• Journal of fish pathology
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• v.26 no.2
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• pp.99-110
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• 2013

Hatchery-reared seeds provides a key source of animal protein for human consumption and restocking for fishery management. For stock enhancement program, we have inspected the hatchery-reared seeds of 33 species in 2009, 44 species in 2010, 43 species in 2011 and 46 species in 2012 for legally designated diseases. Results showed that abalone was the most abundant in the marine species group and then sea cucumber, olive flounder, rockfish and swimming crab were followed. Crucian carp was the most abundant and then mandarin fish, Korean bullhead, melanian snail and Chinese mitten crab were followed in the freshwater species group. The number of inspection for black sea bream, rock bream, scorpionfish, black scraper, and eel has continuously decreased for four years. The inspection for flathead mullet has been carried out only in 2009. The total number of inspection cases for eight pathogens in this study were 8,476 and disqualification cases were 56 (0.67%) by detection of aquatic animals pathogens such as koi herpesvirus, white spot syndrome virus, red sea bream iridovirus or viral haemorrhagic septicemia virus.

• Korean Journal of Microbiology
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• v.34 no.1_2
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• pp.69-73
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• 1998

We have cloned and analyzed cDNA coding for nucleocapsid protein N from infectious hematopoietic necrosis virus(IHNV), IHNV-PRT, which was isolated in Korea. The N gene had open reading frame of 1,176 bp that encoded a 391 amino acids with a molecular weight of 42.3 kDa. The deduced amino acid sequence of N protein was 75-90% identical to those of foreign isolates, IHNV, but was 43% and 38% identical to those of other species of fish rhabdovirus, hirame rhabdovirus(HRV) and viral hemorrahagic septicemia virus(VHSV), respectively. However, it revealed high levels of sequence identity between 214-265 amino acid sequences among all species of fish rhabdovirus.

• Journal of fish pathology
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• v.24 no.2
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• pp.121-129
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• 2011

Aquatic animal raised in hatcheries play an important role in supplying seedling to stock enhancement and seed quality, especially, seed health is the key factor for survival in the field after release and for stocking effectiveness. We have inspected the hatchery-reared seeds of 33 marine species and 12 freshwater species for legally designated diseases in stock enhancement program in 2010. Results showed that abalone was the most abundant as 20.0% in the marine species group and then sea cucumber (15.6%), olive flounder (8.4%), rockfish (6.7%), black sea bream (6.3%) and swimming crab (6.1%) were followed. Crucian carp was the most abundant as 19.4%, and then eel (11.8%), Korean bullhead (10.9%), mandarin fish (10.8%), melanian snail (8.4%), catfish (7.7%) were followed in the freshwater species group. The total number of inspection cases for eight pathogens in this study were 2,105 and disqualification cases were 30 by detection of aquatic animals pathogens such as koi herpesvirus (KHV), red sea bream iridovirus (RSIV), white spot syndrome virus (WSSV) or viral haemorrhagic septicemia virus (VHSV).

• The Journal of the Korean Society for Microbiology
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• v.35 no.3
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• pp.251-261
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• 2000

V. vulnificus is an estuarine bacterium which causes septicemia and shock in susceptible patients. The organism produces a hemolytic cytolysin (VvH), which has a membrane damaging effect on erythrocytes. To clarify the mechanisms by which VvH might contribute to virulence, we examined its effect on macrophages. When mouse peritoneal macrophages were harvested and co-cultured with hemolysin-positive V. vulnificus strains (100 bacteria/cell), about 60% of the macrophages were killed; macrophages were not killed when co-cultured V. vulnificus strain CVD 707, a VvH-negative deletion mutant. Exposure of macrophages to filtered culture supernatants (2.5 HU/ml) and purified VvH (3 HU/ml) resulted in an increase in dead cells (80 and 90%, respectively), as determined by the trypan blue dye exclusion method and LDH release from macrophages was also increased (70 and 65.5%, respectively). The cytotoxic effect of VvH on macrophages was both the dose- and time-dependent. The VvH caused damage to the macrophage membrane and was blocked significantly by preincubation with cholesterol (p<0.01). Fetal bovine serum showed remarkable inhibition of VvH synthesis by V. vulnificus and inhibited VvH activity in culture supernatant. Cell viability was increased by 35% (p<0.01) and LDH release decreased by 28% (p<0.01) when macrophages were incubated with V. vulnificus (100 bacterial cell) in DMEM-10% FBS for 2 hr. Bacterial clearance activity of mice against V. vulnificus CVD 707 was decreased by pretreatment with 10 HU of VvH. This result suggests that the VvH can impair the membrane of macrophages and may playa role in the pathogenesis of V. vulnificus septicemia.

