• Asian-Australasian Journal of Animal Sciences
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• v.33 no.2
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• pp.203-211
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• 2020

Objective: Staphylococcus aureus (S. aureus) is one of the major microorganisms responsible for subclinical mastitis in dairy cattle. The present study was designed with the aim to explore the DNA methylation patterns using the Fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) techniques in a S. aureus-infected mouse model. Methods: A total of 12 out-bred Institute of Cancer Research female mice ranging from 12 to 13 weeks-old were selected to construct a mastitis model. F-MSAP analysis was carried out to detect fluctuations of DNA methylation between control group and S. aureus mastitis group. Results: Visible changes were observed in white cell counts in milk, percentage of granulocytes, percentage of lymphocytes, CD⁴⁺/CD⁸⁺ ratio (CD⁴⁺/CD⁸⁺), and histopathology of mice pre- and post-challenge with S. aureus. These findings showed the suitability of the S. aureus-infected mouse model. A total of 369 fragments was amplified from udder tissue samples from the two groups (S. aureus-infected mastitis group and control group) using eight pairs of selective primers. Results indicated that the methylation level of mastitis mouse group was higher than that in the control group. In addition, NCK-associated protein 5 (Nckap5) and transposon MTD were identified to be differentially methylated through secondary polymerase chain reaction and sequencing in the mastitis group. These observations might play an important role in the development of S. aureus mastitis. Conclusion: Collectively, our study suggests that the methylation modification in Nckap5 and transposon MTD might be considered as epigenetic markers in resistance to S. aureus-infected mastitis and provided a new insight into S. aureus mastitis research in dairy industry and public health.

• Journal of dental hygiene science
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• v.8 no.3
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• pp.183-187
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• 2008

The objective of this study was to assess the level of contamination of dental equipment surfaces by Staphylococcus aureus and to obtain basic information for the prevention against cross infection between students and outpatients. Human samples were collected by rubbing the oral cavity, anterior noses, and lip of students and outpatients with sterile cotton swabs. Environmental samples were collected from 11 sites at practical laboratory, 4 sites at seminar room, and 5 sites at sterilizing room before, during, and after clinical procedures. These samples were cultured on brain-heart infusion agar at $37^{\circ}C$ for 24 hours. Gram-stained and identified as S. aureus colonies were counted each period and these results were analyzed by t-test and ANOVA test. In human, oral cavity showed the greatest S. aureus counts and there were no statistically significant differences between students and outpatient. Practical laboratory revealed the greatest S. aureus among all environmental groups. The greatest number of S. aureus was observed during clinical procedures (P < 0.05) and light handles, chair head, and spittoon showed a high level of statistically significant differences. In conclusion, S. aureus was dispersed in human and dental clinical environment and increased their number during clinical procedures.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.19-25
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• 2017

Staphylococcus aureus (S. aureus) is a common gram-positive bacterium that causes serious infections in humans and animals. With the continuous emergence of methicillin-resistant S. aureus (MRSA) strains, antibiotics have limited efficacy in treating MRSA infections. Accordingly, novel agents that act on new targets are desperately needed to combat these infections. S. aureus alpha-hemolysin plays an indispensable role in its pathogenicity. In this study, we demonstrate that sclareol, a fragrant chemical compound found in clary sage, can prominently decrease alpha-hemolysin secretion in S. aureus strain USA300 at sub-inhibitory concentrations. Hemolysis assays, western-blotting, and RT-PCR were used to detect the production of alpha-hemolysin in the culture supernatant. When USA300 was co-cultured with A549 epithelial cells, sclareol could protect the A549 cells at a final concentration of $8{\mu}g/ml$. The protective capability of sclareol against the USA300-mediated injury of A549 cells was further shown by cytotoxicity assays and live/dead analysis. In conclusion, sclareol was shown to inhibit the production of S. aureus alpha-hemolysin. Sclareol has potential for development as a new agent to treat S. aureus infections.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.81-86
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• 2002

A bacteriocin producing lactic acid bacteria was isolated from ground beef and the strain was identified as Lactobacillus plantarum ssp. by use of API carbohydrate fermentation pattern and physiological tests. The bacteriocin produced by L. plantarum KU107 exhibited a good spectrum of activity against foodborne pathogens including Bacillus cereus, Escherichia coli, Listeria ivanovii, Listeria monocytogenes, Pseudomonas aeruginosa, Pseudomonas chlororaphis, Staphylococcus aureus, Staphylococcus intermedius, Salmonella typhimurium and Yersinia enterocolitica. The bacteriocin was active over a wide pH range and stable of heat treatment, and inactivated by treatment with proteases. A bacteriocin from L. plantarum KU107 was effetive in reducing S. aureus in tryptic soy broth. On the ground beef containing S. aureus was added with the crude bacteriocin, S. aureus was inhibited during storage period at 4$\^{C}$.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.3
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• pp.155-163
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• 2005

