HUMAN WELLNESS 2019. [DOI: 10.1016/j.fshw.2018.12.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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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.
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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.
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Al-Taweel FBH, Al-Magsoosi MJN, Douglas CWI, Whawell SA. Identification of key determinants in Porphyromonas gingivalis host-cell invasion assays. Eur J Oral Sci 2018; 126:367-372. [PMID: 30070725 DOI: 10.1111/eos.12557] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2018] [Indexed: 01/09/2023]
Abstract
The periodontal pathogen Porphyromonas gingivalis can invade host cells, a virulence trait which may contribute to the persistence of infection at subgingival sites. Whilst the antibiotic protection assay has been commonly employed to investigate and quantify P. gingivalis invasion, data obtained have varied widely and a thorough investigation of the factors influencing this is lacking. We investigated the role of a number of bacterial and host-cell factors and report that the growth phase of P. gingivalis, source (laboratory strain vs. clinical strain), host-cell identity (cell line vs. primary), host-cell lysis method, and host-cell passage number had no significant effect on bacterial invasion. However, incubation time, host-cell seeding density, method of quantification (viable count vs. DNA), and whether host cells were plated or in suspension, were shown to influence invasion. Also, cells isolated by rapid adhesion to fibronectin exhibited higher levels of P. gingivalis invasion, possibly as a result of increased levels of active α5β1 integrin. Interestingly, this may represent a population of cells with stem cell-like properties. This study provides important new information by identifying the most important factors that influence P. gingivalis invasion assays and may help to explain variations in the levels previously reported.
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Affiliation(s)
- Firas B H Al-Taweel
- Department of Periodontics, College of Dentistry, University of Baghdad, Baghdad, Iraq
| | | | - Charles W I Douglas
- Academic Unit of Oral & Maxillofacial Medicine, Surgery & Pathology, School of Clinical Dentistry, University of Sheffield, Sheffield, UK
| | - Simon A Whawell
- Academic Unit of Oral & Maxillofacial Medicine, Surgery & Pathology, School of Clinical Dentistry, University of Sheffield, Sheffield, UK
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11
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Evidence for a carbohydrate-binding module (CBM) of Tannerella forsythia NanH sialidase, key to interactions at the host–pathogen interface. Biochem J 2018; 475:1159-1176. [DOI: 10.1042/bcj20170592] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 02/20/2018] [Accepted: 02/26/2018] [Indexed: 12/15/2022]
Abstract
Bacterial sialidases cleave terminal sialic acid from a variety of host glycoproteins, and contribute to survival and growth of many human-dwelling bacterial species, including various pathogens. Tannerella forsythia, an oral, Gram-negative, fastidious anaerobe, is a key organism in periodontal disease and possesses a dedicated sialic acid utilisation and scavenging (nan) operon, including NanH sialidase. Here, we describe biochemical characterisation of recombinant NanH, including its action on host-relevant sialoglycans such as sialyl Lewis A and sialyl Lewis X (SLeA/X), and on human cell-attached sialic acids directly, uncovering that it is a highly active broad specificity sialidase. Furthermore, the N-terminal domain of NanH was hypothesised and proved to be capable of binding to a range of sialoglycans and non-sialylated derivatives with Kd in the micromolar range, as determined by steady-state tryptophan fluorescence spectroscopy, but it has no catalytic activity in isolation from the active site. We consider this domain to represent the founding member of a novel subfamily of carbohydrate-binding module (CBM), involved in glycosidase-ligand binding. In addition, we created a catalytically inactive version of the NanH enzyme (FRIP → YMAP) that retained its ability to bind sialic acid-containing ligands and revealed for the first time that binding activity of a CBM is enhanced by association with the catalytic domain. Finally, we investigated the importance of Lewis-type sialoglycans on T. forsythia–host interactions, showing that nanomolar amounts of SLeA/X were capable of reducing invasion of oral epithelial cells by T. forsythia, suggesting that these are key ligands for bacterial–cellular interactions during periodontal disease.
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12
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Ho MH, Lamont RJ, Xie H. A novel peptidic inhibitor derived from Streptococcus cristatus ArcA attenuates virulence potential of Porphyromonas gingivalis. Sci Rep 2017; 7:16217. [PMID: 29176569 PMCID: PMC5701168 DOI: 10.1038/s41598-017-16522-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 11/13/2017] [Indexed: 12/11/2022] Open
Abstract
Periodontitis is a global health problem and the 6th most common infectious disease worldwide. Porphyromonas gingivalis is considered a keystone pathogen in the disease and is capable of elevating the virulence potential of the periodontal microbial community. Strategies that interfere with P. gingivalis colonization and expression of virulence factor are therefore attractive approaches for preventing and treating periodontitis. We have previously reported that an 11-mer peptide (SAPP) derived from Streptococcus cristatus arginine deiminase (ArcA) was able to repress the expression and production of several well-known P. gingivalis virulence factors including fimbrial proteins and gingipains. Herein we expand and develop these studies to ascertain the impact of this peptide on phenotypic properties of P. gingivalis related to virulence potential. We found that growth rate was not altered by exposure of P. gingivalis to SAPP, while monospecies and heterotypic biofilm formation, and invasion of oral epithelial cells were inhibited. Additionally, SAPP was able to impinge the ability of P. gingivalis to dysregulate innate immunity by repressing gingipain-associated degradation of interleukin-8 (IL8). Hence, SAPP has characteristics that could be exploited for the manipulation of P. gingivalis levels in oral communities and preventing realization of virulence potential.
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Affiliation(s)
- Meng-Hsuan Ho
- Department of Oral Biology, Meharry Medical College, Nashville, TN, 37208, USA
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, KY, 40202, USA
| | - Hua Xie
- Department of Oral Biology, Meharry Medical College, Nashville, TN, 37208, USA.
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13
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Jung YJ, Jun HK, Choi BK. Porphyromonas gingivalis suppresses invasion of Fusobacterium nucleatum into gingival epithelial cells. J Oral Microbiol 2017; 9:1320193. [PMID: 28748028 PMCID: PMC5508355 DOI: 10.1080/20002297.2017.1320193] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/01/2017] [Accepted: 04/13/2017] [Indexed: 01/12/2023] Open
Abstract
Invasion of periodontal pathogens into periodontal tissues is an important step that can cause tissue destruction in periodontal diseases. Porphyromonas gingivalis is a keystone pathogen and its gingipains are key virulence factors. Fusobacterium nucleatum is a bridge organism that mediates coadhesion of disease-causing late colonizers such as P. gingivalis and early colonizers during the development of dental biofilms. The aim of this study was to investigate how P. gingivalis, in particular its gingipains, influences the invasion of coinfecting F. nucleatum into gingival epithelial cells. When invasion of F. nucleatum was analyzed after 4 h of infection, invasion of F. nucleatum was suppressed in the presence of P. gingivalis compared with during monoinfection. However, coinfection with a gingipain-null mutant of P. gingivalis did not affect invasion of F. nucleatum. Inhibition of PI3K reduced invasion of F. nucleatum. P. gingivalis inactivated the PI3K/AKT pathway, which was also dependent on gingipains. Survival of intracellular F. nucleatum was promoted by P. gingivalis with Arg gingipain mutation. The results suggest that P. gingivalis, in particular its gingipains, can affect the invasion of coinfecting F. nucleatum through modulating intracellular signaling of the host cells.
