scholarly journals Carbohydrate utilization of Erwinia amylovora in vitro

2004 ◽  
Vol 10 (2) ◽  
Author(s):  
M. Hevesi ◽  
A. Farkas ◽  
A. Kása ◽  
Zs. Orosz-Kovács
Keyword(s):  
Sugar Content ◽  
Fruit Trees ◽  
Sugar Concentration ◽  
Bacterial Cells ◽  
Pome Fruit ◽  
Carbohydrate Utilization ◽  
Free Moisture ◽  
High Concentrations

Nectar is a multi-component aqueous solution that promotes bacterial multiplication. The concentration of nectar in plant flowers is not stable since it is under the influence of environmental conditions, especially free moisture and relative humidity. Experiments were conducted with "artificial nectar" and directed along two lines: (1) determination of the optimal concentrations of carbohydrates for the growth of E. amylovora development (2) consumption of different carbohydrates besides basic sugars. Solutions of "artificial nectar" were prepared in different compositions by changing the dominance of basic sugars (fructose — glucose —sucrose) in proportions of 2:1:1, 1:2:1, 1:1:2 and between concentrations of 10-0.6% (diluted with Basal minimum broth) in order to determine optimal conditions for the development of E. amylovora. At a basic sugar concentration of 10% bacterial multiplication started and continued until I log degree (from 106 to 107 cfu/ml). At concentrations of 5% and 2,5 % cells developed with nearly the same kinetics (from 106 to 8x107 cfu/ml and from 106 to 9x107 cfu/ml, respectively). Multiplication was more pronounced and nearly the same at concentrations of 1.2 % and 0.6 % (from106 to 2x108 cfu/ml). At a basic sugar concentration 30% total sugars bacterial multiplication did not occur, while at 20 % it was negligible, not measurable photometrically. At minimal concentrations of F, G, S (between 1-0.1 %) bacterial cells were still able to multiply, producing organic acids from sugars. Our study showed that E. amylovora requires only a small amount of sugars (0.1%) for multiplication (acid production) while high concentrations inhibit multiplication. There was a negative correlation between sugar content and cell density. The optimal range of sugar concentration was at about 1%. Effect of "less frequent carbohydrates" to E. amylovora multiplication was also determined using the API 50 CH strip. We could provide information on utilization of 39 carbohydrates by the bacterium at different categories as follows: Not utilized-, Slowly and weakly utilized-, Slowly and completely utilized-, Quickly and completely utilized carbohydrates. We suppose that carbohydrates that belong to the latter two groups could play an important role as nectar components in promoting E. amylovora multiplication in the blossoms of pome fruit trees.

scholarly journals Quantifying fluorescent glycan uptake to elucidate strain-level variability in foraging behaviors of rumen bacteria

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Leeann Klassen ◽  
Greta Reintjes ◽  
Jeffrey P. Tingley ◽  
Darryl R. Jones ◽  
Jan-Hendrik Hehemann ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Ex Vivo ◽  
Rapid Assessment ◽  
Vital Role ◽  
Strain Level ◽  
Metabolic Phenotype ◽  
Specific Cell ◽  
Bacterial Cells ◽  
Carbohydrate Utilization

AbstractGut microbiomes, such as the microbial community that colonizes the rumen, have vast catabolic potential and play a vital role in host health and nutrition. By expanding our understanding of metabolic pathways in these ecosystems, we will garner foundational information for manipulating microbiome structure and function to influence host physiology. Currently, our knowledge of metabolic pathways relies heavily on inferences derived from metagenomics or culturing bacteria in vitro. However, novel approaches targeting specific cell physiologies can illuminate the functional potential encoded within microbial (meta)genomes to provide accurate assessments of metabolic abilities. Using fluorescently labeled polysaccharides, we visualized carbohydrate metabolism performed by single bacterial cells in a complex rumen sample, enabling a rapid assessment of their metabolic phenotype. Specifically, we identified bovine-adapted strains of Bacteroides thetaiotaomicron that metabolized yeast mannan in the rumen microbiome ex vivo and discerned the mechanistic differences between two distinct carbohydrate foraging behaviors, referred to as “medium grower” and “high grower.” Using comparative whole-genome sequencing, RNA-seq, and carbohydrate-active enzyme fingerprinting, we could elucidate the strain-level variability in carbohydrate utilization systems of the two foraging behaviors to help predict individual strategies of nutrient acquisition. Here, we present a multi-faceted study using complimentary next-generation physiology and “omics” approaches to characterize microbial adaptation to a prebiotic in the rumen ecosystem.

