Influence of time, toothpaste and saliva in the retention of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes

Screening Antibacterial Constituents of Scutellaria Radix Based on Spectrum-Effect Relationships Between HPLC Fingerprints and the Inhibition of Oral Bacteria

Scutellaria Radix (SR) is a widely used traditional Chinese medicine in clinics for the therapy of upper respiratory tract infectious diseases. Modern pharmacological investigations indicate that SR exerts a significant bacteriostatic effect on different oral bacteria, but few studies have systematically investigated the main active constituents of SR causing this activity. Spectrum-effect correlation analysis was applied to screening anti-oral-microbial constituents from SR. The aqueous extract of SR was divided into fractions of different polarity and the active fraction was screened using the agar diffusion method. Eighteen batches of SR were further prepared and the chromatography fingerprint was established using high-performance liquid chromatography. The antibacterial activities of these constituents were examined against different oral bacteria. Finally, the spectrum-effect relationship between the fingerprint and those antibacterial effects was analyzed by gray correlation analysis and partial least squares regression. Five active constituents were screened out and their antibacterial activity was systematically confirmed by a knockout/in strategy combined with a biofilm extraction method, which indicated that these five compounds were responsible for the antibacterial activity of SR. These results form the basis for further development and improved quality control of SR in the treatment of oral diseases.

The role of toothbrush in the transmission of corona- and influenza viruses - results of an in vitro study

Objectives

The aim of this in vitro study was to investigate viruses’ stabilities on manual toothbrushes using feline coronavirus (FeCoV) as representative of coronaviruses and an Avian influenza A virus H1N1 for influenza viruses.

Material and methods

Two viruses, FeCoV (Strain Munich; titer 107.5 TCID50/ml) and H1N1 (RE 230/90; titer 106.5 TCID50/ml), were used in this study. Manual toothbrushes were disassembled into bristles, bristle fixation, and back of the toothbrush head, contaminated with the viruses and air-dried for 24 h. In a second experiment, whole toothbrush heads were contaminated, rinsed with water (5 ml for 15 s) and then air-dried.

Results

For FeCoV, immediately after contamination, the following average titers were recovered: fixation: 10^6.41, back of head: 10^6.81 and bristles: 10^6.63 TCID₅₀/ml. Following air-drying of 12 (fixation) and 24 h, titers of ≤ 10^2.5, 10^3.75, and 10^2.72 TCID₅₀/ml were found in the respective groups, with a detection limit of 10^2.5 TCID₅₀/ml. For H1N1, immediately after contamination, the following average titers could be recovered: fixation: 10^5.53, back of head: 10^5.97 and bristles: 10^5.75 TCID₅₀/ml. Following air-drying of 8 (fixation) and 24 h, titers were ≤ 10^2.5, 10^3.63, and 10^3.53 TCID₅₀/ml in the respective group, again with 10^2.5 TCID₅₀/ml being the detection limit. In case of water rinse, no infectious virus could be recovered after 12 h.

Conclusion

Viral load of both viruses is reduced by air-drying, especially following water rinsing.

Clinical relevance

The toothbrush itself plays an insignificant role in the self-transmission of coronavirus and influenza virus.

Contamination of antimicrobial-resistant bacteria on toothbrushes used with mechanically ventilated patients: A cross sectional study

OBJECTIVE

The purpose of this study was to determine pathogenic and antimicrobial-resistant bacteria on used toothbrushes of mechanically ventilated patients.

RESEARCH METHODOLOGY

A cross-sectional study was conducted by collecting toothbrushes used with mechanically ventilated patients. The total bacterial count on each toothbrush was assessed by culturing on Trypticase soy agar (TSA). Gram stain and biochemical testing were used to identify bacterial species. Antibiotic susceptibility of pathogenic bacteria was assessed by the Kirby-Bauer disk diffusion method.

RESULTS

Thirty-five toothbrushes (97%) had bacterial contamination, 27 toothbrushes had at least two bacterial species, and 13 toothbrushes harboured antimicrobial-resistant bacteria. The most commonly isolated bacteria were Klebsiella spp. (21%), followed by Acinetobacter baumannii (18%). Five isolates of A. baumannii, six isolates of K. pneumoniae, and two isolates of Enterobacter cloacae were multidrug-resistant (MDR) strains. Four isolates of K. pneumoniae were identified as extended-spectrum beta-lactamase (ESBL) producing strains, and two isolates of P. aeruginosa were extensively drug-resistant (XDR). The average total bacterial count was 10⁴-10⁵ CFU/toothbrush head.

CONCLUSIONS

Antimicrobial-resistant bacteria were detected on toothbrushes. Therefore, practice of toothbrush care should be reconsidered in associated to maintaining the oral hygiene of mechanically ventilated patients to prevent ventilator-associated pneumonia (VAP).

