scholarly journals Ethanolic Extract of Algerian Propolis Induced Cell Damage in Staphylococcus Aureus: A Promising Alternative as a Natural Bio-Preservative in Food Products

2020 ◽  
Vol 49 (4) ◽  
pp. 505-514
Author(s):  
I. K. Bedaida ◽  
S.H.D. Masry ◽  
B. Mamache ◽  
M.G. Shehata ◽  
L. Benammar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Damage ◽  
Ethanolic Extract ◽  
Food Products ◽  
Underlying Mechanism ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Promising Alternative ◽  
Ethanolic Extract Of Propolis ◽  
Scanning Electron

This study describes the antistaphylococcal mechanism of the ethanolic extract of Algerian propolis on Staphylococcus aureus ATCC 25923. To investigate the underlying mechanism of action of the ethanolic extract of propolis, bacteriolysis, bacterial death, leakage of potassium, proteins, nucleic components, and scanning electron microscopic studies were conducted. The results showed that the minimum inhibitory concentration (MIC) of ethanolic extract of propolis against Staphylococcus aureus ATCC 25923 was 39 μg ml–1. The extract displayed significant bactericid activity against S. aureus in a time and concentration dependant manner. Its mode of action was evident from the increase of K+ efflux and nucleotide leakage. These results were confirmed by Scanning Electron Microscopy (SEM) that showed remarkable morphological and ultrastructural changes in S. aureus after exposure to 1MIC and 2MIC concentrations. The overall study contributed to the understanding of the antistaphylococcal mechanism of ethanolic extract of propolis. It emphasizes its potential to be used as an important natural bio-preservatives in food products.

scholarly journals Ultrastructural Characterization of Proteinuric Patients Predicts Clinical Outcomes

2020 ◽  
Vol 31 (4) ◽  
pp. 841-854 ◽  
Author(s):  
Virginie Royal ◽  
Jarcy Zee ◽  
Qian Liu ◽  
Carmen Avila-Casado ◽  
Abigail R. Smith ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cell ◽  
Clinical Outcomes ◽  
Cox Regression ◽  
Cell Damage ◽  
Digital Pathology ◽  
Ultrastructural Changes ◽  
Consensus Clustering ◽  
Electron Microscopic ◽  
Systematic Analysis

BackgroundThe analysis and reporting of glomerular features ascertained by electron microscopy are limited to few parameters with minimal predictive value, despite some contributions to disease diagnoses.MethodsWe investigated the prognostic value of 12 electron microscopy histologic and ultrastructural changes (descriptors) from the Nephrotic Syndrome Study Network (NEPTUNE) Digital Pathology Scoring System. Study pathologists scored 12 descriptors in NEPTUNE renal biopsies from 242 patients with minimal change disease or FSGS, with duplicate readings to evaluate reproducibility. We performed consensus clustering of patients to identify unique electron microscopy profiles. For both individual descriptors and clusters, we used Cox regression models to assess associations with time from biopsy to proteinuria remission and time to a composite progression outcome (≥40% decline in eGFR, with eGFR<60 ml/min per 1.73 m2, or ESKD), and linear mixed models for longitudinal eGFR measures.ResultsIntrarater and interrater reproducibility was >0.60 for 12 out of 12 and seven out of 12 descriptors, respectively. Individual podocyte descriptors such as effacement and microvillous transformation were associated with complete remission, whereas endothelial cell and glomerular basement membrane abnormalities were associated with progression. We identified six descriptor-based clusters with distinct electron microscopy profiles and clinical outcomes. Patients in a cluster with more prominent foot process effacement and microvillous transformation had the highest rates of complete proteinuria remission, whereas patients in clusters with extensive loss of primary processes and endothelial cell damage had the highest rates of the composite progression outcome.ConclusionsSystematic analysis of electron microscopic findings reveals clusters of findings associated with either proteinuria remission or disease progression.

