Evaluation of environmental scanning electron microscopy for analysis of Proteus mirabilis crystalline biofilms in situ on urinary catheters.
Proteus mirabilis is a common cause of catheter-associated urinary tract infections and frequently leads to blockage of catheters due to crystalline biofilm formation. Scanning electron microscopy (SEM) has proven to be a valuable tool in the study of these unusual biofilms, but entails laborious sample preparation that can introduce artefacts, undermining the investigation of biofilm development. In contrast, environmental scanning electron microscopy (ESEM) permits imaging of unprocessed, fully hydrated samples, which may provide much insight into the development of P. mirabilis biofilms. Here, we evaluate the utility of ESEM for the study of P. mirabilis crystalline biofilms in situ, on urinary catheters. In doing so, we compare this to commonly used conventional SEM approaches for sample preparation and imaging. Overall, ESEM provided excellent resolution of biofilms formed on urinary catheters and revealed structures not observed in standard SEM imaging or previously described in other studies of these biofilms. In addition, we show that energy-dispersive X-ray spectroscopy (EDS) may be employed in conjunction with ESEM to provide information regarding the elemental composition of crystalline structures and demonstrate the potential for ESEM in combination with EDS to constitute a useful tool in exploring the mechanisms underpinning crystalline biofilm formation.
School of Pharmacy and Biomolecular Sciences, University of Brighton, East Sussex, UK.
Nina
N
Holling
Cinzia
C
Dedi
Caroline E
CE
Jones
Joseph A
JA
Hawthorne
Geoffrey W
GW
Hanlon
Jonathan P
JP
Salvage
Bhavik A
BA
Patel
Lara M
LM
Barnes
Brian V
BV
Jones
D018441:Biofilms / Q000254:growth & development*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D011513:Proteus mirabilis / Q000502:physiology* / Q000648:ultrastructure*; D062885:Urinary Catheters / Q000382:microbiology*
Proteus mirabilis; catheter-associated urinary tract infection; crystalline biofilm; environmental scanning electron microscopy