Jeonju, South Korea
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Kim S.,Chungnam National University | Sung J.Y.,Far East University of South Korea | Cho H.H.,Jeonju Kijeon College | Kwon K.C.,Chungnam National University | Koo S.H.,Chungnam National University
Journal of Microbiology and Biotechnology | Year: 2014

This study aimed to characterize CTX-M producers of urinary E. coli and K. pneumoniae isolates and to determine the prevalence of plasmid-mediated antimicrobial resistance genes among them. Minimum inhibitory concentrations (MICs) were determined, and PCR and sequencing were performed. Among the 42 (82.3%) E. coli and 24 (77.4%) K. pneumoniae isolates containing blaCTX-M, blaCTX-M-14 and blaCTX-M-15 were detected in 23 and 19 E. coli isolates, respectively, and in 7 and 17 K. pneumoniae isolates, respectively. CTX-M producers of urinary E. coli and K. pneumoniae were resistant to multiple antibiotics and contained other antimicrobial resistance genes. CTX-M-15 producers contained more antimicrobial resistance genes than did CTX-M-14 producers. © 2014 by The Korean Society for Microbiology and Biotechnology.

Cho H.H.,Chungnam National University | Cho H.H.,Jeonju Kijeon College | Kwon K.C.,Chungnam National University | Sung J.Y.,Far East University of South Korea | Koo S.H.,Chungnam National University
Annals of Clinical and Laboratory Science | Year: 2013

Pseudomonas aeruginosa is one of the primary opportunistic pathogens responsible for nosocomial infections. Recently, sequence type 235 (ST235) has been found internationally in a multidrug-resistant clone and is involved in the dissemination of genes encoding IMP-6 and VIM-2. This study aimed to describe the prevalence of metallo-ß-lactamase (MBL), epidemiological relationship, and genetic characterization to aminoglycoside resistance in carbapenem-resistant P. aeruginosa isolates obtained from a tertiary hospital in Daejeon, Korea, from 2008 to 2012. Minimum inhibitory concentrations (MICs) of six antimicrobial agents were determined using the agar dilution method. PCR and DNA sequencing were used to identify MBL genes, class 1 integrons, and genes contributing to the aminoglycoside resistance phenotype. In addition, an epidemiological relationship was investigated by multilocus sequence typing (MLST). Eleven (16.2%) carbapenem-resistant isolates were MBL-producers; the major MBL type was IMP-6 (10 isolates). IMP-6-producing isolates were multidrug-resistant and belonged to ST235. All IMP- 6-producing isolates had class 1 integrons (5.5 Kb; blaIMP-6-qac-aacA4-blaOXA-1-addA1). We identified genetic characteristics in aminoglycoside genes between ST235 and non-ST235. All ST235 isolates contained aminoglycoside-modifying enzyme (AME) genes, whereas 23.5% of non-ST235 isolates contained AME genes. Development and spread of the aminoglycoside resistance gene in P. aeruginosa non-ST235 could result in multidrug resistance in the future. © 2013 by the Association of Clinical Scientists, Inc.

Cho H.H.,Jeonju Kijeon College | Kwon K.C.,Chungnam National University | Kim S.,Chungnam National University | Koo S.H.,Chungnam National University
Annals of Laboratory Medicine | Year: 2014

Background: Pseudomonas aeruginosa is a clinically important pathogen that causes opportunistic infections and nosocomial outbreaks. Recently, the type III secretion system (TTSS) has been shown to play an important role in the virulence of P. aeruginosa. ExoU, in particular, has the greatest impact on disease severity. We examined the relationship among the TTSS effector genotype (exoS and exoU), fluoroquinolone resistance, and target site mutations in 66 carbapenem-resistant P. aeruginosa strains. Methods: Sixty-six carbapenem-resistant P. aeruginosa strains were collected from patients in a university hospital in Daejeon, Korea, from January 2008 to May 2012. Minimum inhibitory concentrations (MICs) of fluoroquinolones (ciprofloxacin and levofloxacin) were determined by using the agar dilution method. We used PCR and sequencing to determine the TTSS effector genotype and quinolone resistance-determining regions (QRDRs) of the respective target genes gyrA, gyrB, parC, and parE. Results: A higher proportion of exoU+ strains were fluoroquinolone-resistant than exoS+ strains (93.2%, 41/44 vs. 45.0%, 9/20; P=0.0001). Additionally, exoU+ strains were more likely to carry combined mutations than exoS+ strains (97.6%, 40/41 vs. 70%, 7/10; P=0.021), and MIC increased as the number of active mutations increased. Conclusions: The recent overuse of fluoroquinolone has led to both increased resistance and enhanced virulence of carbapenem-resistant P. aeruginosa. These data indicate a specific relationship among exoU genotype, fluoroquinolone resistance, and resistance-conferring mutations. © The Korean Society for Laboratory Medicine.

