CONTROL OF Neospora caninum IN SEMEN OF BULL

Abstract

The objective of the present study was to develop a diluent of bull semen efficient in the control of Neospora caninum. The antimicrobial test (experiment 1) -trimethoprim isolated (TRI) and associated with sulfadiazine (SDT) and sulfamethoxazole (SMT), clarithromycin (CLA), erythromycin (ERI), azithromycin (AZI) and clindamycin (CLI) - was performed using cell culture and evaluated for the presence of free tachyzoites and the cytopathic effect in the monolayer. The antimicrobials that proved effective in controlling the tachyzoites in vitro were used in the preparation of the diluent for the semen. Each antimicrobial was evaluated for sperm toxicity (experiment 2) with 8 groups (7 groups received an antibiotic in the diluent except for 1 group - control group). In relation to the morphological analysis, the SMT and AZI groups showed more acrosomal and tail defects. The SDT, SMT and AZI groups presented lower values of Average Path Velocity. The Straight-line Velocity was lower in the SMT and AZI groups and the Beat/cross Frequency was also lower in the CLI and AZI groups. The Curvilinear Velocity values of the SDT, SMT and CLA groups were lower. The SMT, ERI and AZI groups showed lower values of Total Motility and Progressive Motility. As for flow cytometry, the SDT, SMT and AZI groups presented higher percentages of acrosome reaction and damaged plasma membrane. The antibiotics can be added to the diluent of bull semen were clindamycin, clarithromycin and trimethoprim.