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bacteria biofilm

Vincent Poot, Maaike Hoekstra, Mitchell A A Geleijnse, Mark C M van Loosdrecht, Julio Pérez
Partial nitritation was stably achieved in a bench-scale airlift reactor (1.5L) containing granular sludge. Continuous operation at 20 °C treating low-strength synthetic wastewater (50 mg N-NH4(+)/L and no COD) achieved nitrogen loading rates of 0.8 g N-NH4(+)/(L·d) during partial nitritation. The switch between nitrite-oxidizing bacteria (NOB) repression and NOB proliferation was observed when ammonium concentrations in the reactor were below 2-5 mg N-NH4(+)/L for DO concentrations lower than 4 mg O2/L at 20 °C...
October 11, 2016: Water Research
Katsuhiko Hirota, Hiromichi Yumoto, Bayarmagnai Sapaar, Takashi Matsuo, Tetsuo Ichikawa, Yoichiro Miyake
Candida albicans is commonly found as a member of the human microflora and a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various microorganisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases...
October 21, 2016: Journal of Applied Microbiology
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
Ivana Nedeljkovic, Kumiko Yoshihara, Jan De Munck, Wim Teughels, Bart Van Meerbeek, Kirsten L Van Landuyt
BACKGROUND: In spite of contradicting results, the high susceptibility of composites for secondary caries is still often associated with the bacterial growth-stimulating effect of released methacrylate monomers. However, most studies that showed this effect were performed with techniques having inherent limitations (spectrophotometry). OBJECTIVES: Therefore, our objective was to determine the effect of four methacrylate monomers (2-Hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA), ethylene glycol dimethacrylate (EGDMA), diethylene glycol dimethacrylate (DEGDMA)) on the growth of two caries-associated bacteria, Streptococcus mutans and sobrinus, and one non-cariogenic species, Streptococcus sanguinis, using TaqMan quantitative polymerase chain reaction (qPCR) to quantify bacterial DNA...
October 20, 2016: Clinical Oral Investigations
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
Wei Qiu, Biao Ren, Huanqin Dai, Lixin Zhang, Qiong Zhang, Xuedong Zhou, Yuqing Li
OBJECTIVE: The aim of this study was to determine the inhibitory effect of eight antifungal drugs on S. mutans growth, biofilm formation and virulence factors. METHODS: The actions of antifungal drugs on S. mutans were determined by recovery plates and survival kinetic curves. Biofilms were observed by scanning electron microscopy and the viable cells were recovered on BHI plates, meanwhile biofilms were stained by BacLight live/dead kit to investigate the biofilm viability...
October 13, 2016: Archives of Oral Biology
Julia I Tandberg, Leidy X Lagos, Petter Langlete, Eva Berger, Anne-Lise Rishovd, Norbert Roos, Deepa Varkey, Ian T Paulsen, Hanne C Winther-Larsen
Membrane vesicles (MVs) are spherical particles naturally released from the membrane of Gram-negative bacteria. Bacterial MV production is associated with a range of phenotypes including biofilm formation, horizontal gene transfer, toxin delivery, modulation of host immune responses and virulence. This study reports comparative profiling of MVs from bacterial strains isolated from three widely disperse geographical areas. Mass spectrometry identified 119, 159 and 142 proteins in MVs from three different strains of Piscirickettsia salmonis isolated from salmonids in Chile (LF-89), Norway (NVI 5692) and Canada (NVI 5892), respectively...
2016: PloS One
Şivge Kurgan, Shevali Kansal, Daniel Nguyen, Danielle Stephens, Yannis Koroneos, Hatice Hasturk, Thomas E Van Dyke, Alpdogan Kantarci
BACKGROUND: Neutrophil function is critical for the initiation and progression of infecto-inflammatory diseases. Key quorum-sensing plaque bacteria such as Fusobacterium nucleatum act as bridging species between early and late colonizer pathogens such as Porphyromonas gingivalis as the biofilm ages and periodontal inflammation increases. This study was designed to determine the impact of different F. nucleatum strains on neutrophil function. MATERIALS AND METHODS: HL-60 cells were differentiated into neutrophil-like cells and cultured with F...
October 20, 2016: Journal of Periodontology
Jingqing Liu, Hongxing Ren, Xianbei Ye, Wei Wang, Yan Liu, Liping Lou, Dongqing Cheng, Xiaofang He, Xiaoyan Zhou, Shangde Qiu, Liusong Fu, Baolan Hu
Biofilms in the pipe wall may lead to water quality deterioration and biological instability in drinking water distribution systems (DWDSs). In this study, bacterial community radial-spatial distribution in biofilms along the pipe wall in a chlorinated DWDS of East China was investigated. Three pipes of large diameter (300, 600, and 600 mm) were sampled in this DWDS, including a ductile cast iron pipe (DCIP) with pipe age of 11 years and two gray cast iron pipes (GCIP) with pipe ages of 17 and 19 years, and biofilms in the upper, middle, and lower parts of each pipe wall were collected...
October 19, 2016: Applied Microbiology and Biotechnology
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
Olga Besharova, Verena M Suchanek, Raimo Hartmann, Knut Drescher, Victor Sourjik
Many bacteria primarily exist in nature as structured multicellular communities, so called biofilms. Biofilm formation is a highly regulated process that includes the transition from the motile planktonic to sessile biofilm lifestyle. Cellular differentiation within a biofilm is a commonly accepted concept but it remains largely unclear when, where and how exactly such differentiation arises. Here we used fluorescent transcriptional reporters to quantitatively analyze spatio-temporal expression patterns of several groups of genes during the formation of submerged Escherichia coli biofilms in an open static system...
