Figure 1.
This study evaluated the biphasic medium (B–P medium) for the recovery of H37Rv and mycobacteria in clinical sputum specimens. A total of 1260 sputum specimens were decontaminated and cultured in the L-J slant and biphasic medium. Among them, the MGIT culture system was also used in 441 decontaminated specimens in addition to the presence of the L-J slant and biphasic medium.
Figure 2.
H37Rv culture in biphasic medium.
H37Rv ranging in concentration from 107 cfu to 1 cfu per vial were incubated in biphasic medium at 37°C for 2 weeks. The numbers of H37Rv were 107, 106, 105, 104, 103, 102, 10, 1, and 0 CFU/ml in tubes 1 through 8. Both white and black arrows indicate the locations of positive colonies of mycobacteria.
Figure 3.
Growth of H37Rv culture on and in different culture media.
For L-J (0.1), biphasic medium (0.1), and MGIT (0.1), a mean 0.1 ml of inocula were incubated. For biphasic medium (0.5) and MGIT (0.5), a mean 0.5 ml of inocula were incubated.
Table 1.
Characteristics of the 1192 participants.
Table 2.
Rates of recovery of mycobacteria by biphasic medium, L-J medium and MGIT 960 culture system.
Table 3.
Comparison of culture in biphasic medium to culture in L-J medium for detection of mycobacteria.
Table 4.
Culture results by method among specimens from each hospital.
Figure 4.
Box plot of median time required for growth of mycobacteria in each culture medium.
Box lengths indicate interquartile range. Horizontal lines in each box represent the median of the distribution. Whiskers extend from the normal minimum value to the normal maximum value. For L-J, biphasic medium (B–P), and MGIT, the results of 121 smear positive sputum specimens and 298 smear negative sputum specimens are shown.
Figure 5.
Growth of mycobacteria in L-J and biphasic medium scenarios with acid-fast bacilli (AFB) smear microscopy and status of the source respiratory specimen.
Results are shown for 830 AFB smear-negative respiratory specimens and 362 AFB smear-positive respiratory specimens that were found positive for M. tuberculosis by both L-J and biphasic medium (B–P). L-J, culture on L-J medium; B–P, culture in biphasic medium.
Table 5.
Growth time of mycobacteria in sputum culture and in different culture media.