Rapid drug susceptibility testing of mycobacteria by culture on a highly porous ceramic support
Ingham, C.J. ; Ayad, A.B. ; Nolsen, K. ; Mulder, B. - \ 2008
The International Journal of Tubercolosis and Lung Disease 12 (2008)6. - ISSN 1027-3719 - p. 645 - 650.
flow-cytometry - tuberculosis - assay - diagnosis - resistance - infection - anopore - growth - gene - tb
BACKGROUND: Phenotypic, culture-based methods for drug susceptibility testing (DST) of Mycobacterium tuberculosis are relatively simple and may be particularly appropriate for resource-limited settings where tuberculosis (TB) is most prevalent. However, these methods can be slow and generate significant amounts of infectious waste. Low-cost digital imaging and a unique porous ceramic support for cell culture (Anopore) may offer opportunities to improve this situation. OBJECTIVE: To testa rapid DST method based on fluorescence microscopy of mycobacteria grown for a few generations on Anopore. DESIGN: Mycobacteria were cultured with and without drugs, and the resulting microcolonies were heat-killed and stained with the fluorogenic dye Syto16. Micros-copy, image-capture with a charge-coupled device camera and digital processing were used to quantify the inhibition of growth by drugs. Rapid DST for rifampicin and isoniazid was performed for clinical isolates. RESULTS: Mycobacteria could be cultured, killed, stained and imaged on Anopore. For DST, the Anopore method gave an accurate result in 3 days. CONCLUSION: This is an unprecedented speed for culture-based DST for this group of organisms and results in minimal infectious waste (<20 000 colony forming units). Analysis of mycobacteria by fluorescence and electron microscopy on Anopore also opens up research possibilities.