scholarly journals The expression and characterization of recombinant cp19k barnacle cement protein from Pollicipes pollicipes

2019 ◽  
Vol 374 (1784) ◽  
pp. 20190205 ◽  
Author(s):  
Maura A. Tilbury ◽  
Sean McCarthy ◽  
Magdalena Domagalska ◽  
Thomas Ederth ◽  
Anne Marie Power ◽  
...  
Keyword(s):  
Trigger Factor ◽  
Surface Coat ◽  
Adhesive Properties ◽  
E Coli ◽  
Assembled Monolayers ◽  
Pollicipes Pollicipes ◽  
Low Levels ◽  
Adhesive Proteins ◽  
Cement Protein ◽  
Barnacle Cement

Adhesive proteins of barnacle cement have potential as environmentally friendly adhesives owing to their ability to adhere to various substrates in aqueous environments. By understanding the taxonomic breath of barnacles with different lifestyles, we may uncover commonalities in adhesives produced by these specialized organisms. The 19 kDa cement protein (cp19k) of the stalked barnacle Pollicipes pollicipes was expressed in Escherichia coli BL21 to investigate its adhesive properties. Initial expression of hexahistidine-tagged protein (rPpolcp19k-his) yielded low levels of insoluble protein. Co-overproduction of E. coli molecular chaperones GroEL-GroES and trigger factor (TF) increased soluble protein yields, although TF co-purified with the target protein (TF-rPpolcp19k-his). Surface coat analysis revealed high levels of adsorption of the TF-rPpolcp19k-his complex and of purified E. coli TF on both hydrophobic and hydrophilic surfaces, while low levels of adsorption were observed for rPpolcp19k-his. Tag-free rPpolcp19k protein also exhibited low adsorption compared to fibrinogen and Cell-Tak controls on hydrophobic, neutral hydrophilic and charged self-assembled monolayers under surface plasmon resonance assay conditions designed to mimic the barnacle cement gland or seawater. Because rPpolcp19k protein displays low adhesive capability, this protein is suggested to confer the ability to self-assemble into a plaque within the barnacle cement complex. This article is part of the theme issue ‘Transdisciplinary approaches to the study of adhesion and adhesives in biological systems’.

scholarly journals Heteropolysaccharides from S. cerevisiae show anti-adhesive properties against E. coli associated with Crohn’s disease

2021 ◽  
pp. 118415
Author(s):  
Adeline Sivignon ◽  
Shin-Yi Yu ◽  
Nathalie Ballet ◽  
Pascal Vandekerckove ◽  
Nicolas Barnich ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Adhesive Properties ◽  
E Coli

scholarly journals Escherichia coli Contamination of Vegetables Grown in Soils Fertilized with Noncomposted Bovine Manure: Garden-Scale Studies

2004 ◽  
Vol 70 (11) ◽  
pp. 6420-6427 ◽  
Author(s):  
Steven C. Ingham ◽  
Jill A. Losinski ◽  
Matthew P. Andrews ◽  
Jane E. Breuer ◽  
Jeffry R. Breuer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tap Water ◽  
Silty Clay ◽  
Silt Loam ◽  
Silty Clay Loam ◽  
Manure Application ◽  
E Coli ◽  
Fertilized Soil ◽  
Low Levels ◽  
National Organic Program

ABSTRACT In this study we tested the validity of the National Organic Program (NOP) requirement for a ≥120-day interval between application of noncomposted manure and harvesting of vegetables grown in manure-fertilized soil. Noncomposted bovine manure was applied to 9.3-m2 plots at three Wisconsin sites (loamy sand, silt loam, and silty clay loam) prior to spring and summer planting of carrots, radishes, and lettuce. Soil and washed (30 s under running tap water) vegetables were analyzed for indigenous Escherichia coli. Within 90 days, the level of E. coli in manure-fertilized soil generally decreased by about 3 log CFU/g from initial levels of 4.2 to 4.4 log CFU/g. Low levels of E. coli generally persisted in manure-fertilized soil for more than 100 days and were detected in enriched soil from all three sites 132 to 168 days after manure application. For carrots and lettuce, at least one enrichment-negative sample was obtained ≤100 days after manure application for 63 and 88% of the treatments, respectively. The current ≥120-day limit provided an even greater likelihood of not detecting E. coli on carrots (≥1 enrichment-negative result for 100% of the treatments). The rapid maturation of radishes prevented conclusive evaluation of a 100- or 120-day application-to-harvest interval. The absolute absence of E. coli from vegetables harvested from manure-fertilized Wisconsin soils may not be ensured solely by adherence to the NOP ≥120-day limit. Unless pathogens are far better at colonizing vegetables than indigenous E. coli strains are, it appears that the risk of contamination for vegetables grown in Wisconsin soils would be elevated only slightly by reducing the NOP requirement to ≥100 days.