2016: Frontiers in Microbiology
H Y Shi, Q D Li, X Y Wan
Objective: To investigate the destructive effects of erythromycin on biofilm of MRSA and find the effect of erythromycin on QS related factors. Methods: Tested the MBC of erythromycin on MRSA.Established the model of biofilm.Erythromycin was added into the medium when bacteria were inoculated for 24 h. Tested the biofilm and collected the supernatant or serum of rat at 6, 12, 24, 48, 72 h and 7 d after adding erythromycin to detect the concentration of autoinducing peptides (AIP). Results: The MBC of the erythromycin on standard strains of MRSA was 256 g/L...
October 11, 2016: Zhonghua Yi Xue za Zhi [Chinese medical journal]
Lyudmila Boyanova, Rumyana Markovska, Ivan Mitov
This review focuses on the virulence arsenal of the most pathogenic species among Gram positive anaerobic cocci, Finegoldia magna according to recently published data from 2012-2016. Virulence factors like sortase dependent pili and F. magna adhesion factor (FAF) facilitate the start of the infection. Albumin binding protein (PAB) enhances F. magna survival. FAF, subtilisin-like extracellular serine protease (SufA) and superantigen protein L protect the bacteria from factors of innate defense system. SufA, capsule and tissue-destroying enzymes provide a deep penetration or spread of the infections and the protein L is associated with infection severity...
October 15, 2016: Anaerobe
Irfan Ahmad, Syed Fazle Rouf, Lei Sun, Annika Cimdins, Sulman Shafeeq, Soazig Le Guyon, Marco Schottkowski, Mikael Rhen, Ute Römling
BACKGROUND: Cellulose, a 1,4 beta-glucan polysaccharide, is produced by a variety of organisms including bacteria. Although the production of cellulose has a high biological, ecological and economical impact, regulatory mechanisms of cellulose biosynthesis are mostly unknown. Family eight cellulases are regularly associated with cellulose biosynthesis operons in bacteria; however, their function is poorly characterized. In this study, we analysed the role of the cellulase BcsZ encoded by the bcsABZC cellulose biosynthesis operon of Salmonella enterica serovar Typhimurium (S...
October 19, 2016: Microbial Cell Factories
Todd Atherly, Curtis Mosher, Chong Wang, Jesse Hostetter, Alexandra Proctor, Meghan W Brand, Gregory J Phillips, Michael Wannemuehler, Albert E Jergens
BACKGROUND: Helicobacter bilis infection of C3H/HeN mice harboring the altered Schaedler flora (ASF) triggers progressive immune responsiveness and the development of colitis. We sought to investigate temporal alterations in community structure of a defined (ASF-colonized) microbiota in normal and inflamed murine intestines and to correlate microbiota changes to histopathologic lesions. METHODS: The colonic mucosal microbiota of healthy mice and ASF mice colonized with H...
November 2016: Inflammatory Bowel 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
Mareike Klinger-Strobel, Oliwia Makarewicz, Mathias W Pletz, Andreas Stallmach, Christian Lautenschläger
Biofilm formation, also known as microfouling, on indwelling medical devices such as catheters or prosthetic joints causes difficult to treat and recurrent infections. It is also the initial step for biocorrosion of surfaces in aquatic environment. An efficient prevention of microfouling is preferable but the development of antibiofilm surfaces is enormously challenging. Therefore, soda-lime, aluminosilicate, and three borosilicate glasses with different TiO2 and ZnO compositions were investigated on their feasibility to prevent biofilm formation by standardized in vitro biofilm assays using different pathogenic bacteria...
December 2016: Journal of Materials Science. Materials in Medicine
Mehdi Molaei, Jian Sheng
Understanding how bacteria move close to a surface under various stimuli is crucial for a broad range of microbial processes including biofilm formation, bacterial transport and migration. While prior studies focus on interactions between single stimulus and bacterial suspension, we emphasize on compounding effects of flow shear and solid surfaces on bacterial motility, especially reorientation and tumble. We have applied microfluidics and digital holographic microscopy to capture a large number (>10(5)) of 3D Escherichia coli trajectories near a surface under various flow shear...
October 18, 2016: Scientific Reports
M E Galarraga-Vinueza, J Mesquita-Guimarães, R S Magini, J C M Souza, M C Fredel, A R Boccaccini
Bioactive glasses (BGs) are promising materials for bone repair due to their desirable properties such as osteoconductivity, biodegradability, angiogenic potential, and antibacterial activity. Ionic dissolution products from bioactive glasses increase the medium pH reducing surrounding bacteria proliferation. The activity of BGs against biofilm formation has been enhanced by incorporating organic antibacterial compounds. The aim of this review was to summarize evidence in literature which assesses the efficacy of antibacterial and anti-biofilm compounds embedded in bioactive glasses to prevent peri-implant infection during bone healing...
October 17, 2016: Journal of Biomedical Materials Research. Part A
Cristian Picioreanu, Julio Pérez, Mark C M van Loosdrecht
A three-dimensional (3-D) diffusion-reaction model was used to assess the effects of nitrifiers growing in cell clusters on the apparent oxygen half-saturation coefficients in activated sludge flocs. The model allows conciliation of seemingly contradictory reports by several research groups. Although intrinsic half-saturation coefficients (i.e., not affected by diffusion) show a better affinity for oxygen for ammonia oxidizing (AOB) than for nitrite oxidizing bacteria (NOB) (KO,AOB < KO,NOB), measurements in flocs often produced reversed apparent values (KO,AOB,app > KO,NOB,app), which can now be explained by the 3-D model with AOB and NOB microcolonies...
October 8, 2016: Water Research
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