• Parasites, Hosts and Diseases
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• v.55 no.2
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• pp.159-165
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• 2017

Vivax malaria reemerged in Korea in 1993 and the outbreak has been continued with fluctuating numbers of annual indigenous cases. Understanding the nature of the genetic population of Plasmodium vivax circulating in Korea is beneficial for the knowledge of the nationwide parasite heterogeneity and in the implementation of malaria control programs in the country. Previously, we analyzed polymorphic nature of merozoite surface protein-1 (MSP-1) and MSP-$3{\alpha}$ in Korean P. vivax population and identified the Korean P. vivax population has been diversifying rapidly, with the appearance of parasites with new genetic subtypes, despite the recent reduction of the disease incidence. In the present study, we developed simple PCR-RFLP methods for rapid subtyping of MSP-1 and MSP-$3{\alpha}$ of Korean P. vivax isolates. These PCR-RFLP methods were able to easily distinguish each subtype of Korean P. vivax MSP-1 and MSP-$3{\alpha}$ with high accuracy. The PCR-RFLP subtyping methods developed here would be easily applied to massive epidemiological studies for molecular surveillance to understand genetic population of P. vivax and to supervise the genetic variation of the parasite circulating in Korea.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.1
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• pp.17-23
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• 2015

A fine needle aspiration biopsy (FNAB) is the primary means of distinguishing benign from malignant in thyroid nodules. However, between 10 and 30% of the FNABs of thyroid nodules are diagnosed as 'indeterminate'. A molecular method is needed to reduce unnecessary surgery in this group. In Korea, most thyroid cancer is classic papillary type and BRAFV600E mutation is highly prevalent. Thus, this study compared the pyrosequencing method with the conventional direct DNA sequencing and PCR-RFLP analysis and investigated the evaluation of preoperative BRAFV600E mutation analysis as an adjunct diagnostic method with routine FNABs. Sixty-five (78.3%) of 83 histopathologically diagnosed malignant nodule revealed positive BRAFV600E mutation on pyrosequencing analysis. In detail, 65 (83.8%) of 78 papillary thyroid carcinomas sample showed positive BRAFV600E mutation. None of 29 benign nodules had in pyrodequencing, direct DNA sequencing and PCR-RFLP. Out of 31 thyroid nodules classified as 'indeterminate' on cytological examination preoperatively, 28 cases turned out to be malignant: 24 papillary thyroid carcinomas. Among that, 16 (66.7%) classic papillary thyroid carcinomas had BRAFV600E mutation. Among 65 papillary thyroid carcinomas with positive BRAFV600E mutation detected by pyrosequencing analysis, each 3 cases and 5 cases did not show BRAFV600E mutation by direct DNA sequencing and PCR-RFLP analysis. Therefore, pyrosequencing was superior to direct DNA sequencing and PCR-RFLP in detecting the BRAFV600E mutation of thyroid nodules (p =0.027). Detecting BRAFV600E mutation by pyrosequencing was more sensitivity, faster than direct DNA sequencing or PCR-RFLP.

• Journal of Microbiology and Biotechnology
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• v.28 no.2
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• pp.338-346
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• 2018

Two molecular epidemiologic methods, IS6110 restriction fragment length polymorphism (IS6110-RFLP) and 24-locus mycobacterial interspersed repetitive unit-variable-number tandem repeat (MIRU-VNTR), are used worldwide in studies of Mycobacterium tuberculosis (MTB). Conversely, because of its poor resolution, pulsed-field gel electrophoresis (PFGE) is not widely used for MTB. In this study, we improved the 24-locus MIRU-VNTR and PFGE protocols and compared the effectiveness of these approaches for the molecular typing of MTB using 75 clinical isolates obtained from a cohort investigation of high-risk populations infected with MTB. The 24-locus MIRU-VNTR method demonstrated superior discriminatory ability, followed by PFGE and IS6110-RFLP. Next, we analyzed six isolates with clear epidemiologic connections; that is, isolates from patients who attended the same school. IS6110-RFLP and PFGE identified these samples as the same type. By contrast, according to MIRU-VNTR, two isolates differed from four other isolates at one locus each; one isolate was identified as Mtub29 and the other as QUB-26. In summary, the 24-locus MIRU-VNTR assay was the most useful molecular typing method among the three methods investigated due to its discriminatory power, short time required, and availability as an epidemiologic investigation tool. PFGE was the second-best method. Compared with the other loci assessed in the 24-locus MIRU-VNTR assay, the Mtub29 and QUB-26 loci appeared to exhibit greater variability during transmission.

