Read by QxMD icon Read


Xiaobei Wang, Huaixu Cheng, Mingsheng Lu, Yaowei Fang, Yuliang Jiao, Weijuan Li, Gengmao Zhao, Shujun Wang
Dental plaque is a biofilm of water-soluble and water-insoluble polysaccharides, produced primarily by Streptococcus mutans. Dextranase can inhibit biofilm formation. Here, a dextranase gene from the marine microorganism Arthrobacter oxydans KQ11-1 is described, and cloned and expressed using E. coli DH5α competent cells. The recombinant enzyme was then purified and its properties were characterized. The optimal temperature and pH were determined to be 60°C and 6.5, respectively. High-performance liquid chromatography data show that the final hydrolysis products were glucose, maltose, maltotriose, and maltotetraose...
November 2016: Biofouling
J Travis Hunsucker, Kelli Z Hunsucker, Harrison Gardner, Geoffrey Swain
The role of hydrodynamic wall shear stresses on the development of the fouling community structure and resulting frictional drag were examined using a commercially available fouling release coating. Immersed test panels were exposed to three different hydrodynamic treatments, one static and two dynamic (corresponding to an estimated wall shear stress of 7.0  and 25.5 Pa). The drag of the panels was measured in a hydrodynamic test chamber at discrete time intervals over 35 days. The fouling community composition on the static panels was significantly different from the organisms observed on the dynamic panels...
November 2016: Biofouling
Carlos Silva, Bruno Nunes, António Ja Nogueira, Fernando Gonçalves, Joana L Pereira
Using the bivalve macrofouler Corbicula fluminea, the suitability of in vitro testing as a stepping stone towards the improvement of control methods based on chemical mixtures was addressed in this study. In vitro cholinesterase (ChE) activity inhibition following single exposure of C. fluminea tissue to four model chemicals (the organophosphates dimethoate and dichlorvos, copper and sodium dodecyl phosphate [SDS]) was first assessed. Consequently, mixtures of dimethoate with copper and dichlorvos with SDS were tested and modelled; mixtures with ChE revealed synergistic interactions for both chemical pairs...
November 2016: Biofouling
Sergio García, Alfredo Trueba, Luis M Vega, Ernesto Madariaga
The present study evaluated biofilm growth in AISI 316L stainless steel tubes for seawater-cooled exchanger-condensers that had four different arithmetic mean surface roughness values ranging from 0.14 μm to 1.2 μm. The results of fluid frictional resistance and heat transfer resistance regarding biofilm formation in the roughest surface showed increases of 28.2% and 19.1% respectively, compared with the smoothest surface. The biofilm thickness taken at the end of the experiment showed variations of up to 74% between the smoothest and roughest surfaces...
November 2016: Biofouling
Kannan Rama Devi, Ramanathan Srinivasan, Arunachalam Kannappan, Sivasubramanian Santhakumari, Murugan Bhuvaneswari, Periyannan Rajasekar, Narayanan Marimuthu Prabhu, Arumugam Veera Ravi
Rosmarinic acid (RA) was assessed for its quorum sensing inhibitory (QSI) potential against Aeromonas hydrophila strains AH 1, AH 12 and MTCC 1739. The pathogenic strains of A. hydrophila were isolated from infected zebrafish and identified through biochemical analysis and amplification of a species-specific gene (rpsL). The biofilm inhibitory concentration (BIC) of RA against A. hydrophila strains was found to be 750 μg ml(-1). At this concentration, RA reduced the QS mediated hemolysin, lipase and elastase production in A...
November 2016: Biofouling
Caitlin L Bojanowski, Wendy J Crookes-Goodson, Jayne B Robinson
In the present study, the use of bacteriophages to prevent growth and/or biofouling by Pseudomonas aeruginosa PAO1 was investigated in microcosms containing Jet A aviation fuel as the carbon source. Bacteriophages were found to be effective at preventing biofilm formation but did not always prevent planktonic growth in the microcosms. This result was at odds with experiments conducted in nutrient-rich medium, demonstrating the necessity to test antimicrobial and antifouling strategies under conditions as near as possible to the 'real world'...
November 2016: Biofouling
A R Markande, A S Nerurkar
A novel estuarine bacterial strain, Solibacillus silvestris AM1, produces an extracellular, thermostable and fibrous, glycoprotein bioemulsifier (BE-AM1). The amyloid nature of the bioemulsifier (BE-AM1) was confirmed by biophysical techniques (Congo red based polarization microscopy, ThioflavinS based fluorescent microscopy, fibrous arrangement in transmission electron microscopy and secondary structure measurement by FTIR and CD spectrum analysis). Cell-bound BE-AM1 production by S. silvestris AM1 during the mid-logarithmic phase of growth coincided with a decrease in cell surface hydrophobicity, and an increase in cell autoaggregation and biofilm formation...
