Antimicrobial peptides Pep19–2.5 and Pep19-4LF inhibit Streptococcus mutans growth and biofilm formation

ABSTRACTPotassium (K+) is the most abundant cation in the fluids of dental biofilm. The biochemical and biophysical functions of K+and a variety of K+transport systems have been studied for most pathogenic bacteria but not for oral pathogens. In this study, we establish the modes of K+acquisition inStreptococcus mutansand the importance of K+homeostasis for its virulence attributes. TheS. mutansgenome harbors four putative K+transport systems that included two Trk-like transporters (designated Trk1 and Trk2), one glutamate/K+cotransporter (GlnQHMP), and a channel-like K+transport system (Kch). Mutants lacking Trk2 had significantly impaired growth, acidogenicity, aciduricity, and biofilm formation. [K+] less than 5 mM eliminated biofilm formation inS. mutans. The functionality of the Trk2 system was confirmed by complementing anEscherichia coliTK2420 mutant strain, which resulted in significant K+accumulation, improved growth, and survival under stress. Taken together, these results suggest that Trk2 is the main facet of the K+-dependent cellular response ofS. mutansto environment stresses.IMPORTANCEBiofilm formation and stress tolerance are important virulence properties of caries-causingStreptococcus mutans. To limit these properties of this bacterium, it is imperative to understand its survival mechanisms. Potassium is the most abundant cation in dental plaque, the natural environment ofS. mutans. K+is known to function in stress tolerance, and bacteria have specialized mechanisms for its uptake. However, there are no reports to identify or characterize specific K+transporters inS. mutans. We identified the most important system for K+homeostasis and its role in the biofilm formation, stress tolerance, and growth. We also show the requirement of environmental K+for the activity of biofilm-forming enzymes, which explains why such high levels of K+would favor biofilm formation.

Download Full-text

A Real-Time Thermal Sensor System for Quantifying the Inhibitory Effect of Antimicrobial Peptides on Bacterial Adhesion and Biofilm Formation

Sensors ◽

10.3390/s21082771 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2771

Author(s):

Tobias Wieland ◽

Julia Assmann ◽

Astrid Bethe ◽

Christian Fidelak ◽

Helena Gmoser ◽

...

Keyword(s):

Antimicrobial Peptides ◽

Real Time ◽

Bacterial Adhesion ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Bovine Mastitis ◽

Inhibitory Effect ◽

Thermal Sensor ◽

Bacterial Cells ◽

Static Conditions

The increasing rate of antimicrobial resistance (AMR) in pathogenic bacteria is a global threat to human and veterinary medicine. Beyond antibiotics, antimicrobial peptides (AMPs) might be an alternative to inhibit the growth of bacteria, including AMR pathogens, on different surfaces. Biofilm formation, which starts out as bacterial adhesion, poses additional challenges for antibiotics targeting bacterial cells. The objective of this study was to establish a real-time method for the monitoring of the inhibition of (a) bacterial adhesion to a defined substrate and (b) biofilm formation by AMPs using an innovative thermal sensor. We provide evidence that the thermal sensor enables continuous monitoring of the effect of two potent AMPs, protamine and OH-CATH-30, on surface colonization of bovine mastitis-associated Escherichia (E.) coli and Staphylococcus (S.) aureus. The bacteria were grown under static conditions on the surface of the sensor membrane, on which temperature oscillations generated by a heater structure were detected by an amorphous germanium thermistor. Bacterial adhesion, which was confirmed by white light interferometry, caused a detectable amplitude change and phase shift. To our knowledge, the thermal measurement system has never been used to assess the effect of AMPs on bacterial adhesion in real time before. The system could be used to screen and evaluate bacterial adhesion inhibition of both known and novel AMPs.

Download Full-text

A Novel Gene Involved in the Survival of Streptococcus mutans under Stress Conditions

Applied and Environmental Microbiology ◽

10.1128/aem.02549-13 ◽

2013 ◽

Vol 80 (1) ◽

pp. 97-103 ◽

Cited By ~ 11

Author(s):

Dan Li ◽

Yukie Shibata ◽

Toru Takeshita ◽

Yoshihisa Yamashita

Keyword(s):

Streptococcus Mutans ◽

Streptococcus Pyogenes ◽

Biofilm Formation ◽

Acid Tolerance ◽

Stress Conditions ◽

Insertion Mutagenesis ◽

Trna Modification ◽

Content Type ◽

Virulence Proteins ◽

Random Insertion

ABSTRACTAStreptococcus mutansmutant defective in aciduricity was constructed by random-insertion mutagenesis. Sequence analysis of the mutant revealed a mutation ingidA, which is known to be involved in tRNA modification inStreptococcus pyogenes. Complementation ofgidAbyS. pyogenesgidArecovered the acid tolerance ofS. mutans. Although thegidA-inactivatedS. pyogenesmutant exhibited significantly reduced expression of multiple extracellular virulence proteins, theS. mutansmutant did not. On the other hand, thegidAmutant ofS. mutansshowed reduced ability to withstand exposure to other stress conditions (high osmotic pressure, high temperature, and bacitracin stress) besides an acidic environment. In addition, loss of GidA decreased the capacity for glucose-dependent biofilm formation by over 50%. This study revealed thatgidAplays critical roles in the survival ofS. mutansunder stress conditions, including lower pH.

