Isolation and Identification of Korean type Streptococcus mutans

한국형 Streptococcus mutans의 분리 및 동정

S. mutans known as a causative causative agent of dental caries was isolated from a carious lesion of Korean in the present study. The physiological, biochemical characteristics and polysaccharide pattern of these isolates were compated with those of four laboratory strains ; AHT(a), FA-1F(b), LM7(e), and OMZ65(g). One hundred strains of oral streptococci were isolated from dental caries sites of Korean (one male and one female). Among these, 3 strains were identified as S. mutans. These strains were able to grow on selective media MS, MST, MSP, MSP1, MSB, MSBT and were stained dark pink when sprayed with solutions of mannitol and TTC. So, these strains were called strain 108, 110, and 120, respectively. Strain 108, 110, and 120 were bacitracin resistnt. As these strains contained particularly hippurate hydrolysis enzyme, they were distinguished from laboratory strains. Apart from laboratory strains, the strain 108 was not capable of fermenting lactose, the strain 110 was not able to ferment sorbitol, inulin, melibiose, raffinose and the strain120 was incapable of fermenting inulin, raffinose. All fractions of extracellular and ecll bound polysaccharide of the strain108, 110, and 120 were consisted of more glucan than fructan. Aside from laboratory strains, the isolated strains were composed of more water-insoluble glucans related adherence on solid surface than water-soluble. According to these results, the strain108, 110, and 120 had native characteristecs of S. mutans, but they were different from laboratory strains in some characteristics. Therefore, each of them was given a name to S. mutans KHC108, KHC110, and KHC120, respcetively.

한국사람으로부터 치마우식증의 원인규능로 알려진 S. mutans를 분리, 동정하였고, 이들과 기존의 실험실균주간의 생리 및 생화학적 특성과 이들이 합성하는 다당류의 구성당을 비교하였다. 분리배지인 MS. MST와 선택배지인 MSP. MSPT. MSB 그리고 MSBT에서 모두 생장하고, mannitol dehydrogenase를 분비하는 균주 108, 110 및 120이 S. mutans로 분리, 동정되었다. 분리균주와 기존의 실험실균주간의 생리 및 생화학적 특성을 비교한 결과, 본 연구에서 분리한 3균주 모두 기존의 실험실균주와는 달리 hippuraterktnqnsgogyth를 가지고 있었다. 또한 균주 108은 lactose 발효 능력이, 균주 110은 sorbitol, lactose, inulin, melibiose, raffinose 발효능력이 , 균주 120은 inulin. raffinose 발효능력이 없는 것으로 나타나 기존의 실험 실균주와는 물론 이들 각각도 다른 생리 및 생화학적 특성을 나타내었다. 상기의 결과와 같이 분리균주 108, 110 그리고 120은 생리, 생화학적 특성 및 자당으로부터 합성되는 glucan의 양에 있어서도 기존의 실험실균주와 다르게 나타나 이들을 각각 한국형 S. mutans KHC108, KHCH10, KHC120이라 명명하였다.