• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1443-1457
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• 2020

The emergence and spread of antimicrobial resistance in pathogenic bacteria of fish and shellfish have caused serious concerns in the aquaculture industry, owing to the potential health risks to humans and animals. Among these bacteria, Aeromonas salmonicida, which is one of the most important primary pathogens in salmonids, is responsible for significant economic losses in the global aquaculture industry, especially in salmonid farming because of its severe infectivity and acquisition of antimicrobial resistance. Therefore, interest in the use of alternative approaches to prevent and control A. salmonicida infections has increased in recent years, and several applications of bacteriophages (phages) have provided promising results. For several decades, A. salmonicida and phages infecting this fish pathogen have been thoroughly investigated in various research areas including aquaculture. The general overview of phage usage to control bacterial diseases in aquaculture, including the general advantages of this strategy, has been clearly described in previous reviews. Therefore, this review specifically focuses on providing insights into the phages infecting A. salmonicida, from basic research to biotechnological application in aquaculture, as well as recent advances in the study of A. salmonicida.

• 한국어병학회지
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• 제24권2호
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• pp.47-51
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• 2011

The present study demonstrated lymphocystis disease virus (LCDV) propagation through cytopathic effects (CPE) formation and LCDV detection in olive flounder fin (FFN) cells by polymerase chain reaction (PCR) and fluorescent antibody technique (FAT) methods. Tissue filtrates from the cluster cells produced CPE in FFN cells, which initially cells became enlarged and gradually underwent fusion en masse. Infectivity of culture grown LCDV using the FFN cells reached $10^{2.3}$ $TCID_{50}$/ml at 4 days post infection and the highest titer was measured $10^{6.5}$ $TCID_{50}$/ml at 12 days. The viral DNA was detected in the cell culture supernatants showing CPE and the CPE cells by PCR. Antigen specific strong fluorescence reacting with monoclonal antibody against the virus revealed the presence of viral antigen in the cytoplasm of infected FFN cells. These results suggest that the FFN cell line originated from the olive flounder has a susceptibility of the LCDV.

• 한국응용곤충학회지
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• 제28권1호
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• pp.10-15
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• 1989

밤나방류에 대한 천적미생물을 중심으로 하는 신방제법의 개발을 목적으로 멸강나방에 강한 병원성을 갖는 바이러스의 선별시험을 실시하여 다음과 같은 결과를 얻었다. 멸강나방(Pseudaletia(=Leucania) separata, Walker)유충에 강한 병원성을 가진 핵다각체바이러스를 선별코자 21종(개통)의 NPV를 orchard grass의 양면에 발라서 멸강나방 2령 유충에 첨식한 결과 멸강나방 핵다각체병바이러스 4계통과 벼밤나방 핵다각체병바이러스가 병원성이 높았다. 멸강나방 핵다각체병바이러스 3계통(LsNPV-F, LsNPV-G 및 LsNPV-Y)를 공시해서, 다각체를 인공사료에 혼합하여 해서 멸강나방 1~6령의 유충에 대한 병원성 시험을 행한 결과 1~2령 유충에 대한 병원성이 높고, 4령 이후에는 낮아 약령기방제의 중요성을 시사했다.

• 대한바이러스학회지
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• 제28권1호
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• pp.11-20
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• 1998

Twenty isolates of Hantavirus were isolated from patients and reserovirs from 1988 to 1994 in Korea. Isolation rate was 1.9% (10/538) in patients, 6.2% (5/81) in Apodemus sp., 2.6% (1/38) in Rattus sp. and 0.6% (4/677) in bats. Reciprocal mean IFA titers ranged from 27.5 to 1,024 at the specimen collection. According to the growth rate and reaching peak titier of infectivity, the isolates were grouped as rapid, intermediate, and slow growing groups. All isolates were confirmed as Hantaan type by the nested RT-PCR on the G1 region of the M segment. Comparison of nucleotide sequence (Nt: 2101 - Nt: 2280) of the G2 region revealed that the sequence homology bewteen Hantaan 76/118 virus and the isolates was more than 90%. Several nucleotide positions of the isolates showed high variation. The variation rate of patientisolates was about one-half when compared with that of rodentisolates. On the basis of phylogenetic analysis Hantaan viruses isolated were divided into two genogroups. These results indicate that Hantaan virus is highly dominant serotype in Korea and the virologic property and genogroup are not correlated.

