• Journal of Life Science
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• v.22 no.8
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• pp.1114-1119
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• 2012

Bacteria are frequently contaminated during the collection and processing procedures of boar semen. Of the contaminants, Stenotrophomonas (S.) maltophilia is a Gram-negative bacterium that is widely distributed in a variety of habitats. Although PCR assays have been developed for the detection of S. maltophilia, they cross-react with some species of Xanthomonas. In this study, we designed a primer set for the detection of S. maltophilia in order to target the chiA (GenBank accession no. NC_010943) gene. The specific PCR products were amplified from S. maltophilia only, not from other tested strains that are frequently found in semen. The detection limit of the PCR was $1.5{\times}10^3$ CFU/ml with pure-cultured S. maltophilia and $1.5{\times}10^4$ CFU/ml with S. maltophilia spiked in semen. Twenty-six (5.9%) S. maltophilia were isolated from 440 semen samples. The PCR results exhibited 98.9% agreement with a comparison of S. maltophilia isolation. Also, the sensitivity and specificity of the PCR were 100% and 98.7%, respectively. In the antimicrobial susceptibility test, S. maltophilia isolates were highly susceptible to enrofloxacin and florfenicol, while the majority of them were resistant to amoxicillin/clavulanic acid, apramycin, ceftiofur, penicillin, and spectinomycin. These results indicated that the PCR using the chiA gene was proven to be reliable and effective for the detection of S. maltophilia with high levels of sensitivity and specificity.

• Korean Journal of Microbiology
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• v.48 no.3
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• pp.180-186
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• 2012

Pseudomonas aeruginosa, a Gram-negative bacterium, is an ubiquitous and opportunistic human pathogen, which expresses many virulence factors through quorum sensing (QS) regulation. QscR, one of the QS signal receptors of P. aeruginosa, has unique features that make it possible to distinguish QscR from other QS receptors. In the present study, we focused on amino acid residues responsible for such a broad signal specificity of QscR. Thus we constructed mutant QscRs: $QscR_{T72I}$, $QscR_{R132M}$, and $QscR_{T140I}$ by substituting $72^{nd}$ threonine, $132^{nd}$ arginine, and $140^{th}$ threonine residues with isoleucine, methionine, and isoleucine, respectively by site-directed mutagenesis. When we examined the activity of these mutant QscRs, $QscR_{R132M}$ failed to respond to N-3-oxododecanoyl homoserine lactone (3OC12-HSL), but $QscR_{T72I}$ and $QscR_{T140I}$ remained the ability to respond to 3OC12-HSL despite much reduction of the sensitivity. When we treated a variety of acyl-HSLs with different structure, $QscR_{T72I}$ and $QscR_{T140I}$ showed better responsiveness to N-decanoyl HSL (C10-HSL) or N-dodecanoyl HSL (C12-HSL) that has no oxo-moiety at $3^{rd}$ carbon of acyl group than to 3OC12-HSL, and $QscR_{R132M}$ showed no responsiveness to any acyl-HSLs tested here. In addition, $QscR_{T72I}$ and $QscR_{T140I}$ were inhibited by 5f, a QscR inhibitor as similarly as wild type QscR was. These results suggest that while the $130^{th}$ arginine is crucial in both activity and acyl-HSL binding of QscR, the $72^{nd}$ and $140^{th}$ threonines are important in the activity, but they are little responsible for the discrimination of acyl-HSLs or competitive inhibitor.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.344-351
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• 2016

