• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.619-627
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• 2001

n order to increase the virus safety of a human intravenous immunoglobulin (IVIg) that was manufactured by a successive process of cold ethanol fractionation, polyethylene glycol precipitation, and pasteurization ($60^{\circ}C$ heat treatment for 10h), a low pH incubation process (pH 3.9 at $25{\circ}C$ for 14 days) was employed as the final step. The efficacy and mechanism of the fraction III cold ethanol fractionation, pasteurization, and low pH treatment steps in the removal and/or inactivation of blood-borne viruses were closely examined. A variety of experimental model viruses for human pathogenic viruses, including the Bovine herpes virus (BHV), Bovine viral diarrhoea virus (BVDV), Murine encephalomyocarditis virus (EMCV), and Porcine parvovirus (PPV), were selected for this study. The mechanism of reduction for the enveloped viruses (BHV and BVDV) during fraction III fractionation was both inactivation and partitioning, however, it was partitioning in the case of the nonenveloped viruses (EMCV and PPV). The log reduction factors achieved during fraction III fractionation were ${\geqq}$6.7 for BHV, ${\geqq}4.7$ for BVDV, 4.5 for EMCV, and 4.4 for PPV. Pasteurization was found to be a robust and effective step in inactivating all the viruses tested. The log reduction factors achieved during the pasteurization process were ${\geqq}7.5$ for BHV, ${\geqq}4.8$ for BVDV, 3.0 for EMCV, and 3.3 for PPV. A low pH incubation was very effective in inactivating the enveloped viruses as well as EMCV. The log reduction factors achieved during low pH incubation were ${\geqq}7.4$ for BHV, ${\geqq}3.9$ for BVDV, 5.2 for EMCV, and 2.0 for PPV. These results indicate that the low pH treatment successfully improved the viral safety of the final products.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1729-1734
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• 2008

Chitosan, a cationic polysaccharide, has been widely used as a dietary supplement and in a variety of pharmacological and biomedical applications. The antifungal activity and mechanism of action of low molecular weight water-soluble chitosan (LMWS-chitosan) were studied in fungal cells and vesicles containing various compositions of fungal lipids. LMWS-chitosan showed strong antifungal activity against various pathogenic yeasts and hyphae-forming fungi but no hemolytic activity or cytotoxicity against mammalian cells. The degree of calcein leakage was assessed on the basis of lipid composition (PC/CH; 10:1, w/w). Our result showing that LMWS-chitosan interacts with liposomes demonstrated that chitosan induces leakage from zwitterionic lipid vesicles. Confocal microscopy revealed that LMWS-chitosan was located in the plasma membrane. Finally, scanning electron microscopy revealed that LMWS-chitosan causes significant morphological changes on fungal surfaces. Its potent antibiotic activity suggests that LMWS-chitosan is an excellent candidate as a lead compound for the development of novel anti-infective agents.

• Genomics & Informatics
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• v.18 no.1
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• pp.5.1-5.5
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• 2020

Highly pathogenic avian influenza (HPAI) viruses have caused severe respiratory disease and death in poultry and human beings. Although most of the avian influenza viruses (AIVs) are of low pathogenicity and cause mild infections in birds, some subtypes including hemagglutinin H5 and H7 subtype cause HPAI. Therefore, sensitive and accurate subtyping of AIV is important to prepare and prevent for the spread of HPAI. Next-generation sequencing (NGS) can analyze the full-length sequence information of entire AIV genome at once, so this technology is becoming a more common in detecting AIVs and predicting subtypes. However, an analysis pipeline of NGS-based AIV sequencing data, including AIV subtyping, has not yet been established. Here, in order to support the pre-processing of NGS data and its interpretation, we developed a user-friendly tool, named prediction of avian influenza virus subtype (PAIVS). PAIVS has multiple functions that support the pre-processing of NGS data, reference-guided AIV subtyping, de novo assembly, variant calling and identifying the closest full-length sequences by BLAST, and provide the graphical summary to the end users.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.210-216
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• 1995

