scholarly journals Viability and phenotypic heterogeneity of Rhodococcus Rhodochrous CNMN-AC-05 in the presence of fullerene C60

2021 ◽  
Vol 2 (3) ◽  
pp. 4-9
Author(s):  
Olga POSTOLACHI ◽  
Inna RASTIMESINA ◽  
Valentina JOSAN
Keyword(s):  
Toxic Effect ◽  
Fullerene C60 ◽  
Optimum Concentration ◽  
Morphological Features ◽  
Bacterial Cells ◽  
Rhodococcus Rhodochrous ◽  
Microbiological Method ◽  
Total Inhibition ◽  
Colony Forming Units ◽  
Object Of Study

Introduction. In recent years, due to wide applications of nanotechnologies in various fields, the safety of nanomaterials has become a pressing issue. Fullerene C60 is not an exception. Research on the activity of microorganisms and their interaction with nanoparticles is of major importance, both for microorganisms and for the ecosystem as a whole. Material and methods. Fullerene C60 powder was purchased from Sigma-Aldrich. The object of study was R. rhodochrous CNMN-Ac-05 strain. The number of viable bacterial cells was estimated by colony-forming units (CFU). The morphological features of the rhodococci colonies have been described according to the usual microbiological method. Results. It was established that fullerene C60 in concentrations of 1-25 mg/L fullerene C60 stimulated the growth of R. rhodochrous by 2.4-2.8 times. As the concentration of fullerene C60 increased up to 50-100 mg/L, the multiplication and growth of rhodococci decreased by 29.5% and 38% respectively. In the presence of 1-10 mg/L fullerene C60 the rhodococci population remained homogeneous, being composed of 100% S type colonies. The increase of fullerene C60 concentration led both to the decrease in the CFU number and to the appearance of R type colonies, up to 1.3% of population. Conclusions. Fullerene C60 in concentrations 1-100 mg/L had no obvious toxic effect on the rhodococci strain. The optimum concentration is 10 mg/L. The concentrations higher than 25 mg/L led to the dissociation of rhodococcal population and diminution in the CFU counts, but not to the total inhibition.

Toxic Effect of 2-ethyl (bicyclo[2.2.1] heptane) on Bacterial Cells

2019 ◽  
Vol 35 (6) ◽  
pp. 67-72 ◽  
Author(s):  
I.V. Manukhov ◽  
L.S. Yaguzhinsky ◽  
M.V. Bermeshev ◽  
M.A. Zisman ◽  
V.G. Pevgov ◽  
...  
Keyword(s):  
Toxic Effect ◽  
Atmospheric Oxygen ◽  
Inducible Promoter ◽  
Oxygen Species ◽  
Bacterial Cells ◽  
Unique Identifier ◽  
E Coli ◽  
Lux Biosensors ◽  
High Level ◽  
Ministry Of Higher Education

Toxic effect of 2-ethylnorbornane (2-ethyl(bicyclo[2.2.1]heptane) (EBH)) on bacteria has been studied using the E. coli pRecA-lux and E. coli pKatG- lux cells as lux-biosensors. It was shown that the addition of EBH to the incubation medium leads to death and growth retardation, high level oxidative stress and DNA damage in E. coli cells. It is assumed that the oxidation of EBH with atmospheric oxygen causes the formation of reactive oxygen species in the medium, which makes a major contribution to the toxicity of this substance. biosensor, luciferase, bioluminescence, inducible promoter, PrecA, PkatG The authors are grateful to Stanislav Filippovich Chalkin for the development of interdisciplinary ties in the scientific community. The work was financially supported by the Ministry of Higher Education and Science of Russia (Project Unique Identifier RFMEFI60417X0181, Agreement No. 14.604.21.0181 of 26.09.2017).

scholarly journals Bacterial EPS as a mediator of calcium carbonate morphology and polymorphism

2008 ◽  
Vol 72 (1) ◽  
pp. 291-291 ◽  
Author(s):  
J. Tourney ◽  
B. T. Ngwenya
Keyword(s):  
Calcium Carbonate ◽  
Early Life ◽  
Morphological Features ◽  
Precipitation Process ◽  
Bacterial Cells ◽  
Geological Record ◽  
Close Proximity ◽  
Distinguishing Features

Biologically influenced mineralization either on the surfaces of, or in close proximity to bacterial cells may produce minerals that display distinct mineralogical or morphological features as a consequence of the microbial influence on the precipitation process. Characterizing such distinguishing features could potentially facilitate identification of early life in the geological record.

