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Cellular Microbiology Aug 2021Porphyromonas gulae, an animal-derived periodontal pathogen, expresses several virulence factors, including fimbria, lipopolysaccharide (LPS) and proteases. We...
Porphyromonas gulae, an animal-derived periodontal pathogen, expresses several virulence factors, including fimbria, lipopolysaccharide (LPS) and proteases. We previously reported that its invasive efficiency was dependent on fimbriae types. In addition, P. gulae LPS increased inflammatory responses via toll-like receptors. The present study was conducted to investigate the involvement of P. gulae proteases in bacterial and host cell biology. Porphyromonas gulae strains showed an ability to agglutinate mouse erythrocytes and also demonstrated co-aggregation with Actinomyces viscosus, while the protease inhibitors antipain, PMSF, TLCK and leupeptin diminished P. gulae proteolytic activity, resulting in inhibition of haemagglutination and co-aggregation with A. viscosus. In addition, specific proteinase inhibitors were found to reduce bacterial cell growth. Porphyromonas gulae inhibited Ca9-22 cell proliferation in a multiplicity of infection- and time-dependent manner. Additionally, P. gulae-induced decreases in cell contact and adhesion-related proteins were accompanied by a marked change in cell morphology from well spread to rounded. In contrast, inhibition of protease activity prevented degradation of proteins, such as E-cadherin, β-catenin and focal adhesion kinase, and also blocked inhibition of cell proliferation. Together, these results indicate suppression of the amount of human proteins, such as γ-globulin, fibrinogen and fibronectin, by P. gulae proteases, suggesting that a novel protease complex contributes to bacterial virulence.
Topics: Animals; Bacteroidaceae Infections; Fimbriae, Bacterial; Mice; Peptide Hydrolases; Porphyromonas; Porphyromonas gingivalis
PubMed: 33486854
DOI: 10.1111/cmi.13312 -
Journal of Periodontal Research Feb 2016Neutrophil extracellular trap (NET) release has generally been studied in the absence of serum, or at low concentrations of untreated or heat-inactivated serum. The...
BACKGROUND AND OBJECTIVES
Neutrophil extracellular trap (NET) release has generally been studied in the absence of serum, or at low concentrations of untreated or heat-inactivated serum. The influence of serum complement on NET release therefore remains unclear. We examined the DNA release induced by Staphylococcus aureus and three oral bacteria: Actinomyces viscosus, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum subsp. vincettii.
MATERIAL AND METHODS
Bacteria-stimulated NET release from the neutrophils of healthy donors was measured fluorometrically. Various complement containing and complement blocking conditions were used, including heat inactivation of the serum and antibody blockade of complement receptors 1 (CR1, CD35) and 3 (CR3, CD11b/CD18).
RESULTS
While the presence of serum markedly enhanced NET release induced by S. aureus, A. actinomycetemcomitans, and to a lesser extent by A. viscosus, there was no enhancement of NET release induced by F. nucleatum. The serum-mediated enhancement of NET release by A. actinomycetemcomitans was neutralized by heat inactivation of serum complement, while this was not the case for S. aureus. Blockade of CR1, significantly reduced NET release induced by S. aureus, A. actinomycetemcomitans and A. viscosus, while blockade of CR3, had no effect. However, opsonization of S. aureus with antibodies may also have contributed to the enhancing effect of serum, independently of complement, in that purified IgG promoted NET release.
CONCLUSIONS
In conclusion, complement opsonization promotes NET release induced by a variety of bacteria, including A. actinomycetemcomitans, and CR1 plays a dominant role in the process. Complement consumption or deficiency may compromise NETosis induced by some bacterial species, including A. actinomycetemcomitans. Within biofilms, the complement-inactivating abilities of some bacteria may protect other species against NETosis, while these are more vulnerable when adopting a planktonic lifestyle.
