• Journal of Microbiology and Biotechnology
• /
• v.27 no.9
• /
• pp.1716-1723
• /
• 2017

The rapid dissemination of extended-spectrum ${\beta}$-lactamase (ESBL)-producing Escherichia coli has significantly contributed to public health hazard globally. A total of 281 E. coli strains recovered from pigs and chickens between 2009 and 2015 in South Korea were analyzed for ESBL production. ESBL phenotypes were recognized in 14 E. coli isolates; ten and three ESBL-producing isolates carried only $bla_{CTX-M}$ and $bla_{CMY}$ genes, respectively, and one isolate harbored both genes. The predominant CTX-M and CMY types were CTX-M-15 (n = 8) and CMY-2 (n = 3). We also detected ESBL-producing isolates harboring $bla_{CTX-M-65}$, $bla_{CTX-M-14}$, $bla_{CMY-6}$, $bla_{DHA-1}$, and $bla_{TEM-1}$ genes. All ESBL-producing isolates showed resistance to the extent of the fourth generation cephalosporins, along with multidrug resistance. CTX-M-15-producing isolates showed higher MIC values than CTX-M-14- and CTX-M-65-producing isolates. The $bla_{CTX-M}$ and $bla_{CMY}$ genes have the potential to be transferable. The spreading of $bla_{CMY}$ and $bla_{CTX-M}$ genes was arbitrated mainly via Frep and IncI1 plasmids. Our isolates showed clonal diversity in PFGE analysis. This is the first report of E. coli isolates carrying $bla_{CMY-6}$ in chicken from South Korea. The emergence of CMY-6 ESBLs in a population of poultry suggests that extensive screening with long-term surveillance is necessary to prevent the dissemination of ESBL from chicken to human.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.281.2-281.2
• /
• 2013

Since heavy metal ions included in water or food resources have critical effects on human health, highly sensitive, rapid and selective analysis for heavy metal detection has been extensively explored by means of electrochemical, optical and colorimetric methods. For example, quantum dots (QDs), such as semiconductor QDs, have received enormous attention due to extraordinary optical properties including high fluorescence intensity and its narrow emission peaks, and have been utilized for heavy metal ion detection. However, the semiconductor QDs have a drawback of serious toxicity derived from cadmium, lead and other lethal elements, thereby limiting its application in the environmental screening system. On the other hand, Graphene oxide (GO) has proven its superlative properties of biocompatibility, unique photoluminescence (PL), good quenching efficiency and facile surface modification. Recently, the size of GO was controlled to a few nanometers, enhancing its optical properties to be applied for biological or chemical sensors. Interestingly, the presence of various oxygenous functional groups of GO contributes to opening the band gap of graphene, resulting in a unique PL emission pattern, and the control of the sp2 domain in the sp3 matrix of GO can tune the PL intensity as well as the PL emission wavelength. Herein, we reported a photoluminescent GO array on which heavy metal ion-specific DNA aptamers were immobilized, and sensitive and multiplex heavy metal ion detection was performed utilizing fluorescence resonance energy transfer (FRET) between the photoluminescent monolayered GO and the captured metal ion.

• Korean Journal of Plant Resources
• /
• v.14 no.3
• /
• pp.235-240
• /
• 2001

Polymerase chain reaction (PCR) is used in a wide array of researches in plant molecular genetics and breeding. However, considerable time and cost are still required for the preparation of DNA suitable for reliable PCR results, especially in plant species containing high amounts of polyphenols. To reduce time and effort for PCR-based analysis, a simplified but reliable method was developed by a combinational employment of a simple and fast DNA extraction procedure and BLOTTO (Bovine Lacto Transfer Technique Optimizer) in reaction mixture. Genomic DNAs prepared by one-step extraction method from recalcitrant plant species such as Rubus coreanus, apple, grape and lettuce were successfully amplified by random primers in the reaction mixture containing 2 to 4% BLOTTO. Successful amplification of ${\gamma}$-TMT transgene in lettuce transformants by the specific primers was also achieved in the same condition, making rapid screening of positive transformants possible. Our results suggest that use of a simple DNA extraction procedure and incorporation of BLOTTO in reaction mixture in combination can reduce time and effort required for the analyses of a large number of germplasms and transformants by PCR-based techniques.

