scholarly journals Strain specific motility patterns and surface adhesion of virulent and probiotic Escherichia coli

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
M. M. Abdulkadieva ◽  
E. V. Sysolyatina ◽  
E. V. Vasilieva ◽  
A. I. Gusarov ◽  
P. A. Domnin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Vertical Direction ◽  
Horizontal Layer ◽  
Surface Adhesion ◽  
Near Surface ◽  
Movement Trajectories ◽  
Bacterial Dissemination ◽  
Surface Exploration ◽  
The Individual ◽  
Microfluidic Chambers

AbstractBacterial motility provides the ability for bacterial dissemination and surface exploration, apart from a choice between surface colonisation and further motion. In this study, we characterised the movement trajectories of pathogenic and probiotic Escherichia coli strains (ATCC43890 and M17, respectively) at the landing stage (i.e., leaving the bulk and approaching the surface) and its correlation with adhesion patterns and efficiency. A poorly motile strain JM109 was used as a control. Using specially designed and manufactured microfluidic chambers, we found that the motion behaviour near surfaces drastically varied between the strains, correlating with adhesion patterns. We consider two bacterial strategies for effective surface colonisation: horizontal and vertical, based on the obtained results. The horizontal strategy demonstrated by the M17 strain is characterised by collective directed movements within the horizontal layer during a relatively long period and non-uniform adhesion patterns, suggesting co-dependence of bacteria in the course of adhesion. The vertical strategy demonstrated by the pathogenic ATCC43890 strain implies the individual movement of bacteria mainly in the vertical direction, a faster transition from bulk to near-surface swimming, and independent bacterial behaviour during adhesion, providing a uniform distribution over the surface.

PBP4 and PBP5 are involved in regulating exopolysaccharide synthesis during Escherichia coli biofilm formation

Microbiology ◽  
2021 ◽  
Vol 167 (3) ◽  
Author(s):  
Sathi Mallick ◽  
Shanti Kiran ◽  
Tapas Kumar Maiti ◽  
Anindya S. Ghosh
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Type Species ◽  
Pentose Phosphate ◽  
Bacterial Cells ◽  
Surface Adhesion ◽  
Content Type ◽  
Penicillin Binding Proteins ◽  
E Coli ◽  
Link Type

Escherichia coli low-molecular-mass (LMM) Penicillin-binding proteins (PBPs) help in hydrolysing the peptidoglycan fragments from their cell wall and recycling them back into the growing peptidoglycan matrix, in addition to their reported involvement in biofilm formation. Biofilms are external slime layers of extra-polymeric substances that sessile bacterial cells secrete to form a habitable niche for themselves. Here, we hypothesize the involvement of Escherichia coli LMM PBPs in regulating the nature of exopolysaccharides (EPS) prevailing in its extra-polymeric substances during biofilm formation. Therefore, this study includes the assessment of physiological characteristics of E. coli CS109 LMM PBP deletion mutants to address biofilm formation abilities, viability and surface adhesion. Finally, EPS from parent CS109 and its ΔPBP4 and ΔPBP5 mutants were purified and analysed for sugars present. Deletions of LMM PBP reduced biofilm formation, bacterial adhesion and their viability in biofilms. Deletions also diminished EPS production by ΔPBP4 and ΔPBP5 mutants, purification of which suggested an increased overall negative charge compared with their parent. Also, EPS analyses from both mutants revealed the appearance of an unusual sugar, xylose, that was absent in CS109. Accordingly, the reason for reduced biofilm formation in LMM PBP mutants may be speculated as the subsequent production of xylitol and a hindrance in the standard flow of the pentose phosphate pathway.

scholarly journals Cytotoxic and Apoptotic Effects of Recombinant Subtilase Cytotoxin Variants of Shiga Toxin-Producing Escherichia coli

2015 ◽  
Vol 83 (6) ◽  
pp. 2338-2349 ◽  
Author(s):  
J. Funk ◽  
N. Biber ◽  
M. Schneider ◽  
E. Hauser ◽  
S. Enzenmüller ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Vero Cells ◽  
Toxic Activity ◽  
Content Type ◽  
B Subunits ◽  
Induced Apoptosis ◽  
The Individual ◽  
Apoptotic Effects ◽  
Subtilase Cytotoxin

In this study, the cytotoxicity of the recently described subtilase variant SubAB2-2of Shiga toxin-producingEscherichia coliwas determined and compared to the plasmid-encoded SubAB1and the chromosome-encoded SubAB2-1variant. The genes for the respective enzymatic active (A) subunits and binding (B) subunits of the subtilase toxins were amplified and cloned. The recombinant toxin subunits were expressed and purified. Their cytotoxicity on Vero cells was measured for the single A and B subunits, as well as for mixtures of both, to analyze whether hybrids with toxic activity can be identified. The results demonstrated that all three SubAB variants are toxic for Vero cells. However, the values for the 50% cytotoxic dose (CD50) differ for the individual variants. Highest cytotoxicity was shown for SubAB1. Moreover, hybrids of subunits from different subtilase toxins can be obtained which cause substantial cytotoxicity to Vero cells after mixing the A and B subunits prior to application to the cells, which is characteristic for binary toxins. Furthermore, higher concentrations of the enzymatic subunit SubA1exhibited cytotoxic effects in the absence of the respective B1subunit. A more detailed investigation in the human HeLa cell line revealed that SubA1alone induced apoptosis, while the B1subunit alone did not induce cell death.