November 2016: Biofouling
Dorji Dorji, Ross M Graham, Peter Richmond, Anthony Keil, Trilochan K Mukkur
Whooping cough caused by Bordetella pertussis is increasing in several countries despite high vaccine coverage. One potential reason for the resurgence is the emergence of genetic variants of the bacterium. Biofilm formation has recently been associated with the pathogenesis of B. pertussis. Biofilm formation of 21 Western Australian B. pertussis clinical isolates was investigated. All isolates formed thicker biofilms than the reference vaccine strain Tohama I while retaining susceptibility to ampicillin, erythromycin, azithromycin and streptomycin...
October 2016: Biofouling
Hassan Younas, Yuhuan Fei, Jiahui Shao, Yiliang He
Biofouling produces concentrated microbial populations with highly resistive biofilms and is considered to be a serious obstacle for a wide range of membrane technology applications. An antibacterial super-hydrophilic barrier could help to reduce biofouling by preventing direct contact between membranes and bacteria. In this study, an antibacterial super-hydrophilic barrier consisting of a layer of TiO2 nanoparticles (NPs) was developed on polyvinylidene fluoride (PVDF)-based membrane via a facile technique...
October 2016: Biofouling
Rudolph E Sloup, Roberto J Cieza, David B Needle, Robert B Abramovitch, Alfredo G Torres, Christopher M Waters
Escherichia coli biotype O104:H4 recently caused the deadliest E. coli outbreak ever reported. Based on prior results, it was hypothesized that compounds inhibiting biofilm formation by O104:H4 would reduce its pathogenesis. The nonionic surfactants polysorbate 80 (PS80) and polysorbate 20 (PS20) were found to reduce biofilms by ≥ 90% at submicromolar concentrations and elicited nearly complete dispersal of preformed biofilms. PS80 did not significantly impact in vivo colonization in a mouse infection model; however, mice treated with PS80 exhibited almost no intestinal inflammation or tissue damage while untreated mice exhibited robust pathology...
October 2016: Biofouling
Marcelo Rodrigues, Thomas Ostermann, Leopold Kremeser, Herbert Lindner, Christian Beisel, Eugene Berezikov, Bert Hobmayer, Peter Ladurner
The differentiated ectodermal basal disc cells of the freshwater cnidarian Hydra secrete proteinaceous glue to temporarily attach themselves to underwater surfaces. Using transcriptome sequencing and a basal disc-specific RNA-seq combined with in situ hybridisation a highly specific set of candidate adhesive genes was identified. A de novo transcriptome assembly of 55,849 transcripts (>200 bp) was generated using paired-end and single reads from Illumina libraries constructed from different polyp conditions...
October 2016: Biofouling
James John, Rajagopalan Saranathan, Lakshmi Narayana Adigopula, Vasanth Thamodharan, Satya Prakash Singh, T Pragna Lakshmi, Mallu Abhiram CharanTej, R Srinivasa Rao, R Krishna, H Surya Prakash Rao, K Prashanth
Secretory N-acyl homoserine lactones (AHLs) mediate quorum sensing (QS) in bacteria. AHLs are shown to be inhibitory for an unrelated group of bacteria and might mimic host signalling elements, thereby subverting the regulatory events in host cells. This study investigated the AHL produced by Acinetobacter baumannii and analysed its effect on other bacterial species and mammalian cells. Chemically characterized AHL had an m/z value of 325 with a molecular formula C18H31NO4 and showed its inhibitory potential against Staphylococcus aureus...
October 2016: Biofouling
Ana Cristina Abreu, Maria José Saavedra, Lúcia C Simões, Manuel Simões
Combinations of selected phytochemicals (reserpine, pyrrolidine, quinine, morin and quercetin) with antibiotics (ciprofloxacin, tetracycline and erythromycin) were tested on the prevention and control of Staphylococcus aureus biofilms. The phytochemicals were also studied for their ability to avoid antibiotic adaptation and to inhibit antibiotic efflux pumps. Morin, pyrrolidine and quercetin at subinhibitory concentrations had significant effects in biofilm prevention and/or control when applied alone and combined with antibiotics...