Alternaria spp.were predominantly isolated from the abnormal leaf spot lesions of pear cultivars Niitaka and Nijiiseiki. Alternaria isolates from the cultivar Niitaka were not pathogenic to both cultivars, but the isolates from the cultivar Nijiiseiki developed typical lesions of black leaf spots and were identified as A. kikuchiana. However, no typical abnormal leaf spot lesions were produced by the Alternaria isolates. Foliar spray of twelve different agrochemicals including lime sulfur, either alone or in combinations, with 7 times applications from April to July failed to reduced the disease development. Application of 17 different pesticides including fungicides, insecticides and herbicides currently used in pear orchards did not cause leaf injury similar to the abnormal leaf spot. Simulated acid rain of as low as pH 3.0 did not incite any leaf lesions alike the abnormal spot lesions. Mineral contents in the leaves of both cultivars did not differ significantly between the healthy leaves and those with abnormal leaf spots. When cuttings of pear tree were obtained in February from newly emerged twigs of the healthy or the diseased trees of Niitaka and planted in sand in the greenhouse, only those from the diseased trees developed typical leaf lesions of the abnormal spot. These results indicate that abnormal leaf spots are caused by unknown systemic agents in pear trees, rather than by Alternaria spp., chemical injury or acid rain.

• Korean Journal of Veterinary Research
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• v.52 no.4
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• pp.253-257
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• 2012

The purpose of this study was to investigate the prevalence of Brachyspira species and antimicrobial susceptibility of Brachyspira (B.) hyodysenteriae isolates in Korea. A total of fifty-five Brachyspira species were isolated; five (1.0%) beta-hemolytic Brachyspira species and 50 (10.4%) weak hemolytic Brachyspira species from 116 different diarrheic pig samples and 367 apparently normal pig samples. In farm level, beta hemolytic and weak hemolytic Brachyspira species were detected in 7.4% (5/68) and 19.1% (13/68) of tested pig farms, respectively. By phenotypic and genotypic characterization, all beta hemolytic Brachyspira isolates was classified as group I (B. hyodysenteriae), whereas weak hemolytic Brachyspira species isolates were group III (B. innocens or B. murdochii). B. hyodysenteriae isolates showed high level of minimum inhibition concentrations to macrolide antimicrobials. This study shows that the prevalence of pathogenic B. hyodysenteriae in pigs is low but antimicrobial resistance of the pathogens is high in Korea. This is the first report of the prevalence of Brachyspira group III and antimicrobial susceptibility of B. hyodysenteriae in pigs in Korea. Our results could provide basic data for the management and treatment guidelines of Brachyspira infection.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.1
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• pp.157-163
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• 2008

Infection of pathogenic microsporidia, Nosema bombycis and Nosema mylitta (Chakrabarti and Manna, 2006) decreased egg production, fecundity, hatching % and increased sterile eggs in heavily infected mulberry silkmoth, Bombyx mori L. On an average a disease free moth laid upto 442.67 eggs with high hatching % (99.53) and less sterile eggs ($0.47{\sim}2.00%$). While an infected moth laid less number of eggs ($7.00{\sim}412.00$) with low hatching % ($32.437{\sim}98.643$) and high sterile eggs ($2.143{\sim}129.571$). Fecundity of disease free laying was highest (468.714) during season-1 then gradually decreased during season- 2 (414.000) to season- 3 (404.285). But fecundity of an infected laying was highest during season-2 and hatched eggs were lowest during season-2. Higher inoculums concentration of N. mylitta infected to 5th stage larva of mulberry silkworm drastically decreased the fecundity in season - 3 and lower inoculums concentration of N. bombycis decreased the fecundity in season-1 and 3. Season-3 was most effective season to decrease the fecundity and increase sterile eggs when both temperature and humidity were fluctuated from the optimum level.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.492-499
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• 2017

