[Expression of quorum-sensing related genes during Enterococcus faecalis biofilm formation].
OBJECTIVE
To investigate the relationship between the expression of the quorum-sensing related genes during Enterococcus faecalis(Ef) biofilm formation.


METHODS
Ef biofilms model was established in vitro and film formation process was observed by confocal laser scanning microscope at 6, 12, 24 and 48 hours respectively.Quantification of biofilms was achieved by staining with crystal violet.Real-time fluorescence quantitative PCR method was used to detect the expression of fsrB, gelE and sprE genes in the process of Ef biofilm formation.


RESULTS
A lot of live and dead bacteria unevenly distributed in Ef biofilm. The quantity of biofilms increased with time within 24 hours and was 0 h:0.00 ± 0.00, 6 h:1.09 ± 0.13, 12 h:2.10 ± 0.79, 24 h:3.30 ± 0.13, which was significantly different among the 4 time period(P < 0.05). The quantity of biofilm at 48 h(3.51 ± 0.01) increased slightly compared with 24 h(3.30 ± 0.13) , but did not show significant difference.Quantitative real-time PCR showed that the expression of quorum-sensing related fsrB increased with time within 24 hours and was 0 h:9.98 ± 0.46, 6 h:23.45 ± 1.13, 12 h:47.30 ± 2.49, 24 h: 331.30 ± 2.18, which was significantly different among the 4 time period(P < 0.05). The expression of gelE was 0 h: 6.54 ± 0.73, 6 h: 14.26 ± 1.24, 12 h: 37.47 ± 2.35, 24 h:264.80 ± 5.10(P < 0.05). The expression of sprE was 0 h: 7.72 ± 0.74, 6 h: 21.15 ± 0.96, 12 h:49.87 ± 3.18, 24 h:441.89 ± 7.74, which was significantly different among the 4 time period(P < 0.05).


CONCLUSIONS
The fsrB, gelE and sprE genes are closely related to the biofilm formation in Ef.
Department of Cariology and Endodontology, Yantai Stomatological Hospital Affiliated to Binzhou Medical College, Yantai Shandong 264008, China. Email: dentlzs@163.com.
Zhi-shan
ZS
Lu
Lei
L
Meng
Zhong-hao
ZH
Liu
Guang-hui
GH
Ren
Ai-jie
AJ
Sun
Xiang-mei
XM
Liu
D001426:Bacterial Proteins / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D013293:Enterococcus faecalis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018093:Gelatinases / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D053038:Quorum Sensing; D057057:Serine Proteases / Q000378:metabolism*
D001426:Bacterial Proteins; C409032:FsrB protein, Enterococcus; D057057:Serine Proteases; D018093:Gelatinases