Objective: To determine whether there is a major difference in protein levels between isoniazid-resistant and susceptible M. tuberculosis strains.
Methods: The proteins extracted from 9 isoniazid-resistant M. tuberculosis strains and 7 isoniazid-susceptible M. tuberculosis strains were analyzed by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Protein spots remarkly increased in isoniazid-resistant M. tuberculosis strains were digested in gel by enzyme and the mass of generated peptides were measured by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). The data obtained from peptide mass fingerprinting were used in protein database search. These genes of all strains were sequenced.
Result: In all protein spot differences, 5 protein spots were upregulated in isoniazid-resistant strains and identified as Rv1446c, Rv3028c, Rv0491, Rv2971, and Rv2145 by (MALDI-TOF-MS).
Conclusion: These results suggest that the differentially expressed proteins from isoniazid-resistant strains might be used as potential immuno-diagnostic antigens and candidate novel drug targets against drug resistant tuberculosis.