Engineering proteinosomes with renewable predatory behaviour towards living organisms

2020 ◽  
Vol 7 (1) ◽  
pp. 157-163 ◽  
Author(s):  
Chunyu Zhao ◽  
Mei Zhu ◽  
Ye Fang ◽  
Xiaoman Liu ◽  
Lei Wang ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Mutual Interaction ◽  
Predatory Behaviour ◽  
E Coli ◽  
Living Organisms

A bio-inspired proteinosome-based material showed programmed mutual interaction with E. coli by controlling the temperature and ionic strength.

scholarly journals CAPSULE PRODUCTION PATTERN OF UROPATHOGENIC ESCHERICHIA COLI OF URINARY TRACT INFECTION PATIENTS IN KIRKUK HOSPITALS

2020 ◽  
Vol 17 (35) ◽  
pp. 621-627
Author(s):  
May Ali Hussien UMRAN ◽  
Sumaya Najim AL-KHATEEB
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Clinical Manifestations ◽  
Uropathogenic Escherichia Coli ◽  
E Coli ◽  
Intestinal Pathogens ◽  
Production Pattern ◽  
Living Organisms

The bacterium Escherichia coli is one of the best free-living organisms studied in depth. It is a surprisingly diverse species, since some strains of E. coli live in the intestine of animals as harmless commensals, while other distinct genotypes, such as an enteropathogenic or enterohemorrhagic E. coli, for example, cause morbidity and death marked as human intestinal pathogens. The purpose of this study was to develop and validate a PCR assay for a known and suspected uropathogenic E. coli virulence factor (kpsMT) gene region to determine the distribution of the gene and its role in the development of clinical diseases of the urinary system. A total of 25 urine samples were collected from patients with urinary tract infection (UTI) at Azadi and Kirkuk hospitals in the city of Kirkuk, Iraq. Samples of both genders and different ages were collected from patients with suspected urinary tract infection according to the clinical manifestations and symptoms diagnosed by the examining physician. The samples were cultured and positive samples were subjected to the IMViC test to identify E. coli bacteria and subsequently identified using the Vitek 2 compact system. Among 25 samples, 24 (96%) showed positive results for bacterial cultural growth. Of these, 17 (68%) were identified as Escherichia coli. Of the total of 17 isolates, 14 from patients with mild urinary tract infection, and 3 from patients with Urosepsis. The kpsMT gene was present in 14 isolates (82.3%), including 11 (78.5%) isolates from patients with mild urinary tract infection, and 3 (100%) isolates from patients with Urosepsis. It was concluded that Escherichia coli is the most prevalent in urine tract infection samples. Due to the abundance of the kpsMT gene in uropathogenic Escherichia coli (UPEC), this gene plays an important role in developing UTI if it is not treated correctly and quickly; mild cases of UTI can turn into Urosepsis.

scholarly journals Minor Alterations in Core Promoter Element Positioning Reveal Functional Plasticity of a Bacterial Transcription Factor

mBio ◽  
2021 ◽  
Author(s):  
Wamiah P. Chowdhury ◽  
Kenneth A. Satyshur ◽  
James L. Keck ◽  
Patricia J. Kiley
Keyword(s):  
Transcription Factor ◽  
Core Promoter ◽  
Promoter Element ◽  
Functional Plasticity ◽  
Iron Sulfur Cluster ◽  
Content Type ◽  
E Coli ◽  
Bacterial Transcription ◽  
Iron Sulfur ◽  
Living Organisms

Transcription regulation is a key process in all living organisms, involving a myriad of transcription factors. In E. coli , the regulator of the iron-sulfur cluster biogenesis pathway, IscR, acts as a global transcription factor, activating the transcription of some pathways and repressing others.

scholarly journals The yliA, -B, -C, and -D Genes of Escherichia coli K-12 Encode a Novel Glutathione Importer with an ATP-Binding Cassette

