Division 3 Antibiotic medium

Different laboratories have used various formulations of antibiotic medium with success and laboratories referred to in Annex II will be able to offer advice for a particular country. High concentrations of antibiotics are required for faeces samples and a typical mixture is: 10 000 units/ml penicillin, 10 mg/ml streptomycin, 0,25 mg/ml gentamycin and 5 000 units/ml mycostatin in phosphate buffered saline (PBS) These levels can be reduced up to five-fold for tissues and tracheal swabs. For control of Chlamydia organisms, 50 mg/ml oxytetracycline may be added. It is imperative when making the medium that the pH is checked after the addition of the antibiotics and readjusted to pH 7,0-7,4.