• Journal of Microbiology and Biotechnology
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• 제12권3호
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• pp.367-370
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• 2002

A neutral polysaccharide, GP, was isolated from a fermentation broth of Ganoderma lucidum Acid hydrolysis and a paper chromatography analysis indicated that the polysacchride was composed of glucose, xylose, and mannose. The molecular weight was estimated to be $2.9{\times}10^4$. The oral administration of GP to mice showed that it can inhibit liver damage induced by GalN and $CCl_4$.

• Journal of Microbiology and Biotechnology
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• 제27권2호
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• pp.412-415
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• 2017

Prebiotics improve the growth or activities of specific microbial genera and species in the gut microbiota in order to confer health benefits to the host. In this study, we investigated the effect of poly-gamma-glutamate (${\gamma}-PGA$) as a prebiotic on the gut microbiota of mice and the organ distributions of ${\gamma}-PGA$ in mice. Pyrosequencing analysis for 16S rRNA genes of bacteria indicated that oral administration of ${\gamma}-PGA$ increased the abundance of Lactobacillales while reducing the abundance of Clostridiales in murine guts. It is suggested that oral administration of ${\gamma}-PGA$ can be helpful for modulating the gut microbiota as a prebiotic.

• Restorative Dentistry and Endodontics
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• 제44권1호
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• pp.7.1-7.10
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• 2019

Apical periodontitis is a biofilm-mediated infection. The biofilm protects bacteria from host defenses and increase their resistance to intracanal disinfecting protocols. Understanding the virulence of these endodontic microbiota within biofilm is essential for the development of novel therapeutic procedures for intracanal disinfection. Both the disruption of biofilms and the killing of their bacteria are necessary to effectively treat apical periodontitis. Accordingly, a review of endodontic biofilm types, antimicrobial resistance mechanisms, and current and future therapeutic procedures for endodontic biofilm is provided.

• Journal of Microbiology and Biotechnology
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• 제19권12호
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• pp.1569-1572
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• 2009

The pharmacokinetics of decursin and decursinol angelate (D/DA) were investigated in male SD rats following oral and intravenous administration. D/DA and metabolites obtained from in vitro samples were evaluated by LC/MS. The levels of D/DA and metabolized decursinol in the blood following oral and intravenous administrations declined according to first-order kinetics, with $T_{1/2}$ values of 56.67, 58.01, and 57.22 h, respectively, being observed after administration of a dose of 2 mg/kg body weight. The large intestine was the major site of disposition following oral administration. These data indicate that D/DA is rapidly absorbed from the gastrointestinal tract. In in vitro experiment utilizing liver microsomal protein, the major metabolic reaction of D/DA occurred to change decursinol. The cumulative biliary, urinary, and fecal excretions of D/DA in bile duct-cannulated rats was $36.10{\pm}2.9%$, $25.35{\pm}3.8%$, and $34.20{\pm}3.2%$, respectively, at 72 h after administration. These results indicate that the absorption of D/DA is almost complete, and that its metabolites are primarily excreted into feces through the bile. These results indicate that D/DA is subject to enterohepatic circulation.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.964-967
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• 2008

Two structural protein genes, VP19 and VP466, of white spot syndrome virus (WSSV) were cloned and expressed in Sf21 insect cells using a baculovirus expression system for the development of injection and oral feeding vaccines against WSSV for shrimps. The cumulative mortalities of the shrimps vaccinated by the injection of rVP19 and rVP466 at 15 days after the challenge with WSSV were 50.2% and 51.8%, respectively. For the vaccination by oral feeding of rVP19 and rVP466, the cumulative mortalities were 49.2% and 89.2%, respectively. These results show that protection against WSSV can be generated in the shrimp, using the viral structural protein as a protein vaccine.

