Comparison of BP26, Omp25 and Omp31 and a Multiepitope-Based Fusion Protein in the Serological Detection of Canine Brucellosis

Background: Brucellosis is one of the most important zoonotic diseases in the world. Canine brucellosis, caused mainly by Brucella canis, is seriously neglected, and there is a lack of accurate diagnostic tools. Methods: In this study, to compare BP26, Omp25, Omp31 and a multiepitope-based fusion protein in the serological detection of canine brucellosis, using 34 brucellosis-positive dog sera and 62 negative control sera, the Brucella outer membrane proteins Omp31, BP26, Omp25 and a multiepitope-based fusion protein were evaluated by iELISA for their potential use as antigens in the serological diagnosis of canine brucellosis. Results: The results showed that the multiepitope-based fusion protein performed best in distinguishing brucellosis-positive and brucellosis-negative dog sera, with a positive predictive value (PPV) of 100% and a negative predictive value (NPV) of 98.41%. BP26 and Omp31 showed excellent sensitivity in detecting brucellosis-positive dog sera, but their cross reaction to sera infected with Vibrio parahaemolyticus and Listeria monocytogenes may hinder their application as diagnostic reagents. Omp25 lacked sufficient sensitivity and showed limited ability in distinguishing positive and negative dog sera. Conclusion: The multiepitope-based fusion protein can be used as an ideal antigen for serologically diagnosing canine brucellosis currently prevalent worldwide.