Drug Resistance in Tuberculous Spondylodiscitis: A Single-center Experience from a Tertiary Center in Western India

Background: This study of tuberculosis (TB) spondylodiscitis focuses on the epidemiology of the disease and drug resistance pattern to first and second-line anti-TB drugs in our setting. Study Design: This was a retrospective study including 261 culture-confirmed cases of TB spondylodiscitis. All specimens were cultured on Lowenstein–Jensen (LJ) medium and BACTEC MGIT liquid culture system. Drug susceptibility testing (DST) was performed on MGIT only. Results: Dorsal spine involvement was most common in our patient group. BACTEC MGIT method showed a distinct advantage over LJ medium in terms of increased culture yield (95.4% vs. 57.5%) and median time to positivity (15 days vs. 42 days). 11.1% of our patients had multidrug resistance (MDR) TB and additional 11.1% showed mono resistance to isoniazid. 72.4% of patients with MDR isolates showed worsening of disease on empirically initiated first-line regimen despite good adherence suggesting primary drug resistance, thereby underlining the importance of baseline cultures. 44.8% of patients with MDR disease showed a pre-extensive drug resistance (XDR) pattern of resistance but none had XDR disease. In patients with coexisting human immunodeficiency virus disease, high rate of culture positivity (89.2%) was seen along with high degree of drug resistance (24% MDR, 8% pre-XDR). Conclusion: Our study highlights the importance of performing universal and baseline culture and DST in view of effective management of drug-resistant spinal TB.