Modified oxidation-fermentation medium for detection of acid production from carbohydrates by Neisseria spp. and Branhamella catarrhalis

Abstract

A modified oxidation-fermentation medium was developed as a practical medium for highly sensitive and specific detection of acid production from carbohydrates by Neisseria spp. and Branhamella catarrhalis. A total of 756 strains representing 17 Neisseria spp. and Branhamella catarrhalis were tested in this medium, in which the protein concentration was reduced relative to the carbohydrate concentration, phenol red was substituted for bromthymol blue at a low concentration, and the initial pH was adjusted to 7.2. Sugar utilization patterns were consistent with published results and with other cultural and biochemical characteristics for these species. The reactions obtained using this medium were qualitatively better and more reproducible than those obtained in cystine-Trypticase agar (BBL Microbiology Systems, Cockeysville, Md.) medium.