Background and objectives: Rapid diagnosis of Mycobacterium tuberculosis drug resistance is necessary to effectively control tuberculosis. Mutations in the 1400, 1401, 1483 positions of 16srRNA gene associated with resistance to amikacin. In this study using PCRRFLP method the presence of this mutation were investigated .The purpose of this study was to detect mutations in MDR strains of Mycobacterium tuberculosis which showed resistance to amikacin also. Material and Methods: Susceptibility testing against first and second –line drugs were performed on 100 culture positive specimens .Out of which 40 samples (based on their susceptibility results) were analyzed by PCR-RFLP using RRS1096 and RRS1539 primers to amplify a 460 bp region of the rrs gene. The PCR products were digested using Tai 1 and Dde1 restriction enzymes. Results: Using PCR-RFLP, 3 positive cultures (7.5% (showed resistant to amikacin and the remaining was susceptible. But, the number of amikacin resistant bacteria were 6 (15%) by proportional method. In addition, we found that the frequency of amikacin mutationin in rrs gene is more at 1400 or 1401 codon than 1483 . Disscusion and Conclusion: The PCR-RFLP method can be use as an additional method to detect resistance cases. Although to increase the sensitivity of PCR-RFLP we may need to study more number of codons in rrs gene. This method can provide rapid response for amikacin- resistant patients