Download Full-text

Effect of a Berry Polyphenolic Fraction on Biofilm Formation, Adherence Properties and Gene Expression of Streptococcus mutans and Its Biocompatibility with Oral Epithelial Cells

Antibiotics ◽

10.3390/antibiotics10010046 ◽

2021 ◽

Vol 10 (1) ◽

pp. 46

Author(s):

Mariem Souissi ◽

Amel Ben Lagha ◽

Kamel Chaieb ◽

Daniel Grenier

Keyword(s):

Epithelial Cells ◽

Streptococcus Mutans ◽

Biofilm Formation ◽

Cell Model ◽

Pcr Analysis ◽

Adhesion Properties ◽

Oral Epithelial Cells ◽

Polymerase Chain ◽

Oral Epithelial ◽

Wild Blueberry

The ability of Streptococcus mutans to adhere to oral surfaces and form biofilm is a key step in the tooth decay process. The aim of this study was to investigate a berry (wild blueberry, cranberry, and strawberry) polyphenolic fraction, commercialized as Orophenol®, for its antibacterial, anti-biofilm, and anti-adhesion properties on S. mutans. Moreover, the biocompatibility of the fraction with human oral epithelial cells was assessed. Phenolic acids, flavonoids (flavonols, anthocyanins, flavan-3-ols), and procyanidins made up 10.71%, 19.76%, and 5.29% of the berry polyphenolic fraction, respectively, as determined by chromatography and mass spectrometry. The berry polyphenolic preparation dose-dependently inhibited S. mutans biofilm formation while not reducing bacterial growth. At concentrations ranging from 250 to 1000 µg/mL, the fraction inhibited the adhesion of S. mutans to both saliva-coated hydroxyapatite and saliva-coated nickel–chrome alloy. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis showed that incubating S. mutans with the berry polyphenolic fraction was associated with a reduced expression of luxS gene, which regulates quorum sensing in S. mutans. The berry fraction did not show any significant cytotoxicity in an oral epithelial cell model. In conclusion, Orophenol®, which is a mixture of polyphenols from wild blueberry, cranberry and strawberry, possesses interesting anti-caries properties while being compatible with oral epithelial cells.

Download Full-text

Mediterranean herb extracts inhibit microbial growth of representative oral microorganisms and biofilm formation of Streptococcus mutans

PLoS ONE ◽

10.1371/journal.pone.0207574 ◽

2018 ◽

Vol 13 (12) ◽

pp. e0207574 ◽

Cited By ~ 5

Author(s):

Joachim Hickl ◽

Aikaterini Argyropoulou ◽

Maria Eleni Sakavitsi ◽

Maria Halabalaki ◽

Ali Al-Ahmad ◽

...

Keyword(s):

Streptococcus Mutans ◽

Biofilm Formation ◽

Microbial Growth ◽

Herb Extracts ◽

Oral Microorganisms

Download Full-text

The Effects of Surface Roughness of Composite Resin on Biofilm Formation of Streptococcus mutans in the Presence of Saliva

Operative Dentistry ◽

10.2341/11-371-l ◽

2012 ◽

Vol 37 (5) ◽

pp. 532-539 ◽

Cited By ~ 36

Author(s):

JW Park ◽

CW Song ◽

JH Jung ◽

SJ Ahn ◽

JL Ferracane

Keyword(s):

Surface Roughness ◽

Silicon Carbide ◽

Streptococcus Mutans ◽

Biofilm Formation ◽

Composite Resin ◽

Resin Composite ◽

Fluid Phase ◽

Confocal Laser ◽

Carbohydrate Source ◽

Effect Of Surface

SUMMARY The purpose of this study was to investigate the effects of surface roughness of resin composite on biofilm formation of Streptococcus mutans in the presence of saliva. To provide uniform surface roughness on composites, disks were prepared by curing composite against 400-grit silicon carbide paper (SR400), 800-grit silicon carbide paper (SR800), or a glass slide (SRGlass). The surface roughness was examined using confocal laser microscopy. For biofilm formation, S. mutans was grown for 24 hours with each disk in a biofilm medium with either glucose or sucrose in the presence of fluid-phase or surface-adsorbed saliva. The adherent bacteria were quantified via enumeration of the total viable counts of bacteria. Biofilms were examined using scanning electron microscopy. This study showed that SR400 had deeper and larger, but fewer depressions than SR800. Compared to SRGlass and SR800, biofilm formation was significantly increased on SR400. In addition, the differences in the effect of surface roughness on the amount of biofilm formation were not significantly influenced by either the presence of saliva or the carbohydrate source. Considering that similar differences in surface roughness were observed between SR400 and SR800 and between SR800 and SRGlass, this study suggests that surface topography (size and depth of depressions) may play a more important role than surface roughness in biofilm formation of S. mutans.

Download Full-text

Effects of sub-minimum inhibitory concentrations of antimicrobial agents on Streptococcus mutans biofilm formation

International Journal of Antimicrobial Agents ◽

10.1016/j.ijantimicag.2012.01.009 ◽

2012 ◽

Vol 39 (5) ◽

pp. 390-395 ◽

Cited By ~ 47

Author(s):

Liping Dong ◽

Zhongchun Tong ◽

Dake Linghu ◽

Yuan Lin ◽

Rui Tao ◽

...

Keyword(s):

Streptococcus Mutans ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Minimum Inhibitory Concentrations

Download Full-text

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

Microorganisms ◽

10.3390/microorganisms9112308 ◽

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.

Download Full-text