• Natural Product Sciences
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• 제28권3호
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• pp.93-104
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• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to the global healthcare system. Ineffective and resistance to antibiotic treatments have increased morbidity and mortality rates worldwide. New and effective antibiotics are needed to combat against bacterial resistance. Endophytic fungi are crucial reservoirs of novel bioactive metabolites. In particular, the secondary metabolites show promising therapeutic potential, notably, antibacterial. This review discussed the emerging potential of endophytic fungi as anti-MRSA agents. The ecological sources of endophytic fungi were discussed with the synthesis of bioactive metabolites. The mode of antibacterial actions was elucidated to give a better understanding of the mechanisms involved. This review may serve as an important reference for future discovery and developments of anti-MRSA agents from endophytic fungi.

• 식물병연구
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• 제17권3호
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• pp.326-333
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• 2011

Ralstonia solanacearum에 의해 발생하는 토마토 풋마름병에 대하여 저항성으로 알려진 토마토 순계 품종의 국내 병원균에 대한 저항성 반응을 온도별로 평가하였다. 한국에서 분리된 R. solanacearum 균주로 토마토 순계 6 품종의 저항성을 평가한 결과 기존에 저항성으로 알려진 토마토 순계들이 한국 분리균주에 대하여는 대부분 저항성을 유지하지 못하였다. 병원성이 강한 균주인 SL341 (race 1, biovar 4) 균주는 검정한 대부분의 품종에서 온도에 관계없이 강한 병원성을 보였다. 반면, 담배에서 분리된 균주인 SL1944(race 1, biovar 4)은 온도에 따라 발병진전이 현저하게 차이가 났다. Moneymaker와 Bonny Best와 같은 품종은 온도에 관계없이 SL1944에 대하여 감수성이었다. 그러나, 풋마름병 저항성 품종으로 알려진 Hawaii 7998, Hawaii 7996, B-blocking 품종은 오히려 상대적으로 고온인 조건($35^{\circ}C$에서 14시간 명조건과 $28^{\circ}C$에서 10시간 암조건)에서 급격히 발병하였다. 병 진전은 동일한 품종의 낮은 온도에서 병 진전이나 Moneymaker나 Bonny Best 같은 품종에서 동일한 고온 조건의 발병에 비해 눈에 띄게 빨랐다. 본 연구결과는 국내에서 분리된 균주들이 기존에 저항성 토마토 품종을 가해할 수 있으며 고온조건에서는 품종의 저항성 붕괴의 가능성으로 급격한 풋마름병이 유발될 수 있음을 제시한다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.73-73
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• 2018

Bacterial leaf blight(BLB), caused by X. oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice due to its high epidemic potential. Understanding BLB resistance at a genetic level is important to further improve the rice breeding that provides one of the best approaches to control BLB disease. In the present investigation, a collection of 192 accessions was used in the genome-wide association study (GWAS) for BLB resistance loci against four Korean races of Xoo that were represented by the prevailing BLB isolates under Xoo differential system. A total of 192 accessions of rice germplasm were selected on the basis of the bioassay using four isolated races of Xoo such as K1, K2, K3 and K3a. The selected accessions was used to prepare 384-plex genotyping by sequencing (GBS) libraries and Illumina HiSeq 2000 paired- end read was used for GBS sequencing. GWAS was conducted using T ASSEL 5.0. The T ASSEL program uses a mixed linear model (MLM). T he results of the bioassay using a selected set of 192 accessions showed that a large number of accessions (93.75%) were resistant to K1 race, while the least number of accessions (34.37%) resisted K3a race. For races K2 and K3, the resistant germplasm proportion remained between 66.67 to 70.83%. T he genotypic data produced SNP matrix for a total of 293,379 SNPs. After imputation the missing data was removed, which exhibited 34,724 SNPs for association analysis. GWAS results showed strong signals of association at a threshold of [-log10(P-value)] more than5 (K1 and K2) and more than4 (K3 and K3a) for nine of the 39 SNPs, which are plausible candidate loci of resistance genes. T hese SNP loci were positioned on rice chromosome 2, 9, and 11 for K1 and K2 races, whereas on chromosome 4, 6, 11, and 12 for K3 and K3a races. The significant loci detected have also been illustrated, NBS-LRR type disease resistance protein, SNARE domain containing protein, Histone deacetylase 19, NADP-dependent oxidoreductase, and other expressed and unknown proteins. Our results provide a better understanding of the distribution of genetic variation of BLB resistance to Korean pathogen races and breeding of resistant rice.

