• Journal of Veterinary Clinics
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• v.31 no.3
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• pp.194-198
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• 2014

Methicillin-resistant staphylococci (MRS) are emerging as important pathogens in humans and animals worldwide. The aim of this study was to investigate the prevalence of MRS in the racehorse population and in horse-related personnel in Korea. A total of 195 horses and 18 humans (eight veterinarians, three veterinary hospital staff, and seven horse-handlers) from racehorse farms in Korea were included in the study. The samples were collected from nasal cavities using bacterial transport medium and were cultivated on tryptic soy agar with 5% sheep blood for 3 days at $37^{\circ}C$ to confirm the presence of Staphylococcus spp. Presumptive Staphylococcus spp. isolates were identified by 16S ribosomal RNA gene analysis. The coagulase test and oxacillin susceptibility tests were performed using the tube dilution and disk diffusion methods, respectively. The presence of the mecA gene was determined using a polymerase chain reaction assay. Of the 195 horses, 29 (15.6%) yielded 29 MRS isolates. Twelve (66.7%) of the 18 horse-related personnel yielded 12 MRS isolates. All of the MRS isolates from horses or horse-related personnel were identified as methicillin-resistant coagulase-negative staphylococci (MRCNS). The result of this study suggest that the prevalence of MRS increased with the duration of antibiotic use (p = 0.002). This study also provides evidence for the zoonotic transmission of MRCNS between horses and humans, although further investigations are needed.

• Journal of Life Science
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• v.26 no.4
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• pp.446-452
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• 2016

Garlic (Allium sativum L.) and its extracts have been used in a wide range of applications, including as folk medicines in many Asian countries. This traditional herb has several functional properties and strong biological activities, making it useful as a functional food material. This study investigated the biological activities of solid-garlic after fermentation by lactic acid bacteria. Several solid-garlic fermentation strains of lactic acid bacteria were isolated from Korean traditional fermented food or obtained from the Korean Collection for Type Cultures. Lactic acid bacteria showed selective growth in garlic extracts on MRS media. Fermentation of solid garlic (heated 121℃, 15 min or not heated) by lactic acid bacteria gave total polyphenol and flavonoid contents of 731.0-845.2 g/g and 92.68-413.58 g/g, respectively. The DPPH scavenging activities and SOD like activities were measured as 7,584% and 9499%, respectively. These activities were relatively higher than a positive control, vitamin C. Measurement of antidiabetic activity using α-glucosidase inhibition assay showed that solid garlic fermented with lactic acid bacteria gave a higher activity than the control, acarbose. Fermentation of solid garlic with lactic acid bacteria may therefore help to alleviate adverse biological activities, as well as provide functional food materials.

• Journal of the Korean GEO-environmental Society
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• v.5 no.4
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• pp.13-24
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• 2004

This study was carried out to plan the prevention of the generation and discharge of Acid Rock Drainage (ARD). The Acid Base Accounting(ABA) test was performed for geological materials such as pit wall, waste rock and stream sediments near the Imgi abandoned pyrophyllite mine in Busan, Korea. In addition, hydraulic characteristics were tested with the disk tension infiltrometer around the waste rock dump. Maximum Potential Acidity(MPA) of geological materials near the Imgi mine was 246.942kg $H_2SO_4/t$, and maximum Acid Neutralising Capacity(ANC) was 8.7kg $H_2SO_4/t$. These results indicate the pit wall and waste rock, except most of stream sediments are acid generating geological materials. These have salt and free hydrogen ion which resulted from oxidation of sulfides. Hence they could be convert rain water to acid rock drainage. Although the waste rock dump of the Imgi mine have very low infiltration rate, slopes of the waste rock dump have many "V" type erosion gullies and multi-layers. These gullies and multi-layers have coarse clastic particle layers which have very large hydraulic conductivity. Through this coarse clastic particle layer a large part of rain flow into ground. And also this layer could function as aeration path which induced oxidation of sulfide minerals and generation of ARD continuously.

