• Journal of fish pathology
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• v.34 no.1
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• pp.39-46
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• 2021

Tetracycline (TC) is one of the antibiotics used for treatment of bacterial infection in Korea. Inadequate usage and abuse cause the resistance to antibiotics, like Tetracycline, Erythromycin, and Fluoroquinolone. It can also affect severe economic loss in aquaculture field in Korea. We isolated 101 bacterial samples from diseased fish at aquaculture sites in Gyeonggi-do during 2015~2018. Minimum inhibitory concentration (MIC) method has been used to determine distribution and to identify bacterial isolates resistant to antibiotics including Oxytetracycline (OTC), Ampicillin (AMP), Clindamycin (CLI), Enrofloxacin (ENRO), Gentamycin (GEN). TC resistant isolates were confirmed antibiotic resistant genes by conventional PCR. Bacterial isolates were identified as Aeromonas spp. (43.5%), Pseudomonas spp. (4.0%) and Vibrio spp. (5.0%). It was confirmed that multi-resistant isolates (77.2%) were predominant over single-resistant one (22.8%). TC resistant genes like tet(A), tet(D), tet(E), tet(G), tet(M), and tet(S) were detected and tet(A) was the most prevalent. Aeromonas spp. is a dominant strain in bacterial infections in fishes of aquaculture sites, and further investigation on various antibiotic resistance genes will be needed for clear understanding of aquaculture sites in Gyeonggi-do.

• Research in Plant Disease
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• v.28 no.4
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• pp.231-236
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• 2022

Oxypetalum coeruleum, commonly known as Tweedia, is a perennial herbaceous plant of the Apocynaceae family native to southern Brazil and Uruguay. Tweedia plants are grown as one of the most popular ornamental flowers for floral arrangement in Korea. In May 2021, several tweedia plants in a single greenhouse in Gimje, Jeollabuk-do were found to show virus-like symptoms including necrotic rings, vein-clearing, chlorotic mottle, and mosaic on the leaves, and necrosis on the stems. Here, we have identified tomato spotted wilt virus (TSWV) in symptomatic tweedia leaves by applying high-throughput RNA sequencing. In the result, a single infection by TSWV was verified without mixed infections of different virus species. To confirm the presence of TSWV, a reverse transcription polymerase chain reaction was performed with a specific primer set to the N gene of TSWV. The complete genomic sequence of L, M, and S segments of TSWV 'Oxy' isolate were determined and deposited in GenBank under accession numbers LC671525, LC671638, and LC671639, respectively. In the phylogenetic tree analysis by maximum likelihood method, 'Oxy' isolate showed a high relationship with TSWV 'Gumi' isolate from Gerbera jamesonii in Gyeongsangbuk-do, Korea; for all three RNA segments. To our knowledge, this is the first report of TSWV infection of O. coeruleum in Korea.

• Journal of Naturopathy
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• v.8 no.1
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• pp.1-10
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• 2019

Purpose: The purpose of this study was to investigate the increase or decrease of important intestinal beneficial bacteria and inhibitory bacteria in 30 stools of clinical subjects after ingesting Zen fermentation broth as a mixed microbial fermentation solution for eight weeks. Methods: Intestinal bacteria were identified by PCR amplification using specific primers. Results: Bifidobacterium genus gi% of test group ingested Zen-fermented broth was 55.15% before and 70.1% after ingestion, so it was a significant difference (p<.009). Lactobacillus genus of the test group was 46.87% before and 60.91% after ingestion, it was a significant difference (p<.01). Clostridium genus of the test group was 85.64% before and 65.99% after ingestion. There was a significant difference (p<.017) as the pre-post-difference decreased to -19.65%. Bacteroides genus of the test group was 17.11% before and 20.22% after ingestion. There was a significant difference (p<.048) as the pre-post-difference increased to 3.11%. Prevotella genus of the test group was 14.01% before and 16.79% after ingestion, so it was not a significant difference. Conclusions: Intestinal bacteria increased the proliferation of beneficial bacteria and suppressed harmful bacteria in the intestines after ingesting the Zen-fermented broth of the mixed microorganism. The Zen fermentation broth evaluated as a beneficial drink for intestinal health.

• Journal of Naturopathy
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• v.7 no.2
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• pp.27-38
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• 2018

Purpose: The purpose of this study was to investigate whether intestinal proliferation is promoted in beneficial intestinal bacteria or decreased in harmful bacteria before and after ingesting Bacillus fermentation broth (ENM) for 8 weeks in the 16 subjects. Method: Intestinal bacteria were identified by PCR amplification using specific 16S rRNA primers. Results: The Bifidobacterium gene index(%)(gi%) increased to 58.92% in the control group and 69.53% in the test group after the ingestion of ENM, but there was no significant difference. Lactobacillus gi% increased significantly (49.37% in the control and 66.43% in the test) (p<.029). Clostridium gi% was significantly decreased after treatment (83.16% in the control and 67.76% in the test) (p<.077). Bacteroides gi% increased significantly (12.58% in the control and 20.87% in the test) after ingesting (p<.095). Prevotella gi% increased significantly (7.55% in the control and 17.28% in the test) after ingesting (p<.005). After ingesting, the median bacteria increased significantly in the control (20.06%) and the test (35.88%) (p<.001). Conclusions: After ingestion of the ENM, the number of beneficial bacteria increased and the number of harmful bacteria Clostridium tended to decrease. This suggests that ingestion of the Bacillus fermented beverage ENM has an effect on the proliferation of intestinal bacteria.