The purpose of this study is to investigate the carrier rate of S. aureus in the community, antibiotic susceptibility patterns of the organism, detection of MRSA and mecA gene in MRSA. Identification and antibiotic resistance patterns of S. aureus and MRSA were done by MicroScan Panels. MRSA strain was confirmed by disk diffusion method using oxacillin disk. The mecA gene in MRSA was detected by PCR. Eighty-four strains (27.4%) of S. aureus were isolated from the nasal specimens of 307 university students in Busan in 2004. Sixty-eight strains (81.9%) of 83 S. aureus were resistant to penicllin, 16 strains(19.3%) to erythromycin, 15 strains (18.1%) to gentamicin, 12 strains (14.5%) to tetracycline, 6 strains (7.2%) to chloramphenicol, 3 strains (3.6%) to ofloxacin, 2 strains (2.4%) to cefepime, clindamycin, imipenem, meropenem, norfloxacin, respectively. One strain (1.2%) was resistant to ciprofloxacin, cefazolin, cefotaxime, cefuroxime, and oxacillin. And all the strains (100%) of 84 S. aureus were susceptible to amoxicilin/K clavulanate, ticarcillin/K clavulanate, trimethoprim/sulfamethoxazole, rifampin, syncroid, teicoplanin, and vancomycin. One strain of 84 S. aureus isolates was methicillin-resistant Staphylococcus aureus (MRSA). The mecA gene was detected from the MRSA strain.

• Journal of Microbiology and Biotechnology
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• v.29 no.8
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• pp.1177-1183
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• 2019

Grapefruit seed extract (GSE) is a safe and effective preservative that is used widely in the food industry. However, there are few studies addressing the anti-biofilm effect of GSE. In this study, the anti-biofilm effect of GSE was investigated against biofilm-forming strains of Staphylococcus aureus and Escherichia coli. The GSE minimum inhibitory concentration (MIC) for S. aureus and E. coli were $25{\mu}g/ml$ and $250{\mu}g/ml$, respectively. To investigate biofilm inhibition and degradation effect, crystal violet assay and stainless steel were used. Biofilm formation rates of four strains (S. aureus 7, S. aureus 8, E. coli ATCC 25922, and E. coli O157:H4 FRIK 125) were 55.8%, 70.2%, 55.4%, and 20.6% at $1/2{\times}MIC$ of GSE, respectively. The degradation effect of GSE on biofilms attached to stainless steel coupons was observed (${\geq}1$ log CFU/coupon) after exposure to concentrations above the MIC for all strains and $1/2{\times}MIC$ for S. aureus 7. In addition, the specific mechanisms of this anti-biofilm effect were investigated by evaluating hydrophobicity, auto-aggregation, exopolysaccharide (EPS) production rate, and motility. Significant changes in EPS production rate and motility were observed in both S. aureus and E. coli in the presence of GSE, while changes in hydrophobicity were observed only in E. coli. No relationship was seen between auto-aggregation and biofilm formation. Therefore, our results suggest that GSE might be used as an anti-biofilm agent that is effective against S. aureus and E. coli.

• Food Science of Animal Resources
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• v.32 no.1
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• pp.91-97
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• 2012

Antimicrobial resistance of foodborne pathogens is an important food safety issue worldwide as well as in Korea. In this study, exposure to antimicrobial resistant (AMR) Stapylococcus aureus was assessed from the consumption of pork based food dishes prepared in food service operations using the Monte Carlo simulation. Thirty five isolates of S. aureus were obtained from 124 semi-processed pork products and their antibiotic resistance patterns were determined. The highest resistance was observed for penicillin (76.7%) followed by ampicillin (70.0%). Two isolates were resistant to oxacillin (6.7%) and no vancomycin resistance was observed. Dietary exposure to penicillin resistant S. aureus as the most frequently observed AMR S. aureus from pork-based dishes was estimated based on contamination data as well as compliance to guidelines for time and temperature controls during food service operations. The mean level of penicillin resistant S. aureus in pork dishes during preparation was below 1 Log CFU/g. As a conservative approach, 95th percentile estimated level of penicillin resistant S. aureus was below the level for toxin production. The estimated probability of staphylococcal intoxication by AMR S. aureus was very low using currently available data.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.372-379
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• 2009

