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Introduction. An important role in the appearance of acute or chronic infections is played by bacterial biofilms that contain several bacterial species and that develop preferentially on inert surfaces, dead tissues and medical devices. Purpose. In this material we tried to make an interesting study, regarding the adhesion capacity of microbial biofilms characteristic of the oral cavity of human subjects on the surface of materials used for industrial scale manufacturing of dental implants: titanium and zirconium dioxide (Zirconia). Material and methods. For this study were used plates of Ti4 and zirconia, on which adhesion of different bacterial strains belonging to the species Enterobacter cloacae, Klebsiella oxytoca and Klebsiella pneumonia were tested. Results and discussions. A rather high microbial load was observed on both types of materials for all types of bacterial strains studied. For certain types of strains, a lower colonization was noted in the case of zirconium dioxide compared to Ti4 surfaces. Conclusions. Although Zirconia has been reported to have a lower susceptibility to bacterial adhesion, our study contradicts this aspect specified in the literature. Both titanium and zirconium dioxide are promptly colonized by existing bacteria on the teeth left in the oral cavity

Aim: Comparing the bacterial adherence and count on denture bases and underlying mucosa when using chrome-cobalt Co-Cr (Metal), Acetal and Polyether ether keton (PEEK) as denture base materials. Materials and Methods: 20 patients with mandibular Kennedy class III Mod. 1, opposing maxillary fully dentulous ridge were selected. Patients were divided into two groups 10 each. Group I: In a split mouth, patients received removable partial denture with chrome cobalt (Metal) denture base on one side and Acetal denture base on the other side. Group II: In a split mouth patients received chrome cobalt (Metal) denture base on one side and PEEK denture base on the other side. Swabs were taken from the fitting surface of dentures and the mucosa underlying the denture at 1 week, 2 weeks and 3 weeks after insertion. Incubation on blood agar for 24 hours at 37 degrees was done. Results: On the denture base: Acetal showed 6.93±0.08, Metal 6.48±0.15, and Peek 6.85±0.17. On the mucosa: Acetal showed 6.52±0.13, Metal 6.51±0.18, and PEEK 6.55± 0.12. There was insignificant difference between the Acetal and Peek, however metal showed significant difference when compared with other materials. Conclusion: The bacterial count was low on the mucosal surface for the three materials. For the fitting surface both PEEK and acetal resin showed higher count compared to the metallic denture base through the follow up period.

Human nutrition has changed dramatically over the past few decades. The food industry now offers a huge variety of attractive foods that are high in sugars and acids, and the average human consumption of these soft drinks, snacks and convenience foods has skyrocketed. It has been established that nutrition significantly affects dental health. For example, excessive consumption of sugar and sugar-containing foods significantly increases the development of tooth decay. On the other hand, it has been proven that the mechanical properties of the hardness and elastic modulus of enamel and dentin are a predictor of tissue erosion and cariogenic changes in the structure of teeth and can be considered as diagnostic indicators. In this regard, it seems interesting and timely to review the literature data on the study of the effect of sugar and sweet foods on the hardness of tooth enamel.

The search for new methods of treatment of inflammatory periodontal diseases in patients with removable prostheses is an urgent issue for dentists. Currently, positive results in the treatment of gingivitis and periodontitis are achieved using photodynamic therapy, which is based on the destruction of photosensitized microorganisms under the influence of low-intensity laser radiation in a short period of time. This article presents the results of a study of the effectiveness of the choice of structural materials for relocation of removable prostheses in patients with inflammatory diseases of the oral cavity in combination with photodynamic therapy.

Summary Despite the advancements in material science and surgical techniques, the incidence of implant-associated infections (IAIs) has increased significantly. IAIs are mainly caused by microbial adhesion and biofilm formation on implant surfaces. In this study, we aimed to evaluate and critically discuss the antimicrobial efficacy of chitosan-based coatings to prevent the occurrence of IAIs. For this purpose, a PRISMA-oriented systematic review was conducted based on predefined criteria and forty studies were selected for qualitative analysis. Results indicated that chitosan (CS) association with enzymes and antimicrobial peptides improves its antimicrobial activity and extends its use in a broad range of physiological conditions. Likewise, CS association with polymers resulted in enhanced antimicrobial and anti-adhesive coatings with desirable properties, such as biocompatibility and durability, for implantable medical devices (IMDs). These findings can assist researchers in the design of new CS coatings for application in IMDs., Graphical abstract, Microbiofilms; Materials science

Three cases are presented of anophthalmic patients with exposed orbital implants. Although only one patient showed evident clinical signs of infection, all three implants were studied to determine the presence of microorganisms adhered to their surface using a scanning electron microscopy (SEM) and microbiological culture. The SEM allowed the visualisation of microorganisms adhered to the three implants, although only one of them showed growth in the microbiological cultures. In addition, the SEM technique used in case No. 3 achieved a better orientation and appreciation of the microorganisms with respect to the images of cases No. 1 and 2. These findings support the idea that the surface of exposed orbital implants is colonised by microorganisms, even when they still do not show obvious signs of infection. Therefore, mechanical removal of the exposed surface of the implant is necessary before covering it with grafts or flaps.

