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https://www.readbyqxmd.com/read/29453395/the-genes-of-the-sulphoquinovose-catabolism-in-escherichia-coli-are-also-associated-with-a-previously-unknown-pathway-of-lactose-degradation
#1
Anna Kaznadzey, Pavel Shelyakin, Evgeniya Belousova, Aleksandra Eremina, Uliana Shvyreva, Darya Bykova, Vera Emelianenko, Anastasiya Korosteleva, Maria Tutukina, Mikhail S Gelfand
Comparative genomics analysis of conserved gene cassettes demonstrated resemblance between a recently described cassette of genes involved in sulphoquinovose degradation in Escherichia coli K-12 MG1655 and a Bacilli cassette linked with lactose degradation. Six genes from both cassettes had similar functions related to carbohydrate metabolism, namely, hydrolase, aldolase, kinase, isomerase, transporter, and transcription factor. The Escherichia coli sulphoglycolysis cassette was thus predicted to be associated with lactose degradation...
February 16, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29437264/insight-on-specificity-of-uracil-permeases-of-the-nat-ncs2-family-from-analysis-of-the-transporter-encoded-in-the-pyrimidine-utilization-operon-of-escherichia-coli
#2
Maria Botou, Panayiota Lazou, Konstantinos Papakostas, George Lambrinidis, Thomas Evangelidis, Emmanuel Mikros, Stathis Frillingos
The uracil permease UraA of Escherichia coli is a structurally known prototype for the ubiquitous Nucleobase-Ascorbate Transporter (NAT) or Nucleobase-Cation Symporter-2 (NCS2) family and represents a well defined subgroup of bacterial homologs that remain functionally unstudied. Here, we analyze four of these homologs, including RutG of E. coli which shares 35% identity with UraA and is encoded in the catabolic rut (pyrimidine utilization) operon. Using amplified expression in E. coli K-12, we show that RutG is a high-affinity permease for uracil, thymine and, at low efficiency, xanthine, and recognizes also 5-fluorouracil and oxypurinol...
February 13, 2018: Molecular Microbiology
https://www.readbyqxmd.com/read/29385126/analysis-of-bacterial-genomes-from-an-evolution-experiment-with-horizontal-gene-transfer-shows-that-recombination-can-sometimes-overwhelm-selection
#3
Rohan Maddamsetti, Richard E Lenski
Few experimental studies have examined the role that sexual recombination plays in bacterial evolution, including the effects of horizontal gene transfer on genome structure. To address this limitation, we analyzed genomes from an experiment in which Escherichia coli K-12 Hfr (high frequency recombination) donors were periodically introduced into 12 evolving populations of E. coli B and allowed to conjugate repeatedly over the course of 1000 generations. Previous analyses of the evolved strains from this experiment showed that recombination did not accelerate adaptation, despite increasing genetic variation relative to asexual controls...
January 31, 2018: PLoS Genetics
https://www.readbyqxmd.com/read/29358499/peptide-transporter-csta-imports-pyruvate-in-escherichia-coli-k-12
#4
Soonkyu Hwang, Donghui Choe, Minseob Yoo, Sanghyuk Cho, Sun Chang Kim, Suhyung Cho, Byung-Kwan Cho
Pyruvate is an important intermediate of central carbon metabolism and connects a variety of metabolic pathways in Escherichia coli Although intracellular pyruvate concentration is dynamically altered and tightly balanced during cell growth, the pyruvate transport system remains unclear. Here, we identified a pyruvate transporter in E. coli using high-throughput transposon sequencing. The transposon mutant library (a total of 5 ×105 mutants) was serially grown with a toxic pyruvate analog (3FP) to enrich transposon mutants lacking pyruvate transport function...
January 22, 2018: Journal of Bacteriology
https://www.readbyqxmd.com/read/29355812/lack-of-cations-in-flow-cytometry-buffers-affect-fluorescence-signals-by-reducing-membrane-stability-and-viability-of-escherichia-coli-strains
#5
Kathrin Tomasek, Tobias Bergmiller, Călin C Guet
Buffers are essential for diluting bacterial cultures for flow cytometry analysis in order to study bacterial physiology and gene expression parameters based on fluorescence signals. Using a variety of constitutively expressed fluorescent proteins in Escherichia coli K-12 strain MG1655, we found strong artifactual changes in fluorescence levels after dilution into the commonly used flow cytometry buffer phosphate-buffered saline (PBS) and two other buffer solutions, Tris-HCl and M9 salts. These changes appeared very rapidly after dilution, and were linked to increased membrane permeability and loss in cell viability...
