High throughput screening to determine the antibacterial activity of Terminalia ferdinandiana (Kakadu plum): A proof of concept.

Different types of susceptibility tests are available to identify antimicrobial activity, including the disc agar diffusion and broth micro-dilution methods. In recent years, high throughput screening (HTS) methods have been considered and evaluated as an efficient method to rapidly monitor the antimicrobial potential of a wide range of plant products. The objective of this study was to test the ability of a 96-well plate reader as HTS method to evaluate the antimicrobial potential of extracts of Terminalia ferdinandiana (Kakadu plum). The main changes observed in the UV-VIS spectra of the bacteria samples were related to the biochemical and chemical compounds that might originate from the effect of the T. ferdinandiana extracts and the bacteria. Partial least squares discriminant analysis (PLS-DA) allowed the correct classification of samples according to the concentration of extract added to the culture (e.g. high, medium and low). The results of this study indicated that might be possible to record changes in the UV-VIS spectra associated with the interactions between bacteria and T. ferdinandiana extracts using a 96-well plate reader. The method was able to detect or differentiate between live and dead bacteria based on the UV-VIS spectra as a function of the addition of the T. ferdinandiana extracts.