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SOS response

Thea S B Møller, Gang Liu, Anders Boysen, Line E Thomsen, Freja L Lüthje, Sisse Mortensen, Jakob Møller-Jensen, John E Olsen
Horizontal gene transfer (HGT) is the major mechanism responsible for spread of antibiotic resistance. Antibiotic treatment has been suggested to promote HGT, either by directly affecting the conjugation process itself or by selecting for conjugations subsequent to DNA transfer. However, recent research suggests that the effect of antibiotic treatment on plasmid conjugation frequencies, and hence the spread of resistance plasmids, may have been overestimated. We addressed the question by quantifying transfer proteins and conjugation frequencies of a blaCTX-M-1 encoding IncI1 resistance plasmid in Escherichia coli MG1655 in the presence and absence of therapeutically relevant concentrations of cefotaxime (CTX)...
2017: Frontiers in Microbiology
ChinweU Chukwudi, Liam Good
The hok/sok locus has been shown to enhance the growth of bacteria in adverse growth conditions such as high temperature, low starting-culture densities and antibiotic treatment. This is in addition to their well-established plasmid-stabilization effect via post-segregational killing of plasmid-free daughter cells. It delays the onset of growth by prolonging the lag phase of bacterial culture, and increases the rate of exponential growth when growth eventually begins. This enables the cells adapt to the prevailing growth conditions and enhance their survival in stressful conditions...
December 9, 2017: Microbial Pathogenesis
Junxin Wang, Ching-Yu Lin, Colman Moore, Anamik Jhunjhunwala, Jesse V Jokerst
The interaction between methylene blue (MB) and sodium dodecyl sulfate (SDS) has been widely studied spectroscopically, but details about their interactions are limited. Here, we combined photoacoustic (PA) imaging with nanoparticle tracking analysis (NTA) and spectroscopy to further elucidate this interaction. PA imaging of 0.05 mM MB showed a 492-fold increase in intensity upon addition of 3.47 mM SDS. Higher concentrations above SDS's critical micelle concentration (CMC) at 8.67 mM decreased the PA intensity by 54-fold...
December 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Liora Shmueli, Nadav Davidovitch, Joseph S Pliskin, Ran D Balicer, Igal Hekselman, Geva Greenfield
BACKGROUND: Seeking a second-opinion (SO) is a common clinical practice that can optimize treatment and reduce unnecessary procedures and risks. We aim to characterize the composition of the population of SO seekers, their reasons for seeking a SO and choosing a specific physician, and their perceived outcomes following the SO. METHODS: A cross-sectional national telephone survey, using a representative sample of the general Israeli population (n = 848, response rate = 62%)...
December 8, 2017: Israel Journal of Health Policy Research
Luciana Besedovsky, Hong-Viet V Ngo, Stoyan Dimitrov, Christoph Gassenmaier, Rainer Lehmann, Jan Born
Sleep is essential for health. Slow wave sleep (SWS), the deepest sleep stage hallmarked by electroencephalographic slow oscillations (SOs), appears of particular relevance here. SWS is associated with a unique endocrine milieu comprising minimum cortisol and high aldosterone, growth hormone (GH), and prolactin levels, thereby presumably fostering efficient adaptive immune responses. Yet, whether SWS causes these changes is unclear. Here we enhance SOs in men by auditory closed-loop stimulation, i.e., by delivering tones in synchrony with endogenous SOs...
December 7, 2017: Nature Communications
A S Vasilchenko, A V Vasilchenko, T M Pashkova, M P Smirnova, N I Kolodkin, I V Manukhov, G B Zavilgelsky, E A Sizova, O L Kartashova, A S Simbirtsev, E A Rogozhin, G K Duskaev, M V Sycheva
Natural peptides with antimicrobial activity are extremely diverse, and peptide synthesis technologies make it possible to significantly improve their properties for specific tasks. Here, we investigate the biological properties of the natural peptide indolicidin and the indolicidin-derived novel synthetic peptide In-58. In-58 was generated by replacing all tryptophan residues on phenylalanine in D-configuration; the α-amino group in the main chain also was modified by unsaturated fatty acid. Compared with indolicidin, In-58 is more bactericidal, more resistant to proteinase K, and less toxic to mammalian cells...