Purpose: The purpose of this study was to compare the effect on antibacterial activities and wound healing effect of silver containing dressings with which of Betadine against Staphylococcus aureus and Pseudomonas aeruginosa. Methods: One full thickness skin defects in rats(n=72) were developed on the back and were given rise to infection with S. aureus(n=36) and P. aeruginosa(n=36). The 72 mice were divided into 6 groups : Acticoat$^{(R)}$, Aquacel$^{(R)}$-Ag, Medifoam silver$^{(R)}$, Polymen silver$^{(R)}$, Ilvadon$^{(R)}$ and Betadine(control group) dressing groups. Five silver containing dressings and Betadine were assesed on infected wound. Measurement of wound size change, bacterial colonies count and histologic findings was applied. Antibacterial activity was analyzed with bacterial restricted zone in Mueller Hinton agar. Results: On S. aureus, wound size was more decreased in all treated groups as compared with betadine, however Ilvadon$^{(R)}$ was less decreased on P. aeruginosa. In histologic findings, experimental group showed more effective findings than others on S. aureus, however on P. aeruginosa, which was showed similar. Acticoat$^{(R)}$ was best effective in wound healing against S. aureus and P. aeruginosa. The bacterial colonies count was increased in all treated groups except Acticoat$^{(R)}$ as compared with the control group on S. aureus, which was decreased in Acticoat$^{(R)}$ and Ilvadon$^{(R)}$ group on P. aeruginosa. There were not statistical differences. The restricted zone was shown in Mueller - Hinton agar of all groups except Medifoam silver$^{(R)}$ group on S. aureus, which was shown of all groups on P. aeruginosa. There were statistical differences. Conclusion: This study suggests that silver containing dressings may have not better potential than Betadine in assisting management of wounds at risk of infection on S. aureus and P. aeruginosa. However, which have better antibacterial activity on S. aureus and P. aeruginosa.

• Journal of Life Science
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• v.18 no.1
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• pp.69-74
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• 2008

This study carried out to investigate the antimicrobial resistance and biochemical characteristics of Staphylococcus aureus (S. aureus) isolated from reproductive and respiratory tract in Thoroughbred horse. The specimens were collected from equine vaginal mucosa and upper respiratory tract from March to December 2006 using a culture swab in Korea. S. aureus suspected colonies on blood agar plates were selected and identified as standard biochemical tests and PCR (Applied Biosystems, USA). Antimicrobial resistance test of S. aureus isolates was performed with 30 antimicrobial agents (BBL, USA) by using the agar disk diffusion method. S. aureus isolates were isolated 58 (39.2%) strains of 148 samples: wound 64.7% (11/17), genital discharge 37.0% (37/100) and nasal discharge 32.2% (10/31). Almost isolates showed high resistance to spectinomycin, sulfonamides, erythromycin, tetracyelin, ciprofloxacin and penicillin. These results may provide the basic information to establish strategies for treatment and prevention of reproductive and respiratory disease in Thoroughbred horses in Korea.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.87-91
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• 2007

Objectives : This experimental study was performed to investigate the continuous anti-bacterial potency of Jinpi-san on cultivation of Staphylococcus species(S. aureus, S. epidermidis) that induce eye disease. Methods : Minimal inhibitory concentration(MIC) was measured by dropping to 50${\mu}$l diluted Jinpi-san(100%, 10%, 1%, 0.1%) on S. aureus, S. epidermidis that were cultivated from 2 to 6 days. Anti-bacterial potency was measured by the size of inhibition zone with change of volume(20${\mu}$l, 30${\mu}$l, 40${\mu}$l, 50${\mu}$l). Results : 1. Anti-bacterial potency of Jinpi-san on S. aureus was appeared in 100% and increased on 6 days. Anti-bacterial potency with change of volume was increased in propotion to increase volume. Anti-bacterial potency of Jinpi-san on S. aureus was appeared continuous. 2. Anti-bacterial potency of Jinpi-san on S. epidermidis was appeared in 100%, 10%, 1% on 2 days and in 100%, 10% on 6 days. In 100% Jinpi-san, Anti-bacterial potency of 6 days was increased, in 10%, Anti-bacterial potency of 2 days was increased, in 1%, Anti-bacterial potency of 6 days was disappear. Anti-bacterial potency with change of volume was increased in propotion to increase volume except for 20${\mu}$l of 6days and increased on 6 days, but bacteria was increased. Anti-bacterial potency of Jinpi-san on S. epidermidis wasn't appeared continuous. Conclusions : Anti-bacterial potency of Jinpi-san on cultivation of S. aureus was showed continuous, but on cultivation of S. epidermidis was not showed continuous.