Acquisition of drug resistance in multidrug-resistant Mycobacterium tuberculosis during directly observed empiric retreatment with standardized regimens.
The risk of acquiring additional drug resistance in strains of multidrug-resistant tuberculosis (MDR-TB) during failure of empiric standardized retreatment regimens is poorly defined. We sought to estimate this risk by comparing drug susceptibility profiles and RFLP patterns of paired MDR-TB isolates collected from 27 patients before and after retreatment failure. Among 23 patients with paired isolates with concordant RFLP patterns, 19 (83%) had become resistant to at least one additional drug after failed retreatment. In this limited group of MDR-TB patients, acquisition of resistance was common during failure of empiric drug regimens. Further study is needed to confirm these findings.
Han
L L
LL
Massachusetts State Laboratory Institute, Boston, Massachusetts, USA. linda.han@state.ma.us
Sloutsky
A
A
Canales
R
R
Naroditskaya
V
V
Shin
S S
SS
Seung
K J
KJ
Timperi
R
R
Becerra
M C
MC
D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000494:pharmacology / Q000627:therapeutic use*; D023801:Directly Observed Therapy; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D019233:Retreatment; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy* / Q000382:microbiology
D000995:Antitubercular Agents