Culture remains the cornerstone of diagnosis for pulmonary tuberculosis, but the fastidiousness ofMycobacterium tuberculosismay delay culture-based diagnosis for weeks. We evaluated the performance of real-time high-resolution imaging for the rapid detection ofM. tuberculosiscolonies growing on a solid medium. A total of 50 clinical specimens, including 42 sputum specimens, 4 stool specimens, 2 bronchoalveolar lavage fluid specimens, and 2 bronchial aspirate fluid specimens were prospectively inoculated into (i) a commercially available Middlebrook broth and evaluated for mycobacterial growth indirectly detected by measuring oxygen consumption (standard protocol) and (ii) a home-made solid medium incubated in an incubator featuring real-time high-resolution imaging of colonies (real-time protocol). Isolates were identified by Ziehl-Neelsen staining and matrix-assisted laser desorption ionization–time of flight mass spectrometry. Use of the standard protocol yielded 14/50 (28%)M. tuberculosisisolates, which is not significantly different from the 13/50 (26%)M. tuberculosisisolates found using the real-time protocol (P= 1.00 by Fisher's exact test), and the contamination rate of 1/50 (2%) was not significantly different from the contamination rate of 2/50 (4%) using the real-time protocol (P= 1.00). The real-time imaging protocol showed a 4.4-fold reduction in time to detection, 82 ± 54 h versus 360 ± 142 h (P< 0.05). These preliminary data give the proof of concept that real-time high-resolution imaging ofM. tuberculosiscolonies is a new technology that shortens the time to growth detection and the laboratory diagnosis of pulmonary tuberculosis.
Statistics of the sodium layer parameters at low geographic latitude and its impact on adaptive-optics sodium laser guide star characteristics
