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Escherichia coli

Kaihang Wang, Julius Fredens, Simon F Brunner, Samuel H Kim, Tiongsun Chia, Jason W Chin
Synthetic recoding of genomes, to remove targeted sense codons, may facilitate the encoded cellular synthesis of unnatural polymers by orthogonal translation systems. However, our limited understanding of allowed synonymous codon substitutions, and the absence of methods that enable the stepwise replacement of the Escherichia coli genome with long synthetic DNA and provide feedback on allowed and disallowed design features in synthetic genomes, have restricted progress towards this goal. Here we endow E. coli with a system for efficient, programmable replacement of genomic DNA with long (>100-kb) synthetic DNA, through the in vivo excision of double-stranded DNA from an episomal replicon by CRISPR/Cas9, coupled to lambda-red-mediated recombination and simultaneous positive and negative selection...
October 24, 2016: Nature
S K Jesudoss, J Judith Vijaya, L John Kennedy, P Iyyappa Rajan, Hamad A Al-Lohedan, R Jothi Ramalingam, K Kaviyarasu, M Bououdina
The present work describes the successful synthesize of spinel magnetic ferrite Mn1-xNixFe2O4 (x=0.0, 0.1, 0.2, 0.3, 0.4 & 0.5) nanoparticles via a simple microwave combustion method which was then evaluated for its photocatalytic activity in the degradation of indigo carmine (IC) synthetic dye, a major water pollutant. Our results reveal that the synthesized of Ni(2+) doped MnFe2O4 nanoparticles possess well-crystalline pure cubic spinel phase, exhibit excellent optical and magnetic properties. Further, the photocatalytic performance of the synthesized nanoparticles at different concentration ratios of Ni(2+) ions was monitored by photocatalytic degradation of indigo carmine synthetic dye under UV (λ=365nm) light irradiation...
October 8, 2016: Journal of Photochemistry and Photobiology. B, Biology
Kalle Kipper, Ebba Gregorsson Lundius, Vladimir Curic, Ivana Nikic, Edward A Lemke, Manfred Wiessler, Johan Elf
Small synthetic fluorophores are in many ways superior to fluorescent proteins as labels for imaging. A major challenge is to use them for a protein-specific labeling in living cells. Here, we report on our use of noncanonical amino acids that are genetically encoded via the pyrrolysyl-tRNA/pyrrolysyl-RNA synthetase pair at artificially introduced TAG codons in a recoded E. coli strain. The strain is lacking endogenous TAG codons and the TAG-specific release factor RF1. The amino acids contain bioorthogonal groups that can be clicked to externally supplied dyes, thus enabling protein-specific labeling in live cells...
October 24, 2016: ACS Synthetic Biology
Nayara Halimy Maran, Bruno do Amaral Crispim, Stephanie Ramirez Iahnn, Renata Pires de Araújo, Alexeia Barufatti Grisolia, Kelly Mari Pires de Oliveira
Use of groundwater from private wells in households has increased considerably, owing to a better cost/benefit ratio than that of water provided by local utilities for a fee. However, this water is usually untreated, which makes it a vehicle for diseases. Thus, monitoring this water is necessary to ensure its integrity and quality. We aimed to evaluate the physical, chemical, and microbiological parameters of untreated groundwater drawn from different types of wells, and the antimicrobial susceptibility profile of the bacteria isolated from this water...
October 21, 2016: International Journal of Environmental Research and Public Health
Ya Gao, Yingbo Wang, Yimin Wang, Wenguo Cui
A major goal of biomimetics is the development of chemical compositions and structures that simulate the extracellular matrix. In this study, gelatin-based electrospun composite fibrous membranes were prepared by electrospinning to generate bone scaffold materials. The gelatin-based multicomponent composite fibers were fabricated using co-electrospinning, and the composite fibers of chitosan (CS), gelatin (Gel), hydroxyapatite (HA), and graphene oxide (GO) were successfully fabricated for multi-function characteristics of biomimetic scaffolds...
