Rakitin Andrey L, Ermakova Alexandra Y, Beletsky Alexey V, Petrova Mayya, Mardanov Andrey V, Ravin Nikolai V
Research Center of Biotechnology of the Russian Academy of Sciences, Institute of Bioengineering, 119071 Moscow, Russia.
Institute of Molecular Genetics of National Research Centre "Kurchatov Institute", 123098 Moscow, Russia.
Biology (Basel). 2021 Sep 4;10(9):871. doi: 10.3390/biology10090871.
Microbial life can be supported at subzero temperatures in permafrost up to several million years old. Genome analysis of strains isolated from permafrost provides a unique opportunity to study microorganisms that have not previously come into contact with the human population. is a typical soil bacterium that has been increasingly reported as hospital pathogens associated with bacteremia. In order to identify the specific genetic characteristics of ancient permafrost-conserved strains of and their differences from present-day clinical isolates, we carried out a genome-wide analysis of five strains of isolated from permafrost aged from 15 thousand to 1.8 million years. Surprisingly, we did not identify chromosomal genetic determinants that distinguish permafrost strains from clinical isolates and strains from other natural habitats. Phylogenetic analysis based on whole genome sequences showed that permafrost strains do not form a separate cluster and some of them are most closely related to clinical isolates. The genomes of clinical and permafrost strains contain similar mobile elements and prophages, which indicates an intense horizontal transfer of genetic material. Comparison of plasmids of modern and permafrost strains showed that plasmids from the modern strains are enriched with antibiotic resistance genes, while the content of genes for resistance to heavy metals and arsenic is nearly the same. The thawing of permafrost caused by global warming could release new potentially pathogenic strains of .
在高达数百万年历史的永久冻土中，零下温度下可维持微生物生命。对从永久冻土中分离出的菌株进行基因组分析，为研究此前未与人类接触过的微生物提供了独特机会。[具体细菌名称]是一种典型的土壤细菌，越来越多地被报道为与菌血症相关的医院病原体。为了确定[具体细菌名称]古老的永久冻土保存菌株的特定遗传特征及其与当今临床分离株的差异，我们对从1.5万年至180万年历史的永久冻土中分离出的5株[具体细菌名称]进行了全基因组分析。令人惊讶的是，我们没有发现能区分永久冻土菌株与临床[具体细菌名称]分离株以及来自其他自然栖息地菌株的染色体遗传决定因素。基于全基因组序列的系统发育分析表明，永久冻土菌株并未形成一个单独的聚类，其中一些与临床分离株关系最为密切。临床和永久冻土菌株的基因组包含相似的移动元件和原噬菌体，这表明遗传物质存在强烈的水平转移。现代和永久冻土菌株质粒的比较表明，现代菌株的质粒富含抗生素抗性基因，而对重金属和砷的抗性基因含量几乎相同。全球变暖导致的永久冻土融化可能会释放出新的潜在致病性[具体细菌名称]菌株。