Background: Denture base materials are subjected to sorption, a process of absorption and adsorption of liquids depending on the environmental conditions, also their fitting surface is subjected to microbial adhesion due to surface irregularities. Soft silicon liners are usually used with removable appliances to decrease load concentration on the hard and soft tissues. Silicon liners also undergo fluid sorption and microbial adhesion.Aim: This study was carried out to assess the effect of standardizing the oral hygiene conditions on the microbial load difference between conventional acrylic denture bases and silicon soft relining material (Mucopren soft) used to reline mandibular complete dentures in atrophied mandibles. Methods: Conventional complete dentures were constructed for 25 patients with flat atrophic mandibular ridges to be used for two weeks, salivary swabs were collected to evaluate oral flora attached on the fitting surface of the denture base and the buccal vestibule, soft liner was applied for all patients mandibular denture surfaces and the same approach was repeated after two weeks of the liner use. Results: Microbial load was found to be significantly higher in the fitting surfaces of the silicon soft liner, than in the conventional acrylic base fitting surfaces.Conclusion: Even under controlled oral conditions, Mucopren soft silicon liner incorporates greater microbial load than acrylic material thus, subjecting patients to numerous infections.

The purpose of this study was to investigate the effects of instrumentation and irrigation on the initial adherence of Enterococcus faecalis to root canal dentin and to explore initial microbial adhesion to root filling materials.The following specimens were prepared: instrumented and uninstrumented dentin, dentin treated with different irrigation protocols, and root filling materials. The number of E. faecalis cells adhered on dentin was measured. The adhesion force of E. faecalis cells on different materials and the roughness of different surfaces were measured. The contact angle of the surfaces was recorded. The results were analyzed using the t test.Instrumented dentin specimens had a significantly higher amount of E. faecalis adherence than uninstrumented dentin. There were higher numbers of adhering bacteria on the dentin when EDTA was used alone (P.05) compared with other irrigants alone. The use of chlorhexidine (CHX) as the last irrigant for a certain time resulted in a reduced number of adhering bacteria when the specimens were first exposed to sodium hypochlorite (NaOCl) followed by EDTA. EDTA used alone had the highest adhesion force followed by NaOCl alone and CHX alone (P.05). Dentin treated with EDTA alone had the highest roughness and contact angle followed by NaOCl alone and CHX alone (P.05). CHX added as the final irrigant after NaOCl with EDTA irrigation reduced the contact angle (P.05). Larger amounts of adhering bacteria and higher adhesion force were detected on the surface of gutta-percha and sealer than on the dentin surface (P.05).Instrumentation and irrigation alter the initial adherence of E. faecalis to root canal dentin and the surface properties of the dentin as well.

Objective: The aim of the study was to evaluate in vitro the amount of Candida albicans and Lactobacillus acidophilus adhering to the surface of Ornibel, a contraceptive vaginal ring with a new pol...

Introduction: Information regarding the adhesion of bacterial species and plaque accumulation to bracket material is limited. Adequate information is needed in order to offer patients orthodontic treatment without significantly increasing their risk of developing white spots, caries, or gingival inflammation. Aim: To determine the levels of the caries-inducing S. mutans species on metallic, self-ligating and ceramic brackets and to compare the total bacterial counts and counts of species present on these bracket materials. Materials and Methods: By means of an in-vitro study, six commercially available bracket systems {3M Gemini (A), American Ortho (B), Ormco (C), Begg (D), Ceramic (E) and Self-ligating (F)} were compared. The brackets were bonded in the cell well culture plate and the agar plates were prepared. Brain heart infusion medium including bacteria and artificial saliva was introduced to each bracket system containing 10 premolar brackets and were incubated. After 72 hours, the adherent bacteria were then detached by sonication and the Colony-Forming Units (CFU) of Streptococcus mutans were calculated on each bracket and were analysed using Statistical Package for the Social Sciences (SPSS) software version 17.0 for Windows. Results: Between the different bracket types, significant differences were found in terms of biofilm formation. The Begg brackets showed the least bacterial adhesion and the self-ligating brackets showed the highest bacterial adhesion and was statistically significant among all the groups (p0.05). Conclusion: Different orthodontic brackets serve as different loci for biofilm formation showing that the Begg brackets are the most hygienic among all the brackets taken in this study.

Polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), and stainless steel (SS) are commonly used in medicine and food production technologies. During contact with microorganisms on the surface of these materials, a microbial biofilm is formed. The biofilm structure is difficult to remove and promotes the development of pathogenic bacteria. For this reason, the inhibition of biofilm formation in medical and food production environments is very important. For this purpose, five naturally occurring compounds were used for antimicrobial screening tests. The two with the best antimicrobial properties were chosen to inhibit the biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa. After 3 days of exposure, thymol reduced the amount of biofilm of Pseudomonas aeruginosa within the range of 70–77% and 52–75% for Staphylococcus aureus. Carvacrol inhibited the formation of biofilms by up to 74–88% for Pseudomonas aeruginosa and up to 86–100% for Staphylococcus aureus. Those phenols decreased the enzyme activity of the biofilm by up to 40–100%. After 10 days of exposure to thymol, biofilm formation was reduced by 80–100% for Pseudomonas aeruginosa and by about 79–100% for Staphylococcus aureus. Carvacrol reduced the amount of biofilm by up to 91–100% for Pseudomonas aeruginosa and up to 95–100% for Staphylococcus aureus.

