Oral Pathogenic Bacteria Research Articles

Phytochemical composition and in vitro screening of the antimicrobial activity of essential oils on oral pathogenic bacteria

In this study, the activity of essential oils (EOs) against microorganisms involved in oral diseases was evaluated. Fourteen EOs were selected and subjected to gas chromatographic analysis, including Illicium verum, Eucaliptus globulus, Eugenia caryophyllata, Leptospermum scoparium, Mentha arvensis, Mentha piperita, Myrtus communis, Salvia officinalis, Melaleuca alternifolia, Rosmarinus officinalis, Lavandula x intermedia, Thymus capitatus and Thymus vulgaris. These EOs were tested for their antimicrobial activity on Streptococcus mutans and Lactobacillus species clinically isolated from dental surgery patients. The antibacterial activity was evaluated by means of the disc diffusion and the minimum inhibitory concentration (MIC). Five EOs, having shown an interesting antimicrobial activity, were selected for a second screening in combination between them and with chlorhexidine. From the second assays, two EO–EO and three EO-chlorhexidine associations gave interesting results as potential constituents of mouthwashes, especially for the contribution of oxygenated monoterpenes, including menthol, thymol and carvacrol.

Antimicrobial Effects of Mastic Extract Against Oral and Periodontal Pathogens.

Various antimicrobial agents are widely used in the therapy of oral inflammatory diseases. However, their side effects and the appearance of drug resistance justify research on natural antimicrobial agents to target oral pathogens that are safe for the host. In the present study, antimicrobial properties of mastic extract on commensal and pathogenic oral bacteria, as well as its possible cytotoxic effect toward cells of epithelial and mesenchymal origin, were evaluated and compared with the common antimicrobial agents hydrogen peroxide (H2O2) and chlorhexidine digluconate (CHX). Oral and periodontal pathogens (Porphyromonas gingivalis, Streptococcus mutans [Sm], Streptococcus oralis, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, and Prevotella nigrescens) were treated with different concentrations of mastic extract, 3% H2O2, and 0.2% CHX, and evaluated with an agar diffusion test. The cytotoxic effect of mastic extract was tested on four cell lines of epithelial and mesenchymal origin (HaCaT, SaOS-2, MC3T3-E1, periodontal ligament [PDL] cells) by neutral red and 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide assay. Mastic extract led to significantly (P ≤0.016) increased inhibition of the tested periodontal pathogens compared with H2O2. No effect of mastic extract was observed on Sm. Mastic extract showed beneficial effects on cell viability because viability values of tested cells were significantly (P ≤0.016) lower for cells treated with CHX and H2O2 compared with mastic extract-treated cells after stimulation for 2, 4, and 6 hours. The present data demonstrate mastic extract's inhibition of periodontal pathogens, as well as beneficial effects on cell viability, compared with H2О2, suggesting that it could be considered an alternative antibacterial agent in the prevention of periodontal disease.

Potential applications of nonthermal plasmas against biofilm-associated micro-organisms invitro.

Biofilms as complex microbial communities attached to surfaces pose several challenges in different sectors, ranging from food and healthcare to desalination and power generation. The biofilm mode of growth allows microorganisms to survive in hostile environments and biofilm cells exhibit distinct physiology and behaviour in comparison with their planktonic counterparts. They are ubiquitous, resilient and difficult to eradicate due to their resistant phenotype. Several chemical-based cleaning and disinfection regimens are conventionally used against biofilm-dwelling micro-organisms invitro. Although such approaches are generally considered to be effective, they may contribute to the dissemination of antimicrobial resistance and environmental pollution. Consequently, advanced green technologies for biofilm control are constantly emerging. Disinfection using nonthermal plasmas (NTPs) is one of the novel strategies having a great potential for control of biofilms of a broad spectrum of micro-organisms. This review discusses several aspects related to the inactivation of biofilm-associated bacteria and fungi by different types of NTPs under invitro conditions. A brief introduction summarizes prevailing methods in biofilm inactivation, followed by introduction to gas discharge plasmas, active plasma species and their inactivating mechanism. Subsequently, significance and aspects of NTP inactivation of biofilm-associated bacteria, especially those of medical importance, including opportunistic pathogens, oral pathogenic bacteria, foodborne pathogens and implant bacteria, are discussed. The remainder of the review discusses majorly about the synergistic effect of NTPs and their activity against biofilm-associated fungi, especially Candida species.

