Gold Nanoparticles Based Assay for Rapid Detection of Caseous Lymphadenitis in Sheep

Corynebacterium pseudotuberculosis is responsible for Caseous Lymphadenitis (CLA) disease in small ruminants (goats and sheep). The disease is difficult to control because antibiotic therapy is not effective. The disease is characterized by caseous abscess formation in the internal and external lymph nodes. Diagnosis is currently achieved only by routine bacteriological culture of pus obtained from external abscess. The lateral flow immunochromatographic test (LFIT) was prepared and evaluated for discover the present of Corynebacterium pseudotuberculosis in pus samples obtained from abscess in superficial lymph nodes. The minimal count of bacterial that gave positive LFIT was 102 CFU/ 0.1ml. About 100 pus samples from external lymph nodes were examined by the LFIT and the results were compared with conventional microbiological method. The obtained results demonstrate that the specificity was calculated and found to be 88.24%, while sensitivity was 90.36% and finally the accuracy was 90% of LFIT as compared to conventional microbiological method. These findings indicate that the developed LFIT test is a fast, simple and inexpensive field test of good specificity, sensitivity and accuracy that can be used to enhance Caseous Lymphadenitis control among sheep and goats.