Kayaoglu G, Erten H, Ørstavik D
Department of Endodontics and Conservative Treatment, Faculty of Dentistry, Gazi University, Ankara, Turkey.
Int Endod J. 2005 Jun;38(6):389-96. doi: 10.1111/j.1365-2591.2005.00957.x.
To evaluate the effect of growth at pH levels from 7.1 to 9.5 on the adherence of Enterococcus faecalis to bovine serum albumin (BSA) and collagen type I.
Enterococcus faecalis strain A197A was grown in broth of adjusted pHs varying between 7.1 and 9.5. Aliquots of bacterial suspensions were added to wells coated either with BSA or with collagen type I. Bacteria adhering to the surfaces were stained with crystal violet. Spectrophotometric measurements of the dissolved stain were used to assess the number of bacteria adhering to the surfaces. The data obtained were analysed using the Kolmogorov-Smirnov test, Levene's test and Student's t-test, with alpha = 0.05 as the level for statistical significance.
The adhesion of E. faecalis to BSA-coated surfaces decreased inversely with alkalinity of the growth medium. The pH 7.1-grown bacteria bound to BSA significantly more than the other BSA groups. On the contrary, the adhesion to collagen type I-coated surfaces of bacteria grown at pH 8.0 and 8.5 was significantly greater than for those grown at pH 7.1.
A minor increase in pH up to 8.5, which may be a consequence of insufficient treatment with alkaline medicaments such as calcium hydroxide, increases the collagen-binding ability of E. faecalis, in vitro. This can be a critical mechanism by which E. faecalis predominates in persistent endodontic infections.
评估粪肠球菌在pH值从7.1至9.5条件下生长对其黏附于牛血清白蛋白（BSA）和I型胶原的影响。
将粪肠球菌菌株A197A接种于pH值在7.1至9.5之间的肉汤培养基中。取细菌悬液等分试样加入包被有BSA或I型胶原的孔中。黏附于表面的细菌用结晶紫染色。通过分光光度法测量溶解的染料来评估黏附于表面的细菌数量。使用Kolmogorov-Smirnov检验、Levene检验和Student t检验对所得数据进行分析，以α = 0.05作为统计学显著性水平。
粪肠球菌对包被BSA表面的黏附与生长培养基的碱度呈反比。在pH 7.1条件下生长的细菌与BSA的结合显著多于其他BSA组。相反，在pH 8.0和8.5条件下生长的细菌对包被I型胶原表面的黏附显著大于在pH 7.1条件下生长的细菌。
pH值轻微升高至8.5（这可能是由于氢氧化钙等碱性药物治疗不足所致）会增加粪肠球菌在体外与胶原的结合能力。这可能是粪肠球菌在持续性牙髓感染中占优势的关键机制。
