RHA™ anti-Tylosin monoclonal antibody, clone TYL

Arthritis, which requires a lot of attention from the supervising veterinarian, occurs regularly in veal calves at 5 to 10 weeks after housing. In the period November 2014 - March 2015, 32 veal calves with clinical symptoms of arthritis (swollen, warm and painful joints) were investigated and scored. Arthrocentesis was performed for bacterial examination and a blood sample was collected to confirm the presence of Mycoplasma bovis (M. bovis) antibodies. Immediately after clinical examination, all calves were treated according to a protocol in which animals in one group were treated with tylosin combined with a non-steroid anti-inflammatory drug, and those in another were treated with Pyrogenium-compositum combined with an external lotion (Promotion). All patients were monitored for 28 days and scored for aspect and temperature of the joint, mobility, soreness, and overall condition and feed intake.

A specific polyclonal antibody was prepared based on a new hapten with stable structure. Based on this, an indirect competitive enzyme-linked immunosorbent assay (icELISA) was established for determination of tylosin residues in food and environmental samples. The experimental conditions were optimized as follows: the coating antigen and antibody were respectively diluted by 6000 times and 2000 times, and the competitive reaction time was 40 min. Under the optimized conditions, the method showed a detection limit of 0.07 ng mL(-1), an IC50 of 1.39 ng mL(-1) and a linear range of 0.17-11.0 ng mL(-1). The recoveries of spiked raw milk and water samples were ranged from 78.4% to 105.6%, with the RSDs of less than 15%. Good correlation between icELISA and HPLC method was obtained for spiked samples (R-2 = 0.97). This method was suitable for the determination of tylosin residues in milk and water samples.