1至4个月龄正常婴幼儿结膜囊菌群分布特征分析

Normal conjunctival flora in healthy infants aged from 1 to 4 months

目的 探讨1至4个月龄正常婴幼儿结膜囊的菌群分布及其相关影响因素.方法 横断面研究方法.2009年1至3月天津医科大学眼科中心与天津市妇女儿童保健中心合作,采取简单随机抽样研究方法选择109例接受眼病筛查的1至4个月龄的健康小儿,进行双眼结膜囊分泌物取材并做细菌培养和鉴定.应用卡方检验、t检验和回归分析方法对数据进行统计学处理,分析结膜囊细菌种类和分布以及相关影响因素.结果 结膜囊分泌物培养阳性的小儿26例（36只眼）,占23.9%.共检出7种44株细菌,包括革兰阳性球菌25株,革兰阳性杆菌18株,革兰阴性杆菌1株.其中类白喉棒状杆菌17株（17/44,38.6%）,表皮葡萄球菌16株（16/44,36.4%）,金黄色葡萄球菌6株（6/44,13.6%）.单眼分离出2种细菌者8只眼（8/36,22.2%）,均为葡萄球菌和类白喉棒状杆菌.不同月龄、性别及喂养方式的细菌培养结果差异无统计学意义（X2=0.351,X2=0.001,X2=1.182,P值均大于0.05）.结膜囊培养阳性者26例（36只眼）,培养阴性者83例（166只眼）,两组小儿的出生体重、胎龄及受检周龄比较差异无统计学意义（t=0.078,t=0.940,t=0.686,P值均大于0.05）.本研究中性别、年龄、出生体重、胎龄及喂养方式不影响结膜囊带菌状态（Wald X2=0.001,Wald X2=0.003,Wald X2=0.117,Wald X2=1.307,Wald X2=1.490,P值均大于0.05）.结论 婴儿期结膜囊正常菌群已经建立,以表皮葡萄球菌和类白喉棒状杆菌为主要菌种.葡萄球菌与类白喉棒状杆菌有共生现象.小儿结膜囊带菌状态相关影响因素仍需进一步研究.

Objective To investigate the normal conjunetival bacterial flora isolated from healthy infants aged from 1 to 4 months and to analyze its correlated factors.Methods This was a cross-sectional study.From January to March 2009,109 cases of healthy babies aged from 1 to 4 months were selected throulgh simple random sampling when they accepted health examination provided by Tianjin Medical University Eye Center and Tianjin Women and Children＇s Health Center.Conjunctival swabs were taken from both eyes and inoculated onto blood agar plates.The isolated bacteria were classified professionally.The distribution of different bacteria was investigated as well as the possible correlated factors by using t-test,X2 test and binary logistic regression of SPSS 11.5.Results 26 cases of healthy babies（23.9%）got positive culture results which consisted 44 strains of ocular bacterial isolates.25 strains were gram-positive cocci.while 18 strains gram-positive bacilli,and 1 strain gram-negative bacillus.The first three isolated bacteria were Diphthemid bacillus（17/44,38.6%）,Staphylococcus epidermitis（16/44,36.4%）,and Staphylococcus aureus（6/44,13.6%）.The two subtypes of Staphylococci coexisted with Diphthemid bacillus in 8 eyes of 36 eyes from which bacteria were isolated.The bacterial isolation rate through every month age group had no significant difference（X2=0.351,P〉0.05）.There wag no significant difference in the group of positive isolation（26 cases,36 eyes）or negative isolation（83 cases,166 eyes）through breast,formula or mixed feeding（X2=1.182,P〉0.05）.The gender had no influence on the detection of bacteria（X2=0.001,P〉0.05）.The birth weight,gestational age or examined age between the two groups had no significant difference （t=0. 078, t=0. 940, t=0. 686,P〉0. 05）. The gender, age, birth weight,gestational age and the way of feeding had no correlation with existence of conjunctival flora in these healthy infants （ Wald X2 = 0. 001, Wald X2 = 0. 003, Wald X2 = 0. 117, Wald X2 = 1. 307, Wald X2 = 1. 490, P 〉0. 05）. Conclusions The normal conjunetival flora might establish during the initial months of little babies. Staphylococcus epidermitis and Diphthemid bacillus are the most common bacteria. Future studies should be conducted to make sure whether there would be some factors correlated with the culture results.