Integrated biomarker profiling of smokers with periodontitis.

In the context of precision medicine, understanding patient-specific variation is an important step in developing targeted and patient-tailored treatment regimens for periodontitis. While several studies have successfully demonstrated the usefulness of molecular expression profiling in conjunction with single classifier systems in discerning distinct disease groups, the majority of these studies do not provide sufficient insights into potential variations within the disease groups. The goal of this study was to discern biological response profiles of periodontitis and non-periodontitis smoking subjects using an informed panel of biomarkers across multiple scales (salivary, oral microbiome, pathogens and other markers). The investigation uses a novel ensemble classification approach (SVA-SVM) to differentiate disease groups and patient-specific biological variation of systemic inflammatory mediators and IgG antibody to oral commensal and pathogenic bacteria within the groups. Sensitivity of SVA-SVM is shown to be considerably higher than several traditional independent classifier systems. Patient-specific networks generated from SVA-SVM are also shown to reveal crosstalk between biomarkers in discerning the disease groups. High-confidence classifiers in these network abstractions comprised of host responses to microbial infection elucidated their critical role in discerning the disease groups. Host adaptive immune responses to the oral colonization/infection contribute significantly to creating the profiles specific for periodontitis patients with potential to assist in defining patient-specific risk profiles and tailored interventions.

Synthesis of Bimetallic Nanoparticles (Au–Ag Alloy) Using Commelina nudiflora L. Plant Extract and Study its on Oral Pathogenic Bacteria

In present study, biosynthesis of Au–Ag alloy nanoparticles (NPs) using Commelina nudiflora aqueous extract as a stabilizing and reducing agent is reported. The crystalline nature, size, shape and composition of synthesized Au–Ag alloy NPs were characterized by UV–Vis spectrophotometer, field emission scanning electron spectroscopy, energy dispersive X-ray spectroscopy, transmission electron microscope, X-ray diffraction and fourier transform-infrared spectroscopy (FT-IR). The synthesized Au–Ag alloy NPs exhibited different ranges of sizes between 20 and 80 nm with different morphology such as spherical, rod and triangular. FT-IR spectral data revealed that the plant extract contains amine, alcohol, phenol and alkane molecules which are critically involved in the formation of Au–Ag alloy NPs. Finally, the biosynthesized Au–Ag alloys NPs exhibited a strong minimum inhibitory, minimum bactericidal activity against selected oral pathogenic bacteria. The present study gives an important suggestion on plant extract mediated synthesis bimetallic NPs (Au–Ag alloy) emphasis on oral pathogenic bacteria activities.

Antimicrobial activity of ethylene-vinyl acetate containing bioactive filler against oral bacteria.

We developed an ethylene vinyl acetate (EVA) containing surface pre-reacted glass-ionomer (S-PRG) filler, as a new mouthguard material for preventing intraoral bacterial infection. We examined its physical properties, antimicrobial activity against a major cariogenic bacterium Streptococcus mutans and a periodontopathogen Porphyromonas gingivalis, and its cytotoxicity toward human gingival epithelial cells. S-PRG filler was added to EVA copolymer at 5, 10, 20, or 40 wt% and was processed into disc-shaped test specimens. Only minor differences between the Shore hardness and rebound resilience properties of EVA materials with and without the S-PRG filler were observed. The specimens with S-PRG filler showed bacteriostatic activity toward S. mutans and P. gingivalis and inhibited S. mutans biofilm formation. No cytotoxicity against the gingival epithelial cells was observed. Our findings show that EVA containing S-PRG filler has antimicrobial activity toward pathogenic oral bacteria and may be an effective material for maintaining the oral health of athletes.

Antimicrobial Activity of a Cationic Guanidine Compound against Two Pathogenic Oral Bacteria.

