The Veterinary Record, Vol 153, Issue 19, 588-591
Copyright © 2003 by British Veterinary Association

Evaluation of tetracycline, erythromycin, penicillin and streptomycin for decontaminating koala semen contaminated in vitro with chlamydiae

¹ School of Life Sciences, Queensland University of Technology, Brisbane, Australia
² School of Animal Studies, University of Queensland, Gatton, Australia

Semen from seven koalas was extended in a tris-citrate glucose diluent containing one of four antibiotics at different concentrations and then contaminated with a standard concentration of chlamydiae. These semen preparations were then tested for residual chlamydial viability by an in vitro cell culture assay, and any detrimental effect of the antibiotics on the motility and viability of the sperm was assessed. Penicillin at 25 iu/ml or more, erythromycin at 1000 µg/ml or more and tetracycline at 200 µg/ml or more were highly effective at rendering the chlamydiae non-viable, but streptomycin showed no antichlamydial activity. There was a significant reduction of the motility of spermatozoa extended in diluents containing erythromycin (P<0·05), but spermatozoa incubated with tetracycline up to concentrations of 200 µg/ml were not affected.