Improved reliability of the primary plate bacitracin test on throat cultures with sulfamethoxazole-trimethoprim blood agar plates

Abstract
The primary plate bacitracin differentiation disk susceptibility test identified 85% of group A streptococci from [human] throat cultures on SXT-BA [sulfamethoxazole-trimethoprim blood agar] (CO2) plates within 24 h, as compared to only 26% on a conventional sheep blood agar plate.