Read by QxMD icon Read

Bacteria secretion system

Cullen L Myers, Franco K K Li, Byoung-Mo Koo, Omar M El-Halfawy, Shawn French, Carol A Gross, Natalie C J Strynadka, Eric D Brown
The cell wall of most Gram-positive bacteria contains equal amounts of peptidoglycan and the phosphate-rich glycopolymer wall teichoic acid (WTA). During phosphate-limited growth of the Gram-positive model organism Bacillus subtilis 168, WTA is lost from the cell wall in a response mediated by the PhoPR two component system, which regulates genes involved in phosphate conservation and acquisition. It has been thought that WTA provides a phosphate source to sustain growth during starvation conditions, however, WTA degradative pathways have not been described for this, or any condition of bacterial growth...
October 25, 2016: Journal of Biological Chemistry
Yuji Nadatani, Xiaofang Huo, Xi Zhang, Chunhua Yu, Edaire Cheng, Qiuyang Zhang, Kerry B Dunbar, Arianne Theiss, Thai H Pham, David H Wang, Toshio Watanabe, Yasuhiro Fujiwara, Tetsuo Arakawa, Stuart J Spechler, Rhonda F Souza
BACKGROUND & AIMS: Microbial molecular products incite intestinal inflammation by activating Toll-like receptors (TLRs) and inflammasomes of the innate immune system. This system's contribution to esophageal inflammation is not known. Gram-negative bacteria, which dominate the esophageal microbiome in reflux esophagitis, produce lipopolysaccharide (LPS), a TLR4 ligand. TLR4 signaling produces pro-interleukin (IL)1β, pro-IL18, and NOD-like receptor protein 3 (NLRP3), which prime the NLRP3 inflammasome...
July 2016: Cellular and Molecular Gastroenterology and Hepatology
Vera Pader, Sanika Hakim, Kimberley L Painter, Sivaramesh Wigneshweraraj, Thomas B Clarke, Andrew M Edwards
Daptomycin is a bactericidal antibiotic of last resort for serious infections caused by methicillin-resistant Staphylococcus aureus (MRSA)(1,2). Although resistance is rare, treatment failure can occur in more than 20% of cases(3,4) and so there is a pressing need to identify and mitigate factors that contribute to poor therapeutic outcomes. Here, we show that loss of the Agr quorum-sensing system, which frequently occurs in clinical isolates, enhances S. aureus survival during daptomycin treatment. Wild-type S...
October 24, 2016: Nature Microbiology
Kuo-Hsun Chiu, Ling-Hui Wang, Tsung-Ting Tsai, Huan-Yao Lei, Pao-Chi Liao
The secreted proteins of bacteria are usually accompanied by virulence factors, which can cause inflammation and damage host cells. Identifying the secretomes arising from the interactions of bacteria and host cells could, therefore, increase understanding of the mechanisms during initial pathogenesis. The present study used a host-pathogen coculture system of Helicobacter pylori and monocytes (THP-1 cells) to investigate the secreted proteins associated with initial H. pylori pathogenesis. The secreted proteins from the conditioned media from H...
October 20, 2016: Journal of Proteome Research
H Y Shi, Q D Li, X Y Wan
Objective: To investigate the destructive effects of erythromycin on biofilm of MRSA and find the effect of erythromycin on QS related factors. Methods: Tested the MBC of erythromycin on MRSA.Established the model of biofilm.Erythromycin was added into the medium when bacteria were inoculated for 24 h. Tested the biofilm and collected the supernatant or serum of rat at 6, 12, 24, 48, 72 h and 7 d after adding erythromycin to detect the concentration of autoinducing peptides (AIP). Results: The MBC of the erythromycin on standard strains of MRSA was 256 g/L...
October 11, 2016: Zhonghua Yi Xue za Zhi [Chinese medical journal]
Young Ha Ahn, Sunyoung Park, Jeong June Choi, Bo-Kyung Park, Kyung Hee Rhee, Eunjoo Kang, Soyeon Ahn, Chul-Ho Lee, Jong Soo Lee, Kyung-Soo Inn, Mi-La Cho, Sung-Hwan Park, Kyunghee Park, Hae Jung Park, Jae Hyun Lee, Jung Won Park, Nam Hoon Kwon, Hyunbo Shim, Byung Woo Han, Pilhan Kim, Joo-Youn Lee, Youngho Jeon, Jin Won Huh, Mirim Jin, Sunghoon Kim
The N-terminal truncated form of a protein synthesis enzyme, tryptophanyl-tRNA synthetase (mini-WRS), is secreted as an angiostatic ligand. However, the secretion and function of the full-length WRS (FL-WRS) remain unknown. Here, we report that the FL-WRS, but not mini-WRS, is rapidly secreted upon pathogen infection to prime innate immunity. Blood levels of FL-WRS were increased in sepsis patients, but not in those with sterile inflammation. FL-WRS was secreted from monocytes and directly bound to macrophages via a toll-like receptor 4 (TLR4)-myeloid differentiation factor 2 (MD2) complex to induce phagocytosis and chemokine production...