• Food Science and Preservation
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• v.23 no.3
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• pp.432-437
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• 2016

The objective of this research was to investigate the antioxidant and antimicrobial activities of Jeok Hasuo (Polygonum multiflorum Thunb., PM) and Baek Hasuo (Cynanchi wilfordii Radix, CW) root extracts. Total phenolic contents of PM and CW root extracts were determined and the antioxidant activities of the root extracts were determined by scavenging activity of diphenylpicrylhydrazyl (DPPH) radicals. The antimicrobial activities against Staphylococcus aureus and Propionibacterium acnes were determined and expressed as the minimum inhibitory concentration (MIC). The disc diffusion method was also used to determine the zone of inhibition. The butanol extracts of PM and CW roots exhibited greater total phenolic contents (1,212.6 and 1,454.5 mg/g GAE, respectively) than those of ethanol and water extracts. The ethanol (89.0%) and butanol extracts (88.9%) of PM exhibited significantly greater DPPH radical scavenging activities than that of water extracts (73.1%) (p<0.05). Only ethanol extract exhibited an MIC of 0.8 mg/mL against both bacteria. Zones of inhibition started to form when the concentration of extract was greater than 5 mg/disc. The diameters of the zone of inhibition of PM and CW were measured to be 8.9 and 9.2 mm against S. aureus and P. acnes, respectively, exhibiting the greatest antimicrobial activities among the extracts. This research demonstrated that the PM and CW root extracts possessed not only antioxidant activity but also strong antimicrobial activity against skin-related bacteria.

• Journal of Life Science
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• v.27 no.6
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• pp.611-616
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• 2017

The antibacterial activities of nine oriental herbal medicine extracts were measured against seven kinds of bacteria known to cause food poisoning and disease. The extracts were prepared with distilled water using an autoclave ($121^{\circ}C$ for 30 min). The extraction yields of nine oriental herbal medicines were in the rage of 0.5%-33.4%. The antibacterial activities were evaluated using the paper-disc method. Extracts of Hwangryeon, Jiyu, and Ohbaeja showed antibacterial activities while the others did not. Extracts of Coptis japonica, Hwangryeon, and Sanguisorba officinalis, Jiyu showed antibacterial activities only against Clostridium perfringens and Listeria monocytogenes. Extracts of Rhus javanica, Ohbaeja showed the strongest antibacterial activities against all the bacteria tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of R. javanica extracts were in the range of 2.4~20 mg/ml for the bacteria tested. In conclusion, the extract of R. javanica showed superior antibacterial activities against the seven bacterial strains tested. The MIC and MBC values for each bacterium were represented as strain names (MIC, MBC), which were Bacillus cereus (11.2, 20), Clostridium perfringens (2.4, 4.7), Escherichia coli (9.1, 9.1), Listeria monocytogenes (11.1, 20), Salmonella typhi (4.7, 9.1), Staphylococcus aureus (2.4, 4.7), and Vibrio parahaemolyticus (2.4, 5.3). Further purification and study of this antibacterial material would be helpful for developing antibiotics or promoting synergistic effects with known antibiotics, producing antibacterial material for lengthening the shelf-life of food, and so on.

• Korean Journal of Microbiology
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• v.45 no.2
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• pp.163-169
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• 2009

This study was performed to investigate the type of extended-spectrum $\beta$-lactamases (ESBL) produced by bacteria isolated from the sewage of wastewater treatment plant at Minragdong, Suyong-gu in Busan. The facility is located at sushi restaurants and guides its drain water to the wastewater treatment plant at Yonghodong, Nam-gu in Busan. Samples were collected on January, 2009. A total of 19 strains were selected as potential ESBL positive strains through a double disk synergy test. On the basis of the results from biochemical tests including indole, methyl-red, Voges-Proskauer, Simmon's citrate, decarboxylase-dihydrolase and sugar-fermentation tests, the 19 strains were identified with 16 strains of Escherichia coli and 3 strains of Klebsiella pneumoniae. Out of 19 strains, 4 transconjugants against Escherichia coli J53, which is sodium azide resistant recipient strain, were obtained. The plasmids isolated from transconjugants were used for PCR analysis. The type of each extended-spectrum $\beta$-lactamase (ESBL) produced by the strains was determined on the basis of isoelectric focusing analysis and DNA sequencing. The results indicated that the types of ESBL from Klebsiella pneumoniae were SHV-12 (3 strains), and Escherichia coli was SHV-12/TEM-1 (1 strain), respectively.