December 2017: Journal of Peptide Science: An Official Publication of the European Peptide Society
Yoshiharu Okuno, Shinsuke Marumoto, Mitsuo Miyazawa
Pinocembrin (1) and cardamonin (2) from Sozuku showed a suppressive effect on umu gene expression of SOS response in Salmonella typhimurium TA1535/pSK1002 against the mutagen furylfuramide. Compounds 1 and 2 suppressed 52% and 36% of SOS-inducing activity at a concentration of 0.20 μmol/mL. The ID50 value of 1 was 0.18 μmol/mL. These compounds showed the suppression of 2-amino-3,4-dimethylimidazo-[4,5-f]quinolone (MeIQ) and UV irradiation-induced SOS response. Pinostrobin (3) and 5,7-dimethoxyflavanone (4), methyl ethers of 1, showed similar activity to 1 against MeIQ-induced SOS response, but that of furylfuramide and UV irradiation were decreased...
November 28, 2017: Natural Product Research
E Shun-Mei, Jian-Ming Zeng, Hui Yuan, Yang Lu, Ren-Xin Cai, Cha Chen
Bacteria are subjected to sub-minimal inhibitory concentrations (sub-MIC) of antibiotics in various niches where the low-dosage treatment plays a key role in antibiotic resistance selection. However, the mechanism of sub-MIC of antibiotics on the resistant gene transfer is largely unknown. Here, we used Escherichia coli SM10λpir in which the RP4 plasmid was chromosomally-integrated as the donor strain, to investigate the effects of sub-MIC of Ciprofloxacin(Cip) or Levofloxacin(Lev) on conjugational transfer of mobilisable plasmid-pUCP24T from SM10λpir to Pseudomonas aeruginosa...
November 23, 2017: Microbial Pathogenesis
Emanuele Frontoni, Rama Pollini, Paola Russo, Primo Zingaretti, Graziano Cerri
The aim of this paper is to present the main results of HDOMO, an Ambient Assisted Living (AAL) project that involved 16 Small and Medium Enterprises (SMEs) and 2 research institutes. The objective of the project was to create an autonomous and automated domestic environment, primarily for elderly people and people with physical and motor disabilities. A known and familiar environment should help users in their daily activities and it should act as a virtual caregiver by calling, if necessary, relief efforts...
November 13, 2017: Sensors
Juan de Dios Barajas-Lopez, Jose Ramon Moreno, Francisco M Gamez-Arjona, Jose M Pardo, Matleena Punkkinen, Jian-Kang Zhu, Francisco J Quintero, Hiroaki Fujii
Sucrose-Non-Fermenting1-related protein kinases (SnRKs) are important for plant growth and stress responses. This family has three clades: SnRK1, SnRK2, and SnRK3. Although plant SnRKs are thought to be activated by upstream kinases, the overall mechanism remains obscure. Geminivirus Rep-Interacting Kinase (GRIK)1 and GRIK2 phosphorylate SnRK1s, which are involved in sugar/energy sensing, and the grik1-1 grik2-1 double mutant shows growth retardation under regular growth conditions. In this study, we established another Arabidopsis mutant line harbouring a different allele of gene GRIK1 (grik1-2 grik2-1) that grows similarly to the wild type, enabling us to evaluate the function of GRIKs under stress conditions...
