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Reactive oxygen species bacteria

Sreegowrinadh Javvadi, Sheo Shankar Pandey, Amita Mishra, Binod Bihari Pradhan, Subhadeep Chatterjee
Cellular iron homeostasis is critical for survival and growth. Bacteria employ a variety of strategies to sequester iron from the environment and to store intracellular iron surplus that can be utilized in iron-restricted conditions while also limiting the potential for the production of iron-induced reactive oxygen species (ROS). Here, we report that membrane-derived oligosaccharide (mdo) glucan, an intrinsic component of Gram-negative bacteria, sequesters the ferrous form of iron. Iron-binding, uptake, and localization experiments indicated that both secreted and periplasmic β-(1,2)-glucans bind iron specifically and promote growth under iron-restricted conditions...
December 8, 2017: EMBO Reports
Manoj-Kumar Arthikala, Jesús Montiel, Rosana Sánchez-López, Noreide Nava, Luis Cárdenas, Carmen Quinto
Reactive oxygen species (ROS) produced by respiratory burst oxidase homologs (RBOHs) regulate numerous plant cell processes, including the symbiosis between legumes and nitrogen-fixing bacteria. Rapid and transient ROS production was reported after Phaseolus vulgaris root hairs were treated with Nod factors, indicating the presence of a ROS-associated molecular signature in the symbiosis signaling pathway. Rboh is a multigene family containing nine members (RbohA-I) in P. vulgaris. RNA interference of RbohB suppresses ROS production and attenuates rhizobial infection thread (IT) progression in P...
2017: Frontiers in Plant Science
C Matziouridou, S D C Rocha, O A Haabeth, K Rudi, H Carlsen, A Kielland
The intestinal epithelial cells constitute the first line of defense against gut microbes, which includes secretion of various antimicrobial substances. Reactive oxygen species (ROS) are well characterized as part of the innate phagocytic immunity; however, a role in controlling microorganisms in the gut lumen is less clear. Here, we show a role for nitric oxide synthase (iNOS)- and NOX1-produced ROS in maintaining homeostasis of the gut microbiota. In vivo imaging revealed distinctly high levels of ROS in the ileum of normal healthy mice, regulated in accordance with the amount of gut bacteria...
December 6, 2017: Mucosal Immunology
Chao-Jung Wu, Tsu-Ting Chiu, Yi-Tsung Lin, Yi-Wei Huang, Li-Hua Li, Tsuey-Ching Yang
Overexpression of resistance-nodulation-division (RND)-type efflux pumps is an important mechanism for bacteria to combat antimicrobials. RND efflux pumps are also critical for bacterial physiology such as oxidative stress tolerance. Stenotrophomonas maltophilia, a multi-drug resistant opportunistic pathogen, harbors eight RND-type efflux pump operons. Of them, smeU1VWU2X operon is unique for its possession of two additional genes, smeU1 and smeU2, which encode proteins of short-chain dehydrogenase/reductase (SDR) family...
December 4, 2017: Antimicrobial Agents and Chemotherapy
Maria Fernanda Taviano, Antonietta Melchini, Angela Filocamo, Chiara Costa, Stefania Catania, Roberto Raciti, Shikha Saha, Paul Needs, Giuseppe Giovanni Bisignano, Natalizia Miceli
Background: Eruca sativa Mill. (Brassicaceae) is commonly utilized as an ingredient in salads and also as a folk remedy to treat various diseases. Objective: The objective of this study was to establish the contribution of the glucosinolate (GLS) fraction to the overall antioxidant, cytoprotection against oxidative insult and antimicrobial properties of the hydro-alcoholic extract of E. sativa leaves from Sicily (Italy), characterized phytochemically. Materials and Methods: The antioxidant activity was evaluated by different in vitro systems...
October 2017: Pharmacognosy Magazine
Pinar Erkekoglu, Didem Oral, Belmar Kocer-Gumusel, Ming-Wei Chao
The association between inflammation and cancer has long been recognized. Several studies have found that different types of tumors develop at sites of chronic inflammation. It is stated that over 15%-20% of malignancies worldwide can be related to infections caused by viruses, bacteria, and schistosomes. Inflammatory conditions are characterized by overexpression of inducible nitric oxide synthase (iNOS) and overproduction of nitric oxide/reactive nitrogen species (ROSs/RNSs) in epithelial cells. Reactive oxygen species (ROSs) may also lead to cellular alterations and eventually to inflammation...
