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Background: Periodontitis, a chronic inflammatory oral infection is the outcome of disturbances in the homeostasis of the oral biofilm microbiota. A number of studies have found the occurrence of Prevotella species in elevated levels in periodontitis compared to healthy subjects. Even though different aspects of Prevotella as part of oral biofilm have been studied, in vitro biofilms formed by these species have not been characterized systematically. The objective of this study was to characterize biofilms formed by several Prevotella species and further to assess biofilm inhibition and detachment of preformed biofilms.Methods: Biofilms were grown in 24-well plates containing brucella broth in anaerobic conditions for 3 days, and were quantified using crystal violet staining. Images of SYTO 9 Green fluorescent stained biofilms were captured using confocal microscopy. Biofilm inhibition and detachment by proteinase and DNase I was tested. The biochemical characterization included quantification of proteins and DNA in the biofilms and biofilm-supernatants.Results:Prevotella loescheii, Prevotella oralis and Prevotella nigrescens showed highest biofilm formation. P. nigrescens formed significantly higher amounts of biofilms than P. loescheii (P = 0.005) and P. oralis (P = 0.0013). Inhibition of biofilm formation was significant only in the case of P. oralis when treated with proteinase (P = 0.037), whereas with DNase I treatment, the inhibition was not significant (P = 0.531). Overall, proteinase was more effective in biofilm detachment than DNase I. Protein and DNA content were higher in biofilm than the supernatant with the highest amounts found in P. nigrescens biofilm and supernatants. P. oralis biofilms appeared to secrete large amounts of proteins extracellularly into the biofilm-supernatants.Conclusion: Significant differences among Prevotella species to form biofilms may imply their variable abilities to get integrated into oral biofilm communities. Of the species that were able to grow as biofilms, DNase I and proteinase inhibited the biofilm growth or were able to cause biofilm detachment.

Filifactor alocis is a Gram-positive asaccharolytic, obligate anaerobic rod of the Firmicutes phylum, which has recently been implicated in oral infections. Extracellular vesicles (EVs) are crucial conveyors of microbial virulence in bacteria and archaea. Previously, in highly purified EVs from the F. alocis reference strain ATCC 35896 (CCUG 47790), 28 proteins were identified. The present study aimed to use label-free quantification proteomics in order to chart these EV proteins, in the reference strain, and in nine less-well-characterized clinical F. alocis isolates. In total, 25 of the EV proteins were identified and 24 were quantified. Sixteen of those were differentially expressed between the ten strains and the novel FtxA RTX toxin and one lipoprotein were among them. Consistent expression was observed among ribosomal proteins and proteins involved in L-arginine biosynthesis and type IV pilin, demonstrating a degree of EV protein expression preservation among strains. In terms of protein–protein interaction analysis, 21 functional associations were revealed between 19 EV proteins. Interestingly, FtxA did not display predicted interactions with any other EV protein. In conclusion, the present study charted 25 EV proteins in ten F. alocis strains. While most EV proteins were consistently identified among the strains, several of them were also differentially expressed, which justifies that there may be potential variations in the virulence potential among EVs of different F. alocis strains.

Current patterns of preventive antibiotic prescribing are encouraging the spread of antimicrobial resistance. Recently, the Spanish Society of Implants (SEI) developed the first clinical practice guidelines published to date, providing clear guidelines on how to prescribe responsible and informed preventive antibiotic therapy (PAT) based on the available scientific evidence on dental implant treatments (DIs). The present document aims to summarise and disseminate the recommendations established by this expert panel. These were based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Studies were analysed using the Scottish Intercollegiate Guidelines Network (SIGN) checklist templates and ranked according to their level of evidence. They were then assigned a level of recommendation using the Grading of Recommendations, Assessment, Development and Evaluation system (GRADE). Guidelines were established on the type of PAT, antibiotic and dosage of administration in the placement of DIs without anatomical constraints, in bone augmentation with the placement of DIs in one or two stages, placement of immediate DIs, sinus elevations, implant prosthetic phase, as well as recommendations in patients allergic to penicillin. Therefore, the PAT must be adapted to the type of implant procedure to be performed.