• Journal of Applied Biological Chemistry
• /
• v.64 no.3
• /
• pp.277-284
• /
• 2021

The emergence and rapid spread of the potentially fatal coronavirus disease 2019, caused due to infection by severe acute respiratory syndrome coronavirus-2, has led to worldwide interest in developing functional bioactive ingredients that act as immunomodulatory agents. In this study, we aimed to characterize Carica papaya extract and explore its potential as an immunomodulator by performing in vitro cell screening. Papaya leaf water extract (PLW) was found to significantly increase the levels of nitric oxide (NO) and prostaglandin E₂ (PGE₂) by upregulating inducible nitric oxide synthase and cyclo-oxygenase-2 activity, respectively. Additionally, PLW increased the production of tumor necrosis factor-α and interleukin 1β in RAW 264.7 cells. Furthermore, PLW activated the expression of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) but not that of p38 mitogen-activated protein kinase. These results indicate that PLW increased the production of NO, PGE₂, and pro-inflammatory cytokines by activating the JNK and ERK pathways in macrophages, thus demonstrating immunomodulatory properties. Finally, high-performance liquid chromatography fingerprint analysis indicated the presence of rutin, narirutin, and ρ-coumaric acid in PLW (6.30, 119.76, and 47.25 ppm, respectively). Treating cells with these compounds at non-toxic concentrations had no effect on NO production. Taken together, these results suggest that PLW may have potential as an immunity-enhancing supplement.

• Journal of Yeungnam Medical Science
• /
• v.35 no.2
• /
• pp.205-212
• /
• 2018

Background: Brain volume is associated with dementia and depression in the elderly. An easy way to predict relative brain volume is to measure head circumference. In this study, we investigated the relationship between head circumference and cognition as well as depression in a non-demented elderly community. Methods: Baseline and follow-up surveys were conducted in 2007 and 2010. At baseline, community residents aged 65 years or over (n=382) within a rural area of South Korea were screened for dementia and symptoms of depression and were followed using the same screening battery after 3 years (n=279). Data from anthropometric measurements (head circumference, height, and body weight), demographics, and blood tests were gathered. Neuropsychological tests, including the Korean version of mini-mental state examination (K-MMSE), clinical dementia rating (CDR) including the CDR-sum of boxes, the Korean version of instrumental activities of daily living, and geriatric depression scale (GDS), were performed. None of the 279 subjects followed were demented. Results: Baseline performance on the K-MMSE and GDS was poorer for participants with smaller head circumferences. Follow-up performance on the MMSE was also poorer for participants with smaller head circumferences. Interestingly, participants with smaller head circumference showed worse GDS scores at baseline but on follow-up examination, participants with larger head circumference showed rapid worsening than those with smaller head circumference with marginal significance by ANOVA test. In regression coefficient analysis, GDS decline showed significant difference. Conclusion: Head circumference was not associated with cognitive change but was associated with symptoms of depression in non-demented community residents.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.1
• /
• pp.92-103
• /
• 2021

Lactobacillus casei, one of the most widely used probiotics, has been reported to alleviate multiple diseases. However, the effects of this species on intestinal diseases are strain-specific. Here, we aimed to screen L. casei strains with inflammatory bowel disease (IBD)-alleviating effects based on in vitro physiological characteristics. Therefore, the physiological characteristics of 29 L. casei strains were determined, including gastrointestinal transit tolerance, oligosaccharide fermentation, HT-29 cell adhesion, generation time, exopolysaccharide production, acetic acid production, and conjugated linoleic acid synthesis. The effects of five candidate strains on mice with induced colitis were also evaluated. The results showed that among all tested L. casei strains, only Lactobacillus casei M2S01 effectively relieved colitis. This strain recovered body weight, restored disease activity index score, and promoted anti-inflammatory cytokine expression. Gut microbiota sequencing showed that L. casei M2S01 restored a healthy gut microbiome composition. The western blotting showed that the alleviating effects of L. casei M2S01 on IBD were related to the inhibition of the NF-κB pathway. A good gastrointestinal tolerance ability may be one of the prerequisites for the IBD-alleviating effects of L. casei. Our results verified the efficacy of L. casei in alleviating IBD and lay the foundation for the rapid screening of L. casei strain with IBD-alleviating effects.

• International Journal of Contents
• /
• v.17 no.1
• /
• pp.37-53
• /
• 2021

With the advent of the 5G era, smart phones and communications network technology have progressed, and mobile short video of people's life can be made, Of the new tools of communication, at present, China's social short video industry has shown rapid development, and the most representative of the short video app is Douyin (international version: Tiktok). Under the background of Uses and Gratifications Theory, this study discusse the relationship between Douyin users' preference degree, use motivation, use satisfaction and attention intention. This study divides the content of Douyin video into 10 categories, selects the form of an online questionnaire survey, uses SPSS software to conduct quantitative analysis of 202 questionnaires after screening, and finally draws the following conclusions: (1) The content preference degree of Douyin short video (the high group and low group) is different in users' use motivation, users' satisfaction degree and users' attention intention. ALL results are within the range of statistical significance.(2) Douyin users' video content preference degree has a positive impact on users' use motivation, users' satisfaction degree, and users' attention intention. (3) Douyin users' motivation has a positive impact on users' satisfaction and user' attention intention. (4) Douyin users' satisfaction degree has a positive impact on users' attention intention. Based on the research results, we suggest that Douyin platform pushes videos according to users' preferences. In addition, as the preference degree has an impact on users' motivation, satisfaction degree and attention intention of using the platform, it is important that the platform's focus should to pay attention to the preference degree of users. Collecting users' preferences at the early stage of users' entering the platform is a good way to learn from, and doing a good job of big data collection and management in the later operation.

