Tuberculosis drug Resistance Isolates from Pulmonary Tuberculosis Patients, Kassala State, Sudan

Abstract

Background: This study was conducted in Kassala Teaching Hospital, Kassala State, Sudan (January 2006–June 2008) to determine the rate of mycobacterium drug resistance to anti-tuberculous treatment and to explore the genotype of Mycobacterium tuberculosis resistant isolates using rpoB gene. Methods: 53 isolates of mycobacterium isolated from pulmonary tuberculosis (PTB) patients from Kassala State were subjected to drug susceptibility testing (DST) to anti-tuberculous drugs; 10 M. tuberculosis complex (MTBC) resistant isolates were subjected to polymerase chain reaction (PCR), and commercially the amplified DNA was sequenced. Results: DST detected resistance in 23/53 (43.39%) isolates, among which rifampicin had a high number of resistant isolates (13/23), followed by streptomycin (11/23), and multi-drug resistance was detected in 5 isolates. DNA sequence analysis of 10 MTBC-resistant isolates detected variations within and out- side the rifampicin resistant determining region (RRDR). Variation within RRDR was detected at positions 512 (AGC/ATC, Ser/Ile), and 528 (CGC/CTC, Arg/Leu). Outside the RRDR region variations were detected at positions 498 (GTG/GGG, Val/gly), 488 (ACA/ACC, Thr/ Thr), which is a silent mutation. Insertions were observed at positions 484, 496 (GTG/GTGA, CGG/CAGG, respectively). Deletion was observed at position 487 (ATC/_TC). Discussion and conclusion: This study revealed that high resistance to rifampicin was asso- ciated with various point mutations in and out of the RRDR of the rpoB gene. Molecular methods are needed for early detection of TB disease and drug resistance.