The antimicrobial resistance (AMR) phenomenon is an emerging global problem and is induced by overuse and misuse of antibiotics in medical practice. In total, 10% of antibiotic prescriptions are from dentists, usually to manage oro-dental pains and avoid postsurgical complications. Recent research and clinical evaluations highlight new therapeutical approaches with a reduction in dosages and number of antibiotic prescriptions and recommend focusing on an accurate diagnosis and improvement of oral health before dental treatments and in patients’ daily lives. In this article, the most common clinical and operative situations in dental practice, such as endodontics, management of acute alveolar abscesses, extractive oral surgery, parodontology and implantology, are recognized and summarized, suggesting possible guidelines to reduce antibiotic prescription and consumption, maintaining high success rates and low complications rates. Additionally, the categories of patients requiring antibiotic administration for pre-existing conditions are recapitulated. To reduce AMR threat, it is important to establish protocols for treatment with antibiotics, to be used only in specific situations. Recent reviews demonstrate that, in dentistry, it is possible to minimize the use of antibiotics, thoroughly assessing patient’s conditions and type of intervention, thus improving their efficacy and reducing the adverse effects and enhancing the modern concept of personalized medicine.

Filifactor alocis is a Gram-positive asaccharolytic, obligate anaerobic rod of the phylum Firmicutes, and is considered an emerging pathogen in various oral infections, including periodontitis. We here aimed to perform phylogenetic analysis of a genome-sequenced F. alocis type strain (ATCC 35896, CCUG 47790), as well as nine clinical oral strains that we have independently isolated and sequenced, for identification and deeper characterization of novel genomic elements of virulence in this species. We identified that 60% of the strains carried a gene encoding a hitherto unrecognized member of the large repeats-in-toxins (RTX) family, which we have designated as FtxA. The clinical infection origin of the ftxA-positive isolates largely varied. However, according to MLST, a clear monophylogeny was reveled for all ftxA-positive strains, along with a high co-occurrence of lactate dehydrogenase (ldh)-positivity. Cloning and expression of ftxA in E. coli, and purification of soluble FtxA yielded a protein of the predicted molecular size of approximately 250 kDa. Additional functional and proteomics analyses using both the recombinant protein and the ftxA-positive, and -negative isolates may reveal a possible role and mechanism(s) of FtxA in the virulence properties of F.alocis, and whether the gene might be a candidate diagnostic marker for more virulent strains.

Oropharyngeal candidiasis is a common opportunistic mucosal infection of the oral cavity, mainly caused by an overgrowth of Candida albicans. This infection can inhibit nutritional intakes and strongly affect quality of life. To date, standard therapeutic strategies involving the administration of antifungal drugs can bring several side effects, not least the emergence of drug-resistant strains. The purpose of this study is to investigate the effectiveness of Saccharomyces cerevisiae CNCM I-3856 (live or inactivated cells) against oropharyngeal candidiasis. Our results show that administration of S. cerevisiae CNCM I-3856 (live or inactivated cells) in the oral cavity of C57BL/6J mice resulted in a protective effect against oropharyngeal candidiasis. The strongest effect was obtained with live S. cerevisiae CNCM I-3856. This was related to: (1) a decrease in C. albicans load in the oral cavity, esophagus, stomach, and duodenum; (2) an early resolution of inflammatory process in the tongue; (3) a marked reduction in C. albicans virulence factors; and (4) a consistent increase in neutrophil antimicrobial capacity. These findings suggest that S. cerevisiae products are potentially beneficial in the treatment of oropharyngeal candidiasis.

