Second-line drug resistance patterns among patients with multidrug-resistant tuberculosis of Gujarat, western India

Abstract

Background: Lack of laboratory diagnostic capacity is a crucial barrier preventing an effective response to early and appropriate case detection and treatment of multidrug-resistant tuberculosis (MDR-TB). To date, limited representative drug resistance data are available from India on second-line drug (SLD) resistance. Objectives: To study SLD resistance patterns in MDR-TB patients of Gujarat, western India. Materials and Methods: Antituberculosis drug susceptibility testing of 50 MDR-TB isolates particularly for SLDs, namely p-aminosalicylic acid, ciprofloxacin, amikacin, D-cycloserine, kanamycin, and ethionamide, was conducted on solid Lowenstein–Jensen medium using the 1% proportion sensitivity method. Results: Of 50 MDR-TB isolates tested, 24 (24/50, 48%) were found to be resistant to one or more SLDs. Of 50 MDR-TB isolates, 18 (18/50, 36%) showed resistance to ethionamide, 13 (13/50, 26%) to D-cycloserine, 11 (11/50, 22%) to ciprofloxacin, 7 (7/50, 14%) to kanamycin, 6 (6/50, 12%) to p-aminosalicylic acid, and 5 (5/50, 10%) to Amikacin. Conclusion: High levels of SLD resistance were found to be present in this study. There is an urgent need for more control and rational use of the widely available fluoroquinolones and other SLDs outside of the Revised National Tuberculosis Control Programme, by both the public and the private health sectors in India.