Urakami Shogo, Hinou Hiroshi
Graduate School of Life Science, Hokkaido University, N21W11, Kita-Ku, Sapporo 001-0021, Japan.
Frontier Research Center for Advanced Material and Life Science, Faculty of Advanced Life Science, Hokkaido University, N21W11, Kita-Ku, Sapporo, 001-0021, Japan.
BBA Adv. 2024 Dec 17;7:100131. doi: 10.1016/j.bbadva.2024.100131. eCollection 2025.
is a zoonotic gram-negative bacterium with a wide range of hosts. Twenty-one classifications of O-antigens of , including their glyco-subtypes, have been reported and used as epidemiological indicators of health damage caused by this bacterium. In this study, we performed rapid identification of O-antigens using a modified MALDI O-antigen glycotyping method. By employing a DAN/DHB/K matrix, the O-antigen repeating units were detected as potassium adduct ions, facilitating the discrimination between hexoses, deoxyhexoses, and dideoxyhexoses, compared to the conventional matrix system with sodium ions. The branched dideoxyhexose of O-antigens was eliminated by the pretreatment or ionization process of MALDI glycotyping, and the repeating unit pattern reflecting the main-chain glycan sequence was given as the main spectrum. Of the four strains investigated, O2b and O3 polysaccharides with the same main-chain glycan sequence gave characteristic repeating unit pattern peaks, reflecting the difference in the position and stereochemistry of the branching dideoxyhexose. This study will accelerate the implementation of intraspecies classification targeting O-antigens in microbial identification techniques using MALDI-TOF MS.
是一种具有广泛宿主的人畜共患革兰氏阴性菌。已报道了该菌O抗原的21种分类，包括其糖亚型，并用作该菌所致健康损害的流行病学指标。在本研究中，我们使用改良的基质辅助激光解吸电离（MALDI）O抗原糖基分型方法对O抗原进行了快速鉴定。通过采用DAN/DHB/K基质，O抗原重复单元被检测为钾加合离子，与传统的钠离子基质系统相比，便于区分己糖、脱氧己糖和双脱氧己糖。O抗原的分支双脱氧己糖在MALDI糖基分型的预处理或电离过程中被消除，反映主链聚糖序列的重复单元模式作为主要谱图给出。在所研究的四株菌株中，具有相同主链聚糖序列的O2b和O3多糖给出了特征性的重复单元模式峰，反映了分支双脱氧己糖位置和立体化学的差异。本研究将加速在使用MALDI-TOF MS的微生物鉴定技术中针对O抗原进行种内分类的实施。
