a Department of Dentistry, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
b Department of Oral Microbiology, College of Dentistry, Kyung Hee University, Seoul, Republic of Korea.
Virulence. 2022 Dec;13(1):1133-1145. doi: 10.1080/21505594.2022.2095718.
readily colonizes healthy dental biofilm and is associated with periodontal diseases. The viscous exopolysaccharide (EPS)-producing capability is known as a major virulence factor of 17 (Pi17). However, the inter-strain difference in regarding virulence-associated phenotype is not well studied. We compared virulence and whole genome sequences using five wild-type strains: ATCC 49046 (Pi49046), ATCC 15032 (Pi15032), ATCC 15033 (Pi15033), ATCC 25611 (Pi25611), and Pi17. Non-EPS producing Pi25611 was the least virulent in insect and mammalian models. Unexpectedly, Pi49046 did not produce viscous EPS but was the most virulent, followed by Pi17. Genomes of the five strains were quite similar but revealed subtle differences such as copy number variations and single nucleotide polymorphisms. Variations between strains were found in genes encoding glycosyltransferases and genes involved in the acquisition of carbohydrates and iron/haem. Based on these genetic variations, further analyses were performed. Phylogenetic and structural analyses discovered phosphoglycosyltransferases of Pi49046 and Pi17 have evolved to contain additional loops that may confer substrate specificity. Pi17, Pi15032, and Pi15033 displayed increased growth by various carbohydrates. Meanwhile, Pi49046 exhibited the highest activities for haemolysis and haem accumulation, as well as co-aggregation with harbouring type II, which is more tied to periodontitis than other types. Collectively, subtle genetic differences related to glycosylation and acquisition of carbohydrates and iron/haem may contribute to the diversity of virulence and phenotypic traits among strains. These variations may also reflect versatile strategies for within-host adaptation of
易于定殖于健康的牙齿生物膜，并与牙周病有关。粘性胞外多糖 (EPS) 产生能力是 17 (Pi17) 的主要毒力因子。然而，关于毒力相关表型的菌株间差异尚未得到很好的研究。我们使用 5 个野生型菌株比较了 Pi17 的毒力和全基因组序列：ATCC 49046 (Pi49046)、ATCC 15032 (Pi15032)、ATCC 15033 (Pi15033)、ATCC 25611 (Pi25611) 和 Pi17。不产生 EPS 的非 EPS 产生菌 Pi25611 在昆虫和哺乳动物模型中毒力最低。出乎意料的是，Pi49046 虽然不产生粘性 EPS，但却是最毒力的，其次是 Pi17。这 5 个菌株的基因组非常相似，但也存在细微差异，如拷贝数变异和单核苷酸多态性。在编码糖基转移酶的基因和参与碳水化合物和铁/血红素获取的基因中发现了菌株间的差异。基于这些遗传变异，进一步进行了分析。系统发育和结构分析发现，Pi49046 和 Pi17 的磷酸糖基转移酶进化出额外的环，可能赋予了它们底物特异性。Pi17、Pi15032 和 Pi15033 对各种碳水化合物的生长表现出增加。同时，Pi49046 对溶血和血红素积累以及与携带 Ⅱ 型的共聚集表现出最高的活性，这比其他 型更与牙周炎有关。总的来说，与糖基化以及碳水化合物和铁/血红素获取相关的细微遗传差异可能导致了菌株间毒力和表型特征的多样性。这些变化也可能反映了在宿主内适应的多种策略。
