• Journal of Microbiology and Biotechnology
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• v.27 no.9
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• pp.1711-1715
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• 2017

In this study, we characterized the $bla_{NDM-5}$-bearing plasmid in a Klebsiella pneumoniae isolate that had lost the plasmid during serial passage. We determined the complete sequences of the plasmid pCC1410-2, which was extracted from a K. pneumoniae ST709 isolate collected at a Korean hospital from which two NDM-5-producing K. pneumoniae isolates were subsequently isolated. As a result, the pCC1410-2 plasmid had a backbone structure that was similar to those of two plasmids previously reported from the same hospital, but lacked some antibiotic resistance genes ($bla_{TEM-1}$, rmtB, mphR(A), mrx(A), and mph(A)). A 9-bp repeating unit encoding three amino acids (Gln-Gln-Pro) was inserted in TraD in pCC1410-2. Thus, the pCC1410-2 plasmid might be transferred from the previously identified carbapenem-resistant K. pneumoniae, but some delections and inversions might have occurred during the process. We compared the transfer frequency and stability of the plasmids. The relative frequency of conjugative transfer and stability in the host were significantly lower in pCC1410-2 than in previously reported $bla_{NDM-5}$-bearing plasmids in Korea. A low transfer frequency and instability in the host may cause underestimation of carbapenemase-producing Enterobacteriaceae in the clinical setting and in surveillance studies.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.579-590
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• 2020

Botrytis cinerea, which causes gray mold disease in more than 200 plant species, is an economically important pathogen that is mainly controlled by synthetic fungicides. Synergistic fungicide mixtures can help reduce fungicide residues in the environment and mitigate the development of fungicide-resistant strains. In this study, we screened microbial culture extracts on Botrytis cinerea to identify an antifungal synergist for tebuconazole. Among the 4,006 microbial extracts screened in this study, the culture extract from Schizophyllum commune displayed the most enhanced activity with a sub-lethal dosage of tebuconazole, and the active ingredient was identified as schizostatin. In combination with 5 ㎍/ml tebuconazole, schizostatin (1 ㎍/ml) showed disease control efficacy against gray mold on tomato leaf similar to that achieved with 20 ㎍/ml tebuconazole treatment alone. Interestingly, schizostatin showed demethylation inhibitor (DMI)-specific synergistic interactions in the crossed-paper strip assay using commercial fungicides. In a checkerboard assay with schizostatin and DMIs, the fractional inhibitory concentration values were 0.0938-0.375. To assess the molecular mechanisms underlying this synergism, the transcription levels of the ergosterol biosynthetic genes were observed in response to DMIs, schizostatin, and their mixtures. Treatment with DMIs increased the erg11 (the target gene of DMI fungicides) expression level 15.4-56.6-fold. However, treatment with a mixture of schizostatin and DMIs evidently reverted erg11 transcription levels to the pre-DMI treatment levels. These results show the potential of schizostatin as a natural antifungal synergist that can reduce the dose of DMIs applied in the field without compromising the disease control efficacy of the fungicides.

• Korean Journal of Microbiology
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• v.54 no.1
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• pp.84-86
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• 2018

Cells of Deinococcus puniceus $DY1^T$ are Gram-positive, coccus-shaped, and crimson color-pigmented. Strain $DY1^T$ was isolated from soil irradiated with 5 kGy gamma radiation and showed resistance to UVC and gamma radiation. In this study, we report the complete genome sequence of a bacterium Deinococcus puniceus $DY1^T$ is consist of circular chromosome comprised of 2,971,983 bp, with the G + C content of 62.5%. The complete genome sequence was obtained using the PacBio RS II platform, it included 2,617 coding sequences (CDs), 2,762 genes, and 88 pseudogene.

• Journal of Physiology & Pathology in Korean Medicine
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• v.29 no.1
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• pp.51-57
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• 2015

Bone destruction is a pathological symptom of some chronic inflammatory diseases, such as rheumatoid arthritis and periodontitis. Inflammation-induced bone loss of these diseases results from increased number and activity of osteoclasts. Paeoniae Radix Alba has been used in korean traditional medicine to treat disease including inflammation, gynecopathy and various pain. However, these effects have not been tested on osteoclasts, the bone resorbing cells that regulate bone metabolism. Here, we investigated the effects of Paeoniae Radix Alba ethanol extract (PRAE) on receptor activator of nuclear factor-kappa B ligand (RANKL)-mediated osteoclast differentiation and formation. Osteoclast differentiation and formation were measured by tartrate resistant acidic phosphatase (TRAP) staining and TRAP solution assay. The treatment of PRAE on bone marrow derived macrophages (BMMs), which is known as osteoclast precursor cells, inhibited osteoclast differentiation and formation in a dose-dependent manner. In addition, the expression of osteoclast differentiation marker genes was suppressed by PRAE treatment. This inhibitory effect of PRAE resulted from significant repression of c-Fos expression, and subsequent reduction of NFATc1 expression which was previously reported as a master transcription factor for osteoclastogenesis in vitro and in vivo. These results demonstrate that PRAE negatively regulates osteoclast differentiation and formation and suggest that PRAE can be used as a potent preventive or therapeutic candidate for various bone diseases, such as postmenopausal osteoporosis, periodontitis and rheumatoid arthritis.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.227-232
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• 2015

