α-溶血性链球菌在健康人群口咽部分布及 生物拮抗作用

目的通过采集健康人群口咽部分泌物,分析上呼吸道中α-溶血性链球菌的分布状况,并对革兰阳性化脓性球菌进行生物拮抗试验,为进一步研究上呼吸道益生菌提供理论基础。方法随机自愿原则,用无菌咽拭子采集沈阳市年龄在3～75岁的300名健康人群咽后壁分泌物,对α-溶血性链球菌进行鉴定和定量分析。对致病菌的生物拮抗试验采用小缸杯法。结果定量分析显示不同年龄人群咽后壁的α-溶血性链球菌检出率均较高。在咽后壁菌群中α-溶血性链球菌构成比最多的是幼儿组,达到60.3%。其中唾液链球菌群在幼儿组所占比重最大;老年组人群格氏链球菌占比较大;儿童、青年、成人以缓症链球菌和口腔链球菌为主。对革兰阳性化脓性球菌的生物拮抗试验显示,1株婴儿链球菌婴儿亚种能够拮抗8株致病菌;4株分离菌只能拮抗1株病原菌,提示不同的菌株拮抗病原菌的能力差异较大。结论α-溶血性链球菌在人群中分布广,数量多,不同年龄人群的菌群构成存在差异。并且某些菌株显示出对致病菌较强的生物拮抗作用,推测这些菌株在呼吸道黏膜保护中起到重要作用,可作为上呼吸道益生菌的备选菌株。

Distribution and bio-antagonism of Alpha-hemolytic Streptococcus in the oropharynx of healthy people

Abstract: Objective To investigate the distribution of alpha-hemolytic Streptococcus in upper respiratory tract, and explore its bio-antagonism against Gram-positive pyococci so as to provide theoretical basis for further study on upper respiratory probiotics. Methods The specimens of secretions from posterior pharyngeal wall of 300 healthy individuals aged 3 to 75 years in Shenyang were collected with sterile throat swabs to identify and quantify alpha-hemolytic streptococci. Biological antagonism experiment was performed on pathogenic bacteria by using the small cylinder cup method. Results Quantitative analysis showed that the detection rate of alpha-hemolytic Streptococci in the posterior pharyngeal wall was high in different age groups. The highest composition ratio of alpha-hemolytic streptococci was seen in infant group (60.3%), among which Streptococcus salivariis accounted for the largest proportion. Streptococcus gordonii was predominant in the elderly group; Streptococcus mitis and Streptococcus oralis were predominant in children, youths and adults. The biological antagonistic test on Gram-positive pyococci showed that one strain of Streptococcus infantis infant subspecies antagonized 8 strains of pathogenic bacteria, while 4 isolates only antagonized one strain of pathogen, suggesting that different strains had different abilities to antagonize pathogens. Most of the strains with antagonistic activity belong to the genus Streptococcus mitis. Conclusion Alpha-hemolytic Streptococcus widely distributes in populations and the number is enormous. There are differences in the composition of bacterial populations among different age groups. Some strains show strong bio-antagonism against pathogenic bacteria. It is speculated that these strains play an important role in the protection of respiratory mucosa and can be used as alternative strains of upper respiratory probiotics.