• Biomedical Science Letters
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• v.25 no.4
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• pp.431-435
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• 2019

Chlorine dioxide is an effective chemical to inhibit the growth of bacteria and viruses or to disinfect infected areas. In this study, the effects of chlorine dioxide on several bacteria in hospitals were analyzed. Alloiococcus otitis, Kocuria rosea, Leuconostoc mesenteroides spp. and Staphylococcus lentus as gram-positive bacteria and Acinetobacter lwoffii, Aeromonas salmonicida, Brucella melitensis, Oligella ureolytica as gram-negative bacteria were done for the inhibitory analysis. The growth and morphology of the bacteria were analyzed by placing a plastic stick which was called "FarmeTok (medistick/Puristic)" provided by Purgofarm, co, Ltd. to release ClO₂ (13 ppmv/hr) next to the plate where the bacteria were incubated for 24 hours. Less than 10 bacterial colonies were evaluated as having 99% inhibitory effect. The initial bacterial culture concentration of 0.5 McFaland turbidity was good for analyzing the chlorine dioxide inhibitory effect. All bacteria could be easily counted post 24 hr co-incubation with ClO₂, but A. otitis and A. lwoffii without ClO₂ gas were not countable due to very dispersed colony types which were not affected for result analysis. As shown in this study, the FarmeTok plastic stick, which discharges chlorine dioxide at 13 ppmv / hour, was evaluated to be sufficient to suppress the above bacteria in the hospital. Bacteria existing in the clinic such as this hospital will be used as a data to inhibit the growth of bacteria by using ClO₂, and molecular biology analysis using the gene of bacteria will be possible in the future rather than inhibiting the growth of bacteria itself.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.98-98
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• 1993

To cause invasive disease, microorganism must attach firmly to the tonsillar epithelial cell. Once attached, the microorganisms can proliferated, form colonies and release extracillular toxins which can injure the underlying cells. The purpose of present study was to asertain whether or not there exist in vivo differences in bacterial attachment between patients with acute tonsillitis and healthy individuals as a control. This study was carried out on 20 patients suffering from acute tonsillitis and 20 healthy persons used as control. After scraping of the surface of tonsil, cellular mixture was stained with Acridine orange and the number of attached bacteria was calculated using a fluorescent microscope. The adherence rate was calculated as number of bacteria attached to each of 50 epithelial cells. simultaneously, we peformed conventional bacterial culture. Conclusively, the attachment of more than 10% bacteria to the tonsillar epithelial cell was significantly greater in acute tonsillitis group than control group, and there was a significant correlation between age and the number of the attached bacteria to the epithlium.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.75-85
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• 2021

Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on "trigger" entry mechanism and intracellular survival S. Typhimurium. Conclusion: Rg3 could be considered as a supplement agent to prevent S. Typhimurium infection.

• Clinical and Experimental Vaccine Research
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• v.12 no.1
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• pp.70-76
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• 2023

Purpose: Typhoid remains a major health problem, especially in the developing world. Furthermore, the emergence of multidrug-resistant and extensively drug-resistant strains of Salmonella typhi added a sense of urgency to develop more effective typhoid vaccines, one of which is bacterial ghosts (BGs), prepared by both genetic and chemical means. The chemical method includes incubation with numerous agents for a short time at their minimum inhibitory or minimum growth concentrations. This study included the preparation of BGs by a sponge-like reduced protocol (SLRP). Materials and Methods: Critical concentrations of sodium dodecyl sulfate, NaOH, and H₂O₂ were used. Moreover, high-quality BGs were visualized by scanning electron microscope (SEM). Subculturing was used to confirm the absence of vital cells. Besides, the concentrations of the released DNA and protein were estimated spectrophotometrically. In addition, the integrity of cells was proved by visualizing Gram-stained cells using a light microscope. Furthermore, a comparison between the immunogenicity and safety of the prepared vaccine and the available whole-cell killed vaccine was established. Results: Improved preparation of high-quality BGs of S. typhi, visualized by SEM, revealed punctured cells with intact outer shells. Moreover, the absence of vital cells was confirmed by subculturing. At the same time, the release of respective amounts of proteins and DNA is another evidence of BGs' production. Additionally, the challenge test provided evidence that the prepared BGs are immunogenic and have the same efficacy as the whole cell vaccine. Conclusion: The SLRP provided a simple, economical, and feasible method for BGs preparation.

