Volume 18, Number 3—March 2012
Letter
Discordance in Mycobacterium tuberculosis Rifampin Susceptibility
Table A1
AFB culture sequence of patient with discordant in Mycobacterium tuberculosis RF susceptibility*
Date | 2008 |
2009 |
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May 13 | Jun 2 | Dec 28 | Jan 31 | Feb 3 | Feb 24 | Aug 3 | Aug 4 | Aug 5 | Aug 19 | Sep 10 | Sep 11 | Oct 5 | Oct 7 | Oct 12 | ||
Specimen type | Sp × 3 | BAL | Sp × 3 | Sp | Sp × 2 | Sp × 3 | Blood | Sp | Sp | Sp | Blood | Sp | Sp | Sp | Sp | |
AFB smear (MTD) | – | 4+ (MTD+) | – | – | – | – | NA | 4+ (MTD+) | 4+ (MTD+) | 1+ | NA | 1+ (MTD+) | – | – | – | |
AFB culture | – | M. tuberculosis | – | M. avium-intraceullulare | – | – | M. tuberculosis | M. tuberculosis | M. tuberculosis | M. tuberculosis, M. avium-intraceullulare | – | – | – | – | – | |
Drug susceptibility (MGIT 960) | INH resistant (0.2 μg/mL); RIF susceptible; EMB susceptible; STR susceptible | INH resistant (0.1 μg/mL) RIF resistant EMB susceptible STR susceptible | INH resistant (0.2 μg/mL); RIF resistant; EMB susceptible; STR susceptible | |||||||||||||
Molecular resistance testing | Sequencing: inhA mutation associated with INH resistance | HAIN test: inhA point mutation; no rpoB mutation detected | CDC genotyping: inhA mutation associated with INH resistance + novel rpoB mutation (2009 Sep 9) | |||||||||||||
Drug treatment | INH/RIF/PZA/EMB initiated (2008 Jun 5) | 6 mos. RIF/PZA/ EMB completed (2008 Dec 12) | INH/RIF/PZA/ EMB, AMK, MXF initiated (2009 Aug 4) | AMK stopped (2009 Sep 1) | AMK resumed (2009 Sep 9) |
*RIF, rifampin; AFB, acid-fast bacilli; sp, sputum; BAL, bronchoalveolar lavage; MTD, Mycobacterium tuberculosis Direct Test (Gen-Probe, San Diego, CA, USA); –, negative; +, positive; NA, not applicable; MGIT, BACTEC Mycobacterium Growth Indicator Testing (MGIT 960; Becton Dickinson, Franklin Lakes, NJ, USA); INH, isoniazid; RIF, rifampin; EMB, ethambutol; INH, isoniazid; STR, streptomycin; HAIN, GenoType MTBDR plus line probe assay (HAIN Lifescience, Nehren, Germany); CDC, Centers for Disease Control and Prevention (Atlanta, GA, USA); PZA, pyrazinamide; AMK, amikacin; MXF, moxifloxacin.