• Korean Journal of Microbiology
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• v.40 no.4
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• pp.286-294
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• 2004

Between 1997 and 1998 in Korea, 56 isolates of Escherichia coli were obtained from pig suffering diarrhea. Among those, 38 isolates that showed the hemolytic activity, antimicrobial resistance, and toxin production were studied. Among 38 isolates, thirty-six isolates $(94.7\%)$ were resistant to tetracycline, 27 isolates $(71.0\%)$ were resistant to ampicillin, 26 isolates $(68.4\%)$ were resistant to chloramphenicol, and 21 isolates $(55.2\%)$ were resistant to trimethoprim, while none was resistant to aztreonam, amikacin, and norfloxacin. Among these iso­lates, 21 isolates $(55.3\%)$ were multiple drug resistant to at least four different class antimicrobial agents. Extended spectrum $\beta-lactamase$ producing isolates were not detected in the double disk synergy test. In these hemolytic Escherichia coli, heat-stable enterotoxin $(89.5\%)$ was the most prevalent toxin, followed by vero­toxins $(47.4\%),$ and then heat-labile enterotoxin $(31.6\%).$ Except 8 isolates $(21.0\%)$ which produced ST only, 12 isolates $(31.6\%)$ produced ST and LT, 13 isolates $(34.2\%)$ produced ST, VT, and VTe, and 5 isolates $(13.2\%)$ produced VT and VTe. However, none produced all 4 types of toxin, simultaneously. The predominant serotype could not be determined by the agglutination method. Sixteen isolates $(42.1\%)$ were strongly adhered to T-24 bladder cell and 17 isolates $(44.7\%)$ were to Caco-2 intestinal cell. Especially, 11 strains $(28.9\%)$ were evaluated as strongly adhesive to both T-24 cells and Caco-2 cells. Genes for toxin and the antimicrobial resistance were transferred to clinical isolates of Escherichia coli from human urine by the filter mating method. Results suggest the possibility that antimicrobial resistance and toxin can be transferred from animals to humans by direct con­tact of resistant bacteria as well as gene transfer, although there was no correlation between toxin production, adherent activity, and antimicrobial resistance among hemolytic E. coli isolated from pig suffering diarrhea.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.4
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• pp.345-354
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• 2000

TGF-${\beta}_1$ is a potent chemotactic factor for inflammatory cells and fibroblasts. It also stimulates the celluar source and components of extracellular matrix and the production of proteinase inhibitors. Collectively, these biologic activities lead to the accumulation and stabilization of the nascent matrix, which is vital to wound healing. The objective of this study is to investigate production of TGF-${\beta}_1$ in vitro fibroblast culture in the presence of Staphylococcus enterotoxin B(SEB) and/or lipopolysaccharide(LPS) and to elucidate the role of TGF-${\beta}_1$ which may be responsible for wound healing. The fibroblasts were originated from facial dermis and hypertrophic scar in 26 year-old male patient. In the presence of LPS($0.01{\mu}g$, $0.1{\mu}g$, $1.0{\mu}g$), SEB($0.01{\mu}g$, $0.1{\mu}g$, $1.0{\mu}g$) respectively, cells($5{\times}10^3ml$) were cultivated in vitro. At 1, 3, and 5 days after incubation, cells were counted. Also, cells($2.5{\times}10^5ml$) were cultivated in EMEM with LPS(0.01, 0.1 and $1.0{\mu}g$), SEB(0.01, 0.1 and $1.0{\mu}g$) respectively and LPS($0.1{\mu}g$) and SEB($0.1{\mu}g$) in combination for 24, 48, and 72 hours respectively. Culture supernatants were harvested at 1, 2, and 3 days after incubation period and triplicate culture supernatants were pooled and TGF-${\beta}_1$ was assayed in duplicate. The results were as follows. 1. In facial dermal fibroblast induced with SEB and LPS respectively or in combination, the suppression of cell proliferation occurred very significantly at 1 day after incubation, compared with the control. In SEB exposure, the production of TGF-${\beta}_1$ was decreased very significantly at 1 day after incubation, compared with the control. However, in LPS, SEB and LPS exposure, the production of TGF-${\beta}_1$ was increased very significantly at 1 day after incubation, compared with the control. 2. In hypertrophic scar fibroblast induced with SEB and LPS respectively or in combination, the suppression of cell proliferation did not occur at 1 day after incubation, compared with the control. In SEB and LPS exposure in combination, the production of TGF-${\beta}_1$ was increased very significantly at 1 day after incubation, compared with the control. However, the production of TGF-${\beta}_1$ did not occur in SEB and LPS exposure respectively. In conclusion, the concentration of bacterial toxins and the incubation period correlated with cell proliferation and production of TGF-${\beta}_1$ very significantly and both fibroblasts have different phenotype each other in this regard. This data suggest that the significant production of TGF-${\beta}_1$ may develope abnormal wound healing associated with tissue fibroproliferative disorder, such as hypertrophic scar and keloid formation.

