scholarly journals Functional channels in mature E. coli colonies

2019 ◽  
Author(s):  
Liam M. Rooney ◽  
William B. Amos ◽  
Paul A. Hoskisson ◽  
Gail McConnell
Keyword(s):  
Public Health ◽  
Spatial Scales ◽  
Antimicrobial Drugs ◽  
Characteristic Structure ◽  
Present Evidence ◽  
E Coli ◽  
Simultaneous Imaging ◽  
Multiple Spatial Scales ◽  
Dispersal Agents ◽  
And Function

AbstractBiofilms are important in medicine, industry and the natural environment, however their structure is largely unexplored across multiple spatial scales. We have studied the architecture of mature Escherichia coli macro-colony biofilms by means of the Mesolens, an optical system which uniquely allows simultaneous imaging of individual bacteria and over one hundred cubic millimetres of its biofilm milieu. Our chief finding is the presence of intra-colony channels on the order of 10 μm in diameter in E. coli biofilms. These channels have a characteristic structure and reform after total mechanical disaggregation of the colony. We present evidence that the channels transport particles and function to assist the absorption of nutrients. These channels potentially offer a new route for the delivery of dispersal agents or antimicrobial drugs to biofilms, ultimately lowering their impact on public health and industry.

scholarly journals Intra-colony channels in E. coli function as a nutrient uptake system

2020 ◽  
Vol 14 (10) ◽  
pp. 2461-2473 ◽  
Author(s):  
Liam M. Rooney ◽  
William B. Amos ◽  
Paul A. Hoskisson ◽  
Gail McConnell
Keyword(s):  
Spatial Scales ◽  
Emergent Property ◽  
Field Of View ◽  
Uptake System ◽  
Antimicrobial Drugs ◽  
Biofilm Growth ◽  
Characteristic Structure ◽  
E Coli ◽  
Simultaneous Imaging ◽  
Multiple Spatial Scales

Abstract The ability of microorganisms to grow as aggregated assemblages has been known for many years, however their structure has remained largely unexplored across multiple spatial scales. The development of the Mesolens, an optical system which uniquely allows simultaneous imaging of individual bacteria over a 36 mm2 field of view, has enabled the study of mature Escherichia coli macro-colony biofilm architecture like never before. The Mesolens enabled the discovery of intra-colony channels on the order of 10 μm in diameter, that are integral to E. coli macro-colony biofilms and form as an emergent property of biofilm growth. These channels have a characteristic structure and re-form after total mechanical disaggregation of the colony. We demonstrate that the channels are able to transport particles and play a role in the acquisition of and distribution of nutrients through the biofilm. These channels potentially offer a new route for the delivery of dispersal agents for antimicrobial drugs to biofilms, ultimately lowering their impact on public health and industry.

scholarly journals Microorganisms Resistant to Antimicrobials in Wild Canarian Egyptian Vultures (Neophron percnopterus majorensis)

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 970
Author(s):  
Alejandro Suárez-Pérez ◽  
Juan Alberto Corbera ◽  
Margarita González-Martín ◽  
José Antonio Donázar ◽  
Rubén Sebastián Rosales ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Human Population ◽  
Resistant Bacteria ◽  
Livestock Waste ◽  
Antimicrobial Drugs ◽  
E Coli ◽  
Bird Of Prey ◽  
Neophron Percnopterus ◽  
Low Levels

Due to their predatory habits, raptors may serve as indicators of the presence of antimicrobial-resistant bacteria in the environment, but they also represent a public health risk for livestock and humans because they can act as reservoirs, sources and spreaders of these bacteria. Our objective was to determine the presence of antimicrobial-resistant bacteria in cloacal samples of Canarian Egyptian vultures (Neophron percnopterus majorensis), an endemic bird of prey. One hundred and forty-two cloacal swabs were obtained; Escherichia coli was isolated from 80.28% and Salmonella from 6.3% of these samples. Low levels of susceptibility to ampicillin, tetracycline and trimethoprim/sulfamethoxazole were found. About 20% of the isolates were resistant or presented intermediate susceptibility to fluoroquinolones. Surprisingly, we found isolates resistant to imipenem (6.96%). Isolates from chicks were more susceptible to antimicrobial drugs than adult and immature birds. About 50% of E. coli isolates were resistant to ampicillin, tetracycline and trimethoprim/sulfamethoxazole, and about 20% to piperacillin, enrofloxacin and marbofloxacin. High percentages of isolates of Salmonella were found to be resistant to cephalexin (88%) and aminoglycosides (greater than 77%). Our results support the idea that raptors could act as reservoirs of Salmonella and antimicrobial-resistant bacteria, posing a risk not only to wildlife but also to livestock and the human population, thus reinforcing the need to minimize the exposure of wildlife to antimicrobial agent through human and livestock waste.