• 한방재활의학과학회지
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• 제25권2호
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• pp.1-13
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• 2015

Objectives Methicillin-Resistant Staphylococcus aureus (MRSA) is a human pathogen and a major cause of hospital-acquired infections. New antibacterial agents that have not been compromised by bacterial resistance are needed to treat MRSA-related infections. In this study, we investigated the antimicrobial activity ofethanol extract of Haedokgeumhwa-san (HGH) which prescription is composed of korean medicine against MRSA. Methods The antibacterial activity of HGH extract was evaluated against MRSA strains by using the Disc diffusion method, broth microdilution method (minimal inhibitory concentration; MIC), checkerboard dilution test, and time-kill test; its mechanism of action was investigated by bacteriolysis, detergent or ATPase inhibitors. The checkerboard dilution test was used to examined synergistic effect of ampicillin, oxacillin, ciprofloxacin, vancomycin, gentamicin and norfloxacin in combination with HGH ethanol extract. A time-kill assay was performed a survival curve which was obtained by plotting viable colony counts depending on time on bacterial growth. Results The minimum inhibitory concentration (MIC) of ethanol extract (HGH) ranged from 1,000 to $2,000{\mu}g/mL$ against all the tested bacterial strains, respectively. We are able to confirm that HGH extract has potentially strong antibacterial activity. In the checkerboard dilution test, fractional inhibitory concentration index of HGH in combination with antibiotics indicated synergy or partial synergism against S. aureus. A time-kill study showed that the growth of the tested bacteria was considerably inhibited after 8 hr of treatment with the combination of HGH with selected antibiotics. For measurement of cell membrane permeability, HGH $250{\sim}1,000{\mu}g/mL$ along with concentration of Triton X-100 (TX) and Tris-(hydroxymethyl) aminomethane (Tris) were used. In the other hand, N,N-dicyclohexylcarbodimide (DCCD) and Sodium azide ($NaN_3$) was used as an inhibitor of ATPase. TX, Tris, DCCD and $NaN_3$ cooperation against S. aureus showed synergistic action. Accordingly, antimicrobial activity of HGH was affected by cell membrane and inhibitor of ATPase. Conclusions These results suggest that Haedokgeumhwa-san extract has antibacterial activity, and that HGH extract offers a potential as a natural antibiotic against MRSA.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.62-62
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• 2019

Bacterial leaf blight(BLB), caused by X. oryzae pv. oryzae(Xoo), is one of the most destructive diseases of rice due to its high epidemic potential. Understanding BLB resistance at a genetic level is important to further improve the rice breeding that provides one of the best approaches to control BLB disease. In the present investigation, a collection of 192 accessions was used in the genome-wide association study (GWAS) for BLB resistance loci against four Korean races of Xoo that were represented by the prevailing BLB isolates under Xoo differential system. A total of 192 accessions of rice germplasm were selected on the basis of the bioassay using four isolated races of Xoo such as K1 and K2. The selected accessions was used to prepare 384-plex genotyping by sequencing (GBS) libraries and Illumina HiSeq 2000 pairedend read was used for GBS sequencing. GWAS was conducted using TASSEL 5.0. The TASSEL program uses a mixed linear model (MLM). The results of the bioassay using a selected set of 192 accessions showed that a large number of accessions (93.75%) were resistant to K1 race and K2 resistant germplasm proportion remained between 66.67. The genotypic data produced SNP matrix for a total of 293,379 SNPs. After imputation the missing data was removed, which exhibited 34,724 SNPs for association analysis. GWAS results showed strong signals of association at a threshold of [-log10(P-value)] more than 5 (K1 and K2) for nine of the 39 SNPs, which are plausible candidate loci of resistance genes. These SNP loci were positioned on rice chromosome 2, 9, and 11 for K1 and K2 races. The significant loci detected have also been illustrated and make the CPAS markers for NBS-LRR type disease resistance protein, SNARE domain containing protein, Histone deacetylase 19, NADP-dependent oxidoreductase, and other expressed and unknown proteins. Our results provide a better understanding of the distribution of genetic variation of BLB resistance to Korean pathogen races and breeding of resistant rice.

