scholarly journals In Vitro Activities of Daptomycin Combined with Fosfomycin or Rifampin on Planktonic and Adherent Linezolid-resistant Enterococcus faecalis

2018 ◽  
Author(s):  
Jin-xin Zheng ◽  
Xiang Sun ◽  
Zhi-wei Lin ◽  
Guo-bin Qi ◽  
Hao-peng Tu ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Adherent Cells ◽  
Planktonic Cells ◽  
Bactericidal Activities ◽  
High Concentrations

AbstractThis study aimed to explore daptomycin combined with fosfomycin or rifampin against the planktonic and adherent linezolid-resistant isolates of Enterococcus faecalis. Four linezolid-resistant isolates of E. faecalis which formed biofilms were collected for this study. Biofilm biomasses were detected by crystal violet staining. The adherent cells in the mature biofilms were counted by CFU numbers and observed by confocal laser scanning microscope (CLSM). In time-killing studies, daptomycin combined with fosfomycin or rifampin (4xMIC) demonstrated bactericidal activities on the planktonic cells, and daptomycin combined with fosfomycin killed more planktonic cells (at least 2-log10 CFU/ml) than daptomycin or fosfomycin alone. Daptomycin alone showed activities against the mature biofilms, and daptomycin combined with fosfomycin (16xMIC) demonstrated significantly more activity than daptomycin or fosfomycin alone against the mature biofilms in three of the four isolates. Daptomycin alone effectively killed the adherent cells, and daptomycin combined with fosfomycin (16xMIC) killed more adherent cells than daptomycin or fosfomycin alone in these mature biofilms. The high concentrations of daptomycin (512 mg/L) combined with fosfomycin indicated more activity than 16xMIC of daptomycin combined with fosfomycin on the adherent cells and the mature biofilms. The addition of rifampin increased the activity of daptomycin against the biofilms and the adherent cells of FB-14 and FB-80 isolates, but was not observed in FB-1 and FB-2 isolates. In conclusion, daptomycin combined with fosfomycin works effectively against the planktonic and adherent linezolid-resistant isolates of E. faecalis. The role of rifampin in these linezolid-resistant isolates is discrepant and needs more studies.

scholarly journals Use of electromagnetic stimulation on an Enterococcus faecalis biofilm on root canal treated teeth in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beatriz H. D. Panariello ◽  
Justin K. Kindler ◽  
Kenneth J. Spolnik ◽  
Ygal Ehrlich ◽  
George J. Eckert ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Laser Scanning ◽  
Confocal Imaging ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Microscopy Imaging ◽  
Electromagnetic Stimulation ◽  
Root Canal Disinfection

AbstractRoot canal disinfection is of utmost importance in the success of the treatment, thus, a novel method for achieving root canal disinfection by electromagnetic waves, creating a synergistic reaction via electric and thermal energy, was created. To study electromagnetic stimulation (EMS) for the disinfection of root canal in vitro, single rooted teeth were instrumented with a 45.05 Wave One Gold reciprocating file. Specimens were sterilized and inoculated with Enterococcus faecalis ATCC 29,212, which grew for 15 days to form an established biofilm. Samples were treated with 6% sodium hypochlorite (NaOCl), 1.5% NaOCl 1.5% NaOCl with EMS, 0.9% saline with EMS or 0.9% saline. After treatments, the colony forming units (CFU) was determined. Data was analyzed by Wilcoxon Rank Sums Test (α = 0.05). One sample per group was scored and split for confocal laser scanning microscopy imaging. There was a significant effect with the use of NaOCl with or without EMS versus 0.9% saline with or without EMS (p = 0.012 and 0.003, respectively). CFUs were lower when using 0.9% saline with EMS versus 0.9% saline alone (p = 0.002). Confocal imaging confirmed CFU findings. EMS with saline has an antibiofilm effect against E. faecalis and can potentially be applied for endodontic disinfection.

scholarly journals Grape Seed Extract as a Potential Remineralizing Agent: A Comparative in vitro Study

2012 ◽  
Vol 13 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Shiny Benjamin ◽  
Roshni LNU ◽  
Sabeena Susan Thomas ◽  
Mohan Thomas Nainan
Keyword(s):  
Laser Scanning ◽  
Grape Seed Extract ◽  
Grape Seed ◽  
Confocal Laser Scanning Microscope ◽  
Seed Extract ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Caries Lesions ◽  
Calcium Glycerophosphate