scholarly journals Occurrence of Antimicrobial Resistance in Foodborne Bacteria (Campylobacter and E. coli): A Food Safety Issue and Public Health Hazard

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohamed-Yousif Ibrahim Mohamed
Keyword(s):  
Public Health ◽  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Safety Issue ◽  
Health Hazard ◽  
Animal Husbandry ◽  
Antimicrobial Drugs ◽  
E Coli ◽  
Health Significance ◽  
Human Infections

Campylobacter and Escherichia coli (E. coli) are prominent bacterial causes of human gastroenteritis in the developing countries and the emergence of antibiotic resistance of these bacteria has been widely reported to be on the increase, particularly because of the increase in the number of resistant Campylobacter and E. coli isolated from human infections. The widespread use of antimicrobial drugs for therapeutic, prophylactic, and preventive purposes in modern food animal husbandry is a great concern in terms of the development of antibiotic resistance in many bacteria, and, therefore, a potential public health threat. This review simply describes the occurrence, spreading and public health significance of antimicrobial resistance in Campylobacter and E. coli.

scholarly journals Spatial Structure among the Geometric Earthworks of western Amazonia (Acre, Brazil)

2019 ◽  
Author(s):  
Philip Riris
Keyword(s):  
Analytical Approach ◽  
Amazon Basin ◽  
Spatial Scales ◽  
Relative Importance ◽  
Factors Affecting ◽  
Multiple Spatial Scales ◽  
Archaeological Models ◽  
And Function ◽  
Open Question ◽  
Territorial Integration

Fieldwork and desk-based research in the western Amazon basin has led to an explosive growth in the state of knowledge surrounding the pre-Columbian archaeology of this region. Previously thought to be a sparsely occupied environment, archaeologists have recorded hundreds of geometric earthworks between the Purús and Acre rivers in recent years, spurring renewed interest in understanding the distribution, age, and function of these structures. A challenge has been to identify possible relationships between sites and to place them in their broader landscape setting. The precise spatial scale, relative importance of different factors, and strength of any relationships that contributed to shaping their distributions remain an open question. This paper develops and applies an explicitly spatial framework to address this problem, drawing on a rich body of recent research in Acre state (Brazil) and advanced point process modelling. The analytical approach, which is fully documented and reproducible with the accompanying code, infers the factors affecting earthwork distribution at multiple spatial scales. This enables the first robust predictions of territorial integration in the region, which is discussed context of extant archaeological models. The findings support the interpretation that non-stratified societies occupied likely Acre during the late pre-Columbian period.

scholarly journals Coumarin Derivatives as New Toxic Compounds to Selected K12, R1–R4 E. coli Strains

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2499 ◽  
Author(s):  
Paweł Kowalczyk ◽  
Arleta Madej ◽  
Daniel Paprocki ◽  
Mateusz Szymczak ◽  
Ryszard Ostaszewski
Keyword(s):  
Carboxylic Acid ◽  
Basic Structure ◽  
Biochemical Properties ◽  
The Body ◽  
Hydroxyl Groups ◽  
Coumarin Derivatives ◽  
Antimicrobial Drugs ◽  
High Biological Activity ◽  
E Coli ◽  
And Function