October 17, 2016: Nature Microbiology
Kerrie L May, Thomas J Silhavy
The outer membrane (OM) of Gram-negative bacteria is positioned at the frontline of the cell's interaction with its environment and provides a barrier against influx of external toxins while still allowing import of nutrients and excretion of wastes. It is a remarkable asymmetric bilayer with a glycolipid surface-exposed leaflet and a glycerophospholipid inner leaflet. Lipid asymmetry is key to OM barrier function and several different systems actively maintain this lipid asymmetry. All OM components are synthesized in the cytosol before being secreted and assembled into a contiguous membrane on the other side of the cell wall...
October 11, 2016: Biochimica et Biophysica Acta
Catherine Daniel, Marie Titecat, Sabine Poiret, Delphine Cayet, Denise Boutillier, Michel Simonet, Jean-Claude Sirard, Nadine Lemaître, Florent Sebbane
BACKGROUND: Pseudotuberculosis is an infection caused by the bacterial enteropathogen Yersinia pseudotuberculosis and is considered to be a significant problem in veterinary medicine. We previously found that intranasal administration of a recombinant Lactococcus lactis strain that secretes the low-calcium response V (LcrV) antigen from Y. pseudotuberculosis (Ll-LcrV) confers protection against a lethal Y. pseudotuberculosis infection. Here, we aimed at characterizing the immunological basis of this LcrV-elicited protective response and at determining the duration of vaccine-induced immunity...
October 11, 2016: Vaccine
Na Han, Weiwen Yu, Yujun Qiang, Wen Zhang
Type IV secretion system (T4SS) can mediate the passage of macromolecules across cellular membranes and is essential for virulent and genetic material exchange among bacterial species. The Type IV Secretion Project 2.0 (T4SP 2.0) database is an improved and extended version of the platform released in 2013 aimed at assisting with the detection of Type IV secretion systems (T4SS) in bacterial genomes. This advanced version provides users with web server tools for detecting the existence and variations of T4SS genes online...
2016: Computational and Mathematical Methods in Medicine
Qiang Zheng, Yanting Liu, Christian Jeanthon, Rui Zhang, Wenxin Lin, Jicheng Yao, Nianzhi Jiao
: Aerobic anoxygenic phototrophic bacteria (AAPB) are thought to be important players in oceanic carbon and energy cycling in the euphotic zone of the ocean. The genus Citromicrobium, widely found in oligotrophic oceans, is a member of marine alphaproteobacterial AAPB. Nine Citromicrobium strains isolated from the South China Sea, the Mediterranean Sea or the tropical South Atlantic were found to harbor identical 16S rRNA sequences. The sequencing of their genomes revealed high synteny in major regions...
October 7, 2016: Applied and Environmental Microbiology
Peter J Christie
Escherichia coli and other Gram-negative and -positive bacteria employ type IV secretion systems (T4SSs) to translocate DNA and protein substrates, generally by contact-dependent mechanisms, to other cells. The T4SSs functionally encompass two major subfamilies, the conjugation systems and the effector translocators. The conjugation systems are responsible for interbacterial transfer of antibiotic resistance genes, virulence determinants, and genes encoding other traits of potential benefit to the bacterial host...
October 2016: EcoSal Plus
Guopeng Wei, Chieh Lo, Connor Walsh, N Luisa Hiller, Radu Marculescu
As understanding of bacterial regulatory systems and pathogenesis continues to increase, QSI has been a major focus of research. However, recent studies have shown that mechanisms of resistance to quorum sensing (QS) inhibitors (QSIs) exist, calling into question their clinical value. We propose a computational framework that considers bacteria genotypes relative to QS genes and QS-regulated products including private, quasi-public, and public goods according to their impacts on bacterial fitness. Our results show (1) QSI resistance spreads when QS positively regulates the expression of private or quasi-public goods...
