scholarly journals Initial Bacterial Adhesion and Biofilm Formation on Aligner Materials

Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 908
Author(s):  
Sibel Tektas ◽  
Thomas Thurnheer ◽  
Theodore Eliades ◽  
Thomas Attin ◽  
Lamprini Karygianni
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Statistical Significance ◽  
Sample Surface ◽  
Human Saliva ◽  
Bacterial Attachment ◽  
Columbia Blood Agar ◽  
Conventional Brackets ◽  
Aerobic And Anaerobic

The present study aims to assess the initial bacterial adhesion and biofilm formation on different aligner materials. A total of four different aligner materials, CA-medium (CAM), copolyester (COP), Duran (DUR), Erkodur (ERK), were tested. Stimulated human saliva was obtained from six healthy volunteers. Salivary bacteria were harvested by centrifugation, and 1 mL of the salivary suspension was injected onto each sample surface for 2 h and 3 days, respectively. The samples were then washed twice with 5 mL 0.9% NaCl solution, and non-adherent bacteria were removed. The adherent microorganisms were dislodged from the sample surfaces after ultrasonication for 4 min in 1 mL 0.9% NaCl on ice. After the incubation of the adherent salivary bacteria under both aerobic and anaerobic conditions on Columbia blood agar plates at 37 °C and 5% CO2 and in anaerobic jars overnight, several dilutions thereof were used for the determination of CFUs. This protocol was applied three times, obtaining an average of nine independent measurements for each material group. Overall, the differences between the tested aligner materials as well as between the materials and controls were not of statistical significance (p > 0.05). Regarding initial bacterial attachment and biofilm formation, the tested aligner materials are comparable to enamel and metal orthodontic brackets and can be therefore considered for clinical use. The four tested aligner materials CAM, COP, DUR, ERK showed no significant differences in initial microbial attachment and biofilm formation of aerobic and anaerobic species compared to enamel and conventional brackets.

scholarly journals Determination of the Shear Force at the Balance between Bacterial Attachment and Detachment in Weak-Adherence Systems, Using a Flow Displacement Chamber

2007 ◽  
Vol 74 (3) ◽  
pp. 916-919 ◽  
Author(s):  
M. Reza Nejadnik ◽  
Henny C. van der Mei ◽  
Henk J. Busscher ◽  
Willem Norde
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Shear Force ◽  
Polymer Brush ◽  
Bacterial Attachment ◽  
Adhesion Forces ◽  
Shear Forces ◽  
Flow Displacement

ABSTRACT We introduce a procedure for determining shear forces at the balance between attachment and detachment of bacteria under flow. This procedure can be applied to derive adhesion forces in weak-adherence systems, such as polymer brush coatings, which are currently at the center of attention for their control of bacterial adhesion and biofilm formation.

Bacterial Adhesion to Oral Tissues: A Model for Infectious Diseases

1989 ◽  
Vol 68 (5) ◽  
pp. 750-760 ◽  
Author(s):  
R.J. Gibbons
Keyword(s):  
Conformational Changes ◽  
Oral Hygiene ◽  
Bacterial Adhesion ◽  
Periodontal Diseases ◽  
Bacterial Colonization ◽  
Human Saliva ◽  
Bacterial Attachment ◽  
Poor Oral Hygiene ◽  
Human Teeth ◽  
Mucosal Surfaces