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Affiliation(s)
- Young-Jung Jung
- Department of Oral Microbiology and Immunology, School of Dentistry, University of Louisville, KY, USA
| | - Hye-Kyoung Jun
- Department of Oral Microbiology and Immunology, School of Dentistry, University of Louisville, KY, USA
| | - Bong-Kyu Choi
- Department of Oral Microbiology and Immunology, School of Dentistry, University of Louisville, KY, USA.,Dental Research Institute;Seoul National University, Seoul, Republic of Korea
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14
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Naylor KL, Widziolek M, Hunt S, Conolly M, Hicks M, Stafford P, Potempa J, Murdoch C, Douglas CWI, Stafford GP. Role of OmpA2 surface regions of Porphyromonas gingivalis in host-pathogen interactions with oral epithelial cells. Microbiologyopen 2016; 6. [PMID: 27595778 PMCID: PMC5300881 DOI: 10.1002/mbo3.401] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/03/2016] [Accepted: 08/08/2016] [Indexed: 01/27/2023] Open
Abstract
Outer membrane protein A (OmpA) is a key outer membrane protein found in Gram‐negative bacteria that contributes to several crucial processes in bacterial virulence. In Porphyromonas gingivalis, OmpA is predicted as a heterotrimer of OmpA1 and OmpA2 subunits encoded by adjacent genes. Here we describe the role of OmpA and its individual subunits in the interaction of P. gingivalis with oral cells. Using knockout mutagenesis, we show that OmpA2 plays a significant role in biofilm formation and interaction with human epithelial cells. We used protein structure prediction software to identify extracellular loops of OmpA2, and determined these are involved in interactions with epithelial cells as evidenced by inhibition of adherence and invasion of P. gingivalis by synthetic extracellular loop peptides and the ability of the peptides to mediate interaction of latex beads with human cells. In particular, we observe that OmpA2‐loop 4 plays an important role in the interaction with host cells. These data demonstrate for the first time the important role of P. gingivalis OmpA2 extracellular loops in interaction with epithelial cells, which may help design novel peptide‐based antimicrobial therapies for periodontal disease.
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Affiliation(s)
- Kathryn L Naylor
- School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
| | - Magdalena Widziolek
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Stuart Hunt
- School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
| | - Mary Conolly
- School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
| | - Matthew Hicks
- School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
| | - Prachi Stafford
- Biomolecular Research Centre, Sheffield Hallam University, City Campus, Sheffield, United Kingdom
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.,Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, Kentucky
| | - Craig Murdoch
- School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
| | - C W Ian Douglas
- School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
| | - Graham P Stafford
- School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
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15
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Connolly E, Millhouse E, Doyle R, Culshaw S, Ramage G, Moran GP. The Porphyromonas gingivalis hemagglutinins HagB and HagC are major mediators of adhesion and biofilm formation. Mol Oral Microbiol 2016; 32:35-47. [PMID: 28051836 DOI: 10.1111/omi.12151] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2015] [Indexed: 11/28/2022]
Abstract
Porphyromonas gingivalis is a bacterium associated with chronic periodontitis that possesses a family of genes encoding hemagglutinins required for heme acquisition. In this study we generated ΔhagB and ΔhagC mutants in strain W83 and demonstrate that both hagB and hagC are required for adherence to oral epithelial cells. Unexpectedly, a double ΔhagB/ΔhagC mutant had less severe adherence defects than either of the single mutants, but was found to exhibit increased expression of the gingipain-encoding genes rgpA and kgp, suggesting that a ΔhagB/ΔhagC mutant is only viable in populations of cells that exhibit increased expression of genes involved in heme acquisition. Disruption of hagB in the fimbriated strain ATCC33277 demonstrated that HagB is also required for stable attachment of fimbriated bacteria to oral epithelial cells. Mutants of hagC were also found to form defective single and multi-species biofilms that had reduced biomass relative to biofilms formed by the wild-type strain. This study highlights the hitherto unappreciated importance of these genes in oral colonization and biofilm formation.