scholarly journals Molecular Characterization of Two Lactate Dehydrogenase Genes with a Novel Structural Organization on the Genome of Lactobacillus sp. Strain MONT4

2004 ◽  
Vol 70 (10) ◽  
pp. 6290-6295 ◽  
Author(s):  
Jennifer Weekes ◽  
Gülhan Ü. Yüksel
Keyword(s):  
Escherichia Coli ◽  
Lactate Dehydrogenase ◽  
Sequence Analysis ◽  
Molecular Characterization ◽  
Northern Blot ◽  
Structural Organization ◽  
Genomic Organization ◽  
The Individual

ABSTRACT Two lactate dehydrogenase (ldh) genes from Lactobacillus sp. strain MONT4 were cloned by complementation in Escherichia coli DC1368 (ldh pfl) and were sequenced. The sequence analysis revealed a novel genomic organization of the ldh genes. Subcloning of the individual ldh genes and their Northern blot analyses indicated that the genes are monocistronic.

scholarly journals Determination of the united quality latent index of adaptability (UQLIA) and contribution of some environmental parameters to it for Deschampsia antarctica populations, Galindez island (Maritime Antarctic) season 2017/2018

2019 ◽  
Vol 16 (2) ◽  
pp. 190-202
Author(s):  
I. Y. Parnikoza ◽  
N. Y. Miryuta ◽  
V. Y. Ivanets ◽  
E. O. Dykyi
Keyword(s):  
Surface Temperature ◽  
Pairwise Comparison ◽  
Environmental Parameters ◽  
Soil Surface ◽  
Deschampsia Antarctica ◽  
Near Surface ◽  
Soil Surface Temperature ◽  
Experimental Populations ◽  
The Individual

The purpose of our work has been to determine the indicator of complex adaptability — the United Quality Latent Index of Adaptability (UQLIA) for the experimental populations of Deschampsia antarctica É. Desv. and study the contribution to it of some environmental factors such as the near soil surface temperature and organogens content. Materials and methods. The determination of UQLIA was based on a pairwise comparison of the differences between investigated parameters of populations by mathematical regression techniques. The soil surface temperature was measured by loggers installed near plants in each locus during April 2017 – April 2018. Results and conclusions. Temperature fluctuations were described during December 2017 – February 2018 for twelve experimental populations of D. antarctica and one control fragment of moss turf subformation from Galindez Island. Significant variations in average daily near surface temperature were observed during the study period between populations, especially in December and January. The UQLIA of D. antarctica for this season was calculated on the basis of the projective cover, biometric indices of generative plants and the content of protective and reserve proteins in seeds for the eleven populations. The values of the United Soil Surface Temperature Influence Index (UTII) for the season summer months and the United Organogens Content in Soil Influence Index (UOCSII) have been calculated for the individual parameters of D. antarctica plants adaptability. The reliable contribution of UTII to ULIA has been shown for December and January, at the moment of the greatest variation of soil surface temperature. UOCSII provided a reliable contribution to the ULIA only in the amount of UTII. Keywords: Deschampsia antarctica, United Quality Latent Index of Adaptability (UQLIA), contribution of soil surface temperature and organogens content to complex adaptability.

Expression of bacterial Rubisco genes in Escherichia coli

1986 ◽  
Vol 313 (1162) ◽  
pp. 433-445 ◽  
Keyword(s):  
Escherichia Coli ◽  
Rhodospirillum Rubrum ◽  
Active Form ◽  
Amino Acid Residues ◽  
Structural Genes ◽  
Physico Chemical ◽  
Chemical Studies ◽  
The Individual ◽  
Very High

The structural genes for three forms of Rubisco have been isolated from bacteria and introduced into various plasmids. Apart from details of the sequences which have been obtained from these constructs, they are now being exploited for mutagenesis to determine the identity and specific function of the individual amino acid residues that compose the active site. These methods have been applied to a plasmid that contains the structural gene for the simplest form of Rubisco from Rhodospirillum rubrum to obtain mutant enzymes with altered activity. The construct pRR2119 is also expressed to very high levels in Escherichia coli and enough recombinant protein of both the wild-type and m utant enzymes can be obtained for detailed physico-chemical studies. Other vectors have now been constructed, containing the genes of prokaryotic Rubisco that assemble into an active form I enzyme. The levels of expression are acceptable and the product is similar to the authentic enzyme. These constructs are now being used for mutagenesis in vitro to attempt to alter the relative rates of the oxygenase and carboxylase activities.