• Animal Bioscience
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• v.36 no.2
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• pp.315-321
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• 2023

Objective: The study was conducted to investigate the dephosphorylation of Pseudomonas aeruginosa flagellin (PA FLA) by sweet potato purple acid phosphatase (PAP) and the effect of the enzyme on the flagellin-mediated inflammatory response in the A549 lung epithelial cell line. Methods: The activity of sweet potato PAP on PA FLA was assayed at different pH (4, 5.5, 7, and 7.5) and temperature (25℃, 37℃, and 55℃) conditions. The release of interleukin-8 (IL-8) and the activation of nuclear factor kappa- light-chain-enhancer of activated B cells (NF-κB) in A549 cells exposed to PA FLA treated with or without sweet potato PAP was measured using IL-8 and NF-κB ELISA kits, respectively. The activation of toll-like receptor 5 (TLR5) in TLR5-overexpressing HEK-293 cells exposed to PA FLA treated with or without sweet potato PAP was determined by the secreted alkaline phosphatase-based assay. Results: The dephosphorylation of PA FLA by sweet potato PAP was favorable at pH 4 and 5.5 and highest at 55℃. PA-FLA treated with the enzyme decreased IL-8 release from A549 cells to about 3.5-fold compared to intact PA FLA at 1,000 ng/mL of substrate. Moreover, PA-FLA dephosphorylated by the enzyme repressed the activation of NF-κB in the cells compared to intact PA FLA. The activation of TLR5 by PA-FLA was highest in TLR-overexpressing HEK293 cells at a substrate concentration of 5,000 ng/mL, whereas PA FLA treated with the enzyme strongly repressed the activation of TLR5. Conclusion: Sweet potato PAP has the potential to be a new alternative agent against the increased antibiotic resistance of P. aeruginosa and may be a new conceptual feed additive to control unwanted inflammatory responses caused by bacterial infections in animal husbandry.

• Animal Bioscience
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• v.35 no.6
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• pp.892-901
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• 2022

Objective: This study was performed to investigate the potential effect of wheat phytase on long-chain inorganic polyphosphate (polyP)-mediated interleukin 8 (IL-8) signaling in an intestinal epithelial cell line, HT-29 cells. Methods: Cell viability and the release of the pro-inflammatory cytokine IL-8 in HT-29 cells exposed to polyP1150 (average of 1,150 phosphate residues) treated with or without wheat phytase were measured by the EZ-CYTOX kit and the IL-8 ELISA kit, respectively. Also, the activation of cellular inflammatory factors NF-κB and MAPK (p38 and ERK 1/2) in HT-29 cells was investigated using ELISA kits. Results: PolyP1150 negatively affected the viability of HT-29 cells in a dose-dependent manner. However, 100 mM polyP1150 dephosphorylated by wheat phytase increased cell viability by 1.4-fold over that of the intact substrate. Moreover, the 24 h exposure of cells to enzyme-treated 50 mM polyP1150 reduced the secretion of IL-8 and the activation of NF-κB by 9% and 19%, respectively, compared to the intact substrate. PolyP1150 (25 and 50 mM) dephosphorylated by the enzyme induced the activation of p38 MAPK via phosphorylation to 2.3 and 1.4-fold, respectively, compared to intact substrate, even though it had little effect on the expression of ERK 1/2 via phosphorylation. Conclusion: Wheat phytase could attenuate polyP1150-induced IL-8 release in HT-29 cells through NF-κB, independent of MAP kinases p38 and ERK. Thus, wheat phytase may alleviate inflammatory responses including hypercytokinemia caused by bacterial polyP infection in animals. Therefore, wheat phytase has the potential as an anti-inflammatory therapeutic supplement in animal husbandry.

• Nutrition Research and Practice
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• v.17 no.1
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• pp.164-173
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• 2023

BACKGROUND/OBJECTIVES: Hyperglycemia is a major cause of diabetes and diabetesrelated diseases. Sodium butyrate (NaB) is a short-chain fatty acid derivative that produces dietary fiber by anaerobic bacterial fermentation in the large intestine and occurs in foods, such as Parmesan cheese and butter. Butyrate has been shown to prevent obesity, improve insulin sensitivity, and ameliorate dyslipidemia in diet-induced obese mice. Therefore, this study examined the effects and mechanism of NaB on the secretion of inflammatory cytokines induced by high glucose (HG) in THP-1 cells. MATERIALS/METHODS: THP-1 cells were used as an in vitro model for HG-induced inflammation. The cells were cultured under normal glycemic or hyperglycemic conditions with or without NaB (0-25 μM). Western blotting and quantitative polymerase chain reaction were used to evaluate the protein and mRNA levels of nuclear factor-κB (NF-κB), interleukin-6, tumor necrosis factor-α, acetylated p65, acetyl CREB-binding protein/p300 (CBP/p300), and p300 using THP-1 cells. Histone acetyltransferase (HAT), histone deacetylase (HDAC), and pro-inflammatory cytokine secretion activity were analyzed using an enzyme-linked immunosorbent assay. RESULTS: HG significantly upregulated histone acetylation, acetylation levels of p300, NF-κB activation, and inflammatory cytokine release in THP-1 cells. Conversely, the NaB treatment reduced cytokine release and NF-κB activation in HG-treated cells. It also significantly reduced p65 acetylation, CBP/p300 HAT activity, and CBP/p300 gene expression. In addition, NaB decreased the interaction of p300 in acetylated NF-κB and TNF-α. CONCLUSIONS: These results suggest that NaB suppresses HG-induced inflammatory cytokine production through HAT/HDAC regulation in monocytes. NaB has the potential for preventing and treating diabetes and its related complications.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.365-374
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• 2016

