目的 揭示金黄色葡萄球菌感染对泌乳期羊的乳腺导管及腺泡的三维立体构造的影响。 方法 选取3头产后母羊并建立羊乳腺炎模型，在羊左侧乳腺注射浓度为10¹² CFU/L的金黄色葡萄球菌1 ml，右侧乳腺作为对照，注入1 ml生理盐水，羊的左侧乳腺在攻菌12 h、24 h、36 h、48 h后，观察其临床症状。使用奶牛隐性乳房炎快速诊断技术（BMT）确认乳腺炎模型构造成功，取下乳腺后运用导管铸型技术获得羊乳腺导管、腺泡的铸型标本，利用扫描电子显微镜技术，检测乳腺小导管及腺泡的微观结构。 结果 铸型标本结果显示，以输乳管为第1级，最多可达14级分支，导管分支间未见吻合现象，各级分支导管与上一级导管主轴延长线的夹角＜90°。经扫描电子显微镜观察发现，正常乳腺导管末梢小导管管壁光滑，末端多呈膨大球状，腺泡直径（79.03±14.91）μm，金黄色葡萄球菌感染的乳腺导管表面有凹陷，末端大部分腺泡萎缩，腺泡直径（42.89±17.17）μm。 结论 金黄色葡萄球菌感染能破坏乳腺腺泡的正常结构。

Objective To establish a sheep mastitis model in order to investigate the three dimensional morphological structure of the sheep mammary duct and alveolus structure. Methods Three postpartum sheep were used to establish a model of the sheep mastitis.Staphyloccus aureus (10¹² CFU/L) was inoculated into the left mammary gland and the equal amount of physiological saline was injected into the right mammary gland as the control. The milk of left and right mammary gland was detected by Beijing mastitis test (BMT) in different times (12 hours, 24 hours, 36 hours, 48 hours). The both mammary ducts and alveoli were molded by a casting mould technique and observed by scanning electron microscopy (SEM). Reselts The result showed the lactiferous duct was the first grade，including 14 branches. There was no connection between duct branches. The intersection angle between mammary duct ramification and the spindle extension was less than 90 degrees. The SEM found that the surface of right mammary ducts was smooth. There were many mammary alveoli at the terminal duct. The mean diameter of left alveolus was (79.03±14.91)μm. There were many ostioles on the surface of the left mammary ducts. The surface of the left mammary ducts was rough and most alveoli were atrophic. The mean diameter of left alveolus was (42.89±17.17)μm. Conclusion Staphyloccus aureus may destroy the construction of the mammary gland.