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https://www.readbyqxmd.com/read/28893775/a-nosocomial-outbreak-of-extensively-drug-resistant-xdr-acinetobacter-baumannii-isolates-containing-blaoxa-237-encoded-on-a-plasmid
#1
Andrea M Hujer, Paul G Higgins, Susan D Rudin, Genevieve L Buser, Steven H Marshall, Kyriaki Xanthopoulou, Harald Seifert, Laura J Rojas, T Nicholas Domitrovic, P Maureen Cassidy, Margaret C Cunningham, Robert Vega, Jon P Furuno, Christopher D Pfeiffer, Zintars G Beldavs, Meredith S Wright, Michael R Jacobs, Mark D Adams, Robert A Bonomo
Carbapenem antibiotics are among the mainstay for treating infections caused by Acinetobacter baumannii, especially in the Northwest United States where carbapenem resistant A. baumannii remain relatively rare. However, between June 2012 and October 2014, an outbreak of carbapenem-resistant A. baumannii occurred in 16 patients from 5 healthcare facilities in the state of Oregon. All isolates were defined as extensively-drug resistant (XDR). MLST revealed that the isolates belonged to sequence type 2 (international clone 2, IC2), and were greater than 95% similar by rep-PCR analysis...
September 11, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28876228/hicab-toxin-antitoxin-complex-from-escherichia-coli-expression-and-crystallization
#2
Jingsi Yang, Bingshuang Xu, Zengqiang Gao, Ke Zhou, Peng Liu, Yuhui Dong, Jianjun Zhang, Quansheng Liu
Toxin-antitoxin (TA) systems are widespread in both bacteria and archaea, where they enable cells to adapt to environmental cues. TA systems play crucial roles in various cellular processes, such as programmed cell death, cell growth, persistence and virulence. Here, two distinct forms of the type II toxin-antitoxin complex HicAB were identified and characterized in Escherichia coli K-12, and both were successfully overexpressed and purified. The two proposed forms, HicAB(L) and HicAB(S), differed in the presence or absence of a seven-amino-acid segment at the N-terminus in the antitoxin HicB...
September 1, 2017: Acta Crystallographica. Section F, Structural Biology Communications
https://www.readbyqxmd.com/read/28867361/diphtheric-encephalitis-and-brain-neuroimaging-features
#3
Jen Chun Foo, Kartini Rahmat, Nazimah Ab Mumin, Mia Tuang Koh, Chin Seng Gan, Norlisah Ramli, Choong Yi Fong
We report a rare case of paediatric diphtheria complicated with encephalitis. A 6-year-old boy who did not receive his scheduled diptheria-tetanus-pertusis vaccination presented with one episode of generalised convulsive seizure. His illness was preceded by a 3day history of fever associated with enlarged exudative tonsils with a pseudomembrane. He was commenced on intravenous penicillin and oral erythromycin. However, he developed progressive encephalopathy with focal neurological deficit which required intubation on day 5 of illness...
August 31, 2017: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/28864459/rna-editing-in-bacteria-recodes-multiple-proteins-and-regulates-an-evolutionarily-conserved-toxin-antitoxin-system
#4
Dan Bar-Yaacov, Ernest Mordret, Ruth Towers, Tammy Biniashvili, Clara Soyris, Schraga Schwartz, Orna Dahan, Yitzhak Pilpel
Adenosine (A) to inosine (I) RNA editing is widespread in eukaryotes. In prokaryotes, however, A-to-I RNA editing was only reported to occur in tRNAs but not in protein-coding genes. By comparing DNA and RNA sequences of Escherichia coli, we show for the first time that A-to-I editing occurs also in prokaryotic mRNAs and has the potential to affect the translated proteins and cell physiology. We found 15 novel A-to-I editing events, of which 12 occurred within known protein-coding genes where they always recode a tyrosine (TAC) into a cysteine (TGC) codon...
September 1, 2017: Genome Research
https://www.readbyqxmd.com/read/28854732/synchronized-switching-of-multiple-toxin-antitoxin-modules-by-p-ppgpp-fluctuation
#5
Chengzhe Tian, Szabolcs Semsey, Namiko Mitarai
Toxin-antitoxin (TA) loci are widespread in bacteria including important pathogenic species. Recent studies suggest that TA systems play a key role in persister formation. However, the persistence phenotype shows only weak dependence on the number of TA systems, i.e. they are functionally redundant. We use a mathematical model to investigate the interaction of multiple TA systems in the switching between growth and persistence. We explore two scenarios: (i) TA systems are bistable and each TA system experiences its own noise and (ii) the noise in the level of common stress signal (e...
