Mycobacterium tuberculosis genotypes associated with drug resistance in Isolates from Sudan

Tuberculosis (TB) is still one of the deadliest infectious diseases worldwide, it is one of the leading disease causing morbidity and mortality in Sudan. However, little scientific information is available on the drug sensitivity profiles of the strains of Mycobacterium tuberculosis in Sudan. This study was conducted to detect the relation between drug resistance and specific genotyping. A total of 74 clinical isolates of M. tuberculosis from patients with pulmonary TB were used. The phenotypic drug susceptibility test was done for isolates in LJ media contain anti-tuberculosis drugs (Rifampicin, Isoniazid, Streptomycin and Ethambutol), Spoligotyping to detect 43 known spacers in the direct repeat locus was performed with a commercially available kit, according to the instructions supplied by the manufacturer (Isogen Bioscience B.V., Maarsen, Netherlands). Both sensitive and MDR isolates were spoligotyped. Results were compared with the SITVIT Database4 (spolDB4.0 - Institut Pasteur, Guadeloupe). Phenotypically, 12.2% of the 74 tested isolates were drugs sensitive while 87.8% of them were multi-drug resistant (MDR).The spoligotype patterns of (90.5%) of isolates had patterns that matched those in the database while (9.5%) of isolates were defined as orphans. 15 different patterns were identified. The predominant were spoligotype international type (SIT) 54 and SIT25, each consisting of 43 and 7 isolates, respectively. The most of MDR M.tb isolates belong to SIT54 spoligotype pattern (58.8%). In conclusion, the SIT54 genotype was prevalent in this study and results indicate that a higher percentage of drug-resistant isolates are belonging to this genotype