October 2016: Biofouling
Ji-Eun Jung, Jian-Na Cai, Sung-Dae Cho, Kwang-Yeob Song, Jae-Gyu Jeon
Despite the widespread use of fluoride for the prevention of dental caries, few studies have demonstrated the effects of fluoride on the bacterial composition of dental biofilms. This study investigated whether fluoride affects the proportion of Streptococcus mutans and S. oralis in mono- and dual-species biofilm models, via microbiological, biochemical, and confocal fluorescence microscope studies. Fluoride did not affect the bacterial count and bio-volume of S. mutans and S. oralis in mono-species biofilms, except for the 24-h-old S...
October 2016: Biofouling
E M Galván, C Mateyca, L Ielpi
Most catheter-associated urinary tract infections are polymicrobial. Here, uropathogen interactions in dual-species biofilms were studied. The dual-species associations selected based on their prevalence in clinical settings were Klebsiella pneumoniae-Escherichia coli, E. coli-Enterococcus faecalis, K. pneumoniae-E. faecalis, and K. pneumoniae-Proteus mirabilis. All species developed single-species biofilms in artificial urine. The ability of K. pneumoniae to form biofilms was not affected by E. coli or E. faecalis co-inoculation, but was impaired by P...
October 2016: Biofouling
A C S Ré, M P Ferreira, O Freitas, C P Aires
The effect of a drug-delivery system containing antibacterial metronidazole (MDZ) prescribed for periodontitis on supragingival biofilm was evaluated, and possible interference by this biofilm in the drug release profile was investigated. Streptococcus mutans biofilms were grown and exposed to a controlled-release formulation of MDZ or the same formulation without MDZ (vehicle control). Untreated biofilms were used as a negative control (NC). Biofilms and culture medium (containing detached cells) were collected 24, 48, 72, and 96 h after first exposure to treatments...
October 2016: Biofouling
Shinjiro Ushiama, James A Smith, Iain M Suthers, Michael Lowry, Emma L Johnston
Artificial reefs provide shelter and can be an important source of food for fish depending on the epibenthic community on the structure. The growth and diversity of this community is influenced by the substratum material and the surface orientation of the reef. Settlement plates of four materials (Perspex, sandstone, wood and steel) were deployed in three orientations (upwards, downwards and vertical) at a depth of 33 m on a designed artificial reef (DAR) off the coast of Sydney, Australia. After three months, the steel surfaces had lower invertebrate species richness, total abundance and diversity compared to other surfaces...
October 2016: Biofouling
Phanindhar Shivapooja, Changyong Cao, Beatriz Orihuela, Vrad Levering, Xuanhe Zhao, Daniel Rittschof, Gabriel P López
Silicone-oil additives are often used in fouling-release silicone coatings to reduce the adhesion strength of barnacles and other biofouling organisms. This study follows on from a recently reported active approach to detach barnacles, which was based on the surface strain of elastomeric materials, by investigating a new, dual-action approach to barnacle detachment using Ecoflex®-based elastomers incorporated with poly(dimethylsiloxane)-based oil additives. The experimental results support the hypothesis that silicone-oil additives reduce the amount of substratum strain required to detach barnacles...
October 2016: Biofouling
J Malheiro, I Gomes, A Borges, M M S M Bastos, J-Y Maillard, F Borges, M Simões
The indiscriminate use of biocides for general disinfection has contributed to the increased incidence of antimicrobial tolerant microorganisms. This study aims to assess the potential of seven phytochemicals (tyrosol, caffeic acid, ferulic acid, cinnamaldehyde, coumaric acid, cinnamic acid and eugenol) in the control of planktonic and sessile cells of Staphylococcus aureus and Escherichia coli. Cinnamaldehyde and eugenol showed antimicrobial properties, minimum inhibitory concentrations of 3-5 and 5-12 mM and minimum bactericidal concentrations of 10-12 and 10-14 mM against S...
October 2016: Biofouling
Paula Fernanda Kreling, Kelly Limi Aida, Loiane Massunari, Karina Sampaio Caiaffa, Célio Percinoto, Telma Blanca Lombardo Bedran, Denise Madalena Palomari Spolidorio, Gabriel Flores Abuna, Eduardo Maffud Cilli, Cristiane Duque
This study evaluated the cytotoxicity and effect of fragments derived from three oral cationic peptides (CP): LL-37, D6-17 and D1-23 against cariogenic bacteria under planktonic and biofilm conditions. For cytotoxicity analysis, two epithelial cell lines were used. The minimum inhibitory concentration and the minimal bactericidal concentration were determined for the CP fragments and the control (chlorhexidine-CHX) against cariogenic bacteria. The fractional inhibitory concentration was obtained for the combinations of CP fragments on Streptococcus mutans...
October 2016: Biofouling
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"