DOI: 10.36347/sajb.2019.v07i11.010

Pages: 439-446

Background: Drug-resistant TB has become a public health problem. In 2017 WHO estimates that 3.6% of new TB cases and 17% of previously treated cases were multidrug-resistant (MDR-TB). However, 8.5% of people with MDR-TB had extensively drug-resistant TB (XDR-TB). Object: To evaluate the primary and secondary resistance of M.tuberculosis in TB patients and the resistance mutations. Materials and methods: 137TB-specimens are examined by the Seegene Anyplex™II MTB/MDR/XDR test. These patients are 45 new cases and 92 TB patients with treatment history. The Chi-square and Fisher tests allowed us to calculate p-values. When the p-value was less than 0.05 (significance), we estimated the odds ratio and their interval reliability at 95% to measure the risks of association. Results: The median age was 30 years. 95.6% of the strains were tuberculosis complex (MTBC) and 61.06% were MDR, of which 3.8% XDR. Mono-RIF were detected for 9.16% of patients, mono-INH in 4.58% and mono-FQ in 0.7% of strains. Strains of Mycobacterium tuberculosis harbored mutations conferring resistance to rifampicin, to isoniazid and fluoroquinolones: 70.2%, 63.3% 12.2% and 4.5% respectively at the rpoB, KatG, inhA and gyrA. We did not observe mutations in the rrs gene and its promoter region eis conferring resistance to injectable drugs (amikacin, kanamycin and capreomycin). Mono-resistance (RIF, INH), multi-resistance (MDR, XDR) and resistances mutations rpoB, KatG, InhA were significantly higher in patients with treatment history than in new cases. Conclusion: Our study shows that MDR-TB is high in patients with treatment or in contact with MDR patients and that XDR-TB is rare in Senegal.