Genetic polymorphisms of pvdhfr and pvdhps genes of Plasmodium vivax were investigated in 83 blood samples collected from patients in the Philippines, Bangladesh, and Nepal. The SNP-haplotypes of the pvdhfr gene at the amino acid positions 13, 33, 57, 58, 61, 117, and 173, and that of the pvdhps gene at the positions 383 and 553 were analyzed by nested PCR-RFLP. Results suggest diverse polymorphic patterns of pvdhfr alone as well as the combination patterns with pvdhps mutant alleles in P. vivax isolates collected from the 3 endemic countries in Asia. All samples carried mutant combination alleles of pvdhfr and pvdhps. The most prevalent combination alleles found in samples from the Philippines and Bangladesh were triple mutant pvdhfr combined with single mutant pvdhps allele and triple mutant pvdhfr combined with double wild-type pvdhps alleles, respectively. Those collected from Nepal were quadruple mutant pvdhfr combined with double wild-type pvdhps alleles. New alternative antifolate drugs which are effective against sulfadoxine-pyrimethamine (SP)-resistant P. vivax are required.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.631-636
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• 2016

This study aimed to develop a multiplex-touchdown PCR method to simultaneously detect 3 species of protozoan parasites, i.e., Cryptosporidium parvum, Giardia lamblia, and Cyclospora cayetanensis, the major causes of traveler's diarrhea and are resistant to standard antimicrobial treatments. The target genes included the Cryptosporidium oocyst wall protein for C. parvum, Glutamate dehydrogenase for G. lamblia, and 18S ribosomal RNA (18S rRNA) for C. cayetanensis. The sizes of the amplified fragments were 555, 188, and 400 bps, respectively. The multiplex-touchdown PCR protocol using a primer mixture simultaneously detected protozoa in human stools, and the amplified gene was detected in > $1{\times}10^3$ oocysts for C. parvum, > $1{\times}10^4$ cysts for G. lamblia, and > 1 copy of the 18S rRNA gene for C. cayetanensis. Taken together, our protocol convincingly demonstrated the ability to simultaneously detect C. parvum, G. lamblia, and C. cayetanenesis in stool samples.

• The Plant Pathology Journal
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• v.35 no.4
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• pp.321-329
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• 2019

Ascochyta blight caused by Ascochyta rabiei (Pass.) Lab. (Telomorph: Didymella rabiei) (Kov.) is one of the most important fungal diseases in chickpea worldwide. Knowledge about pathogen aggressiveness and identification resistance sources to different pathotypes is very useful for proper decisions in breeding programs. In this study, virulence of 32 A. rabiei isolates from different part of Iran were analyzed on seven chickpea differentials and grouped into six races based on 0-9 rating scale and susceptibility/resistant pattern of chickpea differentials. The least and most frequent races were race V and race I, respectively. Race V and VI showed highly virulence on most of differential, while race I showed least aggressiveness. Resistance pattern of 165 chickpea genotypes also were tested against six different A. rabiei races. ANOVA analysis showed high significant difference for isolate, chickpea genotypes and their interactions. Overall $chickpea{\times}isolate$ (race) interactions, 259 resistance responses (disease severity ${\leq}4$) were identified. Resistance spectra of chickpea genotypes showed more resistance rate to race I (49.70%) and race III (35.15%), while there were no resistance genotypes to race VI. Cluster analysis based on disease severity rate, grouped chickpea genotypes into four distinct clusters. Interactions between isolates or races used in this study, showed the lack of a genotype with complete resistance. Our finding for virulence pattern of A. rabiei and newly identified resistance sources could be considerably important for integration of ascochyta blight resistance genes into chickpea breeding programs and proper decision in future for germplasm conservation and diseases management.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1401-1411
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• 2019