November 1, 2017: Plant Journal: for Cell and Molecular Biology
Mark A Webber, Michelle M C Buckner, Liam S Redgrave, Gyles Ifill, Lesley A Mitchenall, Carly Webb, Robyn Iddles, Anthony Maxwell, Laura J V Piddock
Objectives: Cross-resistance between antibiotics and biocides is a potentially important driver of MDR. A relationship between susceptibility of Salmonella to quinolones and triclosan has been observed. This study aimed to: (i) investigate the mechanism underpinning this; (ii) determine whether the phenotype is conserved in Escherichia coli; and (iii) evaluate the potential for triclosan to select for quinolone resistance. Methods: WT E. coli, Salmonella enterica serovar Typhimurium and gyrA mutants were used...
October 1, 2017: Journal of Antimicrobial Chemotherapy
Begonia Fudrini Olivencia, Andreas U Müller, Bernd Roschitzki, Sibylle Burger, Eilika Weber-Ban, Frank Imkamp
Two genes, pafB and pafC, are organized in an operon with the Pup-ligase gene pafA, which is part of the Pup-proteasome system (PPS) present in mycobacteria and other actinobacteria. The PPS is crucial for Mycobacterium tuberculosis resistance towards reactive nitrogen intermediates (RNI). However, pafB and pafC apparently play only a minor role in RNI resistance. To characterize their function, we generated a pafBC deletion in Mycobacterium smegmatis (Msm). Proteome analysis of the mutant strain revealed decreased cellular levels of various proteins involved in DNA damage repair, including recombinase A (RecA)...
October 25, 2017: Scientific Reports
Vineet Kumar, Rajesh Kumar Mishra, Gursharan Kaur, Dipak Dutta
The oxidative stress that evolves under cobalt and nickel exposure is thought to exert toxicity, though the exact routes of such metal poisoning remain ambiguous. We revisited the metal toxicity in Escherichia coli to show that cobalt and nickel exposure at levels as low as 0.5 and 1 mM, respectively, visibly inhibits growth. We also observed that acidic conditions aggravated, while alkaline conditions alleviated the metal toxicity. Besides, 1 mM manganese, which is non-cytotoxic, as judged by the growth of E...
November 15, 2017: Metallomics: Integrated Biometal Science
Francesco Conti, Stefano Balducci, Luca Pugliese, Valeria D'Errico, Martina Vitale, Elena Alessi, Gerardo Salerno, Carla Iacobini, Stefano Menini, Lucilla Bollanti, Antonio Nicolucci, Giuseppe Pugliese
OBJECTIVE: Quantitative ultrasound (QUS) provides an estimate of bone mineral density (BMD) and also evaluates bone quality, which has been related to increased fracture risk in people with diabetes. This study aimed at assessing the correlates of calcaneal QUS parameters in diabetic subjects encompassing various degrees of micro and macrovascular complications and a wide-range of peripheral nerve function. METHODS: Four hundred consecutive diabetic patients were examined by QUS to obtain values of broadband ultrasound attenuation (BUA), the speed of sound (SOS), quantitative ultrasound index (QUI), and BMD...
2017: Journal of Diabetes Research
Jovana Jovanović, Stoimir Kolarević, Aleksandra Milošković, Nataša Radojković, Vladica Simić, Biljana Dojčinović, Margareta Kračun-Kolarević, Momir Paunović, Jovana Kostić, Karolina Sunjog, Jovana Timilijić, Jelena Djordjević, Zoran Gačić, Bojana Žegura, Branka Vuković-Gačić
The Velika Morava River is the greatest national Serbian river and the significant tributary of the Danube River. The major problems in the Velika Morava River Basin (VMRB) represent untreated industrial and municipal wastewaters. In this study, the level of genotoxic potential at the sites along the VMRB was evaluated by parallel in vitro and in situ approach. Within in vitro testing, genotoxicity of native water samples collected from the sites in VMRB was evaluated by SOS/umuC test on Salmonella typhimurium TA1535/pSK1002 and by the comet assay on HepG2 cells...
