Lee H.-H.,Health and Environment Institute of Gwangju |
Lee H.-H.,Chonnam National University |
Cho J.-Y.,Mokpo National University |
Cho J.-Y.,Chonnam National University |
And 2 more authors.
Horticulture Environment and Biotechnology | Year: 2011
The ethyl acetate (EtOAc) layer of the hot water extracts of Camellia japonica flowers was found to have higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity than the other solvent layers. Nine phenolic compounds were isolated and purified from the EtOAc layer by Sephadex LH-20 column chromatography and octadecyl silane-high performance liquid chromatography using a guided DPPH radical-scavenging assay. The isolated compounds were identified as 3,4,5-trihydroxybenzoic acid (1), 3,4-dihydroxybenzoic acid (2), 4-hydroxybenzoic acid (3), 2,3-digalloyl-O-α-d-glucopyranoside (4), 2,3-digalloyl-O-β-d-glucopyranoside (5), quercetin 3-O-β-d-galactopyranoside (6), quercetin 3-O-β-d-glucopyranoside (7), kaempferol 3-O-β-d-galactopyranoside (8), and kaempferol 3-O-β-d-glucopyranoside (9), based on mass spectrometry and nuclear magnetic resonance. Four compounds (6-9) had been previously identified in the leaves of this plant, but other compounds (1-5) were newly isolated from this plant. Their DPPH radical-scavenging activities based on the 50% scavenging concentration decreased in the following order: 4 = 5 (4.7 μM) > 1 (9.8 μM) > 6 = 7 (8.2 μM) > α-tocopherol (24.7 M) > ascorbic acid (25.1 μM) > 2 (35. 6 M) > 3 = 8 = 9 (> 250 μM). Quercetin glycosides (6, 7), gallic acid (1) and its glucosides (4, 5) showed higher DPPH radical-scavenging activities than other compounds. These results indicate that the antioxidant effect of C. japonica flowers may be attributable to quercetin glycosides and gallic acid derivatives. These isolated compounds will be useful in basic studies of plant physiology, food manufacturing, and biological function of C. japonica flowers. © 2011 Korean Society for Horticultural Science. Source
Profile of antimicrobial resistance of Staphylococcus aureus and molecular epidemiologic characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolated from hands of people using multitude facilities
Kim T.,Health and Environment Institute of Gwangju |
Kim M.J.,Health and Environment Institute of Gwangju |
Kim S.H.,Health and Environment Institute of Gwangju |
Kee H.-Y.,Health and Environment Institute of Gwangju |
And 5 more authors.
Infection and Chemotherapy | Year: 2012
Background: The purpose of this study was to investigate perception of hand hygiene and actual hand washing practices of people who used public facilities as well as the presence of indicator bacteria and food-borne pathogens on their hands. Data from this study will be used as a tool for public education and provide basic information on the potential risk for the spread of infectious disease by hands. Materials and Methods: Sixty S. aureus and 15 methicillin-resistant S. aureus (MRSA) were recovered from 500 swab samples from hands of people in public places, including super markets and amusement facilities in Gwangju Metropolitan City during February to May 2011. Using conventional methods and the Vitek system, all of the isolates were confirmed as Staphylococcus auerus (S. aureus). Antimicrobial susceptibility was determined by performing disk diffusion testing according to the Clinical Laboratory Standard Institute guidelines. The minimum inhibition concentrations (MICs) of MRSA isolates were tested using E-test strips. To confirm the MRSA, polymerase chain reaction (PCR) for the S.aureus-specific gene and mecA gene was performed. Gene detection using PCR, SCCmec typing, Panton-Valentine Leukocidin (PVL), and Multilocus sequence typing (MLST) were performed on all isolates of MRSA. Results: Of 60 S. aureus isolates, 48 (80%) harbored at least one type of enterotoxin gene: two, three, four, and five types of enterotoxin gene were found in 16 (26.7%), seven (11.7%), 10 (16.7%), and eight (13.3%) isolates, respectively. The most prevalent antimicrobial resistance observed in the S. aureus isolates was to penicillin (92%, 55/60), followed by erythromycin (35%, 21/60), oxacillin (32%, 19/60), and ampicillin (23%, 14/60). No resistance was observed against vancomycin, clindamycin, linazolid, rifampin, imipenem, trimethoprim/sulfamethoxazole, and telithromycin. In this study, based on molecular characterization of MRSA isolates, all MRSA, except for one isolate, belonged to ST72 and SCCmec type IV. Eleven of 15 (78.6%) MRSA were ST72:SCCmecIV:t324. Conclusions: In this study, we detected serious pathogens, including S. aureus and MRSA, from swab samples of peoples' hands. Most S. aureus isolates harbored the enterotoxin gene and the types of MRSA isolated in this study were community-associated MRSA, indicating the importance of washing hands for public health. © 2012 by The Korean Society of Infectious Diseases. Korean Society for Chemotherapy. Source
Lee H.-M.,Chonnam National University |
Kwon J.,Korea Basic Science Institute |
Choi J.-S.,Korea Basic Science Institute |
Lee K.-H.,Chonnam National University |
And 5 more authors.
