• Research in Plant Disease
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• v.14 no.3
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• pp.165-170
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• 2008

One hundred and three isolates of Xanthomonas oryzae pv. oryzae in Korea were evaluated for their virulence on four near-isogenic lines (NILs) containing a single resistance gene, and Korean differential varieties. The resistant gene backgrounds of Cheongcheongbyeo, Pungsanbyeo, Hangangchalbyeo, Milyang42 were not completely understood and they were not suited for the classification of X. oryzae pv. oryzae. Four NILs, IRBB101, IRBB103, IRBB105, and IRBB107 were difference for characterizing races of X. oryzae pv. oryzae because they have a single resistance gene. These NILs may be useful differential set in examining pathogenic races of X. oryzae pv. oryzae in Korea. Based on the virulence of 103 isolates to new differential varieties, they were classified into 3 races.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.61-68
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• 1987

This study was conducted to determine the microorganisms inhabitating in cow genitalia and their antimicrobial drug susceptibility. During the period between July, 1985 and February, 1986, a total of 111 cow genitalia, 58 from Korean native and 53 from dairy cow, were sampled at three abattoirs. Gross pathological examination and bacterial isolation and identification were performed from the genital samples. In addition antimicrobial drug susceptibility test for the microorganisms isolated, some synergistic activity among drugs were examined on the major organism isolated from the cases of endometritis and pyometra. The results are summerized as follows: 1. Among the bacteria isolated from the genitalia, Staphylococcus spp., C. pyogenes, E. coli, Proteus spp., Streptococcus spp., Bacillus spp. were most frequently isolated whereas the genera of Pasteurella, Pseudomonas, Klebsiella and Yersina were detected far less frequently. 2. In Korean native cow the genera of Straphylococcus and Steptococcus were more isolated than dairy cow while in dairy cow the genera of Corynebacterium, Proteus, Escherichia were more of ten isolated than Korean native cow. 3. From cow genital organs showing lesions of endometritis and prometra, C. pyogenes was most frequently isolated, the isolation rate being 60 percent, and follow by Staphylococcus spp., Proteus spp., E. coli and Pasteurella spp. in the order. 4. Antimicrobial drug susceptibility test conducted on the major organisms isolated showed that all the isolates were susceptible to gentamicin, cephalosporin and sulfisoxazole, but resistant to tetracycline and penicillin. 5. Twenty-nine isolates of C. pyogenes were submitted to the synergistic activity test of cephalosporin, kanamycin and streptomycin with penicillin. Synergists were demonstrated in 90 percent, 31 percent and 27 percent of isolates examined by the combined use of penicillin and cephalosporin, penicillin and kanamycin, penicillin and streptomycin, respectively. About 10 percent of the isolates were found to be indifferent by the synergism test.

• Korean Journal of Veterinary Research
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• v.52 no.3
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• pp.169-176
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• 2012

Probiotics colonize the intestines and exert an antibacterial effect on pathogens. Therefore, probiotics could be used as a preventive agent against lethal infections. To isolate probiotic microorganisms, 116 bacterial strains were isolated from healthy cow's milk and were subjected to Gram-stain, morphology and biochemical analyses, Vitek analysis, and 16S rRNA analysis. One of the strains identified as Bacillus (B.) thuringiensis 87 was found to grow very well at pH 4.0~7.0 and to be resistant to high concentrations of bile salts (0.3~0.9% w/v). B. thuringiensis was susceptible to the antibiotics used in the treatment of bovine mastitis, yet it exhibited an antimicrobial effect against Staphylococcus (S.) aureus 305. Moreover, it protected mice from experimental lethal infections of E. coli O55, Salmonella typhimurium 01D, and S. aureus 305 through a significant induction of interferon-${\gamma}$, even at four-week post-administration of B. thuringiensis. Although oral administration of B. thuringiensis 87 did not provide significant protection against these lethal challenges, these results suggest that B. thuringiensis 87 could be a feasible candidate as a probiotic strain.

