scholarly journals Functional Genomics Approach to Identifying Genes Required for Biofilm Development by Streptococcus mutans

2002 ◽  
Vol 68 (3) ◽  
pp. 1196-1203 ◽  
Author(s):  
Zezhang T. Wen ◽  
Robert A. Burne
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Regulatory Protein ◽  
Amino Acid Residues ◽  
Global Regulators ◽  
Insertional Inactivation ◽  
Bacterial Quorum Sensing ◽  
Bacterial Quorum ◽  
Biofilm Development

ABSTRACT Streptococcus mutans, the primary etiological agent of human dental caries, is an obligate biofilm-forming bacterium. The goals of this study were to identify the gene(s) required for biofilm formation by this organism and to elucidate the role(s) that some of the known global regulators of gene expression play in controlling biofilm formation. In S. mutans UA159, the brpA gene (for biofilm regulatory protein) was found to encode a novel protein of 406 amino acid residues. A strain carrying an insertionally inactivated copy of brpA formed longer chains than did the parental strain, aggregated in liquid culture, and was unable to form biofilms as shown by an in vitro biofilm assay. A putative homologue of the enzyme responsible for synthesis of autoinducer II (AI-2) of the bacterial quorum-sensing system was also identified in S. mutans UA159, but insertional inactivation of the gene (luxS Sm) did not alter colony or cell morphology or diminish the capacity of S. mutans to form biofilms. We also examined the role of the homologue of the Bacillus subtilis catabolite control protein CcpA in S. mutans in biofilm formation, and the results showed that loss of CcpA resulted in about a 60% decrease in the ability to form biofilms on an abiotic surface. From these data, we conclude that CcpA and BrpA may regulate genes that are required for stable biofilm formation by S. mutans.

scholarly journals Role of the Streptococcus mutans irvA Gene in GbpC-Independent, Dextran-Dependent Aggregation and Biofilm Formation

2009 ◽  
Vol 75 (22) ◽  
pp. 7037-7043 ◽  
Author(s):  
Min Zhu ◽  
Dragana Ajdić ◽  
Yuan Liu ◽  
David Lynch ◽  
Justin Merritt ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Growth Conditions ◽  
Parental Background ◽  
A Cell ◽  
Major Surface ◽  
Biofilm Development ◽  
Small Aggregation

ABSTRACT Dextran-dependent aggregation (DDAG) of Streptococcus mutans is an in vitro phenomenon that is believed to represent a property of the organism that is beneficial for sucrose-dependent biofilm development. GbpC, a cell surface glucan-binding protein, is responsible for DDAG in S. mutans when cultured under defined stressful conditions. Recent reports have described a putative transcriptional regulator gene, irvA, located just upstream of gbpC, that is normally repressed by the product of an adjacent gene, irvR. When repression of irvA is relieved, there is a resulting increase in the expression of GbpC and decreases in competence and synthesis of the antibiotic mutacin I. This study examined the role of irvA in DDAG and biofilm formation by engineering strains that overexpressed irvA (IrvA+) on an extrachromosomal plasmid. The IrvA+ strain displayed large aggregation particles that did not require stressful growth conditions. A novel finding was that overexpression of irvA in a gbpC mutant background retained a measure of DDAG, albeit very small aggregation particles. Biofilms formed by the IrvA+ strain in the parental background possessed larger-than-normal microcolonies. In a gbpC mutant background, the overexpression of irvA reversed the fragile biofilm phenotype normally associated with loss of GbpC. Real-time PCR and Northern blot analyses found that expression of gbpC did not change significantly in the IrvA+ strain but expression of spaP, encoding the major surface adhesin P1, increased significantly. Inactivation of spaP eliminated the small-particle DDAG. The results suggest that IrvA promotes DDAG not only by GbpC, but also via an increase in P1.

