-
Scientific Reports Apr 2020Bacterial extracellular polymeric substances (EPSs) present diverse properties of biotechnological interest, such as surface modification, metal adsorption and...
Bacterial extracellular polymeric substances (EPSs) present diverse properties of biotechnological interest, such as surface modification, metal adsorption and hydrophobic substances solubilization through surface tension reduction. Thus, there is a growing demand for new producing strains and structurally variable biomolecules with different properties. One approach for scanning this biodiversity consists of exploring environments under selective pressures. The aim of this study was to evaluate the composition of culturable heterotrophic bacterial communities from five different sites from a copper mine in the Amazon biome by an enrichment technique to obtain metal resistant bacteria (lead, arsenic, cadmium, copper and zinc) capable of producing EPSs. The bacterial densities at the sites varied from 2.42 × 10 to 1.34 × 10 NMP mL and the 77 bacterial isolates obtained were classified in four divisions, β-Proteobacteria (16.88%), γ-Proteobacteria (7.29%), Firmicutes (61%) and Actinobacteria (12.98%). Bacillus, Alcaligenes, and Lysinibacillus were the most dominant among the 16 observed genera, but the relative frequency of each varied according to the sample and the metal used in the enrichment culture. 58% of the bacterial strains (45) could produce EPSs. From these, 33 strains showed emulsifying activity (E), and 9 of them reached values higher than 49%. Only Actinomyces viscosus E3.Pb5 and Bacillus subtilis group E3.As2 reduced the medium surface tension to values lower than 35 mN m. It was possible to confirm the high presence of bacteria capable of producing EPSs with tensoactive properties in Amazon copper mines and the evolutionary pressure exerted by the heavy metals during enrichment. These molecules can be tested as an alternative for use in processes that involve the removal of metals, such as the bioremediation of contaminated environments.
Topics: Arsenic; Bacteria; Biodegradation, Environmental; Brazil; Cadmium; Copper; Environmental Pollutants; Environmental Pollution; Extracellular Polymeric Substance Matrix; Heterotrophic Processes; Microbiota; Mining; RNA, Ribosomal, 16S; Soil Microbiology; Zinc
PubMed: 32277075
DOI: 10.1038/s41598-020-62780-8 -
Journal of Oral and Maxillofacial... 2019The Ayurvedic system of medicine is popular in India and has gone through various change and remains as the mainstay of medical relief to a large population. Dental...
INTRODUCTION
The Ayurvedic system of medicine is popular in India and has gone through various change and remains as the mainstay of medical relief to a large population. Dental caries is the one of the major issue in the recent time, and there is no definite caries prevention method so far apart from Topical fluoride application, regular oral hygiene measures, pit and fissure sealants and diet measure. In spite of the above mentioned preventive measures the people are still prone to dental caries. In order to find a better solution the present study evaluates the antimicrobial properties widely available and cost effective herbal extracts of Solanum xanthocarpum and Pistacia lentiscus extract on cariogenic oral microbial flora.
AIM
To Evaluate the Antimicrobial properties of Solanum xanthocarpum and Pistacia lentiscus extracts on cariogenic oral microbial flora.
METHODOLOGY
The antimicrobial properties of Solanum xanthocarpum and Pistacia lentiscus extracts on cariogenic oral microbial flora (streptococcus mutans, lactobacillus, actinomyces viscosus) by different culture techniques to estimate the zone of inhibition (well diffusion method) and minimum inhibitory concentration (tube dilution method).
RESULTS
The antimicrobial efficacy of Solanum xanthocarpum and Pistacia lentiscus on test bacteria were analysed using kurskal wallis test and values of 0.003 and 0.002 were obtained respectively, since the values were less than 0.005, indicating that both herbal products possess statistically significant antimicrobial properties.
CONCLUSION
The antimicrobial effects of the herbal extracts were almost on par with commercially available allopathic agents like chlorhexidine on oral cariogenic microbes. The efficacy should be further validated in a large scale studies and can be utilized for caries prevention in the form of mouth rinses, dentifrices and topical application in the future.
PubMed: 31942118
DOI: 10.4103/jomfp.JOMFP_30_19 -
Heliyon Dec 2019Dental caries is a multi-factorial oral disease, requiring a susceptible host, cariogenic microorganisms and suitable substrate. Caries is extended worldwide in spite of...
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: and as well as 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.
PubMed: 31886429
DOI: 10.1016/j.heliyon.2019.e03013 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... Jul 2019To construct antimicrobial peptides with potent antimicrobial activity, low cytotoxicity and efficient killing rate of for prevention and treatment of dental caries.
