Abstract
Susceptibility of clinical isolates of Pseudomonas aeruginosa (29 isolates), Klebsiella species (54 isolates), Escherichia coli (28 isolates), Serratia marcescens (28 isolates), and Enterobacter species (29 isolates) to gentamicin, tobramycin, and amikacin was determined by the following three methods: commercial broth microdilution trays, standard agar dilution, and disk diffusion susceptibility. A total of 504 tests were performed by each method, and overall susceptibility or resistance determined by the broth microdilution method agreed with that determined by the agar dilution method in 92.7% of the tests, whereas results from the disk diffusion method agreed with those from the agar dilution method in 91.9% of the tests. The broth microdilution and disk diffusion methods agreed with each other 88.7% of the time. The broth microdilution system results varied from the agar dilution method results by more than one dilution in 121 of 504 determinations (24%); however, this altered susceptibility determinations in only 7.3% of the assays. E. coli isolates were found to be quantitatively more resistant to the aminoglycosides with the broth microdilution method than with the agar dilution method. In contrast, the broth microdilution method demonstrated P. aeruginosa to be quantitatively more susceptible to the aminoglycosides than when the results were obtained by the agar dilution method. The Micro-Media Systems method is economical, reliable, rapid, and simple to perform and yields quantitative minimum inhibitory concentrations.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Barry A. L., Jones R. N., Gavan T. L. Evaluation of the micro-media system for quantitative antimicrobial drug susceptibility testing: a collaborative study. Antimicrob Agents Chemother. 1978 Jan;13(1):61–69. doi: 10.1128/aac.13.1.61. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ericsson H. M., Sherris J. C. Antibiotic sensitivity testing. Report of an international collaborative study. Acta Pathol Microbiol Scand B Microbiol Immunol. 1971;217(Suppl):1+–1+. [PubMed] [Google Scholar]
- Feltham R. K., Power A. K., Pell P. A., Sneath P. A. A simple method for storage of bacteria at--76 degrees C. J Appl Bacteriol. 1978 Apr;44(2):313–316. doi: 10.1111/j.1365-2672.1978.tb00804.x. [DOI] [PubMed] [Google Scholar]
- Gerding D. N., Buxton A. E., Hughes R. A., Cleary P. P., Arbaczawski J., Stamm W. E. Nosocomial multiply resistant Klebsiella pneumoniae: epidemiology of an outbreak of apparent index case origin. Antimicrob Agents Chemother. 1979 Apr;15(4):608–615. doi: 10.1128/aac.15.4.608. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Reller L. B., Schoenknecht F. D., Kenny M. A., Sherris J. C. Antibiotic susceptibility testing of Pseudomonas aeruginosa: selection of a control strain and criteria for magnesium and calcium content in media. J Infect Dis. 1974 Nov;130(5):454–463. doi: 10.1093/infdis/130.5.454. [DOI] [PubMed] [Google Scholar]
- Washington J. A., 2nd, Yu P. K., Gavan T. L., Schoenknecht F. D., Thornsberry C. Interpretation of the disk diffusion susceptibility test for amikacin: report of a collaborative study. Antimicrob Agents Chemother. 1979 Mar;15(3):400–407. doi: 10.1128/aac.15.3.400. [DOI] [PMC free article] [PubMed] [Google Scholar]