• Research in Plant Disease
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• v.29 no.1
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• pp.79-81
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• 2023

During the nationwide survey of fire blight, the typical shoot blight symptoms were found on Korean mountain ash (Sorbus alnifolia) which was located near an orchard that produced fire blight on pear trees in Eumseong, Korea, May 2021. To identify the causal agent, we progressed isolation from the symptomatic leaves and shoots. Two white and mucoid colonies were isolated into the pure culture. Two isolates were identified as Erwinia amylovora according to the colony-polymerase chain reaction (PCR) with amsB primers and the phylogenetic tree using 16S rRNA sequences. To test of pathogenicity of two isolates, we inoculated immature pear fruits and understock of apple. We observed necrosis and oozes on immature pear fruits and shoot blight resulting in necrosis on apple shoots six days after inoculation. Colonies were recovered from the inoculated pears and apples, and identity was confirmed through colony PCR for amsB genes. To our knowledge, E. amylovora was first reported on Korean mountain ash native to South Korea.

• Biomedical Science Letters
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• v.2 no.1
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• pp.49-55
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• 1996

The objective of this study was to develop a paper strip which could determine E. coli qualitatively and quantitatively in water, wastewater, drinks, or food. This paper strip method was a simple and rapid test method that determine E. coli by visual identification. In this study, nutrient culture media were formulated and characterized for optimum conditions. Paper strips were then prepared by impregnating into the media and dried at $60^\circ$C. The test procedure is quite simple to use. The paper strip was dipped into a sample, and excess sample was removed. The strip was then incubated at $37^\circ$C for 16 to 20 hours and the number of colonies on the strip was counted. The color of the colony spots produced by microorganisms varied depending on the media formulation. Violet-red spots were produced by E. coli. The test method was simple, rapid and no special laboratory equipment was necessary for visual identification. Therefore, this test method is applicable to on-site tests such as field tests or home tests. The paper strip method was compared with the standard agar plate method and Japanese commercial product. The method of the economical preparation of test strips was studied for production on industrial scale.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.1
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• pp.45-53
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• 2006

Anaerobic black-pigmented bacteria have been implicated in the endodontic infections. This group of microorganisms includes Porphyromonas endodontalis, P. gingivalis, Prevotella intermedia, and Prevotella nigrescens. The organisms display a wide variety of virulence factors that may be pertinent to acute endodontic infections. The aim of this study was to identify P. endodontalis, P. gingivalis, P. intermedia, and P. nigrescens by using the special potency disk test, filter paper spot test, 16S rRNA gene-directed PCR, and API 32A system. Microbial samples were collected from root canals of 33 intact teeth with necrotic pulp and apical periodontitis. Conventional laboratory methods were used to identify the strains of anaerobic black pigmented bacteria. Eighteen out of 33 samples were positive for the growth of black-pigmented bacrteria. Five colonies were cultured from each pure cultured colony from Brucella agar plates. Seventy seven colonies were positive for the growth of black-pigmented bacteria. Thirty three out of 77(42.8%) were identifed as P. nigrescens, 10 out of 77(13%)were P. gingivalis, 6 out of 77(7.8%) were P. endodontalis, 10 out of 77(13%) were P. intermedia. On the contrary the reference strains of P. nigrescens, experimental strains of P. nigrescens were susceptible to kanamycin in the special potency disk test. We concluded that after rapid presumptive identification methods, such as the special potency disk test and filter paper spot test were done, 16S rRNA gene PCR and API 32A test would be accurate detection methods for black-pigemented bacteria.

• Archives of Pharmacal Research
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• v.19 no.4
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• pp.261-263
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• 1996

SK-302B, an antibiotic purified from soil Streptomyces sp. 302, was structurally identified as echinomycin (C/sub 50/H/sub 66/N/sub 11/S/sub 2/). In the present experiment, the possibility of SK-302B as an anticolon cancer agent was investigated by using chemosensitivity system (MTT assay, clonogenic assay). Treatment of SK-302B on various colon cancer cell lines resulted in a significant cytotoxicity and tumor colony formation inhibition. These studies showed that SK-302B had a potent inhibition on colon cancer cells.

