Ma Xinyan, Wu Ziyan, Li Junpeng, Yang Yang
College of Veterinary Medicine, Yangzhou University, Yangzhou, 225009, People's Republic of China.
Jiangsu Co-Innovation Center for Important Animal Infectious Diseases and Zoonoses, and Joint Laboratory of International Cooperation on Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou, 225009, People's Republic of China.
Infect Drug Resist. 2024 Sep 17;17:4037-4053. doi: 10.2147/IDR.S485049. eCollection 2024.
Biofilms significantly contribute to the persistence and antibiotic resistance of infections. However, the regulatory mechanisms governing biofilm formation of remain not fully elucidated. This study aimed to investigate the function of the lineage-specific two-component system, , in biofilm regulation and pathogenicity.
Bioinformatic analysis was conducted to assess the prevalence of across various lineages and to examine its structural features. The impact of on pathogenicity was evaluated using in vivo mouse models, including skin abscess, bloodstream infection, and nasal colonization models. Crystal violet staining and confocal laser scanning microscopy were utilized to examine the impact of on biofilm formation. Mechanistic insights into -mediated biofilm regulation were investigated by quantifying polysaccharide intercellular adhesin (PIA) production, extracellular DNA (eDNA) release, autolysis assays, and RT-qPCR.
The prevalence of varied among different lineages, with notably low carriage rates in ST398 and ST59 lineages. Deletion of in NCTC8325 strain resulted in decreased susceptibility to β-lactam and glycopeptide antibiotics. Although did not significantly affect acute pathogenicity, the Δ mutant exhibited significantly reduced nasal colonization and biofilm-forming ability. Overexpression of in naturally -lacking strains (ST398 and ST59) enhanced biofilm formation, suggesting a lineage-independent effect. Phenotypic assays further revealed that the Δ mutant showed reduced PIA production, decreased eDNA release, and lower autolysis rates. RT-qPCR indicated significant downregulation of , and genes, along with upregulation of , whereas autolysis-related genes remained unchanged.
The two-component system positively regulates biofilm formation in a lineage-independent manner, primarily by modulating PIA synthesis via the operon. These findings provide new insights into the molecular mechanisms of biofilm formation in and highlight as a potential target for therapeutic strategies aimed at combating biofilm-associated infections.
生物膜显著促进感染的持续存在和抗生素耐药性。然而，关于生物膜形成的调控机制仍未完全阐明。本研究旨在探讨特定谱系的双组分系统在生物膜调节和致病性中的作用。
进行生物信息学分析，以评估在不同谱系中的流行情况并检查其结构特征。使用体内小鼠模型，包括皮肤脓肿、血流感染和鼻腔定植模型，评估对致病性的影响。利用结晶紫染色和共聚焦激光扫描显微镜检查对生物膜形成的影响。通过定量多糖细胞间黏附素（PIA）产生、细胞外DNA（eDNA）释放、自溶测定和RT-qPCR，对介导的生物膜调节机制进行深入研究。
在不同谱系中的流行情况各不相同，在ST398和ST59谱系中的携带率明显较低。NCTC8325菌株中的缺失导致对β-内酰胺和糖肽类抗生素的敏感性降低。虽然对急性致病性没有显著影响，但Δ突变体的鼻腔定植和生物膜形成能力显著降低。在天然缺乏的菌株（ST398和ST59）中过表达增强了生物膜形成，表明存在不依赖谱系的效应。表型分析进一步显示，Δ突变体的PIA产生减少、eDNA释放减少且自溶率降低。RT-qPCR表明、和基因显著下调，同时上调，而自溶相关基因保持不变。
双组分系统以不依赖谱系的方式正向调节生物膜形成，主要通过操纵子调节PIA合成。这些发现为生物膜形成的分子机制提供了新的见解，并突出了作为对抗生物膜相关感染的治疗策略的潜在靶点。
