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bacteria biofilm

H Zha, A Jeffs, Y Dong, G Lewis
Tail fan necrosis (TFN) is a common condition found in commercially exploited spiny lobsters that greatly diminishes their commercial value. Bacteria possessing proteolytic, chitinolytic and lipolytic capabilities were associated with TFN in spiny lobsters, Jasus edwardsii. In this study, 69 bacterial isolates exhibiting all the three enzymatic capabilities from the haemolymph and tail fans of J. edwardsii with and without TFN were further characterized and compared, including morphology, biofilm formation, antimicrobial activity, antimicrobial resistance, and production of siderophores, melanin and ammonia...
February 23, 2018: Journal of Fish Diseases
Anna M Duraj-Thatte, Pichet Praveschotinunt, Trevor R Nash, Frederick R Ward, Neel S Joshi
Extracellular appendages play a significant role in mediating communication between bacteria and their host. Curli fibers are a class of bacterial fimbria that is highly amenable to engineering. We demonstrate the use of engineered curli fibers to rationally program interactions between bacteria and components of the mucosal epithelium. Commensal E. coli strains were engineered to produce recombinant curli fibers fused to the trefoil family of human cytokines. Biofilms formed from these strains bound more mucins than those producing wild-type curli fibers, and modulated mucin rheology as well...
February 22, 2018: Scientific Reports
Yancheng Li, Yingmu Wang, Ziyuan Lin, Jiale Wang, Qiang He, Jian Zhou
Pulping wastewater still contains massive refractory organics after biotreatment, with high colority, low biodegradability, and lasting biotoxicity. To eliminate refractory organics in pulping wastewater, a methanotrophic co-metabolic system in a gas cycle Sequencing Batch Biofilm Reactor (gcSBBR) seeded by soil at a ventilation opening of coal mine was quickly built on the 92nd day. The removal rate of COD, colority and TOC was 53.28%, 50.59% and 51.60%, respectively. Analysis of 3D-EEM indicated that glycolated protein-like, melanoidin-like or lignocellulose-like, and humic acid-like decreased by 7...
February 13, 2018: Bioresource Technology
Shuai Zhao, Pu Liu, Yongyan Niu, Zhengjun Chen, Aman Khan, Pengyun Zhang, Xiangkai Li
Hexavalent chromium (Cr(VI)) is a well-known toxic heavy metal in industrial wastewater, but in situ and real time monitoring cannot be achieved by current methods used during industrial wastewater treatment processes. In this study, a Sediment Microbial Fuel Cell (SMFC) was used as a biosensor for in situ real-time monitoring of Cr(VI), which was the organic substrate is oxidized in the anode and Cr(VI) is reduced at the cathode simultaneously. The pH 6.4 and temperature 25 °C were optimal conditions for the operation...
February 22, 2018: Sensors
Jan Hynek, Jaroslav Zelenka, Jiri Rathousky, Pavel Kubát, Tomáš Ruml, Jan Demel, Kamil Lang
Microbial colonization of biomedical devices is a recognized complication contributing to healthcare-associated infections. One of the possible approaches to prevent surfaces from the biofilm formation is antimicrobial photodynamic inactivation, based on the cytotoxic effect of singlet oxygen, O2 (1 Δg ), a short-lived, highly oxidative species, produced by energy transfer between excited photosensitizers and molecular oxygen. We synthesized porphyrin-based covalent organic frameworks (COFs) by the Schiff-base chemistry...
February 22, 2018: ACS Applied Materials & Interfaces
Minkyu Choi, Kyungjin Cho, Dawoon Jeong, Yun-Chul Chung, Joonhong Park, Seockheon Lee, Hyokwan Bae
In this study, the effects of the ammonium loading rate (ALR) and inorganic carbon loading rate (ILR) on the nitrification performance and composition of a nitrifying bacterial community were investigated in a moving bed biofilm reactor, using poly(vinyl alcohol) (PVA) sponge cubes as a supporting carrier. Between the two ALRs of 0.36 and 2.16 kg-N m-1 d-1 , stable partial nitritation was achieved at the higher ALR. Inorganic carbon was dosed at high levels: 33.1, 22.0, 16.4, 11.0, and 5.4 times the theoretical amount...
February 22, 2018: Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances & Environmental Engineering
Yow-Ren Chang, Eric R Weeks, William A Ducker
We demonstrate that the surface motility of the bacterium, Pseudomonas aeruginosa, is hindered by a crystalline hemispherical topography with wavelength in the range 2-8 µm. The motility was determined by analysis of time-lapse microscopy images of cells in flowing growth medium maintained at 37°C. The net displacement of bacteria over 5 minutes is much lower on surfaces containing 2-8 µm hemispheres than on flat topography, but displacement on the 1 µm hemispheres is not lower. That is, there is a threshold between 1 µm and 2 µm for response to the topography...