October 21, 2016: Marine Drugs
Christen Ravn, Ulrika Furustrand Tafin, Bertrand Bétrisey, Søren Overgaard, Andrej Trampuz
Background and purpose - Antibiotic treatment of patients before specimen collection reduces the ability to detect organisms by culture. We investigated the suppressive effect of antibiotics on the growth of non-adherent, planktonic, and surface-related biofilm bacteria in vitro by using sonication and microcalorimetry methods. Patients and methods - Biofilms of Staphylococcus aureus, S. epidermidis, Escherichia coli, and Propionibacterium acnes were formed on porous glass beads and exposed for 24 h to antibiotic concentrations from 1 to 1,024 times the minimal inhibitory concentration (MIC) of vancomycin, daptomycin, rifampin, flucloxacillin, or ciprofloxacin...
October 24, 2016: Acta Orthopaedica
Nadine Czekalski, Stefanie Imminger, Elisabeth Salhi, Marjan Veljkovic, Karolin Kleffel, David Drissner, Frederik Hammes, Helmut Bürgmann, Urs von Gunten
Ozone, a strong oxidant and disinfectant, seems ideal to cope with future challenges of water treatment, such as micropollutants, multiresistant bacteria (MRB) and even intracellular antibiotic resistance genes (ARG), but information on the latter is scarce. In ozonation experiments we simultaneously determined kinetics and dose-dependent inactivation of Escherichia coli and its plasmid-encoded sulfonamide resistance gene sul1 in different water matrixes. Effects in E. coli were compared to an autochthonous wastewater community...
October 24, 2016: Environmental Science & Technology
Zhao-Qing Du, Li-Na Zhang, Qiang Lu, Yi-Fan Ren, Yi Lv, Xue-Min Liu, Xu-Feng Zhang
The standard therapeutic protocols of pyogenic liver abscess (PLA) have not been well established yet. We investigated the clinical characteristics, disease progression, choices of treatments and outcomes of PLA with different size. 410 cases of patients with PLA were enrolled retrospectively from 2000 to 2014, and were grouped as small abscess (≤5 cm, n = 125), large abscess (5 cm to 10 cm, n = 218) and giant abscess (>10 cm, n = 36). The most common bacteria were Klebsiella pneumonia (22%) and Escherichia coli (11%) by pus culture, and Escherichia coli (36...
October 24, 2016: Scientific Reports
Timothy K Lee, Kevin Meng, Handuo Shi, Kerwyn Casey Huang
The peptidoglycan cell wall is an integral organelle critical for bacterial cell shape and stability. Proper cell wall construction requires the interaction of synthesis enzymes and the cytoskeleton, but it is unclear how the activities of individual proteins are coordinated to preserve the morphology and integrity of the cell wall during growth. To elucidate this coordination, we used single-molecule imaging to follow the behaviours of the two major peptidoglycan synthases in live, elongating Escherichia coli cells and after perturbation...
October 24, 2016: Nature Communications
Amna K E Awadallah, Makarim Elfadil M Osman, Mariam A Ibrahim, Emerson S Bernardes, Marcelo Dias-Baruffi, Emadeldin Hassan E Konozy
Three isolectins denoted hereforth MBaL-30, MBaL-60, and MBaL-80 were isolated from seeds extract of Momordica balsamina by 30%, 60%, and 80% ammonium sulfate saturations, respectively. The native molecular weights of these lectins, as judged by gel filtration, were 108, 56, and 160 kDa, respectively. On SDS-PAGE, under reduced condition, 27 kDa band was obtained for all isolectins. The lectins hemagglutinating activities were variably inhibited by d-galactose (minimum inhibitory concentrations = 12.5mM, 50mM, and 0...
