Abstract
Plesiomonas shigelloides distributed in the aquatic systems was isolated and identified in this study and compared with the c1inica] isolates in view of their physiological characteristics, Biochemica] charactristics of the isolates of P. shigelloides one sample taken from Gupo and two samples taken from Mu]gum, were studied. However, none was isolated in Haeundae, Dadaepo, Kangdong and Nakdong estuary. The isolated bacteria had an optimum growth condition in peptone water of $25~35^{\circ}C$, pH 7.5-8.0 and 1% NaCI concentration. The cell grew most properly on the selective enrichment media which were made from adding inositol to peptone water. DNase was s]owly produced and the results were different from those of other studies. The components of the fatty acid were 3% of 3-hydroxy]ated fatty acid containing $C_{12}~C_{18}$. 0-10% cyclopropane ($C_{17:0}$), 25~30% hexadecanoic acid ($C_{16:0}$), 32~43% hexadecenoic acid ($C_{16:1}$), 1~2% octadecanoic acid ($C_{16:0}$), and 9~14% octadecenoic acid ($C_{18:1}$). Bacterio]ogica] characteristics, susceptibility of antibiotics, and the components of fatty acid of the c1inica] isolates were similar to those of the strains isolated from the aquatic systems. The strains isolated from c1inica] sources degraded lactose more fast than those isolated from the aquatic systems. There existed resistant bacteria to chlorampenicol in the strains from patients, but there were no resistant bacteria in the strains from the aquatic systems. The components of fatty acid of the clinical isolates were 0~2% $C_{17:0 cyclo}$ and 2~3% $C_{18:0}$, but those of the strains from the aquatic systems were 2~10% and 1~2%, respectvely, which showed the quantitative difference between both components.
수계에 분포하고 있는 Plesiomonas shigelloides 균을 분리, 동정하고 임상유래균과의 세균학적 특성을 비교검토하였다. 부산근교인 구포에서 채수된 사료중 1개의 시료, 물금에서의 2개의 시료에서 P. shigelloides 가 분리, 동정되었으나 해운대, 수영, 다대포, 낙동강하구언, 강동 등에서 채수된 시료에서는 분리되지 않았다. 분리균의 최적 증식조건은 peptone water 에 $25~35^{\circ}C$ pH 7.5-8.0, NaCl 농도는 1%이하였고, 선택성 중균배지로서는 alkaline peptone water 에 insitol 을 첨가한 것이 증식이 가장 우수하였다. 생화학적 특성에 있어서는 DNase 가 다른 연구결과와는 달리 느리게 생성되었고, 지방산 조성은 $C_{12}~C_{18}$ 3-hydroxylate 지방산이 3%, cyclopropane ($C_{17:0}$ 이 0~10%, hexadecanoic acid ($C_{16:0}$) 가 25-30%, hexadecenoic acid ($C_{16:1}$) 가 32-43%, octadecanoic acid ($C_{18:0}$) 가 1-2%, octadecenoic acid( $C_{18:1}$)가 9~14% 등으로 나타났다. 임상유래균주와 수계에서 분리한 균주의 생화학적 특성 및 항생제 감수성, 지방산 조성은 비슷하였다. 환자에서 분리된 균주가 수계에서 분리한 균주보다 lactose 분해속도가 빨랐고, chloramphenicol 에 대한 내성을 나타내는 균주가 있었지만 수계에서 분리된 균주는 내성을 나타내지 않았다. 지방산 조성에서 임상유래 균주는 $C_{17:0cyclo}$ 0~2%, $C_{18:0}$ 0~2% 였으나, 수계의 균주에서는 각각 2~10%, 1-2%로 양적인 차이를 보였다.
