• Research in Plant Disease
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• v.20 no.1
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• pp.25-30
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• 2014

Phytophthora infestans was isolated from potato leaves collected from main potato producing areas in Korea during 2009-2011. In 2009, 99 isolates tested were all A1 mating type. Two of 64 isolates in 2010 and two of 78 isolates in 2011 were A2 mating type and they were found only in Miryang area. Among 99 isolates examined in 2009, 13.1% was resistant to metalaxyl, 3.1% was intermediate resistant and 83.8% was sensitive. In 2010, 19.4% of 62 isolates was resistant, 4.8% was intermediate and 75.8% was sensitive. Metalaxyl resistant, intermediate and sensitive isolates collected in 2011 were 23.1%, 9.0% and 67.9%, respectively. Metalaxyl resistant isolates increased mainly in winter cropping areas and seed potato producing areas where fungicides were sprayed more often. Frequencies of isolates showing minimum inhibition concentration of dimethomorph at $1.0-5.0{\mu}g/ml$ were 17.2% in 2009, 19.0% in 2010 and 15.4% in 2011. However, there was no evidence for occurrence of resistant isolate to dimethomorph because no isolate was able to grow at $5.0{\mu}g/ml$.

• Research in Plant Disease
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• v.18 no.2
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• pp.93-100
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• 2012

Resistance of pepper (Capsicum spp.) to anthracnose (Colletotrichum acutatum) was evaluated during regeneration of Capsicum spp. in National Agrobiodiversity Center. Disease severity of 896 pepper accessions (430 accessions of C. annuum, 219 accessions of C. baccatum, 14 accessions of C. chacoense, 153 accessions of C. chinense, 70 accessions of C. frutescens, 2 accessions of C. pubescens, and unidentified 8 accessions) was investigated at 14 days after inoculation in $28^{\circ}C$ humid chamber. Forty nine accessions of pepper germplasm were resistant to C. acutatum. Among them, nine accessions were highly resistant to C. acutatum without wounding spray inoculation. Four accessions belonged to the species C. baccatum, one accession to C. chacoense, and four accessions to C. frutescens. Forty two resistant candidate accessions were inoculated with pin-prick wounding using a syringe needle. Five accessions were resistant as a less than 3% of disease severity to C. acutatum with wounding inoculation 5 days after inoculation. All resistant accessions were C. baccatum. These five pepper germplasm might be used as breeding resources for the anthracnose resistance breeding program.

• Archives of Pharmacal Research
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• v.11 no.3
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• pp.218-224
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• 1988

The preparation of Clostridium butyricum is used as a normalizing agent for human intestinal flora. When the microbe is simultaneously used with rifampicin, it is inactivated by the antibiotic. To develop rifampicin-resistant mutants, rifampicin-sensitive strain Miyairi II 588 of C. butyricum was treated with nitrosoguanidine (NTG). To ensure stable resistance to rifampicin, we examined whether the resistance was plasmid-mediated or chromosome-mediated. It was found that the resistance of four mutant strains was not mediated by its inherent plasmid, but by the chromosomal mutation. These strains were examined for the susceptibility and resistance to other antituberculosis agents and antibiotics. The results showed that these mutants were resistant to the high concentration of the antituberculosis agents.

• The Journal of the Korean life insurance medical association
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• v.28 no.1_2
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• pp.15-18
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• 2009

Background: Recent emergence of drug-resistant tuberculosis such as multidrug-resistant tuberculosis(MDR-TB) or extensively drug-resistant tuberculosis(XDR-TB) has become important health care problems. It has also became grave issues for insurance industries in determining medical risks. We have therefore strived to analyze the comparative mortality rates for drug-resistant tuberculosis through utilization of results from previous articles. Methods: Comparative mortality was calculated from source articles using mortality analysis methods. Results: Mortality ratio of MDR-TB was estimate to 1200%, and excess death rate was 110 per 1,000. Comparative mortality between MDR-TB and XDR-TB by Korean $study^{(1)}$ were 1750, 382, 405, 443, 1025, and 357%, for each 10 months study intervals, respectively. Total mortality ratio was 594% and total excess death rate was 60 per 1,000person. It was determined that the risk of XDR-TB was much greater than MDR-TB. Discussion; Pending the development of a novel anti-tuberculosis drug, it would be prudent to steer clear insuring XDR-TB during underwriting phase due to high medical cost that it creates.

• Childhood Kidney Diseases
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• v.3 no.2
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• pp.237-240
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• 1999

The presence of polyostotic fibrous dysplasia of bone, hyperpigmented skin macules, and precocious sexual development in children is known as the McCune-Albright syndrome. In addition to the described in McCune-Albright syndrome, other endocrinopathies have been reported including hyperthyroidism, acromegaly, Cushing syndrome and vitamin D resistant rickets. The case describes a 6-year-old boy showing bony deformities due to polyostotic fibrous dysplasia, hyperpigmented skin macules, hyperthyroidism and vitamin D resistant rickets. The purpose of this report is to describe a patient of McCune-Albright syndrome with vitamin D resistant rickets which is very rare.

