Direct detection and identification of Mycobacterium tuberculosis in smear-positive sputum samples by fluorescence in situ hybridization (FISH) using peptide nucleic acid (PNA) probes.
METHODS
Peptidenucleic acid (PNA) probesdesigned for specific detection of mycobacteria of the Mycobacterium tuberculosis complex (MTC) and other non-tuberculous mycobacterium species (NTM) are shown to be able to penetrate the mycobacterial cell wall and subsequently hybridize in situ to complementary rRNA.


OBJECTIVE
To demonstrate the use of fluorescein-labelled PNA probes for detection and identification of M. tuberculosis in smear-positive sputum samples.


METHODS
The sensitivity and specificity of the PNA probes were investigated by fluorescence in situ hybridization (FISH) using cultures of mycobacterium strains representing species of the MTC and NTM, respectively.


RESULTS
M. tuberculosis strains were detected by FISH using specific fluorescein-labelled PNA probes directly in smear-positive sputum samples without changing the morphology of the cells.


CONCLUSIONS
PNA probes allow for rapid diagnosis of tuberculosis in smear-positive cases.
Stender
H
H
DAKO A/S, Glostrup, Denmark.
Mollerup
T A
TA
Lund
K
K
Petersen
K H
KH
Hongmanee
P
P
Godtfredsen
S E
SE
D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D015341:Nucleic Acid Probes; D020135:Peptide Nucleic Acids; D012680:Sensitivity and Specificity; D013183:Sputum / Q000382:microbiology*
D015341:Nucleic Acid Probes; D020135:Peptide Nucleic Acids