2017: Journal of Environmental Pathology, Toxicology and Oncology
Danuta Kaczmarzyk, Ivana Cengic, Lun Yao, Elton P Hudson
Fatty alcohol production in Synechocystis sp. PCC 6803 was achieved through heterologous expression of the fatty acyl-CoA/ACP reductase Maqu2220 from the bacteria Marinobacter aquaeolei VT8 and the fatty acyl-ACP reductase DPW from the rice Oryza sativa. These platform strains became models for testing multiplex CRISPR-interference (CRISPRi) metabolic engineering strategies to both improve fatty alcohol production and to study membrane homeostasis. CRISPRi allowed partial repression of up to six genes simultaneously, each encoding enzymes of acyl-ACP-consuming pathways...
November 30, 2017: Metabolic Engineering
Aafreen Fathima, Jonnalagadda Raghava Rao
The objective of this work is to detect the mode of damage caused by Cr(III), one of the widely used industrial pollutant on Bacillus subtilis-industrial strain 168 and Escherichia coli MTCC 40. Bioassays are very sensitive, precise, economical and rapid for detecting early stages of pollution. The detrimental effect of trivalent chromium becomes clear from the growth profile and growth inhibition studies. Mode of action of damage by trivalent chromium in bacterial model was found to be oxidative, as chromium is one of the redox active metals...
November 30, 2017: Archives of Microbiology
Edwin T Gnanaprakasam, Jonathan R Lloyd, Christopher Boothman, Kazi Matin Ahmed, Imtiaz Choudhury, Benjamin C Bostick, Alexander van Geen, Brian J Mailloux
Long-term exposure to trace levels of arsenic (As) in shallow groundwater used for drinking and irrigation puts millions of people at risk of chronic disease. Although microbial processes are implicated in mobilizing arsenic from aquifer sediments into groundwater, the precise mechanism remains ambiguous. The goal of this work was to target, for the first time, a comprehensive suite of state-of-the-art molecular techniques in order to better constrain the relationship between indigenous microbial communities and the iron and arsenic mineral phases present in sediments at two well-characterized arsenic-impacted aquifers in Bangladesh...
November 28, 2017: MBio
Emma Louise Walton
In this issue of the Biomedical Journal, we discuss the emerging role of reactive oxygen species (ROS) in the development of insulin resistance and ultimately type 2 diabetes. We focus also on research investigating the outcome of in vitro fertilization after laproscopic surgery for ovarian endometriosis. Finally, we learn the results of a study on the hunt for new probiotic bacteria.
October 2017: Biomedical Journal
William Wang, Jiayuan Hou, Zhenghua Zhu, Hao Fang
Mitochondrial dysfunction has historically been linked to the cessation of cell function and ageing. Downstream effects such as reduced calcium buffering capacity, elevated levels of reactive oxygen species, and alterations in adenosine-5'-triphosphate are linked to a wide variety of pathological diseases. The importance of the mitochondria has increasingly been highlighted due to its potential as a therapeutic target for drug intervention and cell elimination in cancer. In addition, due to its origin, drugs targeting bacteria are required to be thoroughly tested prior to administration to prevent toxicity for the mitochondria...
2017: Advances in Experimental Medicine and Biology
Suresh K Verma, Ealisha Jha, Pritam Kumar Panda, Jugal K Das, Arun Thirumurugan, Mrutyunjay Suar, Sks Parashar
AIM: To investigate molecular aspects of the antibacterial effect of size-dependent core-shell intrinsic defects of nanocrystalline ZnO synthesized through high energy ball milling technique. MATERIALS & METHODS: Mechanically synthesized and characterized 7, 10 and 15 h milled ZnO nanoparticles were evaluated for antibacterial activity with molecular investigation by computational molecular docking. RESULTS: Synthesized ZnO nanoparticles displayed shrinkage of core and increase of shell with reduction in size of bulk ZnO particles from 250 to 80, 40 and 20 nm and increase in zeta potential up to -19 mV in 7, 10 and 15 h nano ZnO...
November 27, 2017: Nanomedicine
Liyi Huang, Ahmed El-Hussein, Weijun Xuan, Michael R Hamblin
We recently reported that addition of the non-toxic salt, potassium iodide can potentiate antimicrobial photodynamic inactivation of a broad-spectrum of microorganisms, producing many extra logs of killing. If the photosensitizer (PS) can bind to the microbial cells, then delivering light in the presence of KI produces short-lived reactive iodine species, while if the cells are added after light the killing is caused by molecular iodine produced as a result of singlet oxygen-mediated oxidation of iodide. In an attempt to show the importance of PS-bacterial binding, we compared two charged porphyrins, TPPS4 (thought to be anionic and not able to bind to Gram-negative bacteria) and TMPyP4 (considered cationic and well able to bind to bacteria)...