OBJECTIVE
To construct antimicrobial peptides with potent antimicrobial activity, low cytotoxicity and efficient killing rate of for prevention and treatment of dental caries.
METHODS
We exploited the existing design strategies to modify reutericin 6 or gassericin A produced by species in the oral cavity based on their cationicity, amphipathicity and -helical structure. We examined their antimicrobial activities using bacterial susceptibility assay, their cytotoxicity through cytotoxicity assay and their killing rate of with time-kill assay. We further evaluated the candidate derivatives for their killing rate against , their antimicrobial activity against different oral pathogens and the development of drug resistance.
RESULTS
We constructed 6 AT-1 derivatives, among which AT-7 showed an MIC of 3.3 μmol/L against , and with a killing rate of 88.7% against within 5 min. We did not obtain strains of resistant to AT- 7 after induction for 10 passages.
CONCLUSIONS
Hydrophobicity and imperfect amphipathic structure are two key parameters that define the antimicrobial potency of the antimicrobial peptides. The imperfectly amphipathic peptide AT-7 shows the potential for clinical application in dental caries treatment.
Topics: Anti-Infective Agents; Dental Caries; Humans; Microbial Sensitivity Tests; Peptides; Streptococcus mutans
PubMed: 31340916
DOI: 10.12122/j.issn.1673-4254.2019.07.12 -
Molecules (Basel, Switzerland) Jun 2019Synthesis of 1,2,3-triazole-substituted coumarins and also 1,2,3-triazolyl or 1,2,3-triazolylalk-1-inyl-linked coumarin-2,3-furocoumarin hybrids was performed by...
Synthesis of 1,2,3-triazole-substituted coumarins and also 1,2,3-triazolyl or 1,2,3-triazolylalk-1-inyl-linked coumarin-2,3-furocoumarin hybrids was performed by employing the cross-coupling and copper catalyzed azide-alkyne cycloaddition reaction approaches. The synthesized compounds were evaluated for their in vitro antibacterial activity against , , and bacterial strains. Coumarin-benzoic acid hybrids , and 3-((4-acetylamino-3-(methoxycarbonyl)phenyl)ethynyl)coumarin () showed promising activity against . strains, and the 1,2,3-triazolyloct-1-inyl linked coumarin-2,3-furocoumarin hybrid was endowed with high selectivity against and species. The in vitro antibacterial activity of , , and can potentially be compared with that of a number of modern antibiotic drugs used in the clinic, suggesting promising prospects for further research. A detailed study of the molecular interactions with the targeted protein MurB was performed using docking simulations and the obtained results are quite promising.
Topics: Anti-Bacterial Agents; Bacteria; Drug Design; Furocoumarins; Microbial Sensitivity Tests; Molecular Docking Simulation; Thermodynamics; Triazoles
PubMed: 31195697
DOI: 10.3390/molecules24112126 -
Letters in Applied Microbiology Apr 2019Candida-associated denture stomatitis presents as erythema of the palatal mucosa and is caused by biofilms containing the fungus Candida albicans that co-reside with...
Candida-associated denture stomatitis presents as erythema of the palatal mucosa and is caused by biofilms containing the fungus Candida albicans that co-reside with oral bacteria on the denture-fitting surface. This study aimed to assess the effect of several frequently encountered oral bacteria on the expression of C. albicans virulence factors in in vitro polymicrobial biofilms. Biofilms containing C. albicans and selected bacterial species were grown on denture acrylic, and analysed by microscopy and by qPCR for expression of putative virulence genes. Candida albicans-only biofilms showed limited hyphal production. Hyphal development was significantly (P < 0·001) increased when biofilms also contained four species of oral bacteria (Streptococcus sanguinis, Streptococcus gordonii, Actinomyces odontolyticus and Actinomyces viscosus), as was the expression of virulence genes (P < 0·05). Importantly, inclusion of Porphyromonas gingivalis in the biofilm consortium resulted in significant (P < 0·05) inhibition of virulence gene expression and production of hyphae. The in vitro expression of C. albicans virulence factors was modulated in polymicrobial biofilms. The complexity of this modulation was highlighted by the reversal of effects following introduction of a single bacterial species into a biofilm community. SIGNIFICANCE AND IMPACT OF THE STUDY: The impact of individual bacterial species on Candida albicans virulence highlights both the complexity of predicting infection mediated by polymicrobial communities and the potential for management through pro- or prebiotic therapy. The possibility to selectively modulate microbial virulence by addition of, or treatment with pro- or prebiotics avoids the use of conventional antimicrobial compounds, thus reducing the contribution to potential drug resistance. Understanding which bacterial species modulate virulence, and the mechanisms by which this occurs, particularly in biofilms, provides excellent foundations for further research questions, and the potential for novel clinical interventions.
