Preparation of monoclonal antibodies against Bc48 and development of a rapid detection assay for infection with Babesia caballi in China.

This study summarizes the creation of monoclonal antibodies against a local strain of the Bc48 gene of B. caballi, a cause of equine piroplasmosis, and the development of a rapid detection test. This test outperformed a comparable commercial ELISA kit test, carrying implications for rapid, efficient diagnosis of B. caballi in horses in the Xinjiang area.

Monoclonal Antibodies Production

• Babesia caballi is a parasite that causes economic harm to the horse industry in China, particularly in the Xinjiang Province, by inducing a disease called equine piroplasmosis.
• Monoclonal antibodies (mAbs) for the Bc48 gene of B. caball were developed, specific to local strains in the Xinjiang area.
• The study describes the production and purification of recombinant Bc48 from Escherichia coli to serve as an immunogen.
• Immunization with the recombinant Bc48 resulted in the production of three distinct hybridoma cells (11F4, 1H2 and 7F4), capable of producing the desired mAbs.
• These antibodies were identified to have a potent reaction with recombinant Bc48 and cells transfected with the Bc48 gene.

Development of the ICT Assay

• An immunochromatographic (ICT) assay was designed using the recombinant Bc48 antigen and the monoclonal antibodies derived in the study.
• The assay was based on colloidal gold labelling, a technique widely used for its simplicity and reliability in rapid detection tests.
• The ICT assay exhibited high sensitivity and specificity for Babesia caballi and no cross-reaction to a similar pathogen, Theileria equi.

Validation of the ICT Assay

• Serum samples from 56 horses in Xinjiang were tested using the newly-developed ICT and a commercial ELISA kit for comparison.
• Results showed that 32 samples were identified as positive by the ICT assay and 33 as positive by the ELISA kit.
• The ICT assay results coincided with the ELISA kit results at a high rate of 98%.
• This result supports the potential of the ICT assay as an efficient diagnostic tool for detecting B. caballi infection in horses specifically in the Xinjiang region.

This study offers hope for improved testing and monitoring of equine piroplasmosis in China, helping to control and mitigate the economic losses associated with the disease in its horse industry.