scholarly journals Mechanically Ventilated Broiler Sheds: a Possible Source of Aerosolized Salmonella, Campylobacter, and Escherichia coli

2009 ◽  
Vol 75 (23) ◽  
pp. 7417-7425 ◽  
Author(s):  
H. N. Chinivasagam ◽  
T. Tran ◽  
L. Maddock ◽  
A. Gale ◽  
P. J. Blackall
Keyword(s):  
Escherichia Coli ◽  
Most Probable Number ◽  
Production Cycle ◽  
Airborne Bacteria ◽  
Probable Number ◽  
Mechanically Ventilated ◽  
The Public ◽  
E Coli ◽  
Poultry Farms ◽  
Low Levels

ABSTRACT This study assessed the levels of two key pathogens, Salmonella and Campylobacter, along with the indicator organism Escherichia coli in aerosols within and outside poultry sheds. The study ranged over a 3-year period on four poultry farms and consisted of six trials across the boiler production cycle of around 55 days. Weekly testing of litter and aerosols was carried out through the cycle. A key point that emerged is that the levels of airborne bacteria are linked to the levels of these bacteria in litter. This hypothesis was demonstrated by E. coli. The typical levels of E. coli in litter were ∼108 CFU g−1 and, as a consequence, were in the range of 102 to 104 CFU m−3 in aerosols, both inside and outside the shed. The external levels were always lower than the internal levels. Salmonella was only present intermittently in litter and at lower levels (103 to 105 most probable number [MPN] g−1) and consequently present only intermittently and at low levels in air inside (range of 0.65 to 4.4 MPN m−3) and once outside (2.3 MPN m−3). The Salmonella serovars isolated in litter were generally also isolated from aerosols and dust, with the Salmonella serovars Chester and Sofia being the dominant serovars across these interfaces. Campylobacter was detected late in the production cycle, in litter at levels of around 107 MPN g−1. Campylobacter was detected only once inside the shed and then at low levels of 2.2 MPN m−3. Thus, the public health risk from these organisms in poultry environments via the aerosol pathway is minimal.

O6-methylguanine-DNA methyltransferase in wild-type and ada mutants of Escherichia coli

1982 ◽  
Vol 152 (1) ◽  
pp. 534-537
Author(s):  
S Mitra ◽  
B C Pal ◽  
R S Foote
Keyword(s):  
Escherichia Coli ◽  
Dna Methyltransferase ◽  
Wild Type ◽  
E Coli ◽  
Methylguanine Dna Methyltransferase ◽  
Synthetic Dna ◽  
In The Wild ◽  
Low Levels ◽  
Enzyme Molecules ◽  
Dna Substrate

O(6)-Methylguanine-DNA methyltransferase is induced in Escherichia coli during growth in low levels of N-methyl-N'-nitro-N-nitrosoguanidine. We have developed a sensitive assay for quantitating low levels of this activity with a synthetic DNA substrate containing 3H-labeled O(6)-methylguanine as the only modified base. Although both wild-type and adaptation-deficient (ada) mutants of E. coli contained low but comparable numbers (from 13 to 60) of the enzyme molecules per cell, adaptation treatment caused a significant increase of the enzyme in the wild type but not in the ada mutants, suggesting that the ada mutation is in a regulatory locus and not in the structural gene for the methyltransferase.

scholarly journals Preparation of Sticky Escherichia coli through Surface Display of an Adhesive Catecholamine Moiety

2013 ◽  
Vol 80 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Joseph P. Park ◽  
Min-Jung Choi ◽  
Se Hun Kim ◽  
Seung Hwan Lee ◽  
Haeshin Lee
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Communication Systems ◽  
Cell Attachment ◽  
Surface Display ◽  
Content Type ◽  
E Coli ◽  
Material Surfaces ◽  
Mussel Adhesive ◽  
Adhesive Proteins

ABSTRACTMussels attach to virtually all types of inorganic and organic surfaces in aqueous environments, and catecholamines composed of 3,4-dihydroxy-l-phenylalanine (DOPA), lysine, and histidine in mussel adhesive proteins play a key role in the robust adhesion. DOPA is an unusual catecholic amino acid, and its side chain is called catechol. In this study, we displayed the adhesive moiety of DOPA-histidine onEscherichia colisurfaces using outer membrane protein W as an anchoring motif for the first time. Localization of catecholamines on the cell surface was confirmed by Western blot and immunofluorescence microscopy. Furthermore, cell-to-cell cohesion (i.e., cellular aggregation) induced by the displayed catecholamine and synthesis of gold nanoparticles on the cell surface support functional display of adhesive catecholamines. The engineeredE. coliexhibited significant adhesion onto various material surfaces, including silica and glass microparticles, gold, titanium, silicon, poly(ethylene terephthalate), poly(urethane), and poly(dimethylsiloxane). The uniqueness of this approach utilizing the engineered stickyE. coliis that no chemistry for cell attachment are necessary, and the ability of spontaneousE. coliattachment allows one to immobilize the cells on challenging material surfaces such as synthetic polymers. Therefore, we envision that mussel-inspired catecholamine yielded stickyE. colithat can be used as a new type of engineered microbe for various emerging fields, such as whole living cell attachment on versatile material surfaces, cell-to-cell communication systems, and many others.