Influence of Resin Monomers on Growth of Oral Streptococci

2004 ◽  
Vol 83 (4) ◽  
pp. 302-306 ◽  
Author(s):  
Y. Takahashi ◽  
S. Imazato ◽  
R.R.B. Russell ◽  
Y. Noiri ◽  
S. Ebisu
Keyword(s):  
Morphological Observation ◽  
Bacterial Suspension ◽  
Bacterial Cells ◽  
Oral Streptococci ◽  
Streptococcus Sobrinus ◽  
Associated Bacteria ◽  
Streptococcus Sanguis ◽  
Colony Forming Units ◽  
Biomass Increase

Ethyleneglycol dimethacrylate monomers have been previously reported to stimulate the growth of certain caries-associated bacteria on the basis of turbidity measurements. To elucidate the detail of this effect, we examined the influence of resin monomers on the growth of Streptococcus sobrinus and Streptococcus sanguis by determination of bacterial numbers (colony-forming units), morphological observation, and chemical analysis. Although the absorbance values in the stationary phase of bacterial suspension were increased in the presence of ethyleneglycol monomers, no significant differences were observed for bacterial numbers throughout the incubation period. Scanning electron microscopy observation revealed the formation of sparse vesicular material surrounding bacterial cells when incubated with ethyleneglycol monomers, and these products were proved to be resin polymers. The results demonstrate that the apparent biomass increase during incubation with ethyleneglycol monomers is due not to promotion of bacterial multiplication, but to the polymerization of resin monomers to form vesicular structures attached to cells.

scholarly journals The Effect of Corticotropin on Mouse Spleen Colony-forming Cells

Blood ◽  
1974 ◽  
Vol 44 (3) ◽  
pp. 393-398 ◽  
Author(s):  
Robert E. Reed
Keyword(s):  
Stem Cell ◽  
Cell Differentiation ◽  
Toxic Effect ◽  
Steroid Hormones ◽  
Marked Decrease ◽  
Stem Cell Differentiation ◽  
Mouse Spleen ◽  
Hypoxic Exposure ◽  
Direct Toxic Effect ◽  
Colony Forming Units

Abstract Several investigators have reported a reduction in the number of colony-forming units (CFU) in the spleens of mice exposed to hypoxia and have postulated that this is secondary to a direct toxic effect of hypoxemia on the CFU. To test the hypothesis that at least part of this effect could be secondary to the stress of the hypoxic exposure, mice were given 12 consecutive daily injections of corticotropin (ACTH), and the number of spleen and marrow CFU were assayed by the spleen colony technique. There was a marked decrease in spleen CFU in these mice when compared with control animals, but marrow CFU were not reduced. These tesults indicate that part of the effect of hypoxemia on CFU may be secondary to the stress of the exposure and suggest that spleen CFU are sensitive to steroid hormones. Further investigation of this and other differences between spleen and marrow CFU could lead to a better understanding of stem cell differentiation.

scholarly journals Xanthine Oxidase of the Clothes Moth, Tineola Bisselliella, and Some Other Insects

1955 ◽  
Vol 8 (3) ◽  
pp. 369 ◽  
Author(s):  
H Irzykiewicz
Keyword(s):  
Methylene Blue ◽  
Uric Acid ◽  
Toxic Effect ◽  
Xanthine Oxidase ◽  
Oxidase Activity ◽  
Acid Production ◽  
Fat Body ◽  
Optimum Concentration ◽  
Optimum Ph ◽  
Wet Weight