The spread of antibiotic resistance and the challenges associated with antiseptics such as chlorhexidine have necessitated a search for new antibacterial agents against oral bacterial pathogens. As a result of failing traditional approaches, drug repurposing has emerged as a novel paradigm to find new antibacterial agents. In this study, we examined the effects of the FDA-approved anticancer agent toremifene against the oral bacteria Porphyromonas gingivalis and Streptococcus mutans . We found that the drug was able to inhibit the growth of both pathogens, as well as prevent biofilm formation, at concentrations ranging from 12.5 to 25 μM. Moreover, toremifene was shown to eradicate preformed biofilms at concentrations ranging from 25 to 50 μM. In addition, we found that toremifene prevents P. gingivalis and S. mutans biofilm formation on titanium surfaces. A time-kill study indicated that toremifene is bactericidal against S. mutans . Macromolecular synthesis assays revealed that treatment with toremifene does not cause preferential inhibition of DNA, RNA, or protein synthesis pathways, indicating membrane-damaging activity. Biophysical studies using fluorescent probes and fluorescence microscopy further confirmed the membrane-damaging mode of action. Taken together, our results suggest that the anticancer agent toremifene is a suitable candidate for further investigation for the development of new treatment strategies for oral bacterial infections.

Protective athletic mouthguards (PAM) or mouthpieces provide protection for the teeth during contact sports.4,12-14,16,18,19 These results have prompted the American Dental Association to support the use of PAM for all contact sports. Football teams at all levels have been among the most compliant with the association’s recommendations. However, the best practices for sanitization and changing these devices are unknown.2 Many teams allow players to store and replace their PAM as they deem necessary.1,3,5,15 Recent studies of hockey players,8 football players, and medical students6 have shown that PAM harbor a range of pathogenic and opportunistic bacteria, yeasts, and molds.17 Ultrastructural analyses by scanning electron microscopy reveal that the microorganisms can be found both on the surfaces and in the porosities of the polymerized PAM material (Figures 1 and ​and22). Figure 1. Scanning electron microscopy of a typical protective athletic mouthguard. Note the large crevices that allow for deep penetration of microorganisms and produce difficulties in the mechanical removal of the microbes. Original magnification, 1000×. ... Figure 2. Scanning electron microscopy of a protective athletic mouthguard demonstrating large accumulations of a variety of microorganisms forming a complex network (biofilm), as well as areas that appear completely free of any microbes (no biofilm). Original ... In previous studies of PAM, the 2 most frequently isolated gram-positive cocci (Staphylococcus aureus and Staphylococcus epidermidis) were not only prominent skin pathogens but also associated with endocarditis, pericarditis, pneumonia, osteomyelitis, food intoxication, and athletic equipment contamination.6,8 Other species of bacteria and fungi isolated from the football and hockey PAM were associated with myriad diseases, such as meningitis, urinary tract infections, peritonitis, periodontal disease, wound infections, and exercise-induced asthma.9,10 While both football and hockey PAM studies do not represent the total microbial population found on PAM, they are sufficient to warrant genuine concern. Also, the condition of PAM after wear may facilitate disease transmission.6,8-10 The jagged, sharp areas of the posterior regions of typical PAM are in close proximity to the pterygoid plexus of veins and, therefore, the entire circulatory system (Figure 3). A recent study over the course of a season confirmed that football mouthguards increased the number and severity of oral mucosal injuries.9 Previous studies found that some commercially available PAM were contaminated before use.6,8 Figure 3. Typical protective athletic mouthguard after a season of wear. Note the rough, jagged edges capable of creating a microbial portal of entry into the tissues. PAM storage is also an important factor to consider. Rules dictate that the football and hockey PAM be in the players’ mouths during play; a typical location of the PAM between plays is often extraoral (Figure 4). These tendencies facilitate the contamination of the device with a range of environmental microbes. Figure 4. Typical position of the protective athletic mouthguard in between plays (arrow), allowing for substantial environmental contamination. PAM are porous and can become contaminated, emphasizing the need to evaluate the in vivo spectra of microorganisms that may be found within such devices. The following study was performed to address these questions: (1) Do PAM become contaminated by a range of microorganisms with wear? (2) Can the microorganisms found on and in PAM be either eliminated or significantly reduced (103 reduction) using a sanitizing formulation (NitrAdine, MSI Laboratory, Vaduz, Liechtenstein)?