• Journal of Audiology & Otology
• /
• v.24 no.3
• /
• pp.133-139
• /
• 2020

Background and Objectives: The Gaps-In-Noise (GIN) test is a clinically effective measure of the integrity of the central auditory nervous system. The GIN procedure can be applied to a pediatric population above 7 years of age. The present study conducted the GIN test to compare the abilities of auditory temporal resolution among typically developing children, children with speech sound disorder (SSD), and children with cognitive difficulty (CD). Subjects and Methods: Children aged 8 to 11 years-(total n=30) participated in this study. There were 10 children in each of the following three groups: typically developing children, children with SSD, and children with CD. The Urimal Test of Articulation and Phonology was conducted as a clinical assessment of the children's articulation and phonology. The Korean version of the Wechsler Intelligence Scale for Children-III (K-WISC-III) was administered as a screening test for general cognitive function. According to the procedure of Musiek, the pre-recorded stimuli of the GIN test were presented at 50 dB SL. The results were scored by the approximated threshold and the overall percent correct score (%). Results: All the typically developing children had normal auditory temporal resolution based on the clinical cutoff criteria of the GIN test. The children with SSD or CD had significantly reduced gap detection performance compared to age-matched typically developing children. The children's intelligence score measured by the K-WISC-III test explained 37% of the variance in the percent-correct score. Conclusions: Children with SSD or CD exhibited poorer ability to resolve rapid temporal acoustic cues over time compared to the age-matched typically developing children. The ability to detect a brief temporal gap embedded in a stimulus may be related to the general cognitive ability or phonological processing.

• Korean Journal of Audiology
• /
• v.24 no.3
• /
• pp.133-139
• /
• 2020

Background and Objectives: The Gaps-In-Noise (GIN) test is a clinically effective measure of the integrity of the central auditory nervous system. The GIN procedure can be applied to a pediatric population above 7 years of age. The present study conducted the GIN test to compare the abilities of auditory temporal resolution among typically developing children, children with speech sound disorder (SSD), and children with cognitive difficulty (CD). Subjects and Methods: Children aged 8 to 11 years-(total n=30) participated in this study. There were 10 children in each of the following three groups: typically developing children, children with SSD, and children with CD. The Urimal Test of Articulation and Phonology was conducted as a clinical assessment of the children's articulation and phonology. The Korean version of the Wechsler Intelligence Scale for Children-III (K-WISC-III) was administered as a screening test for general cognitive function. According to the procedure of Musiek, the pre-recorded stimuli of the GIN test were presented at 50 dB SL. The results were scored by the approximated threshold and the overall percent correct score (%). Results: All the typically developing children had normal auditory temporal resolution based on the clinical cutoff criteria of the GIN test. The children with SSD or CD had significantly reduced gap detection performance compared to age-matched typically developing children. The children's intelligence score measured by the K-WISC-III test explained 37% of the variance in the percent-correct score. Conclusions: Children with SSD or CD exhibited poorer ability to resolve rapid temporal acoustic cues over time compared to the age-matched typically developing children. The ability to detect a brief temporal gap embedded in a stimulus may be related to the general cognitive ability or phonological processing.

• Journal of Veterinary Science
• /
• v.23 no.5
• /
• pp.32.1-32.11
• /
• 2022

Background: Classical swine fever (CSF) is a severe infectious disease of pigs that causes significant economic losses to the swine industry. Objectives: This study developed a solid-phase blocking enzyme-linked immunosorbent assay (spbELISA) method for the specific detection of antibodies against the CSF virus (CSFV) in porcine serum samples. Methods: A spbELISA method was developed based on the recombinant E2 expressed in Escherichia coli. The specificity of this established spbELISA method was evaluated using reference serum samples positive for antibodies against other common infectious diseases. The stability and sensitivity were evaluated using an accelerated thermostability test. Results: The spbELISA successfully detected the antibody levels in swine vaccinated with the C-strain of CSFV. In addition, the detection ability of spbELISA for CSFV antibodies was compared with that of other commercial ELISA kits and validated using an indirect immunofluorescence assay. The results suggested that the spbELISA provides an alternative, stable, and rapid serological detection method suitable for the large-scale screening of CSFV serum antibodies. Conclusions: The spbELISA has practical applications in assessing the vaccination status of large pig herds.