Streptococcus mutans biofilm inhibition using antisense oligonucleotide to glucosyltransferases B and C

2015 ◽  
Vol 22 (2) ◽  
pp. 85-92
Author(s):  
Povilas Kalesinskas ◽  
Tomas Kačergius ◽  
Arvydas Ambrozaitis ◽  
Ryo Jimbo ◽  
Dan Ericson
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Roughness Parameter ◽  
Preventive Measure ◽  
Modern Society ◽  
Biofilm Inhibition ◽  
Dental Biofilm ◽  
Glass Slides ◽  
Biofilm Development

Background. Biofilm formation by Streptococcus mutans bacteria on teeth leads to dental caries, which still remains one of the most prevalent human diseases strongly related to increase of dietary sucrose consumption in modern society. In the biofilm, sucrose is metabolized by S. mutans to acids causing tooth decay. S. mutans also produces glucosyltransferases (Gtfs) for synthesis of sticky glucan polymers from sucrose that provides matrix for biofilm formation on teeth. For reducing biofilm build-up, one preventive measure could be blocking of Gtf synthesis. The aim of this study was to test antisense phosphorothioate oligodeoxyribonucleotide (PS-ODN) targeting simultaneously S. mutans gtfB and gtfC mRNAs in order to inhibit biofilm formation in vitro. Materials and methods. S. mutans bacteria were grown anaerobically on glass slides inserted vertically in 24-well cell culture plates containing Todd Hewitt broth with sucrose under exposure to antisense or missense PS-ODNs at the final concentration of 10 μM. Untreated bacteria served as controls. After 24 h of incubation, glass slides were removed, air-dried and further used for the quantitative evaluation of the streptococci biofilm applying an optical profilometry technique. Results. It was revealed that antisense PS-ODN considerably reduced the most critical biofilm surface roughness parameter Sa (average difference between the peak hight and valleys) inhibiting the biofilm development by 46% and 77% in comparison to untreated (p = 0.06) and missense PS-ODN-treated bacteria (p < 0.05), respectively. Conclusions. The results demonstrate that antisense PS-ODN considerably decreases streptococci-induced biofilm development on glass slides, and might therefore significantly suppress dental biofilm formation through simultaneous inactivation of S. mutans gtfB and gtfC mRNAs.

scholarly journals Modulation of Pseudomonas aeruginosa Biofilm Dispersal by a Cyclic-Di-GMP Phosphodiesterase with a Putative Hypoxia-Sensing Domain

2010 ◽  
Vol 76 (24) ◽  
pp. 8160-8173 ◽  
Author(s):  
Shuwen An ◽  
Ji'en Wu ◽  
Lian-Hui Zhang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Regulatory Protein ◽  
Phosphodiesterase Activity ◽  
Low Oxygen ◽  
Ggdef Domain ◽  
Biofilm Dispersal ◽  
Biofilm Development

ABSTRACT Pseudomonas aeruginosa encodes many enzymes that are potentially associated with the synthesis or degradation of the widely conserved second messenger cyclic-di-GMP (c-di-GMP). In this study, we show that mutation of rbdA, which encodes a fusion protein consisting of PAS-PAC-GGDEF-EAL multidomains, results in decreased biofilm dispersal. RbdA contains a highly conserved GGDEF domain and EAL domain, which are involved in the synthesis and degradation of c-di-GMP, respectively. However, in vivo and in vitro analyses show that the full-length RbdA protein only displays phosphodiesterase activity, causing c-di-GMP degradation. Further analysis reveals that the GGDEF domain of RbdA plays a role in activating the phosphodiesterase activity of the EAL domain in the presence of GTP. Moreover, we show that deletion of the PAS domain or substitution of the key residues implicated in sensing low-oxygen stress abrogates the functionality of RbdA. Subsequent study showed that RbdA is involved in positive regulation of bacterial motility and production of rhamnolipids, which are associated with biofilm dispersal, and in negative regulation of production of exopolysaccharides, which are required for biofilm formation. These data indicate that the c-di-GMP-degrading regulatory protein RbdA promotes biofilm dispersal through its two-pronged effects on biofilm development, i.e., downregulating biofilm formation and upregulating production of the factors associated with biofilm dispersal.

scholarly journals Reduction of Streptococcus mutans Adherence and Dental Biofilm Formation by Surface Treatment with Phosphorylated Polyethylene Glycol

2007 ◽  
Vol 51 (10) ◽  
pp. 3634-3641 ◽  
Author(s):  
Akira Shimotoyodome ◽  
Takashi Koudate ◽  
Hisataka Kobayashi ◽  
Junji Nakamura ◽  
Ichiro Tokimitsu ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
De Novo ◽  
Bacterial Attachment ◽  
Salivary Proteins ◽  
Dental Biofilm ◽  
Biofilm Development

