• Korean Journal of Veterinary Research
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• v.31 no.1
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• pp.63-69
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• 1991

The serotypes and pathogenicity of 47 isolates of Erysipelothrix rhusiopathiae from pigs with acute septicemic swine erysipelas were investigated. The serotypes were determiend by agar gel precipitation test using autoclave extracted antigens. All of the 47 isolates(42 strains from Youngnam and fi fotrains from Kyunggi province) were serotype lao Five field isolates of Erhusiopathiae serovar la were tested for pathogenicity in mice. All of 5 selected isolates were pathogenic for mice and $LD_{50}$ was $3.7{\times}10^3$ viable cells. Mice immunized subcutaneously with live vaccine did not die after challenge with virulent isolates of E rhusiopathiae.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.413-420
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• 1990

The present study was conducted to investigate biochemical properties and antimicrobial drug susceptibilities of 47 strains of E rhusiopathiae isolated from the cases of acute septicemic swine erysipelas in Youngnam and Kyunggi provinces during the period from June 1988 to December 1989. The isolants were identified as E rhusiopathiae on the basis of cellular and colonial morphology, and characteristic reactions in some biochemical tests. All the organisms produced hydrogen sulfide in triple sugar iron agar and showed the characteristic "pipe cleaner" type of growth in gelatin stab cultures. The majority of biochemical and cultural properties of E rhusiopathiae isolated from pigs affected with acute erysipelas were identical to those of the reference strains employed. All the isolates were highly susceptible to penicillin G, ampicillin, erythromycin (MIC:0.025~0.39IU or ${\mu}g/ml$), and moderately susceptible to oleandomycin, oxytetracycline, chloramphenicol(MIC:$0.78{\sim}25{\mu}g/ml$). Kanamycin and sulfadimethoxine showed no activity against the isolates(MIC:>$400{\mu}g/ml$). The MICs of dihydrostreptomycin presented two distribution peaks; of 47 strains, 5(10.6%) were resistant to dihydrostreptomycin (MIC:$400{\mu}g/ml$), while the majority of them were susceptible to the drug.

• Korean Journal of Veterinary Service
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• v.14 no.1
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• pp.49-61
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• 1991

The present study was conducted to investigate biochemical, serologic, and pathogenic characteristic of E. rhusiopathiae isolated from the cases of acute septicemic swine erysipelas in Youngnam provinces during the period from June 1988 to September 1990. The majority of biochemical and cultural properties of E. rhusiopathiae isolated from pigs affected with acute erysipelas were identical to those of the standard strain employed. All of the 45 isolates were serotype la. All isolates were highly susceptible to penicillin G, lincomycin, cephalothin, ampicillin, erythromycin (MIC : 0.025-0.78IU or ${\mu}g$ / ml ), and moderately susceptible to oleandomycin, oxytetracycline, chloramphenicol (MIC : 0.78-25${\mu}g$ / ml ). Kanamycin and sulfadimethoxine showed no activity against the isolates(MIC : ＞400${\mu}g$ / ml ). The MICs of dihydrostreptomycin presented two distribution peaks ; of 45 strains, 5(11.1%) were resistant to dihydrostreptomycin(MIC : 400${\mu}g$ / ml ). All of 5 selected isolates were pathogenic for mite and $LD_{50}$ was $3.7{\times}10^3$viable cells. Mice immunized subcutaneously with live vaccine did not die after challenge to virulent isolates of E. rhusiopathiae.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.507-516
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• 1994

The purposes of this investigations were survey of the occurred bacterial diseases, development of new animal health drug, guidance to formers on the treatment and control methods of diseases. Some series of investigations have been carried out by microbiological, pathological and serological examinations. The results could be summarized as follows. 1. A total of 953 cases of outbreaked swine diseases have been diagnosed in Clinical pathology laboratories, Bayer Vet Res Institute during 8 years (from 1986 to 1993). The high incidence diseases were colibacillosis, pleuropneumonia, streptococcal infection and pasteurellosis in decreasing order. 2. Pleuropneumonia caused by Actinobacillus pleuropneumoniae was the most important respiratory diseases and pasteurellosis by Pasteurella multocide could be confirmed in several cases. 3. Actinobacillus pleuropneumoniae 50 strains were isolated and identified by biochemical and serological tests. In serotyping test, 22 isolated strains were serotype 5, 21 strains as serotype 2, each 2 strains as serotype 3 and 7 by the coagglutination test. 4. Colibacillosis and edema discase caused by Escherichia coli has been the most predominant outbreaked disease in this investigations. The 100 isolates of E coli strains were sensitive to amikacin, colistin, enrofloxacin, gentamycin and trimethoprim -sulfamethoxazole. 5. Swine erysipelas caused by Erysipelothrix rhusiopathiae was confirmed 25 cases as acute septicemic forms. Isolates of E rhusiopathiae were highly sensitive to ampicillin, cephalothin, enrofloxcin, penicillin and tetracycline. 6. The 49 cases of hemorrhagic and necrotic enteritis in piglets were observed and 13 strains of Clostridium perfringens could be isolated and confirmed by biological and serological test. Isolates of Clostridium perfringens type C were highly sensitive to ampicillin, cephalothin, enrofloxacin, penicillin and trimethoprim- sulfamethoxazole. 7. The 14 strains of Streptococcus suis type II could be isolated from meningitis of piplets. 8. Polyserositis caused by Haemophilus parasuis and salmonellosis were observed and confirmed. Also Corynebacterial infections and several parasitosis have been also observed in this investigations.