Strategies for Streptococcus mutans biofilm dispersal through extracellular polymeric substances disruption

A Nuclease from Streptococcus mutans Facilitates Biofilm Dispersal and Escape from Killing by Neutrophil Extracellular Traps

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2017.00097 ◽

2017 ◽

Vol 7 ◽

Cited By ~ 7

Author(s):

Jia Liu ◽

Luping Sun ◽

Wei Liu ◽

Lihong Guo ◽

Zhaohui Liu ◽

...

Keyword(s):

Streptococcus Mutans ◽

Neutrophil Extracellular Traps ◽

Extracellular Traps ◽

Biofilm Dispersal

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Role of extracellular polymeric substances in the adhesion interaction of Streptococcus mutans on TiO2 and SiO2 surfaces with different wettability

Colloids and Interface Science Communications ◽

10.1016/j.colcom.2020.100315 ◽

2020 ◽

Vol 39 ◽

pp. 100315

Author(s):

Gaoqi Wang ◽

Lei Chen ◽

Ding Weng ◽

Jiadao Wang

Keyword(s):

Streptococcus Mutans ◽

Extracellular Polymeric Substances ◽

Adhesion Interaction

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Competence-Stimulating-Peptide-Dependent Localized Cell Death and Extracellular DNA Production in Streptococcus mutans Biofilms

Applied and Environmental Microbiology ◽

10.1128/aem.02080-20 ◽

2020 ◽

Vol 86 (23) ◽

Author(s):

Ryo Nagasawa ◽

Tatsuya Yamamoto ◽

Andrew S. Utada ◽

Nobuhiko Nomura ◽

Nozomu Obana

Keyword(s):

Cell Death ◽

Single Cell ◽

Streptococcus Mutans ◽

Structural Stability ◽

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Imaging Techniques ◽

Extracellular Dna ◽

Content Type ◽

Cariogenic Bacterium

ABSTRACT Extracellular DNA (eDNA) is a biofilm component that contributes to the formation and structural stability of biofilms. Streptococcus mutans, a major cariogenic bacterium, induces eDNA-dependent biofilm formation under specific conditions. Since cell death can result in the release and accumulation of DNA, the dead cells in biofilms are a source of eDNA. However, it remains unknown how eDNA is released from dead cells and is localized within S. mutans biofilms. We focused on cell death induced by the extracellular signaling peptide called competence-stimulating peptide (CSP). We demonstrate that nucleic acid release into the extracellular environment occurs in a subpopulation of dead cells. eDNA production induced by CSP was highly dependent on the lytF gene, which encodes an autolysin. Although lytF expression was induced bimodally by CSP, lytF-expressing cells further divided into surviving cells and eDNA-producing dead cells. Moreover, we found that lytF-expressing cells were abundant near the bottom of the biofilm, even when all cells in the biofilm received the CSP signal. Dead cells and eDNA were also abundantly present near the bottom of the biofilm. The number of lytF-expressing cells in biofilms was significantly higher than that in planktonic cultures, which suggests that adhesion to the substratum surface is important for the induction of lytF expression. The deletion of lytF resulted in reduced adherence to a polystyrene surface. These results suggest that lytF expression and eDNA production induced near the bottom of the biofilm contribute to a firmly attached and structurally stable biofilm. IMPORTANCE Bacterial communities encased by self-produced extracellular polymeric substances (EPSs), known as biofilms, have a wide influence on human health and environmental problems. The importance of biofilm research has increased, as biofilms are the preferred bacterial lifestyle in nature. Furthermore, in recent years it has been noted that the contribution of phenotypic heterogeneity within biofilms requires analysis at the single-cell or subpopulation level to understand bacterial life strategies. In Streptococcus mutans, a cariogenic bacterium, extracellular DNA (eDNA) contributes to biofilm formation. However, it remains unclear how and where the cells produce eDNA within the biofilm. We focused on LytF, an autolysin that is induced by extracellular peptide signals. We used single-cell level imaging techniques to analyze lytF expression in the biofilm population. Here, we show that S. mutans generates eDNA by inducing lytF expression near the bottom of the biofilm, thereby enhancing biofilm adhesion and structural stability.

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Cell Wall Ultrastructure in Three Strains of a Cariogenic Streptococcus

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065730 ◽

1971 ◽

Vol 29 ◽

pp. 338-339

Author(s):

M. J. Kramer ◽

Alan L. Coykendall

Keyword(s):

Cell Wall ◽

Dental Caries ◽

Streptococcus Mutans ◽

Microscopic Study ◽

Electron Microscopic Study ◽

Genetic Heterogeneity ◽

Morphological Characteristics ◽

Electron Microscopic ◽

Dna Reassociation ◽

Wall Ultrastructure

During the almost 50 years since Streptococcus mutans was first suggested as a factor in the etiology of dental caries, a multitude of studies have confirmed the cariogenic potential of this organism. Streptococci have been isolated from human and animal caries on numerous occasions and, with few exceptions, they are not typable by the Lancefield technique but are relatively homogeneous in their biochemical reactions. An analysis of the guanine-cytosine (G-C) composition of the DNA from strains K-1-R, NCTC 10449, and FA-1 by one of us (ALC) revealed significant differences and DNA-DNA reassociation experiments indicated that genetic heterogeneity existed among the three strains. The present electron microscopic study had as its objective the elucidation of any distinguishing morphological characteristics which might further characterize the respective strains.

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The role of intracanal medicaments in inhibition of bacteria isolated from root canals of infected primary molars

Mustansiria Dental Journal ◽

10.32828/mdj.v14i1.766 ◽

2019 ◽

Vol 14 (1) ◽

pp. 92

Author(s):

Dr. Maha Abdul- Kareem Mahmood ◽

Dr. Huda Elias Ali ◽

Dr. Haraa Khairi Abdul-Kadher

Keyword(s):

Antimicrobial Activity ◽

Streptococcus Mutans ◽

Normal Saline ◽

Root Canal ◽

Primary Teeth ◽

Primary Molars ◽

Root Canals ◽

Etiologic Agents ◽

Micro Organisms

Microbes are considered as the primary etiologic agents in endodontic diseases.Disinfection of the root canal is obtained by the combined effect of biomechanicalpreparation, irrigation and intra canal medicament. The aim of the present study wasto assess the antimicrobial activity of intracanal medicaments (formocresol andEndosepton) against two micro organisms (Streptococcus mutans and staphylococcusaureus) isolated from 15 necrotic pulps of primary molars indicated for pulpectomyprocedure. The samples were cultured, and purified using microbiological evaluation.Broth dilution test was performed in our study by preparing test tubes containing10 ml of BHI broth (pH. 7) which then inoculated with strains of the tested bacteriaand incubated at 37 C° for 24 h. After over night incubaction, ten fold dilution weremade in test tubes containing 9 ml of normal saline by adding 1 ml of the inoculum tothe first tube . Then from dilution 10-1 , 0.1 ml of cell suspension was added to 9.9 mlof formocresol and endosepton, then 0.1 ml was taken and spread on duplicates ofBHI agar plates at different intervals and incubated aerobically for 24 h. at 37 C°.Colonies on the plates were counted after incubation and CFU/mL (colony formingunit) was calculated. Our results indicating that there were no significant differencesbetween the intracanal medicaments, but there were high significant differencesbetween the intervals time of the study. We concluded that both materials had greatantibacterial effect against the pathogens commonly isolated from necrotic pulpaltissue of primary teeth.

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