Xanthine oxidase activity in Tineola larvae averages 200� /!moles of uric acid per g whole larva (wet weight) per hr and in Tenebrio, Lucilia, Anthrenocerus, Ephestia, and Anthrenus larvae activity ranges between 13�4 and 1�3. The optimum pH for Tineola xanthine oxidase lies between pH 7�7 and 8� 0, and the optimum concentration of xanthine is at or below 1�3 X 10-3M. Methylene blue in concentrations up to 5�3 X 1O-3M has no toxic effect on this enzyme, and the lower concentrations of methylene blue have a limiting effect. Cyanide and 6-pteridyl aldehyde inhibit Tineola xanthine oxidase. The insect xanthine oxidases are demonstrated to be dehydrogenases. DPN, and pyruvate and DPN together, stimulate uric acid production by Tineola xanthine oxidase in the absence of methylene blue. In Tenebrio larvae there is a higher concentration of xanthine oxidase in the midgut and fat-body than in the remaining tissues.

In-vitro Comparative Assessment of Antibacterial and Anti-adherent Effect of Two Types of Surface Modificants on Stainless Steel Orthodontic Brackets Against Streptococcus mutans

2021 ◽  
pp. 030157422110372
Author(s):  
Mrunmaye Math ◽  
Alok G. Shah ◽  
Parag Gangurde ◽  
Anita G. Karandikar ◽  
Anjali Gheware ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Surface Modification ◽  
Streptococcus Mutans ◽  
Rf Magnetron Sputtering ◽  
Orthodontic Brackets ◽  
P Value ◽  
Bacterial Cells ◽  
Colony Forming Units ◽  
Surface Modified

Objective: Comparative evaluation of antibacterial and anti-adherent properties of surface-modified stainless steel (SS) orthodontic brackets against Streptococcus mutans ( S. mutans). Materials and Methods: The study was conducted on 120 SS orthodontic McLaughlin, Bennett, Trevisi (MBT) 0.022″ slot by Leone, Italy. Orthodontic brackets that constituted the sample size were divided into 6 groups, consisting of 20 samples each in two control (non-surface coated) and four experimental groups. The experimental group’s surface coatings were photocatalytic zinc oxide (ZnO) and photocatalytic titanium oxide (TiO2), which were carried out by radiofrequency (RF) magnetron sputtering method for surface modification. Brackets were subjected to microbiological tests against S. mutans. For anti-adherence, weight change, pre- and postexposure, was evaluated to gauge the adherence of bacteria and colony-forming units/milliliter (CFU/mL) count measuring the survival rate of bacterial cells for antibacterial activity. Results: The TiO2-coated group showed statistically significant anti-adherence ( P-value < .05) against S. mutans than control and ZnO groups. The CFU count of TiO2 group was lower than control as well as ZnO group. Conclusion: TiO2 is superior to ZnO and should be continued to be considered for surface modification of orthodontic brackets against White Spot Lesions (WSLs) and gingivitis.

scholarly journals High Potential of Bacterial Adhesion on Block Bone Graft Materials

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2102 ◽  
Author(s):  
Themistoklis Nisyrios ◽  
Lamprini Karygianni ◽  
Tobias Fretwurst ◽  
Katja Nelson ◽  
Elmar Hellwig ◽  
...  
Keyword(s):  
Bone Graft ◽  
Bacterial Adhesion ◽  
Bacterial Species ◽  
Bacterial Cells ◽  
E Coli ◽  
Colony Forming Units ◽  
Initial Adhesion ◽  
Bone Grafting Materials ◽  
Graft Removal ◽  
Block Bone Graft

