Abstract
Background: Extra-pulmonary tuberculosis (EPTB) is an important clinical problem in India as well as worldwide. The diagnosis of EPTB in its different clinical presentations remains a true challenge. The emergence and widespread dissemination of multidrug resistant (MDR) strains of Mycobacterium tuberculosis pose a serious threat to EPTB.
Objectives: To compare clinical pattern of MDRTB patients and genotypic pattern of these Mycobacterium tuberculosis isolates from EPTB cases.
Methods: A total of 789 specimens from patients of EPTB cases with varied presentation were studied. A total of 123 M. tuberculosis isolates recovered during the period Jan 2008-Dec2010 were tested for drug susceptibility against SHRE using the proportion method on Radiometric BACTEC. MDR isolates were sequenced in rpoB, katG and inhA for mutation analysis.
Results: 165 (20.7%) of 797 patients clinically suspected to have EPTB were BACTEC culture positive for mycobacteria. Out of 123/165 (74.5%) were M. tuberculosis cases, 94 (77%) were newly diagnosed and 29 (23%) retreated cases. Based on the phenotypic drug susceptibility testing results, 15 (12.1%) was MDR-TB. On basis of genotypic characterization of 15 MDR isolates, Rifampicin resistance related mutations in the rpoB gene were detected in 13/15 (86.7%). Isoniazid resistance-related mutations in the katG and inhA genes were detected in 12/15 (80%) of the MDR isolates.
Conclusions: Our study provides incidence of MDR-TB has been increasing in the clinical isolates of EPTB in Northern India. Genotypic pattern of MDR could be offer necessary information for improved TB control in the future.
- © 2011 ERS