The local bacterial isolate B stearothermophilus was selected based on its high sensitivity to antibiotics and rapid growth within 2hrs at high temperatures to detect the antibiotic residues in milk and milk products.

Results revealed that B stearothermophilus has abroad spectrum to verify the presence of a multitude antimicrobial substance in milk. However, apart from the specified sensitivities for penicillin G and Sulfadiazine, a substantial number of other antibiotics, sulfonamides and inhibitory substances can be detected at or close to the levels that are defined by the Maximum Residue Level.