• Parasites, Hosts and Diseases
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• 제49권4호
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• pp.423-426
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• 2011

In the genus Cryptosporidium, there are more than 14 species with different sizes and habitats, as well as different hosts. Among these, C. parvum and C. hominis are known to be human pathogens. As C. parvum can survive exposure to harsh environmental conditions, including various disinfectants or high doses of radiation, it is considered to be an important environmental pathogen that may be a threat to human health. However, the resistance of other Cryptosporidium species to various environmental conditions is unknown. In this study, resistance against ${\gamma}$-irradiation was compared between C. parvum and C. muris using in vivo infection in mice. The capability of C. muris to infect mice could be eliminated with 1,000 Gy of ${\gamma}$-irradiation, while C. parvum remained infective in mice after up to 1,000 Gy of ${\gamma}$-irradiation, although the peak number of oocysts per gram of feces decreased to 16% that of non-irradiated oocysts. The difference in radioresistance between these 2 Cryptosporidium species should be investigated by further studies.

• 식물병연구
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• 제10권2호
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• pp.130-134
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• 2004

다른 기주에 발생하는 탄저병(C. gloeosporioides)이 딸기에 전염되는지를 알아보기 위해 사과, 고추, 대추, 감의 이병된 과실에서 탄저병균을 분리동정하고 딸기에서의 병원성을 비교하였다. 각 기주별로 분리된 C. gloeosporioides의 배양적 특성과 포자의 크기는 서로 유사하였으나 말기에 접종을 하였을 경우에는 감에서 분리된 균주가 병원성이 가장 강하였고, 대추에서 분리된 균주는 약한 병원성을 보였다. 각 기주별로 병원성을 나타내는 균주를 선발하여 포장에서 병원성을 검정하였을 때 모두 탄저병이 발병되었으므로 다른 기주에서 발생한 탄저병도 자연상태에서 딸기로 전염이 가능한 것을 확인할 수 있었다.

• The Plant Pathology Journal
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• 제22권2호
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• pp.131-138
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• 2006

Two strains of Cucumber mosaic virus (CMV) isolated in Kuwait were confirmed their infectivity based on symptomatology and host range on different cultivars of tomato (Lycopersicon esculentum), tobacco(Nicotiana tabacum L.) and squash (Cucurbita pepo). The pattern of symptoms differed for the two CMV strains in tomato and tobacco, showing severe stunting and mosaic symptoms with one strain designated KU2, and almost symptomless with the other strain designated KU1. A satellite RNA 5 (sat-RNA) was found to be associated with the KU1 strain and was characterized as a benign viral satellite RNA. Using reverse transcription and polymerase chain reaction (RT-PCR) with sat-RNA specific primers, an amplified PCR product of about 160bp was determined and analyzed by gel electrophoresis. This naturally occurring benign viral satellite RNA was successfully used as a biological control agent to protect tomato plants against the severe KU2 strain. Tomato plants grown in plant-growth chambers, were preinoculated with KU1 containing the benign viral satellite and then challenge inoculated with the severe KU2 strain at different time intervals. All plants challenged three weeks after preinoculation showed nearly complete protection from subsequent infection by the severe strain. This biological control technology using plant viruses was found protective and could be successfully established sooner after the preinoculation.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 제2회 추계심포지움
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• pp.143-145
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• 1994

