Read by QxMD icon Read

Research in Microbiology

Fernanda Rodrigues-Costa, Rodrigo Cayô, Adriana Pereira Matos, Raquel Girardello, Willames M B S Martins, Floristher Elaine Carrara-Marroni, Ana Cristina Gales
Nine carbapenem-resistant Acinetobacter baumannii isolates carrying blaOXA-231 and an ISAba1 upstream occAB1 were evaluated. They were clonally related and belonged to ST107. An OXA-143-producing A. baumannii ST107 strain (Ac-148) that did not possess ISAba1 upstream occAB1 was included in the analysis. Reduction in the expression of occAB1 and a 4-fold increase of carbapenem MICs were observed for all isolates, except for the Ac-148 strain, probably due to the presence of ISAba1 upstream occAB1 but in the same transcriptional orientation...
July 9, 2018: Research in Microbiology
Catherine Rouzeau, Adilya Dagkesamanskaya, Krzysztof Langer, Jérôme Bibette, Jean Baudry, Denis Pompon, Véronique Anton-Leberre
Adjustment of plasmid copy number resulting from the balance between positive and negative impacts of borne synthetic genes, plays a critical role in the global efficiency of multistep metabolic engineering. Differential expression of co-expressed engineered genes is frequently observed depending on growth phases, metabolic status and triggered adjustments of plasmid copy numbers, constituting a dynamic process contributing to minimize global engineering burden. A yeast model involving plasmid based expression of phosphoribulokinase (PRKp), a key enzyme for the reconstruction of synthetic Calvin cycle, was designed to gain further insights into such a mechanism...
June 28, 2018: Research in Microbiology
Robert Braun, Stefanie Bachmann, Nora Schönberger, Sabine Matys, Franziska Lederer, Katrin Pollmann
Despite many innovations, meeting both economic and ecological requirements remains challenging for conventional resource recovery technology. The development of highly selective peptides puts a new competitor on the market. We present an approach to identify peptides for resource recovery using Phage Surface Display. Here, we describe the development of peptides for binding of rare earth element terbium-containing solids and for removal and enrichment of the heavy metal ions of cobalt and nickel out of waste waters and leaching solutions...
June 18, 2018: Research in Microbiology
Helen F Downie, Joel P Standerwick, Letitia Burgess, Louise S Natrajan, Jonathan R Lloyd
Dissimilatory iron-reducing bacteria (DIRB) play an important role in controlling the redox chemistry of Fe and other transition metals and radionuclides in the environment. During bacterial iron reduction, electrons are transferred from the outer membrane to poorly soluble Fe(III) minerals, although the precise physiological mechanisms and local impact on minerals of these redox processes remain unclear. The aim of this work was to use a range of microscopic techniques to examine the local environment of Geobacter sulfurreducens grown on thin films of Fe(III)-bearing minerals, to provide insight into spatial patterns of Fe(III) reduction and electron transfer...
June 7, 2018: Research in Microbiology
Tamta Tkhilaishvili, Mariagrazia Di Luca, Gerardo Abbandonato, Elena Maryka Maiolo, Ann-Brit Klatt, Monika Reuter, Elisabeth Möncke-Buchner, Andrej Trampuz
Bacterial biofilms, highly resistant to the conventional antimicrobial therapy, remain an unresolved challenge pressing the medical community to investigate new and alternative strategies to fight chronic implant-associated infections. Recently, strictly lytic bacteriophages have been revalued as powerful agents to kill antibiotic-resistant bacteria even in biofilm. Here, the interaction of T3 bacteriophage and planktonic and biofilm Escherichia coli TG1, respectively, was evaluated using isothermal microcalorimetry...
June 7, 2018: Research in Microbiology
Gurinder K Vinner, Danish J Malik
A Salmonella specific bacteriophage Felix O1 (Myoviridae) was microencapsulated in a pH responsive polymer formulation. The formulation incorporated a pH responsive methacrylic acid copolymer Eudragit® S100 (10% (w/v)) with the addition of the biopolymer sodium alginate, the composition of which was varied in the range (0.5% (w/v) - 2% (w/v)). The microencapsulation process employed commercially available microfluidic droplet generation devices. We have used readily available low cost microfluidic chips instead of bespoke in-house fabricated glass capillary devices which are accessible only in specialist research facilities...