January 17, 2018: Journal of Biotechnology
https://www.readbyqxmd.com/read/29294852/the-role-of-the-perceptions-of-school-climate-and-teacher-victimization-by-students
#6
Francis L Huang, Colleen Lloyd Eddy, Emily Camp
Violence directed toward teachers in schools is relatively understudied in comparison with other school-based forms of peer aggression (e.g., school bullying). Based on the nationally representative Schools and Staffing Survey (SASS) 2011-2012, approximately 10% of K-12 public school teachers in the United States, received a threat in the past 12 months and 6% reported being physically attacked. The effects of teacher-directed violence are far reaching and affect not just the victimized teacher, but the larger community itself...
July 1, 2017: Journal of Interpersonal Violence
https://www.readbyqxmd.com/read/29288674/a-straightforward-assay-for-measuring-glycogen-levels-and-rpos
#7
Tadayuki Iwase, Chiaki Okai, Yuko Kamata, Akiko Tajima, Yoshimitsu Mizunoe
Cellular glycogen levels reflect the activity of RpoS, an important stress-inducible bacterial sigma factor known to regulate several stress-resistance related genes, such as katE, encoding hydroperoxidase II (HPII), and the glg genes, encoding glycogen synthesis enzymes, in Escherichia coli. In this study, a straightforward assay for measuring glycogen levels and RpoS activity was developed combining the ease and simplicity of qualitative approaches. The assay reagent was a 2% iodine solution (2% iodine/1M NaOH), and the basic principle of this assay is the iodine-glycogen reaction, which produces a reddish brown color that can be measured using a spectrophotometer...
December 27, 2017: Journal of Microbiological Methods
https://www.readbyqxmd.com/read/29280730/phenotype-inference-in-an-escherichia-coli-strain-panel
#8
Marco Galardini, Alexandra Koumoutsi, Lucia Herrera-Dominguez, Juan Antonio Cordero Varela, Anja Telzerow, Omar Wagih, Morgane Wartel, Olivier Clermont, Erick Denamur, Athanasios Typas, Pedro Beltrao
Understanding how genetic variation contributes to phenotypic differences is a fundamental question in biology. Combining high-throughput gene function assays with mechanistic models of the impact of genetic variants is a promising alternative to genome-wide association studies. Here we have assembled a large panel of 696 Escherichia coli strains, which we have genotyped and measured their phenotypic profile across 214 growth conditions. We integrated variant effect predictors to derive gene-level probabilities of loss of function for every gene across all strains...
December 27, 2017: ELife
https://www.readbyqxmd.com/read/29248818/barriers-facilitators-and-potential-strategies-for-increasing-hpv-vaccination-a-statewide-assessment-to-inform-action
#9
Kathleen B Cartmell, Jennifer Young-Pierce, Shannon McGue, Anthony J Alberg, John S Luque, Maria Zubizarreta, Heather M Brandt
OBJECTIVE: The objective was to investigate how state level strategies in South Carolina could maximize HPV vaccine uptake. DESIGN: An environmental scan identified barriers, facilitators, and strategies for improving HPV vaccination in South Carolina. Interviews were conducted with state leaders from relevant organizations such as public health agencies, medical associations, K-12 schools, universities, insurers, and cancer advocacy organizations. A thematic content analysis design was used...
December 7, 2017: Papillomavirus Research
https://www.readbyqxmd.com/read/29240431/solar-photothermal-disinfection-using-broadband-light-absorbing-gold-nanoparticles-and-carbon-black
#10
Stephanie Loeb, Chuanhao Li, Jae-Hong Kim
A simple heat treatment, perhaps the most globally recognized point-of-use water sterilization method, is seemingly effective against all major pathogens of concern, but bulk water boiling is not energy efficient or sustainable. Herein, we present the first application of solar-to-thermal converting nanomaterials for the direct inactivation of bacteria and viruses in drinking water through the application of Au nanorods, carbon black, and Au nanorod-carbon black composite materials as light absorbers. With broad absorption bands spanning the visible and near-infrared wavelengths, at sufficient concentrations, these nanoparticles induce multiple scattering events, increasing photon absorption probability and concentrating the light within a small spatial domain, leading to localized, intense heating that inactivates microorganisms in close proximity...
