• Annals of Laboratory Medicine
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• v.38 no.6
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• pp.545-554
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• 2018

Background: The increasing morbidity and mortality rates associated with Acinetobacter baumannii are due to the emergence of drug resistance and the limited treatment options. We compared characteristics of colistin-resistant Acinetobacter baumannii (CR-AB) clinical isolates recovered from patients with and without prior colistin treatment. We assessed whether prior colistin treatment affects the resistance mechanism of CR-AB isolates, mortality rates, and clinical characteristics. Additionally, a proper method for identifying CR-AB was determined. Methods: We collected 36 non-duplicate CR-AB clinical isolates resistant to colistin. Antimicrobial susceptibility testing, Sanger sequencing analysis, molecular typing, lipid A structure analysis, and in vitro synergy testing were performed. Eleven colistin-susceptible AB isolates were used as controls. Results: Despite no differences in clinical characteristics between patients with and without prior colistin treatment, resistance-causing genetic mutations were more frequent in isolates from colistin-treated patients. Distinct mutations were overlooked via the Sanger sequencing method, perhaps because of a masking effect by the colistin-susceptible AB subpopulation of CR-AB isolates lacking genetic mutations. However, modified lipid A analysis revealed colistin resistance peaks, despite the population heterogeneity, and peak levels were significantly different between the groups. Conclusions: Although prior colistin use did not induce clinical or susceptibility differences, we demonstrated that identification of CR-AB by sequencing is insufficient. We propose that population heterogeneity has a masking effect, especially in colistin non-treated patients; therefore, accurate testing methods reflecting physiological alterations of the bacteria, such as phosphoethanolamine-modified lipid A identification by matrix-assisted laser desorption ionization-time of flight, should be employed.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.295-312
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• 2021

BACKGROUND: Global warming is one of the most pressing environmental issues which concomitantly complicates global climate change. Methane emission is a balance between methanogenesis and methane consumption, both of which are driven by microbial actions in different ecosystems producing methane, one of the major greenhouse gases. Paddy fields are major sources of anthropogenic methane emissions and could be compounded by organic fertilization. METHODS AND RESULTS: Literature reviews were conducted to give an overview of the global warming conditions and to present the relationship of carbon and methane to greenhouse gas emissions, and the need to understand the underlying processes of methane emission. A more extensive review was done from studies on methane emission in paddy fields under organic fertilization with greater emphasis on long term amendments. Changes in paddy soils due to organic fertilization include alterations of the physicochemical properties and changes in biological components. There are diverse phylogenetic groups of methanogens and methane oxidizing bacteria involved in methane emission. Also, multiple factors influence methanogenesis and methane oxidation in rice paddy fields under organic fertilization and they should be greatly considered when developing mitigating steps in methane emission in paddy fields especially under long term organic fertilization. CONCLUSION(S): This review showed that organic fertilization, particularly for long term management practices, influenced both physicochemical and biological components of the paddy fields which could ultimately affect methanogenesis, methane oxidation, and methane emission. Understanding interrelated factors affecting methane emission helps create ways to mitigate their impact on global warming and climate change.

• Journal of dental hygiene science
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• v.21 no.3
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• pp.150-157
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• 2021

Background: Stress as a cause of mental health problems is known to be more prevalent in women than in men and has a negative effect on several aspects of physical health, such as the composition of blood and saliva. This study investigated the relationship of perceived stress with blood cell counts, saliva flow rate, and saliva factors. Methods: We recruited women in their 20s with a high prevalence of stress. Stress was evaluated using the Korean version of the perceived stress scale. Blood tests included white blood cell, hemoglobin, and platelet. We then examined the saliva flow rate and cariogenic bacteria level, acidity, occult blood, buffer capacity, leukocyte level, protein level, and ammonia level using rinse water with the SILL-Ha^Ⓡ saliva test system. Results: In a total of 70 participants, the average age was 21.64 years old, the average perceived stress score was 16.96±4.32, and high levels of stress were reported by 80% of the participants (n=56). The high-stress group had lower hemoglobin levels. In addition, the high-stress group showed a lower saliva flow rate than the low-stress group, and there was a difference in the salivary acidity and buffer capacity. The total perceived stress score showed a positive correlation with acidity and negative correlation with buffer capacity and the hemoglobin level. Conclusion: This study found that stress in female college students might affect the composition of blood and saliva. High levels of stress were positively correlated with the hemoglobin level, saliva flow rate, and acidity and negatively correlated with the buffer capacity.

