Article
Biochemistry & Molecular Biology
Jovana Bakovic, Bess Yi Kun Yu, Daniel Silva, Maria Baczynska, Sew Yeu Peak-Chew, Amy Switzer, Lynn Burchell, Sivaramesh Wigneshweraraj, Muralidharan Vandanashree, Balasubramanian Gopal, Valeriy Filonenko, Mark Skehel, Ivan Gout
Summary: S. aureus AgrA is modified by covalent binding of CoA in response to oxidative or metabolic stress, leading to decreased DNA-binding activity.
Article
Medicine, Research & Experimental
Balamurugan Palaniappan, Adline Princy Solomon, David C. Raj
Summary: This study focused on targeting the quorum sensing regulator AgrA of Staphylococcus aureus to reduce bacterial virulence through drug repurposing. The results showed that bumetanide effectively inhibited AgrA and reduced the expression of virulence genes in S. aureus. In vivo studies demonstrated the efficacy of bumetanide in controlling ulcer development and promoting wound healing in mice.
Article
Biochemistry & Molecular Biology
Amitha Joy, V. Febin Seethi, Marria C. Cyriac, Jasmin Habeeb, Sunisha Sudhakaran, Shaheen Shah
Summary: Staphylococcus aureus is a bacterium that causes various infections. The prevalence of antibiotic resistant strains has diminished treatment effectiveness. An alternate strategy is using anti-virulence methods. Prediction models for AgrA inhibitors were developed using a Machine Learning algorithm and pharmacophore modelling.
JOURNAL OF BIOMOLECULAR STRUCTURE & DYNAMICS
(2023)
Article
Microbiology
Qian Huang, Yihui Xie, Ziyu Yang, Danhong Cheng, Lei He, Hua Wang, Qian Liu, MinZZ Li
Summary: In Staphylococcus aureus, the accessory gene regulator (agr) quorum-sensing system is crucial for biofilm formation, with AgrC playing a key role in sensing and activating the system. A study showed that a naturally occurring single amino acid substitution in the AgrC cytoplasmic loop significantly affected biofilm formation and Agr activity. The deletion of certain cytoplasmic and extracellular loops of AgrC completely abolished Agr activity and growth-dependence on the agr system induction.
JOURNAL OF MICROBIOLOGY
(2021)
Article
Veterinary Sciences
Bruno Toledo-Silva, Fernando Nogueira de Souza, Sofie Piepers, Kristien Mertens, Freddy Haesebrouck, Sarne De Vliegher
Summary: Communication via quorum sensing between non-aureus staphylococci and Staphylococcus aureus in the bovine mammary gland is underexplored. Results showed that NAS can regulate the QS system of S. aureus, with S. chromogenes and S. simulans being more effective than S. epidermidis. NAS metabolites and supernatant had greater regulatory activity over S. aureus virulence genes than NAS cells themselves.
VETERINARY RESEARCH
(2021)
Article
Biochemistry & Molecular Biology
Patricia Coelho, Joana Oliveira, Iva Fernandes, Paula Araujo, Ana Rita Pereira, Paula Gameiro, Lucinda J. Bessa
Summary: Bacterial quorum sensing is a communication system that regulates various bacterial mechanisms, including biofilm formation. Targeting microbial QS is considered as an alternative strategy to combat multidrug-resistant pathogens, with phytochemicals showing potential QS interference activity. An extract and a compound of bioinspired origin were tested for their ability to inhibit biofilm formation and interfere with QS-related gene expression in Pseudomonas aeruginosa and Staphylococcus aureus. The results showed significant effects on biofilm formation and gene expression in S. aureus strains, suggesting potential therapeutic applications for these anti-QS molecules.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Microbiology
Soyoun Park, Adam Classen, Hanny Maeva Gohou, Roberto Maldonado, Emily Kretschmann, Chloe Duvernay, Geun-Joong Kim, Jennifer Ronholm
Summary: A new plasmid-based screening method was used to identify bacteria with antagonistic activity against antibiotic-resistant Staphylococcus aureus. By creating stable recombinant plasmids carrying reporter proteins under the control of a S. aureus promoter, the study successfully identified commensal bacteria with growth-inhibiting and quorum-quenching activity. This approach offers a promising strategy for developing probiotic drugs and therapeutics for S. aureus infections in both humans and animals.
Article
Biotechnology & Applied Microbiology
Yufang Li, Shijun Li, Kun Yang, Rongxiang Guo, Xin Zhu, Yanan Shi, Aixiang Huang
Summary: The study revealed the significant antibiofilm activity of a novel milk-derived antimicrobial peptide BCp12 against Staphylococcus aureus through interfering with the agr QS system, demonstrating its potential as a novel antibiofilm agent in the food industry.
JOURNAL OF APPLIED MICROBIOLOGY
(2022)
Review
Biochemistry & Molecular Biology
Bhawandeep Kaur, Jeena Gupta, Sarika Sharma, Divakar Sharma, Sandeep Sharma
Summary: Staphylococcus aureus is a common pathogen causing various infections, with Methicillin-Resistant Staphylococcus aureus (MRSA) being particularly concerning. The primary antimicrobial resistance mechanisms in S. aureus involve efflux pumps and biofilm formation, with quorum sensing and drug efflux playing crucial roles. Efflux pump inhibitors (EPIs) have been identified as a promising approach to combat bacterial resistance, by inhibiting drug efflux mechanisms and transport of quorum sensing signalling molecules.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Biochemistry & Molecular Biology
Macauley J. Green, Ewan J. Murray, Paul Williams, Amir M. Ghaemmaghami, Jonathan W. Aylott, Philip M. Williams
Summary: Under low-shear modeled microgravity conditions, Staphylococcus aureus exhibited a colonization phenotype instead of a pathogenic one, due to reduced production of autoinducing peptide signal molecules.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Biochemistry & Molecular Biology
Michael Otto
Summary: Staphylococcus aureus is a significant pathogen responsible for numerous infections and causing high mortality rates in hospitalized patients. The emergence of antibiotic resistance, particularly methicillin-resistant S. aureus (MRSA), has prompted the exploration of alternative anti-virulence strategies. Targeting the S. aureus accessory gene regulator (Agr) quorum-sensing system, a key regulator of virulence, has been proposed as the most common anti-virulence approach. However, there is limited in vivo evidence for the efficacy of Agr inhibition, and potential concerns regarding biofilm formation and functional implications on invasive S. aureus infections.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Microbiology
Norhan H. Mahdally, Riham F. George, Mona T. Kashef, Medhat Al-Ghobashy, Fathia E. Murad, Ahmed S. Attia
Summary: The development of a compound named staquorsin as an Agr inhibitor for Staphylococcus aureus showed promising results in inhibiting virulence factors without affecting bacterial viability. In in vitro and in vivo testing, the compound effectively controlled the infection and demonstrated potential as a drug candidate against S. aureus.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Microbiology
Adam Benedict Turner, Erik Gerner, Rininta Firdaus, Maite Echeverz, Maria Werthen, Peter Thomsen, Sofia Almqvist, Margarita Trobos
Summary: The study investigated the impact of sodium salicylate (NaSa) on Staphylococcus aureus quorum sensing (QS), virulence production, and biofilm formation. NaSa was found to downregulate the agr QS system, leading to decreased toxin secretion and increased biofilm formation. The effect of NaSa on biofilm formation was dependent on the strain and material surface. The study suggests that NaSa could be a potential alternative or adjuvant to traditional antibiotics.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Immunology
Quang Vinh Ngo, Larissa Faass, Aline Saehr, Dagmar Hildebrand, Tatjana Eigenbrod, Klaus Heeg, Dennis Nurjadi
Summary: Staphylococcus aureus can cause infections, but it can also colonize the skin without inducing inflammatory response in some individuals. On the other hand, Staphylococcus epidermidis can permanently colonize the skin without activating skin inflammation. Our study suggests that the internalization of S. aureus and the subsequent sensing of bacterial nucleic acid are essential for initiating inflammatory response in skin cells.
FRONTIERS IN IMMUNOLOGY
(2022)
Article
Microbiology
Morgan M. Severn, Michael R. Williams, Ali Shahbandi, Zoie L. Bunch, Laurie M. Lyon, Amber Nguyen, Livia S. Zaramela, Daniel A. Todd, Karsten Zengler, Nadja B. Cech, Richard L. Gallo, Alexander R. Horswill
Summary: Human skin is home to a variety of commensal bacteria, including Staphylococcus hominis, which plays an important role in preventing Staphylococcus aureus colonization and infection. It produces multiple signaling molecules that inhibit the virulence factor regulation system of S. aureus and other related species. Synthetic versions of these molecules have shown protective effects against S. aureus-associated skin injuries in animal models.
Article
Physics, Applied
S. K. Srivastava
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2020)
Article
Physics, Applied
S. K. Srivastava, Aakansha, S. S. Baro, B. Narzary, D. R. Basumatary, R. Brahma, S. Ravi
Summary: Pure SnO2, Sn0.94Co0.06O2, Sn0.91Co0.06Ag0.03O2, and Sn(0.88)Co(0.06)Ag(0.06)O(2) compounds were synthesized via solid-state reaction method, all exhibiting a single-phase tetragonal rutile structure. Temperature variation of magnetization measurements revealed different magnetic behaviors, including diamagnetic, ferromagnetic to paramagnetic transition, and double ferromagnetic transitions. Magnetic hysteresis curves showed an increase in coercivity and saturation magnetization values with higher (Co-Ag) co-doping concentrations. The observed ferromagnetism was attributed to exchange interaction via oxygen vacancies between Co(2+) and Co(3+) ions.
JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
(2021)
Review
Medicine, Research & Experimental
Rehan Ahmad, Jaikee Kumar Singh, Amoolya Wunnava, Omar Al-Obeed, Maha Abdulla, Sandeep Kumar Srivastava
Summary: Colorectal cancer is the third most common cancer globally, with prevention methods being crucial for management. It is primarily caused by unhealthy lifestyle habits and genetic mutations, with a rising trend among young individuals.
INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE
(2021)
Review
Oncology
Maha-Hamadien Abdulla, Disha Agarwal, Jaikee Kumar Singh, Thamer Bin Traiki, Manoj Kumar Pandey, Rehan Ahmad, Sandeep Kumar Srivastava
Summary: Colorectal cancer is the second most common malignancy causing cancer-related mortality globally, and the balance between microbiomes and epithelial cells of the human body is essential for normal physiology. An imbalance in the microbiome is prominent in the guts of patients with CRC, where 'bad' microbes increase and 'good' microbes decrease, leading to a pro-inflammatory state and potentially contributing to cancer progression.
INTERNATIONAL JOURNAL OF ONCOLOGY
(2021)
Article
Chemistry, Physical
L. Chouhan, Shantanu Kumar Panda, S. Bhattacharjee, B. Das, A. Mondal, B. N. Parida, R. Brahma, Murli Kumar Manglam, M. Kar, G. Bouzerar, S. K. Srivastava
Summary: Investigated the structural, micro-structural, optical, magnetic, and electrical properties of Ag doped SnO2 compounds, revealing ferromagnetism, uniform spherical nanoparticle morphology, band-gap narrowing, and p-type conductivity with increasing hole concentration due to Ag doping. The observed enhancement in dielectric constant and ac conductivity with increased Ag concentration suggests charge carriers' hopping as the responsible transport mechanism. The ferromagnetism observed is attributed to p-d hybridization between O and Ag ions.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Electrical & Electronic
L. Chouhan, G. Bouzerar, S. K. Srivastavat
Summary: The study investigated the crystal structure, micro-structure, and magnetic properties of Li-doped ZnO compounds, revealing that Li-doping induces room temperature ferromagnetism with ultra-soft coercivity. XRD patterns and SEM images confirmed the high crystallinity and uniform morphology of the doped compounds.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Physics, Condensed Matter
R. Hussain, Aakansha, S. Ravi, S. K. Srivastava
Summary: In this work, the magnetic properties of Co/Ni multilayers-based bit patterned media were studied, revealing that nano-bumps with N = 20 bi-layers exhibit perpendicular magnetic anisotropy with an anisotropy constant of 1.90 x 10(5) erg/cm(3). Magnetic properties parameters on nano-bumps were compared with those deposited on a flat Si substrate, showing higher H-C values for Co/Ni nano-bumps but lower squareness (M-R/M-S) and K-u values.
SOLID STATE COMMUNICATIONS
(2021)
Article
Medicine, Research & Experimental
Sandeep K. Srivastava, Lauren L. Truitt, Chuanfeng Wu, Adam Glaser, Daniel J. Nolan, Michael Ginsberg, Diego A. Espinoza, Samson Koelle, Idalia M. Yabe, Kyung-Rok Yu, Sogun Hong, Stephanie Sellers, Allen Krouse, Aylin Bonifacino, Mark Metzger, Pradeep K. Dagur, Robert E. Donahue, Cynthia E. Dunbar, Sandhya R. Panch
Summary: The development of ex vivo HSPC expansion platforms is crucial for improving engraftment ability in cord blood grafts and for gene therapy applications. In a rhesus macaque model, the impact of ex vivo expansion on HSPCs was studied, showing comparable short and long-term engraftment between expanded and non-expanded HSPCs. The study demonstrates the potential of this model for testing ex vivo HSPC expansion platforms, especially for gene therapy applications, due to its ability to mimic human HSPC kinetics and analyze post-transplant clonal patterns effectively.
MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT
(2021)
Article
Engineering, Electrical & Electronic
L. Chouhan, G. Bouzerar, S. K. Srivastava
Summary: The study investigated Mg-doped TiO2 materials and found that 6% Mg-doped TiO2 exhibits ferromagnetism with a transition temperature of 180.2 K. The material also shows low-temperature magnetic irreversibility, indicating the presence of competing antiferromagnetic and ferromagnetic phases.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Review
Biochemical Research Methods
Aneesa Fasim, Veena S. More, Sunil S. More
Summary: Enzymes are biocatalysts that accelerate chemical reactions to produce valuable products. Biotechnology has expanded the use of traditional enzymes into industries such as food, beverage, personal care, and agriculture. In recent years, there has been exponential growth of enzyme applications in the biotech industry, especially hydrolytic microbial enzymes used in industrial bioprocesses.
CURRENT OPINION IN BIOTECHNOLOGY
(2021)
Review
Food Science & Technology
Varsha Sahni, Sandeep Srivastava, Rijwan Khan
Summary: Artificial intelligence is playing an increasingly important role in the field of food processing and quality assurance, with the ability to learn from experience, analyze data, and perform tasks with improved accuracy and efficiency.
JOURNAL OF FOOD QUALITY
(2021)
Article
Biotechnology & Applied Microbiology
H. K. Manjushree, Prakruti P. Acharya, Ganapati Bhat, Sunil S. More, Aneesa Fasim
Summary: This study examined the bioactive and wound healing properties of collagen hydrolysate derived from Piaractus brachypomus fish skin waste and found that the recycled collagen hydrolysate has potent wound healing ability.
JOURNAL OF BIOACTIVE AND COMPATIBLE POLYMERS
(2023)
Article
Microbiology
Sandeep Srivastava, Michael J. Holmes, Michael W. White, William J. Sullivan Jr
Summary: Cats are the only host for the sexually stage of Toxoplasma gondii, and a better understanding of the proteins controlling the parasite's life cycle stage transitions is needed for the development of new therapies for toxoplasmosis treatment and transmission prevention.
Article
Multidisciplinary Sciences
Mary Arpana, Seema S. Rathore, Ajay Nair, Sunil S. More, Aneesa Fasim
Summary: In this study, a bacterial strain identified as Pseudomonas sp. 13159349 was isolated from fruit market soils and found to produce polygalacturonase (PGase) with pectinolytic activity confirmed by TLC analysis. The production of thermostable and alkalophilic PGase was optimized using SSF, Plackett-Burman design (PB), and response surface methodology (RSM), with wheat bran as the most effective agricultural waste substrate. Statistical optimization using PB design revealed that pH, inoculum size, incubation time, and temperature had a positive effect on production. RSM analysis identified the optimal conditions for maximum production of the enzyme. Through these methods, a significant 5.2-fold increase in PGase output was achieved, making it a cost-effective bioprocess.
Article
Biology
Mary Arpana, Aneesa Fasim, H. K. Manjushree, Sunil S. More
Summary: The present study focuses on the characterization of a highly alkalophilic and thermostable polygalacturonase (PGase) from Pseudomonas sp. 13,159,349 and its potential use in olive-oil extraction. The PGase enzyme was produced using wheat bran solid substrate fermentation (SSF) media and purified by gel permeation chromatography. The enzyme exhibited optimum activity at pH 9 and 45 - 50 degrees C and retained stability at alkaline pH and high temperatures. The enzyme's kinetic parameters with pectin substrate were determined, and the effects of metal ions and surfactants on enzyme activity were investigated. Treatment with PGase significantly increased olive oil output and polyphenol content in olive paste.
