Monitoring Candida parapsilosis and Staphylococcus epidermidis Biofilms by a Combination of Scanning Electron Microscopy and Raman Spectroscopy

0497561 - ÚPT 2019 RIV CH eng J - Journal Article
Hrubanová, Kamila - Krzyžánek, Vladislav - Nebesářová, Jana - Růžička, F. - Pilát, Zdeněk - Samek, Ota
Monitoring Candida parapsilosis and Staphylococcus epidermidis Biofilms by a Combination of Scanning Electron Microscopy and Raman Spectroscopy.
Sensors. Roč. 18, č. 12 (2018), č. článku 4089. E-ISSN 1424-8220
R&D Projects: GA MŠMT(CZ) LO1212; GA MŠMT ED0017/01/01; GA MŠMT(CZ) LM2015062
Institutional support: RVO:68081731 ; RVO:60077344
Keywords : Raman spectroscopy * biofilm * sample preparation * scanning electron microscopy * cryo-SEM
OECD category: Microbiology; Genetics and heredity (medical genetics to be 3) (BC-A)
Impact factor: 3.031, year: 2018

The biofilm-forming microbial species Candida parapsilosis and Staphylococcus epidermidis have been recently linked to serious infections associated with implanted medical devices. We studied microbial biofilms by high resolution scanning electron microscopy (SEM), which allowed us to visualize the biofilm structure, including the distribution of cells inside the extracellular matrix and the areas of surface adhesion. We compared classical SEM (chemically fixed samples) with cryogenic SEM, which employs physical sample preparation based on plunging the sample into various liquid cryogens, as well as high-pressure freezing (HPF). For imaging the biofilm interior, we applied the freeze-fracture technique. In this study, we show that the different means of sample preparation have a fundamental influence on the observed biofilm structure. We complemented the SEM observations with Raman spectroscopic analysis, which allowed us to assess the time-dependent chemical composition changes of the biofilm in vivo. We identified the individual spectral peaks of the biomolecules present in the biofilm and we employed principal component analysis (PCA) to follow the temporal development of the chemical composition.
Permanent Link: http://hdl.handle.net/11104/0290115