Abstract
A commercially available selective group A streptococcal agar (ssA) was evaluated for the recovery of group A streptococci (GAS) in comparison with recovery from simultaneous cultures on conventional sheep blood agar (SBA). Both sets of plates were incubated in air, 5% CO2, and anaerobically for 48 h, with a first reading taken at 24 h. A total of 402 (67.0%) GAS were isolated from the 600 specimens that were submitted. Recovery of GAS was significantly greater after 48 h of incubation than after 24 h of incubation for each medium-atmosphere combination. After 48 h of incubation, the sensitivities of GAS detection obtained by each culture technique were as follows: ssA-anaerobic atmosphere, 98.5%; SBA-anaerobic atmosphere, 89.5%; ssA-CO2 atmosphere, 88.0%; SBA-air, 86.5%; SBA-CO2 atmosphere, 82.0%; and ssA-air, 74.6%. There were no cultures positive in air or CO2 which were not positive anaerobically on either medium. The increased sensitivity of detecting positive GAS cultures when incubation was done in an ssA-anaerobic atmosphere for 48 h uncovered patients truly infected with the organisms.
Full Text
The Full Text of this article is available as a PDF (191.5 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anhalt J. P., Heiter B. J., Naumovitz D. W., Bourbeau P. P. Comparison of three methods for detection of group A streptococci in throat swabs. J Clin Microbiol. 1992 Aug;30(8):2135–2138. doi: 10.1128/jcm.30.8.2135-2138.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bellon J., Weise B., Verschraegen G., De Meyere M. Selective streptococcal agar versus blood agar for detection of group A beta-hemolytic streptococci in patients with acute pharyngitis. J Clin Microbiol. 1991 Sep;29(9):2084–2085. doi: 10.1128/jcm.29.9.2084-2085.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carlson J. R., Merz W. G., Hansen B. E., Ruth S., Moore D. G. Improved recovery of group A beta-hemolytic streptococci with a new selective medium. J Clin Microbiol. 1985 Mar;21(3):307–309. doi: 10.1128/jcm.21.3.307-309.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Graham L., Jr, Meier F. A., Centor R. M., Garner B. K., Dalton H. P. Effect of medium and cultivation conditions on comparisons between latex agglutination and culture detection of group A streptococci. J Clin Microbiol. 1986 Oct;24(4):644–646. doi: 10.1128/jcm.24.4.644-646.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Huck W., Reed B. D., French T., Mitchell R. S. Comparison of the Directigen 1-2-3 Group A Strep Test with culture for detection of group A beta-hemolytic streptococci. J Clin Microbiol. 1989 Aug;27(8):1715–1718. doi: 10.1128/jcm.27.8.1715-1718.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kellogg J. A. Suitability of throat culture procedures for detection of group A streptococci and as reference standards for evaluation of streptococcal antigen detection kits. J Clin Microbiol. 1990 Feb;28(2):165–169. doi: 10.1128/jcm.28.2.165-169.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Roddey O. F., Clegg H. W., Clardy L. T., Martin E. S., Swetenburg R. L. Comparison of a latex agglutination test and four culture methods for identification of group A streptococci in a pediatric office laboratory. J Pediatr. 1986 Mar;108(3):347–351. doi: 10.1016/s0022-3476(86)80871-x. [DOI] [PubMed] [Google Scholar]
- Welch D. F., Hensel D., Pickett D., Johnson S. Comparative evaluation of selective and nonselective culture techniques for isolation of group A beta-hemolytic streptococci. Am J Clin Pathol. 1991 Apr;95(4):587–590. doi: 10.1093/ajcp/95.4.587. [DOI] [PubMed] [Google Scholar]