Design and optimization of Dot-blot ELISA system using specific antigens for simple and rapid diagnosis of glanders

Glanders is one of the oldest contagious and dangerous zoonotic diseases manifesting ulcerative granulomatous lesions on the skin and mucous membranes. Early methods possessing desirable sensitivity and specificity is important to diagnose the disease considering the just only one case report and preventing disease by identification and eradication. The present study was aimed to design and optimize Dot-blot ELISA system using specific antigens for simple and rapid detection of glanders using equine sera samples. Burkholderia mallei strains were cultured in nutrient broth supplemented with glycerol 4%. Whole cell antigens of bacterial strains were precipitated by trichloroacetic acid (TCA) followed by sonication method. The optimum concentrations of antigen-antibody were determined by checkerboard titration. The nitrocellulose membrane was coated by antigen, then stopped by skimmed milk as a blocker. The suspicious equine serum was added to the membrane following HRP-conjugated antibody, the signals were detected by TMB as a substrate. 4 out of 90 sera samples were positive by Dot-blot ELISA. The specificity and sensitivity of the test were evaluated 96.62% and 100%, respectively. B. mallei culture and isolation from clinical specimens of the horses validated the test. Our study showed that the Dot-blot ELISA is specific and sensitive in glanders diagnosis and it seems to be practical and efficient test due to the rapid, easy interpretation without any special tools, cost-effective and also field-friendly.