Activity of spiramycin against chlamydia, in vitro and in vivo.

In-vitro and in-vivo studies were performed to assess the activity of spiramycin against chlamydiae. In tissue culture spiramycin exhibited very good activity against Chlamydia trachomatis but less against C. psittaci. C. psittaci was also studied in a mouse experimental model. There was 100% clinical cure of the mice with 50 mg/kg, demonstrating excellent in-vivo activity. The livers of mice recovering after therapy showed less chlamydial antigen than controls. These results show good in-vitro and in-vivo activity of spiramycin against chlamydiae, suggesting that clinical trials are warranted.