Related Experiment Videos
Differential modulation of adherence of oral streptococci by human neutrophil myeloperoxidase
K T Miyasaki1, P M de Camargo, L E Wolinsky
1Section of Periodontics, School of Denistry, University of California, Los Angeles 90024.
Abstract:
In this study, the modulation of adherence of hydrogen peroxide (H2O2)-producing and non-H2O2-producing strains of oral streptococci by the host leukocyte enzyme myeloperoxidase (MPO) was examined. It was found that exposure to MPO decreased adherence of many strains of oral streptococci to saliva-coated hydroxyapatite beads in the presence of exogenous H2O2 and chloride. The MPO-H2O2-Cl-system increased the adherence of one strain. In the absence of exogenous H2O2, the MPO-H2O2-Cl-system decreased the adherence of H2O2-producing strains only. Glucose increased streptococcal H2O2 production and also increased the anti-adhesive activity of MPO in the absence of exogenous H2O2. We conclude that: (1) host leukocytes can modulate the adherence of oral streptococci via MPO; (2) endogenous production of H2O2 by the oral streptococci can provide sufficient substrate H2O2 to drive this system; and (3) MPO will exert differential modulatory effects on the adherence of oral streptococci, based in part upon the level of endogenous H2O2 production and in part upon the particular characteristics of the adhesins of the bacteria.
Insights
The host enzyme myeloperoxidase (MPO) can alter oral streptococci adherence to teeth. MPO
Area of Science:
- Oral microbiology
- Host-pathogen interactions
- Enzyme function
Background:
- Oral streptococci are key players in dental plaque formation.
- Myeloperoxidase (MPO) is an enzyme released by host leukocytes.
- The interaction between MPO and oral bacteria influences the oral environment.
Purpose of the Study:
- To investigate how myeloperoxidase (MPO) affects the adherence of oral streptococci.
- To determine the role of hydrogen peroxide (H2O2) in MPO-mediated bacterial adherence.
- To explore the impact of bacterial H2O2 production on MPO's activity.
Main Methods:
- Assessing bacterial adherence to saliva-coated hydroxyapatite beads.
- Utilizing H2O2-producing and non-H2O2-producing strains of oral streptococci.
- Exposing bacteria to MPO, H2O2, and chloride, with and without glucose.
Main Results:
- MPO generally decreased streptococcal adherence in the presence of H2O2 and chloride.
- MPO-H2O2-Cl system enhanced adherence in one specific strain.
- In the absence of exogenous H2O2, MPO primarily reduced adherence of H2O2-producing strains.
- Glucose increased bacterial H2O2 production and MPO's anti-adhesive effect.
Conclusions:
- Host leukocytes, via MPO, can modulate oral streptococci adherence.
- Endogenous H2O2 production by streptococci is sufficient to activate MPO's effects.
- MPO's influence on bacterial adherence is strain-specific, depending on H2O2 production and bacterial adhesins.