Dielectric barrier discharge (DBD) plasma pretreatment of lignocellulosic materials in air at atmospheric pressure for their improved wettability: a literature review

Holzforschung ◽  
2018 ◽  
Vol 72 (11) ◽  
pp. 979-991 ◽  
Author(s):  
Jure Žigon ◽  
Marko Petrič ◽  
Sebastian Dahle
Keyword(s):  
Literature Review ◽  
Atmospheric Pressure ◽  
Dielectric Barrier Discharges ◽  
Surface Adhesion ◽  
Dbd Plasma ◽  
Adhesion Properties ◽  
Dielectric Barrier ◽  
Plasma Pretreatment ◽  
The Individual ◽  
Barrier Discharges

AbstractThe treatment of wood surfaces with gas discharges is one of the methods to achieve better surface adhesion properties. Good penetration, spreading and wettability of the applied liquid adhesives and coatings is a crucial factor for their adequate mechanical properties. Plasmas are the result of electrical discharge and can be created in different ways. The plasma treatment (PT) is frequently executed prior to material bonding or coating via the so-called dielectric barrier discharges (DBD) at atmospheric pressure. This literature review summarizes the essential aspects of DBD PTs aiming at a better wettability and surface adhesion. After introduction of the principle of DBD, the individual effects of internal and external parameters of the process will be discussed, which influence the final properties of treated materials.

scholarly journals Driving the paradigm shift of near surface exploration geochemistry using ultrafine soils

2019 ◽  
Vol 2019 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Ryan Noble ◽  
Ian Lau ◽  
Tenten Pinchand ◽  
Ravi Anand ◽  
Paul Morris
Keyword(s):  
Paradigm Shift ◽  
Near Surface ◽  
Exploration Geochemistry ◽  
Surface Exploration

scholarly journals Longitudinal Study of Shiga Toxin-Producing Escherichia coli Shedding in Sheep Feces: Persistence of Specific Clones in Sheep Flocks

2009 ◽  
Vol 75 (6) ◽  
pp. 1769-1773 ◽  
Author(s):  
Sergio Sánchez ◽  
Remigio Martínez ◽  
Alfredo García ◽  
Jorge Blanco ◽  
Jesús E. Blanco ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Longitudinal Study ◽  
Shiga Toxin ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Individual Animal ◽  
Pulsed Field ◽  
The Individual ◽  
Sheep Feces

ABSTRACT To provide information on the persistence and maintenance of colonization with Shiga toxin-producing Escherichia coli (STEC) in sheep, pulsed-field gel electrophoresis analysis of STEC isolates (n = 145) belonging to serogroups O5, O91, and O146 from 39 healthy animals was performed in a 12-month longitudinal study carried out with four sheep flocks. At the flock level as well as the individual-animal level, the same clones were obtained on sampling occasions separated by as much as 11 months.

scholarly journals A Comparative Study of the Adherent-Invasive Escherichia coli Population and Gut Microbiota of Healthy Vegans versus Omnivores

2020 ◽  
Vol 8 (8) ◽  
pp. 1165
Author(s):  
Rebecca Veca ◽  
Christian O’Dea ◽  
Jarred Burke ◽  
Eva Hatje ◽  
Anna Kuballa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gut Microbiota ◽  
Random Amplified Polymorphic Dna ◽  
Fecal Microbiota ◽  
Vegan Diet ◽  
Rrna Gene ◽  
E Coli ◽  
Abundance And Diversity ◽  
The Individual ◽  
Diversity Profiles

Adherent-invasive Escherichia coli (AIEC) strains carry virulence genes (VGs) which are rarely found in strains other than E. coli. These strains are abundantly found in gut mucosa of patients with inflammatory bowel disease (IBD); however, it is not clear whether their prevalence in the gut is affected by the diet of the individual. Therefore, in this study, we compared the population structure of E. coli and the prevalence of AIEC as well as the composition of gut microbiota in fecal samples of healthy participants (n = 61) on either a vegan (n = 34) or omnivore (n = 27) diet to determine whether diet is associated with the presence of AIEC. From each participant, 28 colonies of E. coli were typed using Random Amplified Polymorphic DNA (RAPD)–PCR. A representative of each common type within an individual was tested for the presence of six AIEC-associated VGs. Whole genomic DNA of the gut microbiota was also analyzed for its diversity profiles, utilizing the V5-V6 region of the16S rRNA gene sequence. There were no significant differences in the abundance and diversity of E. coli between the two diet groups. The occurrence of AIEC-associated VGs was also similar among the two groups. However, the diversity of fecal microbiota in vegans was generally higher than omnivores, with Prevotella and Bacteroides dominant in both groups. Whilst 88 microbial taxa were present in both diet groups, 28 taxa were unique to vegans, compared to seven unique taxa in the omnivores. Our results indicate that a vegan diet may not affect the number and diversity of E. coli populations and AIEC prevalence compared to omnivores. The dominance of Prevotella and Bacteroides among omnivores might be accounted for the effect of diet in these groups.

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