Backscattered electron imaging and electron backscattered diffraction in the study of bacterial attachment to titanium alloy structure

• Published in: Journal of microscopy (Oxford) Vol. 270; no. 1; pp. 53 - 63
• Main Authors: WANG, ANQI, JONES, IAN P., LANDINI, GABRIEL, MEI, JUNFA, TSE, YAU Y., LI, YUE X., KE, LINNAN, HUANG, YUANLI, LIU, LI, WANG, CHUNREN, SAMMONS, RACHEL L.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-04-2018
• Subjects: Adhesion; Aluminum; Bacteria; Bacteria adhesion; Boundaries; Chemical composition; Diffraction; E coli; Electron backscatter diffraction; Electron imaging; Electron microscopy; Grain boundaries; grain boundary; Grain orientation; Heavy metals; Microorganisms; Microstructure; Scanning electron microscopy; Solid phases; Staphylococcus epidermidis; Statistical methods; Statistics; Strains (organisms); Streptococcus sanguinis; Substrates; Titanium; Titanium alloys; Titanium base alloys; Vanadium; electron microscopy; microstructure; Bacteria adhesion; chemical composition; grain boundary; grain orientation
• ISSN: 0022-2720; 1365-2818
• DOI: 10.1111/jmi.12649

Summary
The application of secondary electron (SE) imaging, backscattered electron imaging (BSE) and electron backscattered diffraction (EBSD) was investigated in this work to study the bacterial adhesion and proliferation on a commercially pure titanium (cp Ti) and a Ti6Al4V alloy (Ti 64) with respect to substrate microstructure and chemical composition. Adherence of Gram‐positive Staphylococcus epidermidis 11047 and Streptococcus sanguinis GW2, and Gram‐negative Serratia sp. NCIMB 40259 and Escherichia coli 10418 was compared on cp Ti, Ti 64, pure aluminium (Al) and vanadium (V). The substrate microstructure and the bacterial distribution on these metals were characterised using SE, BSE and EBSD imaging. It was observed that titanium alloy‐phase structure, grain boundaries and grain orientation did not influence bacterial adherence or proliferation at microscale. Adherence of all four strains was similar on cp Ti and Ti 64 surfaces whilst inhibited on pure Al. This work establishes a nondestructive and straight‐forward statistical method to analyse the relationship between microbial distribution and metal alloy structure.
Lay description
The application of scanning electron microscopy and its various modes was investigated in this work to study the bacterial adhesion and proliferation on polished pure titanium and its alloy (Ti6Al4V) to investigate the influence of substrate microstructure and chemical composition. Adherence of two Gram‐positive bacterial strains, and two Gram‐negative ones was compared and the bacterial distribution with respects to substrate microstructure quantified. It was observed that titanium alloy‐phase structure, grain boundaries and grain orientation did not influence bacterial adherence or proliferation at microscale. Adherence of all four strains was similar on the two titanium surfaces whilst inhibited on pure aluminium. This work establishes a nondestructive and straight‐forward statistical method to analyse the relationship between microbial distribution and metal alloy structure.