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Biofilm formation

José Andrés Medrano-Félix, Cristóbal Chaidez, Kristina D Mena, María Del Socorro Soto-Galindo, Nohelia Castro-Del Campo
Survival of bacterial pathogens in different environments is due, in part, to their ability to form biofilms. Four wild-type Salmonella enterica strains, two Oranienburg and two Saintpaul isolated from river water and animal feces, were tested for biofilm formation at the air-liquid interface under stressful conditions (pH and salinity treatments such as pH 3, NaCl 4.5 w/v; pH 7, NaCl 4.5 w/v; pH 10, NaCl 4.5 w/v; pH 3, Nacl 0.5 w/v; pH 7, NaCl 0.5 w/v; and pH 10, NaCl 0.5 w/v); Salmonella Typhimurium DT104 was used as a control strain...
March 15, 2018: Environmental Monitoring and Assessment
Stefanie Amend, Roland Frankenberger, Susanne Lücker, Eugen Domann, Norbert Krämer
OBJECTIVES: The present study aimed to establish Lactobacillus casei in a completely automated Streptococcus mutans-based artificial mouth model and to investigate secondary caries inhibiting properties of glass ionomer cements / resin composite groups in vitro. METHODS: Sixty extracted, caries-free human third molars were used for preparation of standardized class-V-cavities. Specimens were restored with a resin-modified (Photac Fil; PF) as well as a conventional glass ionomer cement (Ketac Molar; KM) and one resin composite bonded with and without conduction of etch-and-rinse technique (Prime&Bond NT, Ceram X mono; C+ERT, C)...
March 12, 2018: Dental Materials: Official Publication of the Academy of Dental Materials
Olivier Poupel, Caroline Proux, Bernd Jagla, Tarek Msadek, Sarah Dubrac
The success of Staphylococcus aureus, as both a human and animal pathogen, stems from its ability to rapidly adapt to a wide spectrum of environmental conditions. Two-component systems (TCSs) play a crucial role in this process. Here, we describe a novel staphylococcal virulence factor, SpdC, an Abi-domain protein, involved in signal sensing and/or transduction. We have uncovered a functional link between the WalKR essential TCS and the SpdC Abi membrane protein. Expression of spdC is positively regulated by the WalKR system and, in turn, SpdC negatively controls WalKR regulon genes, effectively constituting a negative feedback loop...
March 2018: PLoS Pathogens
Quintin Borgersen, David T Bolick, Glynis L Kolling, Matthew Aijuka, Fernando Ruiz-Perez, Richard L Guerrant, James P Nataro, Araceli E Santiago
Enteroaggregative E. coli (EAEC) is associated with food-borne outbreaks of diarrhea and growth faltering among children in developing countries. A Shiga toxin-producing EAEC strain of serotype O104:H4 strain caused one of the largest outbreaks of a food-borne infection in Europe in 2011. The outbreak was traced to contaminated fenugreek sprouts, yet the mechanisms whereby such persistent contamination of sprouts could have occurred are not clear. We found that under ambient conditions of temperature and in minimal media, pathogenic Shiga toxin-producing EAEC O104:H4 227-11 and non-Shiga toxin-producing 042 strains both produce high levels of exopolysaccharide structures (EPS) that are released to the external milieu...
March 15, 2018: Gut Microbes
Neerupma Bhardwaj, Kirtimaan Syal, Dipankar Chatterji
ppGpp, an alarmone for stringent response, plays an important role in the reprogramming of the transcription complex at the time of stress. In Escherichia coli, ppGpp mediates its action by binding to at least two different sites on RNA polymerase (RNAP). One of the sites to which ppGpp binds to RNAP is at the β'-ω interface; however, the underlying molecular mechanism and the physiological relevance of ppGpp binding to this site remain unclear. In this study, we have performed UV cross-linking experiments using32 P azido-labeled ppGpp to probe its association with RNAP in the absence and presence of ω, and observed weaker binding of ppGpp to the RNAP without ω...
March 15, 2018: Genes to Cells: Devoted to Molecular & Cellular Mechanisms
Brijesh Kumar, John L Sorensen, Silvia T Cardona
Burkholderia cenocepacia is an opportunistic bacterium that can thrive in different environments, including the amino acid-rich mucus of the cystic fibrosis (CF) lung. B. cenocepacia responds to the nutritional conditions that mimic the CF sputum by increasing flagellin expression and swimming motility. Individual amino acids also induce swimming but not flagellin expression. Here, we show that modulation of the second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) levels by the PAS-containing c-di-GMP phosphodiesterase, BCAL1069 (CdpA), regulates the swimming motility of B...
