Evaluation of Resazurin Micro Titer Assay Method for Detection of Vancomycin Sensitivity for Staphylococcus Aureus

Abstract

Background:
Resazurin reduction method was used firstly in industrial microbiology, mainly in the field of milk and milk product. Resazurin is a blue dye that does not fluoresce but becomes pink and fluoresces as it is reduced to resorufin by oxidoreductase within live cells without any biological effects. This study was conducted to introduce the Resazurin micro titter plate method as alternative susceptibility test, in this study a 100 pure staphylococcus strains were examined an against Vancomycin, the achieved results were compared with the gold standard disc diffusion susceptibility method.
Methods: In this study 100 Staphylococcus aureus strains collected from different infected area, were examined using Resazurin micro titter plate method, and Vancomycin antibiotics. The study was conducted in the research laboratory in the Omdurman Ahlia University, Khartoum state May 2017.
Results: This study showed statistically significant relationship between Resazurin micro titter plate method and disc diffusion susceptibility method with P. Value of 0.03.
Conclusion: Resazurin micro titter assay method was compared to disc diffusion susceptibility method and was achieved a predictive value of 96% and it’s may considered a valid susceptibility method.
Recommendation: Resazurin micro titter may introduce as a cheap antimicrobial susceptibility, furthermore; it will be a promising method and superior the old disc diffusion method because by it the MIC and MBC can be achieved. A large sample size is recommended.