2005 ◽  
Vol 187 (17) ◽  
pp. 5861-5867 ◽  
Author(s):  
Hideyuki Suzuki ◽  
Takashi Koyanagi ◽  
Shunsuke Izuka ◽  
Akiko Onishi ◽  
Hidehiko Kumagai
Keyword(s):  
Escherichia Coli ◽  
Atp Binding ◽  
Sulfur Source ◽  
Dependent Manner ◽  
Oxygen Species ◽  
E Coli ◽  
Living Organisms ◽  
K 12 ◽  
Atp Binding Cassette

ABSTRACT Glutathione protects cells and organisms from oxygen species and peroxides and is indispensable for aerobically living organisms. Moreover, it acts against xenobiotics and drugs by the formation and excretion of glutathione S conjugates. In this study, we show that the yliA, -B, -C, and -D genes of Escherichia coli K-12 encode a glutathione transporter with the ATP-binding cassette. The transporter imports extracellular glutathione into the cytoplasm in an ATP-dependent manner. This transporter, along with γ-glutamyltranspeptidase, has an important role in E. coli growth with glutathione as a sole sulfur source.

scholarly journals A Stress-Induced Bias in the Reading of the Genetic Code in Escherichia coli

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Adi Oron-Gottesman ◽  
Martina Sauert ◽  
Isabella Moll ◽  
Hanna Engelberg-Kulka
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Ribosomal Protein ◽  
Genetic Code ◽  
Open Reading Frames ◽  
Translation Machinery ◽  
E Coli ◽  
Universal Characteristic ◽  
Living Organisms ◽  
Reading Frames

ABSTRACT Escherichia coli mazEF is an extensively studied stress-induced toxin-antitoxin (TA) system. The toxin MazF is an endoribonuclease that cleaves RNAs at ACA sites. Thereby, under stress, the induced MazF generates a stress-induced translation machinery (STM), composed of MazF-processed mRNAs and selective ribosomes that specifically translate the processed mRNAs. Here, we further characterized the STM system, finding that MazF cleaves only ACA sites located in the open reading frames of processed mRNAs, while out-of-frame ACAs are resistant. This in-frame ACA cleavage of MazF seems to depend on MazF binding to an extracellular-death-factor (EDF)-like element in ribosomal protein bS1 (bacterial S1), apparently causing MazF to be part of STM ribosomes. Furthermore, due to the in-frame MazF cleavage of ACAs under stress, a bias occurs in the reading of the genetic code causing the amino acid threonine to be encoded only by its synonym codon ACC, ACU, or ACG, instead of by ACA. IMPORTANCE The genetic code is a universal characteristic of all living organisms. It defines the set of rules by which nucleotide triplets specify which amino acid will be incorporated into a protein. Our results represent the first existing report on a stress-induced bias in the reading of the genetic code. We found that in E. coli , under stress, the amino acid threonine is encoded only by its synonym codon ACC, ACU, or ACG, instead of by ACA. This is because under stress, MazF generates a stress-induced translation machinery (STM) in which MazF cleaves in-frame ACA sites of the processed mRNAs.

Disinfection performance of nanosilver and impacts of environmental conditions on viral inactivation by nanosilver

2013 ◽  
Vol 14 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Yang Xu ◽  
Xiaona Chu ◽  
Jiangyong Hu ◽  
Say Leong Ong
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Humic Acid ◽  
Ionic Strength ◽  
Environmental Conditions ◽  
Contact Time ◽  
Chloride Ion ◽  
Viral Inactivation ◽  
E Coli ◽  
High Concentrations

Three types of nanosilver materials, which were commercial, chemically-synthesized and biologically-synthesized, respectively, were compared in terms of the disinfection efficiencies against Escherichia coli and MS2 coliphage in order to pinpoint promising material with the best performance. Disinfection results showed biologically-synthesized silver nanoparticles (referred to hereafter as ‘bio-AgNPs’) had the best disinfection performance, 10 mg/L of which was able to inactivate all the E. coli in 1 min (>6 log removals) and achieved 4 log removals of MS2 coliphage. Bio-AgNPs were therefore selected for further study in terms of effects of the concentration and contact time as well as the impacts of environmental conditions on the viral inactivation. Given the viral inactivation profile of bio-AgNPs shown in this study, it could be concluded that viral inactivation by bio-AgNPs could be inhibited by total organic carbon (TOC) (10 mg/L as humic acid) and chloride ion (5 mg/L) to a large extent while Ca2+/Mg2+/ionic strength only had minor effects on the viral inactivation at high concentrations (188 mg/L as CaCO3 of hardness or 5.6 mM of ionic strength, respectively). This part of the study may help enlighten further mechanism studies on viral inactivation by nanosilver.