October 13, 2016: Scientific Reports
Brent S Weber, Seth W Hennon, Meredith S Wright, Nichollas E Scott, Véronique de Berardinis, Leonard J Foster, Juan A Ayala, Mark D Adams, Mario F Feldman
: The type VI secretion system (T6SS) is a widespread secretory apparatus produced by Gram-negative bacteria that has emerged as a potent mediator of antibacterial activity during interbacterial interactions. Most Acinetobacter species produce a genetically conserved T6SS, although the expression and functionality of this system vary among different strains. Some pathogenic Acinetobacter baumannii strains activate this secretion system via the spontaneous loss of a plasmid carrying T6SS repressors...
October 11, 2016: MBio
Florian Hoss, Christina F Budden, Eicke Latz
When bacteria infect a cell, the bacterial membrane partially shields microbial structures from the immune system, preventing detection and clearance. In a recent issue of Cell, Man et al. (2016) show that the interferon-inducible protein IRGB10 liberates bacterial ligands for sensing by both the AIM2 and the non-canonical NLRP3 inflammasomes.
October 10, 2016: Developmental Cell
Sanna Koskiniemi, Johan Elf
Bacteria use type 6 secretion systems in antagonistic behavior to compete for resources with other bacteria. In a recent issue of Cell, Vettiger and Basler (2016) show that bacteria can also use these systems to arm neighboring cells and force them to pass on a signal in the bacterial population.
October 10, 2016: Developmental Cell
Habiba Ennouri, Paul d'Abzac, Florence Hakil, Priscilla Branchu, Murielle Naïtali, Anne-Marie Lomenech, Rhida Oueslati, Jacques Desbrières, Pierre Sivadon, Régis Grimaud
The assimilation of the nearly water insoluble substrates hydrocarbons and lipids by bacteria entails specific adaptations such as the formation of oleolytic biofilms. The present article reports that the extracellular matrix of an oleolytic biofilm formed by Marinobacter hydrocarbonoclasticus at n-hexadecane-water interfaces is largely composed of proteins typically cytoplasmic such as translation factors and chaperones, and a lesser amount of proteins of unknown function that are predicted extra-cytoplasmic...
October 11, 2016: Environmental Microbiology
Walter J Lukiw
The human microbiome consists of ~3.8 × 10(13) symbiotic microorganisms that form a highly complex and dynamic ecosystem: the gastrointestinal (GI) tract constitutes the largest repository of the human microbiome by far, and its impact on human neurological health and disease is becoming increasingly appreciated. Bacteroidetes, the largest phylum of Gram-negative bacteria in the GI tract microbiome, while generally beneficial to the host when confined to the GI tract, have potential to secrete a remarkably complex array of pro-inflammatory neurotoxins that include surface lipopolysaccharides (LPSs) and toxic proteolytic peptides...
2016: Frontiers in Microbiology
Zhenping Cao, M Guillermina Casabona, Holger Kneuper, James D Chalmers, Tracy Palmer
The type VII protein secretion system (T7SS) plays a critical role in the virulence of human pathogens including Mycobacterium tuberculosis and Staphylococcus aureus. Here, we report that the S. aureus T7SS secretes a large nuclease toxin, EsaD. The toxic activity of EsaD is neutralized during its biosynthesis through complex formation with an antitoxin, EsaG, which binds to its C-terminal nuclease domain. The secretion of EsaD is dependent on a further accessory protein, EsaE, that does not interact with the nuclease domain, but instead binds to the EsaD N-terminal region...
October 10, 2016: Nature Microbiology
Mohammad F Mehbub, Jason E Tanner, Stephen J Barnett, Christopher M M Franco, Wei Zhang
Sponge-associated bacteria play a critical role in sponge biology, metabolism and ecology, but how they interact with their host sponges and the role of these interactions are poorly understood. This study investigated the role of the interaction between the sponge Aplysilla rosea and its associated actinobacterium, Streptomyces ACT-52A, in modifying sponge microbial diversity, metabolite profile and bioactivity. A recently developed experimental approach that exposes sponges to bacteria of interest in a controlled aquarium system was improved by including the capture and analysis of secreted metabolites by the addition of an absorbent resin in the seawater...
October 7, 2016: Applied Microbiology and Biotechnology
Libera Lo Presti, Bernd Zechmann, Jochen Kumlehn, Liang Liang, Daniel Lanver, Shigeyuki Tanaka, Ralph Bock, Regine Kahmann
Successful colonization of plants by prokaryotic and eukaryotic pathogens requires active effector-mediated suppression of defense responses and host tissue reprogramming. Secreted effector proteins can either display their activity in the apoplast or translocate into host cells and function therein. Although characterized in bacteria, the molecular mechanisms of effector delivery by fungal phytopathogens remain elusive. Here we report the establishment of an assay that is based on biotinylation of effectors in the host cytoplasm as hallmark of uptake...
September 26, 2016: New Phytologist
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"