Topics: Actinomyces; Biofilms; Candida albicans; Gene Expression Regulation, Fungal; Hyphae; Mouth; Porphyromonas gingivalis; Stomatitis, Denture; Streptococcus; Virulence; Virulence Factors
PubMed: 30825340
DOI: 10.1111/lam.13145 -
Journal of Applied Microbiology May 2019The purpose of this study was to conduct phytochemical analysis of sea buckthorn pulp oil and to evaluate the antimicrobial, anti-biofilm and antioxidant activities of...
AIM
The purpose of this study was to conduct phytochemical analysis of sea buckthorn pulp oil and to evaluate the antimicrobial, anti-biofilm and antioxidant activities of its mouthwash form.
METHODS AND RESULTS
Fatty acid composition of the sea buckthorn pulp oil was determined by GC-MS analysis, which revealed that, mono-unsaturated fatty acid, palmitoleic acid and saturated fatty acid, palmitic acid, were the major constituents. The antimicrobial and the anti-biofilm capacities of sea buckthorn pulp oil mouthwash form were evaluated against Streptococcus gordonii, Porphyromonas gingivalis, Actinomyces viscosus and Candida albicans, according to the European Norms, and the Biofilm Ring Test , respectively. These activities were then compared with those of chlorhexidine and herbal mouthwashes. The sea buckthorn-based mouthwash was bactericidal against S. gordonii and P. gingivalis, bacteriostatic against A. viscosus and showed no antifungal effect. Regardless of the strains used, complete inhibition of biofilm formation was achieved. The antioxidant activity of this experimental mouthwash was also assessed by DPPH and NBT assays.
CONCLUSION
Sea buckthorn mouthwash showed anti-biofilm activities against select single and multiple oral bacterial species.
SIGNIFICANCE AND IMPACT OF THE STUDY
In this study, a mouthwash derived from sea buckthorn (Hippophae rhamnoides) pulp oil has been experimented, for the first time, in order to overcome the problem of a large number of available synthetic mouthwashes which have side effects on teeth, gums and mucous membranes. This mouthwash seemed to be a suitable alternative for a preventive agent for periodontal inflammation.
Topics: Anti-Bacterial Agents; Bacteria; Hippophae; Humans; Microbial Viability; Mouth; Mouthwashes; Plant Extracts
PubMed: 30674068
DOI: 10.1111/jam.14210 -
Polish Journal of Microbiology 2018This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic... (Comparative Study)
Comparative Study
This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic therapy was carried out with a gallium aluminium arsenide laser (670 nm wavelength) using Toluidine blue O (TBO) as the photosensitizer. Cariogenic bacteria ( Streptococcus mutans , Lactobacillus casei , Streptococcus salivarius and Actinomyces viscosus ) were exposed to TBO and then to the laser for 1 minute in planktonic suspension. Then, tooth slices previously incubated for 24 hours with broth cultures of broth culture of the four cariogenic organisms were exposed to antimicrobial photosensitization. The control samples consisted of planktonic and sessile cells that were exposed to TBO alone, laser alone and the bacterial cells that were not treated with TBO or laser. The results showed significant reductions in the viability of S. mutans , L. casei and A. viscosus in both planktonic form (to 13%, 30%, and 55%, respectively) and sessile form hosted in dentinal tubules (to 19%, 13% and 52%, respectively), relative to the controls. S. salivarius was the least affected in planktonic (94% viability) and sessile form (86% viability). In conclusion, sensitivity to photosensitization is species-dependent and sessile biofilm cells are affected to the same extent as their planktonic counterparts. This study compared the outcome of photosensitization on the viability of four different cariogens in planktonic form as well as biofilms in human dentine. Photodynamic therapy was carried out with a gallium aluminium arsenide laser (670 nm wavelength) using Toluidine blue O (TBO) as the photosensitizer. Cariogenic bacteria (, , and ) were exposed to TBO and then to the laser for 1 minute in planktonic suspension. Then, tooth slices previously incubated for 24 hours with broth cultures of broth culture of the four cariogenic organisms were exposed to antimicrobial photosensitization. The control samples consisted of planktonic and sessile cells that were exposed to TBO alone, laser alone and the bacterial cells that were not treated with TBO or laser. The results showed significant reductions in the viability of , and in both planktonic form (to 13%, 30%, and 55%, respectively) and sessile form hosted in dentinal tubules (to 19%, 13% and 52%, respectively), relative to the controls. was the least affected in planktonic (94% viability) and sessile form (86% viability). In conclusion, sensitivity to photosensitization is species-dependent and sessile biofilm cells are affected to the same extent as their planktonic counterparts.