• Animal Bioscience
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• 제35권11호
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• pp.1698-1710
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• 2022

Objective: Raw potato starch (RPS) is resistant to digestion, escapes absorption, and is metabolized by intestinal microflora in the large intestine and acts as their energy source. In this study, we compared the effect of different concentrations of RPS on the intestinal bacterial community of weaned piglets. Methods: Male weaned piglets (25-days-old, 7.03±0.49 kg) were either fed a corn/soybean-based control diet (CON, n = 6) or two treatment diets supplemented with 5% RPS (RPS5, n = 4) or 10% RPS (RPS10, n = 4) for 20 days and their fecal samples were collected. The day 0 and 20 samples were analyzed using a 16S rRNA gene sequencing technology, followed by total genomic DNA extraction, library construction, and high-throughput sequencing. After statistical analysis, five phyla and 45 genera accounting for over 0.5% of the reads in any of the three groups were further analyzed. Furthermore, short-chain fatty acids (SCFAs) in the day 20 fecal samples were analyzed using gas chromatography. Results: Significant changes were not observed in the bacterial composition at the phylum level even after 20 d post feeding (dpf); however, the abundance of Intestinimonas and Barnesiella decreased in both RPS treatment groups compared to the CON group. Consumption of 5% RPS increased the abundance of Roseburia (p<0.05) and decreased the abundance of Clostridium (p<0.01) and Mediterraneibacter (p< 0.05). In contrast, consumption of 10% RPS increased the abundance of Olsenella (p<0.05) and decreased the abundance of Campylobacter (p<0.05), Kineothrix (p<0.05), Paraprevotella (p<0.05), and Vallitalea (p<0.05). Additionally, acetate (p<0.01), butyrate (p<0.05), valerate (p = 0.01), and total SCFAs (p = 0.01) were upregulated in the RPS5 treatment group Conclusion: Feeding 5% RPS altered bacterial community composition and promoted gut health in weaned piglets. Thus, resistant starch as a feed additive may prevent diarrhea in piglets during weaning.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.266-266
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• 2022

The outbreaks of blast, bacterial blight and viral diseases have been increasing in early maturing rice cultivating areas in the central northern regions, recently. As the occurrence of sudden insects pests and disasters increases due to global climate warming, it is urgent to develop a variety of disaster-tolerant, high-quality varieties in response. This study was carried out to elucidate the characteristics of early-maturing, high-quality and multiple disease resistant rice variety, Cheolweon109 that was adapted to cultivation in the mid-mountainous regions of the central northern regions. Cheolweon109 was derived from a cross between Suweon546, medium maturing variety, and Sangju44 which is early maturing and resistant to blast, bacterial blight and rice stripe virus. The heading date of Cheolweon109 was July 30, 3 days later than Odae. The culm length of Cheolweon109 was 79 cm, which was about 5 cm taller than Odae, and the ripening ratio was 85.1%, which was 10% higher than that of Odae. This variety had 5.54 MT/ha of milled rice productivity, which was 99% of the Odae. Although Cheolweon109 was tall, it was strong against lodging. It was strong against bacterial blight (K1, K2, K3 race), rice stripe virus, and the pre-harvest sprouting which rate was 2.4%. The appearance of the grains of rice was clean, the glossiness was 70.6, and the head rice ratio was 95.3% high. Because Cheolweon109 had superior disease resistance, disaster resistance, and high quality than Odae, it was expected that can be used to expand the diversity of early maturing and high-quality rice varieties in central northern regions.

