Sharma Shikha, Chaudhry Vasvi, Kumar Sanjeet, Patil Prabhu B
Bacterial Genomics and Evolution Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, India.
Front Microbiol. 2018 Feb 27;9:333. doi: 10.3389/fmicb.2018.00333. eCollection 2018.
is a prominent commensal member of human skin microbiome and an emerging nosocomial pathogen, making it a good model organism to provide genomic insights, correlating its transition between commensalism and pathogenicity. While there are numerous studies to understand differences in commensal and pathogenic isolates, systematic efforts to understand variation and evolutionary pattern in multiple strains isolated from healthy individuals are lacking. In the present study, using whole genome sequencing and analysis, we report presence of diverse lineages of isolates in healthy individuals from two geographically diverse locations of India and North America. Further, there is distinct pattern in the distribution of candidate gene(s) for pathogenicity and commensalism. The pattern is not only reflected in lineages but is also based on geographic origin of the isolates. This is evident by the fact that North American isolates under this study are more genomically dynamic and harbor pathogenicity markers in higher frequency. On the other hand, isolates of Indian origin are less genomically dynamic, harbor less pathogenicity marker genes and possess two unique antimicrobial peptide gene clusters. This study provides a basis to understand the nature of selection pressure in a key human skin commensal bacterium with implications in its management as an opportunistic pathogen.
是人类皮肤微生物群中一种重要的共生成员，也是一种新出现的医院病原体，这使其成为一个很好的模式生物，可用于提供基因组见解，阐明其在共生与致病性之间的转变。虽然有许多研究旨在了解共生菌株和致病菌株之间的差异，但缺乏系统的努力来了解从健康个体分离出的多个菌株的变异和进化模式。在本研究中，我们使用全基因组测序和分析，报告了在印度和北美两个地理位置不同的地区的健康个体中存在多种不同谱系的分离株。此外，致病性和共生性候选基因的分布存在明显模式。这种模式不仅体现在谱系中，还基于分离株的地理来源。本研究中的北美分离株在基因组上更具动态性且携带致病性标记的频率更高，这一事实证明了这一点。另一方面，印度来源的分离株在基因组上动态性较低，携带的致病性标记基因较少，并拥有两个独特的抗菌肽基因簇。本研究为理解一种关键的人类皮肤共生细菌中的选择压力性质提供了基础，这对其作为机会性病原体的管理具有重要意义。
