A simple technique to assess bacterial attachment to metal surfaces

Abstract

There are several methods to assess bacterial adhesion to metal surfaces. Although these methods are sensitive, they are time consuming and need expensive chemicals and instruments. Hence, their use in assessing bacterial adhesion is limited. Therefore, a simple spectrophotometric method was developed to evaluate bacterial adhesion to metal surface. The method was calibrated using a bacterium Vibrio sp. and aluminium as a model organism and substratum, respectively. The method involves staining attached bacterial cells with crystal violet (0.5%). The crystal violet stain from the cells was eluted with an aqueous solution of sodium deoxycholate (2%). The absorbance of the crystal violet stain in deoxycholate was measured at 570 nm. The viable cell count of the attached bacterial cells was also measured using coventional plating technique. Relationship between the absorbance of crystal violet stained attached cells and the viable cell count of the attached bacteria was assessed using linear regression analysis. There was a highly significant relationship (r = 0.99 p is less than 0.001) between these two parameters. This suggest that the method can be used to assess bacterial adhesion to metal surfaces.