scholarly journals Zeta potential of bacterial cells: Effect of wash buffers

2017 ◽  
Author(s):  
Wenfa Ng ◽  
Yen-Peng Ting
Keyword(s):  
Ionic Strength ◽  
Zeta Potential ◽  
Cell Surface ◽  
Bacterial Cell ◽  
Phosphate Buffer ◽  
Defined Medium ◽  
Deionized Water ◽  
Nonspecific Adsorption ◽  
E Coli ◽  
Ph Range

Zeta potential, defined as the electric charge at the shear plane, is widely used as a proxy parameter for bacterial cell surface charge. Nonspecific adsorption of ions or polyelectrolytes onto the cell surface, however, alters the value and polarity of the measured zeta potential, leading to erroneous results. Multiple wash and centrifugation steps are commonly used in preparing cells for zeta potential analysis, where various wash buffers (such as 9 g/L NaCl, 0.001M KCl, and 0.1M NaNO3) are routinely used for removing (by charge screening) ions and charged molecules that bind nonspecifically to the cell surface. Using Escherichia coli DH5α grown in LB Lennox (with 2 g/L glucose), experiment data showed that the zeta potential-pH profile was not significantly different over the pH range from 2 to 12 for deionized water, 9 g/L NaCl, and phosphate buffer saline (PBS) wash buffers. As LB Lennox is a low salt medium without a phosphate buffer, it was likely that the extent of nonspecific adsorption of ions on the cell surface was not severe, and the different wash buffers would correspondingly not exert much effect on measured zeta potential. Zeta potential-pH profiles for E. coli grown in a semi-defined medium (with a high capacity phosphate buffer system), on the other hand, was significantly different over the pH range from 1 to 12 for deionized water, 9 g/L NaCl, 0.1M NaNO3, 0.1M sodium acetate, and 0.1M sodium citrate wash buffers with the deviation positively correlated with wash buffer’s ionic strength. Furthermore, the point of zero charge (pHzpc) for E. coli grown in the semi-defined medium varies between 1.5 and 3, in an ionic strength dependent manner, for the various wash buffers tested. Collectively, this preliminary study highlights the importance of wash buffer ionic strength in affecting removal efficiency of non-specifically absorbed ions on bacterial cell surface, where a threshold exists (0.15M) for charge screening to be effective. At the upper bound, 0.6M ionic strength might remove cations intrinsic to the cell envelope, leading to possible cell surface damage and erroneous measurements.

scholarly journals Characterization of Water Quality on University Campus

2021 ◽  
pp. 20-28
Author(s):  
Doris Fovwe Ogeleka ◽  
Mildred Chukwuedum Emegha
Keyword(s):  
Safe Drinking Water ◽  
University Campus ◽  
E Coli ◽  
Ph Values ◽  
Regulatory Limits ◽  
Health Association ◽  
Untreated Water ◽  
Petroleum Resources ◽  
Living Organisms

Introduction: Safe drinking water is vital to all human and living organisms. Aim and Study Location: This study appraised untreated water within the Federal University of Petroleum Resources, Effurun (FUPRE) campus with a view to ascertaining their potability. Methodology: The samples were analyzed using the America Public Health Association (APHA), standard protocol Results: The pH indicated that the water were acidic with pH values from 3.50 ± 0.04 to 5.73 ± 0.08. Total iron exceeded the stipulated WHO limit of 0.3 mg/L in some of the locations with concentration varying from 0.232 ± 0.01 to 0.963 ± 0.04. The heavy metal load was relatively low and within regulatory limits. Conclusion: The study concluded that water should not be consumed without treatment due to the non-conforming parameters. In addition, waters with a non-conformance contributed by feacal coliform (E coli) or any other microbial entities should be avoided since serious health water-related diseases (cholera, typhoid, dysentery and diarrheal) may set if consumed.

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