Modified microbiological method for the screening of antibiotics in milk
| Autor: | Fred S. Yein, Terry J. Gilbertson, Prem S. Jaglan, Rhonda L. Mejeur |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Chromatography
medicine.drug_class Antibiotics Cephalosporin Biology Penicillinase biology.organism_classification Anti-Bacterial Agents Cephalosporins Agar plate Geobacillus stearothermophilus Milk Genetics medicine Animals Animal Science and Zoology Biological Assay Agar diffusion test beta-Lactamase Inhibitors Beta-Lactamase Inhibitors Ceftiofur Bacteria Food Science Antibacterial agent |
| Zdroj: | Journal of dairy science. 78(5) |
| ISSN: | 0022-0302 |
| Popis: | The Bacillus stearothermophilus disc assay is routinely used by the dairy industry to screen milk for antibiotic residues. Although the assay detects the presence of beta-lactam antibiotics, it does not distinguish cephalosporins from other beta-lactam antibiotics. In this study, the B. stearothermophilus disc assay was modified to allow it to distinguish parent ceftiofur from other antibiotics by incorporation of the enzymes penicillinase and cephalosporinase into the assay. The modified B. stearothermophilus disc assay involves determining the zone of inhibition of a sample on an agar plate after the plate was incubated at 65 degrees C for 2.5 to 3 h as well as determining the zone of inhibition after the sample was treated with penicillinase or cephalosporinase. Samples in which this zone diameter was19 mm andor = 25 mm were interpreted using the data from the primary assay. Samples with zone diameters25 mm must be diluted 2- to 10-fold and reassayed to obtain a zone diameter19 andor = 25 mm, for proper interpretation. Samples with zone diametersor = 16 mm andor = 19 mm must also be reassayed using dilute enzyme solutions for proper interpretation. When these modifications of the B. stearothermophilus disc assay are used, ceftiofur can be distinguished from ampicillin, amoxicillin, penicillin, cephapirin, cloxacillin, novobiocin, and pirlimycin for samples with zone diametersor = 16 mm. This assay cannot, however, separate ceftiofur from cefazolin.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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