کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
3415362 1224956 2008 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The two-component system ScnRK of Streptococcus mutans affects hydrogen peroxide resistance and murine macrophage killing
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ایمونولوژی
پیش نمایش صفحه اول مقاله
The two-component system ScnRK of Streptococcus mutans affects hydrogen peroxide resistance and murine macrophage killing
چکیده انگلیسی

To survive macrophage killing is critical in the pathogenesis of viridians streptococci-induced infective endocarditis (IE). Streptococcus mutans, an opportunistic IE pathogen, generally does not survive well phagocytic killing in murine macrophage RAW 264.7 cells. A putative two-component system (TCS), ScnR/ScnK from S. mutans, was investigated to elucidate the mechanisms underlying bacteria-cellular interaction in this study. Both the wild-type and mutant strains were phagocytosed by RAW 264.7 cells at a comparable rate and an increased intracellular susceptibility during a 5 h incubation period was observed with the scnRK-null mutants. The amount of reactive oxygen species (ROS) in activated macrophages was reduced significantly after ingesting wild-type, but not scnRK-null mutant strains, suggesting that increased macrophage killing of these mutants is due to the impaired ability of S. mutans to counteract ROS. Additionally, both scnR- or scnRK-null mutants were more susceptible to hydrogen peroxide. Interestingly, scnRK expression was unaffected by hydrogen peroxide. These experimental results indicate that scnRK is important in counteracting oxidative stress in S. mutans, and decreased susceptibility to phagocytic killing is at least partly attributable to inhibition of intracellular ROS formation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microbes and Infection - Volume 10, Issue 3, March 2008, Pages 293–301
نویسندگان
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