Bacterial lysine decarboxylase influences human dental biofilm lysine content, biofilm accumulation, and subclinical gingival inflammation

Zsolt Lohinai, Beata Keremi, Eva Szoko, Tamas Tabi, Csaba Szabo, Zsolt Tulassay, Martin Levine

Research output: Contribution to journalArticlepeer-review

19 Scopus citations


Background: Dental biofilms contain a protein that inhibits mammalian cell growth, possibly lysine decarboxylase from Eikenella corrodens. This enzyme decarboxylates lysine, an essential amino acid for dentally attached cell turnover in gingival sulci.Lysinedepletionmay stopthis turnover, impairingthebarrier to bacterial compounds. The aims of this study are to determine biofilm lysine and cadaverine contents before oral hygiene restriction (OHR) and their association with plaque index (PI) and gingival crevicular fluid (GCF) after OHR for 1 week. Methods: Laser-induced fluorescence after capillary electrophoresis was used to determine lysine and cadaverine contents in dental biofilm, tongue biofilm, and saliva before OHR and in dental biofilm after OHR. Results: BeforeOHR, lysine and cadaverine contents of dental biofilm were similar and 10-fold greater than in saliva or tongue biofilm. After 1 week of OHR, the biofilm content of cadaverine increased and that of lysine decreased, consistent with greater biofilm lysine decarboxylase activity. Regression indicated that PI and GCF exudation were positively related to biofilm lysine after OHR, unless biofilm lysine exceeded the minimal blood plasma content, in which case PI was further increased but GCF exudation was reduced. Conclusions: After OHR, lysine decarboxylase activity seems to determine biofilm lysine content and biofilm accumulation. When biofilm lysine exceedsminimal blood plasma content after OHR, less GCF appeared despite more biofilm. Lysine appears important for biofilm accumulation and the epithelial barrier to bacterial proinflammatory agents. Inhibiting lysine decarboxylase may retard the increased GCF exudation required for microbial development and gingivitis.

Original languageEnglish (US)
Pages (from-to)1048-1056
Number of pages9
JournalJournal of Periodontology
Issue number8
StatePublished - Aug 2012
Externally publishedYes


  • Gingival crevicular fluid
  • Gingivitis
  • Microbiology
  • Oral hygiene
  • Periodontal disease

ASJC Scopus subject areas

  • Periodontics


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