Molecular Evaluation of Resistance to Rifampicin and Isoniazid of Tuberculosis Patients by test “Genotype® MTBDR Plus” in Senegal

Abstract

Background: Multi Drug Resistant-Tuberculosis (MDR-TB) is a major public health problem in Senegal with less successful treatment of tuberculosis. There were 208 cases of MDR-TB in 2015 surveyed at 31 treatment sites by the National Program against Tuberculosis. Objectives: The aim of our study is to evaluate the prevalence of Mycobacterium tuberculosis isolates resistant to Rifampicin and Isoniazid and their associated resistance mutations in Senegalese patients. Materials and methods: MDR-TB was diagnosed by molecular testing (Genotype MTBDRplus Hain Life Science) among sputum samples obtained from 185 Senegalese TB patients and was defined as resistance to both Isoniazid (INH) and Rifampicin (RIF). Results: The sex-ratio M/W was of 2.2. The median age was 33.5 (8-72 years). Out of 185 positives samples for TB by microscopy, 95% (174/185) were Mycobacterium tuberculosis complex by Genotype MTBDRplus. The rate of TB-MDR+ in the total study population, treatment naïve, and previously treated was 64.94%, 46.25%, and 80.85%, RIF mono-resistance was 10.92%, 7.50%, and 13.83% and INH mono-resistance was 6.32%, 8.75%, and 4.26%. Our strains of Mycobacterium tuberculosis have mutations conferring resistance in the rpoB, katG and inhA genes among 75.86%, 68.69%, and 13.21% respectively. Conclusion: Our results demonstrate a high degree of resistance to Rifampicin and/or Isoniazid among Mycobacterium tuberculosis isolates from patients with a treatment history or contact with a patient with MDR TB which were rapidly detected with the use of Genotype MTBDRplus.