The majority of bacteria which colonize humans display sharp host and tissue tropisms; consequently, relatively little is known about how they initiate colonization on mucosal surfaces. The mouth has a variety of features which have enabled it to serve as a useful model for the discovery of basic principles of host-parasite interactions occurring in mucosal environments. Early studies demonstrated that indigenous bacteria attach to surfaces of the mouth in a highly selective manner; attachment was often observed to correlate with colonization. These studies led to the recognition that bacterial attachment is an essential step for colonization in environments which contain surfaces exposed to a fluid flow. Bacterial adhesion has subsequently grown into a major area of infectious disease research. Many bacteria have been found to possess proteinaceous components, called "adhesins", on their surfaces which bind in a stereochemically specific manner to complementary molecules, or "receptors", on the tissue surface. Adhesins are often lectins which bind to saccharide receptors, but some adhesins are thought to bind to proteinaceous receptors. Studies of components of human saliva, which adsorb to hydroxyapatite (HA) surfaces similar to those of teeth, and promote the attachment of prominent plaque bacteria, have revealed that the acidic proline-rich proteins (PRPs) promote the attachment of several important bacteria. These include strains of Actinomyces viscosus, Bacteroides gingival is, some strains of Streptococcus mutans, and others. The salivary PRP's are a unique family of molecules. However, segments of PRPs are structurally related to collagen. This may be significant, since B. gingivalis and certain cariogenic streptococci bind to collagenous substrata, and such interactions may facilitate their invasion into gingival tissues, or into dentin or cementum, respectively. Another unexpected observation was that although A. viscosus and other bacteria bind avidly to PRPs adsorbed onto apatitic surfaces, they do not interact with PRPs in solution. PRP molecules evidently undergo a conformational change when they adsorb to HA, and adhesins of A. viscosus recognize cryptic segments which are only exposed in adsorbed molecules. This provides the bacteria with a mechanism for efficiently attaching to teeth while suspended in saliva. It also offers a molecular explanation for their sharp tropisms for human teeth. It has proven convenient to refer to such hidden receptors for bacterial adhesins as "cryptitopes" (from cryptic, meaning hidden, and topo, meaning place). The generation of cryptitopes due to conformational changes or because of enzymatic modifications appears to be involved in the colonization of several bacteria on mucosal surfaces. In addition, there is evidence which suggests that elevated levels of neuraminidases and proteases associated with poor oral hygiene and gingivitis may also generate cryptitopes which promote colonization of certain Gram-negative bacteria associated with destructive periodontal diseases. These enzymes concurrently destroy receptors required for attachment of relatively benign species such as S. mitis and S. sanguis. Thus, the elevated levels of enzymes previously reported present in crevicular fluid and saliva of individuals with poor oral hygiene appear to have the potential to modulate bacterial colonization.

Bacterial Adhesion on Polyelectrolyte Modified Microstructured Titanium Surfaces

2010 ◽  
Vol 1277 ◽  
Author(s):  
Argelia Almaguer-Flores ◽  
Yolloxóchilt R. Sánchez-Cruz ◽  
Jung Hwa Park ◽  
René Olivares-Navarrete ◽  
Michel Dard ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Bacterial Adhesion ◽  
Statistical Significance ◽  
Fusobacterium Nucleatum ◽  
Bacterial Attachment ◽  
Chemical Surface ◽  
Campylobacter Rectus ◽  
Submicron Scale ◽  
Student’S T

Micron-scale and submicron-scale surface roughness enhance osteoblast differentiation on titanium (Ti) substrates and increases bone-to-implant contact in vivo. However, bacterial adhesion is also strongly influenced by roughness and surface chemistry. The aim of this study was to investigate if chemical surface modifications alter initial bacterial attachment. To achieve this, two polyelectrolyte layers [chitosan (Ch) and poly(L-lysine) (PLL)] were used to coat Ti surfaces with different roughness (PT [Ra<0.3μm], SLA [Ra≥3.0μm]). Bacterial attachment was evaluated using Aggregatibacter actinomycetemcomitans, Actinomyces israelii, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Parvimonas micra, Porphyromonas gingivalis, Prevotella intermedia and Streptococcus sanguinis. After 24h incubation, bacteria were detached from the samples with sonication and the counting plate technique was performed to determine the number of colony forming units (CFU's). Additionally, surfaces were observed by scanning electron microscopy to determine bacteria surface coverage. Statistical significance was determined using ANOVA followed by Bonferroni's modification of Student's t-test. The results showed that polyelectrolyte coatings did not affect surface roughness. Modified surfaces were more hydrophilic than the controls. PT surfaces covered by Chi exhibited lower CFUs than the same surface covered by PLL or the control PT (140 × 105/mL, 343 × 105/mL and 283 × 105/mL, respectively). The opposite effect was observed on the SLA surfaces, PLL coated samples shown lower CFUʼs than Chi or uncoated SLA (199 × 105/mL, 229 × 105/mL and 227 × 105/mL, respectively). The Chi layer appeared to reduce bacterial adhesion only on the smooth surfaces. In contrast, PLL coatings reduced bacterial attachment on rougher surfaces. These results suggest that chemical modification of Ti without alteration of surface roughness affects oral bacterial attachment, and could be useful to prevent peri-implantitis related diseases.