Bone graft infections represent a challenge in daily clinics, resulting in increased patient discomfort and graft removal. The aim of this study was to investigate the initial adhesion of five representative pathogens on three different block bone graft materials (xenogeneic, alloplastic and allogeneic) and to assess if chlorhexidine (CHX) can effectively control the initial bacterial adhesion. Three different block bone grafting materials (Tutobone®, Endobon® and human spongiosa) were incubated with Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis and Pseudomonas aeruginosa in the presence or absence of 0.2% CHX solution. Bacterial adhesion was assessed by the direct counting of the colony-forming units (CFUs) and visualized by scanning electron microscopy (SEM). Overall, the selected bacterial species adhered successfully to all tested bone replacement scaffolds, which showed similar bacterial counts. The lg CFU values ranged from 5.29 ± 0.14 to 5.48 ± 0.72 for E. coli, from 4.37 ± 0.62 to 5.02 ± 0.48 for S. aureus, from 4.92 ± 0.34 to 4.95 ± 0.21 for S. mutans, from 4.97 ± 0.40 to 5.22 ± 0.13 for E. faecalis and from 4.23 ± 0.54 to 4.58 ± 0.26 for P. aeruginosa. CHX did not interfere with initial microbial adhesion, and yet it killed all adhered bacterial cells. Thus, CHX can be used to prevent subsequent biofilm infections.

Toxic effect of Aβ25–35 and fullerene C60 on erythrocytes

2008 ◽  
Vol 35 (4) ◽  
pp. 436-440 ◽  
Author(s):  
I. N. Solomadin ◽  
N. V. Marov ◽  
N. I. Venediktova ◽  
E. A. Kosenko ◽  
Yu. G. Kaminsky
Keyword(s):  
Toxic Effect ◽  
Fullerene C60

scholarly journals Evaluating the toxic effect of an antimicrobial agent on single bacterial cells with optical tweezers

2014 ◽  
Vol 6 (1) ◽  
pp. 112 ◽  
Author(s):  
Akbar Samadi ◽  
Chensong Zhang ◽  
Joseph Chen ◽  
S. N. S. Reihani ◽  
Zhigang Chen
Keyword(s):  
Antimicrobial Agent ◽  
Toxic Effect ◽  
Optical Tweezers ◽  
Bacterial Cells

scholarly journals New Intracanal Formulations Containing Doxycycline or Chlorhexidine Against Enterococcus faecalis

2014 ◽  
Vol 15 (1) ◽  
pp. 61-65
Author(s):  
Shelon Cristina Souza Pinto ◽  
Ana Rita Marques da Silva ◽  
Elizabete Brasil dos Santos ◽  
Fábio André dos Santos ◽  
Paulo Vitor Farago ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Antimicrobial Effect ◽  
Conventional Technique ◽  
Negative Control ◽  
Bacterial Cells ◽  
Root Canals ◽  
Colony Forming Units ◽  
Root Canal System ◽  
Initial Contamination

ABSTRACT The present study aims to evaluate the antimicrobial effect of two new intracanal preparations against E. faecalis. Thirty single-rooted human canine teeth were used. The crowns were removed and the roots were instrumented using a conventional technique. Three groups of ten teeth each were infected with 108 CFU/ ml of E. faecalis for 21 days. The root canals were filled with new intracanal medications containing 3% doxycycline hydrochloride (DX) or 2% chlorhexidine digluconate (CHX). Ten teeth received no medication (NM)-negative control. Microbial samples were obtained 21 days after contamination: 14 days under the effect of the intracanal medications and 7 days after replacing the medications by BHI broth. The samples were homogenized, diluted, seeded on BHI agar and incubated for 48h/36°C. The number of colony forming units (CFU/ml) was obtained and analyzed statistically. All intracanal dressings significantly reduced the number of bacterial cells in the root canal after 14 days with medication. After the period with 7 days with BHI broth, the CFU counts of E. faecalis remained at low values. However, the NM group showed a significant increase of CFU in this period to similar values of the initial contamination. 3% doxycycline hydrochloride gel and 2% CHX gel were effective to eliminate E. faecalis from the root canal system. How to cite this article da Silva ARM, Pinto SCS, dos Santos EB, dos Santos FA, Farago PV, Gomes JC, Pina-Vaz I, Carvalho MF. New Intracanal Formulations Containing Doxycycline or Chlorhexidine Against Enterococcus faecalis. J Contemp Dent Pract 2014;15(1):61-65.

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