To date, most serodiagnostic methods for brucellosis screening are based on antibodies against lipopolysaccharides of Brucella spp. However, this approach has the drawback of yielding false-positive results due to cross-reactivity with lipopolysaccharides of other related pathogens, especially Yersinia enterocolitica O:9. In this study, Brucella abortus AspC was cloned and expressed by PCR amplification into a pCold TF expression system to obtain recombinant AspC (rAspC). The immunogenicity of rAspC was confirmed by western blotting of Brucella-positive bovine serum. rAspC-based ELISA was performed to determine whether rAspC could be used in the serodiagnosis of bovine brucellosis. rAspC reacted strongly with anti-Brucella antibodies in positive sera in the tube agglutination test (TAT), but did not show strong reaction with most negative samples. In particular, the average OD492 value at the highest TAT titer showed a 1.4-fold increase with respect to the cutoff value. The accuracy, specificity, and sensitivity of rAspC were 71.88%, 78.33%, and 68%, respectively. These findings suggest that rAspC might be valuable for the serological diagnosis of bovine brucellosis.

Abstract
 INTRODUCTION
 MATERIALS AND METHODS
  Bacterial strains and growth condition
  Plasmid preparation
  Induction and purification of recombinant AspC (rAspC)
  SDS-PAGE and western blot assays
  TAT
  Indirect ELISA
  Statistical analysis
 RESULTS
  Purification and immunoreactivity of rAspC
  ELISA
 DISCUSSION
 REFERENCES

• Lauren Togonon Arayan(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Huynh Tan Hop(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Alisha Wehdnesday Bernardo Reyes(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University, Department of Veterinary Paraclinical Sciences, College of Veterinary Medicine, University of the Philippines Los Baños, College)
• Hannah Leah Tadeja Simborio(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• WonGi Min(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Hu Jang Lee(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Suk Kim(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University) Corresponding Author