The specific aim of this work was to prepare mucoadhesive patches containing tetracycline hydrochloride and carvacrol in an attempt to develop a novel oral drug delivery system for the treatment of mouth infections. The bilayered patches were prepared using ethyl cellulose as a backing layer and carbopol 934 as a matrix mucoadhesive layer. Patches were prepared with different loading amounts of tetracycline hydrochloride and carvacrol. The antimicrobial activity was assessed for the prepared patches using the disc-diffusion method against the yeast Candida albicans and five bacterial strains, including Pseudomonas aeruginosa, Escherichia coli, Bacillus cereus, Staphylococcus aureus, and Bacillus bronchispti. In this work, we highlighted the possibility of occurrence of a synergistic action between carvacrol and tetracycline. The best formulation was selected based on microbiological tests, drug release, ex-vivo mucoadhesive performance, and swelling index. Physical characteristics of the selected formulations were determined. These included pH, patch thickness, weight uniformity, content uniformity, folding endurance, and patch stability.

Background: Oral microbial flora is increasingly being incriminated in oral infections. There is paucity of information on the importance of aerobic oral flora in diabetes. The purpose of this study was to compare aerobic oral microbial flora in diabetics and non-diabetics and to relate these microbes with oral infections. Materials and Methods: This study involved 154 diabetics and 111 non-diabetics aged 18 years and above. Oral washes were inoculated unto blood agar, chocolate agar, Mac Conkey agar and Sabouraud’s agar and isolates were identified by standard biochemical tests. Oral exam was conducted by a Dentist to assess oral infections and oral health status of participants. Results: Thirteen different genera of aerobic microbes were identified. The most prevalent microbes were Streptococcus sp (99.6 %), Candida albicans (17.0 %), Serratia Spp (7.2 %), other Candida Spp (6.8 %), Coagulase negative Staphylococci (CNS) (6.4 %) and Klebsiella Spp (5.7 %). Candida sp was more prevalent in diabetic patients than non-diabetics. Gram negative aerobic bacteria were significantly isolated from cases of dental caries. Conclusion: The oral microbiological profile of diabetic patients was different from those of non-diabetics and aerobic Gram negative bacteria may play an important role in dental diseases in diabetic patients. Keywords: Oral microbiological profile; oral infections; diabetes; Cameroon Contexte: La flore microbienne orale est de plus en plus incriminee dans les infections buccales. Il existe peu d'informations sur l'importance de la flore buccale aerobie chez les diabetiques. Le but de cette etude etait de comparer la flore microbienne aerobie orale chez les diabetiques et les non diabetiques et de determiner le lien que ces germes ont avec les infections buccales. Materiels et methodes: Cette etude a porte sur 154 diabetiques et 111 non-diabetiques âges de 18 ans et plus. Le liquide de lavage buccal a ete inocule sur des geloses au sang, au chocolat, de Mac Conkey et de Sabouraud respectivement, et les souches bacteriennes ont ete identifiees par des tests biochimiques standards. L’examen oral a ete mene par un dentiste afin d’evaluer les infections buccales et l'etat de sante bucco-dentaire des participants. Resultats: Treize genre differents de microorganismes aerobies ont ete identifies. Les microbes les plus repandus etaient Streptococcus sp (99,6%), Candida albicans (17,0%), Serratia spp (7,2%), les autres especes de Candida (6,8%), les staphylocoques a coagulase negative (SCN) (6,4%) et Klebsiella spp (5,7%). Candida spp etait plus frequent chez les patients diabetiques que chez les non-diabetiques. Les bacteries Gram negatives aerobies ont ete considerablement isolees des cas de caries dentaires. Conclusion: Le profil microbiologique oral des patients diabetiques etait different de ceux des non- diabetiques. Les bacteries Gram negatif aerobies peuvent jouer un role important dans les maladies dentaires chez les patients diabetiques. Mots-cles: Profil microbiologique orale; infections buccales; diabete; Cameroun Article in English.

