Development of new diagnostic devices for TB

Electronic versions

Dogfennau

  • Hanan Ali

Abstract

The main objective of the work was to develop an analytical method for the diagnosis of human and bovine TB+ and para-TB by finding the best Ag with high Ab binding signal. This was achieved in five parts. First, the synthesis of S,S-trans-alkene-methoxy mycolic acid (I) from M. tb was achieved successfully. This led to the synthesis of its glycolipid derivatives (TDM, TMM, GroMM, GMM and ArM). The second part was the analysis of a range of other synthetic Ags using TB+ and TB- human serum samples in ELISA assays. The best combinations of sensitivity and specificity were observed with TDM (160) (100 and 78%), ArM (179) (100 and 73%) and ArM (158) (100 and 86%). Combining the results from synthetic TDM (160), ArM (158) and GMM (180) gave 100 and 94% sensitivity and specificity. These represent very much better values than those reported with many recognised assays. The third part involved the serodiagnostic evaluation of the sugar esters of MA (I). High biological activity was observed with TDM (44). This also gave high distinction between TB+ and TB- human serum samples, the best combinations of sensitivity and specificity (100, 73%) and high area under the ROC curve (0.929) in contrast with other derivatives. The fourth part achived using four different sets of bovine serum samples, including one set of animals diagnosed with active bTB. Statistical analysis using multidimensional scaling (MDS) analysis and the Random Forest (RF) analysis showed that the ELISA assay can distinguish between different categories of serum sample. Combining the results from a set of Ags using mean decrease accuracy and mean decrease Gini illustrated that the synthetic Ags gave responses higher than the natural Ags. The best area under the ROC curves, sensitivity and specificity were observed with TDM (156) 0.959, 100 and 86 % respectively. Finally, a range of antigens were studied in ELISA assays using serum from cattle infected with MAP.

Details

Iaith wreiddiolSaesneg
Sefydliad dyfarnu
Goruchwylydd / Goruchwylwyr / Cynghorydd
  • Mark Baird (Goruchwylydd)
Dyddiad dyfarnuIon 2015