In-vitro studies show pristinamycin to inhibit Staphylococci and Streptococci , including Erythromycin highly-resistant organisms, at a concentration of less than or equal to 0.78 mg/l.
To study Pristinamycin activity in vivo, mice infected IP with C. psittaci. Mortality in the control group was 70%. Three groups of mice received 25 mg/kg, 50 mg/kg and 100 mg/kg Pristinamycin respectively. The antibiotic was active in the 100 mg/kg dosage which is the therapeutic dosage.