Immunomodulatory Effects of Tulathromycin in Rabbits

Abstract

Tulathromycin is a new injectable macrolid antibiotic used for treating pulmonary disease. Therefore, the present work was aimed to study the effect of tulathromycin administration only or in a combination with vitamin C (immunomodatory agent) on immnomodulating, apoptotic effect and DNA of some immune cells. Moreover, to investigate its effect on serum antioxidant activity. Twenty-five apparently healthy rabbits were divided into 5 equal groups, the 1 st group was the control and the 2 nd was the vaccinated group with 1 mL/rabbit S.C "Pasteurella multocida vaccine". The 3 rd group injected with 17.5 mg/rabbit of vitamin C and 1 mL/rabbit S.C "Pasteurella multocida vaccine" while, the 4 th group was given 1 mL S.C/rabbit Pasteurella multocida vaccine and 2.5 mg/kg BW tulathromycin. The 5 th group was treated S.C with 17.5 mg/rabbit vitamin C, 1 mL Pasteurella multocida vaccine and 2.5 mg/kg BW tulathromycin. The results showed a significant inhibition of lymphocyte transformation at 3 rd day, phagocytic activity and lysozyme activity at 1 st , 2 nd and 3 rd day of vaccination in the 4 th group. Moreover, its total globulin level was significantly depressed at the 7 th and 14 th day with a depression of antibody titre against pasteurella till the 3 rd week post vaccination. Comet results revealed a significant increase of DNA damage % on the 3 rd and 7 th days post vaccination. DNA fragmentation of neutrophil was transiently occurred in the 3 rd and 7 th days post treatment. It was concluded that, Tulathromycin has a transient immunosuppressive and genotoxic effect, therefore it should be administered in a combination with Vit C to overcome its side effects.