Characteristics of oral methicillin-resistant Staphylococcus epidermidis isolated from dental plaque

Tang, Boyu; Gong, Tao; Cui, Yujia; Wang, Lingyun; He, Chao; Lu, Miao; Chen, Jiamin; Jing, Meiling; Zhang, Anqi; Li, Yuqing

doi:10.1038/s41368-020-0079-5

Cited by 25 publications

(19 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The structural composition of the biofilm was observed and relatively quantified by in situ labeling of bacterial cells and EPS as described previously [ 54 ]. After incubation with Alexa Fluor 647-labeled dextran conjugate (1 μM; Life Technologies, Grand Island, NY, USA), the supernatant was discarded, and the biofilm was rinsed with sterile PBS three times.…”

Section: Methodsmentioning

confidence: 99%

Acetylation of glucosyltransferases regulates Streptococcus mutans biofilm formation and virulence

Pan

Yang

et al. 2021

PLoS Pathog

Self Cite

View full text Add to dashboard Cite

Lysine acetylation is a frequently occurring post-translational modification (PTM), emerging as an important metabolic regulatory mechanism in prokaryotes. This process is achieved enzymatically by the protein acetyltransferase (KAT) to specifically transfer the acetyl group, or non-enzymatically by direct intermediates (acetyl phosphate or acetyl-CoA). Although lysine acetylation modification of glucosyltransferases (Gtfs), the important virulence factor in Streptococcus mutans, was reported in our previous study, the KAT has not been identified. Here, we believe that the KAT ActG can acetylate Gtfs in the enzymatic mechanism. By overexpressing 15 KATs in S. mutans, the synthesized water-insoluble extracellular polysaccharides (EPS) and biofilm biomass were measured, and KAT (actG) was identified. The in-frame deletion mutant of actG was constructed to validate the function of actG. The results showed that actG could negatively regulate the water-insoluble EPS synthesis and biofilm formation. We used mass spectrometry (MS) to identify GtfB and GtfC as the possible substrates of ActG. This was also demonstrated by in vitro acetylation assays, indicating that ActG could increase the acetylation levels of GtfB and GtfC enzymatically and decrease their activities. We further found that the expression level of actG in part explained the virulence differences in clinically isolated strains. Moreover, overexpression of actG in S. mutans attenuated its cariogenicity in the rat caries model. Taken together, our study demonstrated that the KAT ActG could induce the acetylation of GtfB and GtfC enzymatically in S. mutans, providing insights into the function of lysine acetylation in bacterial virulence and pathogenicity.

show abstract

Section: Methodsmentioning

confidence: 99%

Acetylation of glucosyltransferases regulates Streptococcus mutans biofilm formation and virulence

Pan

Yang

et al. 2021

PLoS Pathog

Self Cite

View full text Add to dashboard Cite

show abstract

“…Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were conducted to evaluate the characteristic of S. mutans biofilms and planktonic bacteria as previously described (Li et al 2019; Tang et al 2020; see Appendix for details).…”