ABSTRACT Objective Remineralization is an effective treatment that may stop or reverse early tooth decay. Grape seed extract (GSE) is the potential remineralizing agent under investigation. Materials and methods Sound human tooth sections were obtained from the cervical portion of the root and stored in demineralizing solution at 37°C for 96 hours to induce artificial root caries lesions. The sections were divided into four treatment groups including 6.5% grape seed extract, sodium monofluorophosphate (220 ppm) with 0.05% calcium glycerophosphate, 0.5% calcium glycerophosphate and control (no treatment). An in vitro pH cycling model was used to cycle the demineralized specimens through treatment solutions, acidic buffer and neutral buffer for 8 days at 6 cycles per day. Subsequently, they were evaluated using confocal laser scanning microscope. Data were analyzed using analysis of variance (p < 0.05). Results GSE revealed less demineralization and more remineralization compared with other groups. Conclusion GSE promotes remineralization of artificial root caries lesions. Clinical significance The search for the perfect remineralizing agent continues to this day. GSE could be a welcome addition to the remineralization armamentarium. Abbreviations and acronyms GSE: Grape seed extract; ppm: Parts per million; CaGP: Calcium glycerophosphate; CLSM: Confocal laser scanning microscope; ANOVA: Analysis of variance; PA: Proanthocyanidin; CEJ: Cementoenamel junction; mM: Millimole; CaCl2.2H2O: Calcium chloride dihydrate; KH2PO4: Potassium dehydrate phosphate; K2HPO4: Dipotassium phosphate; dH2O: Deionized water; w/v: Weight by volume; ROD: Relative optical density; nm: Nanometer; SD: Standard deviation. How to cite this article Benjamin S, Roshni, Thomas SS, Nainan MT. Grape Seed Extract as a Potential Remineralizing Agent: A Comparative in vitro Study. J Contemp Dent Pract 2012;13(4):425-430.

Synthesis, singlet oxygen generation, photocytotoxicity and subcellular localization of azobisporphyrins as potentially photodynamic therapeutic agents in vitro cell study

2017 ◽  
Vol 21 (02) ◽  
pp. 122-127 ◽  
Author(s):  
Yunman Zheng ◽  
Sizhe Zhu ◽  
Lijun Jiang ◽  
Fengshou Wu ◽  
Chi Huang ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Hela Cells ◽  
Cellular Localization ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Confocal Laser Scanning Microscope ◽  
Confocal Laser ◽  
Oxygen Generation ◽  
Scanning Confocal Microscopy

Three azobisporphyrins (Por1, Por2 and Por3) were synthesized by coupling two molecules of (4-nitrophenyl/pyridyl) porphyrins in the presence of KOH/butanol. The structures of porphyrins were confirmed by UV, IR, NMR and mass spectra and elemental analysis. With tetraphenylporphyrin (H2TPP) as a control, the singlet oxygen (1O[Formula: see text] generation of porphyrins was evaluated through 1,3-diphenylisobenzofuran (DPBF) method. The order of ability to generate 1O2 for three azobisporphyrins was Por 1 [Formula: see text]Por 2 > Por 3[Formula: see text] H2TPP. The photocytotoxicity and sub-cellular localization of azobisporphyrins over Hela cells were studied through MTT analysis and confocal laser scanning microscope, respectively. The results indicated Por 1 and Por 2 displayed the low dark-cytotoxicity, while Por 3 induced a concentration-dependent cytotoxicity to Hela cells with the concentration of porphyrins ranging from 1 to 100 [Formula: see text] M. With the light dose at 4 J/cm2, Por 3 killed more than 60% Hela cells at 2 [Formula: see text] M, indicating a high photocytoxicity. As seen from the laser scanning confocal microscopy images, Por 3 was mainly localized in cell membrane, while Por 1 and Por 2 do not displayed significant fluorescent emission in Hela cells. These results suggest the synthesized cationic azobisporphyrin could be used as a potential therapeutic agent for photodynamic therapy of cancers.

