School of Biosciences, College of Life and Environmental Sciences, School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
Infect Immun. 2012 May;80(5):1650-61. doi: 10.1128/IAI.05443-11. Epub 2012 Feb 13.
Group B Streptococcus (GBS) is a leading cause of neonatal meningitis and septicemia. The ability of this organism to survive inside phagocytic cells is poorly understood but thought to be an important step for the establishment of disease in the host. Here, we demonstrate that GBS shows prolonged survival within J774 macrophages and that the capacity to survive is not significantly changed across a diverse range of strains representing different serotypes, multilocus sequence types (MLST), and sites of clinical isolation. Using staining for the lysosome-associated membrane protein (LAMP) and by pharmacological inhibition of phagosome acidification, we demonstrate that streptococci reside in a phagosome and that acidification of the phagosome is required for GBS to survive intracellularly. Moreover, we show that the GBS two-component system CovS/CovR, which is the major acid response regulator in this organism, is required for survival inside the phagosome.
B 群链球菌（GBS）是导致新生儿脑膜炎和败血症的主要原因。该生物体在吞噬细胞内存活的能力尚未得到充分了解，但被认为是在宿主中建立疾病的重要步骤。在这里，我们证明 GBS 在 J774 巨噬细胞内有长时间的存活能力，并且在代表不同血清型、多位点序列型（MLST）和临床分离部位的不同菌株之间，其存活能力没有明显变化。通过对溶酶体相关膜蛋白（LAMP）的染色和通过吞噬体酸化的药理学抑制，我们证明链球菌存在于吞噬体中，并且吞噬体酸化是 GBS 在细胞内存活所必需的。此外，我们还表明，GBS 的双组分系统 CovS/CovR，是该生物体中主要的酸响应调节剂，对于在吞噬体中存活是必需的。
