Safe Determination of Susceptibility of Mycobacterium tuberculosis to Antimycobacterial Agents by Flow Cytometry

AUTOR(ES)

Moore, Andrea V.

FONTE

American Society for Microbiology

RESUMO

We showed previously that susceptibility testing for Mycobacterium tuberculosis labeled with fluorescein diacetate could be accomplished rapidly by using flow cytometry. However, safety was a major concern because mycobacteria were not killed prior to flow cytometric analysis. In this study, we developed a biologically safe flow cytometric susceptibility test that depends on detection and enumeration of actively growing M. tuberculosis organisms in drug-free and antimycobacterial agent-containing medium. The susceptibilities of 17 clinical isolates of M. tuberculosis to ethambutol, isoniazid, and rifampin were tested by the agar proportion and flow cytometric methods. Subsequently, all flow cytometric susceptibility test samples were inactivated by exposure to paraformaldehyde before analysis with a flow cytometer. Agreement between the results from the two methods was 98%. In addition, the flow cytometric results were available 72 h after the initiation of testing. The flow cytometric susceptibility assay is safe, simple to perform, and more rapid than conventional test methods, such as the BACTEC system and the proportion method.

Documentos Relacionados

• Determination of in vitro susceptibility of Mycobacterium avium complex isolates to antimycobacterial agents by various methods.
• Rapid susceptibility testing of Mycobacterium tuberculosis (H37Ra) by flow cytometry.
• Flow cytometry as a tool to identify Mycobacterium tuberculosis interaction with the immune system and drug susceptibility
• Susceptibility of Mycobacterium tuberculosis to first-line antimycobacterial agents in a Brazilian hospital: assessing the utility of the tetrazolium (MTT) microplate assay
• Determination of in vitro susceptibility of Mycobacterium tuberculosis to cephalosporins by radiometric and conventional methods.