scholarly journals QUANTITATIVE DETERMINATION OF SULPHATE REDUCING BACTERIA AND HYDROGEN SULPHIDE IN HUMAN SALIVA

2021 ◽  
Vol 80 (1) ◽  
pp. 35-42
Author(s):  
Qasem M. Abu Shaqra ◽  
Rania M. Al Groom ◽  
Ahmad Al-Gabbiesh
Keyword(s):  
Statistical Significance ◽  
Diagnostic Value ◽  
Human Saliva ◽  
Ion Concentration ◽  
Oral Microbiota ◽  
Oral Manifestations ◽  
Sulphate Reducing Bacteria ◽  
Oral Conditions ◽  
Reducing Bacteria

"Objectives: Sulphate Reducing Bacteria (SRB) are part of the normal oral microbiota. They have been frequently detected in the oral cavity of individuals with and without oral manifestations. The aim of this investigation was to determine possible correlation between SRB count and their activity in saliva versus some oral health manifestations. Methods: A total of 64 saliva samples were collected from healthy individuals, and patients with several oral manifestations. Detection and count of SRB were performed using documented methods, while sulphide ion concentration which is the metabolic end product of these bacteria was measured using a silver electrode connected to a millivolt meter. Results: SRB were detected in 35.9% of saliva samples investigated. Statistical significance was observed between the detection of these bacteria and various oral conditions. However, count of SRB and the sulphide ion concentration in the tested samples did not have significant correlation with the oral conditions considered. Conclusion: The mere detection of SRB in saliva is of significance in the diagnoses of oral conditions. Enumeration of these bacteria and quantification of their metabolic end product in the same samples were not of diagnostic value."

scholarly journals Strategies for Antimicrobial Peptides Immobilization on Surfaces to Prevent Biofilm Growth on Biomedical Devices

Antibiotics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 13
Author(s):  
Mathieu Nicolas ◽  
Bruno Beito ◽  
Marta Oliveira ◽  
Maria Tudela Martins ◽  
Bruno Gallas ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Surface Functionalization ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Biomedical Applications ◽  
Mechanisms Of Action ◽  
Bacterial Attachment ◽  
Biofilm Growth ◽  
Synthetic Routes ◽  
Immobilization Techniques

Nosocomial and medical device-induced biofilm infections affect millions of lives and urgently require innovative preventive approaches. These pathologies have led to the development of numerous antimicrobial strategies, an emergent topic involving both natural and synthetic routes, among which some are currently under testing for clinical approval and use. Antimicrobial peptides (AMPs) are ideal candidates for this fight. Therefore, the strategies involving surface functionalization with AMPs to prevent bacterial attachment/biofilms formation have experienced a tremendous development over the last decade. In this review, we describe the different mechanisms of action by which AMPs prevent bacterial adhesion and/or biofilm formation to better address their potential as anti-infective agents. We additionally analyze AMP immobilization techniques on a variety of materials, with a focus on biomedical applications. Furthermore, we summarize the advances made to date regarding the immobilization strategies of AMPs on various surfaces and their ability to prevent the adhesion of various microorganisms. Progress toward the clinical approval of AMPs in antibiotherapy is also reviewed.