• Journal of Biosystems Engineering
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• v.40 no.2
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• pp.110-114
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• 2015

Purpose: A threshing machine for shatter-resistant sesame was designed and developed in this study. Methods: Two types of sesame (shatter-resistant and conventional) were tested using the developed sesame threshing system. Three types of serrated bars were designed and evaluated through performance tests, in terms of the ratio of unthreshed sesame. Results: In the case of conventional sesame, the ratio of unthreshed sesame did not show any difference with bar type or cylinder rotation speed. For shatter-resistant sesame, however, the ratio of unthreshed sesame decreased with increased cylinder rotating speed for all three types of bar. Conclusions: These results are useful for the construction and utilization of an efficient threshing harvester. The type-L bar showed the best result in the energy equation.

• YAKHAK HOEJI
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• v.37 no.4
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• pp.350-355
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• 1993

The preparation of Streptococcus faecalis RSI is used as a medicinal preparation for human intestinal disorders. But the microbe in this preparation is very sensitive to rifampicin. If this preparation is taken with rifampicin, its therapeutic effect can not be expected. To develope rifampicin resistant mutants, the rifampicin sensitive strain S. faecalis RSI was treated with Nmethyl-N'-nitro-N-nitrosoguanidine(MNNG). Twelve strains of the MNNG-induced mutants showed distinct resistance to rifampicin and five mutants were selected for further studies. They also exhibited identical characteristics with the parent S. faecalis RSI when they were tested for lactic acid formation and growth inhibition of E. coli. From in vitro test, it was identified that rifampicin is not inactivated by certain factors of the rifampicin resistant mutants. Conclusively, the rifampicin resistant mutants are efficient strains that have insensitivity against rifampicin and original biochemical characteristics of the parent strain.

• Molecules and Cells
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• v.25 no.3
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• pp.407-416
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• 2008

Thirteen near-isogenic lines (NILs) of japonica rice were developed via a backcross method using the recurrent parent Chucheong, which is of good eating quality but is susceptible to Magnaporthe grisea, and three blast resistant japonica donors, Seolak, Daeseong and Bongkwang. The agro-morphological traits of these NILs, such as heading date, culm length, and panicle length, were similar to those of Chucheong. In a genome-wide scan using 158 SSR markers, chromosome segments of Chucheong were identified in most polymorphic regions of the 13 NIL plants, and only a few chromosome segments were found to have been substituted by donor alleles. The genetic similarities of the 13 NILs to the recurrent parent Chucheong averaged 0.961, with a range of 0.932-0.984. Analysis of 13 major blast resistance (R) genes in these lines using specific DNA markers showed that each NIL appeared to contain some combination of the four R genes, Pib, Pii, Pik-m and Pita-2, with the first three genes being present in each line. Screening of nine M. grisea isolates revealed that one NIL M7 was resistant to all nine isolates; the remaining NILs were each resistant to between three and seven isolates, except for NIL M106, which was resistant to only two isolates. In a blast nursery experiment, all the NILs proved to be more resistant than Chucheong. These newly developed NILs have potential as commercial rice varieties because of their increased resistance to M. grisea combined with the desirable agronomic traits of Chucheong. They also provide material for studying the genetic basis of blast resistance.

• The Plant Pathology Journal
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• v.22 no.4
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• pp.369-374
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• 2006

To characterize benzimidazole-resistant and -sensitive Monilinia fructicola populations, the fungal isolates were obtained from peach plants showing brown rot and bloosom blight. Benzimidazole-sensitive isolates did not grow on potato dextrose agar(PDA) amended with $\geq1.0{\mu}g$ active ingredient(a.i.)/ml of the fungicides. However, benzimidazole-resistant isolates grew on PDA regardless of the tested concentrations of fungicides. Benzimidazole-resistant isolates did not grow on diethofencarb-PDA, but sensitive isolates grew on the same PDA. In the nucleotide sequences of $\beta$-tubulin gene, only codon 198(GAG: glutamic acid), a target site for benzimidazole, was replaced with GCG(alanine) in all of the resistant isolates, and this substitution seems to play an important role in the development of resistance. Other interesting codons such as 165(GCT), 200(TTC), and 241(GCT) were not changed among the isolates. Benzimidazole-resistant and -sensitive isolates were clustered clearly in random amplified polymerphic DNA analyses and the results revealed that low levels of genetic diversity between benzimidazole-sensitive and -resistant isolates of M. fructicola in the investigated regions.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1620-1628
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• 2016

In this study, we investigated colistin resistance mechanisms associated with the regulation of the pbgP operon in Klebsiella pneumoniae, using four isogenic pairs of colistin-susceptible strains and their colistin-resistant derivatives and two colistin-resistant clinical isolates. Amino acid sequence alterations of PhoPQ, PmrAB, and MgrB were investigated, and mRNA expression levels of phoQ, pmrB, pmrD, and pbgP were measured using quantitative real-time PCR. The phoQ and pmrB genes were deleted from two colistin-resistant derivatives, 134R and 063R. We found that phoQ, pmrD, and pbgP were significantly upregulated in all colistin-resistant derivatives. However, pmrB was significantly upregulated in only two colistin-resistant derivatives and one clinical strain. pmrB was not overexpressed in the other strains. The minimum inhibitory concentration of colistin was drastically lower in both phoQ- and pmrB-deleted mutants from a colistin-resistant derivative (134R) that was overexpressing phoQ and pmrB. However, colistin susceptibility was restored only in a phoQ-deleted mutant from a colistin-resistant derivative (063R) without overexpression of pmrB. In conclusion, two different regulations of the pbgP operon may associate with the development of colistinresisant K. pneumoniae.