A Facile Synthesis of Acid-Activatable Nanoparticles for Efficient Intracellular Doxorubicin Release

2017 ◽  
Vol 46 ◽  
pp. 20-30 ◽  
Author(s):  
Cao Ming ◽  
Xiao Wan Song ◽  
Yu Jiao Zhang ◽  
Chang Zhi Xu ◽  
Peng Chen ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Hela Cells ◽  
Laser Scanning ◽  
Human Cancer ◽  
Polymeric Nanoparticles ◽  
Confocal Laser Scanning Microscope ◽  
Ph Sensitive ◽  
Confocal Laser ◽  
Cell Nuclei

pH responsive polymeric nanoparticles have emerged as a promising technology platform for targeted and controlled drug delivery in recent years. In this paper, endosomal pH-activatable doxorubicin (DOX) and core-crosslinked polymeric nanoparticles (DCNPs) were prepared and investigated for potent growth inhibition of human cancer cells in vitro. In vitro drug release studies, DOX conjugated nanoparticles with hydrazone bond showed a pH sensitive release phenomenon, that is, the releasing is significantly faster at mildly acidic condition with pH of 5.5 than that at physiological condition. Confocal laser scanning microscope (CLSM) observations revealed that DOX conjugated nanoparticles delivered and released DOX into the cytosols as well as cell nuclei of Hela cells following 6 h incubation. MTT assays demonstrated that these pH-sensitive DOX nanoparticles exhibited high antitumor effect to HeLa cells. The conjugated DOX polymeric nanoparticles may be a promising candidate as a nanoscale and pH-sensitive drug delivery vehicle for cancer therapy.

scholarly journals Antibody response to the 45 kDa Candida albicans antigen in an animal model and potential role of the antigen in adherence

2008 ◽  
Vol 57 (12) ◽  
pp. 1466-1472 ◽  
Author(s):  
Helena Bujdáková ◽  
Ema Paulovičová ◽  
Silvia Borecká-Melkusová ◽  
Juraj Gašperík ◽  
Soňa Kucharíková ◽  
...  
Keyword(s):  
Animal Model ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Vaccine Development ◽  
Laser Scanning Microscopy ◽  
Model Systems ◽  
Confocal Laser

The Candida antigen CR3-RP (complement receptor 3-related protein) is supposed to be a ‘mimicry’ protein because of its ability to bind antibody directed against the α subunit of the mammalian CR3 (CD11b/CD18). This study aimed to (i) investigate the specific humoral isotypic response to immunization with CR3-RP in vivo in a rabbit animal model, and (ii) determine the role of CR3-RP in the adherence of Candida albicans in vitro using the model systems of buccal epithelial cells (BECs) and biofilm formation. The synthetic C. albicans peptide DINGGGATLPQ corresponding to 11 amino-acids of the CR3-RP sequence DINGGGATLPQALXQITGVIT, determined by N-terminal sequencing, was used for immunization of rabbits to obtain polyclonal anti-CR3-PR serum and for subsequent characterization of the humoral isotypic response of rabbits. A significant increase of IgG, IgA and IgM anti-CR3-RP specific antibodies was observed after the third (P<0.01) and the fourth (P<0.001) immunization doses. The elevation of IgA levels suggested peptide immunomodulation of the IgA1 subclass, presumably in coincidence with Candida epithelial adherence. Blocking CR3-RP with polyclonal anti-CR3-RP serum reduced the ability of Candida to adhere to BECs, in comparison with the control, by up to 35 % (P<0.001), and reduced biofilm formation by 28 % (P<0.001), including changes in biofilm thickness and integrity detected by confocal laser scanning microscopy. These properties of CR3-RP suggest that it has potential for future vaccine development.

scholarly journals Mitochondrial function in vitrified versus slow-frozen murine embryos

2019 ◽  
Vol 15 (2) ◽  
pp. 150-152
Author(s):  
Razif Dasiman ◽  
Mimi-Sophia Sarbandi ◽  
Nor-Shahida Abdul Rahman ◽  
Salina Othman ◽  
Mastura Malek ◽  
...  
Keyword(s):  
Mitochondrial Function ◽  
Laser Scanning ◽  
Developmental Stages ◽  
Confocal Laser Scanning Microscope ◽  
Slow Freezing ◽  
Confocal Laser ◽  
Mitochondrial Functions ◽  
Murine Embryos ◽  
Cryopreserved Embryos

The effects of vitrification and slow-freezing on mitochondrial functions of in vitro produced murine embryos at various developmental stages were investigated using the Confocal Laser Scanning Microscope (CLSM). Oocytes were obtained from superovulated females, fertilized with sperm and cultured. Resulting 2-, 4- and 8-cell embryos were collected and cryopreserved by vitrification and slow-freezing. Mitochondria were stained with MitoTracker Red (CMXRos). Images were viewed by CLSM and analyzed using QWin SoftwareV.3. Fluorescent intensities were used to indicate viability. Results showed that mitochondrial fluorescence intensities of cryopreserved embryos were significantly lower as compared to non-cryopreserved embryos (p<0.01). Vitrification was found to be superior to slow-freezing at all developmental stages, based on mitochondrial function.

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