Reduced bacterial adhesion on titanium surfaces micro-structured by ultra-short pulsed laser ablation

2016 ◽  
Vol 17 (1-2) ◽  
Author(s):  
Katharina Doll ◽  
Elena Fadeeva ◽  
Nico S. Stumpp ◽  
Sebastian Grade ◽  
Boris N. Chichkov ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Modern Medicine ◽  
Bacterial Attachment ◽  
Titanium Surfaces ◽  
The Common ◽  
Micro Structures

AbstractImplant-associated infections still pose serious problems in modern medicine. The development of fabrication processes to generate functional surfaces, which inhibit bacterial attachment, is of major importance. Sharklet™-like as well as grooves and grid micro-structures having similar dimensions were fabricated on the common implant material titanium by ultra-short pulsed laser ablation. Investigations on the biofilm formation of

scholarly journals Biofilm Formation in Xanthomonas arboricola pv. pruni: Structure and Development

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 546
Author(s):  
Pilar Sabuquillo ◽  
Jaime Cubero
Keyword(s):  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Environmental Changes ◽  
Nutrient Content ◽  
Infection Process ◽  
Bacterial Attachment ◽  
Key Factors ◽  
Cell Structures ◽  
Microscopy Techniques

Xanthomonasarboricola pv. pruni (Xap) causes bacterial spot of stone fruit and almond, an important plant disease with a high economic impact. Biofilm formation is one of the mechanisms that microbial communities use to adapt to environmental changes and to survive and colonize plants. Herein, biofilm formation by Xap was analyzed on abiotic and biotic surfaces using different microscopy techniques which allowed characterization of the different biofilm stages compared to the planktonic condition. All Xap strains assayed were able to form real biofilms creating organized structures comprised by viable cells. Xap in biofilms differentiated from free-living bacteria forming complex matrix-encased multicellular structures which become surrounded by a network of extracellular polymeric substances (EPS). Moreover, nutrient content of the environment and bacterial growth have been shown as key factors for biofilm formation and its development. Besides, this is the first work where different cell structures involved in bacterial attachment and aggregation have been identified during Xap biofilm progression. Our findings provide insights regarding different aspects of the biofilm formation of Xap which improve our understanding of the bacterial infection process occurred in Prunus spp and that may help in future disease control approaches.

scholarly journals HRV analysis: undependability of approximate entropy at locating optimum complexity in malnourished children

2021 ◽  
pp. 1-6
Author(s):  
David M. Garner ◽  
Gláucia S. Barreto ◽  
Vitor E. Valenti ◽  
Franciele M. Vanderlei ◽  
Andrey A. Porto ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Accurate Determination ◽  
Approximate Entropy ◽  
Effect Sizes ◽  
Potential Hazard ◽  
Autonomic Modulation ◽  
Embedding Dimension ◽  
Malnourished Children ◽  
Hrv Analysis

Abstract Introduction: Approximate Entropy is an extensively enforced metric to evaluate chaotic responses and irregularities of RR intervals sourced from an eletrocardiogram. However, to estimate their responses, it has one major problem – the accurate determination of tolerances and embedding dimensions. So, we aimed to overt this potential hazard by calculating numerous alternatives to detect their optimality in malnourished children. Materials and methods: We evaluated 70 subjects split equally: malnourished children and controls. To estimate autonomic modulation, the heart rate was measured lacking any physical, sensory or pharmacologic stimuli. In the time series attained, Approximate Entropy was computed for tolerance (0.1→0.5 in intervals of 0.1) and embedding dimension (1→5 in intervals of 1) and the statistical significances between the groups by their Cohen’s ds and Hedges’s gs were totalled. Results: The uppermost value of statistical significance accomplished for the effect sizes for any of the combinations was −0.2897 (Cohen’s ds) and −0.2865 (Hedges’s gs). This was achieved with embedding dimension = 5 and tolerance = 0.3. Conclusions: Approximate Entropy was able to identify a reduction in chaotic response via malnourished children. The best values of embedding dimension and tolerance of the Approximate Entropy to identify malnourished children were, respectively, embedding dimension = 5 and embedding tolerance = 0.3. Nevertheless, Approximate Entropy is still an unreliable mathematical marker to regulate this.

scholarly journals Bond Strengthening in Oral Bacterial Adhesion to Salivary Conditioning Films