Cho H.H.,Jeonju Kijeon College | Kwon G.C.,Chungnam National University | Kim S.,Chungnam National University | Koo S.H.,Chungnam National University
Journal of Microbiology and Biotechnology | Year: 2015

The emergence of carbapenem resistance among Pseudomonas aeruginosa is an increasing problem in many parts of the world. In particular, metallo-β-lactamases (MBLs) and AmpC β- lactamases are responsible for high-level resistance to carbapenem and cephalosporin. We studied the diversity and frequency of β-lactamases and characterized chromosomal AmpC β- lactamase from carbapenem-resistant P. aeruginosa isolates. Sixty-one carbapenem-resistant P. aeruginosa isolates were collected from patients in a tertiary hospital in Daejeon, Korea, from January 2011 to June 2014. Minimum inhibitory concentrations (MICs) of four antimicrobial agents were determined using the agar-dilution method. Polymerase chain reaction and sequencing were used to identify the various β-lactamase genes, class 1 integrons, and chromosomally encoded and plasmid-mediated ampC genes. In addition, the epidemiological relationship was investigated by multilocus sequence typing. Among 61 carbapenem-resistant P. aeruginosa isolates, 25 isolates (41.0%) were MBL producers. Additionally, 30 isolates producing PDC (Pseudomonas-derived cephalosporinase)-2 were highly resistant to ceftazidime (MIC50 = 256 μg/ml) and cefepime (MIC50 = 256 μg/ml). Of all the PDC variants, 25 isolates harboring MBL genes showed high levels of cephalosporin and carbapenem resistance, whereas 36 isolates that did not harbor MBL genes revealed relatively low-level resistance (ceftazidime, p < 0.001; cefepime, p < 0.001; imipenem, p = 0.003; meropenem, p < 0.001). The coexistence of MBLs and AmpC β-lactamases suggests that these may be important contributing factors for cephalosporin and carbapenem resistance. Therefore, efficient detection and intervention to control drug resistance are necessary to prevent the emergence of P. aeruginosa possessing this combination of β-lactamases. © 2015 by The Korean Society for Microbiology and Biotechnology.

Park H.H.,Chonbuk National University | Park I.S.,Chonbuk National University | Kim K.S.,Jeonju Kijeon College | Jeon W.Y.,Kwang Yang Health College | And 4 more authors.
Electrochimica Acta | Year: 2010

The selection of bioactive and electrochemically stable materials for implants having effective corrosion resistance during long-term use in the body is essential. In this study, the bioactive and electrochemical properties of titanium implant materials with a nanotube surface treatment and various types of posttreatments were examined. Two types of amorphous TiO2 nanotubes were grown homogeneously on the surface: one with a larger diameter (approximately 85 nm) and one with a smaller diameter (approximately 50 nm). Amorphous TiO2 nanotubes were partially crystallized to anatase and rutile by heat treatment at 500°C for 2 h. The corrosion potential (E corr) of the heat-treated sample (HT) had a novel value of 0.102V due to the stable TiO2 crystal phase compared to the.0.106V observed in the anodic oxidation sample (AN). The corrosion current density (I corr) ranged from 0.20 to 0.64μA/cm2 according to the post-treatment conditions. However, at 0.6 V, where a passive layer had formed, the corrosion resistance of the HT was approximately ten times that of the AN and untreated (UT) samples. After evaluating the hydroxyapatite (HA)-forming ability by immersion in a simulated body fluid (SBF) solution, the CP process induced the adsorption of Ca and P onto HT. A comparison of the time-dependent amount of Ca and P adsorption showed that Ca adsorption plays a role in determining the rate at which hydroxyapatite (HA) is formed. For the induction of HA formation, a level of Ca adsorption above a critical level is required. © 2010 Elsevier Ltd. All rights reserved.

