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https://www.readbyqxmd.com/read/28811613/transcriptomic-analysis-of-nickel-exposure-in-sphingobium-sp-ba1-cells-using-rna-seq
#1
M Volpicella, C Leoni, C Manzari, M Chiara, E Picardi, E Piancone, F Italiano, A D'Erchia, M Trotta, D S Horner, G Pesole, L R Ceci
Nickel acts as cofactor for a number of enzymes of many bacteria species. Its homeostasis is ensured by proteins working as ion efflux or accumulation systems. These mechanisms are also generally adopted to counteract life-threatening high extra-cellular Ni(2+) concentrations. Little is known regarding nickel tolerance in the genus Sphingobium. We studied the response of the novel Sphingobium sp. ba1 strain, able to adapt to high Ni(2+) concentrations. Differential gene expression in cells cultured in 10 mM Ni(2+), investigated by RNA-seq analysis, identified 118 differentially expressed genes...
August 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28713344/outer-membrane-proteome-of-veillonella-parvula-a-diderm-firmicute-of-the-human-microbiome
#2
Daniel I Poppleton, Magalie Duchateau, Véronique Hourdel, Mariette Matondo, Jennifer Flechsler, Andreas Klingl, Christophe Beloin, Simonetta Gribaldo
Veillonella parvula is a biofilm-forming commensal found in the lungs, vagina, mouth, and gastro-intestinal tract of humans, yet it may develop into an opportunistic pathogen. Furthermore, the presence of Veillonella has been associated with the development of a healthy immune system in infants. Veillonella belongs to the Negativicutes, a diverse clade of bacteria that represent an evolutionary enigma: they phylogenetically belong to Gram-positive (monoderm) Firmicutes yet maintain an outer membrane (OM) with lipopolysaccharide similar to classic Gram-negative (diderm) bacteria...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28698737/draft-genome-sequence-of-a-virulent-strain-of-pasteurella-multocida-isolated-from-alpaca
#3
Raquel Enma Hurtado, Flavia Aburjaile, Diego Mariano, Marcus Vinicius Canário, Leandro Benevides, Daniel Antonio Fernandez, Nataly Olivia Allasi, Rocio Rimac, Julio Eduardo Juscamayta, Jorge Enrique Maximiliano, Raul Hector Rosadio, Vasco Azevedo, Lenin Maturrano
Pasteurella multocida is one of the most frequently isolated bacteria in acute pneumonia cases, being responsible for high mortality rates in Peruvian young alpacas, with consequent social and economic costs. Here we report the genome sequence of P. multocida strain UNMSM, isolated from the lung of an alpaca diagnosed with pneumonia, in Peru. The genome consists of 2,439,814 base pairs assembled into 82 contigs and 2,252 protein encoding genes, revealing the presence of known virulence-associated genes (ompH, ompA, tonB, tbpA, nanA, nanB, nanH, sodA, sodC, plpB and toxA)...
2017: Journal of Genomics
https://www.readbyqxmd.com/read/28667620/assessing-energy-dependent-protein-conformational-changes-in-the-tonb-system
#4
Ray A Larsen
Changes in conformation can alter a protein's vulnerability to proteolysis. Thus, in vivo differential proteinase sensitivity provides a means for identifying conformational changes that mark discrete states in the activity cycle of a protein. The ability to detect a specific conformational state allows for experiments to address specific protein-protein interactions and other physiological components that potentially contribute to the function of the protein. This chapter presents the application of this technique to the TonB-dependent energy transduction system of Gram-negative bacteria, a strategy that has refined our understanding of how the TonB protein is coupled to the ion electrochemical gradient of the cytoplasmic membrane...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28627567/dissecting-binding-of-a-%C3%AE-barrel-membrane-protein-by-phage-display
#5
Luz M Meneghini, Sarvind Tripathi, Marcus A Woodworth, Sudipta Majumdar, Thomas L Poulos, Gregory A Weiss
Membrane proteins (MPs) constitute a third of all proteomes, and contribute to a myriad of cellular functions including intercellular communication, nutrient transport and energy generation. For example, TonB-dependent transporters (TBDTs) in the outer membrane of Gram-negative bacteria play an essential role transporting iron and other nutrients into the bacterial cell. The inherently hydrophobic surfaces of MPs complicates protein expression, purification, and characterization. Thus, dissecting the functional contributions of individual amino acids or structural features through mutagenesis can be a challenging ordeal...