scholarly journals In Vitro Evaluation of Five Antimicrobial Peptides against the Plant Pathogen Erwinia amylovora

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 554
Author(s):  
Rafael J. Mendes ◽  
Laura Regalado ◽  
João P. Luz ◽  
Natália Tassi ◽  
Cátia Teixeira ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Antimicrobial Peptides ◽  
Erwinia Amylovora ◽  
Growth Curves ◽  
Fruit Trees ◽  
Membrane Permeabilization ◽  
Control Measures ◽  
Minimal Bactericidal Concentration ◽  
Pome Fruit

Fire blight is a major pome fruit trees disease that is caused by the quarantine phytopathogenic Erwinia amylovora, leading to major losses, namely, in pear and apple productions. Nevertheless, no effective sustainable control treatments and measures have yet been disclosed. In that regard, antimicrobial peptides (AMPs) have been proposed as an alternative biomolecule against pathogens but some of those AMPs have yet to be tested against E. amylovora. In this study, the potential of five AMPs (RW-BP100, CA-M, 3.1, D4E1, and Dhvar-5) together with BP100, were assessed to control E. amylovora. Antibiograms, minimal inhibitory, and bactericidal concentrations (minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC), growth and IC50 were determined and membrane permeabilization capacity was evaluated by flow cytometry analysis and colony-forming units (CFUs) plate counting. For the tested AMPs, the higher inhibitory and bactericidal capacity was observed for RW-BP100 and CA-M (5 and 5–8 µM, respectively for both MIC and MBC), whilst for IC50 RW-BP100 presented higher efficiency (2.8 to 3.5 µM). Growth curves for the first concentrations bellow MIC showed that these AMPs delayed E. amylovora growth. Flow cytometry disclosed faster membrane permeabilization for CA-M. These results highlight the potential of RW-BP100 and CA-M AMPs as sustainable control measures against E. amylovora.

Attachment of Salmonella to mammalian cells in vitro

1983 ◽  
Vol 29 (12) ◽  
pp. 1731-1735 ◽  
Author(s):  
Clifford S. Mintz ◽  
Dean O. Cliver ◽  
R. H. Deibel
Keyword(s):  
Cell Lines ◽  
Mammalian Cells ◽  
Culture Cell ◽  
Intestinal Cell ◽  
Tissue Culture Cell ◽  
Bacterial Cells ◽  
Intestinal Cell Line ◽  
Hela Cell Lines ◽  
High Concentrations

The attachment of Salmonella typhimurium strain PHL67342 to several mammalian tissue culture cell lines was investigated. Strain PHL67342 failed to attach in significant numbers to the Buffalo green monkey (BGM), swine testicular (ST), and HeLa cell lines. Significant attachment was observed with the Henle intestinal cell line. Log-phase cells of strain PHL67342 attached in greatest numbers to the Henle cells after 45 min of incubation at 37 °C. Attachment to the Henle cells was not affected by D-mannose or D-galactose, but was markedly inhibited by high concentrations of alpha-methyl-D-mannoside. Also, Salmonella lipopolysaccharide had no effect on the attachment of strain PHL67342 to the Henle cells. Fimbriae were not detected on the bacterial cells used in the adherence experiments. These results suggest that some bacterial factor(s) other than fimbriae and lipopolysaccharide mediate the attachment of strain PHL67342 to the Henle cells.

scholarly journals Ketamine used in the therapy of depressive disorders impacts protein profile, proliferation rate and phagocytosis resistance of enterococci

