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Bacteria evolution

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https://www.readbyqxmd.com/read/27933456/penicillin-v-acylases-from-gram-negative-bacteria-degrade-n-acylhomoserine-lactones-and-attenuate-virulence-in-pseudomonas-aeruginosa
#1
Avinash Vellore Sunder, Putri Dwi Utari, Sureshkumar Ramasamy, Ronald van Merkerk, Wim Quax, Archana Pundle
Virulence pathways in gram-negative pathogenic bacteria are regulated by quorum sensing mechanisms, through the production and sensing of N-acylhomoserine lactone (AHL) signal molecules. Enzymatic degradation of AHLs leading to attenuation of virulence (quorum quenching) could pave the way for the development of new antibacterials. Penicillin V acylases (PVAs) belong to the Ntn hydrolase superfamily, together with AHL acylases. PVAs are exploited widely in the pharmaceutical industry, but their role in the natural physiology of their native microbes is not clearly understood...
December 8, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27933056/characterization-of-three-novel-sxt-r391-integrating-conjugative-elements-icemfuind1a-and-icemfuind1b-and-icemprchn1-identified-in-the-genomes-of-marinomonas-fungiae-jcm-18476-t-and-marinomonas-profundimaris-strain-d104
#2
Jhasketan Badhai, Subrata K Das
The genus Marinomonas comprises Gram negative bacteria which are widespread in the marine environment and there is no report on the genomic analysis of SXT/R391 ICEs derived from this group of bacteria. This study describes the genomic features of three new SXT/R391 integrating conjugating elements (ICEs) identified in the genome of Marinomonas fungiae JCM 18476(T) (ICEMfuInd1a and ICEMfuInd1b) and in Marinomonas profundimaris strain D104 (ICEMprChn1). Structural organizations of the three ICEs were similar to the typical SXT/R391 family of ICEs and showed high degree of conservation in the core genes...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27930295/birth-of-a-w-sex-chromosome-by-horizontal-transfer-of-wolbachia-bacterial-symbiont-genome
#3
Sébastien Leclercq, Julien Thézé, Mohamed Amine Chebbi, Isabelle Giraud, Bouziane Moumen, Lise Ernenwein, Pierre Grève, Clément Gilbert, Richard Cordaux
Sex determination is a fundamental developmental pathway governing male and female differentiation, with profound implications for morphology, reproductive strategies, and behavior. In animals, sex differences between males and females are generally determined by genetic factors carried by sex chromosomes. Sex chromosomes are remarkably variable in origin and can differ even between closely related species, indicating that transitions occur frequently and independently in different groups of organisms. The evolutionary causes underlying sex chromosome turnover are poorly understood, however...
December 6, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27929718/lotus-japonicus-nf-ya1-plays-an-essential-role-during-nodule-differentiation-and-targets-members-of-the-shi-sty-gene-family
#4
Md Shakhawat Hossain, Arina Shrestha, Sihui Zhong, Mandana Miri, Ryan S Austin, Shusei Sato, Loretta Ross, Terry Huebert, Alexandre Tromas, Ivone Torres-Jerez, Yuhong Tang, Michael Udvardi, Jeremy Dale Murray, Krzysztof Szczyglowski
Legume plants engage in intimate relationships with rhizobial bacteria to form nitrogen-fixing nodules, root-derived organs that accommodate the micro-symbiont. Members of the Nuclear Factor Y (NF-Y) gene family, which have undergone significant expansion and functional diversification during plant evolution, are essential for this symbiotic liaison. Acting in a partially redundant manner, NF-Ys were shown previously to regulate bacterial infection, including selection of a superior rhizobial strain, and to mediate nodule structure formation...
December 8, 2016: Molecular Plant-microbe Interactions: MPMI
https://www.readbyqxmd.com/read/27927177/initiator-trna-genes-template-the-3-cca-end-at-high-frequencies-in-bacteria
#5
David H Ardell, Ya-Ming Hou
BACKGROUND: While the CCA sequence at the mature 3' end of tRNAs is conserved and critical for translational function, a genetic template for this sequence is not always contained in tRNA genes. In eukaryotes and Archaea, the CCA ends of tRNAs are synthesized post-transcriptionally by CCA-adding enzymes. In Bacteria, tRNA genes template CCA sporadically. RESULTS: In order to understand the variation in how prokaryotic tRNA genes template CCA, we re-annotated tRNA genes in tRNAdb-CE database version 0...