Coumarins are natural compounds that were detected in 80 species of plants. They have numerous applications including the medical, food, tobacco, perfumery, and spirit industries. They show anti-swelling and diastolic effects. However, excess consumption of coumarins may adversely affect our health, because they are easily absorbed from the intestines into the lymph and blood, causing cirrhosis of the liver. Peptidomimetics are molecules whose structure and function are similar to those of peptides. They are an important group of compounds with biological, microbiological, anti-inflammatory, and anti-cancer properties. Therefore, studies on new peptidomimetics, which load the effect of native peptides, whose half-life in the body is much longer due to structural modifications, are extremely important. A preliminary study of coumarin analogues and its derivatives as new potential antimicrobial drugs containing carboxylic acid or ester was performed to determine their basic structure related to their biological features against various types of Gram-stained bacteria by lipopolysaccharide (LPS). We hypothesized that the toxicity (antibacterial activity) of coumarin derivatives is dependent on the of LPS in bacteria and nature and position of the substituent which may be carboxylic acid, hydroxyl groups, or esters. In order to verify this hypothesis, we used K12 (smooth) and R1–R4 (rough) Escherichia coli strains which are characterized by differences in the type of LPS, especially in the O-antigen region, the outermost LPS layer. In our work, we synthesized 17 peptidomimetics containing a coumarin scaffold and checked their influence on K12 and R1–R4 E. coli strains possessing smooth and rough LPS. We also measured the damage of plasmid DNA caused by target compounds. The results of our studies clearly support the conclusion that coumarin peptidomimetics are antagonistic compounds to many of the currently used antibiotics. The high biological activity of the selected coumarin peptidomimetic was associated with identification of the so-called magic methyl groups, which substantially change the biochemical properties of target compounds. Investigating the effects of these compounds is particularly important in the era of increasingly common resistance in bacteria.

Structural similarity of ribosomes from E. coli and A. salina

1978 ◽  
Vol 36 (2) ◽  
pp. 242-243
Author(s):  
M. Boublik ◽  
R.M. Wydro ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Ribosomal Proteins ◽  
Direct Evidence ◽  
Structural Similarity ◽  
Carbon Support ◽  
Artemia Salina ◽  
Uranyl Acetate ◽  
Biological Assays ◽  
E Coli ◽  
And Function ◽  
Fine Carbon

Ribosomes are ribonucleoprotein particles necessary for processing the genetic information of mRNA into proteins. Analogy in composition and function of ribosomes from diverse species, established by biochemical and biological assays, implies their structural similarity. Direct evidence obtained by electron microscopy seems to be of increasing relevance in understanding the structure of ribosomes and the mechanism of their role in protein synthesis.The extent of the structural homology between prokaryotic and eukaryotic ribosomes has been studied on ribosomes of Escherichia coli (E.c.) and Artemia salina (A.s.). Despite the established differences in size and in the amount and proportion of ribosomal proteins and RNAs both types of ribosomes show an overall similarity. The monosomes (stained with 0.5% aqueous uranyl acetate and deposited on a fine carbon support) appear in the electron micrographs as round particles with a diameter of approximately 225Å for the 70S E.c. (Fig. 1) and 260Å for the 80S A.s. monosome (Fig. 2).

Structural Role of rRNAs on the Ribosomal Subunits from E. Coli by Scanning Transmission Electron Microscopy

1981 ◽  
Vol 39 ◽  
pp. 424-425
Author(s):  
M. Boublik ◽  
N. Robakis ◽  
J.S. Wall
Keyword(s):  
Three Dimensional ◽  
Uranyl Acetate ◽  
Dimensional Structure ◽  
Electron Microscopic ◽  
Ribosomal Subunits ◽  
E Coli ◽  
Freeze Dried ◽  
16S Rna ◽  
Scanning Transmission ◽  
And Function

The three-dimensional structure and function of biological supramolecular complexes are, in general, determined and stabilized by conformation and interactions of their macromolecular components. In the case of ribosomes, it has been suggested that one of the functions of ribosomal RNAs is to act as a scaffold maintaining the shape of the ribosomal subunits. In order to investigate this question, we have conducted a comparative TEM and STEM study of the structure of the small 30S subunit of E. coli and its 16S RNA.The conventional electron microscopic imaging of nucleic acids is performed by spreading them in the presence of protein or detergent; the particles are contrasted by electron dense solution (uranyl acetate) or by shadowing with metal (tungsten). By using the STEM on freeze-dried specimens we have avoided the shearing forces of the spreading, and minimized both the collapse of rRNA due to air drying and the loss of resolution due to staining or shadowing. Figure 1, is a conventional (TEM) electron micrograph of 30S E. coli subunits contrasted with uranyl acetate.

