Multidrug-resistant tuberculosis: rapid detection of resistance to rifampin and high or low levels of isoniazid in clinical specimens and isolates.
The aim of the present study was to evaluate a new improved multiplex polymerase chain reaction (PCR) hybridisation assay to detect multidrug-resistant tuberculosis. The assay, developed to detect rifampin (rpoB) and isoniazid (katG) gene mutations causing Mycobacterium tuberculosis resistance, was recently extended to include inhA gene mutations that code for low-level isoniazid resistance. Interpretable results were obtained in 115 isolates and in all smear-positive clinical specimens. Rifampin resistance was correctly identified in all specimens and in 20 of 21 (95%) multidrug-resistant isolates compared to BACTEC 460TB. Isoniazid resistance correlated in 18 of 22 (82%) specimens, in 31 of 31 (100%) high-level and 24 of 28 (86%) low-level isoniazid-resistant isolates. The assay was rapid, easy to perform and directly applicable in smear-positive specimens. We predict that the assay may be a useful tool to combat and prevent new cases of multi- and extensively drug-resistant tuberculosis.
International Reference Laboratory of Mycobacteriology and National Centre for Antimicrobials and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
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R
Vijdea
M
M
Stegger
A
A
Sosnovskaja
A B
AB
Andersen
V Ø
VØ
Thomsen
D
D
Bang
D000995:Antitubercular Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002374:Catalase / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D020125:Mutation, Missense; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics*; D010088:Oxidoreductases / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D012293:Rifampin / Q000494:pharmacology*; D012680:Sensitivity and Specificity; D018088:Tuberculosis, Multidrug-Resistant / Q000382:microbiology*
D000995:Antitubercular Agents; D001426:Bacterial Proteins; C505805:rpoB protein, Mycobacterium tuberculosis; D010088:Oxidoreductases; D002374:Catalase; C480353:katG protein, Mycobacterium tuberculosis; C085257:InhA protein, Mycobacterium; D012321:DNA-Directed RNA Polymerases; D007538:Isoniazid; D012293:Rifampin