scholarly journals Eliminating false positives in a qPCR assay for the detection of the uidA gene in Escherichia coli

2013 ◽  
Vol 11 (3) ◽  
pp. 382-386 ◽  
Author(s):  
Richard Kibbee ◽  
Natalie Linklater ◽  
Banu Örmeci
Keyword(s):  
Escherichia Coli ◽  
Quantitative Polymerase Chain Reaction ◽  
Qpcr Assay ◽  
Uida Gene ◽  
Chain Reaction ◽  
Taq Polymerase ◽  
E Coli ◽  
Gene Copies ◽  
Polymerase Chain ◽  
Low Levels

Due to contaminant Escherichia coli DNA present in recombinant Taq polymerase reagents, it is not possible to reliably detect low levels of E. coli in samples using the quantitative polymerase chain reaction (qPCR) assay. Native Taq polymerase was successfully used in this study to detect five uidA gene copies (5 fg of genomic DNA) of the uidA gene.

scholarly journals Mineralization and Sticky Trickery of a Barnacle Cement Protein Resolved Computationally

2021 ◽  
Author(s):  
Akshita Kumar ◽  
Harini Mohanram ◽  
Chandra Verma ◽  
Ali Miserez
Keyword(s):  
Cement Protein ◽  
Barnacle Cement

scholarly journals A Clean-In-Place Type Sanitation Method Validation for a Benchtop Meat Grinder

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
C. E. Rayfield ◽  
R. Jadeja ◽  
S. Billups
Keyword(s):  
Lactic Acid ◽  
Foodborne Pathogens ◽  
Peracetic Acid ◽  
Deionized Water ◽  
Cross Contamination ◽  
Direct Plating ◽  
Water Ice ◽  
E Coli ◽  
Different Types ◽  
Low Levels

ObjectivesThis research is designed to validate a novel clean-in-place type antimicrobial ice-based meat grinder sanitation method.Materials and MethodsFour different types of antimicrobial ice were prepared from peracetic acid (PAA, 350 mg/L) and combination PAA with 2% FreshFX® (PAAF), 2% Paradigm® (PAAP) and 2% lactic acid (PAAL). The grinders were inoculated by processing 400 g beef trim containing 400 μL of E. coli O157:H7 or S. Typhimurium DT 104 suspensions at 8.4 to 8.7 (high inoculation) and 5.3 to 5.5 (low inoculation) log CFU/mL. Each meat grinder was then treated by processing 1000 g of antimicrobial ice and 500 mL of corresponding antimicrobial solution. At the end of each treatment, 400 g un-inoculated beef was processed through the meat grinder, and the resulting ground beef was then analyzed for the presence of target pathogens by direct plating and after enrichment. Efficacies of antimicrobial ice-based treatments were compared with 1000 g deionized water ice + 500 mL deionized water (DI), and no treatment (NT) controls.ResultsAll antimicrobial ice treatments were able to reduce cross-contamination to non-detectable levels from the meat grinders inoculated at the low levels of pathogens, but after enrichment, target pathogens were detected in all the samples. Recoveries from the meat grinder inoculated with high levels of pathogens ranged from 5.95 to 3.50 log CFU/g and 5.86 to 3.46 log CFU/g for E. coli O157:H7 and S. Typhimurium DT 104, respectively. All antimicrobial ice treatments were significantly (p ≤ 0.05) more effective in reducing cross-contamination in comparison of NT and DI controls. The microbial reductions achieved by different antimicrobial ice treatments were not significantly (p ≤ 0.05) different from each other.ConclusionThe antimicrobial ice-based meat grinder sanitation technique could effectively reduce foodborne pathogens from meat grinders without needing meat grinder disassembly.

scholarly journals Justification of sorption composite usage on the basis of nanodisperse silica for sepsis prevention in complex treatment of purulent-inflammatory processes

