Abstract
To perform microdilution antimicrobial susceptibility tests efficiently, broth dilutions of the antimicrobial drugs should be prepared in large batches and stored frozen until needed. Studies were carried out to document the stability of ampicillin, benzylpenicillin, carbenicillin, methicillin, oxacillin, nafcillin, and cephalothin in microdilution trays during storage at −20 and −60 C. No significant deterioration was noted after 21 days of storage, as detected by bioassay and by replicate minimal inhibitory concentration determinations with control organisms. No significant differences were noted moreover between trays stored for three weeks at −20 C and those stored at −60 C. The microdilution technique was found to be a highly reproducible method for quantitative determination of antimicrobial susceptibility.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bauer A. W., Kirby W. M., Sherris J. C., Turck M. Antibiotic susceptibility testing by a standardized single disk method. Am J Clin Pathol. 1966 Apr;45(4):493–496. [PubMed] [Google Scholar]
- Bennett J. V., Brodie J. L., Benner E. J., Kirby W. M. Simplified, accurate method for antibiotic assay of clinical specimens. Appl Microbiol. 1966 Mar;14(2):170–177. doi: 10.1128/am.14.2.170-177.1966. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gavan T. L., Town M. A. A microdilution method for antibiotic susceptibility testing: an evaluation. Am J Clin Pathol. 1970 Jun;53(6):880–885. doi: 10.1093/ajcp/53.6.880. [DOI] [PubMed] [Google Scholar]
- MacLowry J. D., Jaqua M. J., Selepak S. T. Detailed methodology and implementation of a semiautomated serial dilution microtechnique for antimicrobial susceptibility testing. Appl Microbiol. 1970 Jul;20(1):46–53. doi: 10.1128/am.20.1.46-53.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MacLowry J. D., Marsh H. H. Semiautomatic microtechnique for serial dilution-antibiotic sensitivity testing in the clinical laboratory. J Lab Clin Med. 1968 Oct;72(4):685–687. [PubMed] [Google Scholar]
- Tilton R. C., Lieberman L., Gerlach E. H. Microdilution antibiotic susceptibility test: examination of certain variables. Appl Microbiol. 1973 Nov;26(5):658–665. doi: 10.1128/am.26.5.658-665.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]