August 21, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28820009/expression-of-a-vibrio-parahaemolyticus-toxin-in-escherichia-coli-results-in-chromosomal-dna-degradation
#6
Jing Zhang, Saki Taniguchi, Hironori Ito, Kazuhiro Iiyama, Madoka Hino, Tsutomu Katayama, Makoto Kimura
A toxin-antitoxin system, vp1842/vp1843, locates within a superintegron on the Vibrio parahaemolyticus genome chromosome I whose toxin gene vp1843 encodes a DNA nicking endonuclease. We found that the vp1843 expression in Escherichia coli cells strongly induced chromosomal DNA degradation. On the basis of these observations, we discuss a possible physiological role of vp1842/vp1843 in V. parahaemolyticus.
August 18, 2017: Bioscience, Biotechnology, and Biochemistry
https://www.readbyqxmd.com/read/28802584/molecular-characterization-of-the-pa3j1-plasmid-from-the-psychrotolerant-antarctic-bacterium-pseudomonas-sp-ant_j3
#7
Krzysztof Romaniuk, Tomasz Krucon, Przemyslaw Decewicz, Adrian Gorecki, Lukasz Dziewit
The knowledge on plasmids of cold-active bacteria is highly limited. In this study, the molecular characterization of the pA3J1 plasmid of Antarctic psychrotolerant bacterium Pseudomonas sp. ANT_J3 was performed. Within this plasmid, thirteen putative open reading frames were identified. Nine of them encoded proteins involved in replication, partitioning, postsegregational elimination of plasmid-less cells (via a toxin-antitoxin system activity), multimer resolution and mobilization by conjugal transfer. These genes constitute the plasmid backbone...
August 9, 2017: Plasmid
https://www.readbyqxmd.com/read/28798741/deinococcus-radiodurans-toxin-antitoxin-mazef-dr-mediates-cell-death-in-response-to-dna-damage-stress
#8
Tao Li, Yulan Weng, Xiaoqiong Ma, Bing Tian, Shang Dai, Ye Jin, Mengjia Liu, Jiulong Li, Jiangliu Yu, Yuejin Hua
Here we identified a functional MazEF-dr system in the exceptionally stress-resistant bacterium D. radiodurans. We showed that overexpression of the toxin MazF-dr inhibited the growth of Escherichia coli. The toxic effect of MazF-dr was due to its sequence-specific endoribonuclease activity on RNAs containing a consensus 5'ACA3', and it could be neutralized by MazE-dr. The MazF-dr showed a special cleavage preference for the nucleotide present before the ACA sequence with the order by U>A>G>C. MazEF-dr mediated the death of D...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28777088/production-biophysical-characterization-and-crystallization-of-pseudomonas-putida-graa-and-its-complexes-with-grat-and-the-grata-operator
#9
Ariel Talavera, Hedvig Tamman, Andres Ainelo, San Hadǽi, Abel Garcia-Pino, Rita Hõrak, Albert Konijnenberg, Remy Loris
The graTA operon from Pseudomonas putida encodes a toxin-antitoxin module with an unusually moderate toxin. Here, the production, SAXS analysis and crystallization of the antitoxin GraA, the GraTA complex and the complex of GraA with a 33 bp operator fragment are reported. GraA forms a homodimer in solution and crystallizes in space group P21, with unit-cell parameters a = 66.9, b = 48.9, c = 62.7 Å, β = 92.6°. The crystals are likely to contain two GraA dimers in the asymmetric unit and diffract to 1...
August 1, 2017: Acta Crystallographica. Section F, Structural Biology Communications
https://www.readbyqxmd.com/read/28770009/complete-genome-sequence-of-a-commensal-bacterium-hafnia-alvei-cba7124-isolated-from-human-feces
#10
Hye Seon Song, Joon Yong Kim, Yeon Bee Kim, Myeong Seon Jeong, Jisu Kang, Jin-Kyu Rhee, Joseph Kwon, Ju Suk Kim, Jong-Soon Choi, Hak-Jong Choi, Young-Do Nam, Seong Woon Roh
BACKGROUND: Members of the genus Hafnia have been isolated from the feces of mammals, birds, reptiles, and fish, as well as from soil, water, sewage, and foods. Hafnia alvei is an opportunistic pathogen that has been implicated in intestinal and extraintestinal infections in humans. However, its pathogenicity is still unclear. In this study, we isolated H. alvei from human feces and performed sequencing as well as comparative genomic analysis to better understand its pathogenicity. RESULTS: The genome of H...
