scholarly journals Development of a novel glycoengineering platform for the rapid production of conjugate vaccines.

2021 ◽  
Author(s):  
Sherif Abouelhadid ◽  
Elizabeth Atkins ◽  
Emily Kay ◽  
Ian Passmore ◽  
Simon J North ◽  
...  
Keyword(s):  
Design Method ◽  
Bacterial Species ◽  
Mobile Element ◽  
Fold Increase ◽  
Conjugate Vaccines ◽  
Bacterial Diseases ◽  
E Coli ◽  
Escherichia Coli Cells ◽  
Novel Method ◽  
A Current

Antimicrobial resistance (AMR) is threatening the lives of millions worldwide. Antibiotics which once saved countless lives, are now failing, ushering in vaccines development as a current global imperative. Conjugate vaccines produced either by chemical synthesis or biologically in Escherichia coli cells, have been demonstrated to be safe and efficacious in protection against several deadly bacterial diseases. However, conjugate vaccines assembly and production have several shortcomings which hinders their wider availability. Here, we developed a tool, Mobile-element Assisted Glycoconjugation by Insertion on Chromosome, MAGIC, a novel method that overcomes the limitations of the current conjugate vaccine design method(s). We demonstrate at least 2-fold increase in glycoconjugate yield via MAGIC when compared to conventional bioconjugate method(s). Furthermore, the modularity of the MAGIC platform also allowed us to perform glycoengineering in genetically intractable bacterial species other than E. coli. The MAGIC system promises a rapid, robust and versatile method to develop vaccines against bacteria, especially AMR pathogens, and could be applied for biopreparedness.

scholarly journals Analysis of Genomes of Bacterial Isolates from Lameness Outbreaks in Broilers

2020 ◽  
Author(s):  
N. Simon Ekesi ◽  
Beata Dolka ◽  
Adnan A.K. Alrubaye ◽  
Douglas D. Rhoads
Keyword(s):  
Escherichia Coli ◽  
Broiler Chickens ◽  
Bacterial Species ◽  
Mobile Element ◽  
Mobile Dna ◽  
E Coli ◽  
Host Shifts ◽  
Sister Clade ◽  
Commercial Broiler ◽  
Genome Assemblies

AbstractWe investigated lameness outbreaks at commercial broiler farms in Arkansas. From Bacterial Chondronecrosis with Osteomyelitis (BCO) lesions, we obtained different isolates of distinct bacterial species. Genome assemblies forEscherichia coliandStaphylococcus aureusisolates show that BCO-lameness pathogens on farms can differ significantly. Genomes assembled fromEscherichia coliisolates from three different farms were quite different from each other, and more similar to isolates from different hosts and geographical locations. The S aureus genomes were closely related to chicken isolates from Europe, and appear to have been restricted to chicken hosts for more than 40 years. Detailed analyses of genomes from this clade of chicken isolates with a sister clade of human isolates, suggests the acquisition of a particular pathogenicity island in the transition from human to chicken pathogen and that pathogenesis in chickens may depend on this mobile element. Phylogenomics is consistent with more frequent host shifts forE. coli, whileS. aureusappears to be highly host restricted. Isolate-specific genome characterizations will help further our understanding of the disease mechanisms and spread of BCO-lameness, a significant animal welfare issue.ImportanceDetailed inspection of the genome sequences of different bacterial species associated with causing lameness in broiler chickens reveals that one species,E. coli, appears to easily switch hosts from humans to chickens and other host species. Conversely, isolates ofS. aureusappear to be restricted to specific hosts. One potential mobile DNA element has been identified that may be critical for causing disease in chickens forS. aureus.

scholarly journals Identification and Characterization of a Putative Manganese Export Protein in Vibrio cholerae

2016 ◽  
Vol 198 (20) ◽  
pp. 2810-2817 ◽  
Author(s):  
Carolyn R. Fisher ◽  
Elizabeth E. Wyckoff ◽  
Eric D. Peng ◽  
Shelley M. Payne
Keyword(s):  
Vibrio Cholerae ◽  
Bacterial Species ◽  
Fold Increase ◽  
Bacterial Cells ◽  
Intracellular Iron ◽  
Content Type ◽  
E Coli ◽  
Import And Export ◽  
Export Protein