October 31, 2017: Journal of Photochemistry and Photobiology. B, Biology
Han-Bo Liu, Wei-Wei Gao, Vijai Kumar Reddy Tangadanchu, Cheng-He Zhou, Rong-Xia Geng
A series of novel aminopyrimidinyl benzimidazoles as potentially antimicrobial agents were designed, synthesized and characterized by IR, NMR and HRMS spectra. The biological evaluation in vitro revealed that some of the target compounds exerted good antibacterial and antifungal activity in comparison with the reference drugs. Noticeably, compound 7d could effectively inhibit the growth of A. flavus, E. coli DH52 and MRSA with MIC values of 1, 1 and 8 μg/mL, respectively. Further studies revealed that pyrimidine derivative 7d could exhibit bactericidal mode of action against both Gram positive (S...
November 10, 2017: European Journal of Medicinal Chemistry
Rogério Rodrigo Ramos, Jeferson Leandro de Paiva, José Paulo Franco Dos Santos Gomes, Nagib Pezati Boer, José Maria Pereira de Godoy, Fernando Batigalia
BACKGROUND: Photodynamic therapy is a therapeutic modality that has consolidated its activity in the photooxidation of organic matter, which arises from the activity of reactive oxygen species. OBJECTIVE: To evaluate the effect of red laser 660nm with the photosensitizer methylene blue on Propionibacterium acnes in vitro. METHOD: The experimental design was distributed into four groups (1 - control group without the application of light and without photosensitizer, 2 - application of light, 3 - methylene blue without light, and 4 - methylene blue with light)...
September 2017: Anais Brasileiros de Dermatologia
Omid Teymournejad, Mingqun Lin, Yasuko Rikihisa
The obligatory intracellular pathogen Ehrlichia chaffeensis lacks most genes that confer resistance to oxidative stress but can block reactive oxygen species (ROS) generation by host monocytes-macrophages. Bacterial and host molecules responsible for this inhibition have not been identified. To infect host cells, Ehrlichia uses the C terminus of its surface invasin, entry-triggering protein of Ehrlichia (EtpE; EtpE-C), which directly binds the mammalian cell surface receptor glycosylphosphatidylinositol-anchored protein DNase X...
November 21, 2017: MBio
Ah-Mee Park, Seiichi Omura, Mitsugu Fujita, Fumitaka Sato, Ikuo Tsunoda
Alteration of microbiota has been associated with intestinal, inflammatory, and neurological diseases. Abundance of "good bacteria" such as Bifidobacterium, or their products have been generally believed to be beneficial for any diseases, while "bad bacteria" such as pathogenic Helicobacter pylori are assumed to be always detrimental for hosts. However, this is not the case when we compare and contrast the association of the gut microbiota with two neurological diseases, multiple sclerosis (MS) and Alzheimer's disease (AD)...
August 2017: Clinical & Experimental Neuroimmunology
E T Carrera, H B Dias, S C T Corbi, R A C Marcantonio, A C A Bernardi, V S Bagnato, M R Hamblin, A N S Rastelli
In recent years there have been an increasing number of in vitro and in vivo studies that show positive results regarding antimicrobial photodynamic therapy (aPDT) used in dentistry. These include applications in periodontics, endodontics, and mucosal infections caused by bacteria present as biofilms. Antimicrobial photodynamic therapy is a therapy based on the combination of a non-toxic photosensitizer (PS) and appropriate wavelength visible light, which in the presence of oxygen is activated to produce reactive oxygen species (ROS)...
December 2016: Laser Physics
Xiaomei Dai, Xuelei Chen, Yu Zhao, Yunjian Yu, Xiaosong Wei, Xinge Zhang, Chaoxing Li
A multitude of serious chronic infections involved in bacterial biofilms that are difficult to eradicate. Here, a water-soluble galactose functionalized cationic 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based photodynamic therapy agent was synthesized for selectively eliminating the bacterial biofilm. These conjugates can capture bacteria to form aggregations through electrostatic interaction and then generate a large number of reactive oxygen species (ROS) under visible light irradiation to kill the bacteria without the emergence of bacterial resistance...
November 15, 2017: Biomacromolecules
Maria E Lopes Pires, Simon R Clarke, Sisi Marcondes, Jonathan M Gibbins
Lipopolysaccharide (LPS) from the cell envelope of Gram-negative bacteria is a principal cause of the symptoms of sepsis. LPS has been reported to modulate the function of platelets although the underlying mechanisms of LPS action in these cells remain unclear. Platelets express the Toll-like receptor 4 (TLR4) which serves as a receptor for LPS, although the potential role of TLR4 and associated cell signalling in controlling platelet responses to LPS has not been extensively explored. In this study, we therefore investigated the actions of LPS prepared from different strains of Escherichia coli on platelet function, the underlying signalling mechanisms, and the potential role of TLR4 in orchestrating these...
2017: PloS One
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