• Korean Journal of Clinical Laboratory Science
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• v.48 no.2
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• pp.94-101
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• 2016

Acinetobacter species isolates are important opportunistic pathogens and commonly implicated in nosocomial infections. The therapeutic options for treatment of the bacterial infections are limited because the bacteria isolates are usually multidrug resistant (MDR). In the current study, we investigated various carbapenemase genes in 68 Acinetobacter species isolates. Antimicrobial susceptibilities were tested using the disk diffusion method. Screening of carbapenemase genes was performed via multiplex PCR. In addition, PCR and DNA sequencing were used to identify the carbapenemase genes. Repetitive extragenic palindromic-PCR (REP-PCR) was also performed to assess the clonality of isolates. In our study, A. baumannii isolates were highly resistant to all agents tested while all non-A. baumannii isolates were susceptible to all agents tested, with the exception of aztreonam and cefotaxime. All 51 A. baumannii isolates contained the $bla_{OXA-51}$ gene and 37 (72.5%) isolates also harbored the $bla_{OXA-23}$ gene. In addition, 39 MDR A. baumannii isolates were identified in our study and 37 isolates contained the $bla_{OXA-23}$ gene. The 37 MDR strains harboring $bla_{OXA-23}$ showed type I (n=22) or type II (n=15) banding patterns on their REP-PCR profiles. Our results suggest clonal relation and horizontal spreading of MDR A. baumannii isolates containing the $bla_{OXA-23}$ gene at the hospital located in Daejeon. Continuous investigation of antimicrobial resistant determinants and monitoring emergence and dissemination of MDR isolates is required to prevent and control infection and colonization of MDR A. baumannii isolates.

• Korean Journal of Materials Research
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• v.9 no.12
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• pp.1252-1262
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• 1999

The effect of microstructures on the strength-flangeability of Nb bearing hot-rolled high strength steel was investigated in order to improve the strength-flangeability of conventional TS 580MPa grades HSLA steel for the automotive wheel disc. The low temperature coiling method using 3-step controlled cooling pattern after hot rolling was effective to produce the Nb-bearing high strength steel with the polygonal ferrite and bainite duplex microstructures. It was suggested that the suppressed precipitation of grain boundary cementites and the decreased hardness difference between ferrite matrix and bainite cause the excellent stretch-flangeability of ferrite-bainite duplex microstructure steel. Therefore, the formation and propagation of microcracks were suppressed relative to the conventional HSLA steel with ferrite and pearlite microstructure. In addition, the elongation was improved as compared with that of hot-rolled steel sheets using conventional early cooling pattern because the volume fraction of polygonal ferrite was increased.

• Journal of Life Science
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• v.21 no.2
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• pp.257-264
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• 2011

Seventy five methicillin- resistant Staphylococcus aureus (MRSA) strains and 24 methicillin- susceptible S. aureus (MSSA) were isolated from clinical specimens obtained from a hospital in Suncheon, Jeonnam province, Korea, from July to December, 2009. Antibiotic resistance was determined using the disc diffusion method. Genes encoding enterotoxin (SE), toxic shock syndrome toxin-1 (TSST-1), exfoliative toxin (ET) and Panton-Valentine leukocidin (PVL) were detected by multiplex PCR-mediated amplification using specific primers. Sixty (80%) MRSA isolates possessed either one or more toxin genes and the most common pattern that coexisted in MRSA was seb, sec, seg, sei and tst (22.7%) followed by coexistence of sec, seg, sei and tst genes (18.7%). Gene pvl encoding leukocidin was not found. Significant correlation between the production of sec, seg, sei and tst genes was found. MRSAs were resistant to erythromycin (89% of the isolates), gentamicin (70.7%), ciprofloxacin (69.3%), clindamycin (61.3%) and tetracycline (58.7%), while MSSAs were susceptible to the antibiotics with the exception of erythromycin. Toxin genes seb, sec and tst were related to the tetracycline resistance of MRSA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.327-332
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• 2016

This study investigated the antioxidant and antimicrobial activities of various solvents (acetone, ethyl acetate, and ethanol) for extraction of Auricularia auricula-judae. Antioxidant activity was evaluated by determining total polyphenol and flavonoid contents, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity. Total polyphenol and flavonoid contents were not significantly different among the extracts, whereas DPPH radical scavenging activity and ABTS cation radical scavenging activity were significantly higher in ethanol and acetone extracts. DPPH radical scavenging activities of ethanol and acetone extracts showed high values (58.7% and 46.7%, respectively). The antimicrobial properties of these extracts were determined against six bacterial pathogens (Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa, and Enterobacter cloacae) by the disc diffusion method. The acetone extracts showed antimicrobial activities against all tested bacteria, and all extracts showed the highest antimicrobial activity against B. subtilis.