Sissons C H, Hancock E M, Cutress T W
Dental Research Unit, Medical Research Council of New Zealand, Wellington.
Arch Oral Biol. 1988;33(10):721-6. doi: 10.1016/0003-9969(88)90005-2.
Artificial-mouth plaques were cultured for 7 days from the saliva of two individuals, one with high and one with low salivary ureolytic activity. There was a 7.5-fold range in the resulting plaque ureolysis rates (per mg of protein), and the composition of the flora varied widely. The average rate of ureolysis of artificial plaque was similar to that in natural plaques but higher than in salivary sediment (after correction of sediment rates for the presence of 50 per cent non-bacterial protein). The average rate of ureolysis per ureolytic bacterium was 2.5 times higher in the artificial plaques than in saliva. Although the saliva inocula were from subjects with a 3-fold difference in salivary ureolysis rate, this difference was not reflected in the ureolytic activity of the artificial plaques. Neither was this difference evident in the ureolytic activity of the corresponding natural plaques. The established hypothesis that plaque ureolysis is derived mainly from an unidentified active segment of the total ureolytic flora was tested in the artificial plaques by analysis of variance to determine the contribution of the known ureolytic bacteria. Plaque ureolysis rates were almost entirely explained (r2 = 86 per cent) by the percentage of total detectable ureolytic bacteria in the plaque flora. The plaque bacteria giving strong ureolytic reactions on agar plates were all Gram-positive cocci and in 6 of the 9 plaques were streptococci only. Therefore, in artificial plaques the physiologically significant bacteria comprise a high proportion of the total ureolytic flora and are Gram-positive cocci, mainly streptococci.
从两名个体的唾液中培养人工口腔菌斑7天，其中一人唾液尿素分解活性高，另一人唾液尿素分解活性低。所得菌斑尿素分解率（每毫克蛋白质）有7.5倍的差异范围，并且菌群组成差异很大。人工菌斑的平均尿素分解率与天然菌斑相似，但高于唾液沉淀物（在将沉淀物率校正为存在50%的非细菌蛋白质后）。每尿素分解细菌的平均尿素分解率在人工菌斑中比在唾液中高2.5倍。尽管唾液接种物来自唾液尿素分解率相差3倍的受试者，但这种差异并未反映在人工菌斑的尿素分解活性中。相应天然菌斑的尿素分解活性中也没有明显体现出这种差异。通过方差分析来确定已知尿素分解细菌的贡献，从而在人工菌斑中检验了既定的假说，即菌斑尿素分解主要源自总尿素分解菌群中一个未鉴定的活性部分。菌斑尿素分解率几乎完全由菌斑菌群中可检测到的总尿素分解细菌的百分比来解释（r2 = 86%）。在琼脂平板上产生强烈尿素分解反应的菌斑细菌均为革兰氏阳性球菌，在9个菌斑中的6个中仅为链球菌。因此，在人工菌斑中，具有生理意义的细菌在总尿素分解菌群中占很大比例，并且是革兰氏阳性球菌，主要是链球菌。
