Scanning electron microscopy (SEM) provides useful information on the shape, size, and localization within the biofilm of single bacteria as well as on the steps of biofilm formation process, on bacterial interactions, and on production of extracellular polymeric substances.
When biofilms are constituted by microbial species involved in health care-associated infections, information provided by SEM can be fruitfully used not only for basic researches but also for diagnostic purposes.
The protocols currently used in our laboratory for biofilm investigation by SEM are reported here. Particularly, the procedures to fix, dehydrate, and metalize in vitro-developed biofilms or ex vivo clinical specimens colonized by biofilm-growing microorganisms are described as well as the advantages of the observation of these samples by field emission scanning electron microscopy.
Scanning electron microscopy FESEM Biofilm ultrastructure Medical devices
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Authors are indebted with Dr. Maria Pia Balice, Director of the Clinical Chemistry and Microbiology Laboratory for kindly providing bacterial strains and explanted medical devices, and gratefully acknowledge Dr. Antonino Salvia, Director, and Dr. Angelo Rossini, Vice Director of the Medical Services of the Fondazione Santa Lucia in Rome for their advices on the clinical issues.
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