Abstract
Rogosa broth, without its salt supplement and dissolved in deionized water, was adapted for the selective isolation and enumeration of enterococci. This medium supported good growth of enterococci, but it suppressed growth of other lactic acid bacteria. The sensitivity and specificity of the medium were tested after addition of various increasing concentrations of NaN3 against known strains of enterococci and other bacteria. Many strains of Streptococcus faecium showed low azide tolerance; optimal growth was obtained at a concentration of 0.01% NaN3, which totally or partially inhibited unrelated species of lactic acid bacteria. The selectivity of the medium was further increased by pH adjustment to 9.6. Carbonate and Tween 80 were added to overcome partial inhibition of enterococcal growth by the new combination of selective conditions. The final medium was evaluated in agar form in isolations from human and animal feces, polluted water, meat, and dairy products. Counts were obtained after 16 to 17 h of incubation at 37 C. The isolates satisfactorily conformed to the group characteristics of enterococci.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BURKWALL M. K., HARTMAN P. A. COMPARISON OF DIRECT PLATING MEDIA FOR THE ISOLATION AND ENUMERATION OF ENTEROCOCCI IN CERTAIN FROZEN FOODS. Appl Microbiol. 1964 Jan;12:18–23. doi: 10.1128/am.12.1.18-23.1964. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CHESBRO W. R., EVANS J. B. Factors affecting the growth of enterococci in highly alkaline media. J Bacteriol. 1959 Dec;78:858–862. doi: 10.1128/jb.78.6.858-862.1959. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DEIBEL R. H., LAKE D. E., NIVEN C. F., Jr PHYSIOLOGY OF THE ENTEROCOCCI AS RELATED TO THEIR TAXONOMY. J Bacteriol. 1963 Dec;86:1275–1282. doi: 10.1128/jb.86.6.1275-1282.1963. [DOI] [PMC free article] [PubMed] [Google Scholar]
- DEIBEL R. H. THE GROUP D STREPTOCOCCI. Bacteriol Rev. 1964 Sep;28:330–366. doi: 10.1128/br.28.3.330-366.1964. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Efthymiou C. J., Baccash P., Labombardi V. J., Epstein D. S. Improved isolation and differentiation of enterococci in cheese. Appl Microbiol. 1974 Sep;28(3):417–422. doi: 10.1128/am.28.3.417-422.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Efthymiou C. J., Joseph S. W. Difference between manganese ion requirements of pediococci and enterococci. J Bacteriol. 1972 Oct;112(1):627–628. doi: 10.1128/jb.112.1.627-628.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]