October 24, 2016: Journal of Molecular Recognition: JMR
Elie A Saade, Nuntra Suwantarat, Trina F Zabarsky, Brigid Wilson, Curtis J Donskey
BACKGROUND: Recent reports suggest that infections due to fluoroquinolone-resistant Escherichia coli (E. coli) are an increasingly common complication of transrectal biopsy of the prostate (TBP) in the United States. A better understanding of the magnitude and scope of these infections is needed to guide prevention efforts. Our objective is to determine whether the incidence of infections due to fluoroquinolone-resistant E. coli after TBP has increased nationwide in the Veterans Affairs Health Care System and to identify risk factors for infection...
2016: Pathogens & Immunity
Javier Sanchez-Villamil, Gabriela Tapia-Pastrana, Fernando Navarro-Garcia
Inflammatory response is key for the host defense against diarrheagenic Escherichia coli and contributes to the pathogenesis of the disease but there is not a comparative study among different diarrheagenic pathotypes. We analyzed the inflammatory response induced by five diarrheagenic pathotypes in a HT-29 cell infection model. The model was unified to reproduce the pathogenesis of each pathotype. To compare the inflammatory responses we evaluated: (i) nuclear NF-κB and ERK1/2 translocation by confocal microscopy; (ii) kinetics of activation by each pathway detecting p65 and ERK1/2 phosphorylation by Western blotting; (iii) pathways modulation through bacterial infections with or without co-stimulation with TNF-α or EGF; (iv) cytokine profile induced by each pathotype with and without inhibitors of each pathway...
2016: Frontiers in Cellular and Infection Microbiology
Chia-Chih Chang, Kristopher W Kolewe, Yinyong Li, Irem Kosif, Benny D Freeman, Kenneth R Carter, Jessica D Schiffman, Todd Emrick
Hydration is central to mitigating surface fouling by oil and microorganisms. Immobilization of hydrophilic polymers on surfaces promotes retention of water and a reduction of direct interactions with potential foulants. While conventional surface modification techniques are surface-specific, mussel-inspired adhesives based on dopamine effectively coat many types of surfaces and thus hold potential as a universal solution to surface modification. Here, we describe a facile, one-step surface modification strategy that affords hydrophilic, and underwater superoleophobic, coatings by the simultaneous deposition of polydopamine (PDA) with poly(methacryloyloxyethyl phosphorylcholine) (polyMPC)...
March 23, 2016: Advanced Materials Interfaces
Beatriz Pérez Montoro, Nabil Benomar, Leyre Lavilla Lerma, Sonia Castillo Gutiérrez, Antonio Gálvez, Hikmate Abriouel
A collection of 31 Lactobacillus pentosus strains isolated from naturally fermented Aloreña green table olives were screened in depth in the present study for their probiotic potential. Several strains could be considered promising probiotic candidates since they showed good growth capacity and survival under simulated gastro-intestinal conditions (acidic pH of 1.5, up to 4% of bile salts and 5 mM of nitrate), good ability to auto-aggregate which may facilitate their adhesion to host cells as multiple aggregates and the subsequent displacement of pathogens...
2016: Frontiers in Microbiology
Nathan J Alves, Kendrick B Turner, Kyle A DiVito, Michael A Daniele, Scott A Walper
To facilitate the rapid purification of bacterial outer membrane vesicles (OMVs), we developed two plasmid constructs that utilize a truncated, transmembrane protein to present an exterior histidine repeat sequence. We chose OmpA, a highly abundant porin protein, as the protein scaffold and utilized the lac promoter to allow for inducible control of the epitope-presenting construct. OMVs containing mutant OmpA-His6 were purified directly from Escherichia coli culture media on an immobilized metal affinity chromatography (IMAC) Ni-NTA resin...
