scholarly journals Regulation of Recombination betweengtfB/gtfCGenes inStreptococcus mutansby Recombinase A

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Satoko Inagaki ◽  
Kazuyo Fujita ◽  
Yukiko Takashima ◽  
Kayoko Nagayama ◽  
Arifah C. Ardin ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Streptococcus Mutans ◽  
Reca Protein ◽  
Cellular Adhesion ◽  
Colony Morphology ◽  
Biological Functions ◽  
Clinical Strains ◽  
Cooperative Action

Streptococcus mutansproduces 3 types of glucosyltransferases (GTFs), whose cooperative action is essential for cellular adhesion. The recombinase A (RecA) protein is required for homologous recombination. In our previous study, we isolated several strains with a smooth colony morphology and low GTF activity, characteristics speculated to be derived from the GTF fusions. The purpose of the present study was to investigate the mechanism of those fusions.S. mutansstrain MT8148 was grown in the presence of recombinant RecA (rRecA) protein, after which smooth colonies were isolated. The biological functions and sequences of thegtfBandgtfCgenes of this as well as other clinical strains were determined. The sucrose-dependent adherence rates of those strains were reduced as compared to that of MT8148. Determination of the sequences of thegtfBandgtfCgenes showed that an approximately 3500 bp region was deleted from the area between them. Furthermore, expression of therecAgene was elevated in those strains as compared to MT8148. These results suggest that RecA has an important role in fusions ofgtfBandgtfCgenes, leading to alteration of colony morphology and reduction in sucrose-dependent adhesion.

Methods for the Determination of the Purity of Exosomes

2020 ◽  
Vol 25 (42) ◽  
pp. 4464-4485 ◽  
Author(s):  
Katarzyna Kluszczyńska ◽  
Liliana Czernek ◽  
Wojciech Cypryk ◽  
Łukasz Pęczek ◽  
Markus Düchler
Keyword(s):  
Drug Transport ◽  
Biological Fluids ◽  
Drug Carriers ◽  
Biological Functions ◽  
Isolation And Purification ◽  
Pubmed Database ◽  
High Concentrations ◽  
Targeted Release

Background: Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance. Methods: Articles describing the isolation and purification of exosomes were retrieved from the PubMed database. Results: Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols. Conclusion: Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.

scholarly journals STUDY OF ANTI-VIRUS ACTIONS OF METABOLITES OF LACTOBACTERIA

2020 ◽  
Vol 73 (7) ◽  
pp. 1484-1488
Author(s):  
Svetlana V. Kalinichenko ◽  
Kristina V. Melentyevа ◽  
Hans Manee ◽  
Natalia V. Dubinina ◽  
Natalia V. Zvereva ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Antiviral Activity ◽  
Cell Cultures ◽  
Lactobacillus Rhamnosus ◽  
Culture Fluid ◽  
Probiotic Strain ◽  
Maximum Tolerated Dose ◽  
Clinical Strains ◽  
Coxsackie B

The aim: of the work was to study the antiviral activity of the metabolites of the probiotic strain Lactobacillus rhamnosus GG (LGG or ATCC 53103) regarding clinical strains of enteroviruses (Coxsackie B-5, ECNO21) isolated from the feces of intestinal infections. Materials and methods: The object of the study was substrate-dependent cell cultures of HeLa, Vero, Hep-2 lines. The titer of the virus was determined by the presence of a clear cytopathic action (CPA) in the monolayer infected cells of the virus. Results: Determination of the enteric virus infections activity in the culture fluid showed that in samples with the LGG metabolites, the infections activity of the clinical strains of enteroviruses decreased after 24 hours, at 1.5-1.7 (p <0.05) times, and after 96 hours in 3, 6 – 5,7 times (p <0,01). the processing of cell cultures by metabolites in the amount of 0.3 mg / ml contributed to a decrease in the titer of viruses by 2.77 ± 0.11 lg TCDD50 / cm3, 2.83 ± 0.11 lg TCD50 / cm3 and 2.94 ± 0.13 lg TCD50 / cm3 for Vero, HeLa and Hep-2 line cells in 24 hours. Conclusions: It has been experimentally determined that the maximum tolerated dose (MTD) of L. rhamnosus GG metabolites was 0.3 μg / ml for all cultures of cell lines. Determination of the antiviral activity of L. rhamnosus GG metabolites in clinical viruses of enteroviruses (Coxsackie B-5 and ECNO-21) showed a decrease in infection activity in 1.5-1.7 times, (p <0.05) of clinical trials in clinical trials enteroviruses.

scholarly journals Immunochemical, biochemical and pathogenic properties of fluidal and intermediate strains of Clavibacter michiganensis subsp. sepedonicus

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 291-293
Author(s):  
B. Kokošková ◽  
R. Jeřabková
Keyword(s):  
Monoclonal Antibodies ◽  
Metabolic Activity ◽  
Species Level ◽  
Colony Morphology ◽  
Clavibacter Michiganensis ◽  
Clavibacter Michiganensis Subsp ◽  
Ring Rot ◽  
Atypical Cells ◽  
Das Elisa

Clavibacter michiganensis subsp. sepedonicus (Cms), causing ring rot of potato, is a quarantine bacterium. According to colony morphology, Cms occurs mostly as fluidal (smooth), but sometime as intermediate (rough, i.e. less fluidal) variants, too. Commercial monoclonal antibodies (Agdia, USA) were used for determination of 40 Cms strains representing both forms. All Cms strains were reliably identified by IFAS, but atypical cells were sometime recorded in population of intermediate strains. The fluidal Cms strains were more reliably identified using DAS-ELISA and the Biolog GP MicroPlate System<sup>TM</sup> than intermediate strains. The intermediate Cms strains had decreased metabolic activity compared with fluidal strains and that is why they were identified only to the genera or to the species level or not identified. The differences among fluidal and intermediate Cms strains were recorded also in bioassay on eggplants. The intermediate Cms strains caused atypical or no symptoms with comparison to fluidal strains.