July 25, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28540303/identifying-the-genes-responsible-for-iron-limited-condition-in-riemerella-anatipestifer-ch-1-through-rna-seq-based-analysis
#6
MaFeng Liu, Mi Huang, DeKang Zhu, MingShu Wang, RenYong Jia, Shun Chen, KunFeng Sun, Qiao Yang, Ying Wu, Francis Biville, AnChun Cheng
One of the important elements for most bacterial growth is iron, the bioavailability of which is limited in hosts. Riemerella anatipestifer (R. anatipestifer, RA), an important duck pathogen, requires iron to live. However, the genes involved in iron metabolism and the mechanisms of iron transport are largely unknown. Here, we investigated the transcriptomic effects of iron limitation condition on R. anatipestifer CH-1 using the RNA-Seq and RNA-Seq-based analysis. Data analysis revealed genes encoding functions related to iron homeostasis, including a number of putative TonB-dependent receptor systems, a HmuY-like protein-dependent hemin (an iron-containing porphyrin) uptake system, a Feo system, a gene cluster related to starch utilization, and genes encoding hypothetical proteins that were significantly upregulated in response to iron limitation...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28532667/evaluation-of-three-recombinant-outer-membrane-proteins-ompa1-tdr-and-tbpa-as-potential-vaccine-antigens-against-virulent-aeromonas-hydrophila-infection-in-channel-catfish-ictalurus-punctatus
#7
Hossam Abdelhamed, Iman Ibrahim, Seong Won Nho, Michelle M Banes, Robert W Wills, Attila Karsi, Mark L Lawrence
A virulent clonal population of Aeromonas hydrophila (VAh) is recognized as the etiological agent in outbreaks of motile aeromonas septicemia (MAS) in catfish aquaculture in the southeastern United States since 2009. Genomic subtraction revealed three outer membrane proteins present in VAh strain ML09-119 but not in low virulence reference A. hydrophila strains: major outer membrane protein OmpA1, TonB-dependent receptor (Tdr), and transferrin-binding protein A (TbpA). Here, the genes encoding ompA1, tdr, and tbpA were cloned from A...
May 19, 2017: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/28496441/discovery-of-novel-leptospirosis-vaccine-candidates-using-reverse-and-structural-vaccinology
#8
André Alex Grassmann, Frederico Schmitt Kremer, Júlia Cougo Dos Santos, Jéssica Dias Souza, Luciano da Silva Pinto, Alan John Alexander McBride
Leptospira spp. are diderm (two membranes) bacteria that infect mammals causing leptospirosis, a public health problem with global implications. Thousands of people die every year due to leptospirosis, especially in developing countries with tropical climates. Prophylaxis is difficult due to multiple factors, including the large number of asymptomatic hosts that transmit the bacteria, poor sanitation, increasing numbers of slum dwellers, and the lack of an effective vaccine. Several leptospiral recombinant antigens were evaluated as a replacement for the inactivated (bacterin) vaccine; however, success has been limited...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/28487398/transition-metals-at-the-host-pathogen-interface-how-neisseria-exploit-human-metalloproteins-for-acquiring-iron-and-zinc
#9
REVIEW
Wilma Neumann, Rose C Hadley, Elizabeth M Nolan
Transition metals are essential nutrients for all organisms and important players in the host-microbe interaction. During bacterial infection, a tug-of-war between the host and microbe for nutrient metals occurs: the host innate immune system responds to the pathogen by reducing metal availability and the pathogen tries to outmaneuver this response. The outcome of this competition, which involves metal-sequestering host-defense proteins and microbial metal acquisition machinery, is an important determinant for whether infection occurs...
May 9, 2017: Essays in Biochemistry
https://www.readbyqxmd.com/read/28429713/gating-of-tonb-dependent-transporters-by-substrate-specific-forced-remodelling
#10
Samuel J Hickman, Rachael E M Cooper, Luca Bellucci, Emanuele Paci, David J Brockwell
Membrane proteins play vital roles in inside-out and outside-in signal transduction by responding to inputs that include mechanical stimuli. Mechanical gating may be mediated by the membrane or by protein(s) but evidence for the latter is scarce. Here we use force spectroscopy, protein engineering and bacterial growth assays to investigate the effects of force on complexes formed between TonB and TonB-dependent transporters (TBDT) from Gram-negative bacteria. We confirm the feasibility of protein-only mediated mechanical gating by demonstrating that the interaction between TonB and BtuB (a TBDT) is sufficiently strong under force to create a channel through the TBDT...
