Wennerstrom D E
Infect Immun. 1979 Oct;26(1):287-93. doi: 10.1128/iai.26.1.287-293.1979.
The intranasal inoculation of adult mice with saline suspensions of virulent group B streptococci serotype Ia resulted in septicemia which was lethal. Decreasing the inoculation dose of streptotocci increased the time required for their appearance in the blood and the mean time to death of the mice. Before the appearance of septicemia, the number of organisms in the lungs decreased to about 1% of the inoculation dose, and the majority could be recovered by lavage of the lungs through the trachea. In contrast, most of the organisms remained in the lavaged lungs of bacteremic mice after intranasal or intravenous inoculation. Lung surfactant obtained from infected mice was altered by a reduction in lipid and by an increase in protein. The organisms in vitro did not attack surfactant lipid labeled with [1-14C]palmitic acid, but their pathogenesis in vivo affected the permeability of the air-blood barrier, as shown by the leakage into the air spaces of plasma albumin labeled by the intravenous injection of Evans blue dye.
用毒力B族链球菌血清型Ia的生理盐水悬液经鼻内接种成年小鼠，会导致致死性败血症。降低链球菌的接种剂量会增加其在血液中出现所需的时间以及小鼠的平均死亡时间。在败血症出现之前，肺中的细菌数量减少至接种剂量的约1%，并且大多数细菌可通过经气管冲洗肺部而回收。相比之下，经鼻内或静脉内接种后，大多数细菌仍留在菌血症小鼠的冲洗肺中。从感染小鼠获得的肺表面活性物质因脂质减少和蛋白质增加而发生改变。体外实验中，这些细菌不会攻击用[1-14C]棕榈酸标记的表面活性物质脂质，但它们在体内的致病过程会影响气血屏障的通透性，这可通过静脉注射伊文思蓝染料标记的血浆白蛋白渗漏到肺泡腔中得以证明。
