应用α-唾液淀粉酶结合能力鉴定血链球菌

Using the Binding Capacity of Salivary α-amylase to Identify Streptococcus Sanguis Group

目的 分析血链球菌群中的细菌与α 唾液淀粉酶结合能力 ,探讨四种细菌的结合能力 ,以及这种能力的意义。方法 取 40株血链球菌群中不同细菌的标准菌株和临床分离菌株与唾液的α 淀粉酶结合。通过淀粉水解圈大小来测定淀粉酶活性 ,从而了解它和α 唾液淀粉酶的结合能力。结果 所有高登氏链球菌和 66 7%的缓症链球菌与α 淀粉酶结合能力为阳性 ,而血链球菌与口腔链球菌与α 唾液淀粉酶结合均为阴性。结论 血链球菌、口腔链球菌不能结合α 唾液淀粉酶 ,而高登氏链球菌、缓症链球菌能结合α 唾液淀粉酶 ,利用此特性可快速且有效地鉴定不同血链球菌群中各菌株。

Objective To research the difference of the binding capacity of salivary α-amylase to four subspecies of streptococcus sanguis group (SSG) and its significance.Methods A collection of 40 SSG strains including standard and clinical-separated strains was examined for the binding capacity to salivary α-amylase. The α-amylase binding assay was based on the diameter of starch hydrolysis.Results The positive results were found in all strains of streptococcus gordonii and 66.7% of streptococcus mitis. In contrast, all strains of streptococcus sanguis and streptococcus oralis lacked α-amylase binding capacity.Conclusions A rapid and easy assay described in this paper may be an important supplementary test for identifying different subspecies of SSG.