April 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28421167/iron-and-virulence-in-francisella-tularensis
#11
REVIEW
Girija Ramakrishnan
Francisella tularensis, the causative agent of tularemia, is a Gram-negative bacterium that infects a variety of cell types including macrophages, and propagates with great efficiency in the cytoplasm. Iron, essential for key enzymatic and redox reactions, is among the nutrients required to support this pathogenic lifestyle and the bacterium relies on specialized mechanisms to acquire iron within the host environment. Two distinct pathways for iron acquisition are encoded by the F. tularensis genome- a siderophore-dependent ferric iron uptake system and a ferrous iron transport system...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28397401/anaerobic-utilization-of-fe-iii-xenosiderophores-among-bacteroides-species-and-the-distinct-assimilation-of-fe-iii-ferrichrome-by-bacteroides-fragilis-within-the-genus
#12
Edson R Rocha, Anna S Krykunivsky
In this study, we show that Bacteroides species utilize Fe(III)-xenosiderophores as the only source of exogenous iron to support growth under iron-limiting conditions in vitro anaerobically. Bacteroides fragilis was the only species able to utilize Fe(III)-ferrichrome while Bacteroides vulgatus ATCC 8482 and Bacteroides thetaiotaomicron VPI 5482 were able to utilize both Fe(III)-enterobactin and Fe(III)-salmochelin S4 as the only source of iron in a dose-dependent manner. We have investigated the way B. fragilis assimilates Fe(III)-ferrichrome as initial model to understand the utilization of xenosiderophores in anaerobes...
August 2017: MicrobiologyOpen
https://www.readbyqxmd.com/read/28352257/a-novel-pan-genome-reverse-vaccinology-approach-employing-a-negative-selection-strategy-for-screening-surface-exposed-antigens-against-leptospirosis
#13
LingBing Zeng, Dongliang Wang, NiYa Hu, Qing Zhu, Kaishen Chen, Ke Dong, Yan Zhang, YuFeng Yao, XiaoKui Guo, Yung-Fu Chang, YongZhang Zhu
Reverse vaccinology (RV) has been widely used for screening of surface-exposed proteins (PSEs) of important pathogens, including outer membrane proteins (OMPs), and extracellular proteins (ECPs) as potential vaccine candidates. In this study, we applied a novel RV negative strategy and a pan-genome analysis for screening of PSEs from 17 L. interrogans strains covering 11 predominately epidemic serovars and 17 multilocus typing (MLST) sequence types (STs) worldwide. Our results showed, for instance, out of a total of 633 predicted PSEs in strain 56601, 92...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28289030/antibiotic-prophylaxis-is-associated-with-subsequent-resistant-infections-in-children-with-an-initial-extended-spectrum-cephalosporin-resistant-enterobacteriaceae-infection
#14
Sibani Das, Amanda L Adler, Arianna Miles-Jay, Matthew P Kronman, Xuan Qin, Scott J Weissman, C A Burnham, Alexis Elward, Jason G Newland, Rangaraj Selvarangan, Kaede V Sullivan, Theoklis Zaoutis, Danielle M Zerr
The objective of this study was to assess the association between previous antibiotic use, particularly long-term prophylaxis, and the occurrence of subsequent resistant infections in children with index infections due to extended-spectrum-cephalosporin-resistant Enterobacteriaceae We also investigated the concordance of the index and subsequent isolates. Extended-spectrum-cephalosporin-resistant Escherichia coli and Klebsiella spp. isolated from normally sterile sites of patients aged <22 years were collected along with associated clinical data from four freestanding pediatric centers...
May 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28276700/iron-acquisition-through-the-bacterial-transferrin-receptor
#15
REVIEW
Anastassia K Pogoutse, Trevor F Moraes
Transferrin is one of the sources of iron that is most readily available to colonizing and invading pathogens. In this review, we look at iron uptake by the bacterial transferrin receptor that is found in the families Neisseriaceae, Pasteurellaceae and Moraxellaceae. This bipartite receptor consists of the TonB-dependent transporter, TbpA, and the surface lipoprotein, TbpB. In the past three decades, major advancements have been made in our understanding of the mechanism through which the Tbps take up iron...
