title: [Effect of different stress conditions on growth and biofilm formation capability of Enterococcus faecalis].
abstract: OBJECTIVE
  To study the changes of growth and biofilm formation capability of Enterococcus faecalis (Ef) in different stress conditions.
  
  
  METHODS
  The changes of growth of Ef in stress conditions were observed by measuring the A600 value with ultraviolet spectrophotometer. Ef was incubated on glass slide in stress conditions, biofilm formation capability of cells was investigated by colony-forming unit (CFU) counting of the culturable bacteria and fluorescence confocal laser scanning microscopy.
  
  
  RESULTS
  Ef couldn't growth under the conditions of 2%, 5%NaClO, pH = 11 and 12, the A600 value was unchanged in 96 hours. But the growth curve changed at different levels in other stress conditions: under 1%NaClO, the A600 value peaked at 1.461 at 16 hour (the peaked level was 1.238 at 6 hours in control group) ; under 0,0.05%,0.15% glucose, it peaked at 0.645,0.890, 1.173, respectively, at 6 hour (it was maximized to 1.195 at 6 hours in control group); the A600 value peaked at 1.704 at 6 hours at pH = 9 and 1.225 at 10 hours at pH = 10 (the peak level was 1.732 at 6 hours at pH = 7) . Biofilm assay showed that Ef were able to form biofilm in these stress conditions except 5%NaClO and pH = 12.
  
  
  CONCLUSIONS
  Ef could growth and form biofilms in energy starvation, low concentrations of sodium hypochlorite and weak alkaline stress.
authors: Department of Endodontics, Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine & Shanghai Research Institute of Stomatology & Shanghai Key Laboratory of Stomatology, Shanghai 200011, China.
authors: Shu-jun
authors: SJ
authors: Ran
authors: Jia
authors: J
authors: E
authors: Cai-lian
authors: CL
authors: Zhu
authors: Zhi-yan
authors: ZY
authors: He
authors: Jing-ping
authors: JP
authors: Liang
mesh_terms: D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D015169:Colony Count, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects / Q000254:growth & development*; D005947:Glucose / Q000494:pharmacology*; D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal; D012973:Sodium Hypochlorite / Q000494:pharmacology*
chemical_list: D012973:Sodium Hypochlorite; D005947:Glucose