December 14, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29237285/inhibition-of-diverse-dsba-enzymes-in-multi-dsba-encoding-pathogens
#11
Makrina Totsika, Dimitrios Vagenas, Jason J Paxman, Geqing Wang, Rabeb Dhouib, Pooja Sharma, Jennifer L Martin, Martin J Scanlon, Begoña Heras
AIMS: DsbA catalyses disulfide bond formation in secreted and outer membrane proteins in bacteria. In pathogens, DsbA is a major facilitator of virulence constituting a target for antivirulence antimicrobial development. However, many pathogens encode multiple and diverse DsbA enzymes for virulence factor folding during infection. The aim of this study was to determine whether our recently identified inhibitors of <i>Escherichia coli </i>K-12 DsbA can inhibit the diverse DsbA enzymes found in two important human pathogens and attenuate their virulence...
December 14, 2017: Antioxidants & Redox Signaling
https://www.readbyqxmd.com/read/29225287/lysogenisation-of-shiga-toxin-encoding-bacteriophage-represses-cell-motility
#12
Shoichi Mitsunaka, Naoki Sudo, Yasuhiko Sekine
Bacteriophages are genetic elements that play key roles in the evolution and diversification of bacterial genomes. The Shiga toxin (Stx)-encoding phage plays an important role in the horizontal transfer of the stx gene. However, the influence of the Stx phage integration on the physiological properties and gene expression pattern of the host have not been clearly resolved. In this study, we constructed the Sp5 lysogen through lysogenisation of E. coli K-12 by Sp5, an Stx2 phage in enterohaemorrhagic E. coli (EHEC) O157:H7 Sakai, and examined the effect of the resulting lysogen on cell motility under various growth conditions...
December 8, 2017: Journal of General and Applied Microbiology
https://www.readbyqxmd.com/read/29214812/prevalence-and-implementation-practices-of-school-salad-bars-across-grade-levels
#13
Meg Bruening, Marc A Adams, Punam Ohri-Vachaspati, Jane Hurley
PURPOSE: To assess the prevalence of school salad bars in Arizona and to describe common practices of salad bar use among school nutrition managers across grade level. DESIGN: Cross-sectional web-based surveys. PARTICIPANTS: School nutrition managers from elementary, middle, high, and K-12 schools (N = 648). MEASURES: Prevalence of salad bars; implementation practices such as years with salad bar, salad bar type, location, monitor, and reimbursement practices; and food-related components of salad bars including frequency of items, popular items, and sources of food...
January 1, 2017: American Journal of Health Promotion: AJHP
https://www.readbyqxmd.com/read/29210309/identification-and-characterization-of-a-locus-putatively-involved-in-colanic-acid-biosynthesis-in-vibrio-alginolyticus-zj-51
#14
Xiaochun Huang, Chang Chen, Chunhua Ren, Yingying Li, Yiqin Deng, Yiying Yang, Xiongqi Ding
Colanic acid (CA) is a group I extracellular polysaccharide (EPS) that contributes to resistance against adverse environments in many members of the Enterobacteriaceae. In the present study, a genetic locus EPSC putatively involved in CA biosynthesis was identified in Vibrio alginolyticus ZJ-51, which undergoes colony morphology variation between translucent/smooth (ZJ-T) and opaque/rugose (ZJ-O). EPSC in ZJ-T carries 21 ORFs and resembles the CA cluster of Escherichia coli K-12. The deletion of EPSC led to decreased EPS and biofilm formation in both genetic backgrounds but no alternation of lipopolysaccharide...
December 6, 2017: Biofouling
https://www.readbyqxmd.com/read/29205229/crispr-cas-mediated-gene-silencing-reveals-racr-to-be-a-negative-regulator-of-ydas-and-ydat-toxins-in-escherichia-coli-k-12
#15
Gargi Bindal, Revathy Krishnamurthi, Aswin Sai Narain Seshasayee, Devashish Rath
Bacterial genomes are rich in horizontally acquired prophages. racR is an essential gene located in the rac prophage that is resident in many Escherichia coli genomes. Employing a clustered regularly interspaced short palindromic repeat (CRISPR)-Cas-based gene silencing approach, we show that RacR is a negative regulator of the divergently transcribed and adjacent ydaS-ydaT operon in Escherichia coli K-12. Overexpression of YdaS and YdaT due to RacR depletion leads to cell division defects and decrease in survival...