June 2017: Critical Reviews in Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28264993/going-outside-the-tonb-box-identification-of-novel-fepa-tonb-interactions-in-vivo
#16
Michael G Gresock, Kathleen Postle
In Gram-negative bacteria, the cytoplasmic membrane protein TonB transmits energy derived from proton motive force to energize transport of important nutrients through TonB-dependent transporters in the outer membrane. Each transporter consists of a beta barrel domain and a lumen-occluding cork domain containing an essential sequence called the TonB box. To date, the only identified site of transporter-TonB interaction is between the TonB box and residues ∼158 to 162 of TonB. While the mechanism of ligand transport is a mystery, a current model based on site-directed spin labeling and molecular dynamics simulations is that, following ligand binding, the otherwise-sequestered TonB box extends into the periplasm for recognition by TonB, which mediates transport by pulling or twisting the cork...
May 15, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28264906/inactivation-of-nmb0419-encoding-a-sel1-like-repeat-slr-protein-in-neisseria-meningitidis-is-associated-with-differential-expression-of-genes-belonging-to-the-fur-regulon-and-reduced-intraepithelial-replication
#17
Ming-Shi Li, Paul R Langford, J Simon Kroll
Neisseria meningitidis is a commensal microbe that colonizes the human nasopharynx but occasionally invades the bloodstream to cause life-threatening infection. N. meningitidis MC58 NMB0419 encodes a Sel1-like repeat (SLR)-containing protein, previously implicated in invasion of epithelial cells. A gene-regulatory function was revealed in Escherichia coli expressing plasmid-borne NMB0419 and showing significantly increased epithelial adherence compared to the wild type, due to increased expression of mannose-sensitive type 1 pili...
May 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28242720/fluorescence-high-throughput-screening-for-inhibitors-of-tonb-action
#18
Brittany L Nairn, Olivia S Eliasson, Dallas R Hyder, Noah J Long, Aritri Majumdar, Somnath Chakravorty, Peter McDonald, Anuradha Roy, Salete M Newton, Phillip E Klebba
Gram-negative bacteria acquire ferric siderophores through TonB-dependent outer membrane transporters (TBDT). By fluorescence spectroscopic hgh-throughput screening (FLHTS), we identified inhibitors of TonB-dependent ferric enterobactin (FeEnt) uptake through Escherichia coli FepA (EcoFepA). Among 165 inhibitors found in a primary screen of 17,441 compounds, we evaluated 20 in secondary tests: TonB-dependent ferric siderophore uptake and colicin killing and proton motive force-dependent lactose transport. Six of 20 primary hits inhibited TonB-dependent activity in all tests...
May 15, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28242693/manganese-scavenging-and-oxidative-stress-response-mediated-by-type-vi-secretion-system-in-burkholderia-thailandensis
#19
Meiru Si, Chao Zhao, Brianne Burkinshaw, Bing Zhang, Dawei Wei, Yao Wang, Tao G Dong, Xihui Shen
Type VI secretion system (T6SS) is a versatile protein export machinery widely distributed in Gram-negative bacteria. Known to translocate protein substrates to eukaryotic and prokaryotic target cells to cause cellular damage, the T6SS has been primarily recognized as a contact-dependent bacterial weapon for microbe-host and microbial interspecies competition. Here we report contact-independent functions of the T6SS for metal acquisition, bacteria competition, and resistance to oxidative stress. We demonstrate that the T6SS-4 in Burkholderia thailandensis is critical for survival under oxidative stress and is regulated by OxyR, a conserved oxidative stress regulator...
March 14, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28230771/antibiotic-resistance-determinant-focused-acinetobacter-baumannii-vaccine-designed-using-reverse-vaccinology
#20
Zhaohui Ni, Yan Chen, Edison Ong, Yongqun He
As one of the most influential and troublesome human pathogens, Acinetobacter baumannii (A. baumannii) has emerged with many multidrug-resistant strains. After collecting 33 complete A. baumannii genomes and 84 representative antibiotic resistance determinants, we used the Vaxign reverse vaccinology approach to predict classical type vaccine candidates against A. baumannii infections and new type vaccine candidates against antibiotic resistance. Our genome analysis identified 35 outer membrane or extracellular adhesins that are conserved among all 33 genomes, have no human protein homology, and have less than 2 transmembrane helices...
February 21, 2017: International Journal of Molecular Sciences
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