The Starvation Resistance and Biofilm Formation of Enterococcus faecalis in Coexistence with Candida albicans, Streptococcus gordonii, Actinomyces viscosus, or Lactobacillus acidophilus.
BACKGROUND
Enterococcus faecalis is the most frequently detected species in root canal-treated teeth, and it is able to survive under starvation conditions. However, persistent periapical disease is often caused by multispecies. The aim of this study was to explore the survival of E. faecalis in starvation conditions and biofilm formation with the 4 common pathogenic species.


METHODS
A dual-species model of Candida albicans, Streptococcus gordonii, Actinomyces viscosus, or Lactobacillus acidophilus in combination with E. faecalis was established and allowed to grow in phosphate-buffered saline for the examination of starvation survival. Cefuroxime sodium and vancomycin at a concentration of 100 mg/L were added into brain-heart infusion plate agar to count the 2 bacteria separately in the dual species. Scanning electron microscopy was used to observe the dual species and multiple species on the root canal dentin of bovine teeth for 48 hours. A confocal laser scanning microscope was used to show the 4 groups of dual-species biofilms on substrates with glass bottoms for 48 hours.


RESULTS
E. faecalis was more resistant to starvation in coexistence with C. albicans, S. gordonii, A. viscosus, or L. acidophilus, and S. gordonii was completely inhibited in coexistence with E. faecalis. The dual-species biofilm showed that E. faecalis formed thicker and denser biofilms on the root canal dentin and glass slides in coexistence with S. gordonii and A. viscosus than C. albicans and L. acidophilus.


CONCLUSIONS
The multispecies community is conducive to the resistance to starvation of E. faecalis and biofilm formation in root canals.
Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
Yan
Y
Gao
Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
Xiaoqiong
X
Jiang
Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
Dongjia
D
Lin
Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China.
Yanhuo
Y
Chen
Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China; Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China. Electronic address: t_z_c1977@163.com.
Zhongchun
Z
Tong
D016924:Actinomyces viscosus / Q000254:growth & development*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001431:Bacteriological Techniques; D018441:Biofilms / Q000254:growth & development*; D002176:Candida albicans / Q000254:growth & development*; D002417:Cattle; D015169:Colony Count, Microbial; D003786:Dental Pulp Cavity / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000254:growth & development*; D007779:Lactobacillus acidophilus / Q000254:growth & development*; D059013:Microbial Consortia; D050296:Microbial Viability; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D054773:Streptococcus gordonii / Q000254:growth & development*
D000900:Anti-Bacterial Agents
Biofilm; Enterococcus faecalis; dual species; starvation