RT Journal Article SR Electronic T1 A Comparison of Two Commercially Irradiated Trypticase Soy Agars Containing Lecithin and Polysorbate 80 JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 130 OP 134 VO 46 IS 4 A1 Marsik, F. A1 Fowler, j. YR 1992 UL http://journal.pda.org/content/46/4/130.abstract AB Gamma-radiation sterilized Trypticase Soy Agar containing lecithin and polysorbate 80 (TSA++) (Becton Dickinson Microbiology Systems, Cockeysville. MD) and irradiated TSA++ (Adams Scientific, West Warwick, RI) were tested by a quantitative spread plate method. Four bacteria Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 10145, Staphylococcus aureus ATCC 25923, Streptococcus pyogenes ATCC 19615 and the yeast Candida albicans ATCC 10231 were tested in two separate experiments using different lots of media. A strain of Aspergillus niger ATCC 16404, was tested by a qualitative streak plate method. The Becton Dickinson Microbiology Systems (BDMS) irradiated TSA++ overall recovered a greater number of organisms than the Adams Scientific TSA ++ in both experiments and allowed for the earlier recovery of S. pyogenes/ATCC 19615. The growth of A. niger ATCC 16404, was comparable on both media. Efficacy of the media to neutralize 1, 2 and 3% phenol as well as 0.001. 0.01 and 0.1% benzalkonium chloride (BC) solutions was done by a disk diffusion method using 2 gram-positive and 4 gram-negative bacteria. Both media showed complete neutralization of the 0.001 and 0.01% BC solutions and partial neutralization of the 0.1% BC solution. The BDMS TSA++ showed better neutralization of the 2 and 3% phenol solutions than the Adams Scientific TSA++. This data indicates that not all irradiated TSA ++ media perform in an equivalent manner.