The difficulty of diagnosing active tuberculosis (TB) and lack of rapid drug susceptibility testing (DST) at the point of care remain critical obstacles to TB control. This report describes a high-intensity mycobacterium-specific- fluorophage (φ 2GFP10) that for the first time allows direct visualization of Mycobacterium tuberculosis in clinical sputum samples. Engineered features distinguishing φ 2GFP10 from previous reporter phages include an improved vector backbone with increased cloning capacity and superior expression of fluorescent reporter genes through use of an efficient phage promoter. φ 2GFP10 produces a 100-fold increase in fluorescence per cell compared to existing reporter phages. DST for isoniazid and oxofloxacin, carried out in cultured samples, was complete within 36 h. Use of φ 2GFP10 detected M. tuberculosis in clinical sputum samples collected from TB patients. DST for rifampin and kanamycin from sputum samples yielded results after 12 h of incubation with φ 2GFP10. Fluorophage φ 2GFP10 has potential for clinical development as a rapid, sensitive, and inexpensive point-of-care diagnostic tool for M. tuberculosis infection and for rapid DST.
ASJC Scopus subject areas
- Microbiology (medical)