Efficacy of Ozonated Water Against Erwinia carotovora subsp. carotovora in Brassica campestris ssp. chinensis

Erwinia carotovora subsp. carotovora (Ecc) is a bacterial pathogen that causes decay of vegetables and is found in a wide range of Brassica crops in the Shanghai area, particularly in non-heading Chinese cabbage (NHCC). In this study, aqueous ozone was used as an antimicrobial agent to prevent the growth of Ecc bacterial colonies. Ecc that were treated with aqueous ozone were completely inactivated after the bacteria had been exposed to 0.5 mg/L ozone at 28 °C. Furthermore, a susceptible NHCC cultivar was directly sprayed with different concentrations of dissolved ozonated water as a pesticide substitute. The effects of the treatments on morphology were analyzed, and some treatments were characterized by induction of visible symptoms of senescence. No negative effects were observed after treatment by spraying ozonated water compared with the control at concentrations below 8 mg/L. However, visible damage to leaves was observed after the plants were exposed to 10 mg/L ozonated water via spraying for 15 days during the plant reproductive stage. Additionally, enzyme activities and antioxidant responses gradually increased to a certain degree and then decreased in the untreated and ozonated water-treated plants. These results showed that ozonated water was effective in restraining pathogens and potentially defending against disease in growing NHCC plants within a certain concentration range. These results provide a theoretical basis for preventing disease by applying ozonated water to vegetables as an alternative to pesticides.     

Disinfection of Dental Instruments Contaminated with Streptococcus mutans Using Ozonated Water Alone or Combined with Ultrasound

Ozone gas diluted in water has been shown to produce significant results in terms of the elimination of microorganisms. Streptococcus mutans is the etiologic agent of dental caries. Methods using water containing ozone and an ultrasonic cleaner were employed for the disinfection of a curette. Streptococcus mutans was grown in a selective medium. The curette was submitted to disinfection by water containing ozone, by ultrasound, and then both techniques were combined. The results show that either method produced a significant microbial reduction, but the efficacy of both methods combined was greater. This method of disinfection proved to be both viable and cheap.     

Ozonated Olive Oil with a High Peroxide Value for Topical Applications: In-Vitro Cytotoxicity Analysis with L929 Cells

Previous studies have shown that ozonated vegetable oils have been used topically for healing of cutenous wounds. The aim of this study is to evaluate the dose dependent use of ozonated olive oil with high peroxide value (OZ) on the viability of cells for preventing side effects in topical applications. To the best of our knowledge, there are no reports investigaing the effect of peroxide value of ozonated olive oil associated with its cytotoxic activity on mouse non-neoplastc fibroblast cell lines (L929). Therefore, the present study was carried out by using OZ alone and/or in combination with glycerol and olive oil. In our study OZ was prepared by using pure olive oil. Both olive oil and glycerol are non-toxic and can be mixed with OZ uniformly. The cytotoxic activity of samples against L929 fibroblasts was assessed using the tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assay. The peroxide value of synthesized OZ was found to be in the range of 2700–2900 mEq O₂/kg oil. The OZ/olive oil group did not show any cell death at all concentrations tested (p > 0.05) however OZ/glycerol group showed statistically significant reductions in viability at higher concentrations (p = 0.004–0.006) compared to the control group. Conclusively, using OZ/olive oil with a peroxide value of 2700–2900 mEq O₂/kg oil for short-term incubation was non-cytotoxic to the L929 fibroblast cell line.     

Potential of Ozonated Water at Different Temperatures to Improve Safety and Shelf-Life of Fresh Cut Lettuce

The present study was carried out to determine the effect of ozonated water (2 mg L^?1) at different temperatures (4 °C and 15 °C) on the microbiological, color and sensory properties of lettuce. Cold ozone treatment (4 °C) significantly reduced the natural background microflora of lettuce. Salmonella Typhimurium and Escherichia coli inoculated on lettuce samples were insignificantly influenced by the temperature of water. During storage period at +4 °C for 14 days, the highest quality was observed from the samples treated with cold ozonated water. Ozone treatments did not affect the color properties and sensory quality of lettuce samples.     

Industrial-scale Malting Barley (Hordeum vulgare L.) Seed Disinfection by Fog of Ozonated Water Application

The aim of this study was to underscore that seed treatment by the fog of ozonated water constitutes a promising alternative tool, in terms of health and environmental gains, regarding traditional ozone treatment. In order to obtain a clear vision of this performance, the technology was implemented on an industrial scale (malting industry). Under an exposition of barley seeds to 9.8 ppm of dissolved ozone into water, our results showed a significant disinfection effect of 80% for Fusarium sp. and 70% for Aspergillus sp., but no effect was established on Alternaria sp.     

