The Reliability of Bromthymol-Blue Lactose Agar and Bacto Phenol-Red Mannitol Agar for the Isolation of Pathogenic Staphylococci

The Significance of Sodium Chloride in Studies of Staphylococci

“…Experiments with a small series of cultures indicated that the sensitivity and accuracy of the method are superior to those of methods previously described (e.g., Chapman, 1944c). Moreover, other bacteria are so completely inhibited that it is possible to use a considerably heavier inoculum than was possible in former methods, and enterococci, which are about the only organisms that cause interference on tellurite-treated (Chapman, 1944a) alkaline bromthymol blue lactose agar (Chapman et al, 1937) rarely grow on 7.5 per cent NaCl phenol red mannitol agar.…”

“…Therefore, differentiation between the reactions of pathogenic and nonpathogenic staphylococci is much sharper than it is by usual methods. Plasma was coagulated by 91 of the 100 staphylococci isolated in these experiments, as compared with 77 per cent by previous methods (Chapman, 1944c). The Stone reaction.…”