• Journal of Life Science
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• v.11 no.2
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• pp.181-189
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• 2001

Cytokines are hormone-like proteins which mediate and regulast inflammatory and immune responses. Transforming growth factor -$\beta$1(TGF-$\beta$) plays an important role in the control of the immune response and wound healing, and in the development o various tissues and organs, Nitric oxide(NO) is major messenger molecule regulating immune function and blood vessel dilation and serving as a neurotransmitter in the brain and peripheral nervous system. Also, NO is to be a potent mutagen that cause mutation in the p53 tumor suppressor gene in early phases of human gastric carcinogenesis. The purpose of this study was to investigate the effect of Helicobacter phlori lystes, lipopolysaccharide (LPS), and Staphylococcus enterotoxin B(SEB) on production of TGF-$\beta$1 and NO by human fibroblasts. Primary cultured human fibroblasts were incubated with H. pylori lysates(Hp), LPs, SEB, Hp+LPS, Hp+SEB, Hp+LPS+SEB. Cultured supernatants that were collected at 24, 48 and 72 hr were assessed for TGF-$\beta$1 by enzyme-linked immunosorbent assay and NO production by quantification of nitrite ion. TGF-$\beta$1 production in fibroblasts exposed with Hp, LPS or SEB for 48 hrs was enhanced, but for 72 hrs inhibited. Its production by doble exposure such as Hp+LPS, Hp+SEB, Hp+LPS+SEB was lowered in comparison with single exposure of Hp in cases of 24 and 48 hrs incubation, but for 72 hrs decreased in Hp vaculoating toxin(+), increased in Hp vacuolating toxin(-). No production in fibroblasts increaed at all doses of LPS. But its production by exposure of SEB increased or decreased according to dose and incubation time. Also, NO production by Hp vacuolating toxin(+) increased at all doses, but its production by Hp vacuolating toxin(-) decreased. Its production by doble exposure such as Hp+LPS, Hp+SEB, Hp+LPS+SEB decreased in comparison with single exposure Hp Therefore, quantities pf TGB-$\beta$1 and NO released by human fibroblasts shows differences according to kinds of stimulants. Also, in care stimulated with same kinds of stimulants, its productions exhibit quantitative differences according to exposure times. These results suggest that the decreased of TGF-$\beta$1 in fibroblasts by mixed exposure with Hp producing vacuolating toxin and bacterial toxins such as LPS and SEB may effect negatively in healing of host tissue and increased of NO by infection oh H. pylori may related to the increased susceptibility for human gastric carcinogenesis.

• The Journal of the Korean Society for Microbiology
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• v.22 no.2
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• pp.125-130
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• 1987

The role of enteropathogenic Escherichia coli(EPEC) was evaluated in a group of children with endemic diarrhea admitted to Hanyang University Hospital in Seoul, Korea. EPEC was detected in fecal samples of 23% of 100 cases and 4.5% of 44 concurrent control children. The most commonly isolated EPBC strains were serogroups $O_{18a}O_{18c}:K_{77},\;O_{86a}:K_{61},\;O_{119}:K_{69},\;and\;O_{128}:K_{70}$. On testing for enterotoxin production, 6(26%) strains were isolated from 17% of the 100 diarrheal children and in 4.5% of the 44 well controls(P<0.05). Our study supports the concept that EPEC may be an important cause of endemic diarrheas in Korea.

