Comparison of four culture media for the isolation of Mycobacterium tuberculosis: a 2-year study

Four media, Lowenstein-Jensen, Middlebrook, Petragnani, and ribonucleic acid, were tested for comparative ability to detect Mycobacterium tuberculosis. Specimens used included sputum, urine, tissue, and gastric washings. Three types of comparison were used: (i) comparison derived from randomized specimens; (ii) comparison of cultures from newly diagnosed cases that had received no prior therapy; and (iii) comparison of cultures from specimens whose initial direct smears were negative. Overall, ribonucleic acid medium performed best, but the differences among the four media were small.