Department of Analytical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.
Sci Rep. 2017 Oct 18;7(1):13462. doi: 10.1038/s41598-017-13857-4.
The versatile roles of toxin-antitoxin (TA) systems in bacterial physiology and pathogenesis have been investigated for more than three decades. Diverse TA loci in Bacteria and Archaea have been identified in genome-wide studies. The advent of massive parallel sequencing has substantially expanded the number of known bacterial genomic sequences over the last 5 years. In staphylococci, this has translated into an impressive increase from a few tens to a several thousands of available genomes, which has allowed us for the re-evalution of prior conclusions. In this study, we analysed the distribution of mazEF/pemIK family TA system operons in available staphylococcal genomes and their prevalence in mobile genetic elements. 10 novel m azEF/pemIK homologues were identified, each with a corresponding toxin that plays a potentially different and undetermined physiological role. A detailed characterisation of these TA systems would be exceptionally useful. Of particular interest are those associated with an SCCmec mobile genetic element (responsible for multidrug resistance transmission) or representing the joint horizontal transfer of TA systems and determinants of vancomycin resistance from enterococci. The involvement of TA systems in maintaining mobile genetic elements and the associations between novel mazEF/pemIK loci and those which carry drug resistance genes highlight their potential medical importance.
毒素-抗毒素（TA）系统在细菌生理和发病机制中的多功能作用已经研究了三十多年。在全基因组研究中已经鉴定出了细菌和古细菌中的多种 TA 基因座。大规模平行测序的出现极大地增加了过去 5 年中已知的细菌基因组序列数量。在葡萄球菌中，这导致了可用基因组数量从几十到几千的惊人增长，这使得我们能够重新评估先前的结论。在这项研究中，我们分析了可利用的葡萄球菌基因组中 mazEF/pemIK 家族 TA 系统操纵子的分布及其在移动遗传元件中的流行程度。鉴定出了 10 种新型 mazEF/pemIK 同源物，每种都有一个对应的毒素，这些毒素可能发挥不同的、尚未确定的生理作用。对这些 TA 系统进行详细的描述将非常有用。特别感兴趣的是那些与 SCCmec 移动遗传元件（负责多药耐药性的传播）相关的，或代表 TA 系统和肠球菌来源的万古霉素耐药决定因子的联合水平转移的系统。TA 系统在维持移动遗传元件中的作用以及新型 mazEF/pemIK 基因座与携带耐药基因的基因座之间的关联，突出了它们在医学上的潜在重要性。