October 19, 2017: Science of the Total Environment
John Coutsouvelis, Sharon Avery, Michael Dooley, Carl Kirkpatrick, Andrew Spencer
PURPOSE: Defibrotide is an agent used to treat sinusoidal obstruction syndrome (SOS/VOD) in patients undergoing haemopoietic stem cell transplantation. The aim of this study was to evaluate the effectiveness of defibrotide used within institutional guidelines for the treatment of SOS/VOD in patients undergoing haemopoietic stem cell transplantation (HSCT). METHODS: Data for 23 patients was retrospectively reviewed to evaluate the effectiveness of defibrotide and the utility of response criteria to direct therapy as specified within institution guidelines...
October 11, 2017: Supportive Care in Cancer: Official Journal of the Multinational Association of Supportive Care in Cancer
Soo-Mi Kweon, Bing Zhu, Yibu Chen, L Aravind, Shuang-Yong Xu, Douglas E Feldman
Enzymatic oxidation of 5-methylcytosine (5mC) in DNA by the Tet dioxygenases reprograms genome function in embryogenesis and postnatal development. Tet-oxidized derivatives of 5mC such as 5-hydroxymethylcytosine (5hmC) act as transient intermediates in DNA demethylation or persist as durable marks, yet how these alternative fates are specified at individual CpGs is not understood. Here, we report that the SOS response-associated peptidase (SRAP) domain protein Srap1, the mammalian ortholog of an ancient protein superfamily associated with DNA damage response operons in bacteria, binds to Tet-oxidized forms of 5mC in DNA and catalyzes turnover of these bases to unmodified cytosine by an autopeptidase-coupled nuclease...
October 10, 2017: Cell Reports
E Recacha, J Machuca, P Díaz de Alba, M Ramos-Güelfo, F Docobo-Pérez, J Rodriguez-Beltrán, J Blázquez, A Pascual, J M Rodríguez-Martínez
Suppression of the SOS response has been postulated as a therapeutic strategy for potentiating antimicrobial agents. We aimed to evaluate the impact of its suppression on reversing resistance using a model of isogenic strains of Escherichia coli representing multiple levels of quinolone resistance. E. coli mutants exhibiting a spectrum of SOS activity were constructed from isogenic strains carrying quinolone resistance mechanisms with susceptible and resistant phenotypes. Changes in susceptibility were evaluated by static (MICs) and dynamic (killing curves or flow cytometry) methodologies...
October 10, 2017: MBio
Camila Justino de Oliveira Barbeta, Ezequiel Moreira Gonçalves, Keila Donassolo Santos Ribeiro, Roberto Ribeiro, Everton Paulo Roman, Gil Guerra-Júnior
OBJECTIVE: To evaluate bone mass by quantitative ultrasound of the phalanges in young karate practitioners compared to a control group. METHODS: Sample composed of 162 karate practitioners (52 females) and 326 healthy controls (110 females) aged 6 to 16 years old, in Western Paraná (Southern Brazil). Weight, height, BMI, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were evaluated. BMI, AD-SoS and BTT values were converted to Z scores...
September 21, 2017: Revista Paulista de Pediatria: Orgão Oficial da Sociedade de Pediatria de São Paulo
Ingvild Flåtten, Emily Helgesen, Ida Benedikte Pedersen, Torsten Waldminghaus, Christiane Rothe, Riikka Taipale, Line Johnsen, Kirsten Skarstad
The Escherichia colidnaXE145A mutation was discovered in connection with a screen for multicopy suppressors of the temperature-sensitive topoisomerase IV mutation parE10 The gene for the clamp loader subunits τ and γ, dnaX, but not the mutant dnaXE145A , was found to suppress parE10(Ts) when overexpressed. Purified mutant protein was found to be functional in vitro, and few phenotypes were found in vivo apart from problems with partitioning of DNA in rich medium. We show here that a large number of the replication forks that initiate at oriC never reach the terminus in dnaXE145A mutant cells...
December 15, 2017: Journal of Bacteriology
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