Synergism Between Ethanolic Extract of Propolis (EEP) and Anti-Tuberculosis Drugs on Growth of Mycobacteria

1999 ◽  
Vol 54 (7-8) ◽  
pp. 549-553 ◽  
Author(s):  
Stan Scheller ◽  
Szymon Dworniczak ◽  
Krystian Waldemar-Klimmek ◽  
Marek Rajca ◽  
Anna Tomczyk ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Synergistic Effect ◽  
Bactericidal Activity ◽  
Ethanolic Extract ◽  
Ethanol Extract ◽  
Bacterial Activity ◽  
Active Components ◽  
Wild Strains ◽  
Resistant Strains ◽  
Ethanolic Extract Of Propolis

Abstract Ethanolic extract of propolis exerts a strong anti-bacterial activity, in addition to antifungal. antiviral and antiprotozoal properties. In previous studies from these laboratories we have demonstrated that the intensity of the bactericidal activity of EEP is correlated with the virulence of the mycobacteria tested, and that EEP has a synergistic effect with antibiotics on growth of staphylococcus aureus. In the present study we investigated whether the same synergism and correlation exists between EEP and some anti-tuberculosis drugs on tubercu­losis mycobacteria with different degrees of virulence. Six standard strains and 11 wild strains of mycobacteria were exposed for 30 days to EEP, with or without streptomycin, rifamycin, isoniazid or ethambutol. Out of the 17 strains, 8 were resistant to at least two standard antibiotics, and were considered “multi-resistant strains”. The rest were either susceptible or resistant to only one of the antimycobacterial drugs. Antagonism was recorded only in one case, when Staphylococcus aureus were treated with a mixture of EEP and ethambutol, sug­gesting that a chemical bond could have been formed between this anti-tuberculosis anti­ biotic and one of the active components of the ethanol extract of propolis.

scholarly journals Comparative Study of Corneal Endothelial Cell Damage after Femtosecond Laser Assisted Deep Stromal Dissection

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ting Liu ◽  
Jingjing Zhang ◽  
Dapeng Sun ◽  
Wenjie Sui ◽  
Yangyang Zhang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Cell Damage ◽  
Endothelial Damage ◽  
Lamellar Keratoplasty ◽  
Control Group ◽  
Electron Microscopic ◽  
Anterior Lamellar Keratoplasty ◽  
Bed Thickness ◽  
Scanning Electron

Purpose.To find a relatively safe designed stromal bed thickness to avoid endothelial damage for lamellar keratoplasty with an Allegretto Wavelight FS200 femtosecond laser.Methods.Twelve rabbits were randomly divided into 50 μm and 150 μm groups according to the anticipated residue stromal bed thickness preparation with a femtosecond laser. Six rabbits without laser cutting were used as a control group. Central endothelial images were analyzed with in vivo confocal microscopy and scanning electron microscopy. The apoptosis of endothelium was evaluated with Hoechst 33342 staining and a TUNEL assay.Results.The endothelium of the 50 μm group had extensive injuries upon in vivo confocal and scanning electron microscopic observation, and minor injuries were observed in the 150 μm group. Moreover, more apoptotic cells were observed in the 50 μm group.Conclusions.When using a FS200 femtosecond laser assisted anterior lamellar keratoplasty, there was minor endothelium damage with a 150 μm stromal bed, and a more than 150 μm thickness stromal bed design may prevent the damage of corneal endothelium.

scholarly journals Ultrastructural Changes in Chloroplasts in Harvested Broccoli Flower Buds During Senescence

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 824C-824
Author(s):  
Hirofumi Terai ◽  
Hironobu Tsuchida ◽  
Masashi Mizuno ◽  
Yumi Fukui
Keyword(s):  
Structural Changes ◽  
Optical Microscope ◽  
Ultrastructural Changes ◽  
Scanning Electron Micrographs ◽  
Small Particles ◽  
Flower Buds ◽  
Electron Microscopic ◽  
Green Color ◽  
Polyethylene Bags ◽  
Scanning Electron

