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Reactive oxygen species bacteria

Khwaja Salahuddin Siddiqi, Azamal Husen, Rifaqat A K Rao
Use of silver and silver salts is as old as human civilization but the fabrication of silver nanoparticles (Ag NPs) has only recently been recognized. They have been specifically used in agriculture and medicine as antibacterial, antifungal and antioxidants. It has been demonstrated that Ag NPs arrest the growth and multiplication of many bacteria such as Bacillus cereus, Staphylococcus aureus, Citrobacter koseri, Salmonella typhii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Vibrio parahaemolyticus and fungus Candida albicans by binding Ag/Ag + with the biomolecules present in the microbial cells...
February 16, 2018: Journal of Nanobiotechnology
M Peana, C T Chasapis, G Simula, S Medici, M A Zoroddu
A complex network of regulatory proteins takes part in the mechanism underlying the radioresistance of Deinoccocus radiodurans bacterium (DR). The interaction of Mn(II) ions with DR-proteins and peptides seems to be responsible for proteins protection from oxidative damage induced by Reactive Oxygen Species during irradiation. In the present work we describe a combined approach of bioinformatic strategies based on structural data and annotation to predict the Mn(II)-binding proteins encoded by the genome of DR and, in parallel, the same predictions for other bacteria were performed; the comparison revealed that, in most of the cases, the content of Mn(II)-binding proteins is significantly higher in radioresistant than in radiosensitive bacteria...
February 7, 2018: Journal of Trace Elements in Medicine and Biology
Rilee Zeinert, Eli Martinez, Jennifer Schmitz, Katherine Senn, Bakhtawar Usman, Vivek Anantharaman, L Aravind, Lauren S Waters
Manganese is an essential trace nutrient for organisms, because of its role in cofactoring enzymes and providing protection against reactive oxygen species (ROS). Many bacteria require manganese to form pathogenic or symbiotic interactions with eukaryotic host cells. However, excess manganese is toxic, requiring cells to have manganese export mechanisms. Bacteria are currently known to possess two widely-distributed classes of manganese export proteins, MntP and MntE, but other types of transporters likely exist...
February 13, 2018: Journal of Biological Chemistry
Tamiko Nagao, Haruyuki Nakayama-Imaohji, Miad Elahi, Ayano Tada, Emika Toyonaga, Hisashi Yamasaki, Katsuichiro Okazaki, Hirokazu Miyoshi, Koichiro Tsuchiya, Tomomi Kuwahara
Excessive damage to DNA and lipid membranes by reactive oxygen species reduces the viability of bacteria. In the present study, the proliferation of recA‑deficient Escherichia coli strains was revealed to be inhibited by 1% L‑histidine under aerobic conditions. This inhibition of proliferation was not observed under anaerobic conditions, indicating that L‑histidine enhances oxidative DNA damage to E. coli cells. Reverse transcription‑quantitative polymerase chain reaction analysis demonstrated that the expression of recA in E...
February 7, 2018: International Journal of Molecular Medicine
Lizziane de Francisco, Diana Pinto, Hélen Rosseto, Lucas Toledo, Rafaela Santos, Flávia Tobaldini-Valério, Terezinha Svidzinski, Marcos Bruschi, Bruno Sarmento, M Beatriz P P Oliveira, Francisca Rodrigues
Propolis is a natural adhesive resinous compound produced by honeybees to protect hives from bacteria and fungi, being extremely expensive for food industry. During propolis production, a resinous by-product is formed. This resinous waste is currently undervalued and underexploited. Accordingly, in this study the proximate physical and chemical quality, as well as the antioxidant activity, radical scavenging activity and cell viability of this by-product were evaluated and compared with propolis in order to boost new applications in food and pharmaceutical industries...
March 2018: Food Research International
Antonella Borrelli, Patrizia Bonelli, Franca Maria Tuccillo, Ira D Goldfine, Joseph L Evans, Franco Maria Buonaguro, Aldo Mancini
Non-alcoholic fatty liver disease (NAFLD) represents the most common chronic liver disease in industrialized countries. NAFLD progresses through the inflammatory phase of non-alcoholic steatohepatitis (NASH) to fibrosis and cirrhosis, with some cases developing liver failure or hepatocellular carcinoma (HCC). Liver biopsy remains the gold standard approach to a definitive diagnosis of NAFLD and the distinction between simple steatosis and NASH. The pathogenesis of NASH is still not clear. Several theories have been proposed ranging from the "Two Hit Theory" to the "Multiple Hit Theory"...
