Biochemical properties and antimicrobial drug susceptibility of Erysipelothrix rhusiopathiae isolated from the cases of acute septicemic swine erysipelas

급성 폐혈증형 돼지단독예에서 분리한 Erysipelothrix rhusiopathiae의 생화학적 특성 및 약제감수성

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.