PubMed | JeonJu KiJeon College, Chung - Ang University, Gachon University, Sahmyook University and Seoul National University
Type: Journal Article | Journal: Journal of alternative and complementary medicine (New York, N.Y.) | Year: 2016

Equine-assisted activity and training (EAAT) is thought to improve body balance and clinical symptoms in children with attention deficit hyperactivity disorder (ADHD). The study hypostheses were that EAAT would improve the clinical symptoms and gait balance in children with ADHD and that these improvements would be associated with increased brain connectivity within the balance circuit.A total of 12 children with ADHD and 12 age- and sex-matched healthy control children were recruited. EAAT consisted of three training sessions, each 70 minutes long, once a week for 4 weeks. Brain functional connectivity was assessed by using functional magnetic resonance imaging.After 4 weeks of EAAT, children with ADHD showed improved scores on the Korean ADHD scale (K-ARS), while the K-ARS scores of healthy children did not change. During the 4 weeks, the plantar pressure difference between the left foot and right foot decreased in both the healthy control group and the ADHD group. After 4 weeks of EAAT, healthy controls showed increased brain connectivity from the cerebellum to the left occipital lingual gyrus, fusiform gyrus, right and left thalami, right caudate, right precentral gyrus, and right superior frontal gyrus. However, children with ADHD showed increased brain connectivity from the cerebellum to the right insular cortex, right middle temporal gyrus, left superior temporal gyrus, and right precentral gyrus. In contrast, children with ADHD exhibited decreased brain connectivity from the cerebellum to the left inferior frontal gyrus.EAAT may improve clinical symptoms, gait balance, and brain connectivity, the last of which controls gait balance, in children with ADHD. However, children with ADHD who have deficits in the fronto-cerebellar tract did not exhibit changes in brain connectivity as extensive as those in healthy children in response to EAAT.

Jeon S.-N.,Ministry of National Defense | Shin H.,Jeonju Kijeon College | Lee H.-J.,Yonsei University
Osong Public Health and Research Perspectives | Year: 2012

Objectives: This study examined components in Rowe and Kahn's successful aging model to investigate their hierarchical order and led to a modification of the previous hierarchical order. Methods: To examine the hierarchical order of components, we constructed a structural equation model and verified those paths that have discrepancies in studies and/or potential inclusion or omission errors in the model. For this purpose, we analyzed 556 cases out of stratified and purposively sampled 600 elderly people living in the city of Jeonju during the study period (2011). Results: The paths with inclusion errors such as H3 [self-reported health → productive activity (SRH → PA)]: the effect of SRH on PA, and H6 [social network (SN) → PA]: the effect of SN on PA, were not directly but indirectly supported. The path with discrepancy, H4 [SN → physical-cognitive function (PCF)]: the effect of SN on PCFs, was statistically significant. The path with inclusion error and discrepancy, H8 (PCF → PA): the effect of PCF on PA, was not directly but indirectly supported. Also the path with the omission error, H2 [SRH → psychological trait (PT)]: the effect of SRH on PT, was statistically significant. The other paths in the hierarchical order of the model reported in previous studies were statistically significant. Conclusion: We verified new dynamics of constructs involved in successful aging, which would provide better understanding of Rowe and Kahn's successful aging model for Korean elderly people living in a medium-sized city. © 2012.

PubMed | Jeonju Kijeon College, Catholic University of Korea and Wonkwang University
Type: Journal Article | Journal: Annals of rehabilitation medicine | Year: 2016

To investigate the effects of hippotherapy on psychosocial and emotional parameters in children with cerebral palsy (CP) and their caregivers.Eight children with CP were recruited (three males and five females; mean age, 7.3 years; Gross Motor Function Classification System levels 1-3). Hippotherapy sessions were conducted for 30 minutes once weekly for 10 consecutive weeks in an indoor riding arena. The Gross Motor Function Measure (GMFM), Pediatric Balance Scale (PBS), and the Korean version of the Modified Barthel Index were evaluated. All children were evaluated by the Childrens Depression Inventory, Trait Anxiety Inventory for Children, State Anxiety Inventory for Children, Rosenberg Self Esteem Scale, and the Korean-Satisfaction with Life Scale (K-SWLS). Their caregivers were evaluated with the Beck Depression Inventory, the Beck Anxiety Inventory, and the K-SWLS. We assessed children and their caregivers with the same parameters immediately after hippotherapy.Significant improvements on the GMFM, dimension E in the GMFM, and the PBS were observed after hippotherapy compared with the baseline assessment (p<0.05). However, no improvements were detected in the psychosocial or emotional parameters in children with CP or their caregivers. None of the participants showed any adverse effects or accidents during the 10 weeks hippotherapy program.Hippotherapy was safe and effectively improved gross motor and balance domains in children with CP. However, no improvements were observed in psychosocial or emotional parameters.

