title: [Mathematical model for the control and standardization of discs].
abstract: Analysis of tetracycline and erythromycin diagnostic discs manufactured in the USSR showed their conformity with the requirements of the USA Federal Register. Comparison of the antibiotic amounts extracting and diffusing from the discs showed that as an average 92 and 90 per cent of the extracted amounts of erythromycin and tetracycline respectively diffused into the agar. Subsequently, it is desirable that on control testing of the disc quality both the similarity of the antibiotic content in the discs and the real amount of the antibiotic diffusing into the agar should be considered. A statistically reliable correlation between the values of the growth inhibition zones around the discs with definite and constant amounts of erythromycin, tetracycline or oxacillin and different resistance levels for every staphylococcal strain was found. On the basis of such a control system it is possible to divide the staphyloccal strains into the groups with high, low and intermediate resistance levels to the above antibiotics. However, it is not possible to use such data for accurate calculation of the value of the minimum inhibitory concentration of unknown strains because of a high value of the main error.
mesh_terms: D004917:Erythromycin / Q000592:standards; D008433:Mathematics; D008826:Microbial Sensitivity Tests / Q000295:instrumentation / Q000592:standards*; D008956:Models, Chemical; D011786:Quality Control; D013752:Tetracycline / Q000592:standards; D014586:USSR; D014481:United States
chemical_list: D004917:Erythromycin; D013752:Tetracycline
vernacular_title: Matematicheskaia model' kontrolia i standartizatsii diskov