Section: Methodsmentioning

confidence: 99%

EpsR Negatively Regulates Streptococcus mutans Exopolysaccharide Synthesis

et al. 2021

View full text Add to dashboard Cite

Streptococcus mutans is considered the primary etiological agent of human dental caries. Glucosyltransferases (Gtfs) from S. mutans play important roles in the formation of biofilm matrix and the development of cariogenic oral biofilm. Therefore, Gtfs are considered an important target to prevent the development of dental caries. However, the role of transcription factors in regulating gtf expression is not yet clear. Here, we identify a MarR (multiple antibiotic resistance regulator) family transcription factor named EpsR (exopolysaccharide synthesis regulator), which negatively regulates gtfB expression and exopolysaccharide (EPS) production in S. mutans. The epsR in-frame deletion strain grew slowly, aggregated more easily in the presence of dextran, and displayed different colony morphology and biofilm structure. Notably, epsR deletion resulted in altered 3-dimensional biofilm architecture, increased water-insoluble EPS production, and upregulated GtfB protein content and activity. In addition, global gene expression profiling revealed differences in the expression levels of 69 genes in which gtfB was markedly upregulated. The conserved DNA motif for EpsR binding was determined by electrophoretic mobility shift assay and DNase I footprinting assays. Moreover, analysis of β-galactosidase activity suggested that EpsR acted as a repressor and inhibited gtfB expression. Taken together, our findings indicate that EpsR is an important transcription factor that regulates gtfB expression and EPS production in S. mutans. These results add new aspects to the complexity of regulating the expression of genes involved in the cariogenicity of S. mutans, which might lead to novel strategies to prevent the formation of cariogenic biofilm that may favor diseases.

show abstract

“…The biofilm structure of S. mutans strains was examined by confocal laser scanning microscopy (CLSM) analysis. Overnight cultures of bacteria were diluted 1:10 by BHI broth and grown to OD 600 = 0.5; then the cells were diluted 1:100 into fresh BHI broth supplemented with 1% sucrose (w/v) and grown on a μ‐Slide culture plate (Ibidi GmbH, Germany) for 12 h. Bacterial cells were labeled with nucleic acid dye SYTO 9 (Invitrogen, United States), and extracellular polymeric matrix (EPS) was labeled by Alexa Fluor 647 (Invitrogen, USA) (Tang et al., 2020). CLSM (Olympus FV3000, Japan) was used to study the biofilm structure layer by layer under ×60 oil immersion lens.…”

Section: Methodsmentioning

confidence: 99%

The Adc regulon mediates zinc homeostasis in Streptococcus mutans

Pan

Yang

Chen

et al. 2021

Molecular Oral Microbiology

Self Cite

View full text Add to dashboard Cite

Zinc (Zn2+) is an essential divalent trace metal for living cells. Intracellular zinc homeostasis is critical to the survival and virulence of bacteria. Thus, the frequent fluctuations of salivary zinc, caused by the low physiological level and the frequent exogenous zinc introduction, present a serious challenge for bacteria colonizing the oral cavity. However, the regulation strategies to keep intracellular Zn2+ homeostasis in Streptococcus mutans, an important causative pathogen of dental caries, are unknown. Because zinc uptake is primarily mediated by an ATP‐binding ABC transporter AdcABC in Streptococcus strains, we examined the function of AdcABC and transcription factor AdcR in S. mutans in this study. The results demonstrated that deletion of either adcA or adcCB gene impaired the growth but enhanced the extracellular polymeric matrix production in S. mutans, both of which could be relieved after excessive Zn2+ supplementation. Using RNA sequencing analysis, quantitative reverse transcription polymerase chain reaction examination, LacZ‐reporter studies, and electrophoretic mobility shift assay, we showed that a MarR (multiple antibiotic resistance regulator) family transcription factor, AdcR, negatively regulates the expression of the genes adcR, adcC, adcB, and adcA by acting on the adcRCB and adcA promoters in response to Zn2+ concentration in their environmental niches. The deletion of adcR increases the sensitivity of S. mutans to excessive Zn2+ supply. Taken together, our findings suggest that Adc regulon, which consists of a Zn2+ uptake transporter AdcCBA and a Zn2+‐responsive repressor AdcR, plays a prominent role in the maintenance of intracellular zinc homeostasis of S. mutans.

show abstract

Characteristics of oral methicillin-resistant Staphylococcus epidermidis isolated from dental plaque

Cited by 25 publications

References 55 publications

Acetylation of glucosyltransferases regulates Streptococcus mutans biofilm formation and virulence

Acetylation of glucosyltransferases regulates Streptococcus mutans biofilm formation and virulence

EpsR Negatively Regulates Streptococcus mutans Exopolysaccharide Synthesis

The Adc regulon mediates zinc homeostasis in Streptococcus mutans

Contact Info

Product

Resources

About