Identification of Proteins from Tuberculin Purified Protein Derivative (PPD) with Potential for TB Diagnosis Using Bioinformatics Analysis

Abstract

The PPD is widely used for diagnosis of bovine tuberculosis, however it lacks specificity and sensitivity, generally attributed the crossreactions with antigens shared by other Mycobacterium species. These highlight the necessity of better diagnostic tools to detect tuberculosis in cattle. We have identified proteins present in PPD preparations (avium and bovine PPD) by LC-MS/MS (Liquid Chromatography/Mass Spectrometry/Mass Spectrometry). A total of 169 proteins were identified. From these, four PPD proteins identified in bovine PPD and absent in avium PPD (Mb1961c, Mb2898, Mb2900 and Mb2965c) were select for bioinformatics analysis to identify an antigen with potential for TB diagnosis. We identified Mb1961c, a secreted protein, which has low identity proteins found in environmental mycobacteria. This protein could be used for the development of a diagnostic test or a synthetic PPD for bovine tuberculosis.