• Restorative Dentistry and Endodontics
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• 제34권5호
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• pp.390-396
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• 2009

The aim of this study was to evaluate endodontic irrigation methods with $EndoVac^{(R)}$ and $EndoActivator^{(R)}$ in the elimination of Enterococcus faecalis from the root canals. Extracted 70 human single-rooted teeth were used. The canals were instrumented by a crown-down technique with .04 taper ProFile to ISO size 40. After the teeth were autoclaved, the canals were inoculated with E. faecalis and incubated for 48 h. The teeth were randomly divided into three experimental groups of 20 teeth each according to canal irrigation methods and two control groups as follows: group 1 - $EndoVac^{(R)}$; group 2 - $EndoActivator^{(R)}$; group 3-Conventional needle irrigation method. After canal irrigation using 2.5% NaOCl. first samples (S1) were taken using sterile paper point. And the canals were filled with sterile brain heart infusion (BHI) broth and incubated for 24 h, then second samples (S2) were taken. The samples were cultured on BHI agar plate to determine the numbers of colony forming units (CFU). In first sampling (S1), only one canal of conventional method among the all experimental groups was positive cultured. In second sampling (S2), $EndoVac^{(R)}$ group showed the least positive culture numbers of E. faecalis. There was statistically significant difference between the $EndoVac^{(R)}$ and conventional needle irrigation methods in the mean value of Log CFU. According to the results of this study, $EndoVac^{(R)}$ showed better efficacy than conventional needle irrigation method in the elimination of E. faecalis from the root canal.

• Journal of Photoscience
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• 제11권2호
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• pp.55-59
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• 2004

The present investigation is an attempt to create an optimized protocol for a bactericidal modality of different powers of He-Ne laser radiation to eliminate periodontitis disease causing bacteria from dental plaques. Periodontitis is most prevalent infectious disease of men and caused by a limited number of Gram negative oral bacteria. Porphyromonas gingivalis and Streptococcus sanguis are the important bacteria responsible for periodontitis diseases. Effect on periodontitis disease causing bacteria were produced by the exposure of different powers of He-Ne laser light i.e. 9 mW, 17 mW and 26 mW of red colour of wavelength 632.8 nm in two different periods of time i.e. 10 min. and 20 min. in the presence of dye Methylene blue (MB) used as a photosensitizer. The results have been shown in terms of percentage inhibition of colony forming units (cfu.) of bacteria. This study has shown that maximum inhibition of cfu. were observed in Laser+MB-20 min. exposure time. This inhibition was followed by Laser+MB-10 min., but minimum inhibition was seen in Laser only at 10 min. exposure. In case of effect of methylene alone on the cfu. of bacteria, it was seen that MB have not shown more inhibition of cfu. and it had shown that the no. of cfu. are very similar to that of control. The above observation of the present study was seen in case of every 3 different type of used powers of laser for both the bacteria. Maximum percentage inhibition of cfu. were seen in case of 26mW powers of He-Ne laser, which was 67. 28% to 61.42% for Porphyromonas gingivalis and Streptococcus sanguis respectively. So, increasing the power of laser (safe range for dentistry is 3-30 mW) under conditions shows an increased percentage inhibition of cfu. Thus the present investigation may be a useful adjunct with mechanical debridement in the prevention of recolonization of subgingival lesions by pathogenic microorganisms which are harmful and drug resistant.

• Journal of Food Hygiene and Safety
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• 제26권4호
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• pp.361-365
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• 2011

To evaluate the indoor air quality of food manufacturing plants, the presence of viable bacteria and fungi was assessed in the indoor air of the facilities at which 9 food items were manufactured. Air samples were collected from the general zone, low clean zone and clean zone of each factory with an air sampler, in combination with plate counts agar using for bacteria, and dichloran-glycerol agar for fungi. The samples were incubated at $25^{\circ}C$ for 4 to 7 days. After culture, the colony forming units (CFU) on each plate were counted and corrected with a positive hole conversion table. The average concentration of bacteria was $2.2{\times}10^3\;CFU/m^3$ in the general zone, $1.2{\times}10^3\;CFU/m^3$ in the low clean zone and $7.3{\times}10^2\;CFU/m^3$ in the clean zone. The average concentration of fungal microbes was $2.5{\times}10^3\;CFU/m^3$ in the general zone, $2.6{\times}10^3\;CFU/m^3$ in the low clean zone, and $2.0{\times}10^2\;CFU/m^3$ in the clean zone. No meaningful differences were detected between the general zone and the low clean zone, but the clean zone had significantly lower concentrations than the other zones. Additionally, the identification of the fungi was performed according to morphological method using a giant culture and slide culture. The fungi were identified as belonging to 18 genera, and the genera Cladosporium(33%), Penicillium(29%) and Aspergillus(26%), predominated. Aspergillus isolates were identified to species level, and A. ochraceus, a mycotoxigenic species, was identified. As part of the effort to control the quality of the indoor air of food manufacturing plants, our results show that continued studies are clearly warranted.