This study evaluated the potential antimicrobial properties of a polyguanidine (CatDex) on two oral bacteria. Chlorhexidine gluconate 1340 μmoL L−1 (CHX 0.12%) was used as control. Streptococcus mutans (S. mutans) and Porphyromonas gingivalis (P. gingivalis) were grown in BHI media. Bacterial sensitivity and antimicrobial activity were determined by the minimum inhibitory concentration (MIC) and Kirby-Bauer methods. To study side effects, that is, toxicity, dental pulp stem cells (DPSCs) were used. Fluorometric cytotoxicity and confocal microscopy assays were used in order to test cell viability. CatDex inhibited growth of S. mutans at all concentrations and growth of P. gingivalis at all concentrations except 25 μmoL L−1. The MIC of CatDex was 50 μmoL L−1 for both S. mutans and P. gingivalis. The inhibition of bacteria exposed for 8 h at 50 μmoL L−1 of CatDex exhibited increased antimicrobial activity over time, with 91% inhibition in both bacteria. The antimicrobial activities of CatDex and CHX were similar when tested on two common bacteria. CatDex was significantly less toxic to DPSCs. CatDex toxicity depended on time and not on concentration. With regard to clinical relevance, CatDex may have potential as a novel antimicrobial agent. Further studies are in progress.

In vitro Antimicrobial activity of Antidesma bunius extracts on oral pathogenic bacteria

In vitro Antimicrobial activity of Antidesma bunius extracts on oral pathogenic bacteria

Effects of Caesalpinia sappan on pathogenic bacteria causing dental caries and gingivitis.

The present study explores antimicrobial activities of Caesalpinia sappan extracts against three strains of oral pathogenic bacteria; Streptococcus mutans DMST9567 (Smu9), Streptococcus mutans DMST41283 (Smu4), and Streptococcus intermedius DMST42700 (Si). Ethanol crude extract of C. sappan (Cs-EtOH) was firstly compared to that of other medicinal plants using disc diffusion method. Cs-EtOH showed significantly higher effective inhibition against all tested strains than other extracts and 0.12% chlorhexidine with the inhibition zone of 17.5 ± 0.5, 18.5 ± 0.0, and 17.0 ± 0.0 mm against Smu9, Smu4, and Si, respectively. Three fractionated extracts of C. sappan using hexane, ethyl acetate, and ethanol, respectively, were further investigated. The fractionated extract from ethanol (F-EtOH) presented the strongest activities with the minimum bactericidal concentration (MBC) of 125-250 µg/mL. Killing kinetics of F-EtOH was depended on the bacterial species and the concentration of F-EtOH. Two-fold MBC of F-EtOH could kill all tested strains within 12 h whereas its 4-fold MBC showed killing effect against Si within 6 h. Separation of F-EtOH by column chromatography using chloroform/methanol mixture as an eluent yielded 11 fractions (F1-F11). The fingerprints of these fractions by high-performance liquid chromatography at 280 nm revealed that F-EtOH consisted of at least 5 compounds. F6 possessed the significantly highest antimicrobial activity among 11 fractions, however less than F-EtOH. It is considered that F-EtOH is the promising extract of C. sappan for inhibiting oral pathogenic bacteria and appropriate as natural antiseptic for further develop of oral hygiene products.

Elevated salivary IgA, decreased anxiety, and an altered oral microbiota are associated with active participation on an undergraduate athletic team