• Korean Journal of Microbiology
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• v.30 no.1
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• pp.15-29
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• 1992

Vibrio vuln$cus has been recognized as a pathogen of septicemia and wound infection, when the organism attacks high-risk persons with a history of hepatic disease. alcohol abuse. diabetes or any debilitative disease. Forty six strains of K vulnzjicus. isolated from 1025 marine specimens from May to Novemver for three years. from 1985 to 1987. were studied for their biochemical properties. growth requirements, serotype and drug susceptibilities. The isolates were different in their various biochemical reactions. Ninety-five percent of isolated strains were able to ferment lactose, while most strains didn't utilize sucrose in their biochemical test, for example ornithine, gelatin and mannitol were quite dit'ferent composition than those described in other reports. It was found that the biochemical test wasn't useful for identifying strain. The type of somatic 0 antiserum was determined in isolates from marine sources and in patients with Vibrio septicemia. In patient isolates. 1-2 group were 24% and 1-4 group were 42%. However. 02 group(33%) were more abundant in isolates from marine sources. Minimal inhibitory concentrations(M1Cs) of chloramphenicol, tetracycline. erythromycin and ampicillin were determinef for V vuln~ficus by broth dilution method. MIC90 was I , 0.25, :! and 4,ug/ml in patient isolates. 1, 0.25, 2 and 2 ,ug/ml in marine isolates. The divalent chelating agent, IDTA. inhibited the growth of V. vuln!'ficus at 6.25 mMlml of MIC90.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.180-185
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• 2006

Invasive Pseudomonas infections most often occur in the immunocompromised patients and are associated with high mortality rate. Rarely this disease may develop in healthy infants and children. We report two cases of invasive Pseudomonas aeruginosa infections that were diagnosed in otherwise healthy infants. The first case was a previously healthy 5-month-old infant with ecthyma gangrenosum and septicemia. She presented with fever, swelling of left periorbital area and multiple erythronodular skin lesions. Each skin lesion formed a black eschar surrounded by an erythematous areola over time. Cultures of blood, urine and discharge from skin lesions grew P. aeruginosa. On the day of visit, she showed pancytopenia which was normalized after 10 days. The patient responded well to the management with ceftazidime and tobramycin. The other case was a previously healthy 9-month-old infant with community-acquired pneumonia. He was referred from an outside hospital with fever and cough. Chest x-ray revealed pneumonic infiltrations on both lower lungs with pleural effusion on the right side. Cultures of blood and pleural fluid grew P. aeruginosa. Chest CT performed on the ninth day demonstrated pneumatoceles, lung abscess and necrosis of lung parenchyma. He was managed with ceftazidime and amikacin for 50 days. No residual pulmonary complications were noted during the three month follow-up. Laboratory results to evaluate immunologic defects of phagocytic cells, complement components and T- and B-lymphocytes were all within normal range in both patients. It should be kept in mind that Pseudomonas can be, though uncommon, a cause of community-acquired invasive infections in the previously healthy infants.

