金黄色葡萄球菌诱发小鼠实验性乳腺炎研究

为建立小鼠乳腺炎模型,本试验选用35只泌乳期BALB/C雌鼠随机分成7组,其中6组于产后8~10 d分别用灭菌生理盐水和不同浓度的金黄色葡萄球菌悬液50μL经乳头管注入到小鼠的第4对(腹部)乳腺内,观察小鼠体温、组织病理学、间质宽度、腺泡壁厚度的变化以及乳腺组织中CFU、TNF-α和IFN-γ含量变化。结果表明:试验组小鼠体温呈现先下降后上升的趋势,以T3组明显;组织病理学显示乳腺上皮脱落,腺泡腔内大量炎性细胞浸润,以嗜中性粒细胞为主,腺泡内空泡减少,间隔增宽,炎症明显。而随着金黄色葡萄球菌用量的加大,乳腺组织的炎症程度加剧。T3组间质宽度高于其他组。与对照组相比,T3组小鼠乳腺组织中腺泡壁厚度、CFU、TNF-α及IFN-γ含量极显著升高(P<0.01)。结果表明金黄色葡萄球菌诱发小鼠试验性乳腺炎模型与炎症的免疫病理过程和炎性反应一致,可用作病理模型使用。

Study on experimental mastitis induced by Staphylococcus aureus in mice

To establish mice mastitis model,thirty-five lactating BALB/C female mice were random1y divided into seven groups.50 μL of sterile physiological saline solution(PSS) or different concentration of Staphylococcus aureus were injected into the fourth abdominal mammary gland via the teat duct at 8～10 d after parturition.The changes of temperature,histopathologic evaluations,interstitial width,alveoli cases thickness from each group and colony for units(CFU),Tumor necrosis factor-α(TNF-α)and interleukin-γ(IFN-γ) concentration in the mammary glands were examined.The results showed that the temperature of treatment groups decreased at the beginning,and then increased,particularly in T3 group.Histopathologic examination of mammary gland revealed that the number of polymorphonuclear neutrophils(PMN) and exfoliated epithelial cells were present in alveoli cases,with increased interval width,and inflammation of the mammary glands was significant.Along with the increase of dose,pathological changes of mammary glands became more serious.The interstitial width of T3 group was wider than those of other groups.In comparison with those of PSS-treated mice,alveoli cases thickness,CFU,TNF-α and IFN-γ concentration were significantly(P<0.01)higher in 50 μL1.4×104 CFU/mL Staphylococcus aureus-infused mammary glands.The results demonstrated that the mice experimental mastitis model infused with Staphylococcus aureus via teat duct was the same as immunopathology and inflammatory response,and can be used as a pathological model.