scholarly journals Analysis of Loci Required for Determination of Serotype Antigenicity in Streptococcus mutans and Its Clinical Utilization

2003 ◽  
Vol 41 (9) ◽  
pp. 4107-4112 ◽  
Author(s):  
Y. Shibata ◽  
K. Ozaki ◽  
M. Seki ◽  
T. Kawato ◽  
H. Tanaka ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Clinical Utilization

scholarly journals The enhancing antibiofilm activity of curcumin on Streptococcus mutans strains from severe early childhood caries

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Bingchun Li ◽  
Ting Pan ◽  
Huancai Lin ◽  
Yan Zhou
Keyword(s):  
Early Childhood ◽  
Streptococcus Mutans ◽  
Early Childhood Caries ◽  
Antibiofilm Activity ◽  
Curcumin Treatment ◽  
Clinical Strains ◽  
Live Bacteria ◽  
Total Bacteria ◽  
Severe Early Childhood Caries ◽  
Childhood Caries

Abstract Background Streptococcus mutans (S. mutans) is one of the main cariogenic bacteria for caries. It was found that the clinical strains of S. mutans isolated from caries active population have stronger cariogenic ability than the isolates from caries-free (CF) people. Previous studies have found that curcumin can inhibit biofilm formation of S. mutans UA159. The objective of this study is to explore the antibiofilm effect of curcumin on the clinical isolates of S. mutans from severe early childhood caries(SECC). Results The isolates from SECC group had more biomass than CF group (t = 4.296, P < 0.001). The acidogenicity and aciduricity of the strains from two groups showed no significant difference. After treatment with curcumin, the viability of biofilm was reduced to 61.865% ± 7.108% in SECC and to 84.059% ± 10.227% in CF group at 24 h (P < 0.05). The net reduction of live bacteria and total bacteria in the SECC group was significantly higher than that of the CF group (live bacteria t = 3.305, P = 0.016; total bacteria t = 2.378, P = 0.045) at 5 min. For 24 h, the net reduction of live bacteria and total bacteria in the SECC group was significantly higher than that of the CF group (live bacteria t = 3.305, P = 0.016; total bacteria t = 2.378, P = 0.045). The reduction of biofilm thickness reduced significantly in 5 min (t = 4.110, P = 0.015) and in 24 h (t = 3.453, P = 0.014). Long-term (24 h) curcumin treatment inhibited the amount of EPS in SECC group from (25.980 ± 1.156) μm3/μm2 to (20.136 ± 1.042) μm3/μm2, the difference was statistically significant (t = 7.510, P < 0.001). The gene of gtfC, gtfD, ftf, gbpB, fruA and srtA in the CF group and the gtfB, gtfC, gtfD, ftf, gbpB, srtA in SECC group were respectively reduced after 5 min curcumin treatment. After 24 h treatment, the gtfB, gtfC, gtfD, ftf, gbpB, fruA and srtA in both two groups were downregulation, all the differences were statistically significant. Conclusions Curcumin has antibiofilm activity on clinical strains of S. mutans, especially for those isolated from SECC.

scholarly journals The usefulness of biotyping in the determination of selected pathogenicity determinants in Streptococcus mutans

2014 ◽  
Vol 14 (1) ◽  
pp. 194 ◽  
Author(s):  
Wirginia Krzyściak ◽  
Katarzyna K Pluskwa ◽  
Jakub Piątkowski ◽  
Paweł Krzyściak ◽  
Anna Jurczak ◽  
...  
Keyword(s):  
Streptococcus Mutans

scholarly journals Recombination Can either Help Maintain Very Short Telomeres or Generate Longer Telomeres in Yeast Cells with Weak Telomerase Activity

2011 ◽  
Vol 10 (8) ◽  
pp. 1131-1142 ◽  
Author(s):  
Evelina Basenko ◽  
Zeki Topcu ◽  
Michael J. McEachern
Keyword(s):  
Homologous Recombination ◽  
Telomere Length ◽  
Telomerase Activity ◽  
Telomere Maintenance ◽  
Yeast Cells ◽  
Colony Morphology ◽  
Wild Type ◽  
Telomeric Repeats ◽  
Yeast Mutants ◽  
Derivatives Of

ABSTRACT Yeast mutants lacking telomerase are able to elongate their telomeres through processes involving homologous recombination. In this study, we investigated telomeric recombination in several mutants that normally maintain very short telomeres due to the presence of a partially functional telomerase. The abnormal colony morphology present in some mutants was correlated with especially short average telomere length and with a requirement for RAD52 for indefinite growth. Better-growing derivatives of some of the mutants were occasionally observed and were found to have substantially elongated telomeres. These telomeres were composed of alternating patterns of mutationally tagged telomeric repeats and wild-type repeats, an outcome consistent with amplification occurring via recombination rather than telomerase. Our results suggest that recombination at telomeres can produce two distinct outcomes in the mutants we studied. In occasional cells, recombination generates substantially longer telomeres, apparently through the roll-and-spread mechanism. However, in most cells, recombination appears limited to helping to maintain very short telomeres. The latter outcome likely represents a simplified form of recombinational telomere maintenance that is independent of the generation and copying of telomeric circles.

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