Proteomics of Culture Filtrate of Prevalent Strains: 2D-PAGE Map and MALDI-TOF/MS Analysis.

Although diverse efforts have been done to identify biomarkers for control of tuberculosis using laboratory strain H37Rv, the disease still poses a threat to mankind. There are many emerging strains, and proteomic profiling of these strains might be important to find out potential targets for diagnosis and/or prevention of tuberculosis. We evaluated the comparative proteomic profiling of culture filtrate (CF) proteins from prevalent strains (Central Asian or Delhi type; CAS1_Del, East African-Indian; EAI-3 and Beijing family) by 2D polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. As a result, we could identify 12 CF proteins (Rv0066c, Rv1310, Rv3375, Rv1415, Rv0567, Rv1886c, Rv3803c, Rv3804c, Rv2031c, Rv1038c, Rv2809, and Rv1911c), which were consistently increased in all prevalent strains, and interestingly, two CF proteins (Rv2809, Rv1911c) were identified with unknown functions. Consistent increased intensity of these proteins suggests their critical role for survival of prevalent isolates, and some of these proteins may also have potential as diagnostic and vaccine candidates for tuberculosis, which needs to be further explored by immunological analysis.