2018: Frontiers in Cellular and Infection Microbiology
Qian Liu, Yang Yang, Xiaoxue Mei, Bingfeng Liu, Chuan Chen, Defeng Xing
Ferric iron can affect the current generation of microbial electrochemical system (MES); however, how it influences microbial biofilm formation and metabolic activity has not been reported. Here, we describe the response of microbial electrode biofilm communities to insoluble ferric iron (Fe3+ ) at different concentrations in microbial fuel cells (MFCs). Insoluble ferric iron (200μM) improved electrochemical activity of the MFCs microbial biofilms during start-up and resulted in a higher maximum power density of 0...
March 11, 2018: Science of the Total Environment
Ripon Sarkar, Aritri Ghosh, Ananya Barui, Pallab Datta
Topical application of honey for tissue regeneration, has recently regained attention in clinical practice with controlled studies affirming its efficacy and indicating its role in regeneration over repair. Parallely, to overcome difficulties of applying raw honey, several product development studies like nanofibrous matrices have been reported. However, one approach concentrated on achieving highest possible honey loading in the nanofiber membranes while other studies have found that only specific honey dilutions result in differential cellular responses on wound healing and re-epithelization...
March 13, 2018: Journal of Materials Science. Materials in Medicine
Arwa Abu Khweek, Amal O Amer
Legionella pneumophila ( L. pneumophila ) is an opportunistic waterborne pathogen and the causative agent for Legionnaires' disease, which is transmitted to humans via inhalation of contaminated water droplets. The bacterium is able to colonize a variety of man-made water systems such as cooling towers, spas, and dental lines and is widely distributed in multiple niches, including several species of protozoa In addition to survival in planktonic phase, L. pneumophila is able to survive and persist within multi-species biofilms that cover surfaces within water systems...
2018: Frontiers in Cellular and Infection Microbiology
Ki Bum Ahn, Jung Eun Baik, Cheol-Heui Yun, Seung Hyun Han
A biofilm is an aggregate of microorganisms in which cells adhere to biological or non-biological surfaces and is responsible for various infectious diseases. Infections caused by Staphylococcus aureus , including pneumonia, endocarditis, and osteomyelitis, are often associated with colonization and biofilm formation. Although lipoteichoic acid (LTA) is involved in biofilm formation, the specific role of LTA is not clearly understood. In this study, we demonstrated that LTA released from Lactobacillus plantarum could inhibit S...
2018: Frontiers in Microbiology
Mingming Pu, Lili Sheng, Sooyeon Song, Ting Gong, Thomas K Wood
Pseudomonas aeruginosa causes many biofilm infections, and the rugose small-colony variants (RSCVs) of this bacterium are important for infection. We found here that inactivation of PA2444, which we determined to be a serine hydroxymethyltransferase (SHMT), leads to the RSCV phenotype of P. aeruginosa PA14. In addition, loss of PA2444 increases biofilm formation by two orders of magnitude, increases exopolysaccharide by 45-fold, and abolishes swarming. The RSCV phenotype is related to higher cyclic diguanylate concentrations due to increased activity of the Wsp chemosensory system, including diguanylate cyclase WspR...
2018: Frontiers in Microbiology
S P Rout, L Payne, S Walker, T Scott, P Heard, H Eccles, G Bond, P Shah, P Bills, B R Jackson, S A Boxall, A P Laws, C Charles, S J Williams, P N Humphreys
14 C is an important consideration within safety assessments for proposed geological disposal facilities for radioactive wastes, since it is capable of re-entering the biosphere through the generation of14 C bearing gases. The irradiation of graphite moderators in the UK gas-cooled nuclear power stations has led to the generation of a significant volume of14 C-containing intermediate level wastes. Some of this14 C is present as a carbonaceous deposit on channel wall surfaces. Within this study, the potential of biofilm growth upon irradiated and13 C doped graphite at alkaline pH was investigated...
March 13, 2018: Scientific Reports
Celia Munck, Elsa Thierry, Sarah Gräßle, Si Hui Chen, Adeline Su Yien Ting
The isolate Coriolopsis sp. (1c3) was cultured on muslin cloth to induce formation of filamentous biofilm. The biofilm and the free-mycelium forms (control) were then used to treat two triphenylmethane dyes; Cotton Blue (CB) and Crystal Violet (CV). The biofilm comprised primarily of a compact mass of mycelium while sparse mycelium network was detected in free-mycelium forms. Results revealed significant decolourization activities by filamentous biofilm of 1c3 for CB (79.6%) and CV (85.1%), compared to free-mycelium forms (72...
March 10, 2018: Journal of Environmental Management
Amo Dal Piva, Lpc Contreras, F C Ribeiro, L C Anami, Sea Camargo, Aoc Jorge, M A Bottino
INTRODUCTION: This study evaluated the morphology, biofilm formation, and viability of human gingival fibroblasts in contact with two monolithic ceramics after two different finishing techniques: polishing or glazing. For this, 92 blocks (4.5 × 4.5 × 1.5 mm) of each ceramic were made using high translucency zirconia partially stabilized by yttrium (YZHT) and lithium silicate reinforced by zirconium (ZLS). METHODS AND MATERIALS: Blocks were sintered and then divided into glazing (g) or polishing (p) surface finish...