ABSTRACTManganese plays an important role in the cellular physiology and metabolism of bacterial species, including the human pathogenVibrio cholerae. The intracellular level of manganese ions is controlled through coordinated regulation of the import and export of this element. We have identified a putative manganese exporter (VC0022), namedmneA(manganeseexporterA), which is highly conserved amongVibriospp. AnmneAmutant exhibited sensitivity to manganese but not to other cations. Under high-manganese conditions, themneAmutant showed an almost 50-fold increase in intracellular manganese levels and reduced intracellular iron relative to those of its wild-type parent, suggesting that the mutant's manganese sensitivity is due to the accumulation of toxic levels of manganese and reduced iron. Expression ofmneAsuppressed the manganese-sensitive phenotype of anEscherichia colistrain carrying a mutation in the nonhomologous manganese export gene,mntP, further supporting a manganese export function forV. choleraeMneA. The level ofmneAmRNA was induced approximately 2.5-fold after addition of manganese to the medium, indicating regulation of this gene by manganese. This study offers the first insights into understanding manganese homeostasis in this important pathogen.IMPORTANCEBacterial cells control intracellular metal concentrations by coordinating acquisition in metal-limited environments with export in metal-excess environments. We identified a putative manganese export protein, MneA, inVibrio cholerae. AnmneAmutant was sensitive to manganese, and this effect was specific to manganese. ThemneAmutant accumulated high levels of intracellular manganese with a concomitant decrease in intracellular iron levels when grown in manganese-supplemented medium. Expression ofmneAintranssuppressed the manganese sensitivity of anE. coli mntPmutant. This study is the first to investigate manganese export inV. cholerae.

Realizing Dynamic Thermal Laser Stimulation by Lock-in IR-OBIRCH Assisted with a Current Detection Probe Head

2013 ◽  
Author(s):  
Chunlei Wu ◽  
Suying Yao
Keyword(s):  
Operating Condition ◽  
Laser Stimulation ◽  
Detection Probe ◽  
Novel Method ◽  
Lock In ◽  
Current Detection ◽  
Parametric Failure ◽  
A Current ◽  
Probe Head

Abstract Lock-in IR-OBIRCH analysis, as a kind of static thermal laser stimulation (S-TLS) technique, is very effective to isolate a fault for the parametric failure cases. However, its capability is limited to localize a defect when the IC is operated under a defined operating condition. Whereas the dynamic thermal laser stimulation (D-TLS) technique is good at locating a fault while the IC is operated under some functions to activate the failure. In this paper, a novel method is presented to realize DTLS just by Lock-in IR-OBIRCH assisted with a Current Detection Probe Head. Two cases are studied to demonstrate the effectiveness of this method.

Efficacy of Silver Nanoparticles Synthesized from Hymenocallis species (Spider Lilly) Leaf Extract as Antimicrobial Agents

2019 ◽  
Vol 12 (5) ◽  
pp. 4644-4647
Author(s):  
K.K. Gupta ◽  
Neha Kumari ◽  
Neha Sinha ◽  
Akruti Gupta
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Antimicrobial Agents ◽  
Color Change ◽  
Bacterial Species ◽  
Antimicrobial Property ◽  
Biogenic Synthesis ◽  
E Coli ◽  
Light Yellow ◽  
Antibiotic Property

Biogenic synthesis of silver nanoparticles synthesized from Hymenocallis species (Spider Lilly) leaf extract was subjected for investigation of its antimicrobial property against four bacterial species (E. coli, Salmonella sp., Streptococcus sp. & Staphylococcus sp.). The results revealed that synthesized nanoparticles solution very much justify the color change property from initial light yellow to final reddish brown during the synthesis producing a characteristics absorption peak in the range of 434-466 nm. As antimicrobial agents, their efficacy was evaluated by analysis of variance in between the species and among the different concentration of AgNPs solution, which clearly showed that there was significant variation in the antibiotic property between the four different concentrations of AgNPs solution and also among four different species of bacteria taken under studies. However, silver nanoparticles solution of 1: 9 and 1:4 were proved comparatively more efficient as antimicrobial agents against four species of bacteria.

Substituted 6,7-dimethoxy-5-oxo-2,3,5,9b-tetrahydrothiazolo[2,3-a]isoindole- 3-1,1-dioxide Derivatives with Antimicrobial Activity and Docking Assisted Prediction of the Mechanism of their Antibacterial and Antifungal Properties

2020 ◽  
Vol 20 (29) ◽  
pp. 2681-2691
Author(s):  
Athina Geronikaki ◽  
Victor Kartsev ◽  
Phaedra Eleftheriou ◽  
Anthi Petrou ◽  
Jasmina Glamočlija ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Drug Targets ◽  
Bacterial Species ◽  
Pharmaceutical Research ◽  
Docking Studies ◽  
Fungal Species ◽  
Docking Analysis ◽  
E Coli ◽  
Antibacterial And Antifungal