June 7, 2018: Research in Microbiology
Adriana B Cesari, Natalia S Paulucci, María A Biasutti, Gustavo M Morales, Marta S Dardanelli
We evaluate the behavior of the membrane of Bradyrhizobium sp. SEMIA6144 during adaptation to polyethylene glycol (PEG). A dehydrating effect on the morphology of the cell surface, as well as a fluidizing effect on the membrane was observed 10 min after PEG shock; however, the bacteria were able to restore optimal membrane fluidity. Shock for 1 h caused an increase of lysophosphatidylethanolamine in the outer membrane at the expense of phosphatidylcholine and phosphatidylethanolamine (PE), through an increase in phospholipase activity...
June 2, 2018: Research in Microbiology
Sophie R Ullrich, Anja Poehlein, Gloria Levicán, Martin Mühling, Michael Schlömann
The response of the acidophilic iron oxidizer "Ferrovum" sp. JA12 to elevated concentrations of ferrous iron was targeted at transcriptome level in order to assess models on oxidative stress management and ferrous iron oxidation. Overall transcriptome profiles indicate a high cellular activity of "Ferrovum" sp. JA12 up to 50 mM of ferrous iron with genes predicted to be involved in iron oxidation, carbon fixation and ribosome formation showing the highest transcript levels. The data support the iron oxidation pathway inferred from genome analysis and draws attention to further redox proteins potentially associated with iron oxidation...
June 2, 2018: Research in Microbiology
Carolina E Cabezas, Alan C Briones, Camila Aguirre, Coral Pardo-Esté, Juan Castro-Severyn, César R Salinas, María S Baquedano, Alejandro A Hidalgo, Juan A Fuentes, Eduardo H Morales, Claudio A Meneses, Eduardo Castro-Nallar, Claudia Paz Saavedra
Salmonella Typhimurium is an intracellular pathogen that is capable of generating systemic fever in a murine model. Over the course of the infection, Salmonella faces different kinds of stressors, including harmful reactive oxygen species (ROS). Various defence mechanisms enable Salmonella to successfully complete the infective process in the presence of such stressors. The transcriptional factor SlyA is involved in the oxidative stress response and invasion of murine macrophages. We evaluated the role of SlyA in response to H2 O2 and NaOCl and found an increase of slyA expression upon exposure to these toxics...
May 29, 2018: Research in Microbiology
Melissa K Corbett, Jacques J Eksteen, Xi-Zhi Niu, Elizabeth L J Watkin
The unique physiochemical properties exhibited by rare earth elements (REEs) and their increasing application in high-tech industries has created a demand for secure supply lines with established recovery procedures that create minimal environmental damage. Bioleaching experiments conducted on a non-sterile monazite concentrate with a known phosphate solubilising microorganism (PSM) resulted in greater mobilisation of REEs into solution in comparison to experiments conducted on sterile monazite. By combining the native consortia with an introduced PSM, a syntrophic effect between the populations effectively leached a greater amount of REEs than either a single PSM or the indigenous population alone...
May 28, 2018: Research in Microbiology
Gabriel Mf Almeida, Miika Leppänen, Ilari J Maasilta, Lotta-Riina Sundberg
The visualization of viral particles only became possible after the advent of the electron microscope. The first bacteriophage images were published in 1940 and were soon followed by many other publications that helped to elucidate the structure of the particles and their interaction with the bacterial hosts. As sample preparation improved and new technologies were developed, phage imaging became important approach to morphologically classify these viruses and helped to understand its importance in the biosphere...
May 28, 2018: Research in Microbiology
Martijn Zwama, Akihito Yamaguchi
The over-expression of multidrug efflux pumps belonging to the Resistance-Nodulation-Division (RND) superfamily is one of the main causes of multidrug-resistance (MDR) in Gram-negative pathogenic bacteria. AcrB is the most thoroughly studied RND transporter and has functioned as a model for our understanding of efflux-mediated MDR. This multidrug-exporter can recognize and transport a wide range of structurally unrelated compounds (including antibiotics, dyes, bile salts and detergents), while it shows a strict inhibitor specificity...
May 25, 2018: Research in Microbiology
Alma Laura Díaz-Pérez, Cinthia Núñez, Victor Meza Carmen, Jesús Campos-García
Pseudomonas aeruginosa metabolizes leucine through the leucine/isovalerate utilization pathway, whose enzymes are encoded in the liuRABCDE gene cluster (liu). In this study, we investigated the role of the LiuR protein in the liu cluster regulation. Our results indicated that liu expression is regulated at the transcriptional level by LiuR. Mobility shift assays using purified recombinant His-tagged LiuR showed that it was able to bind at the promoter region of liuR, in a dose-dependent manner. Results revealed that expression of the liu operon is subjected to carbon catabolite repression control (CCR); protein LiuD was strongly expressed in the presence of leucine, but it was repressed in the presence of glucose or succinate...
