2岁儿童口腔菌斑变形链球菌检出及其蔗糖依赖性黏附能力研究

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

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。

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.