March 13, 2018: Operative Dentistry
Yu Cao, Hualiang Pi, Pete Chandrangsu, Yongtao Li, Yuqi Wang, Han Zhou, Hanqin Xiong, John D Helmann, Yanfei Cai
Plant growth promoting rhizobacteria (PGPR) provide an effective and environmentally sustainable method to protect crops against pathogens. The spore-forming Bacilli are attractive PGPR due to their ease of storage and application. Here, we characterized two rhizosphere-associated Bacillus velezensis isolates (Y6 and F7) that possess strong antagonistic activity against Ralstonia solanacearum and Fusarium oxysporum under both laboratory and greenhouse conditions. We identified three lipopeptide (LP) compounds (surfactin, iturin and fengycin) as responsible for the antimicrobial activity of these two strains...
March 12, 2018: Scientific Reports
Anne Diehl, Yvette Roske, Linda Ball, Anup Chowdhury, Matthias Hiller, Noel Molière, Regina Kramer, Daniel Stöppler, Catherine L Worth, Brigitte Schlegel, Martina Leidert, Nils Cremer, Natalja Erdmann, Daniel Lopez, Heike Stephanowitz, Eberhard Krause, Barth-Jan van Rossum, Peter Schmieder, Udo Heinemann, Kürşad Turgay, Ümit Akbey, Hartmut Oschkinat
Microorganisms form surface-attached communities, termed biofilms, which can serve as protection against host immune reactions or antibiotics. Bacillus subtilis biofilms contain TasA as major proteinaceous component in addition to exopolysaccharides. In stark contrast to the initially unfolded biofilm proteins of other bacteria, TasA is a soluble, stably folded monomer, whose structure we have determined by X-ray crystallography. Subsequently, we characterized in vitro different oligomeric forms of TasA by NMR, EM, X-ray diffraction, and analytical ultracentrifugation (AUC) experiments...
March 12, 2018: Proceedings of the National Academy of Sciences of the United States of America
(no author information available yet)
Chris S Earl, Teh Wooi Keong, Shi-qi An, Sarah Murdoch, Yvonne McCarthy, Junkal Garmendia, Joseph Ward, J Maxwell Dow, Liang Yang, George A O'Toole & Robert P RyanThe above article, published May 20 2015 in EMBO Molecular Medicine , has been retracted by agreement between the authors of the study, CSE, TWK, SQA, SM, YMcC, JG, JW, JMD, LY, RPR, the journal Chief Editor and the EMBO Head of Scientific Publications in accordance with the outcomes of independent investigations conducted by the University of Dundee and University College Cork...
March 12, 2018: EMBO Molecular Medicine
Alvaro Orell, Vanessa Tripp, Victor Aliaga-Tobar, Sonja-Verena Albers, Vinicius Maracaja-Coutinho, Lennart Randau
Non-coding RNAs (ncRNA) are involved in essential biological processes in all three domains of life. The regulatory potential of ncRNAs in Archaea is, however, not fully explored. In this study, RNA-seq analyses identified a set of 29 ncRNA transcripts in the hyperthermophilic archaeon Sulfolobus acidocaldarius that were differentially expressed in response to biofilm formation. The most abundant ncRNA of this set was found to be resistant to RNase R treatment (RNase R resistant RNA, RrrR(+)) due to duplex formation with a reverse complementary RNA (RrrR(-))...
February 26, 2018: Nucleic Acids Research
Syed Hidayathulla, Abdelaaty A Shahat, Mansour S Alsaid, Abdullah A Al-Mishari
The present study investigates the optimization of tannase production from A. nidulans for various physicochemical parameters and harvests tannase for its chemical characterization. The maximum tannase activity was observed on the third day of incubation at 35°C and the stability was observed at pH 5.5 to 6.0 by holding its 100% activity. The tannase was partially purified from A. nidulans [FT10] by ammonium sulfate precipitation at different concentrations and it was found that at 80% of ammonium sulfate concentration, the precipitate exhibited the maximum activity for tannase of 96 U/ml...
February 26, 2018: FEMS Microbiology Letters
Brintha Parasumanna Girinathan, Junjun Ou, Bruno Dupuy, Revathi Govind
Clostridium difficile is the primary cause of nosocomial diarrhea and pseudomembranous colitis. It produces dormant spores, which serve as an infectious vehicle responsible for transmission of the disease and persistence of the organism in the environment. In Bacillus subtilis, the sin locus coding SinR (113 aa) and SinI (57 aa) is responsible for sporulation inhibition. In B. subtilis, SinR mainly acts as a repressor of its target genes to control sporulation, biofilm formation, and autolysis. SinI is an inhibitor of SinR, so their interaction determines whether SinR can inhibit its target gene expression...
March 12, 2018: PLoS Pathogens
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