A marine bacterium, designated as strain 50C-3, was isolated from a seawater sample collected from the East Sea of South Korea. The strain is a Gram-negative, aerobic, yellow colored polar-flagellated bacterium that grows at $20-50^{\circ}C$ and pH 5.5-8.5. Optimal growth occurred at $40-50^{\circ}C$, at pH 6.5-7.5, and in the presence of 2% (w/v) NaCl. Based on 16S rRNA gene sequence similarity, the isolate was considered to represent a member of the genus Ruegeria. The result of this analysis showed that strain 50C-3 shared 99.4% and 96.98% sequence similarity with Ruegeria intermedia CC-GIMAT-$2^T$ and Ruegeria lacuscaerulensis ITI-$1157^T$, respectively. Furthermore, strain 50C-3 showed clear differences from related strains in terms of several characteristics such as motility, carbon utilization, enzyme production, etc. The DNA G+C content was 66.7 mol%. Chemotaxonomic analysis indicated ubiquinone-10 (Q-10) as the predominant respiratory quinone. Based on phenotypic, chemotaxonomic, and phylogenetic characteristics, the isolate represents a novel variant of the Ruegeria intermedia CC-GIMAT-$2^T$, for which we named Ruegeria sp. 50C-3 (KCTC23890=DSM25519). Strain 50C-3 did not produce cellulase and agarase, but produced alkaline phosphatase, ${\alpha}$-galactosidase, and ${\beta}$-galactosidase. The three enzymes showed stable activities even at $50^{\circ}C$ and thus regarded as thermostable enzymes. Especially, the ${\beta}$-galactosidase activity enhanced by 1.9 times at $50^{\circ}C$ than that at $37^{\circ}C$, which may be very useful for industrial application.

• Journal of Life Science
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• v.21 no.3
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• pp.375-384
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• 2011

This study was performed to evaluate the antioxidant and antimicrobial activity of methanol extract from Rosmarinus officinalis L. and its fractions. The ethyl acetate fraction of rosemary had a higher antioxidant activity in both DPPH ($3.22\;{\mu}g/ml$) and ABTS ($5.05\;{\mu}g/ml$) compared to other extracts and fractions. Based on the results of the FRAP assay, the ethyl acetate fraction of rosemary showed a value of $5.9{\pm}0.3\;{\mu}M/{\mu}g$, and buthanol fraction and rosmarinic acid exhibited values of $4.8{\pm}0.2\;{\mu}M/{\mu}g$ and $5.1{\pm}0.1\;{\mu}M/{\mu}M$, respectively. Measurements of the antimicrobial activities of the extracts, fraction against gram positive, negative bacteria revealed that the methanol extract, hexane, ethyl acetate, and chloroform fraction of rosemary caused Staphylococcus aureus and Escherichia coli to form clear zones greater than 12 mm. Furthermore, the methanol extract and chloroform fraction showed high antibacterial activity, with inhibition zone exceeding 13 mm. The methanol extract and chloroform fraction of rosemary had broad antimicrobial spectrums and low MIC values. Therefore, methanol extracts of rosemary could serve as potential antibacterial agents to inhibit pathogen growth in food and hand sanitizers.

• Journal of Life Science
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• v.20 no.6
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• pp.845-852
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• 2010

Our previous study showed that lungs infected by Pseudomonas, a gram-negative bacteria, produce prostaglandin $D_2$ ($PGD_2$) and prostaglandin $E_2$ ($PGE_2$), the two major prostanoids generated by cyclooxygenase-2 (COX-2), and that the ratio of $PGD_2$ and $PGE_2$ can affect the outcome of the bacterial lung infection. In this study, we sought to uncover the mechanism that determines the ratio of $PGD_2$ and $PGE_2$ produced in lung inflammation. When treated with lipopolysaccharide (LPS), primary alveolar macrophages, extracted from mouse lung, more $PGE_2$ was produced than $PGD_2$, whereas MH-S, a murine alveolar macrophage cell line, produced more $PGD_2$ than $PGE_2$ in a similar experiment. Western blot analyses showed that the kinetics of COX-2 expression in both cell types is similar and epigenetic silencing of COX-2 expression did not affect expressions of lipocalin-PGD synthase (L-PGDS) and PGE synthase (mPGES-1), major enzymes synthesizing $PGD_2$ and $PGE_2$ in inflammation, respectively, indicating no effect of COX-2 on expressions of the two enzymes. Expressions of L-PGDS and mPGES-1 were also similar in both cell types, suggesting no effect of the two key enzymes in determining the ratio of $PGD_2$ and $PGE_2$ in these cells. A single intraperitoneal injection of LPS to C57BL/6 mice induced COX-2 expression and, similar to alveolar macrophages, produced more $PGE_2$ than $PGD_2$ in the lung. These results suggest that the differential expressions of $PGD_2$ and $PGE_2$ in the lung reflect those in alveolar macrophages and may not be directly determined by the enzymes responsible for $PGD_2$ and $PGE_2$ synthesis.