• Journal of Veterinary Clinics
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• v.25 no.3
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• pp.211-214
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• 2008

This report describes a case of severe and prolonged dermatophytosis in a hedgehog that was diagnosed by PCR-RFLP, a rapid and usefulness technique for identification of many causative agents and hereditary characters. A 5-month-old female hedgehog was presented with grade 2 facial pruritus, scaling, encrustation and hemorrhage. Cytology of exudates on the face showed a suspected fungal infection. A culture and tape imprint test of the cultured colony showed many hyphae and microcornidia, suspected to belong to the Trichophyton species. In the PCR-RFLP with MvaI and Hinf I, Trichophyton mentagrophytes var. erinacei was finally identified as a causative agent. The patient completely recovered after application of nystatin cream for 17 days.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.38-42
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• 1997

For the purpose of obtaining microorganisms producing high amount of erythritol, the screening test was carried out. Productivity of erythritol was analyzed by paper chromatography and HPLC' methods. Among more than two hundred isolates, one strain(KJX1) was selected as an erythritol prtducer from thc soil of corn shock. The isolated strain was identified as Pmicilliurn sp. KJ81 from the morphological and physiological characteristics. Penicillium sp. KJ81 showed white to green colony color, two- to three-stage branching conidiophcvc and flask-shaped phialides.

• Textile Coloration and Finishing
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• v.10 no.6
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• pp.49-54
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• 1998

The antimicrobial activities of the copolymer of N,N'-dimethyl-N,N'-diallyl ammonium chloride (DMDAAC) and acrylamide(AA) were investigated. A series of copolymers with various ratios of DMDAAC and AA were prepared by free radical initiation via an intra-intermolecular propagation mechanism, ie, cyclopolymerization, and the antimicrobial activities of the prepared copolymers were measured by minimum inhibitory concentration(MIC) test. The copolymers were, then, methylolated under basic condition for reactivity with hydroxyl group of cellulose. Both antimicrobial activity and fastness to laundering of the cotton fabrics finished using the methylolated copolymers were evaluated. From the results it was shown that the copolymers with different ratios of DMDAAC and AA have MIC values in the range of 1∼100ppm. As the ratio of AA in the copolymers increases, the anitmicrobial activity decreases. The fastness of the cotton fabric finished by the methyolated copolymers to 10 repeated launderings in anionic commercial detergent is good enough to show colony reduction above 90％ regardless of DMDAAC and AA ratios.

• Environmental Mutagens and Carcinogens
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• v.16 no.2
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• pp.117-123
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• 1996

This study was carried out to examine the mechanism of Arsenic cytotoxicity through several in vitro test systems. Dose-dependent decrease of cell survival by Arsenic was observed by colony forming assay. Arsenic was weak mutagenic in inducing HGPRT point mutation in CHO cells. The frequency of chromosomal aberrations increased in a dose-dependent manner and the most frequent type of chromosomal aberrations induced by Arsenic were chromatid type deletions. U!trafiltrates of culture media from CHO cells treated with Arsenic induced sister chromatid exchanges(SCE) in CHO cells and Arsenic was able to induce lipid peroxidation in CHO cells. The results suggested that the ultrafiltrates of media from CHO cells treated with Arsenic contain clastogenic factor(CF) and Iipid peroxidation might be involved in the formation of CF.

• Journal of Ginseng Research
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• v.20 no.1
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• pp.15-22
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• 1996

In order to investigate the Immunomodulatory effects of ginseng, we have studied the effects of ginseng saponin on the proliferation and cytosine gene expression of human pheripheral blood mononuclear cell (PBMC). In the PBMC proliferation assay, total saponin exhibited proliferation inhibition on the PBMC or phytohemagglutinin(PHA)-stimulated PBMC in a dose-dependent fashion. Immunomodulatory effects of ginseng were further investigated using the cytokine gene expression as the indicators. In the reverse transcription-polymerase chain reaction (RT-PCR) test, interleukin (IL)-1, IL-2, IL-3, IL-4, IL-6, IL-13, granulocyte macrophage-colony stimulating factor, tumor necrosis factor (TNF), migration inhibitory factor and transforming growth factor genes were expressed in the PHA-stimulated PBMC 48 hrs after cell culture. Among expressed cytokines, total saponin could increase the expression of IL-1 and TNF of PBMC without stimulation of PHA. All of ginsenosides, $Rb_1$, $Rb_2$, $Rg_1$, Rc, Re, incresed TNF gene expression. Especially, Rb2 (20 g/ml) showed most prominent effect on TNF gene expression and it also slightly increased IL-1 gene expression of PBMC.

• Biomolecules & Therapeutics
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• v.10 no.3
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• pp.170-174
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• 2002

The local irritation study (skin and occular irritation tests) of HM10411, a rhG-CSF (recombinant human granulocyte-colony stimulating factor) was carried out in New Zealand White rabbits. HM10411 was applied to the bare skin at a dose of 2.5 mg/rabbit (5.0 mg/ml, 0.5 ml) and to the conjunctival sac of eye at a dose of 0.5 mg/rabbit (5.0 mg/ml, 0.1 ml) , respectively. In this study, there were no clinical signs which were related to HM10411 compared with those of control group. From above results, HM10411 has not any irritating activity to skin and eye in rabbits.