• Journal of the Korean Dietetic Association
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• 제25권1호
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• pp.1-16
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• 2019

This study examined the microbiological quality of daycare center meals. Six menu items from five daycare centers in Daegu included uncooked processed foods (seasoned cucumber and lettuce salad), post-preparation after cooking processed foods (rolled omelet and seasoned soybean sprout), and cooking processed foods (panbroiled beef with oyster sauce and seasoned pork roast). Microbiological analyses were performed for the aerobic plate counts (APC), coliforms, and Escherichia coli. The analyses were conducted in July and November 2017. The mean APC and coliform count of seasoned cucumber decreased significantly from 4.71 log colony forming units (CFU)/g and 2.50 log CFU/g in July to 4.07 log CFU/g and 1.78 log CFU/g in November, respectively (P<0.01 and P<0.001). The APC of panbroiled beef with oyster sauce and seasoned pork roast were significantly lower in July (1.84 and 1.79 log CFU/g) than in November (2.41 and 2.28 log CFU/g) (P<0.001). The coliform counts of panbroiled beef with oyster sauce and seasoned pork roast were significantly greater in November (2.11 and 1.62 log CFU/g) (P<0.001). E. coli was not detected. Among the foods prepared using the three preparation processes, the post-preparation after cooking processed foods had the lowest microbial quality. The APC and coliform counts of cooking processed foods were satisfactory in July, with an acceptable rating for pan-broiled beef with oyster sauce in November. Time-temperature control and the prevention of cross-contamination are essential during meal production for food safety, regardless of the season.

• Journal of Korean Biological Nursing Science
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• 제23권4호
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• pp.339-346
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• 2021

Purpose: To determine the extent of environmental contamination and the effect of disinfection around patients with carbapenem-resistant Enterobacteriaceae (CRE) using adenosine triphosphate (ATP) measurements and microbial culture tests. Methods: The subjects of this study were 10 patients hospitalized in a single room due to CRE from April 13 to 21, 2021. One hundred and sixty samples were collected using cotton swabs from the patients' environment including the surface and drain of sinks and toilet seats before and after disinfection of the room after discharge. Twenty-one samples were collected from the nurses' personal digital assistants (PDAs), keyboards, and computer mice before disinfection. The relative light units (RLUs) and CRE colony-forming units (CFU) of 181 samples were measured using ATP test equipment and chrome agar plates, respectively. Results: The highest RLUs were measured at the sink drains before and after disinfection. Four CRE samples from the sink drains (2), sink surface (1), and toilet bowl (1) before disinfection were cultured. Based on the failure criteria (≥ 250 RLU/cm² and ≥ 1 CFU/100 cm²), 90 % and 50 % of the samples from the drain exceeded the failure criteria before and after disinfection, respectively. In the culture tests, CRE was not detected after disinfection. Conclusion: According to the RLU and CFU measurements of drain samples, disinfection was not effective. Thus, improvements in the disinfection methods of drains, as well as more efficient and systematic environmental decontamination and disinfection evaluation tools, are needed to accurately evaluate the effectiveness of disinfection in various places.

• Journal of Environmental Health Sciences
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• 제33권5호
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• pp.422-427
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• 2007

The purposes of this study were to investigate the concentration of total coliforms in sewage effluents during the period from August 2004 to October 2005. The removal efficiency range of multi-tube method and plate count method were $31.3{\sim}99.5%$ and $66.8{\sim}99.2%$, respectively. Though a correlation between the multi-tube method and the plate count method in the same sample is low, not only is an experimental procedure very simple, but the time required also is short. The seasonal correlation between methods showed more sensitive spring and summer than autumn and winter. So the study indicated plate count method can be used in rapid and reliance identification of total coliform more than the multi-tube method.