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Affiliation(s)
- E Connolly
- Division of Oral Biosciences, Dublin Dental University Hospital, School of Dental Science, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - E Millhouse
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, School of Dental Science, University of Glasgow, Glasgow, UK
| | - R Doyle
- Division of Oral Biosciences, Dublin Dental University Hospital, School of Dental Science, Trinity College Dublin, University of Dublin, Dublin, Ireland
| | - S Culshaw
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, School of Dental Science, University of Glasgow, Glasgow, UK
| | - G Ramage
- Infection and Immunity Research Group, Glasgow Dental School, School of Medicine, College of Medical, Veterinary and Life Sciences, School of Dental Science, University of Glasgow, Glasgow, UK
| | - G P Moran
- Division of Oral Biosciences, Dublin Dental University Hospital, School of Dental Science, Trinity College Dublin, University of Dublin, Dublin, Ireland
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16
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Hosn KN, Jefferson MM, Leding C, Shokouh‐Amiri S, Thomas EL. Inhibitors of bacterial protease enzymes for periodontal therapy. Clin Exp Dent Res 2015; 1:18-25. [PMID: 29744136 PMCID: PMC5839262 DOI: 10.1002/cre2.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/24/2015] [Accepted: 08/04/2015] [Indexed: 11/10/2022] Open
Abstract
Locally applied therapeutic agents have become established in the treatment of periodontal disease. Inhibition of human metalloproteases by metal-chelating antibiotics contributes to the utility of local therapy. Adding inhibitors of bacterial proteases might extend and improve local therapy. The periodontal pathogen Porphyromonas gingivalis (Pg) produces two extracellular cysteine proteases (gingipains Rgp and Kgp) that are virulence factors and contribute to destruction of oral tissues. Our aims were to compare efficacy of protease inhibitors against gingipains and evaluate bactericidal activity of the inhibitors. Protease activity was measured in fluorescent assays with specific Rgp and Kgp substrates. Bacterial viability was measured with BacLight™ (Invitrogen, Inc., Carlsbad, CA) reagents. Pairs of inhibitors of Rgp and Kgp, respectively, were leupeptin and cathepsin B inhibitor II, KYT-1 and KYT-36, and PPACK and Z-FK-ck. The cysteine-protease inhibitor E64 was also tested. Rgp activity was higher than Kgp activity, and activity was higher in Pg 33277 and 49417 cell suspensions than in media. Concentrations required for 50% inhibition of Rgp in cell suspensions were 2 × 10-9, 2 × 10-9, 2 × 10-8, and 5 × 10-5 M for KYT-1, PPACK, leupeptin, and E64, respectively. Concentrations required for 50% Kgp inhibition were 5 × 10-10, 1 × 10-9, and 5 × 10-8 M for Z-FK-ck, KYT-36, and cathepsin B inhibitor II. E64 did not inhibit Kgp. Inhibition of Rgp could be accounted for by competition for binding between the arginine residue of the substrate and the guanidinobutane portion of E64. PPACK was the least selective, with a 10-fold difference in concentrations that inhibited Rgp and Kgp. KYT-1 and Z-FK-ck inhibited both Rgp and Kgp, but inhibitory concentrations differed by 10,000-fold. At up to 1 × 10-4 M, only Z-FK-ck was bactericidal. KYT-1 and KYT-36 were remarkably effective even when used in cell suspensions in which bacterial proteins could bind inhibitors or compete for binding to gingipains. These inhibitors might prove useful as an addition to locally applied therapeutic agents.