Combined treatment with gaseous and aqueous chlorine dioxide ($ClO_2$) was performed to improve the microbiological safety and quality of paprika. A single treatment of 50 ppmv $ClO_2$ gas for 30 min decreased the populations of Escherichia coli O157:H7 and Salmonella Typhimurium by 2.33 and 2.91 log CFU/g, respectively. In addition, a single treatment of aqueous $ClO_2$ (50 ppm) for 5 min decreased these populations by 1.86 and 1.37, respectively. The most dramatic effects were achieved by combined treatment of 50 ppm aqueous and gaseous $ClO_2$ for 30 min, which decreased populations of E. coli O157:H7 and S. Typhimurium by 4.11 and 3.61 log CFU/g, respectively. With regard to the qualities of paprika, no adverse effects were elicited by the combined treatment. Thus, combined treatment with aqueous and gaseous $ClO_2$ is a suitable approach that can be used to improve the microbial safety and quality of paprika.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1797-1804
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• 2007

Lycopene, an acyclic carotenoid found in tomatoes (Lycopersicon esculentum) and a number off fruits, has shown various biological properties, but its antifungal effects remain poorly understood. The current study investigated the antifungal activity of lycopene and its mode of action. Lycopene showed potent antifungal effects toward pathogenic fungi, tested in an energy-independent manner, with low hemolytic effects against human erythrocytes. To confirm the antifungal effects of lycopene, its effects on the dimorphism of Candida albicans induced by fetal bovine serum (FBS), which plays a key role in the pathogenesis of a host invasion, were investigated. The results showed that lycopene exerted potent antifungal activity on the serum-induced mycelia of C. albicans. To understand the antifungal mode of action of lycopene, the action of lycopene against fungal cell membranes was examined by FACScan analysis and glucose and trehalose-release test. The results indicated that lycopene caused significant membrane damage and inhibited the normal budding process, resulting from the destruction of membrane integrity. The present study indicates that lycopene has considerable antifungal activity, deserving further investigation for clinical applications.

• Archives of Pharmacal Research
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• v.29 no.9
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• pp.746-751
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• 2006

Amentoflavone is a plant biflavonoid that was isolated from an ethyl acetate extract of the whole plant of Selaginella tamariscina (Beauv.) spring. 1D and 2D NMR spectroscopy including DEPT, HMQC, and HMBC were used to determine its structure. Amentoflavone exhibited potent antifungal activity against several pathogenic fungal strains but had a very low hemolytic effect on human erythrocytes. In particular, amentoflavone induced the accumulation of intracellular trehalose on C. albicans as a stress response to the drug, and disrupted the dimorphic transition that forms pseudo-hyphae during pathogenesis. In conclusion, amentoflavone has great potential to be a lead compound for the development of antifungal agents.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.531-538
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• 2007

The effects of temperature, coagulants and pre-chlorination on the removal of turbidity and pathogenic protozoa by coagulation process were investigated using jar test of lab scale. In room temperature ($25^{\circ}C$), protozoa were removed over 1.0log at the proper concentration range of coagulants, and up to over 2log at the optimal concentration of coagulants. Considering the 1.5log target removal for Giardiain the processes of coagulation, sedimentation, and filtration, this results implies that the target could be satisfied. However, the removal of protozoa and turbidity was reduced, and optimal PAC concentration was narrowed in low turbidity and cold temperature ($5^{\circ}C$). These results suggest that the drop of coagulation efficiency may be occurred in winter if the conditions are not optimized. Despite the effect of water temperature, the relation of turbidity and protozoa removal appeared to be good. The various kinds of coagulants did not significantly affected for removals of turbidity and protozoa when the concentrations of $Al_2O_3$ were considered. Prechlorination did not increase or decrease the removal of turbidity and protozoa in optimum condition at room temperature, pH 7, 15mg/L of PAC concentration.