Introduction: In two-stage implants, micro-gap between the fixture and the abutment and the superstructure are the potential areas to cause peri-implantitis. The surface roughness and surface energy of the implant abutment materials play an important role in the microbial colonisation on their surface and can help the clinician to choose a better implant abutment material in terms of microbial affinity. Aim: To evaluate the effect of surface characteristics of different implant abutment materials on microbial adhesion. Materials and Methods: The comprehensive analytical experimental study was conducted at KAHER KLE VK Institute of Dental Sciences, Belagavi between Jan 2017- Dec 2017. Forty-five (n=45) identical disc shaped specimens were fabricated using; Zirconia (Group A), Titanium alloy (Group B) and Surgical Grade Stainless Steel (Group C). The surface roughness was assessed for all test groups by Profilometer and Scanning Electron Microscope (SEM). The Surface energy was evaluated for all the test group specimens using Goniometer. Microbial adhesion and assessment were performed using sonicating and vortexing method for all the three groups using three different bacterial strains. The Colony Forming Units for all the specimens were tabulated and subjected to statistical analysis to draw the conclusions from the resultant data.The resultant data was analysed using SPSS software (Version 20). In order to collectively compare the means of the study groups pair-wise comparison of the test group was done using paired t-test with (p

The attachment of bacteria and other microbes to natural and artificial surfaces leads to the development of biofilms, which can further cause nosocomial infections. Thus, an important field of research is the development of new materials capable of preventing the initial adhesion of pathogenic microorganisms. In this work, novel polymer/particle composite materials, based on a polythiourethane (PTU) matrix and either spherical (s-ZnO) or tetrapodal (t-ZnO) shaped ZnO fillers, were developed and characterized with respect to their mechanical, chemical and surface properties. To then evaluate their potential as anti-fouling surfaces, the adhesion of two different pathogenic microorganism species, Staphylococcus aureus and Candida glabrata, was studied using atomic force microscopy (AFM). Our results show that the adhesion of both S. aureus and C. glabrata to PTU and PTU/ZnO is decreased compared to a model surface polydimethylsiloxane (PDMS). It was furthermore found that the amount of both s-ZnO and t-ZnO filler had a direct influence on the adhesion of S. aureus, as increasing amounts of ZnO particles resulted in reduced adhesion of the cells. For both microorganisms, material composites with 5 wt.% of t-ZnO particles showed the greatest potential for anti-fouling with significantly decreased adhesion of cells. Altogether, both pathogens exhibit a reduced capacity to adhere to the newly developed nanomaterials used in this study, thus showing their potential for bio-medical applications.

By restoring decayed, traumatized, or missing tooth tissues, dentists introduce a new substrate into the oral cavity, to which dental biofilm (plaque) can adhere and accumulate. Even though microbial adhesion and biofilm development and maturation on a dental material surface follow some general patterns, these processes also depend on the properties of the material itself. There are specific interactions between dental materials and the overlying biofilms. On the one hand, materials can directly affect biofilms by releasing bioactive compounds, which gives an opportunity for the biofilm control and the prevention of secondary caries and other oral infectious diseases. On the other hand, dental plaque has a potential to modify the restorative material’s surface properties, such as surface roughness and topography, which might boost bacterial accumulation and eventually compromise restoration’s longevity. Resin-based composites, which are the most commonly used restorative materials nowadays, seem to be particularly prone to biofilm-induced degradation, since a well-known cariogenic species, Streptococcus mutans, can produce enzymes with esterase activity, capable of breaking down the polymer matrix of composites. However, the regulatory mechanisms behind the production and activity of such enzymes within a large community of different species in dental plaque remain obscure.

Microbial adhesion is critical for parasitic infection and colonization of host cells. To study the host&ndash, parasite interaction in vitro, we established a flow cytometry-based assay to measure the adherence of Trichomonas vaginalis to epithelial cell line SiHa. SiHa cells and T. vaginalis were detected as clearly separated, quantifiable populations by flow cytometry. We found that T. vaginalis attached to SiHa cells as early as 30 min after infection and the binding remained stable up to several hours, allowing for analysis of drug treatment efficacy. Importantly, NADPH oxidase inhibitor DPI treatment induced the detachment of T. vaginalis from SiHa cells in a dose-dependent manner without affecting host cell viability. Thus, this study may provide an understanding for the potential development of therapies against T. vaginalis and other parasite infections.

Pathogenic bacteria use a variety of cell surface adhesins to promote binding to host tissues and protein-coated biomaterials, as well as cell-cell aggregation. These cellular interactions represent the first essential step that leads to host colonization and infection. Atomic force microscopy (AFM) has greatly contributed to increase our understanding of the specific interactions at play during microbial adhesion, down to the single-molecule level. A key asset of AFM is that adhesive interactions are studied under mechanical force, which is highly relevant as surface-attached pathogens are often exposed to physical stresses in the human body. These studies have identified sophisticated binding mechanisms in adhesins, which represent promising new targets for antiadhesion therapy.

To the moment, there is no ideal substance for home-based denture disinfection. This study assessed in vitro the antimicrobial effect of the hydroalcoholic extract of Eugenia uniflora and the effect on the physical properties of denture polymethylmethacrylate (PMMA). Candida albicans, Staphylococcus aureus, and Klebsiella oxytoca were isolated from samples of saliva collected from denture wearers. The extracts were produced in three concentrations, according to the Brazilian Pharmacopeia. One hundred eighty-eight disc-shaped specimens of thermopolymerizable PMMA were prepared and randomly allocated to five treatment groups: sterile saline solution (0.85%; control); chlorhexidine digluconate (0.2%); and hydroalcoholic extract of E. uniflora (0.2%, 0.8%, and 1.16%). The specimens were disinfected for 8 hours/day for 30 days. Adherence of microorganisms to the surface, PMMA surface roughness, and color stability were assessed. Inferential statistics were performed with one- and two-way ANOVA/Tukey test, and Kruskal Wallis, Mann-Whitney U, and paired t-tests, at α=0.05. The extract of E. uniflora at 0.2% and 1.16% reduced the microbial load of K. oxytoca, while chlorhexidine digluconate significantly reduced microbial load of all microrganisms. Microbial adherence at day 10 was reduced by all experimental substances (p0.05). Nevertheless, all experimental groups produced unacceptable color change at the end of the disinfection protocol (p