February 22, 2018: ACS Applied Materials & Interfaces
Casey P Peterson, Cassidy Sauer, Christa H Chatfield
Human infection by bacteria of the genus Legionella most often result in the pneumonia known as Legionnaires Disease. Legionella is found as a resident of adherent biofilms in man-made water systems. Disinfection efforts to prevent Legionella infections require a better understanding of the structures that promote Legionella surface attachment and biofilm colonization. Various enzymatic treatments, including multiple carbohydrate-targeting mixtures, failed to disrupt Legionella biofilms, despite the presence of carbohydrates in the biofilms as shown by biochemical methods and concanavalin-A lectin staining...
February 21, 2018: Current Microbiology
Kirby R Lattwein, Himanshu Shekhar, Willem J B van Wamel, Tammy Gonzalez, Andrew B Herr, Christy K Holland, Klazina Kooiman
Infective endocarditis (IE) is associated with high morbidity and mortality rates. The predominant bacteria causing IE is Staphylococcus aureus (S. aureus), which can bind to existing thrombi on heart valves and generate vegetations (biofilms). In this in vitro flow study, we evaluated sonobactericide as a novel strategy to treat IE, using ultrasound and an ultrasound contrast agent with or without other therapeutics. We developed a model of IE biofilm using human whole-blood clots infected with patient-derived S...
February 21, 2018: Scientific Reports
Heidi B Kaplan, Justin A Miranda, Gloria R Gogola, Karen Gomez, Catherine G Ambrose
Polymerase chain reaction (PCR) has been proposed as a method to identify bacteria in clinical samples because it is more sensitive than culture techniques and can produce results rapidly. However, PCR can detect DNA from dead cells and thus cannot distinguish between live and dead cells in a tissue sample. Killed Staphylococcus aureus cells were implanted into the femurs and knee joints of rats to determine the length of time that DNA from dead cells is detectable in a living animal under conditions similar to common orthopedic infections...
February 2, 2018: Diagnostic Microbiology and Infectious Disease
Andrew B Dippel, Wyatt A Anderson, Robert S Evans, Samuel Deutsch, Ming C Hammond
Bacteria colonize highly diverse and complex environments, from gastrointestinal tracts, to soil and plant surfaces. This colonization process is controlled in part by the intracellular signal cyclic di-GMP, which regulates bacterial motility and biofilm formation. To interrogate cyclic di-GMP signaling networks, a variety of fluorescent biosensors for live cell imaging of cyclic di-GMP have been developed. However, the need for external illumination precludes the use of these tools for imaging bacteria in their natural environments, including in deep tissues of whole organisms and in samples that are highly autofluorescent or photosensitive...
February 21, 2018: ACS Chemical Biology
Mauricio Díaz, Matias Castro, Sylvia Copaja, Nicolas Guiliani
Acidophile bacteria belonging to the Acidithiobacillus genus are pivotal players for the bioleaching of metallic values such as copper. Cell adherence to ores and biofilm formation, mediated by the production of extracellular polymeric substances, strongly favors bioleaching activity. In recent years, the second messenger cyclic diguanylate (c-di-GMP) has emerged as a central regulator for biofilm formation in bacteria. C-di-GMP pathways have been reported in different Acidithiobacillus species; however, c-di-GMP effectors and signal transduction networks are still largely uncharacterized in these extremophile species...
February 21, 2018: Genes
Alfonso Alejo-Armijo, Nicolás Glibota, María P Frías, Joaquín Altarejos, Antonio Gálvez, Sofía Salido, Elena Ortega-Morente
Natural A-type procyanidins have shown very interesting biological activities, such as their proven antiadherence properties against pathogenic bacteria. In order to find the structural features responsible for their activities, we describe herein the design and synthesis of six A-type procyanidin analogues and the evaluation of their antimicrobial and antibiofilm properties against 12 resistant bacteria, both Gram positive and Gram negative, isolated from organic foods. The natural A-type procyanidin A-2, which had known antiadherence activity, was also tested as a reference compound for the comparative studies...
February 21, 2018: Journal of Agricultural and Food Chemistry
Kayley H Janssen, Manisha R Diaz, Matthew Golden, Justin W Graham, Wes Sanders, Matthew C Wolfgang, Timothy L Yahr
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen with distinct acute and chronic virulence phenotypes. Whereas acute virulence is typically associated with expression of a type III secretion system (T3SS), chronic virulence is characterized by biofilm formation. Many of the phenotypes associated with acute and chronic virulence are inversely regulated by RsmA and RsmF. RsmA and RsmF are both members of the CsrA family of RNA-binding proteins and regulate protein synthesis at the post-transcriptional level...