• Journal of Veterinary Science
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• v.22 no.6
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• pp.76.1-76.15
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• 2021

Background: The development of a vaccine for Jembrana disease is needed to prevent losses in Indonesia's Bali cattle industry. A DNA vaccine model (pEGFP-C1-tat) that requires a functional delivery system will be developed. Polylactic-co-glycolic acid (PLGA) may have potential as a delivery system for the vaccine model. Objectives: This study aims to evaluate the in vitro potential of PLGA as a delivery system for pEGFP-C1-tat. Methods: Consensus and codon optimization for the tat gene was completed using a bioinformatic method, and the product was inserted into a pEGFP-C1 vector. Cloning of the pEGFP-C1-tat was successfully performed, and polymerase chain reaction (PCR) and restriction analysis confirmed DNA isolation. PLGA-pEGFP-C1-tat solutions were prepared for encapsulated formulation testing, physicochemical characterization, stability testing with DNase I, and cytotoxicity testing. The PLGA-pEGFP-C1-tat solutions were transfected in HeLa cells, and gene expression was observed by fluorescent microscopy and real-time PCR. Results: The successful acquisition of transformant bacteria was confirmed by PCR. The PLGA:DNA:polyvinyl alcohol ratio formulation with optimal encapsulation was 4%:0.5%:2%, physicochemical characterization of PLGA revealed a polydispersity index value of 0.246, a particle size of 925 nm, and a zeta potential value of -2.31 mV. PLGA succeeded in protecting pEGFP-C1-tat from enzymatic degradation, and the percentage viability from the cytotoxicity test of PLGA-pEGFP-C1-tat was 98.03%. The PLGA-pEGFP-C1-tat demonstrated luminescence of the EGFP-tat fusion protein and mRNA transcription was detected. Conclusions: PLGA has good potential as a delivery system for pEGFP-C1-tat.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.20-26
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• 2019

Background: Ginsenosides, which are bioactive components in ginseng, can be converted to smaller compounds for improvement of their pharmacological activities. The conversion methods include heating; acid, alkali, and enzymatic treatment; and microbial conversion. The aim of this study was to determine the bioconversion of ginsenosides in fermented red ginseng extract (FRGE). Methods: Red ginseng extract (RGE) was fermented using Lactobacillus plantarum KCCM 11613P. This study investigated the ginsenosides and their antioxidant capacity in FRGE using diverse methods. Results: Properties of RGE were changed upon fermentation. Fermentation reduced the pH value, but increased the titratable acidity and viable cell counts of lactic acid bacteria. L. plantarum KCCM 11613P converted ginsenosides $Rb_2$ and $Rb_3$ to ginsenoside Rd in RGE. Fermentation also enhanced the antioxidant effects of RGE. FRGE reduced 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and reducing power; however, it improved the inhibition of ${\beta}$-carotene and linoleic acid oxidation and the lipid peroxidation. This suggested that the fermentation of RGE is effective for producing ginsenoside Rd as precursor of ginsenoside compound K and inhibition of lipid oxidation. Conclusion: This study showed that RGE fermented by L. plantarum KCCM 11613P may contribute to the development of functional food materials.

• Journal of dental hygiene science
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• v.19 no.3
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• pp.162-169
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• 2019

Background: Oral diseases are caused by various systemic and local factors, the most closely related being the biofilm. However, the challenges involved in removing an established biofilm necessitate professional care for its removal. This study aimed to evaluate and compare the effects of professional self and professional biofilm care in healthy patients to prevent the development of periodontal diseases. Methods: Thirty-seven patients who visited the dental clinic between September 2018 and February 2019 were included in this study. Self-biofilm care was performed by routine tooth brushing and professional biofilm care was provided using the toothpick method (TPM) or the oral prophylaxis (OP) method using a rubber cup. Subgingival bacterial motility and halitosis (levels of hydrogen sulfide, $H_2S$; methyl mercaptan, $CH_3SH$; and di-methyl sulfide, $(CH_3)_2S$) were measured before, immediately after, and 5 hours after the preventive treatment in the three groups. Repeated measures analysis of variance test was performed to determine significant differences among the groups. Results: TPM was effective immediately after the prevention treatment, whereas OP was more effective after 5 hours (proximal surfaces, F=16.353, p<0.001; smooth surfaces, F=66.575, p<0.001). The three components responsible for halitosis were effectively reduced by professional biofilm care immediately after the preventive treatment; however, self-biofilm care was more effective after 5 hours ($H_2S$, F=3.564, p=0.011; $CH_3SH$, F=6.657, p<0.001; $(CH_3)_2S$, F=21.135, p<0.001). Conclusion: To prevent oral diseases, it is critical to monitor the biofilm. The dental hygienist should check the oral hygiene status and the ability of the patient to administer oral care. Professional biofilm care should be provided by assessing and treating each surface of the tooth. We hope to strengthen our professional in biofilm care through continuous clinical research.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.185-196
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• 2019