AIM: To investigate the resistance to bacterial adhesion of materials used in oculoplastic surgery, particularly materials used in the manufacture of orbital implants. METHODS: Seven organisms of conjunctival flora (two strains of Staphylococcus epidermidis and one strain each of Staphylococcus aureus, Staphylococcus hominis, Corynebacterium amycolatum, Acinetobacter calcoaceticus, and Serratia marcescens) were selected. A lactic acid bacterium (Lactobacillus rhamnosus) was also included as positive control because of its well-known adhesion ability. Eight materials used to make oculoplastic prostheses were selected (glass, steel, polytetrafluoroethylene, polymethylmethacrylate, silicone from orbital implants, commercial silicone, porous polyethylene, and semi-smooth polyethylene). Materials surfaces and biofilms developed by strains were observed by scanning electron microscopy. Kinetics of growth and adhesion of bacterial strains were determined by spectrophotometry. Each strain was incubated in contact with plates of the different materials. After growth, attached bacteria were re-suspended and colony-forming units (CFUs) were counted. The number of CFUs per square millimetre of material was statistically analyzed. RESULTS: A mature biofilm was observed in studied strains except Staphylococcus hominis, which simply produced a microcolony. Materials showed a smooth surface on the microbial scale, although steel exhibited 1.0-μm-diameter grooves. Most organisms showed significant differences in adhesion according to the material. There were also significant differences in the total number of CFUs per square millimetre from each material (P=0.044). CFU counts were significantly higher in porous polyethylene than in silicone from orbital implants (P=0.038). CONCLUSION: Silicone orbital implants can resist microbial colonization better than porous polyethylene implants.

The aim of the research is the choice of the optimal material for temporary unremovable dentures supported by the isoelastic implants. The objectives of the research are to study the stress-strain state of structures consisting of milled temporary dentures on isoelastic implants by finite element method and to make a comparative assessment of microbial adhesion to the materials for long-term temporary unremovable dentures in vitro. We made the model of temporary bridges from three units: supporting first premolar, second premolar, supporting first molar. We examined different supporting elements’ combinations of crestal implants, basal implants and natural tooth. We compared three temporary bridges’ materials. We used the standard technique for assessing primary adhesion in vitro with ultrasonic action to study the microbiological properties of materials. Analysis of the data shows that the stress distribution in crowns is practically independent of the properties of the studied temporary bridges’ materials. The areas of maximum stress occur in the intraosseous part of implants in all studied cases. The adhesion of microorganisms is less to samples of Russian material Nolatech compared with samples from foreign analogues: Dentokeep PEEK and Temp Basic. Polished Nolatech showes lower rates of microbial adhesion of all studied representatives of microbial flora, than varnished one.

In the present study, we focus on the effect of eDNA on the initial bacterial adhesion, biofilm formation, and the mature biofilms of 17 different Salmonella serovars. We evaluated the roles of eDNA on the initial microbial adhesion, and found that some of Salmonella serotypes formed significantly more biomass in the presence of DNase I, during the early stages of biofilm formation at 28°C for 24 hours, while same strains were not produce biofilm at 37°C. We suggested that the reason for divesity among biofilm production abilities of different serovars may be due to the variability of gene expression levels at different growth temperatures. It was observed that eDNA had a notable negative effect on the initial attachment of these serovars. 45.8% of all pre-established biofilm samples of serovars were eradicated at high concentrations of DNase I (50 μg/mL). Our study highlights the serotype based role of eDNA in Salmonella strains. This report is one of the few that represents the inhibitive effect of eDNA on biofilm formation of Salmonella strains. Also, this is the fisrt evidence that eDNA has either inhibitive or stimulative effects dependind on the serovars.

Polymicrobial infection is the main cause of dental implant failure. Although numerous studies have reported the ability of titanium (Ti) surface modifications to inhibit microbial adhesion and biofilm accumulation, the majority of solutions for the utilization of Ti antibacterial surfaces have been testedin in vitro and animal models, with only a few developed surfaces progressing into clinical research. Motivated by this huge gap, we critically reviewed the scientific literature on the existing antibacterial Ti surfaces to help understand these surfaces' impact on the "puzzle" of undesirable dental implant-related infections. This manuscript comprises three main sections: (i) a narrative review on topics related to oral biofilm formation, bacterial-implant surface interactions, and on how implant-surface modifications can influence microbial accumulation; (ii) a critical evidence-based review to summarize pre-clinical and clinical studies in an attempt to "fit pieces into the puzzle" to unveil the best way to reduce microbial loads and control polymicrobial infection around dental implants showed by the current in vivo evidence; and (iii) discussion and recommendations for future research testing emerging antibacterial implant surfaces, connecting basic science and the requirements for future clinical translation. The findings of the present review suggest no consensus regarding the best available Ti surface to reduce bacterial colonization on dental implants. Smart release or on-demand activation surface coatings are a "new piece of the puzzle", which may be the most effective alternative for reducing microbial colonization on Ti surfaces, and future studies should focus on these technologies.