• Journal of Marine Life Science
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• v.8 no.2
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• pp.128-135
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• 2023

The present study was tried to identify whether the eel's larva was close to a conger (Conger myriaster), a pipe conger (Muraenesox cinereus) or four species of Anguilla. Experimental fishes were collected by set net in the gulf of enggang, Namhae, Korea from May to June. Their morphological characteristics were compared with adult fishes of a conger, a pipe conger and four species of Anguilla. For genetic classification, DNA was isolated and amplified by using 12S rRNA and 16S rRNA primer set. The PCR products were direct sequencing in both directions. The nucleotide sequences were analyzed using softwares. As results of morphological measurement on eel's larva, the percentages of head length and preanal length against total length were similar with a conger. Based on the nucleotide sequences, the phylogenetic tree also revealed a close relationship to a conger. Therefore, eel's larva, caught in Namhae from May to June, was identified into a conger's larva.

• Journal of Life Science
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• v.34 no.8
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• pp.576-587
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• 2024

In this study, diverse bacterial strains were isolated from fermented foods to screen those with antibacterial activity. Among them, one strain, identified as Bacillus vallismortis MCBL 1012 through 16S rRNA gene sequence analysis, was selected for its bacteriocin production. The culture supernatant of B. vallismortis MCBL 1012 showed antibacterial activity, mainly against Gram-positive bacteria. Scanning electron microscopy (SEM) revealed that bacteriocin treatment led to cellular content leakages in Listeria monocytogenes KCCM 40307, Enterococcus faecium KCCM 12118, and Streptococcus mutans KCTC 3065. PCR analysis confirmed B. vallismortis MCBL 1012 harbored subtilosin A gene (sbo A). Antibacterial activity was decreased by proteolytic enzymes like proteinase K, subtilisin A, and α-chymotrypsin. The bacteriocin demonstrated stability at 40℃ and 60℃ for 120 min, and up to 80℃ for 60 min, with rapid activity loss at 100℃. It retained full antibacterial activity within a pH range of 4.0 to 8.0 and was not affected by up to 100% organic solvents like ethanol, methanol, acetonitrile, and tetrahydrofuran. Nevertheless, activity decreased with more than 40% isopropanol and 80% acetone. Most tested inorganic salts and detergents had no effect on antibacterial activity except, CuSO₄ and NiSO₄ at specified concentrations. The bacteriocin exerted its antibacterial effect through bactericidal action against L. monocytogenes KCCM 40307. The bacteriocin was purified by ammonium sulfate precipitation, DEAE anion exchange chromatography, and RP-HPLC. The purification resulted in a final yield of 0.03% and a 283.7-fold increase in specific activity. MALDI-TOF MS analysis determined the exact molecular weight of purified bacteriocin to be 3,326.1 Da.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.549-558
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• 2007

C4B and BAT2, assigned to the SLA class III region, were recently reported on relation with human diseases. The primers for RT-PCR and RACE-PCR for CDS analysis of these genes of pig were designed by aligning the CDSs of humans and mice from GenBank. After we amplified and sequenced with these primers and cDNAs, the full-length CDSs of pig were determined. The CDS lengths of C4B and BAT2 were shown as 5226 bp and 6501 bp. In addition, the identities of nucleotide sequences with human and mouse were 76% to 87%, and the identities of amino acids were 72% to 90%. After we carried out the alignment with determined CDSs in this study and pig genomic sequences from GenBank, the primers for cSNP detection in genome were designed in intron regions that flanked one or more exons. Then, we amplified and directly sequenced with genomic DNAs of six pig breeds. Four cSNPs from C4B and three 3 cSNPs from BAT2 were identified. In addition, amino acid substitution occurred in six cSNP positions except for C4248T of C4B. By the Multiplex-ARMS method, we genotyped seven cSNPs with DNA samples used for direct sequencing. We verified that this result was the same as that analyzed using direct sequencing. To demonstrate recrudescence, we performed both direct sequencing and Multiplex-ARMS on two randomly selected DNA samples. The genotype of each sample showed the same result from both methods. Therefore, seven cSNPs were identified from C4B and BAT2 and could be used as the basic data for haplotype analysis of SLA class III region. Moreover, the Multiplex-ARMS method should be powerful for genotyping of genes assigned to the whole SLA region for the xenograft study.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.46-67
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• 1997