Antibacterial effect of dental cements evaluated using agar diffusion test

Purpose: Secondary caries can occur around the restoration, fixed prosthesis, and orthodontic band margins because of cariogenic bacteria. Long-lasting antibacterial effectiveness of dental cements used contemporarily can reduce this phenomenon. The purpose of this study was to examine the antibacterial activities of nine dental cements (BisCem^®, Super-Bond C&B, Rely X^TM, Panavia^TM F 2.0, Variolink^® II, Unitek^TM Multi Cure, Multilink^® Automix, Clearfil^TM Esthetic Cement, Transbond^TM LR) using agar diffusion test. Materials and methods: The test materials were inserted into the wells of Muller Hinton agar plates inoculated with Streptococcus mutans and Streptococcus salivarious. The diameters of the inhibition zones produced around the materials were measured after 24 h of incubation. Two-Way ANOVA, the Kruskal-Wallis, and the Mann–Whitney U tests at a significance level of p < 0.05 were analyzed for the results. Results: Unitek Multi Cure cement exhibited a significant difference from the control group against both S. mutans and S. salivarious (p < 0.05). While the zone of inhibition of Unitek Multi Cure cement was shorter (8.50 ± 1.77) than the control group (12.63 ± 1.30), Unitek Multi Cure had antibacterial effect against S. mutans and S. salivarious (p < 0.05). S. mutans displayed a significantly lower resistance to Unitek Multi Cure, BisCem, and Superbond C&B than S. salivarious (p < 0.05). Conclusion: Conventional glass ionomer cement, Unitek Multi Cure, exhibited greatest in vitro antibacterial activity against both S. mutans and S. salivarious. Formation of dental caries had been suppressed by the fluoride-releasing GICs.     

Antimicrobial Activity of Ozone against Pathogenic Oral Microorganisms on Different Denture Base Resins

ABSTRACT

The present study aimed to evaluate the antimicrobial effect of gaseous ozone against specific oral pathogens on denture base resins. 1080 round samples were prepared (10mm-diameter, 2mm-thickness). Candida albicans, Streptococcus mutans, Streptococcus gordonii, and Aggregatibacter actinomycetemcomitans, polyamide-Deflex, heat-cured polymethyl-methacrylate (PMMA)-QC-20, and cold-cured-PMMA-Meliodent. The doses and durations: 25, 50 and 100µg/ml, 5, 10, 20, 30 minutes. For Cell viability (CV) MTT was used. 100µg/ml was most effective dose for C. albicans, S .gordonii, and A. actinomycetemcomitans were in heat-cured-PMMA and polyamide for S.mutans. For polyamide, lowest CV was 43% in S.mutans and A.actinomycetemcomitans. CV of heat-cure and cold-cure PMMA were 31% and 32% in S.gordonii, respectively. CV was similar for all resins and durations in S.mutans and A.actinomycetemcomitans and for polyamide for C.albicans and for heat-cure PMMA for S.gordonii. 30-min ozone application killed 80% of all microorganisms in all resins except for C.albicans in polyamide (65% cell death) and cold-cure PMMA (57% cell death). Optimal dose/duration combination was 100 µg/ml-10 min. Gaseous ozone can be considered as an effective cleansing agent for denture base resins.     

Effect of Ozonated Water Treatment on Fatty Acid Composition and Some Quality Parameters of Olive Oil

The organic olives from Çine-Ayd?n (Turkey) were washed with tap or ozonated water for 2 and 5 min, respectively, and pressed to olive oil. The effects of wash treatments on fatty acid composition and several quality parameters of the oils were determined. The maximum values after 2-min ozonated water washes were 9.58 meqO₂/kg, 0.73%, 2.44 and 0.16 for peroxide, free acid, K₂₃₂ and K₂₇₀ values, respectively, which were under the standard limits for extra-virgin olive oil. Five min of ozonated water washes also yielded acceptable results, except for a slight excess on K₂₃₂ value. Ozonated water washes had almost no effect on fatty acid composition.     

Are antibacterial component additions in etchants and adhesives effective against Streptococcus Mutans?

