Bollgren I, Winberg J
Acta Paediatr Scand. 1976 Jan;65(1):74-80. doi: 10.1111/j.1651-2227.1976.tb04410.x.
The present study was undertaken to provide information about the presence of bacterial flora in the periurethral region of healthy children and its variation with age and sex. It was intended as a basis for subsequent studies in individuals prone to urinary tract infection. Quantitative methods were used for bacteria sampling and culture. The study included 394 girls and 305 boys from birth to 16 years. During the first few weeks of life a massive aerobic bacterial flora (E. coli, enterococci, staphylococci) was established in the periurethral region of both sexes. The colonization with E. coli and enterococci began to diminish already during the first year of life and became very scanty after the age of 5 years. In newborns E. coli colonization was dense in boys and scanty in girls. Later E. coli was the dominating gram-negative species in girls of all age groups. In boys E. coli dominated during the first half year of life, later Proteus was as common as E. coli; staphylococci did not change very much. Urine samples from healthy school-children contained very few gram-negative bacteria; even when collected without preceding cleansing. The results suggest that there might be a local defence mechanism maturing during the first year of life, eventually protecting the exposed area from colonization with gram-negatives and enterococci.
本研究旨在提供关于健康儿童尿道周围区域细菌菌群的存在情况及其随年龄和性别的变化信息。该研究旨在作为后续对易患尿路感染个体进行研究的基础。采用定量方法进行细菌采样和培养。该研究纳入了394名女孩和305名男孩，年龄从出生至16岁。在生命的最初几周，两性的尿道周围区域都建立了大量需氧细菌菌群（大肠杆菌、肠球菌、葡萄球菌）。大肠杆菌和肠球菌的定植在生命的第一年就开始减少，5岁以后变得非常稀少。在新生儿中，大肠杆菌在男孩中的定植密集，在女孩中稀少。后来，大肠杆菌是所有年龄组女孩中占主导地位的革兰氏阴性菌。在男孩中，大肠杆菌在生命的前半年占主导地位，后来变形杆菌与大肠杆菌一样常见；葡萄球菌变化不大。健康学童的尿液样本中革兰氏阴性菌很少；即使在没有事先清洁的情况下采集也是如此。结果表明，可能在生命的第一年有一种局部防御机制逐渐成熟，最终保护暴露区域免受革兰氏阴性菌和肠球菌的定植。
