Antimicrobial activities of a small molecule compound II-6s against oral streptococci

Front. Cell. Infect. Microbiol.

Lyu

Zhang

et al. 2022

Self Cite

Oral microbial dysbiosis is the major causative factor for common oral infectious diseases including dental caries and periodontal diseases. Interventions that can lessen the microbial virulence and reconstitute microbial ecology have drawn increasing attention in the development of novel therapeutics for oral diseases. Antimicrobial small molecules are a series of natural or synthetic bioactive compounds that have shown inhibitory effect on oral microbiota associated with oral infectious diseases. Novel small molecules, which can either selectively inhibit keystone microbes that drive dysbiosis of oral microbiota or inhibit the key virulence of the microbial community without necessarily killing the microbes, are promising for the ecological management of oral diseases. Here we discussed the research progress in the development of antimicrobial small molecules and delivery systems, with a particular focus on their antimicrobial activity against typical species associated with oral infectious diseases and the underlying mechanisms.

Section: Small Molecules That Inhibit Keystone Bacteria Associated Wi...mentioning

confidence: 93%

“…MIC 90 : 3.91 mg/ml(Zhang J et al, 2021) MBC 90 : 15.63 mg/ml MBIC 90 : 3.91 mg/ml MBRC 90 : 62.5 mg/ml inhibit the demineralization of tooth enamel and induce no drug resistance in S…”

mentioning

confidence: 99%

The Application of Small Molecules to the Control of Typical Species Associated With Oral Infectious Diseases

Front. Cell. Infect. Microbiol.

Lyu

Zhang

et al. 2022

Self Cite

“…It been confirmed that S. mutans can develop high levels of resistance to it [ 12 , 13 ]. Chlorhexidine, which is the gold standard for controlling dental plaque clinically, acts on bacterial cell walls and induces strain resistance in S. mutans [ 14 ]. The imperceptible low-frequency resistance of the drug may be due to its multiple different targets [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

The suppression effect of SCH-79797 on Streptococcus mutans biofilm formation

Zhang

Journal of Oral Microbiology

Qiu

et al. 2022

Background SCH-79797 was recently shown to be a broad-spectrum antibacterial agent with a dual-bactericidal mechanism. However, its anti-biofilm effect remains unknown. Purpose To investigate the effect of SCH-79797 on the biofilm formation of the cariogenic Streptococcus mutans Methods and Results Crystal violet staining, colony forming units count and MTT assays (for cell metabolic activity) revealed that S. mutans biofilm formation was significantly suppressed. In addition, virulence factors, including extracellular polysaccharides (investigated by bacterial/exopolysaccharide staining and the anthrone method) and acid production (investigated by lactic acid and supernatant pH detection) were also inhibited significantly. Moreover, the biofilm inhibitory effect of SCH-79797 was mediated through its repression of bacterial growth and not by a bactericidal effect, which was verified by growth curve and bacterial live/ dead staining, respectively. Quantitative real-time PCR results disclosed that SCH-79797 affected bacterial acid production and tolerance, polysaccharide synthesis and remodeling, biofilm formation and quorum sensing-related gene expression. In addition, SCH-79797 showed good biocompatibility as determined by cytotoxicity assays. Conclusion SCH-79797 had an anti-biofilm effect and showed application prospects in the control of dental caries.

“…In addition, a simultaneous association with drug resistance and tolerance has been reported. For instance, reports suggest that chlorhexidine induces drug resistance in S. mutans, and the fungus Candida albicans may produce persisters after treatment with chlorhexidine [10,11]. In addition, the indiscriminate bactericidal effect of chlorhexidine would dramatically affect the microecology of oral microflora.…”

Section: Introductionmentioning

confidence: 99%

Regulatory Effect of Irresistin-16 on Competitive Dual-Species Biofilms Composed of Streptococcus mutans and Streptococcus sanguinis

Wang

et al. 2022

Pathogens

Based on the ecological plaque hypothesis, suppressing opportunistic pathogens within biofilms, rather than killing microbes indiscriminately, could be a biofilm control strategy for managing dental caries. The present study aimed to evaluate the effects of irresistin-16 (IRS-16) on competitive dual-species biofilms, which consisted of the conditional cariogenic agent Streptococcus mutans (S. mutans) and oral commensal bacteria Streptococcus sanguinis (S. sanguinis). Bacterial growth and biofilm formation were monitored using growth curve and crystal violet staining, respectively. The microbial proportion was determined using fluorescence in situ hybridization. A 2, 5-diphenyltetrazolium bromide assay was used to measure the metabolic activity of biofilms. Bacterial/extracellular polysaccharide (EPS) dyeing, together with water-insoluble EPS measurements, were used to estimate EPS synthesis. A lactic acid assay was performed to detect lactic acid generation in biofilms. The cytotoxicity of IRS-16 was evaluated in mouse fibroblast L929 cells using a live/dead cell viability assay and cell counting kit-8 assay. Our results showed that IRS-16 exhibited selective anti-biofilm activity, leading to a remarkable survival disadvantage of S. mutans within competitive dual-species biofilms. In addition, the metabolic activity, EPS synthesis, and acid generation of dual-species biofilms were significantly reduced by IRS-16. Moreover, IRS-16 showed minimal cytotoxicity against mouse fibroblast L929 cells. In conclusion, IRS-16 exhibited remarkable regulatory effects on dual-species biofilms composed of S. mutans and S. sanguinis with low cytotoxicity, suggesting that it may have potential for use in caries management through ecological biofilm control.