• IMMUNE NETWORK
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• 제22권4호
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• pp.32.1-32.20
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• 2022

Sjögren syndrome (SS) is a chronic autoimmune disorder that primarily targets the salivary and lacrimal glands. The pathology of these exocrine glands is characterized by periductal focal lymphocytic infiltrates, and both T cell-mediated tissue injury and autoantibodies that interfere with the secretion process underlie glandular hypofunction. In addition to these adaptive mechanisms, multiple innate immune pathways are dysregulated, particularly in the salivary gland epithelium. Our understanding of the pathogenetic mechanisms of SS has substantially improved during the past decade. In contrast to viral infection, bacterial infection has never been considered in the pathogenesis of SS. In this review, oral dysbiosis associated with SS and evidence for bacterial infection of the salivary glands in SS were reviewed. In addition, the potential contributions of bacterial infection to innate activation of ductal epithelial cells, plasmacytoid dendritic cells, and B cells and to the breach of tolerance via bystander activation of autoreactive T cells and molecular mimicry were discussed. The added roles of bacteria may extend our understanding of the pathogenetic mechanisms and therapeutic approaches for this autoimmune exocrinopathy.

• International Journal of Oral Biology
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• 제37권2호
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• pp.69-75
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• 2012

Although neutrophils function in both defense and tissue destruction, their defensive roles have rarely been studied in association with periodontitis. We hypothesized that peripheral neutrophils are pre-activated in vivo in periodontitis and that hyperactive neutrophils would show enhanced phagocytic ability as well as an increased production of reactive oxygen species (ROS). Peripheral blood neutrophils from patients with aggressive periodontitis and age/gender-matched healthy subjects (10 pairs) were isolated. The levels of CD11b and CD64 expression on the neutrophils and the level of plasma endotoxin were determined by flow cytometry and a limulus amebocyte lysate test, respectively. In addition, neutrophils were subjected to a flow cytometric phagocytosis assay and luminol-enhanced chemiluminescence for non-opsonized Fusobacterium nucleatum in parallel. The neutrophilsfrom most patients expressed increased levels of both CD11b and CD64. In addition, the plasma from these patients tended to contain a higher level of endotoxin than the healthy controls. In contrast, no differences were found between the two groups with regard to phagocytosis or ROS generation by F. nucleatum. The ability to phagocytose F. nucleatum was found to positively correlate with the ability to produce ROS. In conclusion, peripheral neutrophils from patients with aggressive periodontitis are hyperactive but not hyperreactive to F. nucleatum.

• 대한미생물학회지
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• 제35권1호
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• pp.77-85
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• 2000

Streptococcus mutans is the most important causative bacteria of dental caries among the oral bacteria. Lactococcus lactis 1370 was isolated from the oral cavity of child. The effect of Lactococcus lactis 1370 on the formation of artificial plaque by Streptococcus mutans was studied. 1. The insoluble substances and bacteria were much more attached on the wall of disposable cuvette in the culture of Streptococcus mutans than in the combined culture of Streptococcus mutans and Lactococcus lactis 1370. 2. The mean weight of produced artificial plaque on the wires in the beaker was 131.7 mg in the culture of Streptococcus mutans only, whereas being reduced to 6.4 mg in the combined culture of Streptococcus mutans and Lactococcus lactis 1370 (p<0.05). The viable cell didn't show the significant difference between them after culturing. 3. When Streptococcus mutans was cultured in the media containing culture supernatant of Lactococcus lactis 1370 cultured in M17 broth containing 0.5% yeast extract and 5% sucrose, the mean weight of produced artificial plaque was 8.0 mg on the wires, whereas being 125.4 mg in the media without culture supernatant of Lactococcus lactis 1370 (p<0.05). The viable cell didn't show the significant difference between them after culturing. 4. When Streptococcus mutans was cultured in the media containing soluble polymer produced by Lactococcus lactis 1370, the mean weight of produced artificial plaque was significantly reduced compared with being cultured in the media without soluble polymer (p<0.05). The viable cell didn't show the significant difference between them after culturing. 5. The soluble polymer produced by Lactococcus lactis 1370 was glucan. 6. The glucan produced by Lactococcus lactis 1370 was water-soluble glucan containing ${\alpha}$-1,6-glucose linkage as the main linkage. These results suggest that the artificial plaque formed by Streptococcus mutans is inhibited by water-soluble glucan produced by Lactococcus lactis 1370.