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Affiliation(s)
- Kalid N. Hosn
- Periodontology DepartmentUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Mary Margaret Jefferson
- Bioscience Research Department, College of DentistryUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Carlton Leding
- Bioscience Research Department, College of DentistryUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Solomon Shokouh‐Amiri
- Bioscience Research Department, College of DentistryUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
| | - Edwin L. Thomas
- Bioscience Research Department, College of DentistryUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
- Microbiology, Immunology & Biochemistry DepartmentUniversity of Tennessee Health Science CenterMemphisTennesseeUSA
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17
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Olsen I, Progulske-Fox A. Invasion of Porphyromonas gingivalis strains into vascular cells and tissue. J Oral Microbiol 2015; 7:28788. [PMID: 26329158 PMCID: PMC4557090 DOI: 10.3402/jom.v7.28788] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 01/06/2023] Open
Abstract
Porphyromonas gingivalis is considered a major pathogen in adult periodontitis and is also associated with multiple systemic diseases, for example, cardiovascular diseases. One of its most important virulence factors is invasion of host cells. The invasion process includes attachment, entry/internalization, trafficking, persistence, and exit. The present review discusses these processes related to P. gingivalis in cardiovascular cells and tissue. Although most P. gingivalis strains invade, the invasion capacity of strains and the mechanisms of invasion including intracellular trafficking among them differ. This is consistent with the fact that there are significant differences in the pathogenicity of P. gingivalis strains. P. gingivalis invasion mechanisms are also dependent on types of host cells. Although much is known about the invasion process of P. gingivalis, we still have little knowledge of its exit mechanisms. Nevertheless, it is intriguing that P. gingivalis can remain viable in human cardiovascular cells and atherosclerotic plaque and later exit and re-enter previously uninfected host cells.
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Affiliation(s)
- Ingar Olsen
- Department of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway;
| | - Ann Progulske-Fox
- Department of Oral Biology and Center for Molecular Microbiology, University of Florida College of Dentistry, Gainesville, FL, USA
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18
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Abstract
Oral colonising bacteria are highly adapted to the various environmental niches harboured within the mouth, whether that means while contributing to one of the major oral diseases of caries, pulp infections, or gingival/periodontal disease or as part of a commensal lifestyle. Key to these infections is the ability to adhere to surfaces via a range of specialised adhesins targeted at both salivary and epithelial proteins, their glycans and to form biofilm. They must also resist the various physical stressors they are subjected to, including pH and oxidative stress. Possibly most strikingly, they have developed the ability to harvest both nutrient sources provided by the diet and those derived from the host, such as protein and surface glycans. We have attempted to review recent developments that have revealed much about the molecular mechanisms at work in shaping the physiology of oral bacteria and how we might use this information to design and implement new treatment strategies.
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19
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Characterisation and optimisation of organotypic oral mucosal models to study Porphyromonas gingivalis invasion. Microbes Infect 2014; 16:310-9. [PMID: 24491281 DOI: 10.1016/j.micinf.2014.01.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 01/15/2014] [Accepted: 01/22/2014] [Indexed: 11/24/2022]
Abstract
Porphyromonas gingivalis is a Gram-negative, keystone pathogen in periodontitis that leads to tissue destruction and ultimately tooth loss. The organism is able to infect oral epithelial cells and two-dimensional (monolayer) cultures have been used to investigate this process. However, recently there has been interest in the use of three-dimensional, organotypic mucosal models to analyse infection. These models are composed of collagen-embedded fibroblasts overlain with multilayers of oral epithelial cells. In this study we report for the first time significant differences in the response of oral mucosal models to P. gingivalis infection when compared to monolayer cultures of oral epithelial cells. Intracellular survival (3-fold) and bacterial release (4-fold) of P. gingivalis was significantly increased in mucosal models compared with monolayer cultures, which may be due to the multi-layered nature and exfoliation of epithelial cells in these organotypic models. Furthermore, marked differences in the cytokine profile between infected organotypic models and monolayer cultures were observed, particularly for CXCL8 and IL6, which suggested that degradation of cytokines by P. gingivalis may be less pronounced in organotypic compared to monolayer cultures. These data suggest that use of oral mucosal models may provide a greater understanding of the host responses to P. gingivalis invasion than simple monolayer cultures.
