The Isolation of Probable 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.…”

“…Aliquots of samples from different parts of the body were plated on alkaline bromthymol blue lactose agar (Chapman et al, 1937) and on 7.5 per cent NaCI phenol red mannitol agar, and typical or suspicious colonies were tested for their power to coagulate plasma. Of a total of 208 cultures, 181 gave essentially similar results.…”

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

“…A further criticism is based on the fact that bromthymol-blue lactose agar does not entirely inhibit other bacteria. It does, however, inhibit "most other bacteria" (Chapman et al, 1937). Moreover, it inhibits most nonpathogenic staphylococci also.…”

“…Using bromthymol-blue lactose agar prepared in this laboratory, we (Chapman et al, 1937) found that 6.2 per cent of the transplants were nonpathogenic staphylococci and that 1.5 per cent of the pathogens had failed to grow on the medium. The Difco product has proved satisfactory also, as the foliowing analysis will show.…”

“…Since 1937 more than 7,000 samples have been tested routinely in this laboratory on Bacto bromthymol-blue lactose agar (Chapman et at., 1937) and Bacto phenol-red mannitol agar (Chapman, Lieb, and Curcio, 1938) for the isolation of plasma-coagulating staphylococci. Althpugh our impressions of the results obtained have been favorable, the publication of an adverse (but unsubstantiated) opinion by an investigator of recognized ability (Blair, 1939) made it imperative to undertake a critical and extensive analysis of the methods advocated.…”