2008 ◽  
Vol 74 (17) ◽  
pp. 5511-5515 ◽  
Author(s):  
Henny C. van der Mei ◽  
Minie Rustema-Abbing ◽  
Joop de Vries ◽  
Henk J. Busscher
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Specific Interactions ◽  
Adhesion Forces ◽  
Bacterial Strains ◽  
Bacterial Interactions ◽  
Initial Adhesion ◽  
Conditioning Film ◽  
Interacting Surfaces ◽  
Conditioning Films

ABSTRACT Transition from reversible to irreversible bacterial adhesion is a highly relevant but poorly understood step in initial biofilm formation. We hypothesize that in oral biofilm formation, irreversible adhesion is caused by bond strengthening due to specific bacterial interactions with salivary conditioning films. Here, we compared the initial adhesion of six oral bacterial strains to salivary conditioning films with their adhesion to a bovine serum albumin (BSA) coating and related their adhesion to the strengthening of the binding forces measured with bacteria-coated atomic force microscopy cantilevers. All strains adhered in higher numbers to salivary conditioning films than to BSA coatings, and specific bacterial interactions with salivary conditioning films were accompanied by stronger initial adhesion forces. Bond strengthening occurred on a time scale of several tens of seconds and was slower for actinomyces than for streptococci. Nonspecific interactions between bacteria and BSA coatings strengthened twofold faster than their specific interactions with salivary conditioning films, likely because specific interactions require a closer approach of interacting surfaces with the removal of interfacial water and a more extensive rearrangement of surface structures. After bond strengthening, bacterial adhesion forces with a salivary conditioning film remained stronger than those with BSA coatings.

Determination of Ethnic Variation in Infant Nasolabial Anthropometry Using 3D Photographs: Implications for Bilateral Cleft Lip Nasal Correction

2021 ◽  
pp. 105566562110244
Author(s):  
Diana S. Jodeh ◽  
Jacqueline M. Ross ◽  
Maria Leszczynska ◽  
Fatima Qamar ◽  
Rachel L. Dawkins ◽  
...  
Keyword(s):  
African American ◽  
Interrater Reliability ◽  
Cleft Lip ◽  
Pearson Correlation ◽  
Statistical Significance ◽  
3D Analysis ◽  
Pediatric Clinic ◽  
Bilateral Cleft Lip ◽  
Post Hoc

Objective: We aimed to assess significant ethnic variabilities in infants’ nasolabial anthropometry to motivate variations in surgical correction of a synchronous bilateral cleft lip/nasal anomaly, specifically whether a long columella is a European feature, therefore accepting a short columella and/or delayed columellar lengthening suitable for reconstruction in ethnic patients. Methods: Thirty-three infants without craniofacial pathology (10 African American [AA], 7 Hispanic [H], and 16 of European descent [C]), ages 3 to 8 months, presenting to the Johns Hopkins All Children’s general pediatric clinic were recruited. Four separate 3D photographs (2 submental and frontal views each) were taken using the Vectra H1 handheld camera (Canfield Imaging). Eighteen linear facial distances were measured using Mirror 3D analysis (Canfield Imaging Systems). Difference between ethnicities was measured using analysis of variance with the Bonferroni/Dunn post hoc comparisons. Pearson correlation was employed for interrater reliability. All statistical analyses were carried out using SPSS version 21.0 (IBM Corp), with statistical significance set at P < .05. Results: Nasal projection (sn-prn) and columella length (sn-c) did not differ significantly between groups ( P = .9). Significant differences were seen between ethnic groups in nasal width (sbal-sbal [C-AA; P = .02]; ac-ac [C-AA; P = .00; H-AA; P = .04]; al-al [C-AA; P = .00; H-AA; P = .001]) and labial length (sn-ls [C-AA; P = .041]; sn-sto [C-AA; P = .005]; Cphs-Cphi L [C-AA; P = .013]; Cphs-Cphi R [C-AA; P = .015]). Interrater reliability was good to excellent and significantly correlated for all measures. Conclusions: African American infants exhibited wider noses and longer lips. No difference was noted in nasal projection or columella length, indicating that these structures should be corrected during the primary cleft lip and nasal repair for all patients and should not be deferred to secondary correction.

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