2021 ◽  
Author(s):  
Tomasz Artur Jarzembowski ◽  
Agnieszka Daca ◽  
Wiesław J. Cubała ◽  
Marek Bronk ◽  
Łukasz Naumiuk
Keyword(s):  
Depressive Disorders ◽  
Early Stage ◽  
Protein Profile ◽  
Proliferation Rate ◽  
Bacterial Suspension ◽  
Bacterial Cells ◽  
High Concentrations ◽  
Etiological Agents ◽  
Different Response

Abstract Background: Ketamine is known to cause rapid anti-depressive effect. Additionally, it has been also proved that at high concentrations ketamine inhibits bacterial growth. It is also widely known that even sub-inhibitory concentration of chemicals, as concentration of ketamine used in therapy of depression, may change bacterial properties, including their virulence. The knowledge about possible influence of ketamine on bacterial commensals seems to be essential, as the mechanism of ketamine’s action in depression is believed to result also from its’ anti-inflammatory activity. In the current study we aimed to evaluate the in vitro influence of ketamine on proliferation rate, phagocytosis resistance and toxicity of enterococci. Results: The studied enterococcal strains were isolated as etiological agents of infection and collected in the Department of Medical Microbiology, Medical University of Gdansk. To measure metabolic activity of Enterococcus faecalis 10µM of CFDA-SE was added to bacterial suspension. The number of bacterial cells and fluorescence of particles were determined using FACSVerse flow cytometer. Additionally, for the determination of phagocytosis resistance, THP-1 human monocytes cell line from ATCC was used. Suspension of monocytes which engulfed bacteria was then stained with propidium iodide to determine cells’ membrane permeability and to evaluate cytotoxicity of enterococci. The result of the study proved diverse influence of therapeutic concentration of ketamine on Enterococci. In 23.1% of strains both proliferation rate and metabolism activity were inhibited. This group of strains was more susceptible to phagocytosis and had lower cytotoxicity than in culture without ketamine. Different response of isolates to ketamine was also visible in changes of protein profile determined by MALDI TOF. Conclusions: The analysis of bacteria at early stage of growth curve demonstrate the bacterial diversity in response to ketamine and let us set the hypothesis that microbiome susceptibility to ketamine may be one of the elements which should be taken into consideration when planning the successful pharmacotherapy of depression.

scholarly journals In vivo capture of bacterial cells by remote guiding

2021 ◽  
Author(s):  
Iaroslav A. Rybkin ◽  
Sergey I. Pinyaev ◽  
Olga A. Sindeeva ◽  
Sergey V. German ◽  
Maja Koblar ◽  
...  
Keyword(s):  
Genetic Material ◽  
Local Concentration ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Toxic Side Effect ◽  
High Concentrations ◽  
Strong Barrier ◽  
Growth Distribution

Recently, it has been shown that several bacterial strains can be very efficient in cancer treatment since they possess many important properties such as self-targeting, ease of detection, sensing and toxicity against tumors. However, there are only a few relevant candidates for such an approach, as targeting and detection one of the biggest challenges as well as there are many limitations in the use of genetic approaches. Here, it is proposed the solution that enables surface modification of alive bacterial cells without interfering with their genetic material and potentially reduces their toxic side effect. By the electrostatic interaction fluorescently labeled polyelectrolytes (PEs) and magnetite nanoparticles (NPs) were deposited on the bacterial cell surface to control the cell growth, distribution and detection of bacteria. According to the results obtained in vivo, by the magnet entrapment of the modified bacteria the local concentration of the cells was increased more than 5 times, keeping the high concentrations even when the magnet is removed. Since the PEs create a strong barrier, in vitro it was shown that the division time of the cells can be regulated for better immune presentation.

scholarly journals Effect of Commonly Prescribed Liquid Medications on Streptococcus mutans Biofilm. An in vitro study

