Comparing IS6110-RFLP, PGRS-RFLP and IS6110-Mtb1/Mtb2 PCR methods for genotyping of Mycobacterium tuberculosis isolates

Aims: Tuberculosis (TB) is still an important disease in the world, especially in developing countries. Applying efficient and suitable methods for genotyping Mycobacterium tuberculosis (MTB) isolates is a crucial step for identifying the MTB transmission mode and controlling its subsequent outcomes. Considering the complexity of IS6110-RFLP and PGRS-RFLP methods for MTB classification, suggesting other simple but reliable techniques could be helpful in the MTB studies, especially in low-income countries.

Methods and results: This study aimed to evaluate the capabilities of three methods for genotyping MTB isolates collected from Iran through comparing our previously published results for IS6110-RFLP and PGRS-RFLP methods and current results obtained from IS6110-Mtb1/Mtb2 PCR technique. A strong concordance was observed between the results of clustering by three techniques. Calculated Kendall's Tau concordance value for correlation of IS6110-RFLP and IS6110-Mtb1/Mtb2 PCR, for IS6110-RFLP and PGRS-RFLP, and for IS6110-Mtb1/Mtb2 PCR and PGRS-RFLP techniques was equal to 0·943, 0·898 and 0·85 respectively.

Conclusions: A strong correlation between IS6110-Mtb1/Mtb2 PCR, and IS6110-RFLP and PGRS-RFLP methods was observed and therefore IS6110-Mtb1/Mtb2 PCR discriminates MTBs capably.

Significance and impact of the study: The study showed that IS6110-Mtb1/Mtb2 PCR, which is a simple and economical MTB genotyping approach, could be a more appropriate method to be applied in the low-budget research programmes.