FIELD: microbiology, medicine. SUBSTANCE: mycobacterial cells to be tested at density 10 mg wet weight/1 ml in 0.2-0.3 ml suspension is placed on standard paper disk with β-lactame antibiotic (concentration is about 10 mcg) and incubated for 22-24 h. Then disks are placed on Petri dishes where test-culture exhibiting sensitivity to this antibiotic is sown on nutrient agar. Activity of β-lactamase is determined by the change of test-culture growth inhibition zone as compared with control value. To assay an inhibition of β-lactamase reaction enzyme inhibitor is added at effective concentration to the incubated sample. EFFECT: improved method of assay. 2 cl, 1 dwg