• Journal of Plant Biotechnology
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• 제44권2호
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• pp.156-163
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• 2017

A greenhouse experiment was conducted for evaluation of ecological effects of transgenic melon plants in the rhizospheric soil in terms of soil properties, enzyme activities and microbial communities. Organic matter content of soil under transgenic melon plants was significantly higher than that of soil with non-transgenic melon plants. Significant variations were observed in organic matter, total P and K in soil cultivation with transgenic melon plants. There were also significant variations in the total numbers of colony forming units of fungi, actinomycetes and bacteria between soils treated with transgenic and non-transgenic melon plants. Transgenic and non-transgenic melon significantly enhanced several enzymes activities including urease, acid phosphatase, alkalin phosphatase, arysulphtase, ${\beta}$ glucosidase, dehydrogenase, protease and catalase. Soil polyphenoloxidase activity of $T_1$ transgenic melon was lower than that of $T_0$ transgenic melon and a non-melon plant during the same period. The first generation transgenic melon plants ($T_0$) showed significantly greater (p<0.05) effect on the activitiy of arylsulfatase, which increased from $2.540{\times}10^6CFU\;g^{-1}$ (control) to $19.860{\times}10^6CFU\;g^{-1}$ ($T_0$). These results clearly indicated that transgenic melon might change microbial communities, enzyme activities and soil chemical properties.

• Journal of Oral Medicine and Pain
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• 제21권1호
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• pp.123-131
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• 1996

Bacteremia occurs in a wide variety of clinical procedures in oral cavity. Reduction of the number of causative microorganisms of infective endocarditis in oral cavity by local administration of antimicrobial agents decreases the magnitude of bacteremia and possibility of infective endocarditis. The effects of chlorhexidine on Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, Streptococcus gordonii, Staphylococcus aureus, and Staphylococcus epidermis were investigated by measurement of turbidity. The effects of 0.1% chlorhexidine gargling for 7 days on oral bacterial flora, total streptococci, S. mutans, S. aureus, and S. epidermis in whole saliv a of 7 healthy human subjects, were investigated by measurement of Colony Forming Units (CFU). The obtained results were as follows : 1. Chlorhexidine showed significant antimicrobial effects on Streptococcus snaguis, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, Streptococcus gordonii, Staphylococcus aureus, and Staphylococcus epidermis. However, the effects on S. sanguis and S. gordonii were not apparent compared with other microorganisms. 2. Oral gargling of 0.1% chlorhexidine decreased the CFU values of normal oral bacterial flora, total streptococci, S. mutans, S. aureus, and S. epidermis in whole saliva. The antimicrobial effects were significant after 4 days of chlorhexidine gargling. 3. Local antimicrobial administration in addition to systemic antibiotic prophylaxis can be highly recommended as an effective adjunct regimen for prevention of infective endocarditis.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.503-509
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• 2018

Endive is widely consumed in a fresh-cut form owing to its rich nutritional content. However, fresh-cut vegetables are susceptible to contamination by pathogenic bacteria. This study investigated the antibacterial activities of the combined treatment of cinnamon leaf oil emulsion containing cetylpyridinium chloride or benzalkonium chloride (CLC and CLB, respectively) as a cationic surfactant and ultrasound (US) against Listeria monocytogenes and Escherichia coli O157:H7 on endive. The combined treatment of CLC or CLB with US reduced the population of L. monocytogenes by 1.58 and 1.47 log colony forming units (CFU)/g, respectively, and that of E. coli O157:H7 by 1.60 and 1.46 log CFU/g, respectively, as compared with water washing treatment. The reduction levels of both pathogens were higher than those observed with 0.2 mg/ml sodium hypochlorite. In addition, the combined treatment showed no effect on the quality of the fresh-cut endive (FCE). In particular, the degree of browning in FCE was less for the treatment group than for the control and water washing treatment groups. Thus, cationic surfactant-based cinnamon leaf oil emulsions combined with US may be an effective washing treatment for the microbial safety of FCE.

• Journal of Ginseng Research
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• 제34권4호
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• pp.321-326
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• 2010

Enzymatic treatment conditions for red ginseng residue (RGR) were investigated to apply RGR as a microbial medium. Polysaccharide hydrolyase and protease were screened to obtain high solid and carbohydrate yields, and a good degree of carbohydrate hydrolysis. The optimal dosage and reaction time for Viscozyme, the chosen polysaccharide hydrolyase, were found to be 1.0% (w/w) and 3 h, respectively. Of the tested proteases, Flavourzyme, whose optimal dosage was 0.5% (w/w), was selected. Co-treatment with the optimal dosages of Flavourzyme and Viscozyme increased solid yield, carbohydrate yield, and degree of carbohydrate hydrolysis by 76%, 65%, and 1,865%, respectively, over levels in non-treated RGR. The culture characteristics of Leuconostoc mesenteroides strain KACC 91459P grown in enzymatically hydrolyzed red ginseng residue (ERGR) and RGR suspensions were compared. After cultivation for 6 h, the viable cell counts of both cell suspensions rapidly increased to $1.3{\times}10^9$ colony-forming units (CFU)/g. Moreover, while the viable cell population drastically decreased to $2.4{\times}10^6\;CFU/g$ for cells grown in RGR medium, it was maintained in cells fermented in ERGR medium for 24 h.