Background: Although a great number of the targets of antimicrobial therapy have been achieved, it remains among the first fields of pharmaceutical research, mainly because of the development of resistant strains. Docking analysis may be an important tool in the research for the development of more effective agents against specific drug targets or multi-target agents 1-3. Methods: In the present study, based on docking analysis, ten tetrahydrothiazolo[2,3-a]isoindole derivatives were chosen for the evaluation of the antimicrobial activity. Results: All compounds showed antibacterial activity against eight Gram-positive and Gram-negative bacterial species being, in some cases, more potent than ampicillin and streptomycin against all species. The most sensitive bacteria appeared to be S. aureus and En. Cloacae, while M. flavus, E. coli and P. aeruginosa were the most resistant ones. The compounds were also tested for their antifungal activity against eight fungal species. All compounds exhibited good antifungal activity better than reference drugs bifonazole (1.4 – 41 folds) and ketoconazole (1.1 – 406 folds) against all fungal species. In order to elucidate the mechanism of action, docking studies on different antimicrobial targets were performed. Conclusion: According to docking analysis, the antifungal activity can be explained by the inhibition of the CYP51 enzyme for most compounds with a better correlation of the results obtained for the P.v.c. strain (linear regression between estimated binding Energy and log(1/MIC) with R 2 =0.867 and p=0.000091 or R 2 = 0.924, p= 0.000036, when compound 3 is excluded.

CDBA based current instrumentation amplifier

2016 ◽  
Vol 4 ◽  
pp. 11 ◽  
Author(s):  
Priyanka Gupta ◽  
Kunal Gupta ◽  
Neeta Pandey ◽  
Rajeshwari Pandey
Keyword(s):  
Current Mode ◽  
Instrumentation Amplifier ◽  
Pspice Simulations ◽  
Differential Gain ◽  
Novel Method ◽  
Current Difference ◽  
A Current

This paper presents a novel method to realize a current mode instrumentation amplifier (CMIA) through CDBA (Current difference Buffered Amplifier). It employs two CDBAs and two resistors to obtain desired functionality. Further, it does not require any resistor matching. The gain can be set according to the resistor values. It offers high differential gain and a bandwidth, which is independent of gain. The working of the circuit is verified through PSPICE simulations using CFOA IC based CDBA realization.

scholarly journals Evolution of Chi motifs in Proteobacteria

2021 ◽  
Author(s):  
Angélique Buton ◽  
Louis-Marie Bobay
Keyword(s):  
Sequence Similarity ◽  
Bacterial Species ◽  
Double Strand Breaks ◽  
Dna Double Strand Breaks ◽  
Large Dataset ◽  
High Sequence Similarity ◽  
Strand Breaks ◽  
E Coli ◽  
Dna Motif ◽  
And Staphylococcus Aureus

Abstract Homologous recombination is a key pathway found in nearly all bacterial taxa. The recombination complex allows bacteria to repair DNA double strand breaks but also promotes adaption through the exchange of DNA between cells. In Proteobacteria, this process is mediated by the RecBCD complex, which relies on the recognition of a DNA motif named Chi to initiate recombination. The Chi motif has been characterized in Escherichia coli and analogous sequences have been found in several other species from diverse families, suggesting that this mode of action is widespread across bacteria. However, the sequences of Chi-like motifs are known for only five bacterial species: E. coli, Haemophilus influenzae, Bacillus subtilis, Lactococcus lactis and Staphylococcus aureus. In this study we detected putative Chi motifs in a large dataset of Proteobacteria and we identified four additional motifs sharing high sequence similarity and similar properties to the Chi motif of E. coli in 85 species of Proteobacteria. Most Chi motifs were detected in Enterobacteriaceae and this motif appears well conserved in this family. However, we did not detect Chi motifs for the majority of Proteobacteria, suggesting that different motifs are used in these species. Altogether these results substantially expand our knowledge on the evolution of Chi motifs and on the recombination process in bacteria.

scholarly journals Inkjet Printing of Polypyrrole Electroconductive Layers Based on Direct Inks Freezing and Their Use in Textile Solid-State Supercapacitors

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3577
Author(s):  
Zbigniew Stempien ◽  
Mohmmad Khalid ◽  
Marcin Kozanecki ◽  
Paulina Filipczak ◽  
Angelika Wrzesińska ◽  
...  
Keyword(s):  
Solid State ◽  
Inkjet Printing ◽  
Surface Resistance ◽  
Spectroscopic Studies ◽  
Polymerization Temperature ◽  
Textile Fabrics ◽  
Symmetric Supercapacitor ◽  
Novel Method ◽  
A Current ◽  
Standard Support

In this work, we propose a novel method for the preparation of polypyrrole (PPy) layers on textile fabrics using a reactive inkjet printing technique with direct freezing of inks under varying temperature up to −16 °C. It was found that the surface resistance of PPy layers on polypropylene (PP) fabric, used as a standard support, linearly decreased from 6335 Ω/sq. to 792 Ω/sq. with the decrease of polymerization temperature from 23 °C to 0 °C. The lowest surface resistance (584 Ω/sq.) of PPy layer was obtained at −12 °C. The spectroscopic studies showed that the degree of the PPy oxidation as well as its conformation is practically independent of the polymerization temperature. Thus, observed tendences in electrical conductivity were assigned to change in PPy layer morphology, as it is significantly influenced by the reaction temperature: the lower the polymerization temperature the smoother the surface of PPy layer. The as-coated PPy layers on PP textile substrates were further assembled as the electrodes in symmetric all-solid-state supercapacitor devices to access their electrochemical performance. The electrochemical results demonstrate that the symmetric supercapacitor device made with the PPy prepared at −12 °C, showed the highest specific capacitance of 72.3 F/g at a current density of 0.6 A/g, and delivers an energy density of 6.12 Wh/kg with a corresponding power density of 139 W/kg.

