Plasmids are common in natural bacterial communities, facilitating bacterial evolution via horizontal gene transfer. Bacterial species vary in their proficiency to host plasmids: whereas plasmids are stably maintained in some species regardless of selection for plasmid-encoded genes, in other species, even beneficial plasmids are rapidly lost. It is, however, unclear how this variation in host proficiency affects plasmid persistence in communities. Here, we test this using multispecies bacterial soil communities comprising species varying in their proficiency to host a large conjugative mercury resistance plasmid, pQBR103. The plasmid reached higher community-level abundance where beneficial and when introduced to the community in a more proficient host species. Proficient plasmid host species were also better able to disseminate the plasmid to a wider diversity of host species. These findings suggest that the dynamics of plasmids in natural bacterial communities depend not only upon the plasmid's attributes and the selective environment but also upon the proficiency of their host species.

中文翻译：

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原始宿主物种的熟练程度决定了群落水平的质粒动态

质粒在天然细菌群落中很常见，通过水平基因转移促进细菌进化。细菌物种对宿主质粒的熟练程度各不相同：尽管质粒在某些物种中保持稳定，无论选择质粒编码基因如何，但在其他物种中，即使是有益的质粒也会迅速丢失。然而，尚不清楚宿主熟练程度的这种变化如何影响社区中的质粒持久性。在这里，我们使用多物种细菌土壤群落来测试这一点，这些群落包括不同物种的宿主大型共轭汞抗性质粒 pQBR103。质粒在有益的地方以及在更熟练的宿主物种中引入群落时达到了更高的群落水平丰度。熟练的质粒宿主物种也能够更好地将质粒传播到更广泛的宿主物种中。这些发现表明，天然细菌群落中质粒的动态不仅取决于质粒的属性和选择性环境，还取决于其宿主物种的熟练程度。