May 19, 2018: Research in Microbiology
Arthur Neuberger, Dijun Du, Ben F Luisi
Efflux pumps are membrane proteins which contribute to multi-drug resistance. In Gram-negative bacteria, some of these pumps form complex tripartite assemblies in association with an outer membrane channel and a periplasmic membrane fusion protein. These tripartite machineries span both membranes and the periplasmic space, and they extrude from the bacterium chemically diverse toxic substrates. In this chapter, we summarise current understanding of the structural architecture, functionality, and regulation of tripartite multi-drug efflux assemblies...
May 19, 2018: Research in Microbiology
Colin Buttimer, Yannick Born, Alan Lucid, Martin J Loessner, Lars Fieseler, Aidan Coffey
To date, a small number of jumbo myoviruses have been reported to possess atypical whisker-like structures along the surface of their contractile tails. Erwinia amylovora phage vB_EamM_Y3 is another example. It possesses a genome of 261,365 kbp with 333 predicted ORFs. Using a combination of BLASTP, Interproscan and HHpred, about 21% of its putative proteins could be assigned functions involved in nucleotide metabolism, DNA replication, virion structure and cell wall degradation. The phage was found to have a signal-arrest-release (SAR) endolysin (Y3_301) possessing a soluble lytic transglycosylase domain...
May 18, 2018: Research in Microbiology
Andrew M Kropinski
Research on bacteriophages has significantly enhanced our understanding of molecular biology, the genomes of prokaryotic cells, and viral ecology. Phages and lysins offer a viable alternative to the declining utility of antibiotics in this post-antibiotic era. They also provide ideal teaching tools for genomics and bioinformatics. This article touches on the first 100 years of phage research with the author commenting on what he thinks are the highlights, and what needs to be addressed.
May 16, 2018: Research in Microbiology
N Hoyle, P Zhvaniya, N Balarjishvili, D Bolkvadze, L Nadareishvili, D Nizharadze, J Wittmann, C Rohde, M Kutateladze
Respiratory infections can lead to serious complications in CF patients, especially when infected with antibiotic resistant bacteria. Alternative treatments for these infections are being sought out to help address this problem. We present a clinical case of a cystic fibrosis (CF) patient, with multi-drug resistant (MDR) Achromobacter xylosoxidans chronic lung infection who was successfully managed with bacteriophage therapy.
May 16, 2018: Research in Microbiology
Daniel Gelman, Shaul Beyth, Vanda Lerer, Karen Adler, Ronit Poradosu-Cohen, Shunit Coppenhagen-Glazer, Ronen Hazan
Clinical applications of bacteriophage therapy have been recently gathering significant attention worldwide, used mostly as rescue therapy in cases of near-fatal antibiotic failure. Thus, clinically relevant in-vivo models presenting both short- and long-term implications of phage therapy given as rescue treatment for fulminant infections are of highest importance. In this study, a cocktail consisting of two lytic bacteriophages was used to evaluate the therapeutic efficacy of phage therapy as a rescue treatment for severe septic peritonitis in a mouse model...
May 16, 2018: Research in Microbiology
Nina S Atanasova, Tatiana A Demina, Sudar N V Krishnam Rajan Shanthi, Hanna M Oksanen, Dennis H Bamford
Certain pleomorphic archaeal viruses are highly infectious even at saturated salt. These viruses belong to the genus Betapleolipovirus of the recently described archaeal virus family Pleolipoviridae. Pleolipoviruses comprise single-stranded or double-stranded, circular or linear DNA genomes that share countless homologues among various archaeal genetic elements. Here we describe a new extremely halophilic betapleolipovirus, Halorubrum pleomorphic virus 9 (HRPV9), which has an integrase gene. We also identified new genes encoding minor pleolipoviral structural proteins...
May 14, 2018: Research in Microbiology
Lea Wittorf, Christopher M Jones, Germán Bonilla-Rosso, Sara Hallin
Reduction of nitrite to nitric oxide in denitrification is catalysed by two different nitrite reductases, encoded by nirS or nirK. Long considered mutually exclusive and functionally redundant in denitrifying bacteria, we show expression of both genes co-occurring in Pseudomonas stutzeri. The differential expression patterns between strain AN10 and JM300 in relation to oxygen and nitrate and their different denitrification phenotypes, with AN10 reducing nitrate more rapidly and accumulating nitrite, suggest that nirS and nirK can have different roles...
May 9, 2018: Research in Microbiology
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"