Atomic force microscopy in biofilm study.

Biofilms have been classically visualized by Scanning Electron Microscopy (SEM). The complex operating procedure of SEM restricts its use in routine practice. There is a need of newer visualizing techniques for examining surfaces of biofilms, in particular under ambient conditions. We have presented the unique advantages of atomic force microscopy (AFM) in studying surfaces of biofilms through analyses of the height images obtained on biofilms of two gram positive and one gram negative bacteria, namely Staphylococcus aureus, Nocardia brasiliensis and Pseudomonas aeruginosa, respectively. Biofilm quality of the three different bacteria, ageing effects on Nocardia spp. biofilm surface and effects of the antibiotic ciprofloxacin at different doses on Staphylococcus and Pseudomonas biofilm surfaces have been investigated under ambient conditions and distinctive features have been observed.