• Journal of dental hygiene science
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• v.15 no.2
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• pp.232-237
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• 2015

The water supplied from dental unit water systems (DUWS) in dentistry may be heavily contaminated with bacteria and thus may be a potential source of infection for both practice staff and patients. The aim of this study was to evaluate the level of heterotrophic bacteria and to confirm the presence of opportunistic pathogens from DUWS in student clinical simulation laboratory of college of dentistry. Water samples were collected from 36 ultrasonic scalers in student clinical simulation laboratory. The levels of heterotrophic bacteria in water samples were quantified by counting colony forming units (CFUs) on R2A agar media. In addition, opportunistic pathogens were detected by using the polymerase chain reaction (PCR) method. The mean CFUs were 16,095 CFU/ml for water samples and all of water samples exceeded current American Dental Association recommendations of 200 CFU/ml. Pseudomonas species and non-tuberculous Mycobacterium species were detected in the one sample and two samples, respectively, among the 36 water samples by the PCR with specific primers for these bacteria. Our study indicated that DUWS in student clinical simulation laboratory can cause potential infection in students and participants. This study suggested the dental unit water line management and wearing personal protective equipment in student clinical simulation laboratory will be needed to reduce bacterial contamination.

• The Korean Journal of Mycology
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• v.41 no.1
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• pp.52-55
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• 2013

Phoma glomerata (Corda) Wollenw. & Hochapfel is a pathogenic fungus causing spot diseases of plant leaves and fruits. This fungus is important in plant quarantine of seedlings and fruits in Korea. The aim of this study was to develop a sensitive and effective diagnostic method for P. glomerata detection in imported plants. The fungal species-specific PCR primers were designed based on the nucleotide sequences of the translation elongation factor 1 alpha gene and their specificity and sensitivity were tested. The designed primers named as PhoGlo-F and PhoGlo-R amplified specifically a 170 bp sized DNA band of the target gene from the genomic DNA of P. glomerata. No amplicon was produced from genomic DNAs of 16 other Phoma spp. and reference fungal species tested. Moreover, PhoGlo-F/PhoGlo-R primers successfully worked with real-time PCR technique. The detection limit of DNA content by conventional and real-time PCR were 10 pg and 1pg of the genomic DNA of P. glomerata, respectively. We believed that the developed makers would be very useful for P. glomerata detection.

• Journal of fish pathology
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• v.1 no.2
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• pp.103-110
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• 1988

For the rapid diagnosis of bacterial diseases of cultured fishes, the immunoperoxidase method was applied to the detection of $\beta$-haemolitic Streptococcus sp. strain KST-2 isolated from tilapia(Oreochromis niloticus). The suitability of field analysis and the sensitivity of the immunoperoxidase method was compared with those of the counterimmunoelectrophoresis(CIE) and the immunodiffusion(ID). Results of testing cross-reactivity which did not indicate any cross reactivity with other fish pathogens, this method was specific to Streptococcus sp. The sensitivity of this method was $1{\times}10^3CFU/ml$ which was at least $10^2$times greater than the CIE and $10^4$times greater than the ID. The immunoperoxidase method was more suitable for field application and more sensitive than other diagnostic techniques tested on this study.

• KSBB Journal
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• v.24 no.5
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• pp.432-438
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• 2009

Here, we demonstrated simple nucleic acid, RNA, concentration method using polymer micro chip containing glass bead ($100\;{\mu}m$). Polymer micro chip was fabricated by PDMS ($1.5\;cm\;{\times}\;1.5\;cm$, $100\;{\mu}m$ in the height) including pillar structure ($160\;{\mu}m\;(I)\;{\times}\;80\;{\mu}m\;(w)\;{\times}\;100\;{\mu}m\;(h)$, gap size $50\;{\mu}m$) for blocking micro bead. RNA could be adsorbed on micro glass bead at low pH by hydrogen bonding whereas RNA was released at high pH by electrostatic force between silica surface and RNA. Amount of glass beads and flow rate were optimized in aspects of adsorption and desorption of RNA. Adsorption and desorption rate was measured with real time PCR. This concentrated RNA was applied to amplification micro chip in which NASBA (Nucleic Acid Sequence Based Amplification) was performed. As a result, E.coli O157 : H7 in the concentration of 10 c.f.u./10 mL was successfully detected by these serial processes (concentration and amplification) with polymer micro chips. It implies this simple concentration method using polymer micro chip can be directly applied to ultra sensitive method to measure viable bacteria and virus in clinical samples as well as environmental samples.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.85-90
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• 2018

Sexually transmitted infections (STIs) are a global health concern and can cause serious complications such as miscarriage, premature birth, and pelvic infection in pregnant women. Therefore, accurate diagnosis and information on the epidemiologic trends are critical. However, studies of STI trends in Cheonan, South Korea, have not been conducted since 2012. We examined the STI trends in the Cheonan area after 2012. From January 2011 to September 2017, 3,362 cervical swab specimens from female patients were sampled at the Dankook University Hospital and analyzed by multiplex PCR. Of the 3,362 specimens, 1,281 were positive for pathogens (38.92%). A total of 1,893 pathogens were detected. Ureaplasma urealyticum, Mycoplasma hominis, and Chlamydia trachomatis were the most frequent pathogens, accounting for 36.29% (687/1,893), 30.16% (571/1,893), and 19.97% (378/1,893) of the pathogen-positive samples, respectively. In the 2009-2012 analysis, M. hominis was identified as the predominant pathogen in STI samples, whereas U. urealyticum was identified as the major pathogen in this study. In many countries, including South Korea and the United States, the rate of STIs is increasing, while a decreasing trend was observed in Cheonan.