Green broccoli (Brassica oleracea L. Italica Group) flower heads were stored in perforated polyethylene bags at 20C. Green color of sepals in broccoli flower buds changed to yellow and individual flower buds wilted gradually during storage. Chlorophyllase activity in flower buds tended to increase and chlorophyll content decreased during senescence. Optical and scanning electron microscopic observations were conducted to elucidate the structural changes of chloroplasts in sepals of broccoli flower buds through the senescence. The chloroplasts observed with optical microscope were fine and green when the stage of broccoli flower buds was all green. However, at half-yellow stage, the shapes of chloroplasts obscured and the green color faded. After this stage, colored small particles appeared in the cells and the number of particles tended to increase as yellowing of the flower buds progressed through the senescence. Scanning electron micrographs indicated that the small particles were formed in the chloroplasts and come out from them with senescence followed by aggregation with each other.

scholarly journals Hormetic Effects of Trifloxystrobin on Aggressiveness of Sclerotinia sclerotiorum

Plant Disease ◽  
2016 ◽  
Vol 100 (10) ◽  
pp. 2113-2118 ◽  
Author(s):  
Ya-Li Di ◽  
Meng-Long Cong ◽  
Ran Zhang ◽  
Fu-Xing Zhu
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Mycelial Growth ◽  
Underlying Mechanism ◽  
Direct Stimulation ◽  
Electron Microscopic ◽  
Disease Symptoms ◽  
Naked Eye ◽  
Quinone Outside Inhibitor ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Sclerotinia sclerotiorum is a devastating ascomycete plant pathogen with an extremely wide host range. Fungicides are still the mainstay for control of this pathogen, and stimulations to mycelial growth and aggressiveness by subtoxic doses of fungicides carbendazim and dimethachlon have been reported. The present study assessed hormetic effects of the quinone outside inhibitor (QoI) fungicide trifloxystrobin on aggressiveness of S. sclerotiorum. Trifloxystrobin at 0.0001, 0.0005, and 0.001 μg/ml exerted significant stimulatory effects on aggressiveness to potted rapeseed plants, and the highest percent stimulation were 20.5 and 24.2% for isolates HB15 and SX11, respectively. At 18 h postinoculation (HPI), initial necrotic lesions were visible to the naked eye on leaves treated with trifloxystrobin, whereas no obvious disease symptoms were discerned for the nontreated control. At 24, 36, and 48 HPI, aggressiveness stimulation was more obvious than at 18 HPI. Scanning electron microscopic observations demonstrated that no mycelia were detected on the nontreated leaves at 4 HPI; by contrast, mycelia were observed on leaves treated with trifloxystrobin at 0.0001 μg/ml. At 8 and 12 HPI, there were more mycelia and infecting hyphae on the treated leaves than on the nontreated control. These results indicated that fungal stimulation had occurred in the first 4 and 8 HPI, suggesting that direct stimulation was likely to be the underlying mechanism for hormetic actions of trifloxystrobin. Pretreatment with trifloxystrobin did not significantly affect subsequent mycelial growth on PDA or aggressiveness to detached rapeseed leaves in the absence of trifloxystrobin. However, in the presence of trifloxystrobin, mycelial growth and aggressiveness were significantly (P < 0.05) greater for the pretreatment with trifloxystrobin at 0.003 and 0.03 μg/ml compared with the nonpretreatment control, indicating that a prior exposure to the fungicide may undermine its subsequent effectiveness. These studies will raise our awareness of fungicide hormesis and have important implications for judicious application of fungicides.

Natural Antimicrobial Agents as an Alternative to Chemical Antimicrobials in the Safety and Preservation of Food Products

2019 ◽  
Vol 13 (1) ◽  
pp. 25-37 ◽  
Author(s):  
Joana Gomes ◽  
Joana Barbosa ◽  
Paula Teixeira
Keyword(s):  
Antimicrobial Activity ◽  
Sodium Chloride ◽  
Sodium Nitrite ◽  
Food Additives ◽  
Ethanolic Extract ◽  
Food Products ◽  
Natural Compounds ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Ethanolic Extract Of Propolis