December 8, 2016: BMC Genomics
https://www.readbyqxmd.com/read/27925169/parasites-and-competitors-suppress-bacterial-pathogen-synergistically-due-to-evolutionary-trade-offs
#6
Xiaofang Wang, Zhong Wei, Mei Li, Xueqi Wang, Anqi Shan, Xinlan Mei, Alexandre Jousset, Qirong Shen, Yangchun Xu, Ville-Petri Friman
Parasites and competitors are important for regulating pathogen densities and subsequent disease dynamics. It is, however, unclear to what extent this is driven by ecological and evolutionary processes. Here we used experimental evolution to study the eco-evolutionary feedbacks between Ralstonia solanacearum bacterial pathogen, Ralstonia-specific phage parasite and Bacillus amyloliquefaciens competitor bacterium in the laboratory and plant rhizosphere. We found that while the phage had a small effect on pathogen densities on its own, it considerably increased the R...
December 7, 2016: Evolution; International Journal of Organic Evolution
https://www.readbyqxmd.com/read/27924829/diverse-specificity-of-cellulosome-attachment-to-the-bacterial-cell-surface
#7
Joana L A Brás, Benedita A Pinheiro, Kate Cameron, Fiona Cuskin, Aldino Viegas, Shabir Najmudin, Pedro Bule, Virginia M R Pires, Maria João Romão, Edward A Bayer, Holly L Spencer, Steven Smith, Harry J Gilbert, Victor D Alves, Ana Luísa Carvalho, Carlos M G A Fontes
During the course of evolution, the cellulosome, one of Nature's most intricate multi-enzyme complexes, has been continuously fine-tuned to efficiently deconstruct recalcitrant carbohydrates. To facilitate the uptake of released sugars, anaerobic bacteria use highly ordered protein-protein interactions to recruit these nanomachines to the cell surface. Dockerin modules located within a non-catalytic macromolecular scaffold, whose primary role is to assemble cellulosomal enzymatic subunits, bind cohesin modules of cell envelope proteins, thereby anchoring the cellulosome onto the bacterial cell...
December 7, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27924410/does-antibiotic-resistance-evolve-in-hospitals
#8
Anna Seigal, Portia Mira, Bernd Sturmfels, Miriam Barlow
Nosocomial outbreaks of bacteria are well documented. Based on these incidents, and the heavy usage of antibiotics in hospitals, it has been assumed that antibiotic resistance evolves in hospital environments. To test this assumption, we studied resistance phenotypes of bacteria collected from patient isolates at a community hospital over a 2.5-year period. A graphical model analysis shows no association between resistance and patient information other than time of arrival. This allows us to focus on time-course data...
December 6, 2016: Bulletin of Mathematical Biology
https://www.readbyqxmd.com/read/27923922/mechanisms-of-evolution-in-high-consequence-drug-resistance-plasmids
#9
Susu He, Michael Chandler, Alessandro M Varani, Alison B Hickman, John P Dekker, Fred Dyda
: The dissemination of resistance among bacteria has been facilitated by the fact that resistance genes are usually located on a diverse and evolving set of transmissible plasmids. However, the mechanisms generating diversity and enabling adaptation within highly successful resistance plasmids have remained obscure, despite their profound clinical significance. To understand these mechanisms, we have performed a detailed analysis of the mobilome (the entire mobile genetic element content) of a set of previously sequenced carbapenemase-producing Enterobacteriaceae (CPE) from the National Institutes of Health Clinical Center...
December 6, 2016: MBio
https://www.readbyqxmd.com/read/27922601/the-effect-of-extrinsic-mortality-on-genome-size-evolution-in-prokaryotes
#10
Piotr Bentkowski, Cock van Oosterhout, Ben Ashby, Thomas Mock
Mortality has a significant role in prokaryotic ecology and evolution, yet the impact of variations in extrinsic mortality on prokaryotic genome evolution has received little attention. We used both mathematical and agent-based models to reveal how variations in extrinsic mortality affect prokaryotic genome evolution. Our results suggest that the genome size of bacteria increases with increased mortality. A high extrinsic mortality increases the pool of free resources and shortens life expectancy, which selects for faster reproduction, a phenotype we called 'scramblers'...