Effect of flavonoids on antimicrobial activity of microorganisms present in dental plaque

PURPOSE

Dental caries is a multi-factorial oral disease, requiring a susceptible host, cariogenic microorganisms and suitable substrate. Caries is extended worldwide in spite of the availability of countless prophylactic means, including fluoride toothpaste and dental sealers. Many efforts have been made to achieve isolation of pure natural products for medicinal use. Flavonoids are bioactive polyphenol compounds possessing multidimensional effects such as antibacterial action.

METHODS

The present study targeted the characterization of antibacterial and antifungal activity of various flavonoids (apigenin, catechin, luteolin, morin, myricetin, naringin, quercetin and rutin). Nine strains present in dental plaque were used: Agreggatibacter actinomycetemcomitans, Actinomyces naeslundii, Actinomyces viscosus, Enterococcus faecalis, Escherichia coli, Lactobacillus casei, Staphylococcus aureus, Streptococcus oralis and Streptococcus sanguinis as well as Candida albicans fungal strain.

RESULTS

Results revealed that luteolin, morin, naringin, quercetin and rutin effectively inhibited bacterial and fungal growth. However, morin was the most effective flavonoid.

CONCLUSION

It might then be concluded that flavonoids show bacteriostatic effect on all of tested bacteria and fungus.

Influence of Helicobacter pylori culture supernatant on the ecological balance of a dual-species oral biofilm

Dental caries is a chronic progressive disease occurring in the tooth hard tissue due to multiple factors, in which bacteria are the initial cause. Both Streptococcus mutans and Streptococcus sanguinis are main members of oral biofilm. Helicobacter pylori may also be detected in dental plaque, playing an important role in the development of dental caries.

OBJECTIVE

The aim of this study was to investigate the effect of H. pylori culture supernatant on S. mutans and S. sanguinis dual-species biofilm and to evaluate its potential ability on affecting dental health.

MATERIAL AND METHODS

The effect of H. pylori supernatant on single-species and dual-species biofilm was measured by colony forming units counting and fluorescence in situ hybridization (FISH) assay, respectively. The effect of H. pylori supernatant on S. mutans and S. sanguinis extracellular polysaccharides (EPS) production was measured by both confocal laser scanning microscopy observation and anthrone-sulfuric acid method. The effect of H. pylori supernatant on S. mutans gene expression was measured by quantitative real-time PCR (qRT-PCR) assays.

RESULTS

H. pylori supernatant could inhibit both S. mutans and S. sanguinis biofilm formation and EPS production. S. sanguinis inhibition rate was significantly higher than that of S. mutans. Finally, S. mutans bacteriocin and acidogenicity related genes expression were affected by H. pylori culture supernatant.

CONCLUSION

Our results showed that H. pylori could destroy the balance between S. mutans and S. sanguinis in oral biofilm, creating an advantageous environment for S. mutans, which became the dominant bacteria, promoting the formation and development of dental caries.

Efficacy of various side-to-side toothbrushes and impact of brushing parameters on noncontact biofilm removal in an interdental space model

OBJECTIVES

The objective of this study was to evaluate the efficacy of four different side-to-side toothbrushes and the impact of various brushing parameters on noncontact biofilm removal in an adjustable interdental space model.

MATERIALS AND METHODS

A three-species biofilm, consisting of Porphyromonas gingivalis, Fusobacterium nucleatum, and Streptococcus sanguinis, was formed in vitro on protein-coated titanium disks using a flow chamber combined with a static biofilm growth model. Subsequently, the biofilm-coated disks were exposed to four different powered toothbrushes (A, B, C, D). The parameters distance (0 and 1 mm), brushing time (2, 4, and 6 s), interdental space width (1, 2, and 3 mm), and toothbrush angulation (45° and 90°) were tested. The biofilm volumes were determined using volumetric analyses with confocal laser scanning microscope (Zeiss LSM700) images and Imaris version 7.7.2 software.

RESULTS

The median percentages of simulated interdental biofilm reduction by the tested toothbrushes ranged from 7 to 64 %. The abilities of the analyzed toothbrushes to reduce the in vitro biofilm differed significantly (p < 0.05). Three of the tested toothbrushes (A, B, C) were able to significantly reduce a simulated interdental biofilm by noncontact brushing (p ≤ 0.005). The brushing parameters and their combinations tested in the experiments revealed only minor effects on in vitro interdental biofilm reduction (p > 0.05).

CONCLUSIONS

A three-species in vitro biofilm could be altered by noncontact brushing with toothbrushes A, B, and C in an artificial interdental space model.

CLINICAL RELEVANCE

Certain side-to-side toothbrushes demonstrate in vitro a high efficacy in interdental biofilm removal without bristle-to-biofilm contact.