scholarly journals Role of prokaryotic Cu,Zn superoxide dismutase in pathogenesis

2003 ◽  
Vol 31 (6) ◽  
pp. 1326-1329 ◽  
Author(s):  
A. Battistoni
Keyword(s):  
Superoxide Dismutase ◽  
Bacterial Pathogens ◽  
Superoxide Dismutases ◽  
Bacterial Survival ◽  
Bacterial Killing ◽  
Multiple Copies ◽  
Micro Organisms ◽  
Radical Damage ◽  
Type Strains

Several bacterial pathogens possess sodC genes that encode periplasmic or membrane-associated Cu,Zn superoxide dismutases. Since professional phagocytes generate large amounts of reactive oxygen species to control the growth of invading micro-organisms, Cu,Zn superoxide dismutase might protect infectious bacteria from oxy-radical damage and facilitate their survival within the host. This idea has gained support from studies showing that sodC-null mutants of different bacteria are less virulent than their parental wild-type strains, and from the discovery that, despite apparent dispensability for growth under laboratory conditions, various pathogens (including several highly virulent Salmonella strains) possess multiple copies of sodC. Our studies indicate that Cu,Zn superoxide dismutase effectively protects bacteria from phagocytic killing, and that the role in infection of the redundant sodC genes may vary in distinct Salmonella enterica serovars. More unexpectedly, we have found that Cu,Zn superoxide dismutase also modulates bacterial survival within epithelial cells, where bacterial killing appears to be mediated by an NAD(P)H oxidase resembling the enzyme complex typical of phagocytes. Finally, a striking feature of Cu,Zn superoxide dismutases from bacterial pathogens is their apparent ability to exploit the structural versatility of the enzyme to modulate its function. In fact, several enzyme variants exhibit unique properties that may lead to the acquisition of novel specialized functions distinct from superoxide dismutation.

scholarly journals Role of superoxide dismutase in survival of Leishmania within the macrophage

2003 ◽  
Vol 369 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Sanjay GHOSH ◽  
Srikanta GOSWAMI ◽  
Samit ADHYA
Keyword(s):  
Superoxide Dismutase ◽  
Antisense Rna ◽  
Axenic Culture ◽  
Free Radical Damage ◽  
Enhanced Sensitivity ◽  
Mouse Macrophages ◽  
Parasite Survival ◽  
Radical Damage ◽  
Genus Leishmania

Intracellular parasitic protozoans of the genus Leishmania depend for their survival on the elaboration of enzymic and other mechanisms for evading toxic free-radical damage inflicted by their phagocytic macrophage host. One such mechanism may involve superoxide dismutase (SOD), which detoxifies reactive superoxide radicals produced by activated macrophages, but the role of this enzyme in parasite survival has not yet been demonstrated. We have cloned a SOD gene from L. tropica and generated SOD-deficient parasites by expressing the corresponding antisense RNA from an episomal vector. Such parasites have enhanced sensitivity to menadione and hydrogen peroxide in axenic culture, and a markedly reduced survival in mouse macrophages. These results indicate that SOD is a major determinant of intracellular survival of Leishmania.

Oxygen-induced changes in pulmonary superoxide dismutase assayed by antibody titrations

1976 ◽  
Vol 231 (4) ◽  
pp. 1196-1203 ◽  
Author(s):  
JD Crapo ◽  
JM McCord
Keyword(s):  
Superoxide Dismutase ◽  
Rat Liver ◽  
Significant Role ◽  
Superoxide Dismutases ◽  
Absolute Amount ◽  
Sod Activity ◽  
Oxygen Tolerance ◽  
Induced Changes ◽  
Development Of Tolerance

Previous studies have demonstrated a 50% increase in pulmonary superoxide dismutase (SOD) activity in oxygen-adapted rats and have suggested that SOD plays a significant role in the development of "tolerance". To further study these events, the cuprozinc SOD was purified from rat liver and found to be similar to previously purified cuprozinc superoxide dismutases. A rabbit antisera to rat cuprozinc SOD was produced and used to perform antibody titrations of SOD in the lungs of rats exposed to 85% O2 for 5 days. The absolute amount of cuprozinc SOD increased 41% by antibody titration which accounted for most, if not all, of the 48% increase demonstrated in total SOD activity. Spectrophotometric assays at pH 7.8 and 10.0 of pure rat cuprozinc SOD and crude lung homogenates suggest that there is also a manganese SOD present, but the role of that SOD in the development of oxygen tolerance has not been established.

scholarly journals Mycobacterial catalases, peroxidases, and superoxide dismutases and their effects on virulence and isoniazid-susceptibility in mycobacteria – a review

2012 ◽  
Vol 49 (No. 5) ◽  
pp. 161-170 ◽  
Author(s):  
M. Bartos ◽  
J. O Falkinham ◽  
III ◽  
I. Pavlik
Keyword(s):  
Superoxide Dismutase ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Superoxide Dismutases ◽  
Number Of Factors ◽  
Catalase Peroxidase ◽  
Genus Mycobacterium ◽  
Survival And Growth ◽  
Characteristic Features

Mycobacteria are intracellular bacterial parasites which survive and proliferate inside of macrophages for long periods of time. Because mycobacterial survival in macrophages is required for virulence, a great deal of effort has been focused on identifying the genetic and physiologic determinants of intracellular survival and growth. A number of factors, among them catalases, peroxidases, and superoxide dismutase have been suggested as agents permitting mycobacteria to overcome the intracellular defences of macrophages. The characteristic features of mycobacterial catalase/peroxidases and superoxide dismutase, their distribution within the genus Mycobacterium, and their mutual interactions in the inactivation of toxic oxygen products are reviewed. Focus is placed on evidence of the role of mycobacterial catalase-peroxidase and superoxide dismutase in virulence and on the role of catalase-peroxidase in susceptibility to isonicotinic acid hydrazide.