BackgroundPrevious reports indicate that regular, but not excessive, exercise can moderate the response to anxiety and alter the immune response, therefore we hypothesized that college student athletes who were actively participating on an NCAA Division III athletics team (“in-season”) would have lower levels of anxiety and higher salivary IgA levels than similar college athletes who were in their “off-season”. NCAA Division III athletes participate in athletics at a level of intensity that is more moderate compared to other NCAA divisions. Alterations in the microbiome have been associated with alterations in psychosocial well-being and with exercise. Therefore, we also proposed that the oral microbiota would be different in “in-season” versus “off-season” athletes. MethodIn this pilot study, nineteen female students participating on a NCAA Division III athletic team (hockey=“in-season”; soccer=“off-season”) were compared for level of fitness (modified Balke test of VO2 max), salivary IgA levels by immunoassay, anxiety (using a GAD-7 survey), salivary cortisol levels by immunoassay, and numbers of culturable bacteria by growth of CFU/ml on blood agar, mitis salivarius agar and Staphylococcus 110 agar. ResultsThe proportion of subjects reporting “severe anxiety” on an anxiety scale (GAD-7) were significantly greater in the “off-season” group compared to the “in-season” group (p=0.047, Chi-squared test). “In-season” athletes had significantly higher salivary IgA/total protein levels than “off-season” athletes (one-sided Student's t-test; p=0.03). Cortisol levels were not significantly different in the two groups. The total culturable bacteria counts were higher among “in-season” athletes (p=0.0455, Wilcoxon Rank Sum test), as measured by CFUs on blood agar plates, an estimate of total culturable bacteria, including pathogenic and non-pathogenic bacteria. In contrast, there was a decrease in the growth of bacteria from the oral cavity of the “in-season” athletes, when the growth of bacteria on mitis salivarius agar (primarily oral streptococcus) was measured (p=0.0006, Wilcoxon Rank Sum test). There was a negative correlation (Spearman Rank correlation coefficient=−0.651, p=0.0018 one-sided) between high IgA levels and the growth of bacteria on mitis salivarius agar in the combined group of “in-season” and “off-season” athletes, suggesting a protective response of high IgA levels to the typical oral pathogenic bacteria. Anxiety levels (GAD-7) in the “in-season” group were positively correlated with growth of oral bacteria on blood agar (Spearman Rank correlation coefficient of 0.622 for “in-season”, p value=0.033 one-sided) and mitis salivarius agar (Spearman Rank correlation coefficient=0.671 for “in-season, p value=0.021 one-sided), and negatively correlated in “off-season” athletes on blood agar (−0.689 for “off-season”, p value=0.028 one-sided), supporting the hypothesis that the microbiota are distinct in “in-season” and “off-season” athletes and may be associated with anxiety levels. ConclusionThese findings are supportive of the hypothesis that participation in college level athletics has a positive effect on student-athlete health, specifically enhanced protective oral immunity, reduced anxiety, and alterations in oral microbial populations.

죽엽(솜대)의 항산화 성분 및 구강세균에 대한 항균 효과

본 연구에서는 죽엽(솜대)의 항산화 성분을 조사하고 구강질환 세균에 대한 죽엽 추출물의 항균 활성을 검토하였다. 죽엽의 일반성분은 탄수화물 76.26%, 조회분 10.61%, 조단백질 5.10%, 수분 6.30%, 조지방 1.73%였고, 비타민 A 및 E의 함량에 비하여 비타민 C 함량은 월등히 높게 나타났다. 유기산 중 citric acid 함량이 가장 많이 함유되어 있었고 다음으로 succinic acid, malic acid, acetic acid, formic acid 순으로 검출되었다. 총 폴리페놀 및 플라보노이드 함량은 각각 21.66 mg/g, 42.78 mg/g으로 나타났다. Streptococcus mutans에 대해 죽엽 추출물 0.04% 이상에서, Streptococcus sobrinus에 대해서는 0.16% 이상에서, Porphyromonas gingivalis와 Prevotella intermedia에 대해서는 0.02% 이상에서 강한 항균 활성이 인정되었다. S.mutans, S. sobrinus, P. gingivalis, P. intermedia는 죽엽추출물 0.32% 농도에서 각각 60시간까지 억제됨을 관찰할 수 있었다. 따라서 본 연구 결과는 죽엽 에탄올 추출물이 구강질환을 유발하는 세균에 대하여 우수한 항균작용을 나타내고 있으며, 따라서 죽엽이 구강질환 예방에 긍정적인 효과가 있을 것으로 생각한다.

Physicochemical fabrication of antibacterial calcium phosphate submicrospheres with dispersed silver nanoparticles via coprecipitation and photoreduction under laser irradiation.

