Abstract:
Analysis of pneumococcal polysaccharides (PnPs) has been an arduous task, especially in similar serotypes. Pneumococci invades the host immune response by modulating capsule structure with small genetic changes making them indistinguishable from similar serotypes by conventional modes of analysis. The new serotype 24F causing invasive pneumococcal-resistant infection is an analytical challenge for its analysis as related serotypes 24A and 24B Ps share a common backbone. The difference in the branched chain which contains arabinitol and ribitol in 24F and 24B respectively are stereoisomers making their identification even more challenging. The composition analysis by GC-MS revealed distinct peaks for arabinitol in 24F and 24A Ps and ribitol in Pn 24B serotype polysaccharide. The mass spectral analysis confirmed their identification along with a heterologous cross-reactivity which confirmed anti-Pn-24F mAb reactive to Pn 24B than Pn 24A. The quantitative analysis of pneumococcal 24A, 24B and 24F using GC-MS showed sensitive analysis over the concentration range 3.125-200 μg/mL with regression coefficient >0.99 making ideal modality for the characterization, identification, and quantitation of pneumococcal 24A, 24B and 24F similar serotypes.
摘要:
分析肺炎球菌多糖(PnPs)是一项艰巨的任务,特别是在相似的血清型中。肺炎球菌通过小的遗传变化调节胶囊结构侵入宿主免疫反应,使其与常规分析模式的相似血清型无法区分。导致侵袭性肺炎球菌抗性感染的新血清型24F是其分析的分析挑战,因为相关血清型24A和24BP共享共同的骨架。分别在24F和24B中含有阿拉伯糖醇和核糖醇的支链的差异是立体异构体,使得它们的鉴定甚至更具挑战性。通过GC-MS进行的组成分析揭示了24F和24APs中的阿拉伯糖醇和Pn24B血清型多糖中的核糖醇的明显峰。质谱分析证实了它们的鉴定以及异源交叉反应性,这证实了抗Pn-24FmAb对Pn24B的反应性比Pn24A的反应性。肺炎球菌24A的定量分析,使用GC-MS的24B和24F显示了在3.125-200μg/mL浓度范围内的灵敏分析,回归系数>0.99,是表征的理想模式。identification,和肺炎球菌24A的定量,24B和24F相似血清型。