scholarly journals Concentration-dependent repression of the soluble and membrane components of the Streptococcus mutans phosphoenolpyruvate: sugar phosphotransferase system by glucose.

1989 ◽  
Vol 171 (6) ◽  
pp. 2942-2948 ◽  
Author(s):  
I R Hamilton ◽  
L Gauthier ◽  
B Desjardins ◽  
C Vadeboncoeur
Keyword(s):  
Streptococcus Mutans ◽  
Phosphotransferase System ◽  
Membrane Components

scholarly journals Two Closely Related ABC Transporters in Streptococcus mutans Are Involved in Disaccharide and/or Oligosaccharide Uptake

2007 ◽  
Vol 190 (1) ◽  
pp. 168-178 ◽  
Author(s):  
Alexander J. Webb ◽  
Karen A. Homer ◽  
Arthur H. F. Hosie
Keyword(s):  
Streptococcus Mutans ◽  
Abc Transporters ◽  
Sole Carbon Source ◽  
Binding Protein ◽  
Sugar Metabolism ◽  
System Component ◽  
Phosphotransferase System ◽  
Atpase Subunits ◽  
Membrane Components ◽  
Distinct Membrane

ABSTRACT Streptococcus mutans has a large number of transporters apparently involved in the uptake of carbohydrates. At least two of these, the multiple sugar metabolism transporter, MsmEFGK, and the previously uncharacterized MalXFGK, are members of the ATP-binding cassette (ABC) superfamily. Mutation analysis revealed that the MsmEFGK and MalXFGK transporters are principally involved in the uptake of distinct disaccharides and/or oligosaccharides. Furthermore, the data also indicated an unusual protein interaction between the components of these two related transporters. Strains lacking msmE (which encodes a solute binding protein) can no longer utilize raffinose or stachyose but grow normally on maltodextrins in the absence of MalT, a previously characterized EIImal phosphotransferase system component. In contrast, a mutant of malX (which encodes a solute binding protein) cannot utilize maltodextrins but grows normally on raffinose or stachyose. Radioactive uptake assays confirmed that MalX, but not MsmE, is required for uptake of [U-14C]maltotriose and that MalXFGK is principally involved in the uptake of maltodextrins with as many as 7 glucose units. Surprisingly, inactivation of the corresponding ATPase components did not result in an equivalent abolition of growth: the malK mutant can grow on maltotetraose as a sole carbon source, and the msmK mutant can utilize raffinose. We propose that the ATPase domains of these ABC transporters can interact with either their own or the alternative transporter complex. Such unexpected interaction of ATPase subunits with distinct membrane components to form complete multiple ABC transporters may be widespread in bacteria.

Inactivation of the Streptococcus mutans fxpC Gene Confers Resistance to Xylitol, a Caries-preventive Natural Carbohydrate Sweetener

2002 ◽  
Vol 81 (6) ◽  
pp. 380-386 ◽  
Author(s):  
H. Benchabane ◽  
L.-A. Lortie ◽  
N.D. Buckley ◽  
L. Trahan ◽  
M. Frenette
Keyword(s):  
Streptococcus Mutans ◽  
Northern Blot Analysis ◽  
Regulatory Protein ◽  
Open Reading Frames ◽  
Phosphotransferase System ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
Resistant Strains ◽  
Polymerase Chain ◽  
Reading Frames

Xylitol is transported by Streptococcus mutans via a constitutive phosphoenolpyruvate:fructose phosphotransferase system (PTS) composed of a IIABC protein. Spontaneous xylitol-resistant strains are depleted in constitutive fructose-PTS activity, exhibit additional phenotypes, and are associated with the caries-preventive properties of xylitol. Polymerase chain-reactions and chromosome walking were used to clone the fxp operon that codes for the constitutive fructose/xylitol-PTS. The operon contained three open reading frames: fxpA, which coded for a putative regulatory protein of the deoxyribose repressor (DeoR) family, fxpB, which coded for a 1-phosphofructokinase, and fxpC, which coded for a IIABC protein of the fructose-PTS family. Northern blot analysis revealed that these genes were co-transcribed into a 4.4-kb mRNA even in the absence of fructose. Inactivation of the fxpC gene conferred resistance to xylitol, confirming its function. The fxp operon is also present in the genomes of other xylitol-sensitive streptococci, which could explain their sensitivity to xylitol.