Topics: Complement System Proteins; Extracellular Traps; Macrophage-1 Antigen; Neutrophils; Receptors, Complement 3b; Staphylococcus aureus
PubMed: 25900429
DOI: 10.1111/jre.12284 -
Frontiers in Microbiology 2016In oral health, the interdental spaces are a real ecological niche for which the body has few or no alternative defenses and where the traditional daily methods for...
In oral health, the interdental spaces are a real ecological niche for which the body has few or no alternative defenses and where the traditional daily methods for control by disrupting biofilm are not adequate. The interdental spaces are the source of many hypotheses regarding their potential associations with and/or causes of cardiovascular disease, diabetes, chronic kidney disease, degenerative disease, and depression. This PCR study is the first to describe the interdental microbiota in healthy adults aged 18-35 years-old with reference to the Socransky complexes. The complexes tended to reflect microbial succession events in developing dental biofilms. Early colonizers included members of the yellow, green, and purple complexes. The orange complex bacteria generally appear after the early colonizers and include many putative periodontal pathogens, such as Fusobacterium nucleatum. The red complex (Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) was considered the climax community and is on the list of putative periodontal pathogens. The 19 major periodontal pathogens tested were expressed at various levels. F. nucleatum was the most abundant species, and the least abundant were Actinomyces viscosus, P. gingivalis, and Aggregatibacter actinomycetemcomitans. The genome counts for Eikenella corrodens, Campylobacter concisus, Campylobacter rectus, T. denticola, and Tannerella forsythensis increased significantly with subject age. The study highlights the observation that bacteria from the yellow complex (Streptococcus spp., S. mitis), the green complex (E. corrodens, Campylobacter gracilis, Capnocytophaga ochracea, Capnocytophaga sputigena, A. actinomycetemcomitans), the purple complex (Veillonella parvula, Actinomyces odontolyticus) and the blue complex (A. viscosus) are correlated. Concerning the orange complex, F. nucleatum is the most abundant species in interdental biofilm. The red complex, which is recognized as the most important pathogen in adult periodontal disease, represents 8.08% of the 19 bacteria analyzed. P. gingivalis was detected in 19% of healthy subjects and represents 0.02% of the interdental biofilm. T. forsythensis and T. denticola (0.02 and 0.04% of the interdental biofilm) were detected in 93 and 49% of healthy subjects, respectively. The effective presence of periodontal pathogens is a strong indicator of the need to develop new methods for disrupting interdental biofilm in daily oral hygiene.
PubMed: 27313576
DOI: 10.3389/fmicb.2016.00840 -
The Journal of Contemporary Dental... Jul 2018To study the antimicrobial effect of chlorhexidine diacetate (CHX-D)-modified type II glass ionomer cement (GIC) against the two predominant deep caries microorganisms,...
AIM
To study the antimicrobial effect of chlorhexidine diacetate (CHX-D)-modified type II glass ionomer cement (GIC) against the two predominant deep caries microorganisms, namely Lactobacillus casei and Actinomyces viscosus.
MATERIALS AND METHODS
An experimental GIC (ex-GIC) was prepared by mixing CHX-D powder with the powder of type II GIC to obtain 1% (w/w) concentration of CHX-D in the GIC. Antibacterial activity of this ex-GIC was tested against L. casei and A. viscosus using the agar diffusion method. The ex-GIC specimens were tested in their unset and set forms for each bacterium. For the unset group, specimens were placed in each agar plate immediately after manipulation and for the set group, specimens were placed in each agar plate, 1 hour after manipulation. The inhibition zones on the agar plate were recorded in millimeters immediately on placement of the specimen in the agar plate and after 48 hours. The reading was recorded and statistically analyzed for significant difference.
RESULTS
Mann-Whitney U test showed statistically significant difference in the inhibition zones produced by ex-GIC against L. casei and A. viscosus when both were compared in unset (p-value = 0.002) and set (p-value = 0.031) groups. For both the groups, the zone of inhibition against L. casei was greater. Though the unset group recorded wider zone of inhibition, the difference was not significant when compared with the respective set group. This was true for both the bacterial groups.
