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Oral biofilm

Y F Zhang, D Y Li, J X Yu, H T He
OBJECTIVE: To determine the thickness and nanomechanical properties of salivary pellicle formed on tooth enamel. METHODS: In vitro adsorption experiments were conducted by immersing enamel samples in centrifuged saliva for 1min, and then the nanomechanical properties of the salivary pellicle/tooth enamel system were measured firstly using nanoindentation based on a continuous stiffness measurement technique. Finally, a model was proposed to obtain the thickness and the intrinsic nanohardness of this biofilm...
October 19, 2016: Journal of Dentistry
Mor Shlezinger, Yael Houri-Haddad, Shunit Coppenhagen-Glazer, Grégory Resch, Yok-Ai Que, Shaul Beyth, Elisheva Dorfman, Ronen Hazan, Nurit Beyth
Dental diseases are perhaps the most prevalent infection-related diseases in humans. Biofilm is involved in almost every infectious disease compromising oral health, notably caries, periodontal disease, gingivitis, endodontic infections and peri-implantitis. Current therapies of biofilm-derived oral infections lack sensitivity; they are not species-specific and kill pathogenic species as well as commensal species, which are protective against the formation of pathogenic biofilms. Moreover, antibiotics have a limited effect on biofilm and are almost unused in oral diseases...
September 30, 2016: Current Topics in Medicinal Chemistry
N Rostami, R C Shields, S A Yassin, A R Hawkins, L Bowen, T L Luo, A H Rickard, R Holliday, P M Preshaw, N S Jakubovics
Extracellular DNA (eDNA) has been identified in the matrix of many different monospecies biofilms in vitro, including some of those produced by oral bacteria. In many cases, eDNA stabilizes the structure of monospecies biofilms. Here, the authors aimed to determine whether eDNA is an important component of natural, mixed-species oral biofilms, such as plaque on natural teeth or dental implants. To visualize eDNA in oral biofilms, approaches for fluorescently stained eDNA with either anti-DNA antibodies or an ultrasensitive cell-impermeant dye, YOYO-1, were first developed using Enterococcus faecalis, an organism that has previously been shown to produce extensive eDNA structures within biofilms...
October 21, 2016: Journal of Dental Research
A Reum Kim, Ki Bum Ahn, Hyun Young Kim, Ho Seong Seo, Cheol-Heui Yun, Seung Hyun Han
INTRODUCTION: Streptococcus gordonii is a predominant member of the oral microflora and has been isolated from root canals of teeth with refractory apical periodontitis. Biofilm formation is important for various dental diseases, and S. gordonii is involved in dental biofilm formation as an early colonizer. Although serine-rich repeat (SRR) adhesins of S. gordonii such as gordonii surface protein B (GspB) are associated with bacterial colonization, the role of GspB in biofilm formation is not clearly understood...
October 18, 2016: Journal of Endodontics
Karolina Niska, Narcyz Knap, Anna Kędzia, Maciej Jaskiewicz, Wojciech Kamysz, Iwona Inkielewicz-Stepniak
Objectives: In dentistry, silver nanoparticles (AgNPs) have drawn particular attention because of their wide antimicrobial activity spectrum. However, controversial information on AgNPs toxicity limited their use in oral infections. Therefore, the aim of the present study was to evaluate the antibacterial activities against a panel of oral pathogenic bacteria and bacterial biofilms together with potential cytotoxic effects on human gingival fibroblasts of 10 nm AgNPs: non-functionalized - uncapped (AgNPs-UC) as well as surface-functionalized with capping agent: lipoic acid (AgNPs-LA), polyethylene glycol (AgNPs-PEG) or tannic acid (AgNPs-TA) using silver nitrate (AgNO3) as control...
2016: International Journal of Medical Sciences
Zaleha Shafiei, Zubaidah Haji Abdul Rahim, Koshy Philip, Nalina Thurairajah
BACKGROUND: Plant extracts mixture (PEM) and its individual constituent plant extracts(Psidium sp., Mangifera sp., Mentha sp.) are known to have an anti-adhering effect towards oral bacteria in the single-species biofilm. To date, the adhering ability of the early and late plaque colonisers (Streptococcus sanguinis and Streptococcus mutans) to PEM-treated experimental pellicle have not been investigated in dual-species biofilms. METHODS: Fresh leaves of these plants were used in the preparation of the respective aqueous extract decoctions...
2016: PeerJ
Rahul Pal, Saif Hameed, Sharda Sharma, Zeeshan Fatima
Novel strategies to combat the ever increasing burden of drug resistance in Mycobacterium tuberculosis (MTB) causing tuberculosis (TB) remains a global concern. The ability of MTB to sense and adapt to restricted iron conditions in the hostile environment is essential for their survival and confers the basis of their success as dreadful pathogen. The striking and clinically relevant virulence trait of MTB is its ability to form biofilms and adhere to the host cells. The present study elucidated the effect of iron deprivation on biofilm formation and cell adherence of Mycobacterium smegmatis, a non-pathogenic surrogate of MTB...