Novel technologies to prevent biofilm formation on urinary tract devices (UTDs) are continually being developed, with the ultimate purpose of reducing the incidence of urinary infections. Probiotics have been described as having the ability to displace adhering uropathogens and inhibit microbial adhesion to UTD materials. This work aimed to evaluate the effect of pre-established Lactobacillus plantarum biofilms on the adhesion of Escherichia coli to medical-grade silicone. The optimal growth conditions of lactobacilli biofilms on silicone were first assessed in 12-well plates. Then, biofilms of L. plantarum were placed in contact with E. coli suspensions for up to 24 h under quasi-static conditions. Biofilm monitoring was performed by determining the number of culturable cells and by confocal laser scanning microscopy (CLSM). Results showed significant reductions of 76%, 77% and 99% in E. coli culturability after exposure to L. plantarum biofilms for 3, 6 and 12 h, respectively, corroborating the CLSM analysis. The interactions between microbial cell surfaces and the silicone surface with and without L. plantarum biofilms were also characterized using contact angle measurements, where E. coli was shown to be thermodynamically less prone to adhere to L. plantarum biofilms than to silicone. Thus, this study suggests the use of probiotic cells as potential antibiofilm agents for urinary tract applications.

Objective: The purpose of the this study was to evaluate the oral microbial adhesions and quality of life in Maxillectomy patients after rehabilitation with two types of maxillofacial obturators: Thermopress & Cobalt- Chromium obturators.Materials and Methods: Type of study: Randomized clinical trial (RCT) Ten hemi-maxillectomy patients were taken from the out-patient clinic of the national Institute. Patients Grouping: Patients were randomly divided into two equal groups. Group-I: Five patients had received thermopress obturators. Group–II: patients were rehabilitated with cobalt chromium & polymethyl methacrylate obturators. - Microbial adhesions of viable microorganisms in the accumulating biofilm layer on Polymethylmethacrylate (PMMA) & Thermopress obturator bulb surfaces were determined along four weeks period & converted to Colonies Forming Units (CFU) per cm2 unit surface area . -QOL was evaluated according to the Obturator Functioning Scale’ (OFS). questionnaire by direct interviews with the patients at the end of four weeks period.Results: The results of this study revealed that the microbial adhesions showed statistically significant increase in Group-I patients compared to Group-II; On the other hand, the patient’s quality of life in Group-I recorded higher values in the examined domains than Group- II patients.Conclusion: Within the limitations of this study; it may be concluded that: Thermopress material may induce more microbial adhesions than Cobalt chromium &PMMA ones. Thermoplastic obturators may provide maxillectomy patients better esthetics, speech & social interaction than metalic obturators with conventional PMMA.

Escherichia coli has developed sophisticated means to sense, respond, and adapt in stressed environment. It has served as a model organism for studies in molecular genetics and physiology since the 1960s. Stress response genes are induced whenever a cell needs to adapt and survive under unfavorable growth conditions. Two of the possible important genes are rpoS and bolA. The rpoS gene has been known as the alternative sigma () factor, which controls the expression of a large number of genes, which are involved in responses to various stress factors as well as transition to stationary phase from exponential form of growth. Morphogene bolA response to stressed environment leads to round morphology of E. coli cells, but little is known about its involvement in biofilms and its development or maintenance. This study has been undertaken to address the adherence pattern and formation of biofilms by E. coli on stainless steel, polypropylene, and silicone surfaces after 24 h of growth at 37 °C. Scanning electron microscopy was used for direct examination of the cell attachment and biofilm formation on various surfaces and it was found that, in the presence of bolA, E. coli cells were able to attach to the stainless steel and silicone very well. By contrast, polypropylene surface was not found to be attractive for E. coli cells. This indicates that bolA responded and can play a major role in the presence and absence of rpoS in cell attachment., info:eu-repo/semantics/publishedVersion

Background: Maxillofacial prosthetics includes restoration of maxillary defects resulting from resection of palate and nasosinus neoplasms with obturator prostheses which may be colonized by microorganisms and function as a reservoir of infection. Patients with neoplasms commonly also require radiotherapy that can result in changes in saliva quality and quantity and changes in the oral microbial flora. The altered flora, in individuals immunocompromised from cancer therapy, increases their risk of prosthesis-related infections. Objectives: In this review article, we explore microbial biofilms, their main components, mechanisms of microbial adhesion, and stages of biofilm development. We also discuss the different materials that are used for manufacturing maxillary obturators, their characteristic features, and how these can affect microbial adhesion. Furthermore, we shed some light on the factors that affect microbial adhesion to the surface of maxillary obturators including tissue proteins, protein adsorption, and the acquired enamel pellicle. Conclusions: The conclusions drawn from this literature review are that it is imperative to minimize the risk of local and systemic infections in immunocompromised patients with cancer having maxillary defects. It is also important to determine the role of saliva in microbial adhesion to obturator materials as well as develop materials that have a longer life span with surface characteristics that promote less microbial adhesion than current materials.

Better understanding the mechanisms of Leonurus cardiaca L. extract (LCE) activity is necessary to prepare recommendations for the use of LCE-based herbal products for preventive/supportive purposes in case of infective endocarditis (IE) and other staphylococcal invasive infections. The aim of the study was to analyze molecular mechanisms of LCE effect on Staphylococcus aureus and blood platelets in the context of their interactions playing a pivotal role in such disorders. Using atomic force microscopy, we demonstrated that adhesion forces of S. aureus were markedly reduced after exposure to LCE at subinhibitory concentrations. The effect resulted from the impact of LCE on S. aureus cell morphology and the composition of phospholipids and fatty acids in bacterial membranes (assessed by HPLC), which modulated their stabilization, hydrophobicity, and charge. Moreover, using FACS we showed also that LCE significantly reduced GP IIb/IIIa expression on blood platelets, thus the disruption of platelet-fibrinogen interactions seems to explain antiplatelet effect of LCE. The obtained results prove the usefulness of LCE in the prevention of S. aureus adhesion, platelet activation, and vegetations development, however, also pointed out the necessity of excluding the cationic antibiotics from the treatment of S. aureus-associated IE and other invasive diseases, when motherwort herb is used simultaneously as an addition to the daily diet.