CONCLUSION
The 1% CHX-D-modified type II GIC showed antibacterial property against L. casei and A. viscosus and significantly higher activity against L. casei.
CLINICAL SIGNIFICANCE
Addition of 1% CHX-D to type II GIC showed evidence of antibacterial activity against organisms found in deep carious lesion and therefore may exhibit superior antimicrobial efficiency when used as an intermediate therapeutic restoration in deep cavities.
Topics: Actinomyces viscosus; Agar; Anti-Bacterial Agents; Chlorhexidine; Dental Caries; Dose-Response Relationship, Drug; Drug Resistance, Bacterial; Glass Ionomer Cements; Humans; Lacticaseibacillus casei; Microbial Sensitivity Tests
PubMed: 30066686
DOI: No ID Found -
Journal of Endodontics Aug 2016Enterococcus faecalis is the most frequently detected species in root canal-treated teeth, and it is able to survive under starvation conditions. However, persistent...
The Starvation Resistance and Biofilm Formation of Enterococcus faecalis in Coexistence with Candida albicans, Streptococcus gordonii, Actinomyces viscosus, or Lactobacillus acidophilus.
INTRODUCTION
Enterococcus faecalis is the most frequently detected species in root canal-treated teeth, and it is able to survive under starvation conditions. However, persistent periapical disease is often caused by multispecies. The aim of this study was to explore the survival of E. faecalis in starvation conditions and biofilm formation with the 4 common pathogenic species.
METHODS
A dual-species model of Candida albicans, Streptococcus gordonii, Actinomyces viscosus, or Lactobacillus acidophilus in combination with E. faecalis was established and allowed to grow in phosphate-buffered saline for the examination of starvation survival. Cefuroxime sodium and vancomycin at a concentration of 100 mg/L were added into brain-heart infusion plate agar to count the 2 bacteria separately in the dual species. Scanning electron microscopy was used to observe the dual species and multiple species on the root canal dentin of bovine teeth for 48 hours. A confocal laser scanning microscope was used to show the 4 groups of dual-species biofilms on substrates with glass bottoms for 48 hours.
RESULTS
E. faecalis was more resistant to starvation in coexistence with C. albicans, S. gordonii, A. viscosus, or L. acidophilus, and S. gordonii was completely inhibited in coexistence with E. faecalis. The dual-species biofilm showed that E. faecalis formed thicker and denser biofilms on the root canal dentin and glass slides in coexistence with S. gordonii and A. viscosus than C. albicans and L. acidophilus.
CONCLUSIONS
The multispecies community is conducive to the resistance to starvation of E. faecalis and biofilm formation in root canals.
Topics: Actinomyces viscosus; Animals; Anti-Bacterial Agents; Bacteriological Techniques; Biofilms; Candida albicans; Cattle; Colony Count, Microbial; Dental Pulp Cavity; Enterococcus faecalis; Lactobacillus acidophilus; Microbial Consortia; Microbial Viability; Microscopy, Confocal; Microscopy, Electron, Scanning; Streptococcus gordonii
PubMed: 27316318
DOI: 10.1016/j.joen.2016.05.002 -
Nefrologia : Publicacion Oficial de La... 2017
PubMed: 28750877
DOI: 10.1016/j.nefro.2017.01.001 -
Materials (Basel, Switzerland) Oct 2021Peri-implantitis (PI) is a relatively frequent pathology that compromises the overall survival of the dental implant. Adjunctive approaches for the conventional...
