Biological changes of Enterococcus faecalis in the viable but nonculturable state.
Genet Mol Res
; 14(4): 14790-801, 2015 Nov 23.
Article
in En
| MEDLINE
| ID: mdl-26600540
Enterococcus faecalis may enter a viable but nonculturable (VBNC) state under adverse conditions. E. faecalis, the major bacterial species present in failed root canal treatments, is thought to survive after endodontic treatment by entering a VBNC state. In this study, we characterized the VBNC state of E. faecalis. We designed 3 different protocols to successfully induce the VBNC state. Approximately one-third of bacteria entered a VBNC state after 15-30 days, and all remained viable for at least 2 months. The morphology, glycometabolism, and adhesion capabilities of VBNC cells differed from those of E. faecalis during the exponential growth phase. Specifically, VBNC E. faecalis cells could not decompose lactose, D-mannitol, or D-sorbitol, although they were able to metabolize sucrose. Transmission electron microscopy showed that the morphology of the VBNC E. faecalis cells changed significantly; the cytoplasmic matrix was unevenly condensed and the overall morphology of the cells became irregular, but the cell membranes remained intact. Although the adhesion ability of the bacteria decreased, VBNC E. faecalis could still adhere to collagen fiber type I and tooth dentine. The persistence of this adhesion ability may be important in the virulence of VBNC E. faecalis.
Full text:
1
Database:
MEDLINE
Main subject:
Bacterial Adhesion
/
Enterococcus faecalis
/
Dental Pulp Cavity
Type of study:
Guideline
Limits:
Humans
Language:
En
Journal:
Genet Mol Res
Journal subject:
BIOLOGIA MOLECULAR
/
GENETICA
Year:
2015
Type:
Article
Affiliation country:
China