2017: Gut Pathogens
https://www.readbyqxmd.com/read/28737000/chemoprofile-and-functional-diversity-of-fungal-and-bacterial-endophytes-and-role-of-ecofactors-a-review
#11
REVIEW
Aiyatullah Shah, Qazi Parvaiz Hassan, Saleem Mushtaq, Aabid Manzoor Shah, Aehtesham Hussain
Endophytes represent a hidden world within plants. Almost all plants that are studied harbor one or more endophytes, which help their host to survive against pathogens and changing adverse environmental conditions. Fungal and bacterial endophytes with distinct ecological niches show important biological activities and ecological functions. Their unique physiological and biochemical characteristics lead to the production of niche specific secondary metabolites that may have pharmacological potential. Identification of specific secondary metabolites in adverse environment can also help us in understanding mechanisms of host tolerance against stress condition such as biological invasions, salt, drought, temperature...
July 24, 2017: Journal of Basic Microbiology
https://www.readbyqxmd.com/read/28732463/common-and-phylogenetically-widespread-coding-for-peptides-by-bacterial-small-rnas
#12
Robin C Friedman, Stefan Kalkhof, Olivia Doppelt-Azeroual, Stephan A Mueller, Martina Chovancová, Martin von Bergen, Benno Schwikowski
BACKGROUND: While eukaryotic noncoding RNAs have recently received intense scrutiny, it is becoming clear that bacterial transcription is at least as pervasive. Bacterial small RNAs and antisense RNAs (sRNAs) are often assumed to be noncoding, due to their lack of long open reading frames (ORFs). However, there are numerous examples of sRNAs encoding for small proteins, whether or not they also have a regulatory role at the RNA level. METHODS: Here, we apply flexible machine learning techniques based on sequence features and comparative genomics to quantify the prevalence of sRNA ORFs under natural selection to maintain protein-coding function in 14 phylogenetically diverse bacteria...
July 21, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28729858/toxin-antitoxin-systems-in-estuarine-synechococcus-strain-cb0101-and-their-transcriptomic-responses-to-environmental-stressors
#13
David Marsan, Allen Place, Daniel Fucich, Feng Chen
Bacterial toxin-antitoxin (TA) systems are genetic elements composed of a toxin gene and its cognate antitoxin, with the ability to regulate growth. TA systems have not previously been reported in marine Synechococcus or Prochlorococcus. Here we report the finding of seven TA system pairs (Type II) in the estuarine Synechococcus CB0101, and their responses of these TA genes to under different stress conditions, which include; nitrogen and phosphate starvation, phage infection, zinc toxicity, and photo-oxidation...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28726719/sima-cells-for-a-serotype-specific-and-sensitive-cell-based-neutralization-test-for-botulinum-toxin-a-and-e
#14
Nicola Bak, Shalini Rajagopal, Paul Stickings, Dorothea Sesardic
Botulinum toxins (BoNTs), of which there are seven serotypes, are among the most potent neurotoxins, with serotypes A, B and E causing human botulism. Antitoxins form the first line of treatment for botulism, and functional, highly sensitive in vitro methods for toxin neutralization are needed to replace the current in vivo methods used for determination of antitoxin potency. In this preliminary proof of concept study, we report the development of a neutralization test using the neuroblastoma SiMa cell line...
July 20, 2017: Toxins
https://www.readbyqxmd.com/read/28724903/co-expression-network-analysis-of-toxin-antitoxin-loci-in-mycobacterium-tuberculosis-reveals-key-modulators-of-cellular-stress
#15
Amita Gupta, Balaji Venkataraman, Madavan Vasudevan, Kiran Gopinath Bankar
Research on toxin-antitoxin loci (TA loci) is gaining impetus due to their ubiquitous presence in bacterial genomes and their observed roles in stress survival, persistence and drug tolerance. The present study investigates the expression profile of all the seventy-nine TA loci found in Mycobacterium tuberculosis. The bacterium was subjected to multiple stress conditions to identify key players of cellular stress response and elucidate a TA-coexpression network. This study provides direct experimental evidence for transcriptional activation of each of the seventy-nine TA loci following mycobacterial exposure to growth-limiting environments clearly establishing TA loci as stress-responsive modules in M...
