School of Pathology and Laboratory Medicine, The University of Western Australia, Perth, Western Australia, Australia.
PLoS One. 2013;8(2):e55798. doi: 10.1371/journal.pone.0055798. Epub 2013 Feb 6.
We compared exemplar strains from two hypervirulent clonal complexes, strain NMB-CDC from ST-8/11 cc and strain MC58 from ST-32/269 cc, in host cell attachment and invasion. Strain NMB-CDC attached to and invaded host cells at a significantly greater frequency than strain MC58. Type IV pili retained the primary role for initial attachment to host cells for both isolates regardless of pilin class and glycosylation pattern. In strain MC58, the serogroup B capsule was the major inhibitory determinant affecting both bacterial attachment to and invasion of host cells. Removal of terminal sialylation of lipooligosaccharide (LOS) in the presence of capsule did not influence rates of attachment or invasion for strain MC58. However, removal of either serogroup B capsule or LOS sialylation in strain NMB-CDC increased bacterial attachment to host cells to the same extent. Although the level of inhibition of attachment by capsule was different between these strains, the regulation of the capsule synthesis locus by the two-component response regulator MisR, and the level of surface capsule determined by flow cytometry were not significantly different. However, the diplococci of strain NMB-CDC were shown to have a 1.89-fold greater surface area than strain MC58 by flow cytometry. It was proposed that the increase in surface area without changing the amount of anchored glycolipid capsule in the outer membrane would result in a sparser capsule and increase surface hydrophobicity. Strain NMB-CDC was shown to be more hydrophobic than strain MC58 using hydrophobicity interaction chromatography and microbial adhesion-to-solvents assays. In conclusion, improved levels of adherence of strain NMB-CDC to cell lines was associated with increased bacterial cell surface and surface hydrophobicity. This study shows that there is diversity in bacterial cell surface area and surface hydrophobicity within N. meningitidis which influence steps in meningococcal pathogenesis.
我们比较了来自两个高毒力克隆复合体的模式株，ST-8/11 克隆复合体的 NMB-CDC 株和 ST-32/269 克隆复合体的 MC58 株，在宿主细胞附着和入侵方面的情况。NMB-CDC 株附着和入侵宿主细胞的频率明显高于 MC58 株。无论菌毛类和糖基化模式如何，IV 型菌毛都保留了最初与宿主细胞附着的主要作用。在 MC58 株中，B 群荚膜是影响细菌附着和入侵宿主细胞的主要抑制决定因素。在存在荚膜的情况下，去除脂寡糖（LOS）末端唾液酸化并不影响 MC58 株的附着或入侵率。然而，在 NMB-CDC 株中去除 B 群荚膜或 LOS 唾液酸化都使细菌附着到宿主细胞的程度增加。尽管这两种菌株的荚膜对附着的抑制程度不同，但两组分反应调节因子 MisR 对荚膜合成基因座的调节以及流式细胞术测定的表面荚膜水平并无显著差异。然而，通过流式细胞术显示 NMB-CDC 株的双球菌的表面积比 MC58 株大 1.89 倍。据推测，在不改变外膜中锚定糖脂荚膜数量的情况下，表面积的增加会导致荚膜更加稀疏，表面疏水性增加。通过疏水性相互作用色谱法和微生物对溶剂的粘附试验，显示 NMB-CDC 株比 MC58 株更具疏水性。总之，NMB-CDC 株对细胞系的粘附水平提高与细菌细胞表面和表面疏水性增加有关。本研究表明，脑膜炎奈瑟菌的细菌细胞表面积和表面疏水性存在多样性，这影响了脑膜炎奈瑟菌发病机制的步骤。
