Department of Laboratory Medicine, Faculty of Medicine and Health, Örebro University, Örebro, Sweden.
New England Biolabs, Ipswich, MA, USA.
Sci Rep. 2021 Mar 18;11(1):6239. doi: 10.1038/s41598-021-85266-7.
A rising incidence of meningococcal serogroup W disease has been evident in many countries worldwide. Serogroup W isolates belonging to the sequence type (ST)-11 clonal complex have been associated with atypical symptoms and increased case fatality rates. The continued expansion of this clonal complex in the later part of the 2010s has been largely due to a shift from the so-called original UK strain to the 2013 strain. Here we used single-molecule real-time (SMRT) sequencing to determine the methylomes of the two major serogroup W strains belonging to ST-11 clonal complex. Five methylated motifs were identified in this study, and three of the motifs, namely 5'-GATC-3', 5'-GAAGG-3', 5'-GCGCGC-3', were found in all 13 isolates investigated. The results showed no strain-specific motifs or difference in active restriction modification systems between the two strains. Two phase variable methylases were identified and the enrichment or depletion of the methylation motifs generated by these methylases varied between the two strains. Results from this work give further insight into the low diversity of methylomes in highly related strains and encourage further research to decipher the role of regions with under- or overrepresented methylation motifs.
脑膜炎奈瑟菌血清群 W 疾病的发病率在世界范围内呈上升趋势。属于序列型（ST）-11 克隆复合体的血清群 W 分离株与非典型症状和更高的病死率有关。该克隆复合体在 21 世纪 10 年代后期的持续扩张，主要归因于所谓的原始英国菌株向 2013 年菌株的转变。在这里，我们使用单分子实时（SMRT）测序来确定属于 ST-11 克隆复合体的两种主要血清群 W 菌株的甲基组。本研究共鉴定出 5 个甲基化基序，其中 5'-GATC-3'、5'-GAAGG-3'和 5'-GCGCGC-3'三个基序存在于所有 13 株被调查的分离株中。结果表明，这两种菌株之间没有菌株特异性基序或活性限制修饰系统的差异。鉴定出两种相位可变甲基化酶，这些甲基化酶产生的甲基化基序在两种菌株之间的富集或耗尽情况有所不同。这项工作的结果进一步深入了解了高度相关菌株中甲基组的低多样性，并鼓励进一步研究来解码低甲基化和高甲基化基序区域的作用。