ABSTRACT Initial attachment of the cariogenic Streptococcus mutans onto dental enamel is largely promoted by the adsorption of specific salivary proteins on enamel surface. Some phosphorylated salivary proteins were found to reduce S. mutans adhesion by competitively inhibiting the adsorption of S. mutans-binding salivary glycoproteins to hydroxyapatite (HA). The aim of this study was to develop antiadherence compounds for preventing dental biofilm development. We synthesized phosphorylated polyethylene glycol (PEG) derivatives and examined the possibility of surface pretreatment with them for preventing S. mutans adhesion in vitro and dental biofilm formation in vivo. Pretreatment of the HA surface with methacryloyloxydecyl phosphate (MDP)-PEG prior to saliva incubation hydrophilized the surface and thereby reduced salivary protein adsorption and saliva-promoted bacterial attachment to HA. However, when MDP-PEG was added to the saliva-pretreated HA (S-HA) surface, its inhibitory effect on bacterial binding was completely diminished. S. mutans adhesion onto S-HA was successfully reduced by treatment of the surface with pyrophosphate (PP), which desorbs salivary components from S-HA. Treatment of S-HA surfaces with MDP-PEG plus PP completely inhibited saliva-promoted S. mutans adhesion even when followed by additional saliva treatment. Finally, mouthwash with MDP-PEG plus PP prevented de novo biofilm development after thorough teeth cleaning in humans compared to either water or PP alone. We conclude that MDP-PEG plus PP has the potential for use as an antiadherence agent that prevents dental biofilm development.

scholarly journals Multiple Streptococcus mutans Genes Are Involved in Biofilm Formation

2002 ◽  
Vol 68 (12) ◽  
pp. 6283-6291 ◽  
Author(s):  
Akihiro Yoshida ◽  
Howard K. Kuramitsu
Keyword(s):  
Streptococcus Mutans ◽  
Dental Plaque ◽  
Biofilm Formation ◽  
Regulatory Gene ◽  
Hypothetical Protein ◽  
Abiotic Surfaces ◽  
Insertional Inactivation ◽  
Tooth Surfaces ◽  
Virulence Properties

ABSTRACT Streptococcus mutans has been strongly implicated as the principal etiological agent in dental caries. One of the important virulence properties of these organisms is their ability to form biofilms known as dental plaque on tooth surfaces. Since the roles of sucrose and glucosyltransferases in S. mutans biofilm formation have been well documented, we focused our attention on sucrose-independent factors. We have initially identified several mutants that appear to be defective in biofilm formation on abiotic surfaces by an insertional inactivation mutagenesis strategy applied to S. mutans. A total of 27 biofilm-defective mutants were isolated and analyzed in this study. From these mutants, three genes were identified. One of the mutants was defective in the Bacillus subtilis lytR homologue. Another of the biofilm-defective mutants isolated was a yulF homologue, which encodes a hypothetical protein of B. subtilis whose function in biofilm formation is unknown. The vast majority of the mutants were defective in the comB gene required for competence. We therefore have constructed and examined comACDE null mutants. These mutants were also found to be attenuated in biofilm formation. Biofilm formation by several other regulatory gene mutants were also characterized using an in vitro biofilm-forming assay. These results suggest that competence genes as well as the sgp and dgk genes may play important roles in S. mutans biofilm formation.

scholarly journals Bacterial lipopolysaccharides variably modulate in vitro biofilm formation of Candida species

2010 ◽  
Vol 59 (10) ◽  
pp. 1225-1234 ◽  
Author(s):  
H. M. H. N. Bandara ◽  
O. L. T. Lam ◽  
R. M. Watt ◽  
L. J. Jin ◽  
L. P. Samaranayake
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Significant Inhibition ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dependent Manner ◽  
Bacterial Lipopolysaccharides ◽  
Species Specific ◽  
Biofilm Development