Phosphoenolpyruvate-Dependent Glucose Transport in Oral Streptococci

1973 ◽  
Vol 52 (6) ◽  
pp. 1209-1215 ◽  
Author(s):  
Charles F. Schachtele ◽  
John A. Mayo
Keyword(s):  
Glucose Uptake ◽  
Streptococcus Mutans ◽  
Glucose Transport ◽  
Enzyme System ◽  
Cell Suspensions ◽  
Oral Streptococci ◽  
Phosphotransferase System ◽  
Resting Cell

Streptococcus mutans, S sanguis, and S salivarius use a phosphoenolpyruvate (PEP)-dependent phosphotransferase system that results in phosphorylation of glucose at carbon 6. This enzyme system is not sensitive to fluoride. Glucose uptake into resting cell suspensions is sensitive to fluoride because of inhibition of intracellular PEP production. The glucose phosphotransferase system is constitutive in oral streptococci.

scholarly journals Effect of Xylitol on Growth of Streptococcus pneumoniae in the Presence of Fructose and Sorbitol

2001 ◽  
Vol 45 (1) ◽  
pp. 166-169 ◽  
Author(s):  
Terhi Tapiainen ◽  
Tero Kontiokari ◽  
Laura Sammalkivi ◽  
Irma Ikäheimo ◽  
Markku Koskela ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Growth Inhibition ◽  
Streptococcus Mutans ◽  
Otitis Media ◽  
Growth Medium ◽  
Acute Otitis Media ◽  
Antimicrobial Effect ◽  
Phosphotransferase System ◽  
Growth Impairment ◽  
Similar Growth

ABSTRACT Xylitol is effective in preventing acute otitis media by inhibiting the growth of Streptococcus pneumoniae. To clarify this inhibition we used fructose, which is known to block similar growth inhibition observed in Streptococcus mutans. In addition, we evaluated the efficacy of sorbitol in inhibiting the growth of pneumococci, as sorbitol is widely used for indications similar to those for which xylitol is used. The addition of 5% xylitol to the growth medium resulted in marked growth inhibition, an effect which was totally eliminated in the presence of 1, 2.5, or 5% fructose but not in the presence of 1 or 5% glucose, 1% galactose, or 1% sucrose. This finding implies that xylitol-induced inhibition of pneumococcal growth is mediated via the fructose phosphotransferase system in a way similar to that in which mutans group streptococcal growth is inhibited. The addition of sorbitol at concentrations of 1, 2.5, or 5% to the growth medium did not affect the growth of pneumococci and neither inhibited nor enhanced the xylitol-induced growth impairment. Thus, it seems that xylitol is the only commercially used sugar substitute proven to have an antimicrobial effect on pneumococci.

scholarly journals Green Tea-Derived Epigallocatechin Gallate Inhibits Acid Production and Promotes the Aggregation of Streptococcus mutans and Non-Mutans Streptococci

2021 ◽  
pp. 205-214
Author(s):  
Sili Han ◽  
Yuki Abiko ◽  
Jumpei Washio ◽  
Yufang Luo ◽  
Linglin Zhang ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Green Tea ◽  
Acid Production ◽  
Antimicrobial Properties ◽  
Epigallocatechin Gallate ◽  
Cell Aggregation ◽  
Mutans Streptococci ◽  
Sugar Uptake ◽  
Phosphotransferase System ◽  
Short Term

It has been suggested that green tea-derived epigallocatechin gallate (EGCG), which has antimicrobial properties, might help prevent dental caries. However, the detailed properties of EGCG remain unclear. In this study, the antimicrobial properties of EGCG were evaluated by examining its bactericidal activity, its inhibitory effects against bacterial growth, acid production, acidic end-product formation, and sugar uptake (phosphoenolpyruvate-dependent phosphotransferase system, PEP-PTS activity), and its effects on bacterial aggregation, using monocultured planktonic cells of <i>Streptococcus mutans</i> and non-mutans streptococci. Coincubating <i>S. mutans</i> with EGCG (1 mg/mL) for 4 h had no bactericidal effects, while it decreased the growth and acid production of <i>S. mutans</i> by inhibiting the activity of the PEP-PTS. EGCG (2 mg/mL) caused rapid bacterial cell aggregation and had reduced the optical density of <i>S. mutans</i> cell suspension by 86.7% at pH 7.0 and 90.7% at pH 5.5 after 2 h. EGCG also reduced the acid production of non-mutans streptococci, including <i>S. sanguinis</i>, <i>S. gordonii</i>, and <i>S. salivarius</i>, and promoted the aggregation of these non-mutans streptococci. Furthermore, these antimicrobial effects of short-term EGCG treatment persisted in the presence of saliva. These results suggest that EGCG might have short-term antibacterial effects on caries-associated streptococci in the oral cavity.

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