July 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28705271/molecular-and-epidemiological-characterization-of-infant-botulism-in-beijing-china
#16
Yin Ping Dong, Wei Wang, Tao Jiang, Jin Xu, Chun Hui Han, Shao Fei Yan, Séamus Fanning, Ying Li, Xiao Chen Ma, Di Zhang, Yao Zhao, Biao Zeng, Feng Qin Li
Laboratory-based pathogen isolation, identification, and toxicity determination were performed on samples from a suspected case of infant botulism. Mice injected with cultures generated from the enema sample and ingested Powered infant formula (PIF) presented typical signs of botulism. Antitoxins to polyvalent botulinum neurotoxins (BoNTs) and monovalent BoNT type B antitoxin had protective effects. Clostridium botulinum isolated from the enema and residual PIF samples were positive for type B toxin. Pulsed-field gel electrophoresis (PFGE) revealed that the two strains of C...
June 2017: Biomedical and Environmental Sciences: BES
https://www.readbyqxmd.com/read/28700055/biological-and-molecular-properties-of-yellow-venom-of-the-amazonian-coral-snake-micrurus-surinamensis
#17
Fabiana da Rocha Oliveira, Maria das Dores Nogueira Noronha, Jorge Luis Lopez Lozano
INTRODUCTION: The coral snake Micrurus surinamensis, which is widely distributed throughout Amazonia, has a neurotoxic venom. It is important to characterize the biological and molecular properties of this venom in order to develop effective antitoxins. METHODS: Toxins from the venom of M. surinamensis were analyzed by two-dimensional polyacrylamide gel electrophoresis and their neurotoxic effects in vivo were evaluated. RESULTS AND CONCLUSIONS: Most proteins in the venom had masses < 14kDa, low phospholipase A2 activity, and no proteolytic activity...
May 2017: Revista da Sociedade Brasileira de Medicina Tropical
https://www.readbyqxmd.com/read/28696422/metagenomic-binning-of-a-marine-sponge-microbiome-reveals-unity-in-defense-but-metabolic-specialization
#18
Beate M Slaby, Thomas Hackl, Hannes Horn, Kristina Bayer, Ute Hentschel
Marine sponges are ancient metazoans that are populated by distinct and highly diverse microbial communities. In order to obtain deeper insights into the functional gene repertoire of the Mediterranean sponge Aplysina aerophoba, we combined Illumina short-read and PacBio long-read sequencing followed by un-targeted metagenomic binning. We identified a total of 37 high-quality bins representing 11 bacterial phyla and two candidate phyla. Statistical comparison of symbiont genomes with selected reference genomes revealed a significant enrichment of genes related to bacterial defense (restriction-modification systems, toxin-antitoxin systems) as well as genes involved in host colonization and extracellular matrix utilization in sponge symbionts...
July 11, 2017: ISME Journal
https://www.readbyqxmd.com/read/28691660/endoribonuclease-type-ii-toxin-antitoxin-systems-functional-or-selfish
#19
Bhaskar Chandra Mohan Ramisetty, Ramachandran Sarojini Santhosh
Most bacterial genomes have multiple type II toxin-antitoxin systems (TAs) that encode two proteins which are referred to as a toxin and an antitoxin. Toxins inhibit a cellular process, while the interaction of the antitoxin with the toxin attenuates the toxin's activity. Endoribonuclease-encoding TAs cleave RNA in a sequence-dependent fashion, resulting in translational inhibition. To account for their prevalence and retention by bacterial genomes, TAs are credited with clinically significant phenomena, such as bacterial programmed cell death, persistence, biofilms and anti-addiction to plasmids...
July 8, 2017: Microbiology
https://www.readbyqxmd.com/read/28690609/diversity-prevalence-and-longitudinal-occurrence-of-type-ii-toxin-antitoxin-systems-of-pseudomonas-aeruginosa-infecting-cystic-fibrosis-lungs
#20
Sandra B Andersen, Melanie Ghoul, Ashleigh S Griffin, Bent Petersen, Helle K Johansen, Søren Molin
Type II toxin-antitoxin (TA) systems are most commonly composed of two genes encoding a stable toxin, which harms the cell, and an unstable antitoxin that can inactivate it. TA systems were initially characterized as selfish elements, but have recently gained attention for regulating general stress responses responsible for pathogen virulence, formation of drug-tolerant persister cells and biofilms-all implicated in causing recalcitrant chronic infections. We use a bioinformatics approach to explore the distribution and evolution of type II TA loci of the opportunistic pathogen, Pseudomonas aeruginosa, across longitudinally sampled isolates from cystic fibrosis lungs...
2017: Frontiers in Microbiology
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