• Journal of dental hygiene science
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• v.4 no.1
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• pp.7-11
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• 2004

The purpose of this study was to investigate the distribution of microorganisms and the degree of contamination in the air of the dental clinics and to offer basic data as to the contamination of medical equipment and the prevention of the clinics. With this in mind, the researcher gathered air samples from the waiting rooms and medical offices of nine dental clinics in the city of J, South Korea with the use of a method of natural inattention and an air sampler and cultivated the samples on the plain table and drew from it bacteria falling and separated and sorted out the colony with the help of ATB and detected the distribution of the germs. The results are following, The number of bacteria falling in the air of the dental clinics was less than 10(CFU/Plate) with the exception of one dental clinic. This implies that they fit in with standards for hygiene. The number of bacteria falling in the air of the medical offices was less than 10(CFU/Plate) with the exception of one dental clinic. This implies that they fit in with standards for hygiene. The survey on the detection of staph. aureus reveals that all the dental clinics with the exception of B dental clinic proving to be positive had non-pathogenic staphylococci detected. The survey on the detection of pathogenic gram negative bacilli indicates that all the dental clinics but one were none detected. The survey on the distribution of germs shows that germs in 7 out of 9 dental clinics were none detected, and that they in four out of 9 waiting rooms were none detected. All the germs detected in the others were mostly non-pathogenic. The study shows that all the subject dental clinics but one were hygienically controlled and that there was a difference in accordance with cleaning and sterilization. This means that dental clinics should be equipped with systematic programs for cleaning and sterilization designed to prevent infection.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.403-411
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• 2009

This study was conducted to gather the basic data on the increase of utilization for the Japanese staunton vine (Stauntonia hexaphylla), native plants which were grown in the southern districts in Korea. We have also determined their partial physical and chemical compositions and their physiological activities. Vitamin C contents in fruit skin was 85.23 mg/100 g, and that in flesh was 61.67 mg/100 g. Total amino acids contents in fruit skin increased much more by 762.72 mg/100 g DW compared to that in flesh by 434.05 mg/100 g DW. Inorganic matter contents were more increased in the fruit skin (108.48 mg/$\ell$) and its main components were K (76.53 mg/$\ell$), Ca (20.20 mg/$\ell$) and Mg (6.22 mg/$\ell$). Total phenol compound and flavonoid contents in 1,000 mg/$\ell$ methanol extracts were 7.3-9.6 mg/$\ell$ and 5.1-6.7 mg/$\ell$. Nitrite radical scavenging activity in 4,000 mg/$\ell$ methanol extracts of fruit skin and flesh for Stauntonia hexaphylla were 79.5% and 77.8%, however, that in seeds was 17.1%. Overall mushroom tyrosinase inhibition activity (% of control) was less than 10.8%. Anti-microbial activities of methanol extracts from the fruit skin against the gram negative and positive microbial strains were not significant in the lower concentration of extracting solution, however, that from flesh and seeds in terms of the inhibition diameter were $8.91{\sim}12.25\;mm$.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.279-284
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• 2008

This study was performed to investigate effect of different soil managements on physical properties and microbial activities in volcanic ash citrus orchard soil. Experiment plots had managed to control weeds on soil for 4 years with clean cultivation (CCM) used with herbicide, natural sod cultivation (NSCM), kentucky blue grass sod cultivation (KBG). Soil samples were taken on October, in both 1998 and 2000 from 3 experimental plots. In NSCM, Soil hardness was lower at 11.8 mm than in CCM. And water stable Aggregation coefficient(>0.5 mm) was high at 26.7% compared with CCM. Soil bulk density and porosity showed no significant among the treatments. Soil acid phosphatase was high in sod cultivation plots and the amount of microbial biomass C was about twice higher at $525.4mg\;kg^{-1}$ in KBG than in CCM. Conclusionally, Sod cultivation improved soil physical properties such as aggregation, hardness and increased microbial activities compared with clean cultivation in citrus orchard soil. Soil total PLFA, acid phosphatase, and microbial biomass C contents were investigated on May in nonvolcanic ash citrus soil. Soil samples were collected at 5 sites each; convention cultivation grown with herbicide, natural sod cultivation grown with 1/2 chemicals, organic cultivation. That sites have been managed for 5 years over. PLFA contents were two times higher at $112.2n\;mol\;g^{-1}$ in organic cultivation than in convention cultivation. According to the PLFA indicator, Gram negative bacteria and actinomycetes in organic cultivation were high compared with convention cultivation, which were at 15.1%, 6.6%, respectively. Soil microbial biomass C contents was about twice higher in organic cultivation than in convention cultivation. Soil acid phosphatase was high at 17.6% in organic cultivation compared with convention cultivation.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.104-111
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• 1993

