Line probe assay (GenoType MTBDRplus) for first-line drug susceptibility testing detects mutations in which gene pair to identify isoniazid resistance?

• A rpoB and rrs genes
• B embB and ethA genes
• C pncA and gyrA genes
• D katG (S315T) and inhA promoter region mutations ✓

Explanation

The FL-LPA (GenoType MTBDRplus) detects isoniazid resistance through mutations in two genes: katG codon 315 (Ser→Thr, the most common, high-level INH resistance) and the inhA promoter region (low-level INH resistance, often associated with ethionamide cross-resistance). rpoB mutations indicate rifampicin resistance. embB detects ethambutol resistance; pncA detects pyrazinamide resistance; gyrA/gyrB detect fluoroquinolone resistance (detected on SL-LPA).

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.