PubMed | Yonsei University and Jeonju Kijeon College
Type: Journal Article | Journal: Journal of microbiology (Seoul, Korea) | Year: 2016

Mammalian -glutamyltranspeptidase (GGT) has been identified as a bone-resorbing factor. Since GGT of Bacillus subtilis exhibits similarity in their primary structure and enzymatic characteristics with mammalian GGTs, the bone-resorbing activity of bacterial GGT was examined in this study. Osteoclastogenesis was performed in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. A conditioned medium from GGT-overproducing B. subtilis culture showed significantly higher activity of osteoclast formation than a conditioned medium from wild-type B. subtilis culture. Recombinant GGT (rGGT) of wild-type B. subtilis and an enzymatic activity-defected rGGT of B. subtilis 2288 mutant were expressed in Escherichia coli and purified using His tag. Both purified rGGTs induced similar levels of osteoclastogenesis, suggesting that B. subtilis GGT possesses virulent bone-resorbing activity and its activity is probably independent of its enzymatic activity. Furthermore, a recombinant protein of B. subtilis GGT heavy subunit (Bs rGGT/H) showed strong activity of osteoclastogenesis while the light subunit failed to show strong activity, suggesting that the bone-resorbing activity is mainly located at the heavy subunit. More importantly, the GGT enzymatic activity may not be required for this virulence activity since the light subunit contains the catalytic pocket. In addition, B. subtilis rGGT stimulated mRNA expressions of receptor activator of nuclear factor kappa-B ligand (RANKL) and cyclooxygenase-2 (COX-2), while an osteoprotegerin inhibited the osteoclast formation induced by Bs rGGT/H. This is the first demonstration that bacterial GGT itself is sufficient to act as a bone-resorbing virulence factor via RANKL-dependent pathway. Therefore, it can be hypothesized that GGT of periodontopathic bacteria may play an important role as a virulence factor in bone destruction.

PubMed | Yonsei University and Jeonju Kijeon College
Type: Journal Article | Journal: PloS one | Year: 2016

Periodontitis is a very common oral inflammatory disease that results in the destruction of supporting connective and osseous tissues of the teeth. Although the exact etiology is still unclear, Gram-negative bacteria, especially Porphyromonas gingivalis in subgingival pockets are thought to be one of the major etiologic agents of periodontitis. Endothelin (ET) is a family of three 21-amino acid peptides, ET-1, -2, and -3, that activate G protein-coupled receptors, ETA and ETB. Endothelin is involved in the occurrence and progression of various inflammatory diseases. Previous reports have shown that ET-1 and its receptors, ETA and ETB are expressed in the periodontal tissues and, that ET-1 levels in gingival crevicular fluid are increased in periodontitis patients. Moreover, P. gingivalis infection has been shown to induce the production of ET-1 along with other inflammatory cytokines. Despite these studies, however, the functional significance of endothelin in periodontitis is still largely unknown. In this study, we explored the cellular and molecular mechanisms of ET-1 action in periodontitis using human gingival epithelial cells (HGECs). ET-1 and ETA, but not ETB, were abundantly expressed in HGECs. Stimulation of HGECs with P. gingivalis or P. gingivalis lipopolysaccharide increased the expression of ET-1 and ETA suggesting the activation of the endothelin signaling pathway. Production of inflammatory cytokines, IL-1, TNF, and IL-6, was significantly enhanced by exogenous ET-1 treatment, and this effect depended on the mitogen-activated protein kinases via intracellular Ca2+ increase, which resulted from the activation of the phospholipase C/inositol 1,4,5-trisphosphate pathway. The inhibition of the endothelin receptor-mediated signaling pathway with the dual receptor inhibitor, bosentan, partially ameliorated alveolar bone loss and immune cell infiltration. These results suggest that endothelin plays an important role in P. gingivalis-mediated periodontitis. Thus, endothelin antagonism may be a potential therapeutic approach for periodontitis treatment.

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