• Journal of Life Science
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• v.25 no.2
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• pp.214-222
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• 2015

Aeromonas hydrophila is the most common water fish pathogen and cause diseases such as hemorrhagic septicemia, dropsy, ulceration and asymptomatic septicemia. A. hydrophila secretes many extracellular products (ECPs) which contribute to effective infection, wide distribution and great adaptability to environmental changes. Crude ECPs of A. hydrophila CK257, a strain used in this study, exhibits a toxic activity to the animals including mouse, rabbit and fish. Toxic symptoms were indicated by tissue damage and skin injuries in animal. When ECPs were subcutaneously injected to animals, skin damages were observed, appearing like necrosis. Preliminary research demonstrated that the active factors are protein component. The crude ECPs were collected after ammonium sulfate precipitation of cell-free culture supernatant. ECPs were fractionated with the use gel filtration chromatography. Five ECP fractions were obtained, of which one fraction was found to be toxic to goldfish. MALDI-TOF analyses provided two interesting proteases called M35 and M28. Both M35 and M28 are known as metalloprotease. Accordingly, proteins in an active fraction exhibited caseinolytic activity. These proteins were difference of caseinolytic activity under different metallic ions. Also active fraction has elastolytic activity. These results suggested that peptidase M28 and M35 may be a candidate factor for tissue necrosis activity about infection with A. hydrophila.

• Journal of fish pathology
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• v.26 no.3
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• pp.283-287
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• 2013

The susceptibility of marine medaka, Oryzias dancena to fish pathogenic viruses (infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), hirame rhabdovirus (HIRRV), infectious hematopoietic necrosis virus (IHNV), and lymphocystis disease virus (LCDV)) was investigated. The cumulative mortalities of fish immersed with IPNV (experimental condition: $15^{\circ}C$ sea water (SW)), VHSV ($15^{\circ}C$ SW), HIRRV ($15^{\circ}C$ fresh water (FW)) were 30%, 40% and 60%, respectively. In the fish immersed with IPNV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), VHSV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), HIRRV ($15^{\circ}C$ SW), IHNV ($15^{\circ}C$ FW and SW), LCDV ($15^{\circ}C$ FW and SW, $18^{\circ}C$ FW and SW), and mock-challenged group, mortality rate was less than 10%. IPNV, VHSV and HIRRV were re-isolated from the dead fish. These results suggest that marine medaka is susceptible to IPNV, VHSV and HIRRV, although their susceptibility depends on the environmental conditions.

• Korean Journal of Veterinary Research
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• v.29 no.2
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• pp.91-98
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• 1989

The effects of the serum total protein and immunoglobulin levels of the colostrumconferred Korean native calves at 2 days of age on the disease incidence during the suckling period were studied. The results obtained were summerized as follows: 1. Serum total protein, total immunoglobulin, IgG, and IgM levels of 6 Korean native claves died from septicemia were lower than those of calves survived (p<0.05). 2. Korean native calves having low serum total protein and immunoglobulins were affected with diarrhea earlier in life, when compared with calves having high serum levels (p<0.05). 3. Korea native calves having low serum total protein were affected with bronchopneumonia earlier in life, when compared with calves having high serum levels (p<0.05). 4. Korean native calves having low serum neutralizing antibody titers to bovine viral diarrhea virus had high incidence rate of BVD, when compared with calves having high serum neutralizing antibody titers (p<0.05).

• Korean Journal of Veterinary Research
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• v.31 no.2
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• pp.201-208
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• 1991

In studies on Erysipelothrix rhusiopathiae infection of pigs, a series of investigations were conducted for isolation, biochemical properties, pathogenicity, serotyping and susceptibility to antimicrobial agents. The results could be summarized as follows: 1. A total of 14 isolates of E rhusiopathiae were made from an acute form of swine erysipelas and the incidence was high during the hot summer season. 2. The biochemical properties of the 14 isolates were identical to the reference strain of E rhusiopathiae. 3. Pathogenicity of the isolated strain(89368) were ascertained that $LD_{50}$ for mice was $1.8{\times}10 $ cfu and also typical urticarious lesions and acute septicemia for pigs were induced by intradermal and intravenous inoculation with isolates, respectively. 4. All isolates were serotyped by the agarose gel slide double-diffusion system and proved to be serotype 1. 5. In susceptibility test to antimicrobial agents, 14 isolates of E rhusiopathiae were highly sensitive to ampicillin, baytril, cephalothin, chloramphenicol, penicillin and tetracycline.