January 27, 2018: Redox Biology
Zimu Xu, Cheng Cheng, Jie Shen, Yan Lan, Shuheng Hu, Wei Han, Paul K Chu
The direct inactivation effects of an atmospheric pressure direct current (DC) air plasma against planktonic Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in aqueous solution are investigated in vitro. Upon plasma treatment, extensively analyses on cell culturability, metabolic capacity, membrane integrity, surface morphology, cellular proteins, nucleic acids and intracellular reactive oxygen species (ROS) for both bacterial species were carried out and significant antimicrobial effects observed...
January 30, 2018: Bioelectrochemistry
Erik R Zinser
Hydrogen peroxide (HOOH) is a reactive oxygen species, derived from molecular oxygen, that is capable of damaging microbial cells. Surprisingly, the HOOH defense systems of some aerobes in the oxygenated marine environments are critically depleted, relative to model aerobes. For instance, the gene encoding catalase is absent in the numerically-dominant photosynthetic cyanobacterium, Prochlorococcus. Accordingly, Prochlorococcus is highly susceptible to HOOH when exposed as pure cultures. Pure cultures do not exist in the marine environment, however...
February 6, 2018: Environmental Microbiology Reports
Jun Kong, Meisheng Wei, Guifen Li, Rong Lei, Yanhong Qiu, Chenguang Wang, Zhi-Hong Li, Shuifang Zhu
Cucumber Mosaic Virus (CMV) has a small RNA genome that encodes a limited number of proteins, but can infect many plant species, including Arabidopsis thaliana and Nicotiana benthamiana. Virus proteins thus have multiple means of conferring their pathogenicity during the infection process. However, the pathogenic mechanism of CMV remains unclear. Here we discovered that the expression of the CMV movement protein (MP) in A. thaliana and N. benthamiana can suppress reactive oxygen species (ROS) production triggered by multiple pathogen-associated molecular patterns (PAMPs), such as bacteria-derived peptide flg22, elf18, and fungal-derived chitin...
February 3, 2018: Biochemical and Biophysical Research Communications
Janet Z Liu, Syed R Ali, Ethan Bier, Victor Nizet
Bacillus anthracis, the causative agent of anthrax, has been a focus of study in host-pathogen dynamics since the nineteenth century. While the interaction between anthrax and host macrophages has been extensively modeled, comparatively little is known about the effect of anthrax on the immune function of neutrophils, a key frontline effector of innate immune defense. Here we showed that depletion of neutrophils significantly enhanced mortality in a systemic model of anthrax infection in mice. Ex vivo, we found that freshly isolated human neutrophils can rapidly kill anthrax, with specific inhibitor studies showing that phagocytosis and reactive oxygen species (ROS) generation contribute to this efficient bacterial clearance...
2018: Frontiers in Cellular and Infection Microbiology
Saurabh Mishra, Abhijit Maiti
The industrial dye-contaminated wastewater has been considered as the most complex and hazardous in terms of nature and composition of toxicants that can cause severe biotic risk. Reactive azo, anthroquinone and triphenylmethane dyes are mostly used in dyeing industries; thus, the unfixed hydrolysed molecules of these dyes are commonly found in wastewater. In this regard, bacterial species have been proved to be highly effective to treat wastewater containing reactive dyes and heavy metals. The bio-decolourisation of dye occurs either by adsorption or through degradation in bacterial metabolic pathways under optimised environmental conditions...
January 30, 2018: Environmental Science and Pollution Research International
Xiao-Yong Fan, Bi-Kui Tang, Yuan-Yuan Xu, Ang-Xuan Han, Kun-Xiong Shi, Yong-Kai Wu, Yu Ye, Mei-Li Wei, Chen Niu, Ka-Wing Wong, Guo-Ping Zhao, Liang-Dong Lyu
Growing evidence shows that generation of reactive oxygen species (ROS) derived from antibiotic-induced metabolic perturbation contribute to antibiotic lethality. However, our knowledge of the mechanisms by which antibiotic-induced oxidative stress actually kills cells remains elusive. Here, we show that oxidation of dCTP underlies ROS-mediated antibiotic lethality via induction of DNA double-strand breaks (DSBs). Deletion of mazG-encoded 5-OH-dCTP-specific pyrophosphohydrolase potentiates antibiotic killing of stationary-phase mycobacteria, but did not affect antibiotic efficacy in exponentially growing cultures...
January 30, 2018: Proceedings of the National Academy of Sciences of the United States of America
Alla Zamyatina
The immediate immune response to infection by Gram-negative bacteria depends on the structure of a lipopolysaccharide (LPS, also known as endotoxin), a complex glycolipid constituting the outer leaflet of the bacterial outer membrane. Recognition of picomolar quantities of pathogenic LPS by the germ-line encoded Toll-like Receptor 4 (TLR4) complex triggers the intracellular pro-inflammatory signaling cascade leading to the expression of cytokines, chemokines, prostaglandins and reactive oxygen species which manifest an acute inflammatory response to infection...