• Journal of Korean society of Dental Hygiene
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• v.10 no.6
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• pp.1095-1105
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• 2010

Objectives : This paper is designed to help the public prevent their future dental caries, based on the studies of xylitol about it's efficacy and effectiveness, and its appropriate usage. Methods : This study of xylitol on the basis of existing research papers and literature is not only to learn about the mechanism of what xylitol acts, but also to search the effectiveness of incompleteness of xylitol-containing foods, bacterial infection between xylitol and mother-baby, and the side-effects of xylitol. Results : 1. Xylitol's continuous intake of teeth effects the decrease of calculus amount, cleanness of teeth, as well as the remineralization process. The xylitol effect varies depending on the weight of xylitol, which has no effect on root caries. 2. Mouth gargle solution is higher resistant against acids; recalcification is significantly reduced; and remineralization effect represents. 3. It is reported that regular consumption of xylitol by mothers just during two years after birth has significantly decreased the spread possibility of mutans streptococcei. 4. The reduction of dental caries by xylitol is happened by its restraining the growth of bacteria resource caries, with their presence in amount of uncontrolled growth. 5. When a small amount of eating xylitol is absorbed slowly into gastrointestinal tract, being followed by glucose metabolism in the liver, while its excessive amount of eating can cause gastrointestinal problems. Conclusion : Dental hygienists should be required to provide dental information to the public on the basis of academic knowledge. In situation that one is not yet sure of xylitol on solid and multifaceted researches, there must be needed more accurate and detailed reviews on the side-effects of xylitol and the overall impact on the oral environments.

• Preventive Nutrition and Food Science
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• v.18 no.2
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• pp.104-110
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• 2013

Presence of Helicobacter pylori is associated with an increased risk of developing upper gastrointestinal tract diseases. Antibiotic therapy and a combination of two or three drugs have been widely used to eradicate H. pylori infections. Due to antibiotic resistant drugs, new drug resources are needed such as plants which contain antibacterial compounds. The aim of this study was to investigate the ability of GutGard$^{TM}$ to inhibit H. pylori growth both in Mongolian gerbils and C57BL/6 mouse models. Male Mongolian gerbils were infected with the bacteria by intragastric inoculation ($2{\times}10^9$ CFU/gerbil) 3 times over 5 days and then orally treated once daily 6 times/week for 8 weeks with 15, 30 and 60 mg/kg GutGard$^{TM}$. After the final administration, biopsy samples of the gastric mucosa were assayed for bacterial identification via urease, catalase and ELISA assays as well as immunohistochemistry (IHC). In the Mongolian gerbil model, IHC and ELISA assays revealed that GutGard$^{TM}$ inhibited H. pylori colonization in gastric mucosa in a dose dependent manner. The anti-H. pylori effects of GutGard$^{TM}$ in H. pylori-infected C57BL/6 mice were also examined. We found that treatment with 25 mg/kg GutGard$^{TM}$ significantly reduced H. pylori colonization in mice gastric mucosa. Our results suggest that GutGard$^{TM}$ may be useful as an agent to prevent H. pylori infection.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.4
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• pp.457-464
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• 2005

The optimal concentration of ethanol to separate a high quantity of propolis was $60\%$ but that for the best flavonoids extraction was $80\%$ We compared the yields of propolis from different countries. In this study we used $60\%$ ethanol concentration as a standard. The yield of propolis was proportional to the contents of flavonoids. Namely, Polish propolis which showed the highest yield with $56\%$ by the extraction with $60\%$ ethanol revealed also the highest flavonoids content with $3.49\%$ among all the samples tested The major constituents of propolis differed from country to country. It has been suggested that the different geographical origin influenced the efficacy and the constituents of propolis. Antibacterial activity of ethanol extracted propolis from different countries was tested against 6 microbial strains of type cultures including Gram-positive (Staphylococcus aureus, Streptococcus uberis, Streptococcus agalactiae) and Gram- negative bacteria (Klebsiella pneumoniae, Proteus vulgaris and E coli) in vitro. Propolis extract showed anti-microbial activity against all the tested bacterial strains. In addition, propolis was sensitive to E coli which was resistant to broad spectrum antibiotics like ampicillin. These results showed that propolis may substituted for commercial antibiotics. The efficiency of anti-microbial activity of the propolis was slightly higher in $80\%$ than $97\%$ ethanol extract.

• Molecules and Cells
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• v.43 no.8
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• pp.694-704
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• 2020

HslUV is a bacterial heat shock protein complex consisting of the AAA+ ATPase component HslU and the protease component HslV. HslV is a threonine (Thr) protease employing the N-terminal Thr residue in the mature protein as the catalytic residue. To date, HslUV from Gram-negative bacteria has been extensively studied. However, the mechanisms of action and activation of HslUV from Gram-positive bacteria, which have an additional N-terminal sequence before the catalytic Thr residue, remain to be revealed. In this study, we determined the crystal structures of HslV from the Gram-positive bacterium Staphylococcus aureus with and without HslU in the crystallization conditions. The structural comparison suggested that a structural transition to the symmetric form of HslV was triggered by ATP-bound HslU. More importantly, the additional N-terminal sequence was cleaved in the presence of HslU and ATP, exposing the Thr9 residue at the N-terminus and activating the ATP-dependent protease activity. Further biochemical studies demonstrated that the exposed N-terminal Thr residue is critical for catalysis with binding to the symmetric HslU hexamer. Since eukaryotic proteasomes have a similar additional N-terminal sequence, our results will improve our understanding of the common molecular mechanisms for the activation of proteasomes.

• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.493-497
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• 2013

This study was designed to analyze the chemical composition of essential oil in 'Shiranuhi' immature fruit and to test their biological activities. 'Shiranuhi' immature essential oils (SIEO) were obtained by steam distillation from fruits collected from Jeju Island and were analyzed using gas chromatograph (GC)-flame ionization detectors (FID) and GC-MS. Fourteen components were identified in the essential oil. Limonene (75.21%) and terpineol (8.68%) were the major components in SIEO. Since acne vulgaris is the combined result of a bacterial infection and the inflammatory response to that infection, we examined whether SIEO possessed antibacterial against skin pathogens. As a result, SIEO showed excellent antibacterial activities against drug-susceptible and -resistant Propionibacterium acnes and Staphylococcus epidermidis, which are acne-causing bacteria. In this study, SIEO was examined on DPPH radical scavenging activities, which showed moderate antioxidant activity ($SC_{50}$, $15.36{\mu}L/mL$). In order to determined whether SIEO can be safely applied to human skin, the cytotoxicity effects of SIEO were determined by colorimetric MTT assays in normal human fibroblasts and keratinocyte HaCaT cells. They exhibited low cytotoxicity at $0.5{\mu}L/mL$ in both celllines. Based on these results, we suggest the possibility that essential oil of 'Shiranuhi' maybe considered as an antibacterial and antioxidant agent.

• Journal of Microbiology
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• v.44 no.3
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• pp.363-368
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• 2006

In this study, native Byadyrhizobium strains were isolated from the host plant, Glycine max, harvested from fields in Madhya Pradesh, India, and were typed by Iytic rhizobiophages. Eight indigenous (Soy2, ASR011, ASR031, ASR032, MSR091, ISR050, ISR076 and ISR078) and two exotic strains (USDA123 and CB1809), all of which evidenced a distinct reaction with six phages, were employed in this study. The symbiotic interaction of these strains was studied initially using soybean cultivar JS335 in a sand culture in a controlled environment, and the efficiency was assessed based on the nodule number, nodule dry weight, plant dry weight, nitrogenase activity, and total accumulation of N per plant. Symbiotic effectiveness was found to be highest with the native phage-sensitive isolate ASR011, whereas it was at a minimum with the phage-resistant isolates, ISR050 and ISR078. Additionally, the effectiveness of these strains was evaluated using six soybean cultivars belonging to different maturity groups; namely, Brags, Lee, Pusa20, PK416, JS33S and NRC37. Analysis of variance data evidenced significant differences due to both symbionts, for the majority of the tested parameters. The CB1809, USDA123, and ASR011 strains evidenced relatively superior symbiotic effectiveness with soybean cultivars Brags, Lee and JS335. Strain ISR078 evidenced no significant responses with any of the cultivars. The ASR031 strain performed moderately well with all tested cultivars. The symbiotic response of all the strains was quite poor with cultivar PK416. Our studies showed that a significant relationship existed between the phage sensitivity and symbiotic efficiency of the bacterial strains with the host-cultivars.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.66-73
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• 1993

Psychrotrophic bacterial strains utilizing crude oil as their sole carbon and energy sources were isolated from Antarctic soil and sea sediments. One of the strains named AI-I showed the hightest activity for emulsification of crude oil and the best growth. This strain was identified as Acinetobacter calcoaceticus. A. calcoaceticus AI-I strain contains a plasmid (OCT plasmid) which was related to the utilization of alkane compounds. The molecular weight of this plasmid was estimated to be about 110 Md by agarose gel electrophoresis. The cured strain of A. calcoaceticus AI-I strain (OCT ) was not able to utilize normal hydrocarbon compounds ($C_6C_{17}$) as carbon and energy sources. A. ca/coaceticus AI-1 was resistant to ampicillin and sensitive to streptomycin, kanamycin, chloramphenicol, tetracycline. The results suggested that this strain carries a plasmid (OCT) responsible for oil utilization which is quite stable and might be concerned with antibiotics resistancy.