October 15, 2016: Brazilian Journal of Infectious Diseases
Marika Rai, David Spratt, Paola R Gomez-Pereira, Jay Patel, Sean P Nair
Oral malodour is a common condition which affects a large proportion of the population, resulting in social, emotional and psychological stress. Certain oral bacteria form a coating called a biofilm on the tongue dorsum and degrade organic compounds releasing volatile sulfur compounds that are malodourous. Current chemical treatments for oral malodour such as mouthwashes containing chlorhexidine or essential oils, are not sufficiently effective at reducing the bacterial load on the tongue. One potential alternative to current chemical treatments for oral malodour is the use of light activated antimicrobial agents (LAAAs), which display no toxicity or antimicrobial activity in the dark, but when exposed to light of a specific wavelength produce reactive oxygen species which induce damage to target cells in a process known as photodynamic inactivation...
October 18, 2016: Journal of Breath Research
S S Garcia, Q Du, H Wu
The oral cavity is a dynamic environment characterized by hundreds of bacterial species, saliva, and an influx of nutrients and metal ions such as copper. Although there is a physiologic level of copper in the saliva, the oral cavity is often challenged with an influx of copper ions. At high concentrations copper is toxic and must therefore be strictly regulated by pathogens for them to persist and cause disease. The cariogenic pathogen Streptococcus mutans manages excess copper using the copYAZ operon that encodes a negative DNA-binding repressor (CopY), the P1-ATPase copper exporter (CopA), and the copper chaperone (CopZ)...
December 21, 2015: Molecular Oral Microbiology
Jin Xiao, Yonghwi Moon, Lihua Li, Elena Rustchenko, Hironao Wakabayashi, Xiaoyi Zhao, Changyong Feng, Steven R Gill, Sean McLaren, Hans Malmstrom, Yanfang Ren, Robert Quivey, Hyun Koo, Dorota T Kopycka-Kedzierawski
INTRODUCTION: Candida albicans has been detected together with Streptococcus mutans in high numbers in plaque-biofilm from children with early childhood caries (ECC). The goal of this study was to examine the C. albicans carriage in children with severe early childhood caries (S-ECC) and the maternal relatedness. METHODS: Subjects in this pilot cross-sectional study were recruited based on a convenient sample. DMFT(S)/dmft(s) caries and plaque scores were assessed during a comprehensive oral exam...
2016: PloS One
Yuan Wei, Wei Qiu, Xue-Dong Zhou, Xin Zheng, Ke-Ke Zhang, Shi-Da Wang, Yu-Qing Li, Lei Cheng, Ji-Yao Li, Xin Xu, Ming-Yun Li
D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial cell wall synthesis. Alanine racemase (Alr) is a unique enzyme that interconverts L-alanine and D-alanine in most bacteria, making this enzyme a potential target for antimicrobial drug development. Streptococcus mutans is a major causative factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Alr in S...
October 14, 2016: International Journal of Oral Science
Hang Yang, Yongli Bi, Xiaoran Shang, Mengyue Wang, Sara B Linden, Yunpeng Li, Yuhong Li, Daniel C Nelson, Hongping Wei
Streptococcus mutans often survives as a biofilm on the tooth surface and contributes to the development of dental caries. We investigated the efficacy of ClyR, an engineered chimeolysin, against S. mutans biofilms in physiological and cariogenic conditions. Susceptibility tests showed that ClyR was active against all clinical S. mutans isolates tested as well as S. mutans biofilms that displayed resistance to penicillin. S. mutans biofilms formed on hydroxyapatite discs in physiological sugar conditions and cariogenic conditions were reduced ∼2 logs and 3 logs after treatment with 100 μg/ml ClyR, respectively...
October 10, 2016: Antimicrobial Agents and Chemotherapy
Jeffrey B Kaplan, Vandana Sampathkumar, Meriem Bendaoud, Alexander K Giannakakis, Edward T Lally, Nataliya V Balashova
The Gram-negative bacterium Kingella kingae is part of the normal oropharyngeal mucosal flora of children under four years old. K. kingae can enter the submucosa and cause infections of the skeletal system in children including septic arthritis and osteomyelitis. The organism is also associated with infective endocarditis in children and adults. Although biofilm formation has been coupled with pharyngeal colonization, osteoarticular infections, and infective endocarditis, no studies have investigated biofilm formation in K...