Background: Gram-negative bacterial endotoxin induced septicemia is known to be a leading cause in the development of adult respiratory distress syndrome(ARDS). The mechanism of endotoxin induced lung injury is mainly due to the activated neutrophils which injure the capillary endothelial cells by releasing oxidant radical and resulted in pulmonary edema. We studied the change of antioxidant enzyme in the case of large or small, intermittant dose of endotoxin infused rat lungs. Methods: Endotoxin was given to the rat through the peritoneal cavity in the dose of 7 mg/kg body weight in the large dose group and 1 mg/kg for 10 days in the small dose group. Bronchoalveolar lavage (BAL) was done and rats were killed at 6, 12, 24 hours after single endotoxin injection in the large dose group and 3, 7, 10 days after daily endotoxin injection for 10 days in the small dose group. The lungs were perfused with normal saline through the pulmonary artery to remove the blood and were homogenized in 5 volume of 50 mM potassium phosphate buffer containing 0.1 mM EDTA. After centrifuging at 100,000 g for 60 minute, the supernatent was removed and stored at $-70^{\circ}C$ until measuring for superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and protein. Results: We observed the following results. 1) The lung wet/dry weight ratio and albumin concentration in the BAL fluids were increased to peak at 12 hours and neutrophil number in the BAL fluids were peak at 6 hours after endotoxin injection in the large dose group. 2) Cu, Zn SOD (IU/mg protein) was significantly decreased after 6, 12 hours after endotoxin injection in the large dose group. 3) There were no singnificant change in the level of Mn SOD, catalase, GSH-Px after endotoxin injection in both groups. Conclusion: Endotoxin in the large dose group produced the acute pulmonary edema and decreased the Cu, Zn SOD in the lung tissue after injecting endotoxin at 6 and 12 hours. These phenomenon may be due to the cell membrane damage by endotoxin. Further research would be necessary whther giving SOD by intratracheal route or method to increase the synthesis of SOD may lessen the acute lung injury by endotoxin.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.250-260
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• 2012

In the present study, the antioxidative and antibacterial activities of Artemisia princeps Pampanini (A. princeps Pamp.) extract were investigated. The ethyl acetate fraction of A. princeps Pamp. showed the most prominent free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC_{50}=12.27{\mu}g/mL$). Reactive oxygen species (ROS) scavenging activities ($OSC_{50}$) of A. princeps Pamp. extract on $Fe^{3+}-EDTA/H_2O_2$ systems were investigated using a luminol-dependent chemiluminescence assay. The ethyl acetate fraction of the extract ($OSC_{50}=0.33{\mu}g/mL$) had a 5 times greater ROS scavenging activity than L-ascorbic acid ($1.50{\mu}g/mL$), known as a water soluble antioxidant. The cellular protective effects of fractions of A. princeps Pamp. on the rose-bengal sensitized photohemolysis of human erythrocytes were examined. The aglycone fraction of extracts suppressed photohemolysis in a concentration dependent manner. The inhibitory effects of A. princeps Pamp. extract on tyrosinase were investigated to assess their whitening efficiency. The ethyl acetate fraction demonstrated a 7 times higher tyrosinase inhibitory effect ($IC_{50}=29.20{\mu}g/mL$) than albutin, known as a whitening agent. The antibacterial activity of ethyl acetate fractions against various normal skin flora were measured. The results showed that the antibacterial activity of the fraction was the highest on Staphylococcus aureus, Bacillus subtilis, and Propionibacterium acnes. Antioxidant substances were isolated and purified from the ethyl acetate fractions. Eupatilin and jaceosidin were identified. These results indicate that the extract/fractions of A. princeps Pamp. can function as antioxidant and/or antibacterial agents for the skin.