Sugar Allocation to Metabolic Pathways is Tightly Regulated and Affects the Virulence of Streptococcus mutans

Abstract

Bacteria take up and metabolize sugar as a carbohydrate source for survival. Most bacteria can utilize many sugars, including glucose, sucrose, and galactose, as well as amino sugars, such as glucosamine and N-acetylglucosamine. After entering the cytoplasm, the sugars are mainly allocated to the glycolysis pathway (energy production) and to various bacterial component biosynthesis pathways, including the cell wall, nucleic acids and amino acids. Sugars are also utilized to produce several virulence factors, such as capsule and lipoteichoic acid. Glutamine-fructose-6-phosphate aminotransferase (GlmS) and glucosamine-6-phosphate deaminase (NagB) have crucial roles in sugar distribution to the glycolysis pathway and to cell wall biosynthesis. In Streptococcus mutans, a cariogenic pathogen, the expression levels of glmS and nagB are coordinately regulated in response to the presence or absence of amino sugars. In addition, the disruption of this regulation affects the virulence of S. mutans. The expression of nagB and glmS is regulated by NagR in S. mutans, but the precise mechanism underlying glmS regulation is not clear. In Staphylococcus aureus and Bacillus subtilis, the mRNA of glmS has ribozyme activity and undergoes self-degradation at the mRNA level. However, there is no ribozyme activity region on glmS mRNA in S. mutans. In this review article, we summarize the sugar distribution, particularly the coordinated regulation of GlmS and NagB expression, and its relationship with the virulence of S. mutans.

Isobaric Tags for Relative and Absolute Quantitation Proteomics Analysis of Gene Regulation by SprC in Staphylococcus Aureus

“…In Streptococcus mutans, the alteration of NagB expression can affect the virulence of the bacteria [44], but the corresponding role in S. aureus remains unclear. Another protein affected by SprC is undecaprenyl diphosphate synthase, which is crucial for peptidoglycan biosynthesis and consequently influences bacterial cell growth.…”

Streptococcus mutans and Actinomyces naeslundii Interaction in Dual-Species Biofilm

“…The species studied included a key species for the maintenance of biofilm ecological balance that can also be present in incipient or radicular caries (A. naeslundii) and Streptococcus mutans, considered one of the most important cariogenic species [20][21][22][23][24]. The results of the present study showed that interactions between S. mutans and A. naeslundii occur during early stages of biofilm formation, leading to a decrease in lactic acid production and to a higher resistance of S. mutans to chlorhexidine exposure.…”

“…Substantial efforts have been dedicated to understanding S. mutans virulence factors [20][21][22][23] because this species is strongly associated with dental caries [24]. However, with the deeper understanding of microbial physiology within biofilms, the importance of bacterial interaction for dental biofilm cariogenicity has been recognized.…”

Combination of dynamic turbidimetry and tube agglutination to identify procoagulant genes by transposon mutagenesis in Staphylococcus aureus

“…The gene cydA encodes ubiquinone cytochrome oxidase subunit I, which is involved in bacterial electron transfer chain, and there are no studies in S.aureus that electron transfer are involved in coagulase production, although energy production genes still affect virulence factors expression [23,24] . Our studies proved that SaeRS system, ClfA, Coa and Ebh genes are essential in plasma agglutination in S.aureus [25-27] , and our research had same results.…”