BACKGROUND: This study investigated the effects of rice genetically modified to be resistant against rice blast and rice bacterial blight on the soil microbial community. A comparative analysis of the effects of rice genetically modified rice choline kinase (OsCK1) gene for disease resistance (GM rice) and the Nakdong parental cultivar (non-GM rice) on the soil microbial community at each stage was conducted using rhizosphere soil of the OsCK1 and Nakdong rice. METHODS AND RESULTS: The soil chemistry at each growth stage and the bacterial and fungal population densities were analyzed. Soil DNA was extracted from the samples, and the microbial community structures of the two soils were analyzed by pyrosequencing. No significant differences were observed in the soil chemistry and microbial population density between the two soils. The taxonomic analysis showed that Chloroflexi, Proteobacteria, Firmicutes, Actinobacteria, and Acidobacteria were present in all soils as the major phyla. Although the source tracking analysis per phylogenetic rank revealed that there were differences in the bacteria between the GM and non-GM soil as well as among the cultivation stages, the GM and non-GM soil were grouped according to the growth stages in the UPGMA dendrogram analysis. CONCLUSION: The difference in bacterial distributions between Nakdong and OsCK1 rice soils at each phylogenetic level detected in microbial community analysis by pyrosequencing may be due to the genetic modification done on GM rice or due to heterogeneity of the soil environment. In order to clarify this, it is necessary to analyze changes in root exudates along with the expression of transgene. A more detailed study involving additional multilateral soil analyses is required.

• Journal of Ginseng Research
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• v.43 no.2
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• pp.291-299
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• 2019

Background: Ginsenosides of Korean Red Ginseng extracts (RGE) and its saponin components suppress secretion of inflammasome-mediating cytokines, whereas the nonsaponin fraction (NS) of RGE oppositely stimulates cytokine secretion. Although direct exposure of NS to macrophages in mice induces cytokine production, oral administration of NS has not been studied in inflammasome-related disease in animal models. Methods: Mice were fed RGE or NS for 7 days and then developed peritonitis. Peritoneal cytokines were measured, and peritoneal exudate cells (PECs) were collected to assay expression levels of a set of toll-like receptors (TLRs) and cytokines in response to NS ingestion. In addition, the role of intestinal bacteria in NS-fed mice was assessed. The effect of preexposure to NS in bone marrow-derived macrophages (BMDMs) on cytokine production was further confirmed. Results: NS ingestion attenuated secretion of peritoneal cytokines resulting from peritonitis. In addition, the isolated PECs from NS-fed mice presented lower TLR transcription levels than PECs from control diet-fed mice. BMDMs treated with NS showed downregulation of TLR4 mRNA and protein expression, which was mediated by the $TLR4-MyD88-NF{\kappa}B$ signal pathway. BMDMs pretreated with NS produced less cytokines in response to TLR4 ligands. Conclusion: NS administration directly inhibits TLR4 expression in inflammatory cells such as macrophages, thereby reducing secretion of cytokines during peritonitis.

• Journal of Ginseng Research
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• v.43 no.4
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• pp.692-698
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• 2019

Background: Breast cancer is a severe disease and the second leading cause of cancer death in women worldwide. To surmount this, various diagnosis and treatment options for breast cancer have been developed. One of the most effective strategies for cancer treatment is to induce apoptosis using naturally occurring compounds. Compound K (CK) is a ginseng saponin metabolite generated by human intestinal bacteria. CK has been studied for its cardioprotective, antiinflammatory, and liver-protective effects; however, the role of CK in breast cancer is not fully understood. Methods: To investigate the anticancer effects of CK in SKBR3 and MDA-MB-231 cells, cell viability assays and flow cytometry analysis were used. In addition, the direct targets of CK anticancer activity were identified using immunoblotting analysis and overexpression experiments. Invasion, migration, and clonogenic assays were carried out to determine the effects of CK on cancer metastasis. Results: CK-induced cell apoptosis in SKBR3 cells as determined through 3-(4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assays, propidium iodide (PI) and annexin V staining, and morphological changes. CK increased the cleaved forms of caspase-7, caspase-8, and caspase-9, whereas the expression of Bcl-2 was reduced by CK. In assays probing the cell survival pathway, CK activated only AKT1 and not AKT2. Moreover, CK inhibited breast cancer cell invasion, migration, and colony formation. Through regulation of AKT1 activity, CK exerts anticancer effects by inducing apoptosis. Conclusion: Our results suggest that CK could be used as a therapeutic compound for breast cancer.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.445-454
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• 2020

Background: Culturing wild ginseng adventitious root using plant factory technology provides genetic safety and high productivity. This production technology is drawing attention in the fields of functional raw materials and product development. The cultivation method using elicitors is key technology for controlling biomass and increasing secondary metabolites. Methods and Results: Elicitor treatments using methyl jasmonate, pyruvic acid, squalene, β-sistosterol were performed to amplify total ginsenosides (Rb1, Rc, Rb2, Rb3, and Rd) of cultured wild ginseng adventitious root. Thereafter, fermentation and steaming processes were performed to convert total ginsenosides into minor molecular ginsenosides (Rg3, Rk1, and Rg5). The result indicated that methyl jasmonate minimizes the reduction in fresh weight of cultured wild ginseng adventitious root and maximizes total ginsenosides (sum of Rb1, Rc, Rb2, Rb3, and Rd). Ginsenoside conversion results showed a maximum degree of conversion of 131 mg/g. Conclusions: In this study, we demonstrated that the optimal elicitor treatment method increased the content of total ginsenosides, while the steaming and fermentation processing method increased the content of minor ginsenosides.