Nano- and microsized spheres of calcium phosphate (CaP) containing silver nanoparticles have great potential in dental applications. Conventional fabrication processes were time-consuming or weak regarding the size/shape control of the spheres. In this study, we achieved a simple (one-pot), rapid (20-min irradiation), and surfactant-free fabrication of CaP submicrospheres containing silver nanoparticles by pulsed laser irradiation to a mixture of calcium, phosphate, and silver ion solutions. The resulting CaP submicrospheres contained metallic silver nanoparticles dispersed throughout in a sequence of reactions: CaP and silver coprecipitation, laser-induced melting and spheroidization of the coprecipitates, and photoreduction of silver ions. These submicrospheres showed antibacterial activity against oral bacteria and acid-neutralizing property in the bacterial suspension, and hence are worth considering for dental applications.

Activation of the TREM-1 pathway in human monocytes by periodontal pathogens and oral commensal bacteria.

Periodontitis is a highly prevalent disease caused in part by an aberrant host response to the oral multi-species biofilm. A balance between the oral bacteria and host immunity is essential for oral health. Imbalances in the oral microbiome lead to an uncontrolled host inflammatory response and subsequent periodontal disease (i.e. gingivitis and periodontitis). TREM-1 is a signaling receptor present on myeloid cells capable of acting synergistically with other pattern recognition receptors leading to amplification of inflammatory responses. The aim of this study was to investigate the activation of the TREM-1 pathway in the human monocyte-like cell line THP-1 exposed to both oral pathogens and commensals. The relative expression of the genes encoding TREM-1 and its adapter protein DAP12 were determined by quantitative real-time polymerase chain reaction. The surface expression of TREM-1 was determined by flow cytometry. Soluble TREM-1 and cytokines were measured by enzyme-linked immunosorbent assay. The results demonstrate that both commensal and pathogenic oral bacteria activate the TREM-1 pathway, resulting in a proinflammatory TREM-1 activity-dependent increase in proinflammatory cytokine production.

Viable Compositional Analysis of an Eleven Species Oral Polymicrobial Biofilm.

Purpose: Polymicrobial biofilms are abundant in clinical disease, particularly within the oral cavity. Creating complex biofilm models that recapitulate the polymicrobiality of oral disease are important in the development of new chemotherapeutic agents. In order to do this accurately we require the ability to undertake compositional analysis, in addition to determine individual cell viability, which is difficult using conventional microbiology. The aim of this study was to develop a defined multispecies denture biofilm model in vitro, and to assess viable compositional analysis following defined oral hygiene regimens.Methods: An in vitro multispecies denture biofilm containing various oral commensal and pathogenic bacteria and yeast was created on poly (methyl methacrylate) (PMMA). Denture hygiene regimens tested against the biofilm model included brushing only, denture cleansing only and combinational brushing and denture cleansing. Biofilm composition and viability were assessed by culture (CFU) and molecular (qPCR) methodologies. Scanning electron microscopy and confocal laser scanning microscopy were also employed to visualize changes in denture biofilms following treatment.Results: Combinational treatment of brushing and denture cleansing had the greatest impact on multispecies denture biofilms, reducing the number of live cells by more than 2 logs, and altering the overall composition in favor of streptococci. This was even more evident during the sequential testing, whereby daily sequential treatment reduced the total and live number of bacteria and yeast more than those treated intermittently. Bacteria and yeast remaining following treatment tended to aggregate in the pores of the PMMA, proving more difficult to fully eradicate the biofilm.Conclusions: Overall, we are the first to develop a method to enable viable compositional analysis of an 11 species denture biofilm following chemotherapeutic challenge. We were able to demonstrate viable cell reduction and changes in population dynamics following evaluation of various denture cleansing regimens. Specifically, it was demonstrated that daily combinational treatment of brushing and cleansing proved to be the most advantageous denture hygiene regimen, however, residual organisms still remained within the pores of PMMA surface, which could act as a reservoir for further biofilm regrowth. We have identified an industry need for denture cleansing agents with the capacity to penetrate these pores and disaggregate these complex biofilm consortia.

