Genetic transfer among bacteria propels rapid resistance to antibiotics and decreased susceptibility to antiseptics. Staphylococcus aureus is a common culprit of hospital and community acquired infections, and S. aureus plasmids have been shown to carry a multitude of antimicrobial resistance genes. We previously identified a novel conjugative, multidrug resistance plasmid, pC02, from the clinical S. aureus isolate C02. This plasmid contained the chlorhexidine resistance gene qacA, and we were able to demonstrate that conjugative transfer of pC02 imparted decreased chlorhexidine susceptibility to recipient strains. In silico sequence analysis of pC02 suggested that the plasmid is part of the pWBG749-family of conjugative plasmids and that it contains three predicted origins of transfer (oriT), two of which we showed were functional and could mediate plasmid transfer. Furthermore, depending on which oriT was utilized, partial transfer of pC02 was consistently observed. To define the ability of the pC02 plasmid to utilize different oriT sequences, we examined the mobilization ability of nonconjugative plasmid variants that were engineered to contain a variety of oriT family inserts. The oriT-OTUNa family was transferred at the highest frequency; additional oriT families were also transferred but at lower frequencies. Plasmid stability was examined, and the copy number of pC02 was defined using droplet digital PCR (ddPCR). pC02 was stably maintained at approximately 4 copies per cell. Given the conjugative plasticity of pC02, we speculate that this plasmid could contribute to the spread of antimicrobial resistance across Staphylococcal strains and species.

中文翻译：

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金黄色葡萄球菌抗菌抗性质粒pCO2的结合和复制生物学。

细菌之间的基因转移推动了对抗生素的快速耐药性，并降低了对防腐剂的敏感性。金黄色葡萄球菌是医院和社区获得性感染的常见罪魁祸首，金黄色葡萄球菌质粒已显示出携带多种抗菌素耐药基因。我们先前从临床的金黄色葡萄球菌分离株CO2中鉴定了一种新型的偶联，耐多药质粒pCO2。该质粒包含洗必泰抗性基因qacA，我们能够证明pCO2的结合转移使洗必泰对受体菌株的敏感性降低。对pCO2的计算机序列分析表明，该质粒是结合质粒pWBG749家族的一部分，并且包含三个预测的转移起点（oriT），我们展示了其中两个是有功能的，可以介导质粒转移。此外，取决于使用哪种oriT，始终观察到pCO 2的部分转移。为了定义pCO 2质粒利用不同的oriT序列的能力，我们检查了被设计成包含多种oriT家族插入物的非缀合质粒变体的动员能力。oriT-OTUNa家族的转移频率最高。其他oriT家族也已转移，但频率较低。检查质粒的稳定性，并使用液滴数字PCR（ddPCR）定义pCO2的拷贝数。将pCO 2稳定地维持在每个细胞约4个拷贝。鉴于pCO2的共轭可塑性，