2017 ◽  
Vol 41 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Samantha A Clark ◽  
LaQuia A Vinson ◽  
George Eckert ◽  
Richard L Gregory
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Fungal Infections ◽  
Sugar Content ◽  
In Vitro Study ◽  
Flat Bottom ◽  
Microtiter Plates ◽  
Oral Liquid ◽  
High Concentrations

Objective: This study addressed the effect of pediatric liquid antibiotic medications on Streptococcus mutans UA159. These suspensions commonly contain sugars such as sucrose to make them more palatable for children. The study was designed to evaluate the effects of oral liquid antibiotics on Streptococcus mutans growth and biofilm formation. Study Design: A 24 hour culture of S. mutans was treated with various concentrations of liquid medications commonly prescribed to children for odontogenic or fungal infections– amoxicillin, penicillin VK, clindamycin, and nystatin. The study was conducted in sterile 96-well flat bottom microtiter plates. The minimum inhibitory and biofilm inhibitory concentrations (MIC/MBIC) of S. mutans were determined for each medication. S. mutans was cultured with and without the test drugs, the amount of total growth measured, the biofilms washed, fixed, and stained with crystal violet. The absorbance was determined to evaluate biofilm formation. Results: Higher concentrations of amoxicillin, penicillin VK and clindamycin had decreased biofilm and overall growth than the control. The MICs were 1:2,560 (1.95 ug/ml), 1:2,560 (1.95 ug/ml) and 1:40 (9.375 ug/ml), while the MBIC were 1:640 (7.8 ug/ml), 1:1,280 (3.9 ug/ml) and 1:20 (18.75 ug/ml), respectively. Lower concentrations provided increased biofilm and overall growth. Nystatin induced significantly more biofilm and overall growth than the control at all concentrations. Conclusion: At high concentrations, approximately at the levels expected to be present in the oral cavity of children, amoxicillin, penicillin, and clindamycin inhibited S. mutans biofilm and overall growth due to their antibiotic activity, while at lower concentrations the three antibiotics demonstrated an increase in biofilm and growth. The increase in S. mutans biofilm and overall growth is most likely attributed to the sugar content in the medications. Nystatin provided an increase in biofilm and growth at each concentration tested.

scholarly journals A study of the antioxidative behavior of phenolic acids, in aqueous herb extracts, using a dsDNA biosensor

2012 ◽  
Vol 10 (4) ◽  
pp. 1280-1289 ◽  
Author(s):  
Elina Skeva ◽  
Stella Girousi
Keyword(s):  
Phenolic Acids ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Deposition Potential ◽  
Dna Biosensors ◽  
High Concentrations ◽  
Vitro Analysis ◽  
Herb Extracts

AbstractElectrochemical DNA biosensors are promising tools for the fast, inexpensive and simple in vitro analysis for the determination of free radicals and antioxidants. High concentrations of antioxidants in such compounds as phenolic acids and plant extracts, act as free radical terminators which reduce the effect of the oxidative dam-age on DNA. The electrochemical behavior of three representative phenolic acids, caffeic acid, gallic acid and trolox were studied by cyclic voltammetry. Moreover, the determination of the above antioxidants under the optimized conditions (scan rate, deposition potential and time) using differential pulse voltammetry was also investigated. In vitro studies focused on their antioxidative effect were performed by adsorptive transfer stripping voltammetry and dsDNA biosensor. Using Fenton’s system, with FeSO4 and H2O2 was chosen as a strong oxidative system. This biosensor was applied as a screening antioxidant test in order to estimate the antioxidant capacity of aqueous herb extracts.

