金黄色葡萄球菌诱导大鼠乳腺炎模型的建立

Establishment of rat mastitis model induced by Staphylococcus aureus

妊娠Wistar大鼠84只,随机分为试验组和对照组(n=42)。产后第4天,试验组经第4对乳腺的乳导管灌注金黄色葡萄球菌0.1 m L(2×107CFU/m L),对照组注射同量的生理盐水。动态观察和记录大鼠的临床症状、病理组织学变化、胸腺和脾脏指数、乳腺组织内细菌数和血液学变化。结果显示,注菌后,试验组胸腺和脾脏指数显著或极显著升高(P<0.05或P<0.01);乳腺组织内细菌量在接种后6 h迅速升高,之后开始下降,直至96 h,乳腺组织仍可以检测到金黄色葡萄球菌,高于300 CFU/mg乳腺组织;外周血中的嗜中性粒细胞在接种后6 h,12 h,极显著升高(P<0.01),之后差异不显著;病理组织学检查显示,接种细菌后可导致明显的炎症反应。表明本研究建立了经乳腺导管灌注金黄色葡萄球菌诱发大鼠乳腺炎的动物模型。

84 pregnant Wistar rats were randomly divided into experiment group and control group （ n=42）. On 4th day after parturition, the 4th pair of mammary ducts in experiment group were inoculated with 0.1 mL Staphylococcus aureus （2×10^7 CFU/ mL ） and control group with equal physiological saline. Clinical sign, pathological change, thymus gland and spleen index, bacteria number recovered from mammary glands and hematology change were observed. Results ： Thymus gland and spleen index increased significantly in experiment group （ P〈0,05 or P〈0.01 ）. Bacterial burden jumped at 6 h, and then decreased. Until 96 h, over 300 CFU/mg could be recovered from mammary glands. Neutrophilic granulocyte increased significantly at 6 h, 12 h post inoculation （P〈0.01） , and then decreased. Histopathologic examination revealed that obvious inflammatory reaction in mammary glands was induced by S.aureus inoculation. So, rat mastiffs model induced by S.aureus was established successfully via mammary duct.