2018: Beilstein Journal of Organic Chemistry
Martin Broberg, James Doonan, Filip Mundt, Sandra Denman, James E McDonald
BACKGROUND: Britain's native oak species are currently under threat from acute oak decline (AOD), a decline-disease where stem bleeds overlying necrotic lesions in the inner bark and larval galleries of the bark-boring beetle, Agrilus biguttatus, represent the primary symptoms. It is known that complex interactions between the plant host and its microbiome, i.e. the holobiont, significantly influence the health status of the plant. In AOD, necrotic lesions are caused by a microbiome shift to a pathobiome consisting predominantly of Brenneria goodwinii, Gibbsiella quercinecans, Rahnella victoriana and potentially other bacteria...
January 30, 2018: Microbiome
Fen Wan, Linggen Kong, Haichun Gao
It is well established that OxyR functions as a transcriptional activator of the peroxide stress response in bacteria, primarily based on studies on Escherichia coli. Recent investigations have revealed that OxyRs of some other bacteria can regulate gene expression through both repression and activation or repression only; however, the underlying mechanisms remain largely unknown. Here, we demonstrated in g-proteobacterium Shewanella oneidensis that regulation of OxyR on expression of major catalase gene katB in a dual-control manner through interaction with a single site in the promoter region...
January 24, 2018: Journal of Biological Chemistry
Rusi Lata, Sandip Chowdhury, Surendra K Gond, James F White
Endophytes are microorganisms including bacteria and fungi that survive within healthy plant tissues and promote plant growth under stress. This review focuses on the potential of endophytic microbes that induce abiotic stress tolerance in plants. How endophytes promote plant growth under stressful conditions, like drought and heat, high salinity and poor nutrient availability will be discussed. The molecular mechanisms for increasing stress tolerance in plants by endophytes include induction of plant stress genes as well as biomolecules like reactive oxygen species (ROS) scavengers...
January 22, 2018: Letters in Applied Microbiology
Surbhi Goel, Prashant Mishra
The present study was aimed to investigate the antibacterial potential and antibiofilm activity of thymoquinone and its mechanism of action. Antibacterial activity of thymoquinone was studied using minimum inhibitory concentration, minimum bactericidal concentration, time-kill assay, and post-antibiotic effect. Thymoquinone exhibited antibacterial activity against both Gram-negative and Gram-positive bacteria. In this study, the minimum inhibitory concentration was found to be in the range of 1.56 to 100 μg/ml...
February 2018: Applied Microbiology and Biotechnology
Shanshan Liu, Huanxiang Yuan, Haotian Bai, Pengbo Zhang, Fengting Lv, Libing Liu, Zhihui Dai, Jianchun Bao, Shu Wang
The employment of physical light source in clinical photodynamic therapy (PDT) system endow it with crucial defect in the treatment of deeper tissue lesions due to the limited penetration depth of light in biological tissues. In this work, we constructed for the first time an electric driven luminous system based on electrochemiluminescence (ECL) for killing pathogenic bacteria, where ECL is used for the excitation of photosensitizer instead of physical light source to produce reactive oxygen species (ROS)...
January 21, 2018: Journal of the American Chemical Society
Florent Le Guern, Tan-Sothea Ouk, Catherine Ouk, Regis Vanderesse, Yves Champavier, Emilie Pinault, Vincent Sol
In order to highlight the potential of photodynamic antimicrobial chemotherapy in case of infections by antibiotic resistant-strains, a new antimicrobial peptide conjugate has been synthesized, consisting of a derivative of polymyxin B and a cationic porphyrin covalently attached together to a spacer. A polymyxin-derived moiety was subjected to a primary structural modification in the replacement of four diaminobutyrate residues with lysine ones. This modification was done in order to strongly reduce bactericidal activity, with the aim to eliminate the potential rise of polymyxin-resistant strains...
January 11, 2018: ACS Medicinal Chemistry Letters
Fei Xu, Ying Li, Justen Ahmad, Yonggang Wang, Dorothy Scott, Jaroslav G Vostal
Photodynamic treatment combining light and a photosensitizer molecule can be an effective method to inactivate pathogenic bacteria. This study identified vitamin K5 as an efficient photosensitizer for ultraviolet light A (UVA)-induced bacterial inactivation. Six bacterial species, Bacillus cereus (vegetative form), Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, and two species of antibiotic-resistant bacteria, Pseudomonas aeruginosa* and Staphylococcus aureus*, were suspended in aqueous solutions with or without vitamin K5 and exposed to UVA irradiation...
January 15, 2018: FEMS Microbiology Letters
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