Topics: Adult; Biofilms; Dental Caries; Humans; Lacticaseibacillus casei; Microbial Viability; Photochemotherapy; Photosensitizing Agents; Streptococcus mutans; Streptococcus salivarius; Tolonium Chloride; Tooth; Young Adult
PubMed: 30550231
DOI: 10.21307/pjm-2018-053 -
The American Journal of Case Reports Nov 2018BACKGROUND Actinomyces species are normal flora of the upper respiratory, female genital, and gastrointestinal tract. Actinomyces species are generally considered to... (Review)
Review
Preterm Labor Caused by Hemolysis, Elevated Liver Enzymes, Low Platelet Count (HELLP) Syndrome and Postpartum Infection Complicated with Actinomyces Species: A Case Report.
BACKGROUND Actinomyces species are normal flora of the upper respiratory, female genital, and gastrointestinal tract. Actinomyces species are generally considered to have a low virulence potential. Here we report one case of Actinomyces viscosus isolated from a neonatal blood culture as a consequence of extreme prematurity in the presence of HELLP (hemolysis, elevated liver enzymes, low platelet count) syndrome. CASE REPORT A 23-week gestational age female infant was born to a 32-year-old mother. The pregnancy was complicated by severe HELLP syndrome leading to cesarean section at 23-week gestation. The initial blood culture grew anaerobic gram-positive branching rods consistent with Actinomyces species. Due to patient instability, antibiotic was started and continued for a total of 13 days. On day of life 26, the reference laboratory identified the organism as A. viscosus by 16S ribosomal RNA. CONCLUSIONS In this case, Actinomyces species was a consequence of HELLP syndrome and consecutive extreme prematurity. Further research to look more closely at Actinomyces species isolated from neonatal blood culture will help to elucidate the true significance of these isolates.
Topics: Actinomyces; Actinomycosis; Anti-Bacterial Agents; Cesarean Section; Female; Gestational Age; HELLP Syndrome; Humans; Infant, Extremely Premature; Pregnancy; Pregnancy Outcome; Pregnancy Trimester, Second
PubMed: 30420589
DOI: 10.12659/AJCR.911374 -
Journal of Ayurveda and Integrative... 2020Dental caries is a biofilm-related infectious disease with a multifactorial etiology, over five billion inhabitants have affected worldwide due to this disease.
BACKGROUND
Dental caries is a biofilm-related infectious disease with a multifactorial etiology, over five billion inhabitants have affected worldwide due to this disease.
OBJECTIVE
Antimicrobial efficacy of a mixed herbal powder extract (MHPE) against cariogenic microorganisms was investigated.
MATERIALS AND METHODS
MIC, MBC, kinetics of killing, biofilm disruption and anticaries effect of MHPE were determined. For biofilm disruption, biofilms of Streptococcus mutans, Lactobacillus casei, Actinomyces viscosus and Candida albicans were treated with MHPE for 30 min and attached cells were quantified after staining. For live/dead staining biofilm assay, S. mutans biofilm treated with MHPE for 1min, 5min and 1 h was examined with confocal laser scanning system after live/dead staining. Efficacy was experimented by structural quality using Scanning Electron Microscope (SEM). Anticaries effect was determined by formation of caries-like lesion in continuous flow biofilm model.
RESULTS
MHPE exhibited inhibition zones ranging from 12.5 to 24.0 mm. The highest inhibition zone was recorded at concentration of 50 μg/ml. MIC for S. mutans was between 12.23 and 36.7 μg/ml, while the MBC values ranged from 36.7 to 110.65 μg/ml. Inhibitory concentration of MHPE was three fold higher than CHLX. Significant reduction of cell count (49-95%) was observed with increasing time and higher concentration. Percentage biofilm reduction compare with negative control was 96.9% (A. viscosus), 94% (C. albicans), 99.8% (L. casei) and 91.7% (S. mutans). For MHPE-treated biofilm, live/dead staining demonstrated significant (p < 0.05) higher in deceased red fluorescence areas in all kinetics points from 53.6% (1min) to 85% (1h). SEM confirmed the damage in the outer layers of S. mutans. MHPE has components with effective antibacterial activity against caries-inducing microorganisms.
CONCLUSION
The anti-adherence and anti-biofilm effect as well as the faster killing activity suggests that MHPE formula has effective antibacterial activity and could be a useful source of anti-cariogenic agents in near future.
PubMed: 30389224
DOI: 10.1016/j.jaim.2018.01.005