Assessment of Candida albicans biofilm growth by laser speckle contrast imaging

Abstract

The study aimed to test laser speckle contrast imaging for fast and non-invasive assessment of ultrasound induced bactericidal effect on C. albicans biofilm. Low frequency sonication applied at 1.1 MPa peak negative pressure for 1 min reduced the number of viable C. albicans cells. The bactericidal effect was related to the spectral contrast decrease resulting from the standard deviation decrease within the speckle pattern as compared to the unchanged mean intensity. C. albicans biofilm recovered completely within 41 h after sonication. The recovery of biofilm was represented by increase of speckle contrast parameter. We foresee that speckle-based technique would be helpful for the efficacy assay of microbial biofilm inactivation.