• Applied Biological Chemistry
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• v.36 no.3
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• pp.139-145
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• 1993

The methods of isoelectric focusing of 4 isozymes in polyacrylamide horizontal slab gels and restriction fragment length polymorphisms (RFLPs) were applied to characterize the biochemical phenotypes of 19 cultivars of barley. Among 19 barley cultivars screened, 7 esterase, 3 phosphoglucose isomerase, 4 peroxidase and 2 alcohol dehydrogenase isozyme phenotypes were distinguished by isoelectric focusing. When purified DNA of each cultivar was digested with restriction enzyme EcoRV and analyzed its RFLPs with barley DNA markers pMSU 51 or pMSU 71, two distinct RFLP patterns were shown. Based on the four isozymes and two RELP polymorphisms, 19 cultivars of barley were classified into 13 biochemical phenotypes. Phylogenetical relationships among 13 biochemical phenotypes classified were determined using Nei's F-statistics and the phylogenetic dendrogram was constructed.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.362-368
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• 1997

Five formae speciales of Fusarium oxysporum in Korea were examined using RFLP analysis to find the possibility for classification and analyze genetic variations. DNAs from F. oxysporum f. sp. lycopersici, cucumerinum, fragariae, garlic and sesami were used with three recombinant probes such as pFC46, pFC52 and pFC57. Distinct differences among five formae speciales of this fungus were detected in RFLP band patterns based on southern hybridization of genomic DNA using each recombinant clone, which was a repetitive copy probe. Strains belong to four formae speciales could be very stable in genetic variation except f. sp. sesami which has more variation than the others based on the RFLP analysis. They formed their own cluster which has high similarity within the same formae specialis resulted from the UPGMA analysis for genetic relationship analysis and each cluster represented its own formae specialis. The method using three recombinant DNA probes could be a good tool for classification of formae speciales in F. oxysporum.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1701-1704
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• 2003

Melatonin regulates circadian rhythms and reproduction changes in seasonally reproductive mammals through binding to high-affinity, G-protein-coupled receptors. Small Tail Han sheep that has significant characteristics of high prolificacy and nonseasonal ovulatory activity is an excellent local sheep breed in P. R. China. The exon 2 of the ovine melatonin receptor 1a (MTNR1A) gene was amplified and a uniform fragment of 824 bp was obtained in 150 ewes of Small Tail Han sheep. The 824 bp PCR product was digested with restriction endonucleases Mnl I and Rsa I, and genetic polymorphism was detected by PCR-RFLP. Polymorphic Mnl I site was detected at base position 605 of the exon 2 of the MTNR1A gene. There were two kinds of genotypes in Small Tail Han sheep, AB (303 bp, 236 bp/67 bp) and BB (236 bp/67 bp, 236 bp/67 bp). The results indicated that genotype AA (303 bp, 303 bp) at Mnl I-RFLP site did not exist in non-seasonal estrous Small Tail Han sheep, which suggested that there was an association between genotype AA (303 bp, 303 bp) and reproductive seasonality in sheep. Polymorphic Rsa I site was detected at base position 604 of the exon 2 of the MTNR1A gene. Three kinds of genotypes were found in Small Tail Han sheep, AA (290 bp, 290 bp), AB (290 bp, 267 bp/23 bp) and BB (267 bp/23 bp, 267 bp/23 bp). Least squares means of litter size in the first parity and the second parity for genotype AA (290 bp, 290 bp) at Rsa I-RFLP site were 0.43 and 1.06 more than those for genotype AB (290 bp, 267 bp/23 bp) in Small Tail Han sheep.

