[The effectiveness of some culture media with pyruvic acid bases for the isolation of mycobacteria from sputum].

The authors have studied the value of culture media based on pyruvic acid (the Dixon medium and an original medium called P.T.) in the isolation of mycobacteria from sputum, as compared with the Löwenstein-Jensen medium. The studies were carried out in two groups of patients: 1043 samples were collected from ambulatory patients and 1740 samples were collected from hospitalized patients. The superiority of the Dixon and of the P.T. media was confirmed by the increased percentage of positive cultures (11% and 20% respectively) as compared with the Löwenstein-Jensen medium. With these media it was possible to isolate mycobacteria 7--14 days earlier than with the other media. On the basis of the results obtained the authors recommend the use, in parallel, especially in those cases when the samples contain only a small number of bacteria, of the Löwenstein-Jensen medium and one of the media based on pyruvic acid.