December 6, 2016: ISME Journal
https://www.readbyqxmd.com/read/27922269/genomic-study-of-the-type-ivc-secretion-system-in-clostridium-difficile-understanding-c-difficile-evolution-via-horizontal-gene-transfer
#11
Wen Zhang, Ying Cheng, Pengcheng Du, Yuanyuan Zhang, Hongbing Jia, Xianping Li, Jing Wang, Na Han, Yujun Qiang, Chen Chen, Jinxing Lu
Clostridium difficile, the etiological agent of Clostridium difficile infection (CDI), is a gram-positive, spore-forming bacillus that is responsible for ∼20% of antibiotic-related cases of diarrhea and nearly all cases of pseudomembranous colitis. Previous data have shown that a substantial proportion (11%) of the C. difficile genome consists of mobile genetic elements, including seven conjugative transposons. However, the mechanism underlying the formation of a mosaic genome in C. difficile is unknown. The type-IV secretion system (T4SS) is the only secretion system known to transfer DNA segments among bacteria...
August 30, 2016: Genome Génome / Conseil National de Recherches Canada
https://www.readbyqxmd.com/read/27920385/sublethal-streptomycin-concentrations-and-lytic-bacteriophage-together-promote-resistance-evolution
#12
Johannes Cairns, Lutz Becks, Matti Jalasvuori, Teppo Hiltunen
Sub-minimum inhibiting concentrations (sub-MICs) of antibiotics frequently occur in natural environments owing to wide-spread antibiotic leakage by human action. Even though the concentrations are very low, these sub-MICs have recently been shown to alter bacterial populations by selecting for antibiotic resistance and increasing the rate of adaptive evolution. However, studies are lacking on how these effects reverberate into key ecological interactions, such as bacteria-phage interactions. Previously, co-selection of bacteria by phages and antibiotic concentrations exceeding MICs has been hypothesized to decrease the rate of resistance evolution because of fitness costs associated with resistance mutations...
January 19, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/27920384/antibiotic-resistance-in-the-wild-an-eco-evolutionary-perspective
#13
REVIEW
Teppo Hiltunen, Marko Virta, Anna-Liisa Laine
The legacy of the use and misuse of antibiotics in recent decades has left us with a global public health crisis: antibiotic-resistant bacteria are on the rise, making it harder to treat infections. At the same time, evolution of antibiotic resistance is probably the best-documented case of contemporary evolution. To date, research on antibiotic resistance has largely ignored the complexity of interactions that bacteria engage in. However, in natural populations, bacteria interact with other species; for example, competition and grazing are import interactions influencing bacterial population dynamics...
January 19, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/27919802/integrative-view-of-2-oxoglutarate-fe-ii-dependent-oxygenase-diversity-and-functions-in-bacteria
#14
Baolei Jia, Xiaomeng Jia, Kyung Hyun Kim, Che Ok Jeon
BACKGROUND: The 2-oxoglutarate/Fe(II)-dependent oxygenase (2OG oxygenase) superfamily is extremely diverse and includes enzymes responsible for protein modification, DNA and mRNA repair, and synthesis of secondary metabolites. METHODS: To investigate the evolutionary relationship and make functional inferences within this remarkably diverse superfamily in bacteria, we used a protein sequence similarity network and other bioinformatics tools to analyze the bacterial proteins in the superfamily...