Background:Microbiological quality of food is of utmost importance in the food industry, so the use of food additives is essential to reduce microbial loads, which may result in food spoilage and poisoning.Objective:This study aimed to test the antimicrobial activity of three natural compounds – chitosan, ethanolic extract of propolis, and nisin – against 15 Gram-positive bacteria, 15 Gram-negative bacteria and two fungi and, also, to compare it with the antimicrobial activity of the chemical compound sodium nitrite, alone and in combination with sodium chloride.Methods:Antimicrobial activity was tested at different pH values and temperatures of incubation to simulate the presence of the pathogens in different food products and different storage conditions, as well as to determine their influence on the inhibition of microorganisms.Results:Most of the Gram-positive bacteria were inhibited at 25 &#181;g/mL of nisin. Concentrations of 10 mg/mL of ethanolic extract of propolis inhibited fungi, most of the Gram-positive and some Gramnegative bacteria, and with concentrations of 0.65% (w/v) of chitosan, it was possible to inhibit most of the tested microorganisms. All the natural compounds tested had greater inhibitory effect against the various microorganisms compared with sodium nitrite alone and in combination with sodium chloride, in the different conditions of pH and temperature.Conclusion:This suggests that natural compounds could be good candidates for use as an alternative to chemical antimicrobials in food safety and preservation.

Correlation between Virulence of Various Strains of Mycobacteria and Their Susceptibility to Ethanolic Extract of Propolis (EEP)

1998 ◽  
Vol 53 (11-12) ◽  
pp. 1040-1044 ◽  
Author(s):  
Stan Scheller ◽  
Henryk Kawalski ◽  
Kazimierz Oklek ◽  
Szymon Dworniczak ◽  
Tetsuya Matsuno ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biological Effects ◽  
Ethanolic Extract ◽  
Bactericidal Effect ◽  
Antifungal Properties ◽  
Virulent Strains ◽  
Ethanolic Extract Of Propolis

Abstract extract of propolis (EEP) has antibacterial, antiviral, antiprotozoal and antifungal properties, in addition to many biological effects. Our laboratory has demonstrated a syner­gistic effect of EEP and antibiotics on the growth of Staphylococcus aureus, and suggested that the bactericidal effect of EEP was expressed mainly on virulent mycobacteria rather than on non-virulent (attenuated) ones. The present study was designed to reconfirm the latter finding, by subjecting 17 different mycobacteria strains to EEP, and evaluating whether there is a correlation between the virulence of the mycobacteria strains studied and their susceptibility to EEP. Our findings demonstrate that while the four non-virulent strains studied are not susceptible to EEP, out of the 13 virulent strains studied seven are susceptible and six are resistant to it. These results suggest that while there is no full correlation between virulence of the mycobacteria tested and their susceptibility to EEP, the few strains that were resistant to EE P were non-virulent.

scholarly journals A study of activity of local alcoholic propolis ointment in the treatment of the external wounds that experimentally infected with staphylococcus aureus in mice

2012 ◽  
Vol 11 (3) ◽  
pp. 15
Author(s):  
A.M. Al-Mohana
Keyword(s):  
Staphylococcus Aureus ◽  
Ethanolic Extract ◽  
Control Group ◽  
Resinous Substance ◽  
Green Color ◽  
Infected Area ◽  
Medicinal Properties ◽  
Dark Green ◽  
Ethanolic Extract Of Propolis ◽  
Dry Substance

Propolis (bee glue) is a sticky, gummy, resinous substance collected by honeybees from variousplant sources, which has various medicinal properties. This study aimed to know the therapeutic roleof ointment which prepared from extract of local propolis in treatment of external wounds thatexperimentally infected with S.aureus in experimental mice. The ratio of ethanolic extract of propolisamounted (33%) of the weight of the dry substance, it was glutinous with dark green color andcharacteristic odor. Moreover, the results of the preliminary chemical tests which was taken in thisstudy revealed that propolis contains flavonoids, resins, terpenes, and phenols.T tested the qualificationof ethanolic extract of propolis In vivo.Through its prepared as an ointment (9%) in the treatment of externalwounds which are induced in a lab. mice infected with S.aureus the ointment showed high qualificationto treat such wounds (8 days ) compared with control group(15 days ) and a group which treated withvaseline (15 days) that is assured by histopathological sections taken from the infected area before andafter treatment.

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