Detection of anti-Brucella antibodies in llama (Llama glama)

Seven llamas were immunized with killed Brucella abortus S1119.3 cells and bled sequentially, resulting in 64 samples. An eighth llama was kept as a negative control. In addition, 299 llama and 2075 alpaca sera, submitted for diagnostic testing, were included. Sera from all llamas were tested by the buffered antigen plate agglutination test, the complement fixation test, and the indirect enzyme immunoassays using smooth and rough lipopolysaccharides. A competitive enzyme immunoassay and fluorescence polarization assays were also performed. The sensitivity values for llama sera ranged from 92.2% to 100% and the specificity values from 89.6% to 100%. No alpacas were immunized. The specificity values for alpaca sera ranged from 94.8% to 100% specific although some sera gave an 'agglutination like' reaction after about 10 minutes of incubation. The complement fixation test could not be used, as 31% of the sera were anticomplementary and 4% were false positive.