Cryptobacterium curtum Nakazawa et al. 1999 is the type species of the genus, and is of phylogenetic interest because of its very distant and isolated position within the family Coriobacteriaceae. C. curtum is an asaccharolytic, opportunistic pathogen with a typical occurrence in the oral cavity, involved in dental and oral infections like periodontitis, inflammations and abscesses. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of the actinobacterial family Coriobacteriaceae, and this 1,617,804 bp long single replicon genome with its 1364 protein-coding and 58 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

Oral infections caused by yeast of the genus Candida and particularly Candida albicans (oral candidoses) have been recognised throughout recorded history. However, since the 1980s a clear surge of interest and associated research into these infections have occurred. This has largely been due to an increased incidence of oral candidosis over this period, primarily because of the escalation in HIV-infection and the AIDS epidemic. In addition, changes in medical practice leading to a greater use of invasive clinical procedures and a more widespread use of immunosuppressive therapies have also contributed to the problem. Whilst oral candidosis has previously been considered to be a disease mainly of the elderly and very young, its occurrence throughout the general population is now recognised. Candida are true ‘opportunistic pathogens’ and only instigate oral infection when there is an underlying predisposing condition in the host. Treatment of these infections has continued (and in some regards continues) to be problematic because of the potential toxicity of traditional antifungal agents against host cells. The problem has been compounded by the emergence of Candida species other than C. albicans that have inherent resistance against traditional antifungals. The aim of this review is to give the reader a contemporary overview of oral candidosis, the organisms involved, and the management strategies that are currently employed or could be utilised in the future. Keywords: oral candidosis; Candida(Published: 28 January 2011)Citation: Journal of Oral Microbiology 2011, 3: 5771 - DOI: 10.3402/jom.v3i0.5771

The focus has traditionally been on bacteria and fungi when discussing microbiological aspects of oral disease. Viruses are probably more involved in diseases associated with the oral cavity than has been previously thought. The role of several viruses in ulceration is well known, but viruses of the herpes family may play a role in periodontitis, and papillomaviruses are probably involved in oral cancer. This review offers a brief introduction to virology before discussing the role of the more relevant viruses in oral disease. As to clinical application, it is concluded that the anti-herpes medication may, in some cases, be relevant in treating periodontitis, while papillomavirus vaccine would be expected to decrease the prevalence of oral cancer. Keywords: virology; periodontitis; cancer; herpesvirus; papillomavirus; enterovirus (Published: 12 February 2010) Citation: Journal of Oral Microbiology 2010. 2: 2127 - DOI: 10.3402/jom.v2i0.2127*The Chief Editor Ingar Olsen, has not had any part in the review and decision process for this paper.

Background: Plasma antibody measurements of antibody levels to periodontal pathogens may be used to support diagnosis, disease activity, classification, and prognosis of periodontitis. Objective: The aim of this study was to investigate the long-term stability of plasma antibody levels against Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis . Design: Plasma immunoglobulin G (IgG) antibody levels against the pathogens were analyzed annually during 15 years from 21 voluntary subjects, whose periodontal status was not known at the point of selection. The total number of plasma samples was 315. In connection of the last sampling, the clinical and radiographic periodontal status was examined. Pooled bacterial samples from periodontal pockets, as well as salivary samples were collected for A. actinomycetemcomitans and P. gingivalis detection, and antibody determinations, respectively. According to the clinical status, six subjects had periodontitis, whereas 15 did not. Results: Plasma IgG-class antibody levels to periodontal pathogens remained extremely stable during the 15-year period and no significant (p>0.05) intra-individual variations were observed. Retrospectively, the average plasma IgG antibody levels against A. actinomycetemcomitans and P. gingivalis were 1.6-2.3 (p