2���ͯ��ǻ���߱�������������������������𤸽�����о�

目的    探讨2岁儿童口腔菌斑中变形链球菌（变链菌）的检出率和蔗糖依赖性黏附能力。方法    选取广州市郊花都区2008年8—9月于入托前在妇幼保健院儿保科体检的2岁高龋（龋失补牙数≥ 5）及无龋（龋失补牙数 = 0）儿童各32名，形态学、生理生化学方法对其牙菌斑进行分离鉴定；采用分光光度比浊法，检测高龋儿童和无龋儿童变链菌临床分离株对玻壁的黏附情况。结果    64名儿童中变链菌的检出率为56.25%，高龋组儿童变链菌检出率（75.00%）显著高于无龋组儿童（37.50%），差异有统计学意义（P < 0.05）。生化鉴定获得高龋儿童75株和无龋儿童34株变链菌临床分离株。在含1%蔗糖的培养基中，高龋组变链菌分离株对玻壁的黏附比为0.58 ± 0.15，略高于无龋组0.56 ± 0.13，但两组间差异无统计学意义。结论    2岁儿童变链菌检出率与高发龋相关，而未见其蔗糖依赖性黏附力对龋病高发有影响。

Acquisition of Streptococcus mutans and cell adherence among 2-year old children with different caries experience

Objective    To explore the acquisition and the sucrose-dependent cell adhesive ability of Streptococcus mutans in dental plaque of 2-year old children. Methods    A total of 32 caries-active （dmft ≥ 5） children and 32 caries-free （dmft = 0） children were selected. Clinical isolates were identified by colony morphology and biochemical tests.  Spectroscopic turbidity method was used to analyze the sucrose-dependent cell adherence to glass wall of the sucrose-containing testing tubes. Results    Acquisition of Streptococcus mutans was 56.25% in 64 children. Acquisition in caries-active children was significantly higher than in caries-free children （75.00% v.s. 37.50%，P < 0.01）. The isolated Streptococcus mutans strains were 75 strains from caries-active group and 34 strains from caries-free group. The average adhesive ratio of the Streptococcus mutans strains isolated from caries-active group was （0.58 ± 0.15） in the 1% sucrose-containing culture medium，a little higher than from caries- free group（0.56 ± 0.13），but the difference had no statistical significance. Conclusion    The results suggest that in caries-active children of 2 years old the acquisition of Streptococcus mutans is related to high incidence of caries，but the sucrose-dependent cell adherence ability has no effect on high incidence of caries.