Identification and efficacy assessment of novel immunoprotective antigens from Mycoplasma synoviae for vaccine development.

Mycoplasma synoviae (MS) is a significant pathogen mentioned by the World Organisation for Animal Health (WOAH) and has caused substantial economic losses to the global poultry industry. The prevention and control strategies are primarily based on flock purification, antibiotic treatment, and vaccination. Given the high cost and extended timeline of flock purification, along with the growing antibiotic resistance, vaccination remains the most effective strategy for preventing MS transmission. This study employed pangenome analysis combined with reverse vaccinology (RV) to identify protective antigens against MS. At last, three proteins namely VY320 (elongation factor P), VY430 (50S ribosomal protein L6), and VY930 (YbhB/YbcL family Raf kinase inhibitor-like protein), were selected to assess their potential as candidate subunit vaccines. Furthermore, a lesion scoring method using a foot pad challenge model was established to evaluate the protective efficacy of the MS vaccine. The results indicated that the VY930 protein is an effective antigen and can activate strong humoral and cellular immunity responses in immunized flocks, superior to the inactivated vaccine. The screening strategy, evaluation methods, and related findings of this study may provide valuable insights into the prevention and control of MS.