Accessory Gene Regulator (agr) Allelic Variants in Cognate Staphylococcus aureus Strain Display Similar Phenotypes

作者：Li Tan, Yuyang Huang, Weilong Shang, Yi Yang, Huagang Peng, Zhen Hu, Yuting Wang, Yifan Rao, Qiwen Hu, Xiancai Rao, Xiaomei Hu, Ming Li, Kaisen Chen, Shu Li · 发表于：Frontiers in Microbiology · 年份：2022 · DOI：10.3389/fmicb.2022.700894 · 被引用次数：30 · 研究领域：Antimicrobial Resistance in Staphylococcus、Bacterial biofilms and quorum sensing、Biochemical and Structural Characterization

The a ccessory g ene r egulator ( agr ) quorum-sensing system is an important global regulatory system of Staphylococcus aureus and contributes to its pathogenicity. The S. aureus agr system is divided into four agr groups based on the amino acid polymorphisms of AgrB, AgrD, and AgrC. The agr activation is group-specific, resulting in variations in agr activity and pathogenicity among the four agr groups. Strains with divergent agr system always have different phenotypes. In the present report, we, respectively, exchanged the agr system of a certain S. aureus with other three agr alleles and assessed the corresponding phenotypes of these congenic strains. Replacement of the agr system led to significant variations in hemolytic activity, protein expression, and virulence gene expression comparing with that of the parental strain. Interestingly, we found that the biological characteristics of these agr congenic strains in the same strain background were highly similar to each other, and the allele-dependent differences of the agr systems were weakened. These findings indicate that the allele-dependent agr predilections of S. aureus are determined by some factors in addition to the polymorphisms of AgrB, AgrD, and AgrC. Future studies may reveal the novel mechanism to improve our understanding of the agr network.