Possible Link Between Chronic Periodontal Disease and Central

Systemic infection and/or inflammation has been related with an increased risk of brain abscesses, cerebrovascular disease, cognitive impairment and other pathological states of the brain. Therefore, it is plausible, that a chronic infection and inflammation disease, such as periodontitis, may affect the central nervous system (CNS). Chronic periodontal disease is a condition that causes breakdown of the supporting tissues of the teeth, alveolar bone and soft tissues. Chronic periodontitis is a multifactorial disease caused by dental plaque composed of pathogenic bacteria that triggers the immune response in susceptible hosts. Oral pathogenic bacteria is a source of chronic infection that can induce local and peripheral production of pro-inflammatory cytokines such as IL-1s, IL-6 and TNF- , inflammatory mediators, as well as bacterial products such as lipopolysaccaride endotoxin. Viruses, such as herpes and Epstein-Barr, can also be found in periodontal pockets. It is well established that oral pathogenic microorganisms may cause systemic infection by transient or persistent bacteremia, disseminating within the body, and infiltrate distal sites and organs. It has been proposed that in vulnerable populations and under certain circumstances, bacterial and viral infections may enter the brain from the bloodstream. Once in the brain, infectious pathogens and inflammatory products may compromise vascular integrity. Thus, the potential role of the pathogenesis of chronic periodontitis in the development and progression of cerebral infection and inflammation can have a link. There is no direct evidence that determines whether oral diseases have a causal association with CNS pathologies, nonetheless there are several reports that have found oral periodontal pathogens lodged in the brain. Both inflammatory states may just share a casual connection with common risk factors and complex multifactorial etiologies. However, the possibility that pathogenic oral microorganisms disseminate to the bloodstream and reach the brain, initiating or exacerbating existing cerebral lesions, cannot be disregarded. In addition, not only periodontal pathogens may be involved in invading the brain, but also, the pro-inflammatory factors induced systemically by periodontitis, may play a role in CNS pathologies. This oral systemic link will be discussed in this paper.

Effect of roselle calyx extract on invitro viability and biofilm formation ability of oral pathogenic bacteria.

To investigate the effect of the roselle calyx extract (RCE) (Hibiscus sabdariffa L.) on the invitro viability and biofilm formation ability of oral pathogenic bacteria. RCE was prepared by soaking roselle calyx powder with ethyl alcohol for 24h at room temperature. After centrifugation, the extract was lyophilized. Then, the extract was dissolved in phosphate-buffered saline, the pH was adjusted, and the extract was aseptically filtered. We used Streptococcus mutans, Streptococcus sanguinis, Lactobacillus casei, Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis and Prevotella intermedia in this study. The antibacterial activity of the RCE was determined by treating the cells of these bacteria with the extract for 10 or 20min at room temperature. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration was determined using the microdilution method, and the effect of the RCE on the ability to form biofilm was determined using a polystyrene micro plate assay. In addition, we used the WST-1 assay to determine the cytotoxicity of the RCE on HGF, Ca9-22 and KB cells. The RCE had antibacterial activity against oral bacteria used in this study. In particular, most significant antibacterial activity was observed against Fusobacterium nucleatum, Prevotella intermedia and Porphyromonas gingivalis. The MIC and minimum bactericidal concentration were 7.2mg/mL-28.8mg/mL and 14.4 to >57.6mg/mL. The RCE had an inhibitory effect on biofilm formation at the MIC and sub-MIC levels. In addition, the RCE had low cytotoxic effects on HGF, Ca9-22 and KB cells. Thus, our results indicate that the RCE may be used for preventing oral diseases.

Dental Bacterial DNA are Present in the Amniotic Cavity of Healthy Pregnant Women at Term

Aims: To determine if dental bacterial DNA are present in the amniotic cavity of healthy pregnant women undergoing an elective caesarean section at term utilising culture independent techniques. Methods: Pregnant Australian women undergoing an elective caesarean section were recruited. Women completed questionnaires addressing demographics, past and current pregnancies and medical history. One high vaginal swab and three amniotic cavity swabs (amniotic fluid, newborn axilla and placental) were collected under sterile conditions. Samples were analysed using culture-independent techniques to detect the presence of predefined pathogenic bacterial taxa of the oral microbiome. Taxa isolated from the amniotic cavity swabs were compared to those isolated from the vaginal swab. Results: DNA from taxa isolated from the amniotic cavity but not vagina included A. xylosoxidans, A. tumefaciens, B. subtilis, Bartonella sp, Bergeyella sp, C. concisus, C. curvus, C. durum, D. microaerophilus, G. haemolysans, G. morbillorum, G. adiacens, G. elegans, K. pneumoniae, L. casei, L. paracasei, L. fermentum, P. aeruginosa, P. fluorescens, P. pseudoalcaligenes, P. stutzeri, R. microluginosa, S. maltophilia, S. pneumoniae, S. salivarius, S. sanguinis, V. dispar, V. parvula and Xanthomonas sp. Conclusion: The DNA of many pathogenic oral bacteria can be identified in the amniotic cavity of healthy pregnant women at term when utilising culture-independent techniques. Given DNA is not always present in the vagina, the study findings fulfill one criterion necessary for oral haematogenous spread to the amniotic cavity.