October 7, 2016: Molecular Oral Microbiology
Barbara Klug, Elisabeth Santigli, Christian Westendorf, Stefan Tangl, Gernot Wimmer, Martin Grube
Background: Oral biofilm studies based on simplified experimental setups are difficult to interpret. Models are limited mostly by the number of bacterial species observed and the insufficiency of artificial media. Few studies have attempted to overcome these limitations and to cultivate native oral biofilm. Aims: This study aimed to grow oral biofilm in vivo before transfer to a biofilm reactor for ex situ incubation. The in vitro survival of this oral biofilm and the changes in bacterial composition over time were observed...
2016: Frontiers in Microbiology
Tomoka Ueno, Yasushi Shimada, Khairul Matin, Yuan Zhou, Ikumi Wada, Alireza Sadr, Yasunori Sumi, Junji Tagami
The aim of this study was to evaluate the signal intensity and signal attenuation of swept source optical coherence tomography (SS-OCT) for dental caries in relation to the variation of mineral density. SS-OCT observation was performed on the enamel and dentin artificial demineralization and on natural caries. The artificial caries model on enamel and dentin surfaces was created using Streptococcus mutans biofilms incubated in an oral biofilm reactor. The lesions were centrally cross sectioned and SS-OCT scans were obtained in two directions to construct a three-dimensional data set, from the lesion surface (sagittal scan) and parallel to the lesion surface (horizontal scan)...
July 2016: Journal of Medical Imaging
Ana-Paula-Rodrigues Magalhães, Francine-Couto-Lima Moreira, Denise-Ramos-Silveira Alves, Cyntia-Rodrigues-Araújo Estrela, Carlos Estrela, Marcus-Santos Carrião, Andris-Figueiroa Bakuzis, Lawrence-Gonzaga Lopes
BACKGROUND: Silver has a long history of use in medicine as an antimicrobial and anti-inflammatory agent. Silver nanoparticles (NAg) offer the possibility to control the formation oral biofilms through the use of nanoparticles with biocidal, anti-adhesive, and delivery abilities. This study aims to evaluate the antibacterial effect of resin luting cements with and without NAg, and their influence on color, sorption and solubility. MATERIAL AND METHODS: NAg were incorporated to two dual-cured resin cements (RelyX ARC (RA) color A1 and RelyX U200 (RU) color A2) in two concentrations (0...
October 2016: Journal of Clinical and Experimental Dentistry
Glenda N Rossi, Ana L Sorazabal, Pablo A Salgado, Aldo F Squassi, Graciela L Klemonskis
The aim of this study was to establish the association between features regarding brushing procedure performed by schoolchildren without previous formal training and the effectiveness of biofilm removal. Out of a population of 8900 6- and 7-year-old schoolchildren in Buenos Aires City, 600 children were selected from schools located in homogeneous risk areas. Informed consent was requested from parents or guardians and formal assent was obtained from children themselves. The final sample consisted of 316 subjects...
April 2016: Acta Odontológica Latinoamericana: AOL
Lopez-Nguyen Darrene, Badet Cecile
The oral ecosystem is a very complex environment where more than 700 different bacterial species can be found. Most of them are organized in biofilm on dental and mucosal surfaces. Studying this community is important because a rupture in stability can lead to the preeminence of pathogenic microorganisms, causing dental decay, gingivitis, or periodontitis. The multitude of species complicates biofilm analysis so its reproduction, collection, and counting are very delicate. The development of experimental models of dental biofilms was therefore essential and multiple in vitro designs have emerged, each of them especially adapted to observing biofilm formation of specific bacteria within specific environments...
2016: BioMed Research International
Yoshihiro Ojima, Shota Nunogami, Masahito Taya
Enhancement of microbial biofilm formation by low antimicrobial doses is a critical problem in the medical field. The objective of this study was to propose a new drug candidate against the biofilm formation promoted by subinhibitory dose of antimicrobials. To determine the effect on biofilm formation of Escherichia coli, a subinhibitory concentration of lactoferrin (LF), a milk protein involved in a broad range of biological properties including antimicrobial action, or ampicillin (AMP), a typical antibiotic, was added to an E...
September 19, 2016: Journal of Global Antimicrobial Resistance
Alison Marshall, Antonio Celentano, Nicola Cirillo, Michele D Mignogna, Michael McCullough, Stephen Porter
Chemokine (C-X-C motif) ligand (CXCL)9 and CXCL10 are dysregulated in oral inflammatory conditions, and it is not known if these chemokines target microorganisms that form oral biofilm. The aim of this study was to investigate the antimicrobial activity of CXCL9 and CXCL10 on oral microflora and their expression profiles in oral keratinocytes following exposure to inflammatory and infectious stimuli. Streptococcus sanguinis was used as a model and Escherichia coli as a positive control. The antimicrobial effect of CXCL9/CXCL10 was tested using a radial diffusion assay...
October 2016: European Journal of Oral Sciences
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