Journal of Food Protection | Year: 2013
Current molecular methods that include PCR have been used to detect norovirus in many food samples. However, the protocols require removing PCR inhibitors and incorporate time-consuming concentration steps to separate virus from analyte for rapid and sensitive detection of norovirus. We developed an immunomagnetic separation (IMS) and a quantum dots (QDs) assay to detect norovirus eluted from fresh lettuce with Tris buffer containing 1% beef extract (pH 9.5). IMS facilitated viral precipitation with a 10-min incubation, whereas virus concentration using polyethylene glycol (PEG) requires more than 3 h and an additional high-speed centrifugation step to precipitate virus before reverse transcription PCR (RT-PCR) analysis. The fluorescence intensity of QDs was detected qualitatively on norovirus dilutions of 1021 to 1023 in a stool suspension (100 RTPCR units/ml). The results suggest that a fluorescence assay based on IMS and QDs is valid for detecting norovirus qualitatively according to fluorescent signal intensity within the same virus detection limit produced by IMS-RT-PCR and PEG-RT-PCR. © International Association for Food Protection. Source
Park S.H.,Chonnam National University |
Park S.H.,Gwangju University |
Kim Y.O.,Chonnam National University |
Kim Y.O.,Gwangju University |
And 10 more authors.
Brain and Development | Year: 2015
Background and purpose: Rotavirus was the most common virus in benign convulsions with mild gastroenteritis (CwG), with an incidence of 40-50%. As rotavirus gastroenteritis has decreased since introduction of rotavirus vaccine, we investigated the incidence of CwG and rotavirus positivity after introduction of the vaccine. Methods: We retrospectively reviewed the medical records of 987 patients aged between 3. months and 3. years who were admitted to the Chonnam National University Hospital between March 2005 and February 2014 due to their first seizures and enrolled 102 patients with CwG. The incidences of CwG among seizure patients and stool rotavirus positivity in CwG patients were compared between two periods: period I (March 2005-February 2010) and period II (March 2010-February 2014). Other viruses in stools were also reviewed. Results: The incidence of CwG were 8.47% (45 among 531 patients) in period I and 12.50% (57 among 456 patients) in period II (P= 0.018). Stool rotavirus was checked in 85.29% (87 patients): 82.22% (37 patients) in period I and 87.72% (50 patients) in period II (P= 0.166). The positivity of rotavirus was 40.54% (15 patients) in period I and 16.00% (8 patients) in period II (P= 0.01.). In the patients without rotavirus gastroenteritis, 30 patients were test for other viruses. Norovirus was the most common (56.67%, 17 patients) and was more frequent in period II than I (71.43% versus 22.22%, P= 0.018). Conclusion: After introduction of rotavirus vaccine, rotavirus-associated CwG has decreased but the incidence of CwG has increased due to an increase of norovirus. © 2014 The Japanese Society of Child Neurology. Source
Kim T.S.,Health and Environment Institute of Gwangju |
Km M.J.,Health and Environment Institute of Gwangju |
Kang Y.M.,Health and Environment Institute of Gwangju |
Oh G.,Health and Environment Institute of Gwangju |
And 8 more authors.
Korean Journal of Food Science and Technology | Year: 2014
Toxin-producing Bacillus cereus is the causative agent of two different types of food poisoning: the emetic and the diarrheal types. This study was conducted to investigate the presence of enterotoxin and emetic toxin genes in 263 B. cereus isolated from 619 different ready-to-eat food items. Hemolytic enterotoxins hblA, hblC, and hblD were detected in 85.6, 41.1, and 76.8%, respectively, of the B. cereus isolates. About 67.0% (175/263) of the isolates presented all of three genes. Non-hemolytic enterotoxins nheA, nheB, and nheC were detected in 100, 97.0, and 68.4% of the isolates, respectively. Approximately 90.0% (236/263) of the isolates presented all of these three non-hemolytic enterotoxin genes. Emetic toxin gene, CER, was detected in 132 of 263 (50.2%) isolates. Computer-assisted cluster analysis of Rep-PCR profiles showed a high genetic diversity among the isolates. All B. cereus isolates from food samples tested in this study carried at least 6 of 10 toxin genes. © The Korean Society of Food Science and Technology. Source