Depletion and Reconstitution of Active E. Coli Ribosomes

1975 ◽  
Vol 33 ◽  
pp. 640-641
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Protein Biosynthesis ◽  
Large Subunit ◽  
High Resolution Electron Microscopy ◽  
Small Subunit ◽  
Structure And Function ◽  
Biologically Active ◽  
Biological Macromolecules ◽  
E Coli ◽  
Resolution Electron ◽  
And Function

Correlations between structure and function of biological macromolecules have been studied intensively for many years, mostly by indirect methods. High resolution electron microscopy is a unique tool which can provide such information directly by comparing the conformation of biopolymers in their biologically active and inactive state. We have correlated the structure and function of ribosomes, ribonucleoprotein particles which are the site of protein biosynthesis. 70S E. coli ribosomes, used in this experiment, are composed of two subunits - large (50S) and small (30S). The large subunit consists of 34 proteins and two different ribonucleic acid molecules. The small subunit contains 21 proteins and one RNA molecule. All proteins (with the exception of L7 and L12) are present in one copy per ribosome.This study deals with the changes in the fine structure of E. coli ribosomes depleted of proteins L7 and L12. These proteins are unique in many aspects.

Inhibition of coral settlement at multiple spatial scales by a pervasive algal competitor

2019 ◽  
Vol 612 ◽  
pp. 29-42 ◽  
Author(s):  
NR Evensen ◽  
C Doropoulos ◽  
KM Morrow ◽  
CA Motti ◽  
PJ Mumby
Keyword(s):  
Spatial Scales ◽  
Coral Settlement ◽  
Multiple Spatial Scales

Analysis of the monitoring study of the antibiotic-resistance of the agents of purulent-inflammatory processes of soft tissue

2018 ◽  
Vol 22 (2) ◽  
pp. 285-288
Author(s):  
A.P. Prevar ◽  
A.V. Kryzshanovskaya ◽  
V.A. Radionov ◽  
V.M. Mrug
Keyword(s):  
Soft Tissues ◽  
High Sensitivity ◽  
Biochemical Properties ◽  
Antimicrobial Drugs ◽  
Strict Adherence ◽  
E Coli ◽  
Monitoring Study ◽  
Treatment Measures ◽  
Inflammatory Processes ◽  
Main Factor

The main factor in the treatment of suppurative and inflammatory processes is the timely optimization of treatment measures taking into account the nature of the microflora and its susceptibility to antimicrobial drugs. The purpose of the study is to monitor the spectrum of microorganisms – pathogens of purulent-inflammatory processes of soft tissues in surgical patients; study of the sensitivity of isolated strains to antibiotics. The material was collected in accordance with aseptic rules. The identification of a pure culture of bacteria was carried out according to morphological, culture, biochemical properties, and the presence of virulence enzymes. Sensitivity of bacteria to antibiotics was determined by the standard disks method (by Kirby-Bauer’s). 255 patients with purulent-inflammatory processes of soft tissues were examined for the period from 2014 to 2017. 229 strains of isolated bacteria were included to Escherichia coli, Citrobacer freundii, Enterobacter cloacae, E.aerogenes, Proteus vulgaris, Staphylococcus aureus, S.epidermidis, Streptococcus pyogenes, S.viridians, S.agalactiae, Pseudomonas aeruginosa. The main cause of purulent-inflammatory processes of soft tissues is Staphylococci (67,2%). Compared to previous studies, the number of P.aeruginosa isolated cultures increased (7.9%). In monoculture and in association with other microorganisms, E. coli (9.6% of cases), E.cloacae et aerogenes (3.9% of cases), P.vulgaris (3.9% of cases), C.freundi (2.5% of cases), S.agalactiae, S.pyogenes, S.viridans (3.5%). The number of associated sows reaches 12%. Clinical strains of microorganisms remain most sensitive to fluoroquinolones, cephalosporins, and also retains high sensitivity to gentamicin, lincomycin, rifampicin, which is important for empirical antibiotic therapy. To increase the effectiveness of antibacterial therapy, strict adherence to the mode of appointment of antibiotics, justification of indications, a combination of antibiotics of different spectrum of action, mandatory correction after determining the sensitivity of the pathogen.

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