• Journal of Microbiology and Biotechnology
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• 제31권10호
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• pp.1383-1392
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• 2021

Carbapenem-resistant Enterobacteriaceae (CRE) that produce Klebsiella pneumoniae carbapenemase are increasingly reported worldwide and have become more and more resistant to nearly all antibiotics during the past decade. The emergence of K. pneumoniae strains with decreased susceptibility to carbapenems, which are used as a last resort treatment option, is a significant threat to hospitalized patients worldwide as K. pneumoniae infection is responsible for a high mortality rate in the elderly and immunodeficient individuals. This study used Lactobacillus fermentum as a candidate probiotic for treating CRE-related infections and investigated its effectiveness. We treated mice with L. fermentum originating from the vaginal fluid of a healthy Korean woman and evaluated the Lactobacilli's efficacy in preventive, treatment, nonestablishment, and colonization mouse model experiments. Compared to the control, pre-treatment with L. fermentum significantly reduced body weight loss in the mouse models, and all mice survived until the end of the study. The oral administration of L. fermentum after carbapenem-resistant Klebsiella (CRK) infection decreased mortality and illness severity during a 2-week observation period and showed that it affects other strains of CRK bacteria. Also, the number of Klebsiella bacteria was decreased to below 5.5 log₁₀ CFU/ml following oral administration of L. fermentum in the colonization model. These findings demonstrate L. fermentum's antibacterial activity and its potential to treat CRE infection in the future.

• 대한소아치과학회지
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• 제30권1호
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• pp.61-68
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• 2003

치아우식증을 예방하기 위한 백신연구를 위하여 주원인균인 Sterptococcus mutans 균체항원과 이 균에서 분리한 glucosyltransferase (GTF)를 항원으로 하고 이에 면역조절기능이 있는 retinoic acid (RA)를 첨가하여 투여경로와 백신조성이 이들 항원에 대한 면역반응에 미치는 영향을 실험하였다. 균체항원(Ingbritt strain)을 마우스의 피하에 Complete Freund's Adjuvant와 함께 투여하여 생산되는 혈청내 응집항체가는 serotype e (LM-7)와는 강한 교차반응을 보였으나 serotype f (OMZ-175)와는 거의 교차반응을 일으키지 않았다. 면역혈청내 항-GTF 및 항-Ag I/II 항체중 항-GTF IgA는 피하로 투여시 전혀 검출되지 않았으나 이에 RA를 첨가하면 다량의 항체 생산을 관찰하였고 그 정도는 경구투여시의 생산량을 능가하였다. GTF를 alum과 함께 투여하여 생산되는 혈청내 항-GTF 항체중 IgM은 피하로 투여시 상당량이 검출되었고 RA를 첨가하면 그 생산이 증가되었으며 경구로 투여시 대조군에 비하여 약간증가를 보였으나 피하투여시의 그것에는 미치지 못하였다. GTF-특이 IgG는 경구투여시는 전혀 검출되지 아니하였고, 피하투여시에만 현저한 증가를 보였으며, RA첨가는 이에 영향을 미치지 못하였다. 항-GTF IgA는 피하로 투여시 전혀 검출되지 아니하였으나 이에 RA를 첨가하면 증가된 항체생산을 관찰하였고 그 정도는 경구투여시의 생산량을 능가하였다. 이상의 실험성적은 GTF에 대한 항체생산은 투여경로와 항원의 종류에 따라 다양한 반응을 나타내며 RA는 이를 백신에 첨가하면 피하경로를 이용하여 면역하더라도 경구투여와 유사한 IgA-매개 면역반응으로 조절시킬 수 있는 가능성을 나타내었다.