Peri-implantitis (PI) is a relatively frequent pathology that compromises the overall survival of the dental implant. Adjunctive approaches for the conventional mechanical debridement are being suggested to optimize the treatment of PI. The goal of the study was the assessment of the disinfection potential of the Q-Switch Nd: YAG laser on contaminated titanium implant surfaces. A total of 72 sterile titanium discs were used and divided into three groups: 24 contaminated titanium discs treated with the laser (study Group L), 24 contaminated titanium discs with no treatment (control 1-Group C), and 24 sterile titanium discs with no treatment (control 2-Group S). Multi-species biofilm was used: Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Streptococcus mutans, Streptococcus sobrinus, and Prevotella intermedia. Commensal bacteria were included also: Actinomyces naeslundii, Actinomyces viscosus, Streptococcus cristatus, Streptococcus gordonii, Streptococcus mitis, Streptococcus oralis, Streptococcus sanguinis, Streptococcus parasanguinis, and Veillonella parvula. Parameters delivered per pulse on the targeted surfaces of the titanium discs were an energy density of 0.597 J/cm each pulse, a pulse power of 270 mW, a laser beam spot of 2.4 mm in diameter, and a rate of repetition of 10 Hertz (Hz) for a pulse duration of 6 nanoseconds (ns). The mode was no contact, and a distance of 500 micrometers was used with a total time of irradiation equal to 2 s (s). The collection of microbiological samples was made for all groups; colony-forming units (CFU) were identified by two different practitioners, and the average of their examinations was considered for each sample. The average of the TBC (CFU/mL) was calculated for each group. Values were 0.000 CFU/mL, 4767 CFU/mL, and 0.000 CFU/mL for Group L, Group C, and Group S, respectively. Therefore, the suggested treatment protocol was able to provoke a total disinfection of the contaminated titanium surfaces. A statistical difference was only found between Group L vs. Group C and between Group S vs. Group C. The difference was not significant between Group S and Group L. In conclusion, the present study confirmed that the Q-Switch Nd: YAG laser under our specific conditions can provide a total disinfection of the contaminated titanium surfaces.
PubMed: 34683666
DOI: 10.3390/ma14206078 -
Archives of Oral Biology Sep 2015The pathogenesis of Candida-associated stomatitis involves the dysfunction of flora antagonistic to Candida. Oral Actinomyces species play an important role in...
OBJECTIVE
The pathogenesis of Candida-associated stomatitis involves the dysfunction of flora antagonistic to Candida. Oral Actinomyces species play an important role in regulating the oral microecological balance. The objective of this study was to investigate the antagonism of three oral Actinomyces against Candida albicans.
DESIGN
Suspensions, culture supernatants and bacterial lysates of Actinomyces viscosus, Actinomyces naeslundii and Actinomyces odontolyticus were investigated for their actions upon C. albicans. In addition to a commercial strain, six clinical strains of C. albicans were also tested. The proliferation of C. albicans was assessed using a liquid co-cultivation assay. The adhesion, acid protease and extracellular phospholipase activity, hyphae growth, and biofilm formation of C. albicans were measured.
RESULTS
The results showed that the suspensions, culture supernatants and cell lysates of 10(8) colony forming units/ml oral Actinomyces significantly inhibited the proliferation of C. albicans (all P<0.001). The culture supernatants exhibited significant antagonistic interactions in terms of adhesion (A. viscosus P<0.001, A. naeslundii P=0.016 and A. odontolyticus P=0.009), acid protease (A. viscosus P=0.035, A. naeslundii P=0.022, A. odontolyticus P<0.001) and phospholipase activities (A. viscosus P=0.011, A. naeslundii P=0.042, A. odontolyticus P=0.021) of Candida, as well as its hyphae growth (A. viscosus P=0.002, A. naeslundii P=0.008, A. odontolyticus P=0.006). Inhibition of C. albicans biofilm formation was also observed.
CONCLUSIONS
This study provides preliminary evidence that oral Actinomyces have inhibitory effects on the proliferation, adhesion, metabolic enzyme activity, hyphae formation and biofilm development of C. albicans.