The aim was to investigate the antibacterial activity of various acids and adhesives with and without antibacterial components against Streptococcus mutans. The antibacterial activities of 35% phosphoric acid (Ultra-Etch), 37% phosphoric acid with benzalkonium chloride (Etch-37), adhesive with chlorhexidine (Peak Universal Bond) and without any agent (PQ1) were investigated by agar-diffusion test. The inhibition-zones were measured after 48 h of incubation. For the tooth-cavity model test; cylindrical cavities were prepared on occlusal dentin surfaces of human molars and divided into four groups (n = 10 cavity/group). Group 1: Ultra-Etch + Peak Universal Bond, Group 2: Ultra-Etch + PQ1, Group 3: Etch-37 + PQ1 were applied. The fourth group without any agent application served as control. The teeth were immersed in 5.8 × 10⁶ cfu/ml of S. mutans solution to infect the cavities for 72 h before the application of the groups. After 72 h, dentin chips were collected from the cavity walls with burs for bacterial counting. Statistical analysis was performed by ANOVA, Bonferroni and Dunnett C tests (p < 0.05). Ultra-Etch and Etch-37 performed similar antibacterial activities in agar-diffusion test. Both acids showed better antibacterial activity compared to adhesives (p < 0.05). The antibacterial activity of PQ1 and Peak Universal Bond was observed to be inactivated by light-polymerization. According to the tooth-cavity model; Group I, II, and III demonstrated reduction in bacterial number and there was no significant difference between them. Antibacterial component additions in etchant and adhesive did not show superior antibacterial activity against S. mutans in both in vitro tests.     

Evaluation of antibacterial effects of contemporary orthodontic bonding materials

Aim: The aim of this study was to evaluate the antibacterial effects of five orthodontic bonding materials commonly used in orthodontics. Materials and Methods: The antibacterial effects of five orthodontic bonding materials were evaluated against Streptococcus mutans and Streptococcus salivarius by direct contact test (DCT). Using the DCT technique, quintet specimens of Transbond XT, Blugloo, Grengloo, Light Bond, and Opal Bond were applied to the bottom and the walls of the five wells of a 96-microtiter plate with a height of 2 mm. Samples were prepared in two sets: 1-day samples and 7-day samples. Ten microliters of bacterial suspension were added to each well for direct contact with each material for 1h at 37 °C. Bacterial growth was then measured in a microplate spectrophotometer hourly at 600 nm for 24 h. Five uncoated wells with identical inoculum sizes served as positive controls. The data obtained at the end of 24 h was statistically analyzed with one-way ANOVA, and post hoc comparisons were done using Tamhane’s T2 test. Results: Blugloo generally showed better antibacterial activity than the other materials. Transbond XT did not show any antibacterial activity. There was a statistically significant difference between Transbond XT and Light Bond in the 1-day sample against S. mutans (p < 0.05). No statistically significant differences were found among the other groups (p > 0.05). Conclusion: Blugloo had the most potent antibacterial activity against S. salivarious.     

Impact of Ozonated Water on the Quality and Shelf-life of Fresh Citrus Fruit,Stone Fruit,and Table Grapes

Spores of fungi that cause postharvest decay of fresh fruit die rapidly in ozonated water. We determined the impact of sporocidal or higher O₃ doses on fruit shelf-life and quality. Green mold and sour rot on citrus fruit, caused by Penicillium digitatum and Geotrichum citri-aurantii, respectively, were not reduced by 20 min immersion in 10 ppm O₃. These fungi infect through wounds; their spores were placed in shallow wounds (l mm wide by 2 mm deep) 24 hr before treatment. On five peach varieties, the average natural incidence of brown rot, caused by Monilinia fructicola, was reduced from 10.9 to 5.4% by 1 min immersion in 1.5 ppm O₃. A treatment of 15 min with 5 ppm O₃ further reduced decay to 1.7%, but consistent control of brown rot was associated only with this severe treatment and it caused shallow pits on the fruit. Brown rot caused by spores placed in wounds before treatment was not controlled. Immersion for 1 or 5 min in 5 ppm O₃ reduced natural aerobic bacteria populations by 1.1 and 1.6 log₁₀ units, respectively, and yeast and filamentous fungal populations by 0.7 and 1.3 log₁₀ units, respectively. Spores of Botrytis cinerea, cause of gray mold, were sprayed on table grape clusters, the clusters were dried, and then immersed for 1 to 6 min in 10 ppm O₃. In two tests, immersion for 1 min in O₃ reduced gray mold from 35% among untreated grapes to about 10%, while in two other tests the incidence was only reduced from 35 to 26%. Minor injury to the rachis of grape clusters occurred at high O₃ rates. Immersion in ozonated water did not control postharvest decay of citrus fruit, injured peaches and nectarines at doses that reliably controlled decay, and on table grapes control was irregular and caused minor rachis injury at high rates.     