Chimeric fusion proteins involving IgG have proven valuable in studying protein-protein interactions and may possess therapeutic applications as well. For example, three receptor subtypes for the natriuretic peptides, when fused to the Fc portion of human IgG ${\gamma}$ chain, were quantitatively and qualitatively indistinguishable from the native receptor, thus allowing detailed structure-function studies of the receptor. In an attempt to block human immunodeficiency virus infectivity with soluble derivatives of CD4, a CD4/IgG Fc chimeric molecule was shown to increase the plasma half life of soluble CD4 and possessed the added advantage of IgG Fc-mediated placental transfer. In the case of the KGFR, this approach provided a framework for dissection of its ligand binding domains and made it possible to demonstrate that high affinity binding sites for two ligands, aFGF and KGF, reside within different receptor Ig-like domains. Chimeric molecules fused to immunoglobulins would have the advantages of secretion from transfected cells as well as detection and purification from medium utilizing Staphylococcus aureus Protein A. In addition, where highly related receptors make their discrimination very hard due to the difficulties in generating specific immunochemical probes, IgG fusion protein with tailor-made specificities confers particular advantages to elucidate patterns of receptor distribution and expression. The approach described here may have general applications in defining ligand-receptor interactions as well as searching for specific agonists and antagonists of receptor function.

• 대한수의학회지
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• 제31권4호
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• pp.471-477
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• 1991

Attempts to isolate chicken anemia agent (CAA) were made by inoculating tissue homogenates into MDCC-MSBl or LSCC-1104B1 cell lines and passaging the cells serially. CAA was isolated from the liver and thymus of 11 weeks old layer chickens and from the liver of 10 weeks old broiler breeder chickens. The layer flock experienced approximately 45% mortality during 9 to 14 week of age from gangrenous dermatitis and lymphoid organs of affected chickens were severely atrophied. The broiler breeder flock experienced approximately 7% mortality during 7 to 9 weeks of age and affected birds showed lesions of colibacillosis, staphylococcal arthritis, and coccidiosis together with atrophied lymphoid organs. The isolated viruses were identified as CAA by the indirect fluorescent antibody test and virus neutralization test using CAA immune sera including one to Gifu-1 strain of CAA. The CAA isolate 89-69, when inoculated into susceptible 1 day old SPF chicks, induced anemia 14 to 16 days after inoculation. It did not induce any cytopathic effects in chicken embryo liver and chicken embryo fibroblast cell cultures. Infectivity of the isolate was not affected by the treatment of chloroform or heat ($70^{\circ}C$ for 15 minutes).

• Journal of Microbiology
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• 제34권3호
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• pp.253-269
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• 1996

Infection of fish cells with IHNV resulted in gradual increase in cytosolic free Ca$\^$2+/ concentration ([Ca$\^$2+/)] in CHSE, gradual decrease in [Ca$\^$2+/] in FHM, and no significant change in RTG cells. The degree of [Ca$\^$2+/] increase or decrease was dependent on the amount of infectious virus, and these [Ca$\^$2+/] variations were maximal at 16 hours after virus infection (p. i.) in both cell lines. When the fish cells were infected with inactivated IHNV, evident variation in [Ca$\^$2+/] was not observed. Thus, infectivity of IHNV appears to correlate with changes in [Ca$\^$2+/] in virus-infected cells. These IHNV-induced [Ca$\^$2+/] changes were partially blocked by cycloheximide, but not affected by cordycepin. It seems to be that virus-induced Ca$\^$2+/ variations were more related with protein synthesis than RNA synthesis. Various Ca$\^$2+/ related drugs were used in search for the mechanisms of the [Ca$\^$2+/], changes following IHNV infection of CHSE cells. Decreasing extracellular Ca$\^$2+/ concentration or blocking Ca$\^$2+/ influx from extracellular media inhibited the IHNV-induced increase in [Ca$\^$2+/], in CHSE cells. Similar results were obtained with intracellular Ca$\^$2+/ sources are important in IHNV-induced [Ca$\^$2+/] increase in CHSE cells.