Line probe assay for differentiation within Mycobacterium tuberculosis complex. Evaluation on clinical specimens and isolates including Mycobacterium pinnipedii.
A line probe assay (GenoType MTBC) was evaluated for species differentiation within the Mycobacterium tuberculosis complex (MTBC). We included 387 MTBC isolates, 43 IS6110 low-copy MTBC isolates, 28 clinical specimens with varying microscopy grade, and 30 isolates of non-tuberculous mycobacteria. The assay was 100% specific and identified all 387 isolates and 98% of all IS6110 low-copy strains in concordance with the gold standard. The 2% discrepancy was caused by 1 isolate showing a faint restriction fragment length polymorphism (RFLP) pattern. The assay could provide specifies identification in 13 of 19 (68%) microscopy-positive specimens and 0 of 9 microscopy-negative specimens. To our surprise, the probe for M. africanum subtype I reacted with M. pinnipedii. This cross-reaction has not previously been reported. The assay was rapid, easy to perform and directly applicable in highly smear-positive specimens. We predict that the assay will enable enhanced surveillance of species-specific treatment outcome, which may change treatment regimens.
Kjeldsen
Marianne Kirstine
MK
Section for Evolution and Microbiology, Department of Biology, Copenhagen University, Denmark.
Bek
Dorte
D
Rasmussen
Erik Michael
EM
Priemé
Anders
A
Thomsen
Vibeke Østergaard
VØ
D015373:Bacterial Typing Techniques / Q000379:methods*; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D009161:Mycobacterium / Q000145:classification* / Q000235:genetics; D009164:Mycobacterium Infections / Q000382:microbiology*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000379:methods*
D004269:DNA, Bacterial