From 1985 to 1993, we collected 20 isolates throughout Kangwon and obtained 6 isolates from other sources. A. mellea formed rhizomorph actively, and some of A. osroyae were poor in the formation of rhizomorph and some without formation of rhizomorph. A. tabescens was active in the growth of aerial mycelium and poor in the development of rhizomorph. In A. gallica, the mycelium development among the isolates were variable greatly, and especially in isolate A8(KNU-250), the mycelial development was similar to that of A. osroyae, but A8(KNU-250) showed the feature of A. gallica to change medium into brown color. In PCR-RFLP analysis of the IGS region in rDNA, the homology between each isolate in the A. mellea and A. ostoyae showed 100% homology. A. tabescens showed $0.919{\sim}0.974$ homology, and A. gallica showed $0.619{\sim}1.000$ homology. A19 and A12 showed 100% homology as the same group, but compared with other subgroups they showed less than 10% homology as $0.051{\sim}0.108$ value. In RAPD analyses, the isolates of A. mellea showed high homology among themselves as $0.983{\sim}1.000$, and A. ostoyae also showed high similarity. The homology between isolates of A. tabescens showed $0.594{\sim}0.953$ value because A. gallica showed $0.280{\sim}0.733$ value, and the variations between isolates were greater than other species. Especially, A19 and A22 were identified as new novel group which were remoted from other groups, and the homology between these two isolates showed 0.921 value, and the genetic similarity between these groups and other 4 groups showed less than 7% as $0.012{\sim}0.069$ value. Of 5 species identified in this study, 4 species were identified as A. mellea, A. ostoyae, A. tabescens, and A. gallica that were already reported ones and 1 species was suggested as a new specie in Korea.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.111-116
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• 2012

In this study, we investigated the microbial flora changes in Gugija-Liriope tuber Makgeolli during fermentation and storage periods. We brewed Gugija-Liriope tuber Makgeolli for a week through twostage fermentations and stored the fermentation broth for a month at $4^{\circ}C$ or $20^{\circ}C$. We collected the samples periodically and analyzed microbial flora changes using viable cell counts and PCR-denaturing gradient gel electrophoresis (DGGE). Yeast viable cells were seen to have decreased to 13% of pre-storage levels after storage for 15 days at $20^{\circ}C$; however significant changes were not observed during storage at $4^{\circ}C$. Prolongation of storage time dramatically decreased the availability of viable cells. Yeast viable cell numbers had decreased to 38% of pre-storage levels at $4^{\circ}C$ and 4.8% at $20^{\circ}C$ after storage for 30 days. The results of the DGGE profile for yeast showed that Saccharomyces cerevisiae and Saccharomyces sp. were the predominant strains at the beginning of fermentation and throughout the whole period of storage. Viable cell counts for total bacteria had decreased to 36% of pre-storage levels after storage for 15 days but did not significantly change for the full 30 days of storage at $4^{\circ}C$. Similarly, viable cell counts for bacteria had decreased to 5% while viable cell numbers did not significantly change for the full 30 days at $20^{\circ}C$. Viable cell counts for lactic acid bacteria were performed and the results were similar to those for total bacteria. The results of the DGGE profile for bacteria showed that Weissella cibaria was the predominant strain at the beginning of fermentation. However it had disappeared by the end of fermentation, and Lactobacillus fermentum and Pediococcus acidilactici became the predominant species during storage.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.298-308
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• 2009

A flexuous rod-shaped virus was isolated from Cucurbita pepo leaves showing as green mosaic and puckering symptoms at Anseong, Korea. Based on the biological analysis, electron microscopy, and reverse transcription-polymerase chain reaction (RT-PCR), the virus isolate was identified as Papaya ringspot virus type watermelon (PRSV-W). From biological analysis, the host range of PRSV-W was limited to the families Cucurbitaceae and Chenopodiaceae. Most susceptible cucurbit species, such as Cucumis lanatus, Cucumis sativus, Cucurbita pepo, and Citrullus lanatus, showed symptoms of green mosaic, malformation, puckering, and narrow laminae by infection with PRSV-W. The local lesion were showed on the inoculated leaves of both Chenopodium amaranticolor and C. quinoa. Field survey of PRSV, Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV), three major viruses infecting cucurbit, was done during 2001 to 2003 on 173 commercial cucurbit cultivating fields distributed over the three regions of Gyeonggi, Gyeongbuk and Jeonnam Provinces where cucurbits are grown in different environmental conditions and cropping patterns. Typical viral symptoms were observed from 107 cultivating fields, and all three kinds of potyviruses were detected from 206 samples out of the 235 samples using RT-PCR. Watermelon mosaic virus (WMV) and Zucchini yellow mosaic virus (ZYMV) are the most widely distributed viruses in outdoor and retarding-culture fields, at an infection rating of 48 and 33 percents, respectively. PRSV was detected from 12 percent of 235 samples. The nucleotide and amino acid sequences of coat proteins (CP) of eight PRSV isolates, collected from several areas including Anseong, were determined and sequenced heterogeneity among the isolates was performed. The CP gene of PRSV showed 88.6~97.3 percent homology in nucleotide sequences and 95.1~99.3 percent homology in amino acid sequences with other PRSV isolates worldwide. The phylogenetic analysis indicated that the Korean PRSV isolates belong to the southern-east Asian cluster.