2019 ◽  
Vol 41 part 3 (2) ◽  
pp. 45-50
Author(s):  
O. A. Viltsaniuk ◽  
P. V. Belyaev ◽  
T. P. Osolodchenko ◽  
O. O. Viltsaniuk
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Properties ◽  
Statistical Processing ◽  
Toxic Substances ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
E Coli ◽  
Adhesion Ability ◽  
Treatment And Prevention ◽  
Inflammatory Processes

Introduction. The problem of purulent-inflammatory processes treatment and the prevention of sepsis remains one of the most pressing problems of surgery.Purpose of the study. Is to estimate the effectiveness of sorption composition with antimicrobial properties on the basis of nanodisperse silica on the adhesive properties of microorganisms and to substantiate the expediency of its use for the purulent and inflammatory processes treatment and prevention of sepsis.Materials and methods.To determine the antimicrobial activity and the influence of the antiseptics of decasan, myramistin, ethonium, chlorhexidine and the sorption on the microorganisms adhesion properties composition was used the method of diffusion in agar of the museum strains of microorganisms S. Aureus ATCC 25923, E. Coli ATCC 25922, R. Vulgaris 4636, R. Aureginosa ATCC 27853, S. AIbicans 855/653, SI. Perfringens 28, Peptostreptococcus anaerobicus 22, Bacteroides fragilis 13/83, and clinical strains of S. Aureus, R. Aeuroginosa, E. Coli. Adhesive properties of microorganisms were studied according to the Brillis method et al. (1986) with the subsequent statistical processing of the data.Results. Studies have shown that antiseptics have high antimicrobial activity and reduce the adhesion ability of microorganisms. But the use of only antiseptics or only antibiotics for the purification of purulent foci can lead to toxins absorption and tissue decay products from purulent foci. That processes could be the trigger mechanism for sepsis development. The sorption composition is able to reduce the adhesive activity of bacteria, allows to absorb toxic substances from pathological foci, what preventing their resorption and thereby prevent the development of sepsis.Conclusions. The composition made from sorbents and antiseptics is not inferior to antimicrobial activity to antiseptics, which can reduce the virulence of bacteria, by reducing their adhesive activity, and absorb toxins of microorganisms and tissue decomposition products on their surface, thus prevent their absorption, which will prevent the purulent-inflammatory process progression and sepsis development.Keywords: sorption composition, nanodisperse silica, antiseptics, adhesive properties of microorganisms, prevention of sepsis.

scholarly journals SHV-16, a β-Lactamase with a Pentapeptide Duplication in the Omega Loop

2001 ◽  
Vol 45 (9) ◽  
pp. 2480-2485 ◽  
Author(s):  
Corinne Arpin ◽  
Roger Labia ◽  
Catherine Andre ◽  
Cécile Frigo ◽  
Zoubida El Harrif ◽  
...  
Keyword(s):  
Clinical Isolate ◽  
Donor Cell ◽  
Fold Increase ◽  
Site Directed Mutagenesis ◽  
Resistance Pattern ◽  
E Coli ◽  
Omega Loop ◽  
Low Levels ◽  
Encoding Gene ◽  
Level Resistance

ABSTRACT A clinical isolate of Klebsiella pneumoniae was found to be resistant to ampicillin (MIC of 128 μg/ml), ticarcillin (MIC of 512 μg/ml), and ceftazidime (MIC of 128 μg/ml) and susceptible to all other β-lactams; a synergistic effect between clavulanate and ceftazidime suggested the presence of an extended-spectrum β-lactamase (ESBL). Transconjugants inEscherichia coli were obtained at low levels (10−7 per donor cell) and exhibited a similar β-lactam resistance pattern (resistant to ampicillin, ticarcillin, and ceftazidime at 64 μg/ml). The ESBL, pI 7.6, was encoded by a large plasmid (>100 kb) which did not carry any other resistance determinant. The ESBL-encoding gene was amplified by PCR usingbla SHV-specific primers and was sequenced. The deduced amino acid sequence of the SHV-16 ESBL showed that it differed from SHV-1 by only a pentapeptide insertion (163DRWET167) corresponding to a tandem duplication in the omega loop. The implication of the 163a-DRWET163b-DRWET sequence in ceftazidime resistance was confirmed by cloning either bla SHV-1 orbla SHV-16 in the same vector, subsequently introduced in the same E. coli strain. Under these isogenic conditions, SHV-16 conferred a 32-fold increase in ceftazidime MIC compared to that with SHV-1. Furthermore, site-directed mutagenesis experiments modifying either E166aA or E166bA revealed that the functional glutamic residue was that located in the first copy of the duplicated sequence. But surprisingly, the second E166b also conferred a low-level resistance to ceftazidime. This work is the first description of a class A enzyme exhibiting an extended substrate specificity due to an insertion instead of a nucleotide substitution(s) in a clinical isolate.

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