ISOLATION AND IDENTIFICATION OF LACTOBACILLUS SALIVARIUS INHIBITING THE FORMATION OF ARTIFICIAL PLAQUE AND THE PRODUCTION OF VOLATILE SULFUR COMPOUNDS |
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치태 형성과 휘발성 유황화합물 생성을 억제하는 Lactobacillus salivarius의 분리 및 동정 |
김미형1, 최남기1, 김선미1, 오종석2, 양규호1 |
1전남대학교 치과대학 소아치과학교실 및 치의학 연구소 2전남대학교 의과대학 미생물학교실 |
Correspondence:
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Abstract |
There are normal inhabitants doing medically useful functions in the body. There are many kinds of bacteria performing specific functions in the oral cavity. Two strains of lactic acid bacteria were isolated from inhabitants of caries-free children's oral cavity, which inhibited the formation of artificial plaque by Streptococcus mutans and the production of volatile sulfur compounds by anaerobic bacteria. The isolates were identified by the test using API 50 CHL medium kit and 16S rDNA partial sequencing. 1. Two isolates were Gram-positive bacilli and produced hydrogen peroxide. 2. When Streptococcus mutans was cultured in the media, the mean weight of formed artificial plaque on the orthodontic wires was 124.4±30.4mg, whereas being reduced to 5.2±2.0mg and 10.6±6.6mg in the media cultured with Streptococcus mutans and each isolate, respectively (p<0.05) 3. The number of viable cells of Streptococcus mutans was 3.4×109 per ml in the cultured solution, whereas those of Streptococcus mutans in the combined culture with each of isolates were 4.6×108 and 2.4×108 per ml. 4. The optical density was 1.286 in the supernatant of Fusobacterium nucleatum after vortexing for 30minutes, whereas in the supernatant of combined Fusobacterium nucleatum and each isolate, they were reduced to 0.628 and 0.497, which the percentages of coaggregation between them were 29.4% and 57.8%, respectively 5. The optical density of Fusobacterium nucleatum precipitate was 1.794 in the culture media containing cysteine and FeSO4, being reduced to 1.144 and 0.915 in the coaggregated precipitates of Fusobacterium nucleatum and each isolate. The optical density of Porphyromonas gingivalis precipitate was 1.932 in the culture media, being reduced to 1.170 and 1.266 in the coaggregated precipitates of Porphyromonas gingivalis and each isolate. 6. When two isolates were tested with API 50 CHL medium kit, those were identified Lactobaciallius salivarius and Lactobaciallius delbrueckii subsp. lactis. 7. The similarity values of 16S rDNA sequence between each of isolates and Lactobaciallius salivarius subsp. salicinius were 99.60% and 99.73%, respectively, meaning that isolates were Lactobaciallius salivarius subsp. salicinius. These results indicated that two strains isolated from caries-free children's saliva, which inhibited the formation of artificial plaque and the production of volatile sulfur compounds, were identified as Lactobaciallius salivarius subsp. salicinius. |
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