In high-latitude regions, temperature has risen ($0.6^{\circ}C$ per decade) and this leads to the increase in microbial degradability against soil organic carbon (SOC). Furthermore, the decomposed SOC is converted into green-house gases ($CO_2$ and $CH_4$) and their release could further increase the rate of climate change. Thus, understanding the microbial diversity and their functions linked with SOC degradation in soil-thawing model is necessary. In this study, we divided tundra soil from Council, Alaska into two depth regions (30-40 cm and 50-60 cm of depth, designated as SPF and PF, respectively) and incubated that for 108 days at $0^{\circ}C$. A total of 111,804 reads were obtained through a pyrosequencing-based metagenomic study during the microcosm experiments, and 574-1,128 of bacterial operational taxonomic units (OTUs) and 30-57 of archaeal OTUs were observed. Taxonomic analysis showed that the distribution of bacterial taxa was significantly different between two samples. In detail, the relative abundance of phyla Actinobacteria and Firmicutes largely increased in SPF and PF soil, respectively, while phyla Crenarchaeota was increased in both soil samples. Weight measurement and gel permeation chromatography of the SOC extracts demonstrated that polymerization of humic acids, main component of SOC, occurred during the microcosm experiments. Taken together our results indicate that these bacterial and archaeal phyla could play a key function in SOC degradation and utilization in cold tundra soil.

• Tuberculosis and Respiratory Diseases
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• v.70 no.2
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• pp.125-131
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• 2011

Background: The clinical manifestation of $M.$ $tuberculosis$ infection ranges from asymptomatic latent infection, to focal forms with minimal symptoms and low bacterial burdens, and finally to advanced tuberculosis (TB) with severe symptoms and high bacillary loads. We investigated the diagnostic sensitivity of the whole-blood interferon-${\gamma}$ release assay according to the wide spectrum of clinical phenotypes. Methods: In patients diagnosed with active TB that underwent $QuantiFERON^{(R)}$ (QFT) testing, the QFT results were compared with patients known to be infected with pulmonary tuberculosis (P-TB) and extra-pulmonary TB (EP-TB). In addition, the results of the QFT test were further analyzed according to the radiographic extent of disease in patients with P-TB and the location of disease in patients with EP-TB. Results: There were no statistical differences in the overall distribution of QFT results between 177 patients with P-TB and 84 patients with EP-TB; the positive results of QFT test in patients with P-TB and EP-TB were 70.1% and 64.3%, respectively. Among patients with P-TB, patients with mild extents of disease showed higher frequency of positive results of QFT test than that of patients with severe form (75.2% vs. 57.1%, respectively; p=0.043) mainly due to an increase of indeterminate results in severe P-TB. Patients with TB pleurisy showed lower sensitivity by the QFT test than those with tuberculous lymphadenitis (48.8% vs. 78.8%, respectively; p=0.019). Conclusion: Although QFT test showed similar results between overall patients with P-TB and EP-TB, individual sensitivity was different according to the radiographic extent of disease in P-TB and the location of disease in EP-TB.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.994-1001
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• 2001

An easier way of understanding the BNR system was proposed from the study on substrate, nutrient removal tendency, microbial community and its metabolic function by applying the municipal settled sewage. During the anaerobic period, the phosphorus release rate per VFACOD we varied depending on the phosphorus content in the sludge. When the phosphorus content in the sludge was $6\%$ VSS, according to influent VFACOD, the phosphorus release rate and PHA production were $0.35 gPO_4P/gVFACOD$ and 1.0 gPHA/gVFACOD, respectively. The $NO_3N$ requirement for the phosphorus uptake as an electron acceptor was about $0.5 gNO_3N/gPO_4P_{uptake}$ based on the proposed equation with PHA, biomass, production, and the concentration of phosphorus release/uptake. Bacterial-community analysis of the sludge, as determined by FISH and 16SrDNA characterization FISH, revealed that the beta-subclass proteobacteria were the most abundant group ($27.9\%$ of the proteobacteria-specific probe EUB338), and it was likely that representative of the beta-subclass played key roles in activated sludge. The next dominant group found was the gamma-protebacteria ($15.4\%$ of probe EUB338). 16S rDNA clone library analysis showed that the members of${\beta}$- and ${\gamma}$-proteobacteria were also the most abundant groups, and $21.5\%$ (PN2 and PN4) and $15.4\%$ (PN1 and PN5) of total clones were the genera of denitrifying bacteria and PAO, respectively. Prediction of the microbial community composition was made with phosphorus content (Pv, $\%$ P/VSS) in wasted sludge and profiles of COD, PHA, $PO_4P,\;and\;NO_3N$ in an anaerobic-anoxic SBR unit. Generally, the predicted microbial composition based upon metabolic function, i.e., as measured by stoichiometry, is fairly similar to that measure by the unculturable dependent method. In this study, a proposal was made on he microbial community composition that was more easily approached to analyze the reactor behavior.