scholarly journals Characterization of Escherichia coli Strains Derived from Cow Milk of Subclinical and Clinical Cases of Mastitis

2021 ◽  
Vol 11 (2) ◽  
pp. 541
Author(s):  
Katarzyna Grudlewska-Buda ◽  
Krzysztof Skowron ◽  
Ewa Wałecka-Zacharska ◽  
Natalia Wiktorczyk-Kapischke ◽  
Jarosław Bystroń ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Economic Problem ◽  
Cow Milk ◽  
P Value ◽  
Dairy Herds ◽  
E Coli ◽  
Bonferroni Test

Mastitis is a major economic problem in dairy herds, as it might decrease fertility, and negatively affect milk quality and milk yield. Out of over 150 bacterial species responsible for the udder inflammation, Escherichia coli is one of the most notable. This study aimed to assess antimicrobial susceptibility, resistance to dipping agents and biofilm formation of 150 E. coli strains isolated from milk of cows with subclinical and clinical mastitis. The strains came from three dairy herds located in Northern and Central Poland. The statistical analyses were performed with post-hoc Bonferroni test and chi-square test (including Yates correction). The data with a p value of <0.05 were considered significant. We found that the tested strains were mostly sensitive to antimicrobials and dipping agents. It was shown that 37.33% and 4.67% of strains were resistant and moderately resistant to at least one antimicrobial agent, respectively. No extended-spectrum beta-lactamases (ESBL)-producing E. coli were detected. The majority of strains did not possess the ability to form biofilm or formed a weak biofilm. The strong biofilm formers were found only among strains derived from cows with subclinical mastitis. The lowest bacteria number was noted for subclinical mastitis cows’ strains, after stabilization with iodine (3.77 log CFU × cm−2) and chlorhexidine (3.96 log CFU × cm−2) treatment. In the present study, no statistically significant differences in susceptibility to antibiotics and the ability to form biofilm were found among the strains isolated from cows with subclinical and clinical mastitis. Despite this, infections in dairy herds should be monitored. Limiting the spread of bacteria and characterizing the most common etiological factors would allow proper treatment.

scholarly journals Enhancing Terpene Yield from Sugars via Novel Routes to 1-Deoxy-d-Xylulose 5-Phosphate

2014 ◽  
Vol 81 (1) ◽  
pp. 130-138 ◽  
Author(s):  
James Kirby ◽  
Minobu Nishimoto ◽  
Ruthie W. N. Chow ◽  
Edward E. K. Baidoo ◽  
George Wang ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Xylose Reductase ◽  
Pentose Phosphate ◽  
Terpene Biosynthesis ◽  
Content Type ◽  
E Coli ◽  
Pathway Expression ◽  
Terpene Synthesis ◽  
Selection For

ABSTRACTTerpene synthesis in the majority of bacterial species, together with plant plastids, takes place via the 1-deoxy-d-xylulose 5-phosphate (DXP) pathway. The first step of this pathway involves the condensation of pyruvate and glyceraldehyde 3-phosphate by DXP synthase (Dxs), with one-sixth of the carbon lost as CO2. A hypothetical novel route from a pentose phosphate to DXP (nDXP) could enable a more direct pathway from C5sugars to terpenes and also circumvent regulatory mechanisms that control Dxs, but there is no enzyme known that can convert a sugar into its 1-deoxy equivalent. Employing a selection for complementation of adxsdeletion inEscherichia coligrown on xylose as the sole carbon source, we uncovered two candidate nDXP genes. Complementation was achieved either via overexpression of the wild-typeE. coliyajOgene, annotated as a putative xylose reductase, or via various mutations in the nativeribBgene.In vitroanalysis performed with purified YajO and mutant RibB proteins revealed that DXP was synthesized in both cases from ribulose 5-phosphate (Ru5P). We demonstrate the utility of these genes for microbial terpene biosynthesis by engineering the DXP pathway inE. colifor production of the sesquiterpene bisabolene, a candidate biodiesel. To further improve flux into the pathway from Ru5P, nDXP enzymes were expressed as fusions to DXP reductase (Dxr), the second enzyme in the DXP pathway. Expression of a Dxr-RibB(G108S) fusion improved bisabolene titers more than 4-fold and alleviated accumulation of intracellular DXP.

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