To compare the sensitivity of two genotypes of P. aeruginosa to various disinfectant solutions and analyze the attached bacteria on worn cosmetic contact lenses (cosCLs).In this prospective study, healthy volunteers wore etafilcon (brown), nelfilcon (gray), or hilafilcon (black) cosCLs and microbial adhesion analysis was performed. A rub-off test determined pigment dislodgement. Disinfectant sensitivity to Optifree Replenish (Alcon), Optifree Pure Moist (Alcon), Renu Fresh (BauschLomb), and AoSept Plus (Ciba Vision) was tested at various disinfection times and compared between various genotypes and Type III secretion (T3S) system mutants.Of the 1152 cosCLs collected, 364 were culture positive (32%). The highest rate of culture-positive lens was hilafilcon (chi square, P = 0.0001). Hilafilcon also had a significantly greater number of isolates than etafilcon (P 0.0001). Hilafilcon was the only lens to fail the rub-off test. Cytotoxic strains were significant more resistant to Renu Fresh than were invasive strains, even at 100% of recommended disinfection time (P = 0.0005). Of the tested disinfectants, Renu Fresh was significantly less effective in killing both genotypes of P. aeruginosa compared to AoSept Plus at all time points (25%, 50%, 75%, and 100% recommended disinfection time, P = 0.0001, 0.0001, 0.0005, and 0.0005, respectively). When the T3S system was dysfunctional, mutant strains were all susceptible to disinfectants (P = 0.0001 for both invasive and cytotoxic strains).Pseudomonas species is commonly found on cosCLs of asymptomatic individuals. Wearers of cosCLs that dislodge pigments may be predisposed to microbial contamination. Cytotoxic strains are more resistant to disinfectant solutions, especially to Renu Fresh. P. aeruginosa disinfectant resistance requires a functional T3S system.

Made available in DSpace on 2019-10-04T12:36:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-04-03 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The present study investigated the antimicrobial, anti-adhesion and anti-biofilm activity of the modified synthetic molecules nitrochalcone (NC-E05) and pentyl caffeate (C5) against microorganisms which have a high incidence in hospital-acquired infections. The compounds were further tested for their preliminary systemic toxicity in vivo. NC-E05 and C5 showed antimicrobial activity, with minimum inhibitory concentrations (MICs) ranging between 15.62 and 31.25g ml(-1). Treatment with NC-E05 and C5 at 1xMIC and/or 10xMIC significantly reduced mono or mixed-species biofilm formation and viability. At MIC/2, the compounds decreased microbial adhesion to HaCaT keratinocytes from 1 to 3h (p

Highlights • Rapidly growing mycobacteria (RGM) causing infections by biofilm formation. • Semi-quantitative method of biofilm formation was adapted for macrotechnics. • Sulphonamides complexed with metals is a promising anti-adhesion agent. • Sulphonamides complexed with metal is a possible inhibitor of signaling of biofilm formation., Rapidly growing mycobacteria (RGM) are found in non-sterile water and often associated with severe post-surgical infections and affect immunocompromised patients. In addition, RGM can prevent the host's immune response and have the ability to adhere to and form biofilms on biological and synthetic substrates, making pharmacological treatment difficult because conventional antimicrobials are ineffective against biofilms. Thus, there is an urgent need for new antimicrobial compounds that can overcome these problems. In this context, sulfonamides complexed with Au, Cd, Ag, Cu, and Hg have shown excellent activity against various microorganisms. Considering the importance of combating RGM-associated infections, this study aimed to evaluate the activity of sulfonamide metal complexes against RGM biofilm. The sulfonamides were tested individually for their ability to inhibit mycobacterial formation and destroy the preformed biofilm of standard RGM strains, such as Mycobacterium abscessus, M. fortuitum, and M. massiliense. All sulfonamides complexed with metals could reduce, at subinhibitory concentrations, the adhesion and biofilm formation of three RGM species in polystyrene tubes. It is plausible that the anti-biofilm capacity of the compounds is due to the inhibition of c-di-GMP synthesis, which is an important signal for RGM biofilm formation. Hence, the impacts and scientific contribution of this study are based on the discovery of a potential new therapeutic option against RGM-associated biofilm infections. Sulfonamides complexed with metals have proven to be a useful and promising tool to reduce microbial adhesion on inert surfaces, stimulating the improvement of methodologies to insert compounds as new antibacterial and coating agents for medical and hospital materials.

Introduction: This study aims to evaluate the oral hygiene and microbial adhesion on the 3M stainless steel crown (SSC) and Kids crown in primary molars. Materials and Methods: Seven children aged 4-8 years were selected from the Department of Pediatric and Preventive Dentistry. Children included in the study had lower right or left both first and second primary molars that required SSC. The tooth was restored with 3M crown and Kids crown. The swabs were collected before and immediately after the cementation of crowns and after 1 week. Oral hygiene index (OHI) was also evaluated. The swabs were incubated in mitis salivarius bacitracin agar, and the total number of Streptococcus mutans was counted and expressed in colony forming units. Results: There was no statistically significant difference seen in the microbial count and OHI-simplified between the 3M and Kids crown and natural teeth. Conclusion: The microbial adhesion of plaque and S. mutans was seen higher on the Kids crown. However, there was no significant difference between 3M ESPE and Kids crown.