• Research in Plant Disease
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• v.30 no.3
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• pp.219-228
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• 2024

Pepper anthracnose, caused by Colletotrichum spp., leads to a decrease in the quantity of pepper fruit production. Molecular diagnosis is crucial for rapid identification of pathogens and determination of fungicide resistance. However, the traditional process of isolating the pathogen, extracting genomic DNA, and analyzing the gene sequence is time-consuming, which delays rapid diagnosis. In this study, we introduced a method using conidia of Colletotrichum spp. instead of genomic DNA, eliminating the need for DNA extraction or special processing for diagnosis. To elucidate this method, sensitivity was assessed through polymerase chain reaction (PCR) and quantitative real-time PCR (qPCR) tests using internal transcribed spacer-based primer pairs. Both PCR and qPCR tests showed that detection is feasible with just one conidia, with over 1,000 conidia yielding results comparable to approximately 1 pg of genomic DNA. For amplifying the cytochrome b gene for quinone-outside inhibitor fungicide susceptibility testing, detection from a single conidium is achievable, but a stable PCR product is obtained by increasing the number of cycles to 35. Additionally, the addition of 10% grinding fresh chili pepper paste to V8-Juicea gar medium, which is known for inducing conidia rapidly from the isolates, resulted in 3.2 to 6.0 times more conidia compared to the commonly used potato dextrose agar medium, enhancing the potential for swift testing. Taken together, this study presents a direct utilization of pepper anthracnose conidia through PCR or qPCR, offering a valuable technique for amplifying target genes, such as the minimum conidial amount and barcode genes, for molecular identification of anthracnose disease in pepper through PCR and qPCR analysis.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.295-300
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• 2009

The specificity and sensitivity of oligonucleotide primers were examined for the rapid detection of Salmonella in meat samples. The oligonucleotide primers used in this study were designed with the modification of mdh and invA sequence in the chromosome of Salmonella Typhimurium. Through the subsequent analysis of the specificity and sensitivity of the primers, two types of oligonucleotide primers, SLM1 and SLT4 were selected for the detection of Salmonella genus specific and S. Typhimurium species specific, respectively. The lowest detection limit of each primer was represented as 1 cell per reaction when reacted with a prepared DNA solution. The detection efficiency of the two primers was analysed with beef and pork samples intentionally contaminated with a mixture of Salmonella culture, and three preparation methods -, namely direct reaction after extraction, enrichment after extraction, and DNA extraction after enrichment for PCR reaction, - were also compared. No differences were found in the results according to meat sources and preparation methods.

• Korean Journal of Plant Resources
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• v.16 no.1
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• pp.40-48
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• 2003

Cylindrocarpon destructans is the major pathogen inducing the root rot disease in ginseng. Up to now, there is no reliable and convenient method to analyze the spore density or population of this pathogen in ginseng-growing soil or any contaminated farmlands. Therefore, it will be very valuable to develop a new and reliable method in detecting the spore of this pathogen. In this study, a molecular biological technique using two step nested PCR method, was developed. Two universal ITS primers, ITS5F and ITS4R were used in the first round of PCR to amplify a fragment of ITS region from the genomic DNA of C. destructans. The specific prmers Nest 1 and Nest 2 were designed and used in the second round of PCR to amplify a inner fragment from the first round PCR product of C. destructans. C. destructans spore, only soil samples from the diseased ginseng farm produced the positive bands, suggesting its usefulness in detecting the C. destructans spores in soil samples. Thus it is recommended to first extract the whole genomic DNA from soil samples and use it for the PCR reaction, thereby eliminating the inhibitory activity of soil components.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.332-335
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• 2015

Taphrina wiesneri, a pathogen of cherry witches' broom, is highly pathogenic to Prunus yedoensis Matsumura which are widely planted in parks and streets in South Korea. In order to control the disease, it is crucial to know the life cycle of the fungus. We attempted to detect the fungus tentatively overwintering in shoots and branches of cherry trees both having witches' broom and healthy before flowering and leafing in spring using PCR with species-specific primer set (TwITSF and TwITSR). Genomic DNAs were extracted from the symptomatic and the asymptomatic shoots or branches. Results indicated that T. wiesneri is present in leaf buds and inner bark not only in symptomatic branches but also in the asymptomatic branches in diseased trees. However, the fungus was not detected in flower buds of the symptomatic trees and any samples of healthy trees.

• Korean Journal Plant Pathology
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• v.3 no.1
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• pp.8-12
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• 1987

Fusarium oxysporum, F. moniliforme, F. solani, F. equiseti, F. semitectum, and F. sporotrichioides were detected from seeds, roots and cultivated soil of Phaseolous vidissimus collected from Kyung-gi Provincial Rural Development Administration. The rate of seedling desease incidence was $60\%$ by testing of seed germination using a large petri-dish. According to the blotter method, F. moniliforme showed $7\%$ infection at seed-coat and $2\%$ at cotyledon and embryo. Their pathogenicities of F. moniliforme, F. semitectum, F. equiseti, and F. sporotrichioides isolated from seeds were recognized on seedlings by water-agar test tube methods. F. oxysporum and F. solani isolated from infected-roots had their pathogenicity by water-agar test tube method but were weakly pathogenic by soil treatment method. Their pathogenicities of F. oxysporum. F. solani and F. uiseti isolated from cultivated-soil were recognized by water-agar test tube method. These F. oxysporum and equiseti isolates had their pathogenicities but F. solani was weakly pathogenic by soil treatment method.