• Journal of Preventive Veterinary Medicine
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• v.42 no.4
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• pp.148-156
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• 2018

Clostridium perfringens (C. perfringens) may cause diarrhea and enterotoxemia in adult and young livestock, leading to problems in the production and management of farms. Four hundred fecal samples were collected from 25 goat farms located in Gyeongsangbuk-do Province in the Republic of Korea. Sixteen C. perfringens strains were isolates from fecal samples, and the isolates were identified as type A (n=11) and type D (n=5). Additionally, ${\alpha}$- and ${\varepsilon}$-toxin genes were detected in 16 and 5 strains by PCR, respectively, and the enterotoxin gene was presented in 2 strains. The antibiotic susceptibility test was performed using the disk diffusion method and E-test method. In the disk diffusion method, ampicillin (n=16) and chloramphenicol (n=15) were highly susceptible to 16 C. perfringens isolates. In the E-test method, ampicillin, amoxicillin, amoxicillin/clavulanic acid and meropenem were susceptible to more than 14 of 16 C. perfringens isolates. This study indicates that administration of antibiotics such as ampicillin, amoxicillin/clavulanic acid and meropenem can prevent and treat C. perfringens infections in goats.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.233-241
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• 2005

Plants have considerable advantages for the production of antigenic proteins because they provide an inexpensive source of protein and an easy administration of vaccine. Since a publication describing edible plant vaccine of HBsAg in 1992, a number of laboratories around the world have studied the use of plants as the bioreactor to produce antigenic proteins of human or animal pathogens. Over the last ten years, these works have been mainly focused on three major strategies for the production of antigenic proteins in plants: stable genetic transformation of either the nuclear or plastid genome, or transient expression in plants using viral vectors. As many antigenic proteins have been expressed in tobacco, also several laboratories have succeeded to express genes encoding antigenic proteins in other crop plants: potato, tomato, maize, carrot, soybean and spinach. At present many works for the production of edible plant vaccine against bacteria-mediated diseases have mostly performed the studies of enterotoxins and adhesion proteins. Also the development of new-type antigens (pili, flagella, surface protein, other enterotoxin and exotoxin etc.) is required for various targets and more efficacy to immunize against microorganism pathogens. Many works mostly studied in experimental animals had good results, and phase I clinical trial of LTB clearly indicated its immunogenic ability. On the other hand, edible plant vaccines have still problems remained to be solved. In addition to the accumulation of sufficient antigen in plants, human health, environment and agriculture regulation should be proven. Also oral tolerance, the physiological response to food antigens and commensal flora is the induction of a state of specific immunological unresponsiveness, needs to be addressed before plant-derived vaccine becomes a therapeutic option.

• Journal of the Korean Society of Tobacco Science
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• v.33 no.1
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• pp.8-15
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• 2011

Genus Nicotiana has 76 species including N. tabacum. These plants are used not only as a material for cigarette manufacturing but also as ornamental plant, medicinal plant, poisonous substance plant, and bug repellent plant. N. tabacum is used as a main material for cigarette manufacturing with N. rustica. N. sylvestris and N. alata is used as ornamental plants because of their beautiful flowers and N. rustica is used for bug repellent or pesticide because of its high concentration of nicotine. N. glauca, a tree tobacco, is used for bio-fuel production. N. tabacum is used as a popular model plant system for degeneration, regeneration, and transformation. N. benthamiana is also used as a model system for foreign gene expression by agroinfiltration. The transformation ability of tobacco plant is a good target for molecular farming. Hepatitis B virus envelop protein, E. coli heat-labile enterotoxin, diabetes autoantigen, and cholera toxin B subunit were produced using tobacco plants. Secondary metabolites of tobacco include nicotine, anabasine, nornicotine, anatabine, cembranoid, solanesol, linoleic acid, rutin, lignin and sistosterol, and they are used for various medicine productions which cannot be produced by organic synthesis for their complicated structures. In conclusion, we have to understand the applicability of tobacco plant in detail and study to enlarge the usage of the plants.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1510-1517
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• 2012