Dental implants and their prosthetic components are prone to bacterial colonization and biofilm formation. The use of materials that provides low microbial adhesion may reduce the prevalence and progression of peri-implant diseases. In view of the oral environment complexity and oral biofilm heterogeneity, microscopy techniques are needed that can enable a biofilm analysis of the surfaces of teeth and dental materials. This article describes a series of protocols implemented for comparing oral biofilm formation on titanium and ceramic materials for prosthetic abutments, as well as the methods involved in oral biofilms analyses at the morphological and cellular levels. The in situ model to evaluate oral biofilm formation on titanium and zirconia materials for dental prosthesis abutments as described in this study provides a satisfactory preservation of the 48 h biofilm, thereby demonstrating methodological adequacy. Multiphoton microscopy allows the analysis of an area representative of the biofilm formed on the test materials. In addition, the use of fluorophores and the processing of the images using multiphoton microscopy allows the analysis of the bacterial viability in a very heterogeneous population of microorganisms. The preparation of biological specimens for electron microscopy promotes the structural preservation of biofilm, images with good resolution, and no artifacts.

Functionalization of AFM probes with biomolecules or microorganisms allows for a better understanding of the interaction mechanisms driving microbial adhesion. Here we describe the most commonly used protocols to graft molecules and bacteria to AFM cantilevers. The bioprobes obtained that way enable to measure forces down to the single-cell and single-molecule levels.

Adhesion of Helicobacter pylori to the gastric mucosa is a prerequisite for the pathogenesis of H. pylori related diseases. In this study, we investigated the ganglioside composition of human stomach as the target for attachment mediated by H. pylori SabA (sialic acid binding adhesin). Acid glycosphingolipids were isolated from human stomach and separated into subfractions, which were characterized by mass spectrometry and by binding of antibodies, bacteria, and Solanum tuberosum lectin. H. pylori SabA binding gangliosides were characterized as Neu5Acα3-neolactohexaosylceramide and Neu5Acα3-neolactooctaosylceramide, while the other acid human stomach glycosphingolipids characterized (sulfatide and the gangliosides GM3, GD3, GM1, Neu5Acα3-neolactotetraosylceramide, GD1a and GD1b) were not recognized by the bacteria. Defining H. pylori binding glycosphingolipids of the human gastric mucosa will be useful to specifically target this microbe-host interaction for therapeutic intervention.

The fate and transport of pathogenic bacteria from wastewater treatment facilities in the Earth's subsurface have attracted extensive concern over recent decades, while the impact of treated-wastewater chemistry on bacterial viability and transport behavior remains unclear. The influence of retention time in effluent from a full-scale municipal wastewater treatment plant on the survival and deposition of Staphylococcus aureus and Escherichia coli strains in sand columns was investigated in this paper. In comparison to the bacteria cultivated in nutrient-rich growth media, retention in treated wastewater significantly reduced the viability of all strains. Bacterial surface properties, e.g., zeta potential, hydrophobicity, and surface charges, varied dramatically in treated wastewater, though no universal trend was found for different strains. Retention in treated wastewater effluent resulted in changes in bacterial deposition in sand columns. Longer retention periods in treated wastewater decreased bacterial deposition rates for the strains evaluated and elevated the transport potential in sand columns. We suggest that the wastewater quality should be taken into account in estimating the fate of pathogenic bacteria discharged from wastewater treatment facilities and the risks they pose in the aquatic environment.

International audience; Hydrothermally converted coralline hydroxyapatite (HAp) particles loaded with medically active substances were used to develop polylactic acid (PLA) thin film composites for slow drug delivery systems. The effects of HAp particles within PLA matrix on the gentamicin (GM) release and release kinetics were studied. The gentamicin release kinetics seemed to follow Power law Korsmeyer Peppas model with mainly diffusional process with a number of different drug transport mechanisms. Statistical analysis shows very significant difference on the release of gentamicin between GM containing PLA (PLAGM) and GM containing HAp microspheres within PLA matrix (PLAHApGM) devices, which PLAHApGM displays lower release rates. The use of HAp particles improved drug stabilization and higher drug encapsulation efficiency of the carrier. HAp is also the source of Ca2+ for the regeneration and repair of diseased bone tissue. The release profiles, exhibited a steady state release rate with significant antimicrobial activity against Staphylococcus aureus (S. aureus) (SH1000) even at high concentration of bacteria. The devices also indicated significant ability to control the growth of bacterial even after four weeks of drug release. Clinical release profiles can be easily tuned from drug-HAp physicochemical interactions and degradation kinetics of polymer matrix. The developed systems could be applied to prevent microbial adhesion to medical implant surfaces and to treat infections mainly caused by S. aureus in surgery.

ICS have the potential to increase infection by upregulating epithelial microbial adhesion molecules http://ow.ly/Um7730haVgb

The oral environment, where dental constructs and devices are used, is host to various different hostile features of the masticatory system. The oral cavity is the first part of digestive canal, with the additional functions of communication both phonetically and through gesture. As part of the digestive canal, the oral cavity places demands on dental biomaterials and restorations, both mechanically and chemically. Dentition also plays a significant role in the articulation of sounds. In the context of humans, dentition as a part of the oral cavity is of importance for social wellbeing. The natural appearance of teeth in terms of color shade, surface texture, and basic shape of the teeth, has important culturally-related meaning for humans. In the modern world, patients are well aware of the possibilities of dental treatments and how they can fulfill the needs of function and appearance. Another critical aspect of dental biomaterials and restorations relates to temporal properties. The ageing of restorations of whatever material changes the physical and other materials’ properties. Adequate mechanical strength, high surface gloss, and good resistance against wear are examples of requirements for dental restorations. Additionally, biological aspects of biofilm adsorption of proteins and microbes contribute to longevity of restorations, adjacent tissues, and treatment outcome. Complexity of the oral environment, in combination with the complex multiphasic dental biomaterials and dental devices in restorative and prosthetic dentistry, challenges the dental profession in its aim for long-lasting treatment outcomes.

