Rapid identification of mycobacteria from culture using acridinium-ester-labelled DNA probes.
OBJECTIVE
Our study used newly developed acridinium-ester-labelled DNA (AE-DNA) probes on 183 mycobacterial isolates, performing the tests on 12B Bactec vials and Loewenstein-Jensen (LJ) slants.


METHODS
The probe results were verified using the conventional method as a reference.


RESULTS
The probe for M. tuberculosis complex correctly identified 131 of 133 M. tuberculosis isolates, with two false negatives and no false positives, for a sensitivity of 98.5% and a specificity of 100%. The M. gordonae probe correctly identified 27 out of 27 M. gordonae isolates, with no false negatives and one false positive, for a sensitivity of 100% and a specificity of 90.9%. One hundred sixty-eight of the 183 isolates were screened in accordance with an algorithm, designed primarily for the rapid detection and identification of M. tuberculosis.


CONCLUSIONS
The use of the algorithm considerably reduced detection time: M. tuberculosis strains were identified within 16.2 +/- 2.3 days, while identification by conventional method required 35.7 +/- 5.5 days. Probe testing resulted in a cost increase of 67.8%.
Galietti
F
F
Department of Pulmonary Disease and Pathophysiology, University of Turin, Italy.
Chirillo
M G
MG
Gulotta
C
C
Torchio
R
R
Daglio
C
C
Pozzi
E
E
D000465:Algorithms; D015342:DNA Probes; D005188:False Negative Reactions; D005189:False Positive Reactions; D009161:Mycobacterium / Q000302:isolation & purification*; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D009170:Nontuberculous Mycobacteria / Q000302:isolation & purification; D012680:Sensitivity and Specificity
D015342:DNA Probes