• Journal of Plant Biotechnology
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• 제33권4호
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• pp.309-313
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• 2006

본 연구는 흰잎마름병 K1 레이스에 감수성인 상주찰벼와 저항성인 HR13721-53-3-1-3-3-2-2를 인공교배하여 육성된 F2, F3를 재료로 하천 Kl 레이스에 대한 저항성 검정과 SNP 마커를 이용한 유전자형 분석 및 저항성과의 연관성을 분석하였다. Kl 레이스에 대한 저항성 검정 결과 $F_2,\;F_3$에서 각각 이론적 분리비인 3:1, 1:1의 분리비를 나타냈으며 SNP 마커를 이용한 유전자형 분석은 16PFXa1 primer를 이용하여 유전자를 증폭한 후 Eco RV 제한효소 처리하여 다형성을 분석하여 저항성 및 유전자형을 확인할 수 있었다. K1 레이스에 대한 저항성 검정과SNP마커를 이용한 유전자형의 연관분석 결과 저항성과 마커간에 연관성이 일치하였으며, 특히 SNP 마커를 이용한 유전자형 분석에서는 K1 레이스에 대한 저항성 검정에서 알 수 없었던 $F_2$ 개체가 동형접합체인지 이형접합체인지를 판별할 수 있어 저항성 품종 육종을 위한 선발 효율을 높일 수 있었다.

• 식물병연구
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• 제25권3호
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• pp.108-113
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• 2019

북한의 작물 생산성은 남한에 비하여 월등히 낮다. 이러한 이유 중 하나는 취약한 병 관리에 있다. 북한은 농경지의 약 30%가 논으로 이루어져 있다. 벼 도열병과 벼 흰잎마름병은 북한 벼 재배 시 각각 가장 중요한 곰팡이 병 및 세균 병이다. 본 연구에서는 벼 도열병균과 벼 흰잎마름병균에 대한 7개 북한 벼 품종의 병 저항성 반응을 시험하였다. 남한에서 분리한 18개 벼 도열병균에 대한 7개 벼 품종의 반응은 다소 다르게 나타났다. 7개 벼 품종 중 길주1호는 KI 혹은 KJ 레이스에 관계없이 남한에서 분리한 벼 도열병균 18개 균주 모두에 매우 저항성을 보였다. 평도5호는 남한에서 분리한 벼 도열병균 15개 균주에 대하여 감수성 반응을 보였다. 반면, 벼 흰잎마름병균에 대한 북한 벼 품종의 병 저항성 반응은 벼 도열병균에 대한 반응과 차이를 보였다. 길주1호는 K1 레이스인 KXO42와 K2 레이스인 KXO90에 대하여 높은 감수성을 보였고, 평도5호는 K1 레이스인 KXO85와 K3 레이스인 KXO19에 완전한 저항성을 보였다. 평양21호는 K1 레이스 모두에 완전한 저항성을 보였고, 원산69호는 KXO85를 제외한 모든 벼 흰잎마름병균에 감수성을 보였다. 이 연구는 향후 남북 농업 협력을 통하여 북한 벼 품종을 남한에 도입 시 두 병원균에 대한 북한 벼 품종의 저항성 반응 검정 및 벼 품종 육성에 중요한 기본 자료가 될 것이다.

• Journal of Chest Surgery
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• 제26권10호
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• pp.801-803
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• 1993

Surgical correction of patent ductus arteriosus is,under most circumstances,highly successful and carries a low mortality. But infected PDA is yet potentially dangerous due to its frequent recurrence and resistant organisms to antibiotics. And,in surgical correction,surgeon may face the possibility of tearing of ductus arteriosus arterial end due to friability and adhesion of its surrounding tissue.This report demonstrats another problem in treatment of infected patent ductus arteriosus.This thirteen years old female patient received susceptible combined antibiotics intravenously from the day of admission and remitted from 4th.week of therapy.This remission state continued for 12days without relapse.But the pulmonary artery ruptured in this remission period.In autopsy,bacteria was not found in ductal vegetation.Also,there was no pulmonary artery aneurysm,Our experience show that in infected PDA,pulmonary artery can rupture spontaneously during remission period without aneurysmal formation.