The Role of Cardamom Oil in Oral Health: A Short Review

Cardamom is a seed pod, known since antiquity for its culinary and medicinal properties. The spice is native to evergreen rain forest of southern India and now grown in only few tropical countries. Cardamom has also been found to regulate inflammatory and immune activities and may be useful for cancer prevention. Cardamom extracts are effective against oral pathogenic bacteria like Streptococcus mutans and Candida albicans. Most people use cardamom as a spice and are largely unaware of its numerous health benefits. This article briefs the various health benefits of cardamom.

Capping Agent-Dependent Toxicity and Antimicrobial Activity of Silver Nanoparticles: An In Vitro Study. Concerns about Potential Application in Dental Practice.

Objectives: In dentistry, silver nanoparticles (AgNPs) have drawn particular attention because of their wide antimicrobial activity spectrum. However, controversial information on AgNPs toxicity limited their use in oral infections. Therefore, the aim of the present study was to evaluate the antibacterial activities against a panel of oral pathogenic bacteria and bacterial biofilms together with potential cytotoxic effects on human gingival fibroblasts of 10 nm AgNPs: non-functionalized - uncapped (AgNPs-UC) as well as surface-functionalized with capping agent: lipoic acid (AgNPs-LA), polyethylene glycol (AgNPs-PEG) or tannic acid (AgNPs-TA) using silver nitrate (AgNO3) as control.Methods: The interaction of AgNPs with human gingival fibroblast cells (HGF-1) was evaluated using the mitochondrial metabolic potential assay (MTT). Antimicrobial activity of AgNPs was tested against anaerobic Gram-positive and Gram-negative bacteria isolated from patients with oral cavity and respiratory tract infections, and selected aerobic Staphylococci strains. Minimal inhibitory concentration (MIC) values were determined by the agar dilution method for anaerobic bacteria or broth microdilution method for reference Staphylococci strains and Streptococcus mutans. These strains were also used for antibiofilm activity of AgNPs.Results: The highest antimicrobial activities at nontoxic concentrations were observed for the uncapped AgNPs and the AgNPs capped with LA. It was found that AgNPs-LA and AgNPs-PEG demonstrated lower cytotoxicity as compared with the AgNPs-TA or AgNPs-UC in the gingival fibroblast model. All of the tested nanoparticles proved less toxic and demonstrated wider spectrum of antimicrobial activities than AgNO3 solution. Additionally, AgNPs-LA eradicated Staphylococcus epidermidis and Streptococcus mutans 1-day biofilm at concentration nontoxic to oral cells.Conclusions: Our results proved that a capping agent had significant influence on the antibacterial, antibiofilm activity and cytotoxicity of AgNPs.Clinical significance: This study highlighted potential usefulness of AgNPs against oral anaerobic Gram-positive and Gram-negative bacterial infections and aerobic Staphylococci strains provided that pharmacological activity and risk assessment are carefully performed.

The nanotipped hairs of gecko skin and biotemplated replicas impair and/or kill pathogenic bacteria with high efficiency.

We show that gecko microspinules (hairs) and their equivalent replicas, bearing nanoscale tips, can kill or impair surface associating oral pathogenic bacteria with high efficiency even after 7 days of repeated attacks. Scanning Electron Microscopy suggests that there is more than one mechanism contributing to cell death which appears to be related to the scaling of the bacteria type with the hair arrays and accessibility to the underlying nano-topography of the hierarchical surfaces.