To evaluate the probiotic potential of Bacillus polyfermenticus CJ6 isolated from meju, a Korean traditional soybean fermentation starter, its functionality and safety were investigated. B. polyfermenticus CJ6 was sensitive to all antibiotics listed by the European Food Safety Authority. The strain was also non-hemolytic, carried no emetic toxin or enterotoxin genes, and produced no enterotoxins. The resistance of B. polyfermenticus CJ6 vegetative cells and spores to simulated gastrointestinal conditions was high (60-100% survival rate). B. polyfermenticus CJ6 produced high amounts (0.36 g as a purified lyophilized form) of ${\gamma}$-polyglutamic acid (PGA). We speculate that the improved cell viability and the production of ${\gamma}$-PGA have a significant correlation. Adhesion of the strain to Caco-2 and HT-29 cells was weaker than that of the reference strain (Lb. rhamnosus GG), but it was comparable to or stronger than those of reported Bacillus spp. When B. polyfermenticus CJ6 spores were given orally to mice, the number of cells excreted in the feces was 4-fold higher than the original inocula. This suggests the inoculated spores propagated within the intestinal tract of the mice. This idea was confirmed by field emission scanning electron microscopy, which revealed directly that B. polyfermenticus CJ6 cells germinated and adhered within the gastrointestinal tract of mice. Taken together, these findings suggest that B. polyfermenticus CJ6 has probiotic potential for both human consumption and use in animal feeds.

• Korean Journal of Veterinary Research
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• v.39 no.5
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• pp.995-1005
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• 1999

Staphylococcus aureus is one of most prevalent intramammary pathogens and have characteristics which are not easily eradicated. Recently, to understand the sources and transmission of S aureus, many studies have focused on the subtyping of field isolate. This study was preformed to investigate the distribution pattern and characteristics of the isolates using phenotyping and genotyping. Samples were collected from milk of each udder, cow bodies (perianal region, vagina, tail, udder skin, sole) and environment (floor, liner, milker's hands, water, towel, insect) from 6 herds located in Kyung-gi province. Forty five strains of S aureus were isolated from 3 dairy herds (A, B, C) and were typed by hemolytic pattern, antibiotic resistant pattern, enterotoxin typing and PCR-based DNA fingerprinting. Slime productivity was also compared by each subtype to examine potential infectiousness. Of 45 strains, 41 were isolated from milk samples and 4 were isolated from liners. No strains isolated in the bodies and environment. Forty five strains isolated were classified as 18 subtypes by phenotyping and genotyping. There was common subtype between A and B herd, but the subtype of C herd showed different pattern. Among predominant subtypes, 60% of S aureus strain isolated from A and B herd showed subtype I and 50% of S aureus strain isolated from C herd belonged to subtype VI and X II. Neither somatic cell count (SCC) nor slime production was significantly different between predominant and minor subtypes. In summary, the study revealed that liners play more important roles in the mode of transmission than environmental sources. Several subtypes can be found in a herd, only a few subtype, however, was largely associated with the majority of infection.

• Journal of Microbiology
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• v.44 no.3
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• pp.293-300
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• 2006

The Escherichia coli heat-labile enterotoxin B subunit (HLT-B) is one of the most powerful mucosal immunogens and known mucosal adjuvants. However, the induction of high levels of HLT-B expression in E. coli has proven a difficult proposition. Therefore, in this study, the HLT-B gene was cloned from pathogenic E. coli and expressed as a fusion protein with GST (glutathion S-transferase) in E. coli BL2l (DE3), in an attempt to harvest a large quantity of soluble HLT-B. The culture conditions, including the culture media used, temperature, pH and the presence of lactose as an inducer, were all optimized in order to obtain an increase in the expression of soluble GST-rHLT-B. The biological activity of the purified rHLT-B was assayed in a series of GMI-ELISA experiments. The findings of these trials indicated that the yield of soluble recombinant GST-rHLT-B could be increased by up to 3-fold, as compared with that seen prior to the optimization, and that lactose was a more efficient alternative inducer than IPTG. The production of rHLT-B, at 92 % purity, reached an optimal level of 96 mg/l in a 3.7 L fermentor. The specific GM1 binding ability of the purified rHLT-B was determined to be almost identical to that of standard CTB.