Effect of surface treatments of titanium on amphotericin B-treated Candida albicans persister cells

Abstract

Although persister cells in Candida albicans biofilm may contribute to its increased resistance to antifungal drugs, little information is available on the formation of Candida persister cells on titanium surfaces. The effect of different surface treatments of Ti on persister cells was determined in the present study. Titanium discs were surface-treated by three different methods (Group A - polishing, Group B - sandblasting followed by acid-etching, and Group C - sandblasting alone). Persister cells of two C. albicans strains, namely ATCC 90028 and HK30Aa, in biofilm and planktonic states, were measured as the percentage of colony forming units remaining after 24 h incubation with various concentrations of amphotericin B. No persister cells were detected in the planktonic cultures. However, 1.5%, 0.1% and 2.4%C. albicans ATCC 90028 persister cells were detected at an AmB concentration of 64 μg ml(-1) in groups A, B and C, respectively; and 0.3%, 0.2% and 0.6% for groups A, B and C, respectively, for HK30Aa. Group C of C. albicans ATCC 90028 appeared to provide a surface relatively unfavourable for the development of persister cells (P < 0.01). Whether these results may have implications on the clinical performance of titanium implants warrants further investigation.