A Novel Reporter Phage To Detect Tuberculosis and Rifampin Resistance in a High-HIV-Burden Population.
Improved diagnostics and drug susceptibility testing for Mycobacterium tuberculosis are urgently needed. We developed a more powerful mycobacteriophage (Φ(2)GFP10) with a fluorescent reporter. Fluorescence-activated cell sorting (FACS) allows for rapid enumeration of metabolically active bacilli after phage infection. We compared the reporter phage assay to GeneXpert MTB/RIF for detection of M. tuberculosis and rifampin (RIF) resistance in sputum. Patients suspected to have tuberculosis were prospectively enrolled in Durban, South Africa. Sputum was incubated with Φ(2)GFP10, in the presence and absence of RIF, and bacilli were enumerated using FACS. Sensitivity and specificity were compared to those of GeneXpert MTB/RIF with an M. tuberculosis culture as the reference standard. A total of 158 patients were prospectively enrolled. Overall sensitivity for M. tuberculosis was 95.90% (95% confidence interval (CI), 90.69% to 98.64%), and specificity was 83.33% (95% CI, 67.18% to 93.59%). In acid-fast bacillus (AFB)-negative sputum, sensitivity was 88.89% (95% CI, 73.92% to 96.82%), and specificity was 83.33% (95% CI, 67.18% to 93.59%). Sensitivity for RIF-resistant M. tuberculosis in AFB-negative sputum was 90.00% (95% CI, 55.46% to 98.34%), and specificity was 91.94% (95% CI, 82.16% to 97.30%). Compared to GeneXpert, the reporter phage was more sensitive in AFB smear-negative sputum, but specificity was lower. The Φ(2)GFP10 reporter phage showed high sensitivity for detection of M. tuberculosis and RIF resistance, including in AFB-negative sputum, and has the potential to improve phenotypic testing for complex drug resistance, paucibacillary sputum, response to treatment, and detection of mixed infection in clinical specimens.
Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University Medical Center, New York, New York, USA Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, New York, USA Centre for AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa mo2130@columbia.edu.
Max R
MR
O'Donnell
KwaZulu-Natal Research Institute for TB/HIV (K-RITH), Durban, South Africa.
Alexander
A
Pym
Albert Einstein College of Medicine, Department of Microbiology and Immunology, Bronx, New York, USA.
Paras
P
Jain
KwaZulu-Natal Research Institute for TB/HIV (K-RITH), Durban, South Africa.
Vanisha
V
Munsamy
Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University Medical Center, New York, New York, USA.
Allison
A
Wolf
KwaZulu-Natal Research Institute for TB/HIV (K-RITH), Durban, South Africa.
Farina
F
Karim
Albert Einstein College of Medicine, Department of Microbiology and Immunology, Bronx, New York, USA Howard Hughes Medical Institute, Chevy Chase, Maryland, USA.
William R
WR
Jacobs
Albert Einstein College of Medicine, Department of Microbiology and Immunology, Bronx, New York, USA.
Michelle H
MH
Larsen
D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000494:pharmacology*; D001431:Bacteriological Techniques / Q000379:methods*; D024881:Drug Resistance, Bacterial; D005260:Female; D005434:Flow Cytometry; D005453:Fluorescence; D005470:Fluorometry / Q000379:methods; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009160:Mycobacteriophages / Q000254:growth & development*; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000302:isolation & purification* / Q000821:virology; D012189:Retrospective Studies; D012293:Rifampin / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D013019:South Africa; D013183:Sputum / Q000382:microbiology; D013194:Staining and Labeling / Q000379:methods; D014376:Tuberculosis / Q000175:diagnosis*; D055815:Young Adult
D000995:Antitubercular Agents; D049452:Green Fluorescent Proteins; D012293:Rifampin