哮喘患儿口咽部菌群分析及3株优势菌的拮抗作用

Respiratory tract flora in asthmatic children and evaluation of antagonistic effect of three dominant bacteria

目的了解哮喘患儿呼吸道菌群多样性及其组成特征,同时研究所分离的3株优势菌对流感嗜血杆菌的抑制作用,探究哮喘与呼吸道菌群之间的关系。方法采集沈阳市儿童医院呼吸内科2019年3月至2019年12月收治的21例4~12岁急性发作期哮喘患儿咽拭标本,并同时采集23例同龄健康儿童的咽拭标本作为对照,对呼吸道菌群进行分离培养、纯化和16SrRNA鉴定。采用牛津杯法检测健康儿童口咽部分离的3株优势菌对流感嗜血杆菌的拮抗作用。结果哮喘和健康儿童呼吸道培养出的需氧菌(t=2.143,P=0.038)和厌氧菌(t=3.270,P=0.002)的密度差异有统计学意义。哮喘患儿咽部需氧菌以肺炎链球菌和流感嗜血杆菌为主,厌氧菌以韦荣球菌为主。健康儿童咽部需氧菌以缓症链球菌和口腔链球菌为主,厌氧菌以干酪乳杆菌为主。健康儿童口咽部的3株优势菌对哮喘儿童口咽部流感嗜血杆菌的生长具有显著抑制作用。结论与健康儿童相比,哮喘患儿口咽部菌群发生紊乱,且哮喘患儿口咽部需氧菌、厌氧菌密度显著增加。健康儿童口咽部的某些优势菌可能对哮喘致病菌的定植有一定的拮抗作用。

Objective To explore the diversity of respiratory tract flora in children with asthma and its structural composition,as well as the inhibitory effect of three dominant strains on Haemophilus influenzae,and analyze the relationship between asthma and respiratory tract flora.Methods Pharyngeal swabs were collected from 21children aged 4-12years with acute asthma in the respiratory department of Shenyang Children′s Hospital from Mar 2019to Dec 2019;at the same time,throat swab samples of 23healthy children of the same age were collected as the controls.The flora were isolated,cultured,purified and identified with 16SrRNA method.Oxford cup method was used to detect the antagonistic effect of three dominant bacteria isolated from oropharynx of healthy children against Haemophilus influenzae.Results There were significant differences in the densities of aerobic bacteria(t=2.143,P=0.038)and anaerobic bacteria(t=3.270,P=0.002)between asthma children and healthy ones.In the culturable pharyngeal flora of asthmatic children,Streptococcus pneumoniae and Haemophilus influenzae were the main aerobic bacteria,while Veillonella was the main anaerobe.In the pharyngeal flora of healthy children,Streptococcus mitis and Streptococcus neonatorum were the main aerobic bacteria,and Lactobacillus casei was the main anaerobic bacteria.Conclusion Compared with the healthy control group,there exists floral disorder in the oral and pharyngeal flora of asthmatic children,and the density of aerobic bacteria and anaerobic bacteria in asthmatic children significantly increase.Some dominant bacteria in healthy children may have antagonistic effect on the coloni-zation of pathogenic bacteria of asthma.