October 20, 2016: Research in Microbiology
C Patrick McAtee, Christopher A Seid, Molly Hammond, Elissa Hudspeth, Brian P Keegan, Zhuyun Liu, Junfei Wei, Bin Zhan, Raul Arjona-Sabido, Vladimir Cruz-Chan, Eric Dumonteil, Peter J Hotez, Maria Elena Bottazzi
The nucleoside hydrolase gene from Leishmania donovani was cloned and expressed in Escherichia coli as a full length 36-kDa protein (LdNH36). Following lysis and extraction, the protein was purified by anion exchange and gel filtration chromatography. The purified protein had a molecular mass of approximately 36-kDa and was confirmed to be >99% pure. Using a nucleoside hydrolase assay, the protein was found to exhibit a Km of 741 ± 246 μM. Protein integrity was confirmed by lithium dodecyl sulfate polyacrylamide gel electrophoresis (LDS-PAGE), mass spectrometry (MS), and enzymatic assay...
October 20, 2016: Protein Expression and Purification
Jean-Luc Boevé, Tina E Trenczek, Sergio Angeli
Easy bleeding is a defence strategy that allows the larvae of some Tenthredinidae sawfly species to emit deterrent hemolymph when attacked by a predator. However, a drawback of this defence is that hemolymph is frequently in contact with the exterior, thus potentially subjected to multiple microbial infections at any body's integumental spot. Here we aimed to identify physiological traits that are linked to easy bleeding. First, larvae of several sawfly species were subjected to daily experimental losses of hemolymph equivalent to 10% of their body weight, and changes in body weight and survival were recorded...
October 20, 2016: Journal of Insect Physiology
M A Tazón-Varela, H Alonso-Valle, P Muñoz-Cacho, J Gallo-Terán, X Piris-García, L A Pérez-Mier
INTRODUCTION: Knowing the most common microorganisms in our environment can help us to make proper empirical treatment decisions. The aim is to identify those microorganisms causing community-acquired pneumonia. PATIENTS AND METHODS: An observational, descriptive and prospective study was conducted, including patients over 14 years with a clinical and radiographic diagnosis of community-acquired pneumonia during a 383 consecutive day period. A record was made of sociodemographic variables, personal history, prognostic severity scales, progress, and pathogenic agents...
October 20, 2016: Semergen
Zijian Zhang, Liuyi Meng, Congjian Ni, Lanqiu Yao, Fengyu Zhang, Yuji Jin, Xuelang Mu, Shiyu Zhu, Xiaoyu Lu, Shiyu Liu, Congyu Yu, Chenggong Wang, Pu Zheng, Jie Wu, Li Kang, Haoqian M Zhang, Qi Ouyang
We engineered Escherichia coli cells to bind to cyanobacteria by heterologously producing and displaying lectins of the target cyanobacteria on their surface. To prove the efficacy of our approach, we tested this design on Microcystis aeruginosa with microvirin (Mvn), the lectin endogenously produced by this cyanobacterium. The coding sequence of Mvn was C-terminally fused to the ice nucleation protein NC (INPNC) gene and expressed in E. coli. Results showed that E. coli cells expressing the INPNC::Mvn fusion protein were able to bind to M...
October 20, 2016: Journal of Bioscience and Bioengineering
Kang Liao, Yili Chen, Menghe Wang, Penghao Guo, Qiwen Yang, Yuxing Ni, Yunsong Yu, Bijie Hu, Ziyong Sun, Wenxiang Huang, Yong Wang, Anhua Wu, Xianju Feng, Yanping Luo, Zhidong Hu, Yunzhuo Chu, Shulan Chen, Bin Cao, Jianrong Su, Bingdong Gui, Qiong Duan, Shufang Zhang, Haifeng Shao, Haishen Kong, Yingchun Xu
BACKGROUND: Recently, the emergence of multidrug-resistant organisms such as extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae has raised considerable concern regarding the appropriate treatment of intra-abdominal infections (IAIs). In this study, we investigated the molecular characteristics of ESBL among clinical isolates of Escherichia coli and Klebsiella pneumoniae causing IAIs and their pattern of antimicrobial resistance, which can provide useful information about the epidemiology and risk factors associated with these infections...
October 7, 2016: Diagnostic Microbiology and Infectious Disease
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