The objective of this study was to evaluate the effect of the bacterial endotoxin LPS on Candida biofilm formation in vitro. The effect of the LPS of Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium on six different species of Candida, comprising Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA 646, was studied using a standard biofilm assay. The metabolic activity of in vitro Candida biofilms treated with LPS at 90 min, 24 h and 48 h was quantified by XTT reduction assay. Viable biofilm-forming cells were qualitatively analysed using confocal laser scanning microscopy (CLSM), while scanning electron microscopy (SEM) was employed to visualize the biofilm structure. Initially, adhesion of C. albicans was significantly stimulated by Pseudomonas and Klebsiella LPS. A significant inhibition of Candida adhesion was noted for the following combinations: C. glabrata with Pseudomonas LPS, C. tropicalis with Serratia LPS, and C. glabrata, C. parapsilosis or C. dubliniensis with Salmonella LPS (P<0.05). After 24 h of incubation, a significant stimulation of initial colonization was noted for the following combinations: C. albicans/C. glabrata with Klebsiella LPS, C. glabrata/C. tropicalis/C. krusei with Salmonella LPS. In contrast, a significant inhibition of biofilm formation was observed in C. glabrata/C. dubliniensis/C. krusei with Pseudomonas LPS, C. krusei with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. parapsilosis/C. dubliniensis /C. krusei with Salmonella LPS (P<0.05). On further incubation for 48 h, a significant enhancement of biofilm maturation was noted for the following combinations: C. glabrata/C. tropicalis with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. glabrata with Salmonella LPS, and a significant retardation was noted for C. parapsilosis/C. dubliniensis/C. krusei with Pseudomonas LPS, C. tropicalis with Serratia LPS, C. glabrata/C. parapsilosis/C. dubliniensis with Klebsiella LPS and C. dubliniensis with Salmonella LPS (P<0.05). These findings were confirmed by SEM and CLSM analyses. In general, the inhibition of the biofilm development of LPS-treated Candida spp. was accompanied by a scanty architecture with a reduced numbers of cells compared with the profuse and densely colonized control biofilms. These data are indicative that bacterial LPSs modulate in vitro Candida biofilm formation in a species-specific and time-dependent manner. The clinical and the biological relevance of these findings have yet to be explored.

scholarly journals Effects of pH on the Properties of Membrane Vesicles Including Glucosyltransferase in Streptococcus mutans

2021 ◽  
Vol 9 (11) ◽  
pp. 2308
Author(s):  
Yusuke Iwabuchi ◽  
Tomoyo Nakamura ◽  
Yasuka Kusumoto ◽  
Ryoma Nakao ◽  
Tsutomu Iwamoto ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Membrane Vesicles ◽  
Extracellular Dna ◽  
Tooth Surface ◽  
Initial Ph ◽  
Effects Of Ph ◽  
Low Levels ◽  
Quantitative Changes ◽  
Biofilm Development

Streptococcus mutans releases membrane vesicles (MVs) and induces MV-dependent biofilm formation. Glucosyltransferases (Gtfs) are bound to MVs and contribute to the adhesion and glucans-dependent biofilm formation of early adherent bacteria on the tooth surface. The biofilm formation of S. mutans may be controlled depending on whether the initial pH tends to be acidic or alkaline. In this study, the characteristics and effects of MVs extracted from various conditions {(initial pH 6.0 and 8.0 media prepared with lactic acid (LA) and acetic acid (AA), and with NaOH (NO), respectively)} on the biofilm formation of S. mutans and early adherent bacteria were investigated. The quantitative changes in glucans between primary pH 6.0 and 8.0 conditions were observed, associated with different activities affecting MV-dependent biofilm formation. The decreased amount of Gtfs on MVs under the initial pH 6.0 conditions strongly guided low levels of MV-dependent biofilm formation. However, in the initial pH 6.0 and 8.0 solutions prepared with AA and NO, the MVs in the biofilm appeared to be formed by the expression of glucans and/or extracellular DNA. These results suggest that the environmental pH conditions established by acid and alkaline factors determine the differences in the local pathogenic activities of biofilm development in the oral cavity.

scholarly journals Synergism of Streptococcus mutans and Candida albicans Reinforces Biofilm Maturation and Acidogenicity in Saliva: An In Vitro Study

2021 ◽  
Vol 10 ◽  
Author(s):  
Hye-Eun Kim ◽  
Yuan Liu ◽  
Atul Dhall ◽  
Marwa Bawazir ◽  
Hyun Koo ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Critical Role ◽  
In Vitro Study ◽  
Acidic Ph ◽  
Acidic Environment ◽  
Symbiotic Interaction ◽  
Biofilm Development