February 20, 2018: Journal of Bacteriology
M V Sheraton, K H Yam, C H Tan, H S Oh, E Mancini, L Yang, S A Rice, P M A Sloot
Segregation of bacteria based on their metabolic activity in biofilms plays an important role in the development of antibiotic drug resistance. Mushroom-shaped biofilm structures, which are reported for many bacteria, exhibit topographically varying levels of multiple drug resistance from the cap of the mushroom to its stalk. Understanding the dynamics behind the formation of such structures can aid in design of drug delivery systems, antibiotics, or physical systems for removal of biofilms. We explore the development of metabolically heterogenous Pseudomonas aeruginosa biofilms using numerical models and laboratory knock-out experiments on wild-type and chemotaxis deficient mutants...
February 20, 2018: Antimicrobial Agents and Chemotherapy
Supeng Yin, Bei Jiang, Guangtao Huang, Yulong Zhang, Bo You, Yu Chen, Yali Gong, Jing Chen, Zhiqiang Yuan, Yan Zhao, Ming Li, Fuquan Hu, Zichen Yang, Yizhi Peng
BACKGROUND/AIMS: N-acetylcysteine (NAC) is a novel and promising agent with activity against bacterial biofilms. Human serum also inhibits biofilm formation by some bacteria. We tested whether the combination of NAC and human serum offers greater anti-biofilm activity than either agent alone. METHODS: Microtiter plate assays and confocal laser scanning microscopy were used to evaluate bacterial biofilm formation in the presence of NAC and human serum. qPCR was used to examine expression of selected biofilm-associated genes...
February 15, 2018: Cellular Physiology and Biochemistry
Anke Stüken, Thomas H A Haverkamp, Hubert A A M Dirven, Gregor D Gilfillan, Magnus Leithaug, Vidar Lund
Copper-silver-ionization (CSI) is an in-house water disinfection method primarily installed to eradicate Legionella bacteria from drinking water distribution systems (DWDS). Its effect on the abundance of culturable Legionella and Legionella infections has been documented in several studies. However, the effect of CSI on other bacteria in DWDS is largely unknown. To investigate these effects, we characterised drinking water and biofilm communities in a hospital using CSI, in a neighbouring building without CSI, and in treated drinking water at the local water treatment plant...
February 20, 2018: Environmental Science & Technology
Angela Casillo, Rosa Lanzetta, Michelangelo Parrilli, Maria Michela Corsaro
The marine environment is the largest aquatic ecosystem on Earth and it harbours microorganisms responsible for more than 50% of total biomass of prokaryotes in the world. All these microorganisms produce extracellular polymers that constitute a substantial part of the dissolved organic carbon, often in the form of exopolysaccharides (EPS). In addition, the production of these polymers is often correlated to the establishment of the biofilm growth mode, during which they are important matrix components. Their functions include adhesion and colonization of surfaces, protection of the bacterial cells and support for biochemical interactions between the bacteria and the surrounding environment...
February 20, 2018: Marine Drugs
F Carinci, L Scapoli, M Contaldo, R Santoro, A Palmieri, F Pezzetti, D Lauritano, V Candotto, D Mucchi, L Baggi, A Tagliabue, L Tettamanti
Legionella spp. are ubiquitous in aquatic habitats and water distribution systems, including dental unit waterlines. Surveys have shown that the percentage of samples taken at different dental sites that were positive for Legionella spp. were highly variable and ranged from 0% to 100%. Cultivation is the principal approach to evaluating bacterial contamination employed in the past, but applying this approach to testing for Legionella spp. may result in false-negative data or underestimated bacterial counts...
January 2018: Journal of Biological Regulators and Homeostatic Agents
Muhammad Usman Farid, Sanghyun Jeong, Dong Han Seo, Rafay Ahmed, Condon Lau, Nirmal Kumar Gali, Zhi Ning, Alicia Kyoungjin An
While the cytotoxicity of graphene oxide (GO) has been well established, its bactericidal mechanism, however, has yet to be elucidated to advance GO-based biomedical and environmental applications. In an attempt to better understand the bactericidal action of GO, herein we studied the interactions of GO with Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus cells using physical techniques and chemical probes, respectively. In particular, a novel laser-induced breakdown spectroscopy (LIBS) based elemental fingerprint analysis revealed notable differences between viable and non-viable cells based on the difference in the concentration of trace inorganic elements in complex bacterial systems, which reflect cellular membrane integrity...
February 20, 2018: Nanoscale
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