November 2017: MSphere
https://www.readbyqxmd.com/read/29205228/repression-of-ydas-toxin-is-mediated-by-transcriptional-repressor-racr-in-the-cryptic-rac-prophage-of-escherichia-coli-k-12
#16
Revathy Krishnamurthi, Swagatha Ghosh, Supriya Khedkar, Aswin Sai Narain Seshasayee
Horizontal gene transfer is a major driving force behind the genomic diversity seen in prokaryotes. The cryptic rac prophage in Escherichia coli K-12 carries the gene for a putative transcription factor RacR, whose deletion is lethal. We have shown that the essentiality of racR in E. coli K-12 is attributed to its role in transcriptionally repressing toxin gene(s) called ydaS and ydaT, which are adjacent to and coded divergently to racR. IMPORTANCE Transcription factors in the bacterium E. coli are rarely essential, and when they are essential, they are largely toxin-antitoxin systems...
November 2017: MSphere
https://www.readbyqxmd.com/read/29199446/advances-in-school-based-interventions-for-students-with-autism-spectrum-disorder-introduction-to-the-special-issue
#17
Cynthia M Anderson, Tristram Smith, Susan M Wilczynski
As the diagnosis of autism spectrum disorder has increased, so too has research on interventions to address core and associated features of autism. Although many methodologically rigorous studies on interventions have been reported, their relevance to educators is somewaht unclear. For example, only about 32% of evidence-based strategies identifed in these reviews were conducted in k-12 settings. Current literature also is limited in that, although many studies show that interventions can improve the communication and social interaction skills of individuals with autism, most of this work has been conducted with pre-school children; questions remain about the generality of these findings to school-aged children...
January 2018: Behavior Modification
https://www.readbyqxmd.com/read/29195013/effect-of-bacterial-growth-rate-on-bacteriophage-population-growth-rate
#18
Dominik Nabergoj, Petra Modic, Aleš Podgornik
It is important to understand how physiological state of the host influence propagation of bacteriophages (phages), due to the potential higher phage production needs in the future. In our study, we tried to elucidate the effect of bacterial growth rate on adsorption constant (δ), latent period (L), burst size (b), and bacteriophage population growth rate (λ). As a model system, a well-studied phage T4 and Escherichia coli K-12 as a host was used. Bacteria were grown in a continuous culture operating at dilution rates in the range between 0...
December 1, 2017: MicrobiologyOpen
https://www.readbyqxmd.com/read/29192157/linking-functional-connectivity-and-dynamic-properties-of-resting-state-networks
#19
Won Hee Lee, Sophia Frangou
Spontaneous brain activity is organized into resting-state networks (RSNs) involved in internally-guided, higher-order mental functions (default mode, central executive and salience networks) and externally-driven, specialized sensory and motor processing (auditory, visual and sensorimotor networks). RSNs are characterized by their functional connectivity in terms of within-network cohesion and between-network integration, and by their dynamic properties in terms of synchrony and metastability. We examined the relationship between functional connectivity and dynamic network features using fMRI data and an anatomically constrained Kuramoto model...
November 30, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29188187/genome-sequence-and-analysis-of-escherichia-coli-production-strain-ls5218
#20
Jacqueline M Rand, Gina C Gordon, Christopher R Mehrer, Brian F Pfleger
Escherichia coli strain LS5218 is a useful host for the production of fatty acid derived products, but the genetics underlying this utility have not been fully investigated. Here, we report the genome sequence of LS5218 and a list of large mutations and single nucleotide permutations (SNPs) relative to E. coli K-12 strain MG1655. We discuss how genetic differences may affect the physiological differences between LS5218 and MG1655. We find that LS5218 is more closely related to E. coli strain NCM3722 and suspect that small genetic differences between K-12 derived strains may have a significant impact on metabolic engineering efforts...
December 2017: Metabolic Engineering Communications
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