[Quantitative proteomic analysis of streptomycin resistant and sensitive clinical isolates of Mycobacterium tuberculosis].

Objective: To identify specific antigens related to streptomycin resistant (SMr) Mycobacterium tuberculosis.

Methods: Cellular proteins were extracted from SMr clinical isolate 01108, SM-sensitive clinical isolate 01105 and H37Rv. Differential expression proteins were identified with isobaric tags for relative and absolute quantitation (iTRAQ) combined with Nano LC-MS/MS technology.

Results: Approximately 194 and 146 differential expression proteins were identified in 01108 strain compared with the proteomic profiles of 01105 strain and H37Rv, respectively, and 121 proteins were identified in 01108 strain compared with the proteomic profiles of both 01105 strain and H37Rv. Identified proteins showed a pI (isoelectric point) variation between 3.74-12.48 and a molecular mass (M) range between 7.63 and 326.2 kDa. Differential expression proteins were mainly associated with metabolism (involved in intermediary metabolism, respiration, and lipid metabolism) and took part in catalysis and binding function. Seven ribosomal proteins (Rv0056, Rv0641, Rv0652, Rv0701, Rv1630, Rv2442c and Rv2785c) and seven proteins (the ratios > 1.20 or < 0.55) were commonly down-regulated in 01108 strain compared with both 01105 strain and H37Rv, i. e. the thiol peroxidase (Rv1932), acyl carrier protein dehydrogenase (Rv0824c), 30S ribosomal protein S15 (Rv2785c), acetone acid dehydrogenase E2 part (Rv2215), two-component transcriptional regulatory protein (Rv3133c) and Hypothetical protein (Rv2466e and Rv2626c).

Conclusion: Differential expression proteins were found in SMr strain compared with both SM-sensitive strain and H37Rv. Further studies are needed to assess the role of these differential expression proteins in SM resistance.