Ku, Tsun Sheng N; Athiappan Palanisamy, Suresh Kumar; Lee, Samuel A

Author(s)

Ku, Tsun Sheng N

Athiappan Palanisamy, Suresh Kumar

Lee, Samuel A

Publication Date

2010

Abstract

Despite growing data on antimicrobial lock therapy (ALT) in treating bacterial catheter-related bloodstream infections (CR-BSIs), ALT has not been established as a treatment option for CR-BSI caused by 'Candida albicans'. Based on our finding that high-dose doxycycline exhibited antifungal activity against mature 'C. albicans' biofilms, we evaluated additional antibacterial agents with Gram-positive activity [azithromycin, tigecycline (TIG) and vancomycin]. After screening these antibiotics, it was found that TIG had substantial antifungal activity against mature C. albicans biofilms. Therefore, TIG was assayed alone and in combination with fluconazole (FLC), amphotericin B (AmB) or caspofungin (CAS). TIG at 2048 μg/mL resulted in a >50% reduction in the growth of planktonic 'C. albicans' cells. TIG inhibited the formation of biofilms from 128 μg/mL. Against mature biofilms, 2048 μg/mL TIG reduced metabolic activity by 84.2%. Furthermore, addition of 512 μg/mL TIG to FLC at all concentrations tested provided additional reduction in the metabolic activity of mature biofilms. However, this was not superior to 512 μg/mL TIG alone. TIG at 512 μg/mL increased the antifungal effect of lower concentrations of AmB (0.03125-0.25 μg/mL), but at 0.03125 μg/mL and 0.0625 μg/mL this effect was not superior to 512 μg/mL TIG alone. TIG inhibited the antifungal effect of higher concentrations of AmB (≥2 μg/mL). TIG at 512 μg/mL inhibited the antifungal activity of CAS at lower concentrations (0.25'8 μg/mL). These data indicate that high-dose TIG is highly active in vitro against planktonic cells, forming biofilms and mature biofilms of 'C. albicans'.

Citation

International Journal of Antimicrobial Agents, 36(5), p. 441-446

ISSN

1872-7913

0924-8579

Link

https://hdl.handle.net/1959.11/10005

Publisher

Elsevier BV

Title

Susceptibility of 'Candida albicans' biofilms to azithromycin, tigecycline and vancomycin and the interaction between tigecycline and antifungals

Type of document

Journal Article

Entity Type

Publication

Author(s)	Ku, Tsun Sheng N Athiappan Palanisamy, Suresh Kumar Lee, Samuel A
Publication Date	2010
Abstract	Despite growing data on antimicrobial lock therapy (ALT) in treating bacterial catheter-related bloodstream infections (CR-BSIs), ALT has not been established as a treatment option for CR-BSI caused by 'Candida albicans'. Based on our finding that high-dose doxycycline exhibited antifungal activity against mature 'C. albicans' biofilms, we evaluated additional antibacterial agents with Gram-positive activity [azithromycin, tigecycline (TIG) and vancomycin]. After screening these antibiotics, it was found that TIG had substantial antifungal activity against mature C. albicans biofilms. Therefore, TIG was assayed alone and in combination with fluconazole (FLC), amphotericin B (AmB) or caspofungin (CAS). TIG at 2048 μg/mL resulted in a >50% reduction in the growth of planktonic 'C. albicans' cells. TIG inhibited the formation of biofilms from 128 μg/mL. Against mature biofilms, 2048 μg/mL TIG reduced metabolic activity by 84.2%. Furthermore, addition of 512 μg/mL TIG to FLC at all concentrations tested provided additional reduction in the metabolic activity of mature biofilms. However, this was not superior to 512 μg/mL TIG alone. TIG at 512 μg/mL increased the antifungal effect of lower concentrations of AmB (0.03125-0.25 μg/mL), but at 0.03125 μg/mL and 0.0625 μg/mL this effect was not superior to 512 μg/mL TIG alone. TIG inhibited the antifungal effect of higher concentrations of AmB (≥2 μg/mL). TIG at 512 μg/mL inhibited the antifungal activity of CAS at lower concentrations (0.25'8 μg/mL). These data indicate that high-dose TIG is highly active in vitro against planktonic cells, forming biofilms and mature biofilms of 'C. albicans'.
Citation	International Journal of Antimicrobial Agents, 36(5), p. 441-446
ISSN	1872-7913 0924-8579
Link	https://hdl.handle.net/1959.11/10005
Publisher	Elsevier BV
Title	Susceptibility of 'Candida albicans' biofilms to azithromycin, tigecycline and vancomycin and the interaction between tigecycline and antifungals
Type of document	Journal Article
Entity Type	Publication

Susceptibility of 'Candida albicans' biofilms to azithromycin, tigecycline and vancomycin and the interaction between tigecycline and antifungals

Files: