Involvement of NADH Oxidase in Competition and Endocarditis Virulence in Streptococcus sanguinis.
Infect Immun
; 84(5): 1470-1477, 2016 05.
Article
em En
| MEDLINE
| ID: mdl-26930704
ABSTRACT
Here, we report for the first time that the Streptococcus sanguinis nox gene encoding NADH oxidase is involved in both competition with Streptococcus mutans and virulence for infective endocarditis. An S. sanguinis nox mutant was found to fail to inhibit the growth of Streptococcus mutans under microaerobic conditions. In the presence of oxygen, the recombinant Nox protein of S. sanguinis could reduce oxygen to water and oxidize NADH to NAD(+) The oxidation of NADH to NAD(+) was diminished in the nox mutant. The nox mutant exhibited decreased levels of extracellular H2O2; however, the intracellular level of H2O2 in the mutant was increased. Furthermore, the virulence of the nox mutant was attenuated in a rabbit endocarditis model. The nox mutant also was shown to be more sensitive to blood killing, oxidative and acid stresses, and reduced growth in serum. Thus, NADH oxidase contributes to multiple phenotypes related to competitiveness in the oral cavity and systemic virulence.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Infecções Estreptocócicas
/
Streptococcus sanguis
/
Fatores de Virulência
/
Endocardite Bacteriana
/
Complexos Multienzimáticos
/
NADH NADPH Oxirredutases
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Infect Immun
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos