Read by QxMD icon Read

Bacteria cell membrane

Ling Xu, Dan Naylor, Zhaobin Dong, Tuesday Simmons, Grady Pierroz, Kim K Hixson, Young-Mo Kim, Erika M Zink, Kristin M Engbrecht, Yi Wang, Cheng Gao, Stephanie DeGraaf, Mary A Madera, Julie A Sievert, Joy Hollingsworth, Devon Birdseye, Henrik V Scheller, Robert Hutmacher, Jeffery Dahlberg, Christer Jansson, John W Taylor, Peggy G Lemaux, Devin Coleman-Derr
Drought stress is a major obstacle to crop productivity, and the severity and frequency of drought are expected to increase in the coming century. Certain root-associated bacteria have been shown to mitigate the negative effects of drought stress on plant growth, and manipulation of the crop microbiome is an emerging strategy for overcoming drought stress in agricultural systems, yet the effect of drought on the development of the root microbiome is poorly understood. Through 16S rRNA amplicon and metatranscriptome sequencing, as well as root metabolomics, we demonstrate that drought delays the development of the early sorghum root microbiome and causes increased abundance and activity of monoderm bacteria, which lack an outer cell membrane and contain thick cell walls...
April 16, 2018: Proceedings of the National Academy of Sciences of the United States of America
Xiaofang Luo, Yanjun Liu, Zuodong Qin, Zhiyuan Jin, Liting Xu, Yang Liu, Linyan Cao, Fulin He, Xiaohong Gu, Xiaoping Ouyang
Antibiotic resistance is a growing threat to human health. More than anything else, multidrug-resistant gram-negative bacteria pose the biggest challenge to healthcare, which is predominantly due to the lack of effective therapeutic options. In the present study, we investigated the activities of peptides HX-12A, HX-12B and HX-12C against MDRAB and MDRKP isolates in vitro. Those three peptides displayed high antibacterial activities and rapid bactericidal effects against MDRAB and MDRKP isolates. Additionally, the peptides retained their activity even being present in pH 6...
March 1, 2018: Journal of Biomedical Nanotechnology
Ranjani Dhakshinamoorthy, Moritz Bitzhenner, Pierre Cosson, Thierry Soldati, Matthias Leippe
Due to their archaic life style and microbivor behavior, amoebae may represent a source of antimicrobial peptides and proteins. The amoebic protozoon Dictyostelium discoideum has been a model organism in cell biology for decades and has recently also been used for research on host-pathogen interactions and the evolution of innate immunity. In the genome of D. discoideum , genes can be identified that potentially allow the synthesis of a variety of antimicrobial proteins. However, at the protein level only very few antimicrobial proteins have been characterized that may interact directly with bacteria and help in fighting infection of D...
2018: Frontiers in Cellular and Infection Microbiology
Tamara Reyes-Robles, Rebecca S Dillard, Lynne S Cairns, Cecilia A Silva-Valenzuela, Max Housman, Afsar Ali, Elizabeth R Wright, Andrew Camilli
Novel preventatives could help in efforts to limit Vibrio cholerae infection and the spread of cholera. Bacteriophage (or phage) treatment has been proposed to be an alternative intervention, given the rapid replication of virulent phages, prey specificity, and relative ease of finding new virulent phages. Phage tropism is dictated in part by the presence of phage receptors on the bacterial surface. While many phages that can kill V. cholerae have been isolated, whether this pathogen is able to defend itself by neutralizing phage binding is unknown...
April 16, 2018: Journal of Bacteriology
Margareth Sidarta, Dongdong Li, Lars Hederstedt, Ewa Bukowska-Faniband
SpoVD and PBP4b are structurally very similar high molecular weight, class B, penicillin-binding proteins produced early during sporulation in Bacillus subtilis SpoVD is known to be essential for endospore cortex synthesis and thereby production of heat-resistant spores. The role of PBP4b is still enigmatic. Both proteins are synthesized in the cytoplasm of the mother cell. PBP4b remains in the cytoplasmic membrane of the mother cell whereas SpoVD accumulates in the forespore outer membrane. By the use of SpoVD/PBP4b chimeras with swapped protein domains we show that the N-terminal part of SpoVD, containing the single transmembrane region, determines forespore targeting of the protein...
April 16, 2018: Journal of Bacteriology
Christopher M Stead, Diane C Cockrell, Paul A Beare, Heather E Miller, Robert A Heinzen
BACKGROUND: Many gram-negative bacteria produce an outer membrane phospholipase A (PldA) that plays an important role in outer membrane function and is associated with virulence. RESULTS: In the current study, we characterized a pldA mutant of Coxiella burnetii, an intracellular gram-negative pathogen and the agent of human Q fever. The C. burnetti pldA open reading frame directs synthesis of a protein with conserved PldA active site residues. A C. burnetii ΔpldA deletion mutant had a significant growth defect in THP-1 macrophages, but not axenic medium, that was rescued by complementation...
April 16, 2018: BMC Microbiology
Liping Feng, Terrence K Allen, William P Marinello, Amy P Murtha
BACKGROUND: Preterm premature rupture of membranes (PPROM) is a leading contributor to maternal and neonatal morbidity and mortality. Epidemiologic and experimental studies have demonstrated that thrombin causes fetal membrane weakening and subsequently PPROM. Although blood is suspected as the likely source of thrombin in fetal membranes and amniotic fluid of patients with PPROM, this has not been proven. Ureaplasma Parvum (U. parvum) is emerging as a pathogen involved in prematurity, including PPROM, but until now, prothrombin production directly induced by bacteria in fetal membranes has not been described...
April 13, 2018: American Journal of Obstetrics and Gynecology
Monisha Pathania, Silvia Acosta-Gutierrez, Satya Pratyusha Bhamidimarri, Arnaud Baslé, Mathias Winterhalter, Matteo Ceccarelli, Bert van den Berg
The outer membranes (OM) of many Gram-negative bacteria contain general porins, which form nonspecific, large-diameter channels for the diffusional uptake of small molecules required for cell growth and function. While the porins of Enterobacteriaceae (e.g., E. coli OmpF and OmpC) have been extensively characterized structurally and biochemically, much less is known about their counterparts in Vibrionaceae. Vibrio cholerae, the causative agent of cholera, has two major porins, OmpU and OmpT, for which no structural information is available despite their importance for the bacterium...
April 3, 2018: Structure
Jiajun Wang, Shuli Chou, Zhanyi Yang, Yang Yang, Zhihua Wang, Jing Song, Xiujing Dou, Anshan Shan
Antimicrobial peptides are an important weapon against invading pathogens and are potential candidates as novel antibacterial agents, but their antifungal activities are not fully developed. In this study, a set of imperfectly amphipathic peptides was developed based on the imperfectly amphipathic palindromic structure Rn(XRXXXRX)Rn (n = 1,2; X represents L, I, F, or W), and the engineered peptides exhibited high antimicrobial activities against all fungi and bacteria tested (including fluconazole-resistant Candida albicans), with geometric mean (GM) MICs ranging from 2...
April 12, 2018: Journal of Medicinal Chemistry
Norberto Gonzalez-Juarbe, Kelley M Bradley, Ashleigh N Riegler, Luis F Reyes, Terry Brissac, Sang-Sang Park, Marcos I Restrepo, Carlos J Orihuela
Pore-forming toxins are the most common virulence factor in pathogenic bacteria. They lead to membrane permeabilization and cell death. Herein, we show that respiratory epithelial cells (REC) undergoing bacterial pore-forming toxin (PFT)-induced necroptosis simultaneously experienced caspase activation independently of RIPK3. MLKL deficient REC treated with a pan-caspase inhibitor were protected in an additive manner against PFT-induced death. Subsequently, cleaved versions of caspases-2, -4 and -10 were detected within REC undergoing necroptosis by immunoblots and monoclonal antibody staining...
April 11, 2018: Scientific Reports
Xiaogang Wang, Christopher D Thompson, Christopher Weidenmaier, Jean C Lee
Secretion of extracellular vesicles (EVs), a process common to eukaryotes, archae, and bacteria, represents a secretory pathway that allows cell-free intercellular communication. Microbial EVs package diverse proteins and influence the host-pathogen interaction, but the mechanisms underlying EV production in Gram-positive bacteria are poorly understood. Here we show that EVs purified from community-associated methicillin-resistant Staphylococcus aureus package cytosolic, surface, and secreted proteins, including cytolysins...
April 11, 2018: Nature Communications
Bin Liu, Mikko Karttunen
Daptomycin is a cyclic lipopeptide effective against multidrug Gram-positive bacteria. Despite having a net negative charge, it is selective against negatively charged bacterial membranes. It has been established that daptomycin's antibiotic activity is based on directly targeting the bacterial membranes and that this antibacterial activity depends on calcium ions. Importantly, however, both the precise role of ions and the physical mechanisms responsible for daptomycin's action remain poorly understood. We investigate these issues using three types of molecular dynamics simulations: umbrella sampling free energy calculations for a single daptomycin, unbiased simulations for daptomycin tetramers, and unbiased simulations of micellation of daptomycin both in the absence and presence of calcium ions...
April 5, 2018: Biochimica et Biophysica Acta
Justine Guerin, Claire Soligot, Jennifer Burgain, Marion Huguet, Gregory Francius, Sofiane El-Kirat-Chatel, Faustine Gomand, Sarah Lebeer, Yves Le Roux, Frederic Borges, Joël Scher, Claire Gaiani
Milk is the most popular matrix for the delivery of lactic acid bacteria, but little is known about how milk impacts bacterial functionality. Here, the adhesion mechanisms of Lactobacillus rhamnosus GG (LGG) surface mutants to a milk component, the milk fat globule membrane (MFGM), were compared using atomic force microscopy (AFM). AFM results revealed the key adhesive role of the LGG SpaCBA pilus in relation to MFGM. A LGG mutant without exopolysaccharides but with highly exposed pili improved the number of adhesive events between LGG and MFGM compared to LGG wild type (WT)...
March 28, 2018: Colloids and Surfaces. B, Biointerfaces
K T Shalumon, Chialin Sheu, Chih-Hao Chen, Shih-Heng Chen, Gils Jose, Chang-Yi Kuo, Jyh-Ping Chen
The possibility of endowing an electrospun anti-adhesive barrier membrane with multi-functionality, such as lubrication, prevention of fibroblast attachment and anti-infection and anti-inflammation properties, is highly desirable for the management of post-surgical tendon adhesion. To this end, we fabricated core-shell nanofibrous membranes (CSNMs) with embedded silver nanoparticles (Ag NPs) in the poly(ethylene glycol) (PEG)/poly(caprolactone) (PCL) shell and hyaluronic acid (HA)/ibuprofen in the core. HA imparted a lubrication effect for smooth tendon gliding and reduced fibroblast attachment, while Ag NPs and ibuprofen functioned as anti-infection and anti-inflammation agents, respectively...
April 4, 2018: Acta Biomaterialia
Qian Li, Manuel Montalban-Lopez, Oscar P Kuipers
Lantibiotics are ribosomally synthesized and posttranslationally modified antimicrobial compounds containing lanthionine and methyl-lanthionine residues. Nisin, one of the most extensively studied and used lantibiotics, has been shown to display a very potent activity against Gram-positive bacteria and stable resistance is rarely observed. By binding to lipid II and forming pores in the membrane, nisin can cause efflux of cellular constituents and inhibit cell wall biosynthesis. However, the activity of nisin against Gram-negative bacteria is much lower than that against Gram-positive bacteria, mainly because lipid II is located at the inner-membrane and the rather impermeable outer-membrane in Gram-negative bacteria prevents nisin from reaching lipid II...
April 6, 2018: Applied and Environmental Microbiology
Hee Geun Park, Kwang Sik Lee, Bo Yeon Kim, Hyung Joo Yoon, Yong Soo Choi, Kyung Yong Lee, Hu Wan, Jianhong Li, Byung Rae Jin
Honeybee (Apis mellifera) egg-yolk protein vitellogenin (Vg) plays roles in immunity, antioxidation, and life span beyond reproduction, but it also acts as an allergen Api m 12 in venom. Here we established antimicrobial and antioxidant roles of honeybee Vg in the body and venom. Using the cDNA encoding Vg identified from Asiatic honeybee (A. cerana) workers, recombinant A. cerana Vg (AcVg) protein of approximately 180 kDa was produced in baculovirus-infected insect cells. In A. cerana worker bees, AcVg was expressed in the fat body and venom gland and was present in the secreted venom...
April 2, 2018: Developmental and Comparative Immunology
Sahira Nsayef Muslim, Israa M S Al-Kadmy, Ibtesam Ghadban Auda, Alaa Naseer Mohammed Ali, Sawsan Sajid Al-Jubori
Background : Lectin was initially called hemagglutinin or agglutinin because of its capacity to agglutinate human as well as human erythrocytes. They are a heterogeneous group of proteins or glycoproteins of nonimmune origin. Because of their chemical properties, they have become a useful tool in several fields such as immunology, cell biology, molecular biology, membrane structure, pharmacology, cancer research, clinical chemistry, and genetic engineering. Objective : The wide applications of lectins users urged the need to isolate lectins from a new strain of bacteria can produce new and high yield of lectin because the current production of lectin from Pseudomonas spp...
April 4, 2018: Journal of AOAC International
Cornelia Babii, Gabriela Mihalache, Lucian Gabriel Bahrin, Anca-Narcisa Neagu, Irina Gostin, Cosmin Teodor Mihai, Laura-Gabriela Sârbu, Lucian Mihail Birsa, Marius Stefan
The emergence of pathogenic multidrug-resistant bacteria demands new approaches in finding effective antibacterial agents. Synthetic flavonoids could be a reliable solution due to their important antimicrobial activity. We report here the potent in vitro antibacterial activity of ClCl-flav-a novel synthetic tricyclic flavonoid. The antimicrobial effects were tested using the minimum inhibitory concentration (MIC), time kill and biofilm formation assays. Fluorescence microscopy and scanning electron microscopy were employed to study the mechanism of action...
2018: PloS One
Kyulim Lee, JoAnn S Roberts, Chul Hee Choi, Kalina R Atanasova, Özlem Yilmaz
Porphyromonas gingivalis, an opportunistic pathogen usurps gingival epithelial cells (GECs) as primary intracellular niche for its colonization in the oral mucosa. However, the precise characterization of the intracellular trafficking and fate of P. gingivalis in GECs remains incomplete. Therefore, we employed high-resolution three-dimensional-transmission-electron-microscopy to determine the subcellular location of P. gingivalis in human primary GECs upon invasion. Serial sections of infected-GECs and their tomographic reconstruction depicted ER-rich-double-membrane autophagosomal-vacuoles harboring P...
April 4, 2018: Virulence
Majid S Jabir, Ali A Taha, Usama I Sahib
In the present study, antimicrobial activity of Linalool loaded on Glutathione-modified Gold nanoparticles prepared by novel method was investigated. The aim of this study is to evaluate the antimicrobial activity of Linalool-gold nanoparticles (LIN-GNPs) against Gram's positive bacteria Staphylococcus aureus, Gram's negative bacteria Escherichia coli, and against Leishmania tropica. Gold nanoparticles were synthesized using the chemical method. Colour change, UV-Vis spectrum, FTIR and SEM confirmed the characterization of gold nanoparticles and LIN-GNPs...
April 4, 2018: Artificial Cells, Nanomedicine, and Biotechnology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"