Atomic force microscopy study of the structure–function relationships of the biofilm-formingbacterium Streptococcus mutans

Abstract

Atomic force microscopy (AFM) has garnered much interest in recent years for its ability toprobe the structure, function and cellular nanomechanics inherent to specific biologicalcells. In particular, we have used AFM to probe the important structure–functionrelationships of the bacterium Streptococcus mutans. S. mutans is the primary aetiologicalagent in human dental caries (tooth decay), and is of medical importance due to thevirulence properties of these cells in biofilm initiation and formation, leading to increasedtolerance to antibiotics. We have used AFM to characterize the unique surface structuresof distinct mutants of S. mutans. These mutations are located in specific genesthat encode surface proteins, thus using AFM we have resolved characteristicsurface features for mutant strains compared to the wild type. Ultimately, ourcharacterization of surface morphology has shown distinct differences in the localproperties displayed by various S. mutans strains on the nanoscale, which is imperativefor understanding the collective properties of these cells in biofilm formation.