Effect of low fibrinogen concentrations on the rheology of human blood in vitro

1979 ◽  
Vol 236 (3) ◽  
pp. H447-H450
Author(s):  
W. Blattler ◽  
P. W. Straub ◽  
C. Jeanneret ◽  
G. S. Horak
Keyword(s):  
Human Blood ◽  
Cell Aggregation ◽  
Fibrinogen Concentration ◽  
Shear Rates ◽  
Red Blood Cell Aggregation ◽  
Low Concentrations ◽  
Normal Human ◽  
High Concentrations

The influence of low concentrations of fibrinogen on the rheology of normal human blood was investigated with an instrument that permitted simultaneous determination of viscosity and the state of red blood cell aggregation and deformation. Fibrinogen, in concentrations of 9-82 mg/100 ml, decreased blood viscosity at all shear rates below the value obtained with red blood cells suspended in serum. At concentrations above 116 mg/100 ml viscosity was increased. Aggregate formation increased progressively as the fibrinogen concentration increased, necessitating higher dispersing shear rates. The deformation and alignment of the red cells, occurring at a shear rate of 230 s-1, was facilitated by low concentrations. The effect of fibrinogen on low-shear viscosity is explained by the formation of different kinds of aggregates. At low concentrations, the aggregates consist of only few cells forming spherelike particles displaying hemodynamic properties better than those of the single discoid cells. At normal or high concentrations big rodlike aggregates occur and increase resistance to flow.

Comparative evaluation of fifteen anti-sickling agents

Blood ◽  
1983 ◽  
Vol 61 (4) ◽  
pp. 693-704 ◽  
Author(s):  
H Chang ◽  
SM Ewert ◽  
RM Bookchin ◽  
RL Nagel
Keyword(s):  
Nitrogen Mustard ◽  
Potent Inhibitor ◽  
Oxygen Affinity ◽  
Red Cell ◽  
Red Cell Indices ◽  
Oxygen Affinity Of Hemoglobin ◽  
High Concentrations ◽  
Further Development

Abstract Fifteen compounds reported to be inhibitors of gelation or sickling were studied by standard methods. These tests included (1) the determination of the solubility of deoxyhemoglobin S or Csat, (2) evaluation of sickling in whole SS blood at various pO2s, (3) measurement of the oxygen affinity of hemoglobin and blood, and (4) examination of red cell indices and morphology. Among the 4 noncovalent agents tested, butylurea was the most potent inhibitor of gelation and sickling in vitro; however, relatively high concentrations were required compared to the covalent agents. In the latter group, bis-(3,5 dibromosalicyl)-fumarate, nitrogen mustard, and dimethyladipimidate were especially effective inhibitors of gelation and/or sickling. All of these compounds require further development before they can be considered for clinical use.

scholarly journals Comparative Study Regarding in Vitro Infections with Erwinia Amylovora and Pseudomonas Syringae Pv. Syringae on Pomaceae Species

2015 ◽  
Vol 48 (1) ◽  
pp. 97-106
Author(s):  
Irina Paraschiva Chiriac ◽  
Fl. D. Lipşa ◽  
E. Ulea
Keyword(s):  
Pseudomonas Syringae ◽  
Erwinia Amylovora ◽  
Plant Protection ◽  
Fruit Trees ◽  
Pome Fruit ◽  
Occurrence Time ◽  
Major Objective ◽  
Great Economic Importance ◽  
In Vitro Inoculation

Abstract The knowledge about pome fruit trees bacterioses and their evolution in orchards is a major objective for plant protection. Erwinia amylovora and Pseudomonas syringae pv. syringae cause on attacked organs of Pomaceae species similar dieback symptoms in vegetative and flowering shoots of quince, pear and apple in spring. Both bacteria can produce disastrous diseases in orchards and are therefore of great economic importance. Biological materials represented by vegetative shoots, leaves and fruits of Pyrus spp., Malus spp., Cydonia spp. were used after isolation of different E. amylovora and Ps. syringae pv. syringae strains for in vitro infections. Results presented in this study established that for in vitro inoculation of Pomaceae species similar symptoms in case of leaves and, respectively different symptoms for vegetative shoots and fruits occurred. The occurrence time was the only difference, because Ps. syringae pv. syringae spread faster than E. amylovora. The vegetative shoots inoculated with E. amylovora, in comparison to Ps. syringae pv. syringae, were more damaged and for both bacteria the highest values for attack degree were recorded in case of pear species, followed by quince and apples, respectively.

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