Biomaterial Database

Characterization of hydrogen peroxide-induced DNA release by Streptococcus sanguinis and Streptococcus gordonii. 2009

Jens Kreth, and Hung Vu, and Yongshu Zhang, and Mark C Herzberg

Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, Minnesota 55455, USA. JKreth@ouhsc.edu

Extracellular DNA (eDNA) is produced by several bacterial species and appears to contribute to biofilm development and cell-cell adhesion. We present data showing that the oral commensals Streptococcus sanguinis and Streptococcus gordonii release DNA in a process induced by pyruvate oxidase-dependent production of hydrogen peroxide (H(2)O(2)). Surprisingly, S. sanguinis and S. gordonii cell integrity appears unaffected by conditions that cause autolysis in other eDNA-producing bacteria. Exogenous H(2)O(2) causes release of DNA from S. sanguinis and S. gordonii but does not result in obvious lysis of cells. Under DNA-releasing conditions, cell walls appear functionally intact and ribosomes are retained over time. During DNA release, intracellular RNA and ATP are not coreleased. Hence, the release mechanism appears to be highly specific for DNA. Release of DNA without detectable autolysis is suggested to be an adaptation to the competitive oral biofilm environment, where autolysis could create open spaces for competitors to invade. Since eDNA promotes cell-to-cell adhesion, release appears to support oral biofilm formation and facilitates exchange of genetic material among competent strains.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D006861	Hydrogen Peroxide	A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.	Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D012329	RNA, Bacterial	Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.	Bacterial RNA
D013298	Streptococcus sanguis	A gram-positive organism found in dental plaque, in blood, on heart valves in subacute endocarditis, and infrequently in saliva and throat specimens. L-forms are associated with recurrent aphthous stomatitis.	Streptococcus sanguinis
D054773	Streptococcus gordonii	A species of gram-positive, facultatively anaerobic bacteria in the family STREPTOCOCCACEAE. It is a normal inhabitant of the human oral cavity, and causes DENTAL PLAQUE and ENDOCARDITIS. It is being investigated as a vehicle for vaccine delivery.