D Das1, S S Saha, B Bishayi. 1. Department of Physiology, Immunology Laboratory, University of Calcutta, 92, APC Road, Kolkata, 700009, West Bengal, India.
Abstract
BACKGROUND: Superoxide dismutase (SOD) and catalase are anti-oxidant enzymes potentially used by the bacteria to neutralize macrophage microbicidal molecules such as hydrogen peroxide (H2O2). OBJECTIVE: To investigate contribution of bacterial anti-oxidant enzymes in intracellular survival of Staphylococcus aureus (S. aureus) within macrophages. MATERIALS: Murine peritoneal macrophages and S. aureus (CMC-524, ICH-629 and ICH-757). TREATMENT: 10(6) colony forming units (CFU) of the 90 minutes (min) intracellularly viable S. aureus were administered (i.v.) per mouse through 0.1 ml saline. METHODS: Anti-oxidant enzyme assay, phagocytic activity, H2O2 release, Zymography for catalase, serum tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) level were estimated. One-way Model I ANOVA and one tail Student's t-test were performed. RESULTS: Survival of S. aureus was least after 90 min of reincubation within macrophages. Maximum amount of bacterial anti-oxidant enzymes were released after 90 min of re-incubation. H2O2 released after 90 min of re-incubation with S. aureus was maximum. Higher activity of catalase and SOD by S. aureus occurred in response to the gradual production of H2O2. Serum IL-6 and TNF-alpha was also elevated 1h post infection. CONCLUSIONS: Bacterial catalase and SOD combat reactive oxygen species enabling S. aureus to persist within macrophages, inducing local inflammation, causing greater induction of serum TNF-alpha and IL-6.
BACKGROUND: Superoxide dismutase (SOD) and catalase are anti-oxidant enzymes potentially used by the bacteria to neutralize macrophage microbicidal molecules such as hydrogen peroxide (H2O2). OBJECTIVE: To investigate contribution of bacterial anti-oxidant enzymes in intracellular survival of Staphylococcus aureus (S. aureus) within macrophages. MATERIALS: Murine peritoneal macrophages and S. aureus (CMC-524, ICH-629 and ICH-757). TREATMENT: 10(6) colony forming units (CFU) of the 90 minutes (min) intracellularly viable S. aureus were administered (i.v.) per mouse through 0.1 ml saline. METHODS: Anti-oxidant enzyme assay, phagocytic activity, H2O2 release, Zymography for catalase, serum tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) level were estimated. One-way Model I ANOVA and one tail Student's t-test were performed. RESULTS: Survival of S. aureus was least after 90 min of reincubation within macrophages. Maximum amount of bacterial anti-oxidant enzymes were released after 90 min of re-incubation. H2O2 released after 90 min of re-incubation with S. aureus was maximum. Higher activity of catalase and SOD by S. aureus occurred in response to the gradual production of H2O2. Serum IL-6 and TNF-alpha was also elevated 1h post infection. CONCLUSIONS: Bacterial catalase and SOD combat reactive oxygen species enabling S. aureus to persist within macrophages, inducing local inflammation, causing greater induction of serum TNF-alpha and IL-6.
Authors: Michael W Ellis; Ryan C Johnson; Katrina Crawford; Jeffrey B Lanier; D Scott Merrell Journal: J Clin Microbiol Date: 2013-10-16 Impact factor: 5.948
Authors: Vijaya Kumar Yajjala; Vinai Chittezham Thomas; Christopher Bauer; Tyler D Scherr; Karl J Fischer; Paul D Fey; Kenneth W Bayles; Tammy Kielian; Keer Sun Journal: J Immunol Date: 2016-04-06 Impact factor: 5.422