背景:Schaalia物种主要在人类和其他动物的口腔微生物群中发现。通过参与生物膜形成,它们与各种感染有关,调节宿主反应,以及与其他微生物的相互作用。在这项研究中,先前表示为放线菌属的两个菌株。根据其整个基因组序列,发现它们是Schaalia属的新成员。
结果:全基因组测序显示两个菌株的基因组大小为2.3Mbp,GC含量为65.5%。分类位置的系统发育学分析显示,菌株NCTC9931和C24是Schaalia属中的不同物种。总体基因组相关性指数,包括数字DNA-DNA杂交(dDDH),和平均核苷酸/氨基酸同一性(ANI/AAI)证实这两个菌株是不同的物种,值低于物种边界阈值(dDDH<70%,ANI和AAI<95%)与最接近的菌株SchaaliatentolyticaNCTC9935T相比,Pangenome和直系同源分析强调了它们与现有类型菌株相比在基因特性和生物学功能上的差异。此外,基因组岛(GI)和毒力相关因子的鉴定表明了它们的遗传多样性和潜在的适应能力,以及对人类健康的潜在影响。值得注意的是,与菌株C24相比,菌株NCTC9931中的CRISPR-Cas系统强调了其适应性免疫机制。
结论:基于这些发现,菌株NCTC9931T(=ATCC17982T=DSM43331T=CIP104728T=CCUG18309T=NCTC14978T=CGMCC1.90328T)代表了一个新物种,名称为Schaaliadentphilasubsp。dentiphilasp.11月。subsp.11月。被提议,而菌株C24T(=NCTC14980T=CGMCC1.90329T)代表了一个独特的新亚种,名称为Schaaliadentphilasubsp。Denticola.subsp.11月。是提议的。这项研究丰富了我们对Schaalia物种基因组多样性的理解,并为进一步研究它们在口腔健康中的作用铺平了道路。
结论:这项研究揭示了两种Schaalia菌株,NCTC9931T和C24T,作为具有独特基因组特征的新型实体。扩展Schaalia属的分类学框架,这项研究为探索这些细菌的代谢复杂性和抗性模式提供了关键资源。这项工作是微生物分类学的基石,为临床诊断的重大进展铺平了道路。
BACKGROUND: Schaalia species are primarily found among the oral microbiota of humans and other animals. They have been associated with various infections through their involvement in biofilm formation, modulation of host responses, and interaction with other microorganisms. In this study, two strains previously indicated as Actinomyces spp. were found to be novel members of the genus Schaalia based on their whole genome sequences.
RESULTS: Whole-genome sequencing revealed both strains with a genome size of 2.3 Mbp and GC contents of 65.5%. Phylogenetics analysis for taxonomic placement revealed strains NCTC 9931 and C24 as distinct species within the genus Schaalia. Overall genome-relatedness indices including digital DNA-DNA hybridization (dDDH), and average nucleotide/amino acid identity (ANI/AAI) confirmed both strains as distinct species, with values below the species boundary thresholds (dDDH < 70%, and ANI and AAI < 95%) when compared to nearest type strain Schaalia odontolytica NCTC 9935 T. Pangenome and orthologous analyses highlighted their differences in gene properties and biological functions compared to existing type strains. Additionally, the identification of genomic islands (GIs) and virulence-associated factors indicated their genetic diversity and potential adaptive capabilities, as well as potential implications for human health. Notably, CRISPR-Cas systems in strain NCTC 9931 underscore its adaptive immune mechanisms compared to strain C24.
CONCLUSIONS: Based on these findings, strain NCTC 9931T (= ATCC 17982T = DSM 43331T = CIP 104728T = CCUG 18309T = NCTC 14978T = CGMCC 1.90328T) represents a novel species, for which the name Schaalia dentiphila subsp. dentiphila sp. nov. subsp. nov. is proposed, while strain C24T (= NCTC 14980T = CGMCC 1.90329T) represents a distinct novel subspecies, for which the name Schaalia dentiphila subsp. denticola. subsp. nov. is proposed. This study enriches our understanding of the genomic diversity of Schaalia species and paves the way for further investigations into their roles in oral health.
CONCLUSIONS: This research reveals two Schaalia strains, NCTC 9931 T and C24T, as novel entities with distinct genomic features. Expanding the taxonomic framework of the genus Schaalia, this study offers a critical resource for probing the metabolic intricacies and resistance patterns of these bacteria. This work stands as a cornerstone for microbial taxonomy, paving the way for significant advances in clinical diagnostics.