The role of intracanal medicaments in inhibition of bacteria isolated from root canals of infected primary molars

2019 ◽  
Vol 14 (1) ◽  
pp. 92
Author(s):  
Dr. Maha Abdul- Kareem Mahmood ◽  
Dr. Huda Elias Ali ◽  
Dr. Haraa Khairi Abdul-Kadher
Keyword(s):  
Antimicrobial Activity ◽  
Streptococcus Mutans ◽  
Normal Saline ◽  
Root Canal ◽  
Primary Teeth ◽  
Primary Molars ◽  
Root Canals ◽  
Etiologic Agents ◽  
Micro Organisms

Microbes are considered as the primary etiologic agents in endodontic diseases.Disinfection of the root canal is obtained by the combined effect of biomechanicalpreparation, irrigation and intra canal medicament. The aim of the present study wasto assess the antimicrobial activity of intracanal medicaments (formocresol andEndosepton) against two micro organisms (Streptococcus mutans and staphylococcusaureus) isolated from 15 necrotic pulps of primary molars indicated for pulpectomyprocedure. The samples were cultured, and purified using microbiological evaluation.Broth dilution test was performed in our study by preparing test tubes containing10 ml of BHI broth (pH. 7) which then inoculated with strains of the tested bacteriaand incubated at 37 C° for 24 h. After over night incubaction, ten fold dilution weremade in test tubes containing 9 ml of normal saline by adding 1 ml of the inoculum tothe first tube . Then from dilution 10-1 , 0.1 ml of cell suspension was added to 9.9 mlof formocresol and endosepton, then 0.1 ml was taken and spread on duplicates ofBHI agar plates at different intervals and incubated aerobically for 24 h. at 37 C°.Colonies on the plates were counted after incubation and CFU/mL (colony formingunit) was calculated. Our results indicating that there were no significant differencesbetween the intracanal medicaments, but there were high significant differencesbetween the intervals time of the study. We concluded that both materials had greatantibacterial effect against the pathogens commonly isolated from necrotic pulpaltissue of primary teeth.

Study of antioxidant potential in leaves, stems, nuts of Juglans regia L.

2012 ◽  
Vol 1 (10) ◽  
pp. 79 ◽  
Author(s):  
G. Raja* ◽  
Ivvala Anand Shaker ◽  
Inampudi Sailaja ◽  
R. Swaminathan ◽  
S. Saleem Basha ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Juglans Regia ◽  
Radical Scavenging ◽  
Antioxidant Compounds ◽  
Free Radical Damage ◽  
Radical Damage

Natural antioxidants can protect the human body from free radicals and retard the progress of many chronic diseases as well as lipid oxidative rancidity in foods. The role of antioxidants has protected effect against free radical damage that may cause many diseases including cancer. Primary sources of naturally occurring antioxidants are known as whole grains, fruits, and vegetables. Several studies suggest that regular consumption of nuts, mostly walnuts, may have beneficial effects against oxidative stress mediated diseases such as cardiovascular disease and cancer. The role of antioxidants has attracted much interest with respect to their protective effect against free radical damage that may cause many diseases including cancer. Juglans regia L. (walnut) contains antioxidant compounds, which are thought to contribute to their biological properties. Polyphenols, flavonoids and flavonols concentrations and antioxidant activity of Leaves, Stems and Nuts extract of Juglans regia L. as evaluated using DPPH, ABTS, Nitric acid, hydroxyl and superoxide radical scavenging activity, lipid peroxidation and total oxidation activity were determined. The antioxidant activities of Leaves, Stems and Nuts extract of Juglans regia L. were concentration dependent in different experimental models and it was observed that free radicals were scavenged by the test compounds in all the models.

scholarly journals ROS Defense Systems and Terminal Oxidases in Bacteria

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 839
Author(s):  
Vitaliy B. Borisov ◽  
Sergey A. Siletsky ◽  
Martina R. Nastasi ◽  
Elena Forte
Keyword(s):  
Defense Mechanisms ◽  
Protective Role ◽  
Superoxide Dismutases ◽  
Oxygen Species ◽  
Ros Scavenging ◽  
Terminal Oxidases ◽  
Defense Systems ◽  
Respiratory Chains ◽  
Scavenging Enzymes

Reactive oxygen species (ROS) comprise the superoxide anion (O2·−), hydrogen peroxide (H2O2), hydroxyl radical (·OH), and singlet oxygen (1O2). ROS can damage a variety of macromolecules, including DNA, RNA, proteins, and lipids, and compromise cell viability. To prevent or reduce ROS-induced oxidative stress, bacteria utilize different ROS defense mechanisms, of which ROS scavenging enzymes, such as superoxide dismutases, catalases, and peroxidases, are the best characterized. Recently, evidence has been accumulating that some of the terminal oxidases in bacterial respiratory chains may also play a protective role against ROS. The present review covers this role of terminal oxidases in light of recent findings.

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