An evaluation of ELISA using recombinant p17 antigen for cattle brucellosis

Abstract

Brucellae are Gram-negative cocccobacilli, facultative intracellular bacterial pathogens of both humans and animals. Brucellosis is an important disease that is difficult to diagnose and treat that causes heavy economic losses and human suffering. Diagnosis of brucellosis plays a vital role for control and prevention of the disease. Lipopolysaccharide (LPS) based Enzyme Linked Immuno Sorbent Assay (ELISA) shows false positivity due to cross-reactivity with other gram-negative bacteria LPS. The present investigation was undertaken to assess the diagnostic potential of the recombinant P17 protein of Brucella. P17 gene of Brucella abortus (B. abortus) was amplified, cloned and subcloned into pQE 30 vector yielding high levels of protein expression. The purified recombinant P17 (rP17) protein was used to develop an indirect ELISA (i-ELISA) test for brucellosis. The rP17-ELISA was compared with RBPT (Rose Bengal Precipitation Test) and LPS-ELISA using 530 cattle sera. The concordance percentage and kappa statistics of P17-ELISA is greater in compression with LPS-ELISA. Relative sensitivity and relative specificity of P17-ELISA shows a positive trend with RBPT. The data suggest that P17-ELISA can be a useful method for Brucella diagnosis and recombinant P17 protein is a potential antigen for diagnosis of cattle brucellosis