Virulence role of group B streptococcus β-hemolysin/cytolysin in a neonatal rabbit model of early-onset pulmonary infection
Virulence role of group B streptococcus β-hemolysin/cytolysin in a neonatal rabbit model of early-onset pulmonary infection
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DOI：
10.1086/428946
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发表时间：
2005-04-15
影响因子：
6.4
通讯作者：
Heldt, GP
中科院分区：
文献类型：
--
作者：
Hensler, ME;Liu, GY;Heldt, GP
我们检测了B群链球菌(GBS) -溶血素/细胞溶血素（β h/c）在新生GBS肺感染模型中的毒力作用。经气管内感染野生型（wt） GBS的家兔发生局灶性肺炎，感染18小时后，肺组织中的细菌数量是感染δ β h/c突变体家兔的100倍。与δ β h/c突变体相比，wt - GBS攻击兔的死亡率（40%对0%）、菌血症的发生和平均细菌血细胞计数均显著高于δ β h/c突变体攻击兔。注射wt GBS后，机械通气时肺顺应性受损，但注射Delta β h/c突变菌株后，肺顺应性未受损。据我们所知，这项工作首次提供了体内证据，证明β h/c毒素在GBS新生儿肺炎中发挥了关键作用，并在肺部屏障的破坏中起到了全身感染的作用。
We examined the virulence role of group B Streptococcus (GBS) beta-hemolysin/cytolysin (beta h/c) in a neonatal-rabbit model of GBS pulmonary infection. Rabbits infected intratracheally with wild-type (wt) GBS developed focal pneumonia and, by 18 h after infection, had 100-fold more bacteria in lung tissue than did rabbits infected with a Delta beta h/c mutant. Mortality (40% vs. 0%), development of bacteremia, and mean bacterial blood counts were all significantly higher in the rabbits challenged with wt GBS than in those challenged with the Delta beta h/c mutant. Lung compliance during mechanical ventilation was impaired after injection of wt GBS but not after injection of the Delta beta h/c mutant strain. This work, to our knowledge, provides the first in vivo evidence for a critical role of the beta h/c toxin in GBS neonatal pneumonia and in the breakdown of the pulmonary barrier to systemic infection.