Topics: Actinomyces; Bacterial Adhesion; Biofilms; Candida albicans; Candidiasis, Oral; Cell Proliferation; Humans; In Vitro Techniques; Virulence
PubMed: 26143096
DOI: 10.1016/j.archoralbio.2015.06.015 -
Bratislavske Lekarske Listy 2016The antibacterial activity of conventional glass ionomer cement against three different microorganism strains alone and following incorporation of 1, 2 and 3%...
OBJECTIVES
The antibacterial activity of conventional glass ionomer cement against three different microorganism strains alone and following incorporation of 1, 2 and 3% Benzalkonium Chloride and Cetylpyridinium Chloride was evaluated.
METHODS
Agar diffusion method was used to determine the inhibitory effect of the conventional glass ionomer cement ChemFlex on Streptococcus mutans, Lactobacillus casei and Actinomyces viscosus. Bacterial strains were inoculated into BHIB, and incubated in an anaerobic atmosphere (37 °C). From the bacteria grown in the liquid medium, the density of the inoculum was set to be equivalent to McFarland 2 standard. In Shaedler agar, 350 μL of the bacterial suspension were equally spread. Specimens (4 mm × 6 mm) were prepared from the cement without and with addition of 1, 2 and 3% Benzalkonium Chloride and Cetylpyridinium Chloride. The inhibition zones were determined after 48 hours, after 2, 7 and 21 days of incubation.
RESULTS
The combination ChemFlex + Benzalkonium Chloride has the best effect on the three analysed bacteria. The Benzalkonium Chloride antibacterial compound has a stronger antibacterial effect than Cetylpyridinium Chloride.
CONCLUSIONS
Glass ionomer cements can potentially be used as a medium for slow release of active antimicrobial components, and they have the potential to improve clinical outcomes of the cements (Tab. 3, Fig. 3, Ref. 31).
Topics: Anti-Bacterial Agents; Benzalkonium Compounds; Cetylpyridinium; Glass Ionomer Cements; Gram-Positive Bacteria; Microbial Sensitivity Tests
PubMed: 26810167
DOI: 10.4149/bll_2016_007 -
International Journal of Clinical and... 2015To explore the fluorescence characteristics of common cariogenic bacteria: Streptococcus mutans, S. sanguis, Actinomyces viscosus, Prevotella intermedia, Lactobacillus...
OBJECTIVE
To explore the fluorescence characteristics of common cariogenic bacteria: Streptococcus mutans, S. sanguis, Actinomyces viscosus, Prevotella intermedia, Lactobacillus acidophilus, and Candida albicans.
METHODS
The bacteria were cultured on brain heart infusion (BHI) agar and BHI blood agar, and bacterial colonies were collected for further amplification in liquid medium. Bacterial suspensions in physiological saline were equally divided into three parts for bacteria counting, fluorescence spectrometry detection, and fluorescence microscope examination.
RESULTS
The optimal excitation wavelength of the bacteria was 350 nm; their characteristic fluorescence peak position was at 436 ± 4 nm. There was a significant linear correlation between fluorescence intensity and bacterial concentration. The mean optical density (MOD) of S. mutans and L. acidophilus cultivated in BHI blood was significantly higher than that cultivated in BHI agar (110 ± 10 vs. 57 ± 20; 94 ± 16 vs. 31 ± 12, respectively, P < 0.05). The MOD of S. sanguis, A. viscosus, and P. intermedia cultivated in BHI blood agar was higher than that cultivated in BHI agar (37 ± 12 vs. 36 ± 11; 43 ± 17 vs. 38 ± 6; 86 ± 21 vs. 72 ± 8, respectively, P > 0.05); the opposite was observed for C. albicans.
CONCLUSION
At 350 nm excitation wavelength, 436 ± 4 nm is an indicator for detecting six cariogenic bacteria. The fluorescence energy, Q, is a valuable index reflecting bacterial concentration under fluorescence spectrometry detection. Exogenous fluorescence groups have greater influence on fluorescence intensity and little influence on fluorescence peak position detection.
PubMed: 26064260
DOI: No ID Found