WOS: 000415608500003 PubMed ID: 29142640 PURPOSE. Bacterial adhesion on provisional crown materials retained for a long time can influence the duration for which permanent prosthetic restorations can be healthily worn in the oral cavity. The aim of this study was to compare seven different commonly used provisional crown materials with regard to Streptococcus mutans and Candida albicans surface adhesion. MATERIALS AND METHODS. For each group, twenty specimens of the provisional fixed prosthodontic materials TemDent (Schutz), Imident (Imicryl), Tab 2000 (Kerr), Structur Premium (Voco), Systemp (Ivoclar Vivadent), Acrytemp (Zhermack), and Takilon-BBF (Takilon) were prepared (diameter, 10.0 mm; height, 2.0 mm). Surface roughness was assessed by atomic force microscopy. Each group was then divided into 2 subgroups (n=10) according to the microbial suspensions used: S. mutans and C. albicans. The specimens were incubated at 37 degrees C with S. mutans or C. albicans for seven days. Bacterial adherence on surfaces was assessed using the 2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) assay. RESULTS. S. mutans showed maximum adhesion to Structur, followed by Systemp, Acrytemp, Takilon, Tab 2000, Imident, and TemDent (P

Mimics of natural carbohydrates (glycomimetics) and unnatural glycoconjugates are under intense scrutiny for the development of anti-infective therapies alternative or complementary to classical antibiotics. Three current approaches are reviewed in this article: (1) antiadhesive therapies, that focus on disrupting carbohydrate-protein complexes involved in microbial adhesion to host cells; (2) vaccines that use as antigens either polysaccharide fragments from bacterial and viruses surface or bacterial and viral lectins; (3) small molecule glycomimetic inhibitors of bacterial enzymes and antivirals.

One important virulence factor of enterotoxigenic Escherichia coli is their ability to adhere via fimbrial adhesins to specific receptors located on the intestinal mucosa. Here, the potential glycosphingolipid receptors of enterotoxigenic F6-fimbriated E. coli were examined by binding of purified F6 fimbriae, and F6-expressing bacteria, to glycosphingolipids on thin-layer chromatograms. When intestinal mucosal non-acid glycosphingolipids from single pigs were assayed for F6 binding capacity, a selective interaction with two glycosphingolipids was observed. The binding-active glycosphingolipids were isolated and characterized as lactotriaosylceramide (GlcNAc beta 3Gal beta 4Glc beta 1Cer) and lactotetraosylceramide (Gal beta 3GlcNAc beta 3Gal beta 4Glc beta 1Cer). Further binding assays using a panel of reference glycosphingolipids showed a specific interaction between the F6 fimbriae and a number of neolacto core chain (Gal beta 4GlcNAc) glycosphingolipids. In addition, an occasional binding of the F6 fimbriae to sulfatide, galactosylceramide, lactosylceramide with phytosphingosine and/or hydroxy fatty acids, isoglobotriaosylceramide, gangliotriaosylceramide, and gangliotetraosylceramide was obtained. From the results we conclude that lactotriaosylceramide and lactotetraosylceramide are major porcine intestinal receptors for F6-fimbriated E. coli.

Summary Background The development of devices with surfaces that have an effect against microbial adhesion or viability is a promising approach to the prevention of device-related infections. Aim To review the strategies used to design devices with surfaces able to limit microbial adhesion and/or growth. Methods A PubMed search of the published literature. Findings One strategy is to design medical devices with a biocidal agent. Biocides can be incorporated into the materials or coated or covalently bonded, resulting either in release of the biocide or in contact killing without release of the biocide. The use of biocides in medical devices is debated because of the risk of bacterial resistance and potential toxicity. Another strategy is to modify the chemical or physical surface properties of the materials to prevent microbial adhesion, a complex phenomenon that also depends directly on microbial biological structure and the environment. Anti-adhesive chemical surface modifications mostly target the hydrophobicity features of the materials. Topographical modifications are focused on roughness and nanostructures, whose size and spatial organization are controlled. The most effective physical parameters to reduce bacterial adhesion remain to be determined and could depend on shape and other bacterial characteristics. Conclusions A prevention strategy based on reducing microbial attachment rather than on releasing a biocide is promising. Evidence of the clinical efficacy of these surface-modified devices is lacking. Additional studies are needed to determine which physical features have the greatest potential for reducing adhesion and to assess the usefulness of antimicrobial coatings other than antibiotics.

Microbial symbionts of honeybee colony are considered as promising tools to support the honeybee population welfare. The majority of existing honeybee microbiota studies is focused on genetic description of the honeybee-associated microbiome fingerprints. The lack of a deeper knowledge on the bacterial community colonizing the honeybee niche, which may be helpful in encouraging industrial applications of this microbiota, led us to undertake this study. The biodiversity of the cultivable fructophilic lactic acid bacteria (FLAB) isolated from adult honeybee intestine and beebread samples was studied. Phenotypic properties of probiotic interest, such as the adhesive potential using in vitro models and adhesion determinants, were also investigated. Antibiotic resistance profiles as reliable markers to evaluate the impact of long-term and current exposure of honeybees to antibiotics were phenotypically determined on the isolated lactic acid bacteria (LAB). The mannose-specific adhesion and high cell surface hydrophobicity found in the studied FLAB isolates sheds light on the effective adaptation of microbiota to specific ecologic niche. It is the first report of phenotypically detected antibiotic resistance profiles of honeybee endogenous bacteria and the first account of minimum inhibitory concentration (MIC) values for four antibiotics used in beekeeping practice.