Mycobacterial cell walls comprise thick and diverse lipids and glycolipids that act as a permeability barrier to antibiotics or other chemical agents. The use of OH radicals from a non-thermal plasma jet (NTPJ) for the inactivation of mycobacteria in aqueous solution was adopted as a novel approach. Addition of water vapor in a nitrogen plasma jet generated OH radicals, which converted to hydrogen peroxide ($H_2O_2$) that inactivated non-pathogenic Mycobacterium smegmatis and pathogenic Mycobacterium tuberculosis H37Rv. A stable plasma plume was obtained from a nitrogen plasma jet with 1.91 W of power, killing Escherichia coli and mycobacteria effectively, whereas addition of catalase decreased the effects of the former. Mycobacteria were more resistant than E. coli to NTPJ treatment. Plasma treatment enhanced intracellular ROS production and upregulation of genes related to ROS stress responses (thiolrelated oxidoreductases, such as SseA and DoxX, and ferric uptake regulator furA). Morphological changes of M. smegmatis and M. tuberculosis H37Rv were observed after 5 min treatment with $N_2+H_2O$ plasma, but not of pre-incubated sample with catalase. This finding indicates that the bactericidal efficacy of NTPJ is related to the toxicity of OH and $H_2O_2$ radicals in cells. Therefore, our study suggests that NTPJ treatment may effectively control pulmonary infections caused by M. tuberculosis and nontuberculous mycobacteria (NTM) such as M. avium or M. abscessus in water.

• Biomedical Science Letters
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• v.26 no.4
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• pp.288-295
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• 2020

Infection of Helicobacter pylori on gastric mucosa is associated with various gastric diseases. According to the WHO, H. pylori causes gastric cancer and has been classified as a class I carcinogen. Riboflavin is an essential vitamin which presents in a wide variety of foods. Previous studies have shown that riboflavin/UVA was effective against the growth inhibition of Staphylococcus aureus, S. epidermidis and multidrug-resistant Pseudomonas aeruginosa and had the potential for antimicrobial properties. Thus, we hypothesized that riboflavin has a potential role in the growth inhibition of H. pylori. To demonstrate inhibitory concentration of riboflavin against H. pylori, we performed agar and broth dilution methods. As a result, we found that riboflavin inhibited the growth of H. pylori. The MIC was 1 mM in agar and broth dilution test. Furthermore, to explain the inhibitory mechanism, we investigated whether riboflavin has an influence on the replication-associated molecules of the bacteria using RT-PCR to detect mRNA expression level in H. pylori. Riboflavin treatment of H. pylori led to down-regulation of polA and dnaB mRNA expression levels in a dose dependent manner. After then, we also confirmed whether riboflavin has cytotoxicity to human cells. We used AGS, a gastric cancer cell line, and treated with riboflavin did not show statistically significant decrease of cell viability. Thus, these results indicate that riboflavin can suppress the replication machinery of H. pylori. Taken together, these findings demonstrate that riboflavin inhibits growth of H. pylori by inhibiting replication of the bacteria.

• The Journal of Internal Korean Medicine
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• v.43 no.4
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• pp.606-624
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• 2022

Objective: The aim of this study was to compare the effects of different doses of Geumnyeonyijin-tang (GNYJT) water extracts with those of metformin (250 mg/kg) in mild diabetic-obese mice. Methods and Results: The 48 mice were divided into 1 normal pellet diet (NFD) group and 5 high-fat diet (HFD) groups. At the end of 12 weeks of oral administration of metformin (250 mg/kg) or GNYJT water extracts (400, 200, or100 mg/kg), the effects were evaluated. The HFD control mice showed noticeable increases in body weight, adipose tissue density, fat pad weight of the periovarian and abdominal wall, and insulin, blood glucose, and HbA1c levels, with decreases in serum HDL levels. Increases in the periovarian and dorsal abdominal fat pad, regions of steatohepatitis, adipocyte hypertrophy, and hepatocyte hypertrophy were also discovered. The HFD group showed a decline in glucose levels and elevation of hepatic gluconeogenesis, suggesting an HFD-induced AMPK downregulation related to glucose dysregulation, as well as lipid metabolism related to obese insulin-resistant type II diabetes, dyslipidemia, and oxidative stress related diabetic hepatopathy (non-alcoholic fatty liver disease, NAFLD). Conclusion: Assessment of the key parameters for inhibition of diabetes and related complications in HFD-fed diabetic-obese mice demonstrated that GNYJT water extracts have favorable ameliorating effects. The effect of GNYJT was manifested through the stimulation of AMPK upregulation of related hepatic glucose enzyme activities and expression of lipid metabolism-related genes. Therefore, appropriate oral dosages of GNYJT could be promising as a new preventive candidate for controlling diabetes and related complications. Further screening of biologically active compounds, elucidation of detailed mechanisms, and more animal studies are warranted.