Early childhood caries, a virulent-form of dental caries, is painful, difficult, and costly to treat that has been associated with high levels of Streptococcus mutans (Sm) and Candida albicans (Ca) in plaque-biofilms on teeth. These microorganisms appear to develop a symbiotic cross-kingdom interaction that amplifies the virulence of plaque-biofilms. Although biofilm studies reveal synergistic bacterial-fungal association, how these organisms modulate cross-kingdom biofilm formation and enhance its virulence in the presence of saliva remain largely unknown. Here, we compared the properties of Sm and Sm-Ca biofilms cultured in saliva by examining the biofilm structural organization and capability to sustain an acidic pH environment conducive to enamel demineralization. Intriguingly, Sm-Ca biofilm is rapidly matured and maintained acidic pH-values (~4.3), while Sm biofilm development was retarded and failed to create an acidic environment when cultured in saliva. In turn, the human enamel slab surface was severely demineralized by Sm-Ca biofilms, while there was minimal damage to the enamel surface by Sm biofilm. Interestingly, Sm-Ca biofilms exhibited an acidic environment regardless of their hyphal formation ability. Our data reveal the critical role of symbiotic interaction between S. mutans and C. albicans in human saliva in the context of pathogenesis of dental caries, which may explain how the cross-kingdom interaction contributes to enhanced virulence of plaque-biofilm in the oral cavity.

scholarly journals IgY Targeting Bacterial Quorum-Sensing Molecules in Implant-Associated Infections

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 4027
Author(s):  
Ulrike Dapunt ◽  
Birgit Prior ◽  
Christopher Oelkrug ◽  
Jan Philippe Kretzer
Keyword(s):  
Quorum Sensing ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Major Complication ◽  
Underlying Mechanism ◽  
Bacterial Communication ◽  
Bacterial Quorum Sensing ◽  
Polysaccharide Intercellular Adhesion ◽  
Bacterial Quorum ◽  
Treatment Alternatives

Background: Implant-associated infections are still a major complication in the field of orthopedics. Bacteria can form biofilms on implant surfaces, making them more difficult to detect and treat. Since standard antibiotic therapy is often impaired in biofilm infections, particular interest is directed towards finding treatment alternatives. Biofilm-formation is a well-organized process during which bacteria communicate via quorum-sensing molecules (QSM). The aim of this study was to inhibit bacterial communication by directing avian IgY against specific QSM. Methods: Chicken were immunized against the following QSM: (1) AtlE, a member of the autolysin family which mediates attachment to a surface in Staphylococcus epidermidis; (2) GroEL, the bacterial heat shock protein; (3) PIA (polysaccharide intercellular adhesion), which is essential for cell–cell adhesion in biofilms. Staphylococcus epidermidis biofilms were grown and inhibition of biofilm-formation by IgYs was evaluated. Additionally, human osteoblasts were cultivated and biocompatibility of IgYs was tested. Results: We were able to demonstrate that all IgYs reduced biofilm-formation, also without prior immunization. Therefore, the response was probably not specific with regard to the QSM. Osteoblasts were activated by all IgYs which was demonstrated by microscopy and an increased release of IL-8. Conclusions: In conclusion, avian IgY inhibits biofilm-formation, though the underlying mechanism is not yet clear. However, adverse effects on local tissue cells (osteoblasts) were also observed.

scholarly journals Highly branched poly(N-isopropyl acrylamide) functionalized with an inducer molecule suppresses quorum sensing in Chromobacterium violaceum

2019 ◽  
Vol 55 (66) ◽  
pp. 9765-9768 ◽  
Author(s):  
Joanna Shepherd ◽  
Thomas Swift ◽  
Chien-Yi Chang ◽  
James R. Boyne ◽  
Stephen Rimmer ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Mode Of Action ◽  
Biofilm Formation ◽  
Chromobacterium Violaceum ◽  
Isopropyl Acrylamide ◽  
Bacterial Quorum Sensing ◽  
Bacterial Quorum

Bacterial quorum sensing has been implicated in a number of pathogenic bacterial processes, such as biofilm formation, making it a crucial target for developing materials with a novel antibiotic mode of action.

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