An improved microbiological procedure for detection of streptomycin residues in milk and animal tissues
Søgaard, H.
Acta Veterinaria Scandinavica 20(1): 38-44
1979
ISSN/ISBN: 0044-605X PMID: 108927 Document Number: 152523
Improved sensitivity of the Bacillus subtilis ATCC 6633 assay for streptomycin is based on the synergistic effect of penicillin added to the assay medium. Using Bacto Antibiotic Medium 5 without added penicillin, the lowest concn. of streptomycin sulphate that can be detected is 0.2 mu g/ml when steel cylinders are used and 0.4 mu g/ml with paper disks. When 0.1 IU penicillin is added/ml medium, and an inoculum of 1.0 X 107 B. subtilis spores/ml is used, the sensitivity of the assay is increased 8-fold, and 0.025 and 0.05 mu g streptomycin sulphate/ml can be detected, Enhancement of inhibition zones when penicillin is added to the assay medium can also indicate the presence of streptomycin in samples of milk or animal tissues.