The Efficacy of Chlorinated Water Treatments in Minimizing Yeast and Mold Growth in Fresh and Semi-dried Tomatoes

Abstract

A key problem with dried tomatoes for the industries is that the products tend to have limited shelf-life due to yeast and mold growth. This study was undertaken to evaluate the efficacy of chlorine treatments on minimizing yeast and mold populations on fresh and semi-dried tomatoes. Tomatoes were inoculated with molds (4.2 log CFU/g) from contaminated pack of semi-dried tomatoes. These inoculated tomatoes were then treated by washing with water (control) and concentrations of 50, 100, and 200 ppm of chlorinated water for specific length of time (1, 5, and 10 min), and finally analyzed for yeast and mold populations. In this study, the results showed that the maximum log reduction of yeast and mold cells on tomato surface was found to be chlorinated water with a concentration of 200 ppm. At this concentration, washing for 5 and 10 min resulted in 1.7 log reduction and 3.1 log reduction in yeast and mold growth respectively. This was significant (P<0.01) as compared with washing with tap water (control). Drying at 60°C further reduce the microbial load of these pre-treated tomatoes. Results showed that there were reductions in three of the twelve runs while seven of the runs demonstrated an increase in microbial load. This finding is important as it demonstrated that when using a typical drying temperature of 60°C, if the initial microbial load is high, there is a risk that the dehydrator can act as an incubator for more microbial growth. This finding also demonstrated the importance of pretreatment to reduce the initial microbial load before drying commences.     

Effect of Different Concentrations of Ozone on in Vitro Plant Pathogens Development,Tomato Yield and Quality,Photosynthetic Activity and Enzymatic Activities

ABSTRACT

As an effective alternative to traditional pesticides, ozonated water has been used for direct immersion and spraying applications, respectively, against the pathogenic bacterium Ralstonia solanacearum (R. solanacearum) and fungus Alternaria solani (A. solani) that are pathogens of tomato. Immersing R. solanacearum in 0.8 mg/L ozonated water resulted in complete inactivation, while the growth-inhibition rates of the A. solani radial mycelia gradually increased with a 67.0% decrease compared to those of the control at an ozonated water concentration of 7.5 mg/L. This indicated that ozonated water was effective at restraining pathogens in the tomato plant. In addition, spraying wild tomato species (Solanum lycopersicum) plants with ozonated water at concentrations below 10 mg/L for 25 d had no negative effects after treatment compared to those of the control. Photosynthetic activities and the antioxidant system response in the untreated and ozonated water-treated plant leaves had no observable changes. To determine the optimal ozonated water concentration for the pathogen and its host plant, we examined a variety of modes of action, and then, below 10 mg/L of ozonated water. Thus, ozonated water not only inhibits the proliferation of plant pathogens, but is an effective alternative to the pesticides traditionally used to prevent disease in agricultural production.     

The Effect of Ozone on Aflatoxin M1, Oxidative Stability,Carotenoid Content and the Microbial Count of Milk

In the current investigation, attempts were made to determine if ozone treatment can affect the aflatoxin M₁ (AFM₁) content of milk. Aflatoxin M₁ by a pre-determined concentration of 0.56 μg/Kg was added to milk. Milk samples, were then exposed to gaseous ozone (80 mg/min) in containers for durations of 0, 0.5, 1, 2, 5 and 10 min. The longer exposure time to ozone was more efficient in breaking down the AFM₁ in milk. Results indicated that AFM₁ was reduced by 50%, when milk was ozonated at for 5 min. The pH and oxidation value of milk did not change significanty as a result of the treatments. The β-carotene content was significantly reduced and the total microbial count in milk decreased parallel to the longer exposure time. Also, it was through this longer exposure time by ozone that the L* values of milk increased significantly (p < 0.05), while the b* values significantly decreased. To the best of our knowledge, this is the first study that uses ozone to degrade AFM₁ in milk.     

