Selective and enhanced recovery of group A and B streptococci from throat cultures with sheep blood agar containing sulfamethoxazole and trimethoprim

B. A. Gunn, D. K. Ohashi, Charlotte A Gaydos, E. S. Holt

Research output: Contribution to journalArticle

Abstract

Sheep blood agar containing 23.75 μg of sulfamethoxazole and 1.25 μg of trimethoprim (SXT-BA) per ml was compared with conventional sheep blood agar (SBA) for isolating group A and B streptococci from throat cultures. This selective medium allowed much better recovery of group A and B streptococci and suppressed the growth of the normal flora, including 'viridans' streptococci. In an initial study of 700 throat cultures, SXT-BA recovered 42% more group A and 49% more group B streptococci than did SBA. When SXT-BA was introduced into the routine microbiology laboratory and used by a number of medical technologists, SXT-BA recovered 28% more group A and 37% more group B streptococci than did SBA. In addition, the selective medium inhibited 83% of the non-group A and B streptococci that were recovered by SBA.

Original languageEnglish (US)
Pages (from-to)650-655
Number of pages6
JournalJournal of Clinical Microbiology
Volume5
Issue number6
Publication statusPublished - 1977
Externally publishedYes

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ASJC Scopus subject areas

  • Microbiology
  • Microbiology (medical)

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