• Parasites, Hosts and Diseases
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• v.35 no.4
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• pp.271-276
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• 1997

We tried to compare the three kinds oi Metagonimur species. M. Wokognulci, Ifetafonimus Miyata type, and M. tnknhashii, which were Know to be distributed in Korea with polymerase chain reaction based-restriction fragment length polymorphism (PCR- RFLP) patterns. We amplified the internal transcribed spacer 1 (ITSI) site of ribosomal RNA and mitochondrial cytochrome c oxidase I (mCOI) gene. The restriction patterns of ITSI gene loth Rsc I, ALu I and Msp I showed multiple fragmented bands of different sizes between three kinds of Metcgonimus. In case of mc01 gene, Rsc I and Alu I enzymes produced differentially fragmented band patterns. According to the parsimony analysis of PCR-RFLP patterns, the estimated genetic divergence between M Wokognwai and Metasoninus Miyata type was 0.034880, between Metusoninus Miyata type and M. tckc- hushii was 0.028098, between M. wokogawai and M. tnkahashii was 0.018179. It is suggested that Metasonimus Miyata type may be separate species and evolutionize at the older time than the other two species.

• KSBB Journal
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• v.19 no.1
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• pp.72-77
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• 2004

The aim of this study was to isolate and identify the spoilage bacteria in the low salt cucumber brine. The PCR amplicons comprising a portion of the 16S rRNA gene of the isolated colonies were directly sequenced and the untrimmed whole sequencing results of the unknown strains were aligned with the type strains using BLAST of NCBI. Then Sequence Aligner and Sequence Match of RDP confirmed the outcome. The identified isolates were eight species and belong to three genuses: Clostridium, Lactobacillus, and Bacillus. The RFLP pattern of the 16S rRNA gene of isolates verified the identified species. From now on the complex spoiling process of law salt fermented cucumber could be analyzed using the isolated species individually or with certain combinations.

• Korean Journal of Microbiology
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• v.51 no.1
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• pp.21-30
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• 2015

The goal of this study was to identify relationships between the composition of sulfate reducing bacterial assemblages and terminal restriction fragment length polymorphism (T-RFLP) patterns in rice paddy and dry farming soils. Samples of organic farming soils, conventional farming soils, and dry field farming soils were collected in August and November. Analyses of the soil chemical composition revealed similar total nitrogen, total carbon and total inorganic phosphorus levels; however, the moisture content and total carbon were higher than in the other soils in both August and November, respectively. Sulfate reducing bacteria utilizing lactic acid were more widely distributed than those that used acetic acid, and the number of sulfate reducing bacteria in organic farming soil was most abundant. Phylogenetic analysis based on 181 clones revealed that most showed low similarity with cultured sulfate reducing bacteria, but more than 90% similarity with an uncultured sulfate reducing bacteria isolated from the environment. T-RFLP analysis revealed that fragments of 91, 357, 395, and 474 bp were most common, and the community structure of sulfate reducing bacteria changed seasonally.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.292-303
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• 1998

The arbitrary primer polymerase chain reaction(AP-PCR) and Southern blot restriction fragment length polymorphism(RFLP) were used to genotype the cariogenic pathogen S. mutans in children. Following the morphologic chracteristics of colony on selective medium for S. mutans, total genomic DNA from 155 strains was extracted by conventional methods. Among 155 strains, 143 strains (92.3%) were confirmed S. mutans by PCR with dexA gene and 114 strains were used in this study. Three random sequence 10-base oligonucleotide primers were chosen for AP-PCR. The amplified DNA products were separated electrophoretically in a 2% agarose gel containing ethidium bromide and the banding patterns were compared among different strains. For RFLP analysis, DNA was digested with EcoRI and BamHI, separated on a 0.7 % agarose gel and transferred to a nylon membrane. The membrane was probed with a previously characterised 1.6 kilobases (kb) DNA fragment cloned from gtf B gene of S. mutans. The probe was labeled with isotope[$^{32}P-{\alpha}CTP$], and hybridized fragments were detected with intensifying screen. AP-PCR produced 4-8 DNA bands in the 0.25-10 kb regions and distinguished 9, 10 or 12 genotypes, depending on the specific primer used. Southern blot RFLP analysis revealed 2 hybridization patterns consisting of 1 DNA fragments 450, 500 bp. These results indicate that AP-PCR is more discriminative method for genotyping of S. mutans.