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20
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Wayakanon K, Thornhill MH, Douglas CWI, Lewis AL, Warren NJ, Pinnock A, Armes SP, Battaglia G, Murdoch C. Polymersome-mediated intracellular delivery of antibiotics to treat Porphyromonas gingivalis-infected oral epithelial cells. FASEB J 2013; 27:4455-65. [PMID: 23921377 DOI: 10.1096/fj.12-225219] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The gram-negative anaerobe Porphyromonas gingivalis colonizes the gingival crevice and is etiologically associated with periodontal disease that can lead to alveolar bone damage and resorption, promoting tooth loss. Although susceptible to antibiotics, P. gingivalis can evade antibiotic killing by residing within gingival keratinocytes. This provides a reservoir of organisms that may recolonize the gingival crevice once antibiotic therapy is complete. Polymersomes are nanosized amphiphilic block copolymer vesicles that can encapsulate drugs. Cells internalize polymersomes by endocytosis into early endosomes, where they are disassembled by the low pH, causing intracellular release of their drug load. In this study, polymersomes were used as vehicles to deliver antibiotics in an attempt to kill intracellular P. gingivalis within monolayers of keratinocytes and organotypic oral mucosal models. Polymersome-encapsulated metronidazole or doxycycline, free metronidazole, or doxycycline, or polymersomes alone as controls, were used, and the number of surviving intracellular P. gingivalis was quantified after host cell lysis. Polymersome-encapsulated metronidazole or doxycycline significantly (P<0.05) reduced the number of intracellular P. gingivalis in both monolayer and organotypic cultures compared to free antibiotic or polymersome alone controls. Polymersomes are effective delivery vehicles for antibiotics that do not normally gain entry to host cells. This approach could be used to treat recurrent periodontitis or other diseases caused by intracellular-dwelling organisms.
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Affiliation(s)
- Kornchanok Wayakanon
- 1C.M., Unit of Oral and Maxillofacial Medicine and Surgery, School of Clinical Dentistry, University of Sheffield, Claremont Crescent, Sheffield, S10 2TA, UK.
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21
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Stafford P, Higham J, Pinnock A, Murdoch C, Douglas CWI, Stafford GP, Lambert DW. Gingipain-dependent degradation of mammalian target of rapamycin pathway proteins by the periodontal pathogen Porphyromonas gingivalis during invasion. Mol Oral Microbiol 2013; 28:366-78. [PMID: 23714361 DOI: 10.1111/omi.12030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/19/2013] [Indexed: 01/09/2023]
Abstract
Porphyromonas gingivalis and Tannerella forsythia are gram-negative pathogens strongly associated with periodontitis. Their abilities to interact, invade and persist within host cells are considered crucial to their pathogenicity, but the mechanisms by which they subvert host defences are not well understood. In this study, we set out to investigate whether P. gingivalis and T. forsythia directly target key signalling molecules that may modulate the host cell phenotype to favour invasion and persistence. Our data identify, for the first time, that P. gingivalis, but not T. forsythia, reduces levels of intracellular mammalian target of rapamycin (mTOR) in oral epithelial cells following invasion over a 4-h time course, via the action of gingipains. The ability of cytochalasin D to abrogate P. gingivalis-mediated mTOR degradation suggests that this effect is dependent upon cellular invasion. We also show that levels of several other proteins in the mTOR signalling pathway are modulated by gingipains, either directly or as a consequence of mTOR degradation including p-4E-BP1. Taken together, our data suggest that P. gingivalis manipulates the mTOR pathway, providing evidence for a potentially novel mechanism by which P. gingivalis mediates its effects on host cell responses to infection.
