Coexistence of Candida albicans and Enterococcus faecalis increases biofilm virulence and periapical lesions in rats

Abstract

The present study utilized an in vitro dual-species biofilm model and an in vivo rat post-treatment endodontic disease (PTED) model to investigate whether co-infection of Candida albicans and Enterococcus faecalis would aggravate periapical lesions. The results showed that co-culturing yielded a thicker and denser biofilm more tolerant to detrimental stresses compared with the mono-species biofilm, such as a starvation-alkalinity environment, mechanical shear force and bactericidal chemicals. Consistently, co-inoculation of E. faecalis and C. albicans significantly increased the extent of in vivo periapical lesions compared with mono-species infection. Specifically, coexistence of both microorganisms increased osteoclastic bone resorption and suppressed osteoblastic bone formation. The synergistic effects also up-regulated inflammatory cytokines including TNF-α and IL-6. In summary, coexistence of C. albicans and E. faecalis increased periapical lesions by enhanced biofilm virulence.

KEYWORDS:

• Candida albicans
• Enterococcus faecalis
• biofilms
• interspecies interaction
• post-treatment endodontic diseases

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Additional information

Funding

This work was supported by the Science and Technology Department of Sichuan Province under Grant 2020YJ0240, 2019YJ0074, 2018SZ0121 and the National Natural Science Foundation of China under Grant 81600874, 81771099.