Synthesis of PEO-based di-block glycopolymers at various pendant spacer lengths of glucose moiety and their in-vitro biocompatibility with MC3T3 osteoblast cells

Di-block copolymers of poly(ethylene oxide) (PEO) and glycopolymers at three different pendant spacer lengths of glucose moiety were synthesized by deacetylation of pendant moieties of 2,3,4,6-tetra-O-acetyl-d-glucopyranosides which were prepared by reversible addition-fragmentation chain-transfer (RAFT) process. The water soluble deacetylated copolymers, PEO-b-poly(acryl-d-glucopyranoside) (PEO-b-PAG, 2a), PEO-b-poly[4′-(acryloxy)butyl-d-glucopyranoside] (PEO-b-PABG, 2b), and PEO-b-poly[6′-(acryloxy)hexyl-d-glucopyranoside] (PEO-b-PAHG, 2c) were characterized in comparison with acetylated copolymers by spectroscopic and gel permeation chromatography methods. In order to assess the biocompatibility of these three di-block copolymers, the adhesion (%), viability (%), and proliferation assays were carried out in MC3T3 cells in-vitro at different concentrations from 10 nM to 1000 μM. Qualitative analysis of cell cytoskeletal organization was obtained by immunostaining with talin and integrin α5. It was clearly indicative of well spreading of cells in the presence of all glycopolymers at lower concentrations but with an increase in the concentration (10 and 100 μM) showed significant change in the cell surface morphologies, despite having good cell adhesion and viability as compared to the control conditions. The use of di-block glycolpolymers at?≤?100 μM of the concentration showed very good osteoblast cells adhesion and viability response; however at higher concentrations (1000 μM) of glycopolymers > 80% of cells lost their viability.     

Use of Ozonated Water for Disinfecting Gastrointestinal Endoscopes

The reprocessing of endoscopes is a complex procedure due to their structural design. In the constant search for new antimicrobial substances, recent studies with ozone have yielded great benefits. The present study evaluated the effects of ozonated water used to disinfect endoscopes comparing its efficacy with the conventional technique (2% glutaraldehyde). According to the results obtained, when ozonated water was used (330 mg.min.L^?1), induced a 2 log reduction of the viable microorganisms under the conditions tested. Ozonated water was a potent gastrointestinal endoscopic sanitizer, suggesting it is a feasible alternative for disinfection.     

The effects of self-etch bio-active dental adhesive systems on bacterial microleakage

The aim of this in vitro study was to evaluate the effects of bio-active and non-bio-active self-etch adhesive sytems on bacterial microleakage of class II box cavities with restoration margins in dentin. Two bio-active (Clearfil Protect Bond and F1 Bond II) and two nonbio-active (Clearfil SE Bond and Clearfil s3 Bond) adhesive systems were selected for the study. Eighty mesial and distal class II box cavities were prepared on fourty sound human third molar teeth. The teeth were then divided into four groups with 10 teeth in each group. Groups were restorated using different adhesive systems. The restored specimens were immersed into a culture medium containing streptococcus mutans for bacterial microleakage test. Serial sections of the specimens were used to evaluate the bacterial lekage by using light microscope. The data obtained from the test of bacterial microleakage was evaluated using 2-way mixed analysis of variance (p < 0.05). Statistical analysis showed significant differences between the groups (p < 0.05). Nevertheless it was observed that none of the tested adhesive systems including the bio-active ones were successfull in eliminating bacterial microleakage.     

Research Note: Inactivation Efficiency of Ozonated Water for Fusarium oxysporum Conidia Under Hydroponic Greenhouse Conditions

Ozonated water was used for inactivation of Fusarium oxysporum conidia in sterilized water and inorganic soil-less nutrient medium at different treatment temperatures. F. oxysporum conidia were effectively inactivated in both water and nutrient media and the inactivation curves were almost same at 15°C, 25°C and 30°C. Approximate 4-log orders of F. oxysporum conidia were killed when the ozonated water with initial ozone concentration of 1.0 ppm had been used. The surviving curves, however, were characterized by a tailing-off effect, and the effect was related to the residual ozone concentration in the ozone treated suspensions.     

Ozone Disinfection Efficiency for Indicator Microorganisms at Different pH Values and Temperatures

Disinfection efficiency of ozone was determined in various types of water at different pH (6, 7 and 8) values and temperatures (15, 25 and 35 ^°C) for E. coli and Salmonella. Three different applied ozone concentrations (1.5, 1.7, and 2 mg/L) in the gas phase were applied, and samples were taken at different time intervals to determine microbial survival using spread plate count (SPC) and ozone residual. Highest microbial inactivation was observed in distilled water with applied ozone concentration of 2 mg/L in the gas phase. Survival of E. coli was higher at pH 8 and 15 ^°C as compared to lower pH values and temperatures as depicted by the inactivation kinetics of the test microbes used in the study. Salmonella showed 5 and 6 log removal after contact time of 45 and 60 sec, respectively, at 2 mg/L. Disinfection of mixed culture showed relatively more survival of E. coli; as 3 and 4 log removal of E. coli and 4 and 5 log removal of Salmonella was observed after 45 and 60 sec.