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Affiliation(s)
- P Stafford
- Integrated Bioscience, School of Clinical Dentistry, University of Sheffield, Sheffield, UK
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22
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Gule NP, de Kwaadsteniet M, Cloete TE, Klumperman B. Furanone-containing poly(vinyl alcohol) nanofibers for cell-adhesion inhibition. WATER RESEARCH 2013; 47:1049-1059. [PMID: 23261340 DOI: 10.1016/j.watres.2012.11.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 11/03/2012] [Accepted: 11/07/2012] [Indexed: 06/01/2023]
Abstract
The 3(2H) furanone derivative 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) was investigated for its antimicrobial and cell-adhesion inhibition properties against Klebsiella pneumoniae Xen 39, Staphylococcus aureus Xen 36, Escherichia coli Xen 14, Pseudomonas aeruginosa Xen 5 and Salmonella typhimurium Xen 26. Nanofibers electrospun from solution blends of DMHF and poly(vinyl alcohol) (PVA) were tested for their ability to inhibit surface-attachment of bacteria. Antimicrobial and adhesion inhibition activity was determined via the plate counting technique. To quantify viable but non-culturable cells and to validate the plate counting results, bioluminescence and fluorescence studies were carried out. Nanofiber production was upscaled using the bubble electrospinning technique. To ascertain that no DMHF leached into filtered water, samples of water filtered through the nanofibrous mats were analyzed using gas chromatography coupled with mass spectrometry (GC-MS). Scanning electron microscopy (SEM) and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) were used to characterize the electrospun nanofibers.
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Affiliation(s)
- Nonjabulo P Gule
- Division of Polymer Science, University of Stellenbosch, Stellenbosch, South Africa
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23
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Gule NP, Bshena O, de Kwaadsteniet M, Cloete TE, Klumperman B. Immobilized Furanone Derivatives as Inhibitors for Adhesion of Bacteria on Modified Poly(styrene-co-maleic anhydride). Biomacromolecules 2012; 13:3138-50. [DOI: 10.1021/bm300932u] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Nonjabulo P. Gule
- Division of Polymer Science, University of Stellenbosch, Stellenbosch, South Africa
| | - Osama Bshena
- Division of Polymer Science, University of Stellenbosch, Stellenbosch, South Africa
| | | | - Thomas E. Cloete
- Department of Microbiology, University of Stellenbosch, Stellenbosch, South Africa
| | - Bert Klumperman
- Division of Polymer Science, University of Stellenbosch, Stellenbosch, South Africa
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24
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Sialidase and sialoglycoproteases can modulate virulence in Porphyromonas gingivalis. Infect Immun 2011; 79:2779-91. [PMID: 21502589 DOI: 10.1128/iai.00106-11] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The Porphyromonas gingivalis recombinant VimA can interact with the gingipains and several other proteins, including a sialidase. Sialylation can be involved in protein maturation; however, its role in virulence regulation in P. gingivalis is unknown. The three sialidase-related proteins in P. gingivalis showed the characteristic sialidase Asp signature motif (SXDXGXTW) and other unique domains. To evaluate the roles of the associated genes, randomly chosen P. gingivalis isogenic mutants created by allelic exchange and designated FLL401 (PG0778::ermF), FLL402 (PG1724::ermF), and FLL403 (PG0352::ermF-ermAM) were characterized. Similar to the wild-type strain, FLL402 and FLL403 displayed a black-pigmented phenotype in contrast to FLL401, which was not black pigmented. Sialidase activity in P. gingivalis FLL401 was reduced by approximately 70% in comparison to those in FLL402 and FLL403, which were reduced by approximately 42% and 5%, respectively. Although there were no changes in the expression of the gingipain genes, their activities were reduced by 60 to 90% in all the isogenic mutants compared to that for the wild type. Immunoreactive bands representing the catalytic domains for RgpA, RgpB, and Kgp were present in FLL402 and FLL403 but were missing in FLL401. While adhesion was decreased, the capacity for invasion of epithelial cells by the isogenic mutants was increased by 11 to 16% over that of the wild-type strain. Isogenic mutants defective in PG0778 and PG0352 were more sensitive to hydrogen peroxide than the wild type. Taken together, these results suggest that the P. gingivalis sialidase activity may be involved in regulating gingipain activity and other virulence factors and may be important in the pathogenesis of this organism.
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