YycFG双组分信号转导系统调控葡萄球菌细胞壁合成、代谢及生物膜形成，PAS是组氨酸激酶YycG的胞外信号感应区域。本研究针对胞外PAS区域制备抗YycG-PAS单克隆抗体(YycG-PAS MAb)。免疫鉴定结果表明，YycG-PAS MAb可与重组YycG-PAS蛋白和表皮葡萄球菌菌体YycG蛋白结合，属于IgG2a亚型，效价为log 2¹⁵。YycG-PAS MAb(80 μg/ml)与表皮葡萄球菌RP62A菌株共培养24 h，对细菌生物膜形成的抑制率达46.5%，与mIgG(80 μg/mL)组相比有显著差异(P<0.05)。YycG-PAS MAb(80 μg/ml)与低浓度万古霉素(1 μg/ml)联用可增强对24 h细菌生物膜的抑制作用，抑制率由57.6%提高至93.0%(P<0.01)。YycG-PAS MAb对浮游状态表皮葡萄球菌的生长及存活无显著影响。本研究为YycG-PAS MAb在抗生物膜感染中的潜在应用价值奠定了一定基础。

Bacterial YycFG two-component signal transduction system plays a major role in controlling cell wall synthesis, metabolism and biofilm formation of Staphylococcus. The extracellular PAS domain of YycG histidine kinase can sense various environmental signals. Therefore, a monoclonal antibody targeting PAS domain of Staphylococcus epidermidis (S. epidermidis) was produced (YycG-PAS MAb). Enzyme-linked immunosorbent assay (ELISA) indicated that YycG-PAS MAb belonged to IgG2a subclass and antibody titer was log 2¹⁵. Western blotting suggested that YycG-PAS MAb had the ability to bind both recombinant YycG-PAS protein and protein extracted from cells. Further investigation exhibited inhibitory effect of YycG-PAS MAb (80 μg/ml) against biofilm formation after co-incubation with S. epidermidis and the inhibitory rate was 46.5%. The anti-biofilm activity of YycG-PAS MAb was improved when combined with low-concentration of vancomycin (1 μg/ml). The inhibitory rate was increased from 57.6% to 93.0% (P<0.01). No significant effects of YycG-PAS MAb on viability and growth of planktonic bacterial cells were observed. This study indicated that YycG-PAS MAb is a promising candidate antibody for biofilm-related infections.