December 2, 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27917155/aerobic-lineage-of-the-oxidative-stress-response-protein-rubrerythrin-emerged-in-an-ancient-microaerobic-hyper-thermophilic-environment
#15
Juan P Cardenas, Raquel Quatrini, David S Holmes
Rubrerythrins (RBRs) are non-heme di-iron proteins belonging to the ferritin-like superfamily. They are involved in oxidative stress defense as peroxide scavengers in a wide range of organisms. The vast majority of RBRs, including classical forms of this protein, contain a C-terminal rubredoxin-like domain involved in electron transport that is used during catalysis in anaerobic conditions. Rubredoxin is an ancient and large protein family of short length (<100 residues) that contains a Fe-S center involved in electron transfer...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27914076/reconstructing-the-ancestral-relationships-between-bacterial-pathogen-genomes
#16
Caitlin Collins, Xavier Didelot
Following recent developments in DNA sequencing technology, it is now possible to sequence hundreds of whole genomes from bacterial isolates at relatively low cost. Analyzing this growing wealth of genomic data in terms of ancestral relationships can reveal many interesting aspects of the evolution, ecology, and epidemiology of bacterial pathogens. However, reconstructing the ancestry of a sample of bacteria remains challenging, especially for the majority of species where recombination is frequent. Here, we review and describe the computational techniques currently available to infer ancestral relationships, including phylogenetic methods that either ignore or account for the effect of recombination, as well as model-based and model-free phylogeny-independent approaches...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/27913665/structure-and-function-of-bacterial-h-ns-protein
#17
REVIEW
David C Grainger
The histone-like nucleoid structuring (H-NS) protein is a major component of the folded chromosome in Escherichia coli and related bacteria. Functions attributed to H-NS include management of genome evolution, DNA condensation, and transcription. The wide-ranging influence of H-NS is remarkable given the simplicity of the protein, a small peptide, possessing rudimentary determinants for self-association, hetero-oligomerisation and DNA binding. In this review, I will discuss our understanding of H-NS with a focus on these structural elements...
December 15, 2016: Biochemical Society Transactions
https://www.readbyqxmd.com/read/27911943/enhanced-in-planta-fitness-through-adaptive-mutations-in-efpr-a-dual-regulator-of-virulence-and-metabolic-functions-in-the-plant-pathogen-ralstonia-solanacearum
#18
Anthony Perrier, Rémi Peyraud, David Rengel, Xavier Barlet, Emmanuel Lucasson, Jérôme Gouzy, Nemo Peeters, Stéphane Genin, Alice Guidot
Experimental evolution of the plant pathogen Ralstonia solanacearum, where bacteria were maintained on plant lineages for more than 300 generations, revealed that several independent single mutations in the efpR gene from populations propagated on beans were associated with fitness gain on bean. In the present work, novel allelic efpR variants were isolated from populations propagated on other plant species, thus suggesting that mutations in efpR were not solely associated to a fitness gain on bean, but also on additional hosts...
December 2016: PLoS Pathogens
https://www.readbyqxmd.com/read/27911835/two-crystal-structures-reveal-design-for-repurposing-the-c-ala-domain-of-human-alars
#19
Litao Sun, Youngzee Song, David Blocquel, Xiang-Lei Yang, Paul Schimmel
The 20 aminoacyl tRNA synthetases (aaRSs) couple each amino acid to their cognate tRNAs. During evolution, 19 aaRSs expanded by acquiring novel noncatalytic appended domains, which are absent from bacteria and many lower eukaryotes but confer extracellular and nuclear functions in higher organisms. AlaRS is the single exception, with an appended C-terminal domain (C-Ala) that is conserved from prokaryotes to humans but with a wide sequence divergence. In human cells, C-Ala is also a splice variant of AlaRS...
November 28, 2016: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/27911097/performance-of-an-anaerobic-membrane-bioreactor-in-which-granular-sludge-and-dynamic-filtration-are-integrated
#20
Jixiang Yang, Xin Ji, Lunhui Lu, Hua Ma, Youpeng Chen, Jinsong Guo, Fang Fang
To alleviate the fouling of a filter, simple substrates, dynamic filtration, and granular sludge were applied in an anaerobic membrane bioreactor (AnMBR). The results showed that under a transmembrane pressure < 20 kPa, the filter flux ranged between 15 and 20 l (m(-2) h)(-1) for a period of 30 days. The flux was higher than the typical flux of AnMBRs with conventional membranes and most current dynamic filters. In addition, the low cost of the filter avoided the need for a higher flux. Moreover, a stable granular sludge bed, which consumed all volatile fatty acids, was maintained...
December 2, 2016: Biofouling
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